Pediatric Anesthesia ISSN 1155-5645
REVIEW ARTICLE
Are new supraglottic airway devices, tracheal tubes and airway viewing devices cost-effective? Simon J. Slinn, Stephen R. Froom, Mark R. W. Stacey & Christopher D. Gildersleve Department of Anaesthetics and Intensive Care Medicine, University Hospital of Wales, Cardiff, UK
Keywords child; devices; airway device; laryngoscopes Correspondence Christopher D. Gildersleve, Department of Anaesthetics and Intensive Care Medicine, University Hospital of Wales, Heath Park, Cardiff CF14 4XW, UK Email: [email protected] Section Editor: Neil Morton Accepted 3 October 2014 doi:10.1111/pan.12564
Summary Over the past two decades, a plethora of new airway devices has become available to the pediatric anesthetist. While all have the laudable intention of improving patient care and some have proven clinical benefits, these devices are often costly and at times claims of an advantage over current equipment and techniques are marginal. Supraglottic airway devices are used in the majority of pediatric anesthetics delivered in the UK, and airway-viewing devices provide an alternative for routine intubation as well as an option in the management of the difficult airway. Yet hidden beneath the convenience of the former and the technology of the latter, the impact on basic airway skills with a facemask and the lack of opportunities to fine-tune the core skill of intubation represent an unrecognised and unquantifiable cost. A judgement on this value must be factored into the absolute purchase cost and any potential benefits to the quality of patient care, thus blurring any judgement on costeffectiveness that we might have. An overall value on cost-effectiveness though not in strict monetary terms can then be ascribed. In this review, we evaluate the role of these devices in the care of the pediatric patient and attempt to balance the advantages they offer against the cost they incur, both financial and environmental, and in any quality improvement they might offer in clinical care.
Introduction In this review we examine the history, development and current usage of supraglottic airway devices, tracheal tubes and airway viewing devices in order to assess the impact and value of these tools in our practice of pediatric anesthesia. With each device there are pros and cons that may be explored and an understanding of these will help to give a value judgement on their cost and clinical effectiveness. Supraglottic airway devices From its inception, the laryngeal mask airway (1) has revolutionized the art of airway management. Where facemasks were previously used, Supraglottic Airway devices (SADs) are now in common use, freeing up the hands of the anesthetist to carry out other tasks. 20
Since the design patent of the classic laryngeal mask airway expired in 2003 an ever-increasing number of SADs have become available, each competing with this classic design. SADs can be classified into first-generation devices, a simple airway tube that sits above the glottis, and second-generation devices, SADs that have an additional drainage tube (2). While a plethora of different SADs is now available, the classic laryngeal mask airway has the greatest body of evidence to support its use in children (3–5). The flexible laryngeal mask airway, a flexible version of the classic laryngeal mask airway and available down to size 2, is used in upper airway surgery and in particular for tonsil and adenoid surgery. It may be more difficult to insert if poor or incorrect technique is used; however, it has been shown to perform as well as the classic laryngeal mask airway (6,7). The perceived advantages of improved esophageal and pharyngeal © 2014 John Wiley & Sons Ltd Pediatric Anesthesia 25 (2015) 20–26
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seal and the presence of a drainage tube integral to second-generation devices may offer a relative reduction in aspiration risk though this would be difficult to prove. A survey of members of the Association of Paediatric Anaesthetists of Great Britain and Ireland (APAGBI) demonstrated that the classic laryngeal mask airway and the flexible laryngeal mask airway are the first choice SADs among respondents but also suggested a conservatism of practice with the majority preferring to use a first-generation device (8). This mirrors evidence published in 2010 from the NAP4 census of UK-wide practice showing that only 10% of SADs used were either an i-gel or pro-seal laryngeal mask airway (9). The pro-seal laryngeal mask airway has been available in pediatric sizes since 2005 and in the UK since 2007 (10). Comparative studies with the classic laryngeal mask airway, demonstrate that the pro-seal laryngeal mask airway is equal to the classic laryngeal mask airway in all aspects of airway maintenance and superior to the classic laryngeal mask airway with regards to providing significantly higher oropharyngeal pressures (11– 17). Of the remaining SADs, all of which are relatively new to pediatric anesthetic practice, there is little evidence to suggest that these devices are clinically superior to the classic laryngeal mask airway or pro-seal laryngeal mask airway (18–26), and evidence to support their efficacy is often absent or inadequate (10). SADs have a flexibility of roles in pediatric difficult airway management. Not only are they an alternative to a conventional oropharyngeal airway, but they also offer a source of rescue after failure with mask ventilation or tracheal intubation. They have been shown to bypass certain upper airway obstructions (27). Perhaps most significantly, they provide a stable conduit for fibreoptic intubation, particularly in the syndromic child, where the dual function of the physical maintenance of the airway with maintenance of anesthesia facilitates controlled and successful intubation in even the most challenging cases (28,29). For these reasons, SADs have been incorporated in an algorithm for management of the unexpected difficult pediatric airway (30) and latterly into the APAGBI Paediatric Difficult Airway guidelines (31). When a fibrescope is used to visualize and intubate the larynx via a SAD, an important factor in success is the ease of manipulation of the fibreoptic device. The silicone classic laryngeal mask airway offers less resistance to bronchoscopic manipulation when compared to single-use polyvinyl chloride (PVC) SADs (32). Such seemingly, small individual components of the difficult intubation package mark the difference between success and failure at the extremes of difficulty when dealing © 2014 John Wiley & Sons Ltd Pediatric Anesthesia 25 (2015) 20–26
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with challenging pediatric airways. It is noteworthy that the use of a PVC SAD rather than a silicone device is associated with a greater likelihood of the child having a postoperative sore throat (33). Thus with regard to manufacturing of SADs, it would seem that the reusable, silicone-manufactured classic laryngeal mask airway and pro-seal laryngeal mask airway are the premier first and second-generation SADs respectively that are currently available for use in children and represent the benchmark to which other SADs should be compared (10). The airway skill set The base airway skills of the pediatric anesthetist are holding a facemask, laryngoscopy, and intubation. Indeed before the advent of the laryngeal mask airway, anesthesia via a facemask or intubation was the simple choice for every general anesthetic. Since their introduction, SADs have become the predominant airway used when providing anesthesia to children and as experience has increased clinicians have continued to push the boundaries for their use. It is perhaps not a surprise that the pro-seal laryngeal mask airway is advocated as a safe alternative to tracheal intubation for pediatric laparoscopy (34). The simplicity of insertion and effectiveness at maintaining an airway has been the key to the success of SADs in children. But has their introduction diminished the skill set of trainee anesthetists in that basic art of maintaining a pediatric airway? This is not a new argument, in the early 1990s, when the laryngeal mask airway was in its infancy, senior anesthetists were concerned that the ability of future anesthetists to maintain a pediatric airway might suffer as a result of the arrival of the laryngeal mask airway (35,36). Whether this concern is now manifest in the modern anesthetist is most subjective and difficult to prove. So, rather than trying to prove the subjective assertion that the airway skill set has declined, it may be more productive to offer a stand-alone, coherent argument in favor of routine facemask anesthesia. Firstly, using a facemask to deliver an anesthetic is undoubtedly less invasive than a SAD or tracheal tube. In addition, the evidence for a SAD providing a better airway compared to a facemask is equivocal (37,38). This would suggest that in the spontaneously breathing child, the only benefit of the SAD is that it frees up the hands of the anesthetist, hardly a ringing endorsement for a technique that is now used in the majority of pediatric anesthetics. Secondly, higher rates of complications are seen with the use of smaller sized SADs (4), this may be due to sizing issues or poor technique. Additionally, increased gas leakage is noted 21
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at lower airway pressures when using a SAD in infants compared to older children (12), thus raising doubts regarding the efficacy and safety of positive pressure ventilation via a SAD in infants and younger children. Thirdly, the natural tendency when a cuff leak is heard is to either change the SAD or overinflate the cuff increasing the chance of upper airway damage (39). It is imperative therefore that cuff pressures are measured in all cases. Finally, the art of holding and maintaining a pediatric airway is a skill that only comes with practice and requires muscle memory and endurance. The goal should be to become an expert in this skill and not see it as a brief stepping-stone to the attractions of SAD insertion. It is our view that you cannot put a price on the simple skill of holding a facemask. Cuffed tracheal tubes The uncuffed vs cuffed tracheal tube (TT) debate has raged in pediatric anesthesia since 1990s. Many institutions routinely use uncuffed TTs in children under the age of 8 years and arguments for this stance are commonly cited (40,41). The hypothesis that uncuffed TTs provide a good seal at the cricoid cartilage is based on the erroneous assumption that the cartilage is circular, whereas it is in fact an elliptical structure (42). Therefore to prevent a large leak from an uncuffed TT, the tube needs to have a relatively large external diameter and paradoxically, this will cause pressure on the narrower lateral walls of the cricoid with the consequent risk of mucosal damage. No studies to date have demonstrated increased airway mucosal damage from cuffed TTs, provided the appropriate sized TT is selected and cuff pressure is measured (41). There are several advantages of using a cuffed TT in all children, these include: the avoidance of repeated attempts at laryngoscopy and intubation, reduction in aspiration risk, and improved reliability of end-tidal gas analysis. In addition, lower gas flows may be used without the intentional leak in the system, reducing both anesthetic agent cost and contamination of the operating theater environment with anesthetic gases (40). Modern high volume, low-pressure cuffed tracheal tubes such as the Microcuffâ PET (Kimberly-Clark, Health Care, Atlanta, GA, USA) have been shown to demonstrate all these advantages with no increase in the risk of postextubation stridor (43). Given the lack of evidence of harm caused by cuffed tracheal tubes and the added advantages that a cuffed tube may offer, it is unfortunate that it is unlikely to become the TT of choice of the pediatric anesthetist until the unit cost is closer to that of the uncuffed variety. Using a direct cost comparison is flawed however. 22
There is a consistent finding in comparative studies that more uncuffed than cuffed TTs are used per case, as there is no need to change a cuffed tube due to excess leak. In addition, the cost saving of lower gas flows and reduced volatile agent cost should be judged against the initial outlay for a cuffed TT, thus balancing somewhat the cost comparison (41). Airway viewing devices The advent of videolaryngoscopy has seen a step change in the approach to intubation in the normal child and has provided a range of options for management of the difficult airway. Typically, these devices have a high-resolution digital camera located close to the tip of the blade, which, with its wide angle of view allows the user to see around corners. They are complimented by displays of varying optical quality. Four devices have established themselves for use in children 12 mm (44), which limits its universal applicability. There is some evidence using the original fully disposable version of the device to suggest that Airtraqâ decreases intubation time and number of intubation attempts in normal children compared with conventional laryngoscopy (50,51), though there are significant limitations with these small studies. The adult sizes of the Airtraq device can now be complimented with a Wi-Fi camera which allows real-time sharing of images and video recording of intubations with iPadâ, iPhoneâ and PC. The TruView PCDâ Infant has a prism and lens system that provides a 46° angle of refraction. The device also has a port through which oxygen can be injected; this acts as an antifogging mechanism as well as increasing the oxygen fraction in the airway during intubation (44). Four pediatric sizes are available, facilitating intubation from the sub 1-kg neonate through to the teenage years. The height of the blade is 8 mm, placing it between the Storz and GlideScope blades for ease of access when mouth opening is small. Laryngeal views are equivalent to that of direct laryngoscopy, but a longer time to intubation is noted (52). The videolaryngoscope, literally, provides a new view in the world of laryngoscopy. It is a powerful tool for teaching, allowing the teacher to see what the operator © 2014 John Wiley & Sons Ltd Pediatric Anesthesia 25 (2015) 20–26
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is viewing (53). It provides options for intubation of both normal and difficult airways and, for example, offers a new approach to tracheal tube exchange in the intensive care environment. As a product that started life as an aid for difficult intubation, there is now ingress into the world of routine direct laryngoscopy, and the videolaryngoscope might now be advocated as a first line device for routine intubation. A laryngoscopic view previously confined to the operator is now available to all on screen, tablet, phone, and computer both within the anesthetic room and beyond using Wi-Fi connectivity. Are we now obliged to record each and every intubation and include this evidence in the anesthetic record of every patient as irrefutable evidence of tracheal tube position to prevent subsequent litigation? What then the role of the conventional laryngoscope? It is important to remember that in the clamor for this new technology that the art of laryngoscope use is a fundamental anesthetic skill. It is reliable, reproducible and low-tech. Once the art is mastered, as with riding a bicycle, it is the same art across the wide range of conventional laryngoscopes that are used in pediatrics. What price the loss of this skill if we neither teach it correctly nor practice until we achieve mastery? Mastery of this core skill must be a prerequisite to moving on to more sophisticated airway tools. The videolaryngoscope is a very different animal; each needs to be used in its own individual and very idiosyncratic way. For example, the Storz device looks and feels almost like a conventional laryngoscope and indeed is used in almost the same way, whereas the Airtraq device is far removed from this ‘norm’. Each device has an optimum technique of use that needs to be learnt and practised. An evaluation as to which is ‘best’ for all situations and intubations is actually counterproductive as all offer a unique option. While it is evident that videolaryngoscopes do have an important role in modern anesthetic practice, it is difficult to argue that they should replace the conventional laryngoscope. A metaanalysis comparing a range of pediatric videolaryngoscopes and direct laryngoscopes demonstrated improved glottic visualization with videolaryngoscopes in normal and difficult airways. However, this advantage is offset by a higher incidence of failure and a longer time to intubation (54). If we analyze difficult airway use in isolation, then the fraction of cases that actually need a videolaryngoscope to achieve successful intubation is tiny. Given that the unit cost of any of these devices is several thousand pounds that outlay may be difficult to justify. The natural endpoint is that we then become dependent on the reliability of complex technology to perform an easy psychomotor task. The conventional laryngoscope may rest easy for now. 23
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Disposability and variant Creutzfeldt-Jakob disease When concerns regarding the risk of the Transmissible Spongiform Encephalopathies (TSEs) became apparent the UK Department of Health (DoH) published guidance which specified that all equipment for tonsillectomy and adenoidectomy should be disposable (55). This guidance was rooted in concern that cross-contamination to healthy individuals may occur from surgical equipment used on patients with latent disease as the prion proteins were found to be highly concentrated within the tonsil lymphoid tissue. The Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland endorsed these guidelines and recommended using single-use airway devices, where such devices were as reliable and safe as reusable alternatives, to minimize the risk of transmission of prion disease (56). In particular, it highlighted that all airway devices, including SADs used for tonsillectomy and/or adenoidectomy should be discarded after use and not used again. In all other cases, where prion transmission is not a risk reusable SADs should be sterilised. This advice is based on evidence that microscopic traces of tissue can remain on surgical instruments after washing, autoclaving, and disinfection and that routine methods for cleaning SADs do not completely remove protein deposits (57–59). Protein cross-contamination occurs during batch cleaning and autoclaving (60) and furthermore, sterilisation methods do not denature prions (61). Following release of this guidance, there was a proliferation of single-use surgical and anesthetic equipment accompanied by concerns regarding their quality and efficacy (56). After increased morbidity was shown when using disposable surgical instruments, the DoH reversed its decision with regard to surgical equipment, but kept the guideline in place for all anesthetic equipment (62), which remains to this day. While increased morbidity with respect to surgery is relatively easy to demonstrate with easy to audit outcomes: blood loss, rates of return to theater, and incidence of primary and secondary hemorrhage, no such easy outcome parameters exist in the clinical evaluation of airway equipment. So, despite one of several reviews demonstrating that single-use laryngoscope blades severely underperformed compared to their reusable counterparts (63), the lack of quantifiable harm to patients reduces the impact of such reviews. It is reasonable to argue that anesthetists should balance the risk of transmitting Variant Creutzfeldt-Jakob disease (vCJD) against the use of inferior airway equipment (64). Thus far, there are no proven cases of vCJD transmission via airway equipment, and this is perhaps not
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surprising given that analysis of over 63 000 tonsil specimens found no presence of the pathogenic form of the prion protein (65). Data from The National CJD Research and Surveillance Unit, which report deaths attributable to vCJD, report only one case since January 2012 compared with a peak incidence of 28 in 2000 and from a projection of a year on year increase in reported cases the incidence has fallen (66). Some scepticism among anesthetists regarding the transmission of vCJD via reusable equipment is revealed in the results of a survey of UK practice looking at compliance with the DoH guideline on the use of disposable airway equipment for tonsillectomy. Fifty five percent of responders disagreed with the guideline, and full compliance was only seen in 16% of responders (67). With a lack of evidence to suggest that reusable airway equipment that is suitably decontaminated poses a risk to patients, and in light of the absence of pathogenic prion protein in tonsil specimens where does this leave existing guidance with respect to the use of single-use airway devices in adenoid and tonsil surgery? And if the patient safety argument holds for this subset of patients, then the driver for single-use equipment across all other procedures is weakened, the argument distilling to one of cost. It is difficult to directly compare the cost of reusable devices with single-use alternatives. With the increasing availability of a plethora of single-use versions, the unit cost is a fraction of that of the reusable classic laryngeal mask airway. While the manufacturer recommendations indicate that the classic laryngeal mask airway may be reused up to 40 times, tests indicate this lifespan could safely be increased to 60 uses before failing the recommended preuse tests (68). The total cost of the classic laryngeal mask airway then has to take into account cost of sterilisation per use. While the up-front cost of a plastic SAD is small, the hidden cost lies in the consequent disposal. An estimated 500 million SADs have been used worldwide up to 2006 (69), antedating a surge in single-use SAD manufacture that we have seen in recent years. Approximately 85 000 tons of PVC medical devices are used in Europe annually and given that recycling is not an option the default method of disposal is incineration. A comparison of the environmental impact of life cycles of reusable and disposable SADs strongly favors the use of reusable devices (70). Indeed, it can be argued that the continued use of reusable products is integral to a practice of ‘Sustainable Anesthesia’ (71). Given the superiority in performance and smaller environmental cost of reusable SADs, these remain a more cost-effective option than single-use SADs.
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Conclusions The modern trend for disposable airway devices is as much driven by aesthetics and market demands for single patient, single-use equipment as evidence that reusable airway devices carry any more than a tiny risk of disease transfer. However, with demands for patient safety overtly paramount, this trend will not be reversed despite the performance advantages and lower wider environmental cost of, in particular, reusable SADs. Here, the NHS has chosen arguably the lesser cost-effective option. The one disposable success story, that of the cuffed tracheal tube has had limited take-up, ironically due to cost despite it’s clinical effectiveness. Airway viewing devices represent the future of laryngoscopy but at considerable up-front monetary cost and the potential longer-term cost to our core skill, use of
the conventional laryngoscope. This threat to one part of our skill set is amplified by the overwhelming use of SADs in clinical practice and the loss of the art of facemask anesthesia. These twin threats represent the true costs of this advance in airway technology. Perhaps the final arbiter of cost-effectiveness will be the quality and safety of patient care. Time will be our judge. Acknowledgments No ethical approval was needed in production of this manuscript. This research was carried out without funding. Conflict of interest The authors declare no conflict of interest.
References 1 Brain AI. The laryngeal mask - a new concept in airway management. Br J Anaesth 1983; 55: 801–805. 2 Miller DM. A proposed classification and scoring system for supraglottic sealing airways: a brief review. Anesth Analg 2004; 99: 1553–1559. 3 Mason DG, Bingham RM. The laryngeal mask airway in children. Anaesthesia 1990; 45: 760–763. 4 Lopez-Gil M, Brimacombe J, Alvarez M. Safety and efficacy of the laryngeal mask airway. Anaesthesia 1996; 51: 969–972. 5 Naguib ML, Streetman DS, Clifton S et al. Use of laryngeal mask airway in flexible bronchoscopy in infants and children. Pediatr Pulmonol 2005; 39: 56–63. 6 George JM, Sanders GM. The reinforced laryngeal mask in paediatric outpatient dental surgery. Anaesthesia 1999; 54: 546–551. 7 Flynn P, Ahmed FB, Mitchell V et al. A randomised comparison of the single use LMA Flexible with the reusable LMA Flexible in paediatric dental day-case patients. Anaesthesia 2007; 62: 1281–1284. 8 Bradley AED, White MC, Engelhardt T et al. Current UK practice of pediatric supraglottic airway devices - a survey of members of the Association of Paediatric Anaesthetists of Great Britain and Ireland. Pediatr Anesth 2013; 23: 1006–1009. 9 The Royal College of Anaesthetists, The Difficult Airway Society. 4th National Audit Project: Major complications of airway management in the United Kingdom. 2011. Available at: http://www.rcoa.ac.uk/system/ files/CSQ-NAP4-Full.pdf. Accessed 23 September, 2014. 10 White MC, Cook TM, Stoddart PA. A critique of elective pediatric supraglottic airway © 2014 John Wiley & Sons Ltd Pediatric Anesthesia 25 (2015) 20–26
11
12
13
14
15
16
17
18
19
devices. Pediatr Anesth 2009; 19(Suppl. 1): 55–65. Shimbori H, Ono K, Miwa T et al. Comparison of the LMA-ProSeal and LMA-Classic in children. Br J Anaesth 2004; 93: 528–531. Goldmann K, Roettger C, Wulf H. The size 1 1/2 ProSeal laryngeal mask airway in infants: a randomized, crossover investigation with the Classic laryngeal mask airway. Anesth Analg 2006; 102: 405–410. Goldmann K, Jakob C. Size 2 ProSeal laryngeal mask airway: a randomized, crossover investigation with the standard laryngeal mask airway in paediatric patients. Br J Anaesth 2005; 94: 385–389. Goldmann K, Jakob C. A randomized crossover comparison of the size 2 1/2 laryngeal mask airway ProSeal versus laryngeal mask airway-Classic in pediatric patients. Anesth Analg 2005; 100: 1605–1610. Lopez-Gil M, Brimacombe J, Garcia G. A randomized non-crossover study comparing the ProSeal and Classic laryngeal mask airway in anaesthetized children. Br J Anaesth 2005; 95: 827–830. Lardner DRR, Cox RG, Ewen A et al. Comparison of laryngeal mask airway (LMA)Proseal and the LMA-Classic in ventilated children receiving neuromuscular blockade. Can J Anaesth 2008; 55: 29–35. Kelly F, Sale S, Bayley G et al. A cohort evaluation of the pediatric ProSeal laryngeal mask airway in 100 children. Pediatr Anesth 2008; 18: 947–951. Lee J-R, Kim M-S, Kim J-T et al. A randomised trial comparing the i-gelTM with the LMA ClassicTM in children. Anaesthesia 2012; 67: 606–611. Beylacq L, Bordes M, Semjen F et al. The Igel, a single-use supraglottic airway device
20
21
22
23
24
25
26
27
with a non-inflatable cuff and an esophageal vent: an observational study in children. Acta Anaesthesiol Scand 2009; 53: 376–379. Theiler LG, Kleine-Brueggeney M, Luepold B et al. Performance of the pediatric-sized i-gel compared with the Ambu AuraOnce laryngeal mask in anesthetized and ventilated children. Anesthesiology 2011; 115: 102–110. Beringer RM, Kelly F, Cook TM et al. A cohort evaluation of the paediatric i-gelTM airway during anaesthesia in 120 children. Anaesthesia 2011; 66: 1121–1126. Hughes C, Place K, Berg S et al. A clinical evaluation of the i-gel supraglottic airway device in children. Pediatr Anesth 2012; 22: 765–771. Jagannathan N, Sohn LE, Sawardekar A et al. A randomised trial comparing the laryngeal mask airway SupremeTM with the laryngeal mask airway UniqueTM in children. Anaesthesia 2012; 67: 139–144. Jagannathan N, Sohn LE, Sawardekar A et al. A randomised comparison of the selfpressurised air-QTM intubating laryngeal airway with the LMA UniqueTM in children. Anaesthesia 2012; 67: 973–979. Gaitini L, Carmi N, Yanovski B et al. Comparison of the CobraPLA (Cobra Perilaryngeal Airway) and the Laryngeal Mask Airway Unique in children under pressure controlled ventilation. Pediatr Anesth 2008; 18: 313–319. Szmuk P, Ghelber O, Matuszczak M et al. A prospective, randomized comparison of cobra perilaryngeal airway and laryngeal mask airway unique in pediatric patients. Anesth Analg 2008; 107: 1523–1530. Jagannathan N, Sequera-Ramos L, Sohn L et al. Elective use of supraglottic airway devices for primary airway management in
25
S.J. Slinn et al.
Are new airway devices cost-effective?
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
26
children with difficult airways. Br J Anaesth 2014; 112: 742–748. Walker RW. The laryngeal mask airway in the difficult paediatric airway: an assessment of positioning and use in fibreoptic intubation. Paediatr Anaesth 2000; 10: 53–58. Walker RWM, Allen DL, Rothera MR. A fibreoptic intubation technique for children with mucopolysaccharidoses using the laryngeal mask airway. Paediatr Anaesth 1997; 7: 421–426. Weiss M, Engelhardt T. Proposal for the management of the unexpected difficult pediatric airway. Pediatr Anesth 2010; 20: 454– 464. APAGBI. Paediatric Difficult Airway Guidelines. 2012. Available at: http://www.apagbi. org.uk/publications/apa-guidelines. Accessed 31 July, 2014. Baker PA, Brunette KEJ, Byrnes CA et al. A prospective randomized trial comparing supraglottic airways for flexible bronchoscopy in children. Pediatr Anesth 2010; 20: 831–838. Wong JGL, Heaney M, Chambers NA et al. Impact of laryngeal mask airway cuff pressures on the incidence of sore throat in children. Pediatr Anesth 2009; 19: 464–469. Sinha A, Sharma B, Sood J. ProSeal as an alternative to endotracheal intubation in pediatric laparoscopy. Pediatr Anesth 2007; 17: 327–332. Wilson IG. The laryngeal mask airway in paediatric practice. Br J Anaesth 1993; 70: 124–125. Russell D. Trainee anaesthetists and the laryngeal mask airway. Anaesthesia 1991; 46: 701. Harnett M, Kinirons B, Heffernan A et al. Airway complications in infants: comparison of laryngeal mask airway and the facemaskoral airway. Can J Anaesth 2000; 47: 315–318. Rechner JA, Loach VJ, Ali MT et al. A comparison of the laryngeal mask airway with facemask and oropharyngeal airway for manual ventilation by critical care nurses in children. Anaesthesia 2007; 62: 790–795. Ong M, Chambers NA, Hullet B et al. Laryngeal mask airway and tracheal tube cuff pressures in children: are clinical endpoints valuable for guiding inflation? Anaesthesia 2008; 63: 738–744. Khine HH, Corddry DH, Kettrick RG et al. Comparison of cuffed and uncuffed endotracheal tubes in young children during general anaesthesia. Anesthesiology 1997; 86: 627–631. Weber T, Salvi N, Orliaguet G et al. ProCon Debate: cuffed vs non-cuffed endotracheal tubes for pediatric anesthesia. Pediatr Anesth 2009; 19(Suppl. 1): 46–54. Litman RS, Weissend EE, Shibata D et al. Developmental changes of laryngeal dimensions in unparalyzed, sedated children. Anesthesiology 2003; 98: 41–45.
43 Weiss M, Dullenkopf A, Fischer JE et al. Prospective randomized controlled multicentre trial of cuffed or uncuffed endotracheal tubes in small children. Br J Anaesth 2009; 103: 867–873. 44 Holm-Knudsen R. The difficult pediatric airway-a review of new devices for indirect laryngoscopy in children younger than two years of age. Pediatr Anesth 2011; 21: 98– 103. 45 Kim J, Na H, Bae J et al. GlideScope videolaryngoscope: a randomized clinical trial in 203 paediatric patients. Br J Anaesth 2008; 101: 531–534. 46 Redel A, Karademir F, Schlitterlau A et al. Validation of the glidescope videolaryngoscope in pediatric patients. Pediatr Anesth 2009; 19: 667–671. 47 Fiadjoe JE, Gurnaney H, Dalesio N et al. A prospective randomized equivalence trial of the GlideScope Cobaltâ videolaryngoscope to traditional direct laryngoscopy in neonates and infants. Anesthesiology 2012; 116: 622– 628. 48 Fiadjoe JE, Stricker PA, Hackell RS et al. The efficacy of the Storz Miller 1 videolaryngoscope in a simulated infant difficult intubation. Anesth Analg 2009; 108: 1783–1786. 49 Vlatten A, Aucoin S, Litz S et al. A comparison of the STORZ videolaryngoscope and standard direct laryngoscopy for intubation in the Pediatric airway - a randomized clinical trial. Pediatr Anesth 2009; 19: 1102–1107. 50 Ali QE, Amir SH, Firdaus U et al. A comparative study of the efficacy of Pediatric Airtraq with conventional laryngoscope in children. Minerva Anestesiol 2013; 79: 1366– 1370. 51 Riad W, Moussa A, Wong DT. AirtraqTM versus Macintoch laryngoscope in intubation performance in the pediatric population. Saudi J Anaesth 2012; 6: 332–335. 52 Riveros R, Sung W, Sessler DI et al. Comparison of the Truview PCDTM and the GlideScopeâ videolaryngoscopes with direct laryngoscopy in pediatric patients: a randomized trial. Can J Anaesth 2013; 60: 450–457. 53 Weiss M, Schwarz U, Diller CM et al. Teaching and supervising tracheal intubation in paediatric patients using videolaryngoscopy. Paediatr Anaesth 2001; 11: 343–348. 54 Sun Y, Lu Y, Huang Y et al. Pediatric videolaryngoscope versus direct laryngoscope: a meta-analysis of randomized controlled trials. Pediatr Anesth 2014; 24: 1056– 1065. 55 Department of Health. £200 Million for NHS Equipment to Protect Patients Against Possible Variant CJD Risk. London: Department of Health, 2001. (Press release 2001/ 0012). 56 AAGBI. Infection control in anaesthesia. Anaesthesia 2008; 63: 1027–1036.
57 Coetzee GJ. Eliminating protein from reusable laryngeal mask. Anaesthesia 2003; 58: 346–352. 58 Clery G, Brimacombe J, Stone T et al. Routine cleaning and autoclaving does not remove protein deposits from reusable laryngeal mask devices. Anesth Analg 2003; 97: 1189–1191. 59 Miller DM, Youkhana I, Karunaratne WU et al. Presence of protein deposits on “cleaned” re-usable anaesthetic equipment. Anaesthesia 2001; 56: 1069–1072. 60 Richards E, Brimacombe J, Laupau W et al. Protein cross-contamination during batch cleaning and autoclaving of the ProSeal laryngeal mask airway. Anaesthesia 2006; 61: 431–433. 61 Taylor DM. Inactivation of prions by physical and chemical means. J Hosp Infect 1999; 43(Suppl.): S69–S76. 62 Department of Health. Re-Introduction of Re-Usable Instruments for Tonsil Surgery. London: Department of Health, 2001. Available at: http://webarchive.nationalarchives. gov.uk/+/www.dh.gov.uk/en/Publicationsandstatistics/Pressreleases/DH_4011629. Accessed 20 August, 2014. 63 Twigg SJ, McCormick B, Cook TM. Randomized evaluation of the performance of single-use laryngoscopes in simulated easy and difficult intubation. Br J Anaesth 2003; 90: 8–13. 64 Blunt MC, Burchett KR. Variant Creutzfeldt-Jakob disease and disposable anaesthetic equipment - balancing the risks. Br J Anaesth 2003; 90: 1–3. 65 Clewley JP, Kelly CM, Andrews N et al. Prevalence of disease related prion protein in anonymous tonsil specimens in Britain: cross sectional opportunistic survey. Br Med J 2009; 338: 1442–1448. 66 The National CJD Research and Surveillance Unit. Creutzfeldt-Jakob Disease in the UK. 2014. Available at: http://www.cjd.ed.ac.uk/. 67 Clarke MB, Forster P, Cook TM. Airway management for tonsillectomy: a national survey of UK practice. Br J Anaesth 2007; 99: 425–428. 68 Berry AM, Brimacombe JR, McManus KF et al. An evaluation of the factors influencing selection of the optimal size of laryngeal mask airway in normal adults. Anaesthesia 1998; 53: 565–570. 69 Cook TM. The classic laryngeal mask airway: a tried and tested airway. What now? Br J Anaesth 2006; 96: 149–152. 70 Eckelman M, Mosher M, Gonzalez A et al. Comparative life cycle assessment of disposable and reusable laryngeal mask airways. Anesth Analg 2012; 114: 1067–1072. 71 Ryan S, Sherman J. Sustainable anesthesia. Anesth Analg 2012; 114: 921–923.
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REVIEW ARTICLE
Are new supraglottic airway devices, tracheal tubes and airway viewing devices cost-effective? Simon J. Slinn, Stephen R. Froom, Mark R. W. Stacey & Christopher D. Gildersleve Department of Anaesthetics and Intensive Care Medicine, University Hospital of Wales, Cardiff, UK
Keywords child; devices; airway device; laryngoscopes Correspondence Christopher D. Gildersleve, Department of Anaesthetics and Intensive Care Medicine, University Hospital of Wales, Heath Park, Cardiff CF14 4XW, UK Email: [email protected] Section Editor: Neil Morton Accepted 3 October 2014 doi:10.1111/pan.12564
Summary Over the past two decades, a plethora of new airway devices has become available to the pediatric anesthetist. While all have the laudable intention of improving patient care and some have proven clinical benefits, these devices are often costly and at times claims of an advantage over current equipment and techniques are marginal. Supraglottic airway devices are used in the majority of pediatric anesthetics delivered in the UK, and airway-viewing devices provide an alternative for routine intubation as well as an option in the management of the difficult airway. Yet hidden beneath the convenience of the former and the technology of the latter, the impact on basic airway skills with a facemask and the lack of opportunities to fine-tune the core skill of intubation represent an unrecognised and unquantifiable cost. A judgement on this value must be factored into the absolute purchase cost and any potential benefits to the quality of patient care, thus blurring any judgement on costeffectiveness that we might have. An overall value on cost-effectiveness though not in strict monetary terms can then be ascribed. In this review, we evaluate the role of these devices in the care of the pediatric patient and attempt to balance the advantages they offer against the cost they incur, both financial and environmental, and in any quality improvement they might offer in clinical care.
Introduction In this review we examine the history, development and current usage of supraglottic airway devices, tracheal tubes and airway viewing devices in order to assess the impact and value of these tools in our practice of pediatric anesthesia. With each device there are pros and cons that may be explored and an understanding of these will help to give a value judgement on their cost and clinical effectiveness. Supraglottic airway devices From its inception, the laryngeal mask airway (1) has revolutionized the art of airway management. Where facemasks were previously used, Supraglottic Airway devices (SADs) are now in common use, freeing up the hands of the anesthetist to carry out other tasks. 20
Since the design patent of the classic laryngeal mask airway expired in 2003 an ever-increasing number of SADs have become available, each competing with this classic design. SADs can be classified into first-generation devices, a simple airway tube that sits above the glottis, and second-generation devices, SADs that have an additional drainage tube (2). While a plethora of different SADs is now available, the classic laryngeal mask airway has the greatest body of evidence to support its use in children (3–5). The flexible laryngeal mask airway, a flexible version of the classic laryngeal mask airway and available down to size 2, is used in upper airway surgery and in particular for tonsil and adenoid surgery. It may be more difficult to insert if poor or incorrect technique is used; however, it has been shown to perform as well as the classic laryngeal mask airway (6,7). The perceived advantages of improved esophageal and pharyngeal © 2014 John Wiley & Sons Ltd Pediatric Anesthesia 25 (2015) 20–26
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seal and the presence of a drainage tube integral to second-generation devices may offer a relative reduction in aspiration risk though this would be difficult to prove. A survey of members of the Association of Paediatric Anaesthetists of Great Britain and Ireland (APAGBI) demonstrated that the classic laryngeal mask airway and the flexible laryngeal mask airway are the first choice SADs among respondents but also suggested a conservatism of practice with the majority preferring to use a first-generation device (8). This mirrors evidence published in 2010 from the NAP4 census of UK-wide practice showing that only 10% of SADs used were either an i-gel or pro-seal laryngeal mask airway (9). The pro-seal laryngeal mask airway has been available in pediatric sizes since 2005 and in the UK since 2007 (10). Comparative studies with the classic laryngeal mask airway, demonstrate that the pro-seal laryngeal mask airway is equal to the classic laryngeal mask airway in all aspects of airway maintenance and superior to the classic laryngeal mask airway with regards to providing significantly higher oropharyngeal pressures (11– 17). Of the remaining SADs, all of which are relatively new to pediatric anesthetic practice, there is little evidence to suggest that these devices are clinically superior to the classic laryngeal mask airway or pro-seal laryngeal mask airway (18–26), and evidence to support their efficacy is often absent or inadequate (10). SADs have a flexibility of roles in pediatric difficult airway management. Not only are they an alternative to a conventional oropharyngeal airway, but they also offer a source of rescue after failure with mask ventilation or tracheal intubation. They have been shown to bypass certain upper airway obstructions (27). Perhaps most significantly, they provide a stable conduit for fibreoptic intubation, particularly in the syndromic child, where the dual function of the physical maintenance of the airway with maintenance of anesthesia facilitates controlled and successful intubation in even the most challenging cases (28,29). For these reasons, SADs have been incorporated in an algorithm for management of the unexpected difficult pediatric airway (30) and latterly into the APAGBI Paediatric Difficult Airway guidelines (31). When a fibrescope is used to visualize and intubate the larynx via a SAD, an important factor in success is the ease of manipulation of the fibreoptic device. The silicone classic laryngeal mask airway offers less resistance to bronchoscopic manipulation when compared to single-use polyvinyl chloride (PVC) SADs (32). Such seemingly, small individual components of the difficult intubation package mark the difference between success and failure at the extremes of difficulty when dealing © 2014 John Wiley & Sons Ltd Pediatric Anesthesia 25 (2015) 20–26
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with challenging pediatric airways. It is noteworthy that the use of a PVC SAD rather than a silicone device is associated with a greater likelihood of the child having a postoperative sore throat (33). Thus with regard to manufacturing of SADs, it would seem that the reusable, silicone-manufactured classic laryngeal mask airway and pro-seal laryngeal mask airway are the premier first and second-generation SADs respectively that are currently available for use in children and represent the benchmark to which other SADs should be compared (10). The airway skill set The base airway skills of the pediatric anesthetist are holding a facemask, laryngoscopy, and intubation. Indeed before the advent of the laryngeal mask airway, anesthesia via a facemask or intubation was the simple choice for every general anesthetic. Since their introduction, SADs have become the predominant airway used when providing anesthesia to children and as experience has increased clinicians have continued to push the boundaries for their use. It is perhaps not a surprise that the pro-seal laryngeal mask airway is advocated as a safe alternative to tracheal intubation for pediatric laparoscopy (34). The simplicity of insertion and effectiveness at maintaining an airway has been the key to the success of SADs in children. But has their introduction diminished the skill set of trainee anesthetists in that basic art of maintaining a pediatric airway? This is not a new argument, in the early 1990s, when the laryngeal mask airway was in its infancy, senior anesthetists were concerned that the ability of future anesthetists to maintain a pediatric airway might suffer as a result of the arrival of the laryngeal mask airway (35,36). Whether this concern is now manifest in the modern anesthetist is most subjective and difficult to prove. So, rather than trying to prove the subjective assertion that the airway skill set has declined, it may be more productive to offer a stand-alone, coherent argument in favor of routine facemask anesthesia. Firstly, using a facemask to deliver an anesthetic is undoubtedly less invasive than a SAD or tracheal tube. In addition, the evidence for a SAD providing a better airway compared to a facemask is equivocal (37,38). This would suggest that in the spontaneously breathing child, the only benefit of the SAD is that it frees up the hands of the anesthetist, hardly a ringing endorsement for a technique that is now used in the majority of pediatric anesthetics. Secondly, higher rates of complications are seen with the use of smaller sized SADs (4), this may be due to sizing issues or poor technique. Additionally, increased gas leakage is noted 21
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at lower airway pressures when using a SAD in infants compared to older children (12), thus raising doubts regarding the efficacy and safety of positive pressure ventilation via a SAD in infants and younger children. Thirdly, the natural tendency when a cuff leak is heard is to either change the SAD or overinflate the cuff increasing the chance of upper airway damage (39). It is imperative therefore that cuff pressures are measured in all cases. Finally, the art of holding and maintaining a pediatric airway is a skill that only comes with practice and requires muscle memory and endurance. The goal should be to become an expert in this skill and not see it as a brief stepping-stone to the attractions of SAD insertion. It is our view that you cannot put a price on the simple skill of holding a facemask. Cuffed tracheal tubes The uncuffed vs cuffed tracheal tube (TT) debate has raged in pediatric anesthesia since 1990s. Many institutions routinely use uncuffed TTs in children under the age of 8 years and arguments for this stance are commonly cited (40,41). The hypothesis that uncuffed TTs provide a good seal at the cricoid cartilage is based on the erroneous assumption that the cartilage is circular, whereas it is in fact an elliptical structure (42). Therefore to prevent a large leak from an uncuffed TT, the tube needs to have a relatively large external diameter and paradoxically, this will cause pressure on the narrower lateral walls of the cricoid with the consequent risk of mucosal damage. No studies to date have demonstrated increased airway mucosal damage from cuffed TTs, provided the appropriate sized TT is selected and cuff pressure is measured (41). There are several advantages of using a cuffed TT in all children, these include: the avoidance of repeated attempts at laryngoscopy and intubation, reduction in aspiration risk, and improved reliability of end-tidal gas analysis. In addition, lower gas flows may be used without the intentional leak in the system, reducing both anesthetic agent cost and contamination of the operating theater environment with anesthetic gases (40). Modern high volume, low-pressure cuffed tracheal tubes such as the Microcuffâ PET (Kimberly-Clark, Health Care, Atlanta, GA, USA) have been shown to demonstrate all these advantages with no increase in the risk of postextubation stridor (43). Given the lack of evidence of harm caused by cuffed tracheal tubes and the added advantages that a cuffed tube may offer, it is unfortunate that it is unlikely to become the TT of choice of the pediatric anesthetist until the unit cost is closer to that of the uncuffed variety. Using a direct cost comparison is flawed however. 22
There is a consistent finding in comparative studies that more uncuffed than cuffed TTs are used per case, as there is no need to change a cuffed tube due to excess leak. In addition, the cost saving of lower gas flows and reduced volatile agent cost should be judged against the initial outlay for a cuffed TT, thus balancing somewhat the cost comparison (41). Airway viewing devices The advent of videolaryngoscopy has seen a step change in the approach to intubation in the normal child and has provided a range of options for management of the difficult airway. Typically, these devices have a high-resolution digital camera located close to the tip of the blade, which, with its wide angle of view allows the user to see around corners. They are complimented by displays of varying optical quality. Four devices have established themselves for use in children 12 mm (44), which limits its universal applicability. There is some evidence using the original fully disposable version of the device to suggest that Airtraqâ decreases intubation time and number of intubation attempts in normal children compared with conventional laryngoscopy (50,51), though there are significant limitations with these small studies. The adult sizes of the Airtraq device can now be complimented with a Wi-Fi camera which allows real-time sharing of images and video recording of intubations with iPadâ, iPhoneâ and PC. The TruView PCDâ Infant has a prism and lens system that provides a 46° angle of refraction. The device also has a port through which oxygen can be injected; this acts as an antifogging mechanism as well as increasing the oxygen fraction in the airway during intubation (44). Four pediatric sizes are available, facilitating intubation from the sub 1-kg neonate through to the teenage years. The height of the blade is 8 mm, placing it between the Storz and GlideScope blades for ease of access when mouth opening is small. Laryngeal views are equivalent to that of direct laryngoscopy, but a longer time to intubation is noted (52). The videolaryngoscope, literally, provides a new view in the world of laryngoscopy. It is a powerful tool for teaching, allowing the teacher to see what the operator © 2014 John Wiley & Sons Ltd Pediatric Anesthesia 25 (2015) 20–26
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is viewing (53). It provides options for intubation of both normal and difficult airways and, for example, offers a new approach to tracheal tube exchange in the intensive care environment. As a product that started life as an aid for difficult intubation, there is now ingress into the world of routine direct laryngoscopy, and the videolaryngoscope might now be advocated as a first line device for routine intubation. A laryngoscopic view previously confined to the operator is now available to all on screen, tablet, phone, and computer both within the anesthetic room and beyond using Wi-Fi connectivity. Are we now obliged to record each and every intubation and include this evidence in the anesthetic record of every patient as irrefutable evidence of tracheal tube position to prevent subsequent litigation? What then the role of the conventional laryngoscope? It is important to remember that in the clamor for this new technology that the art of laryngoscope use is a fundamental anesthetic skill. It is reliable, reproducible and low-tech. Once the art is mastered, as with riding a bicycle, it is the same art across the wide range of conventional laryngoscopes that are used in pediatrics. What price the loss of this skill if we neither teach it correctly nor practice until we achieve mastery? Mastery of this core skill must be a prerequisite to moving on to more sophisticated airway tools. The videolaryngoscope is a very different animal; each needs to be used in its own individual and very idiosyncratic way. For example, the Storz device looks and feels almost like a conventional laryngoscope and indeed is used in almost the same way, whereas the Airtraq device is far removed from this ‘norm’. Each device has an optimum technique of use that needs to be learnt and practised. An evaluation as to which is ‘best’ for all situations and intubations is actually counterproductive as all offer a unique option. While it is evident that videolaryngoscopes do have an important role in modern anesthetic practice, it is difficult to argue that they should replace the conventional laryngoscope. A metaanalysis comparing a range of pediatric videolaryngoscopes and direct laryngoscopes demonstrated improved glottic visualization with videolaryngoscopes in normal and difficult airways. However, this advantage is offset by a higher incidence of failure and a longer time to intubation (54). If we analyze difficult airway use in isolation, then the fraction of cases that actually need a videolaryngoscope to achieve successful intubation is tiny. Given that the unit cost of any of these devices is several thousand pounds that outlay may be difficult to justify. The natural endpoint is that we then become dependent on the reliability of complex technology to perform an easy psychomotor task. The conventional laryngoscope may rest easy for now. 23
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Disposability and variant Creutzfeldt-Jakob disease When concerns regarding the risk of the Transmissible Spongiform Encephalopathies (TSEs) became apparent the UK Department of Health (DoH) published guidance which specified that all equipment for tonsillectomy and adenoidectomy should be disposable (55). This guidance was rooted in concern that cross-contamination to healthy individuals may occur from surgical equipment used on patients with latent disease as the prion proteins were found to be highly concentrated within the tonsil lymphoid tissue. The Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland endorsed these guidelines and recommended using single-use airway devices, where such devices were as reliable and safe as reusable alternatives, to minimize the risk of transmission of prion disease (56). In particular, it highlighted that all airway devices, including SADs used for tonsillectomy and/or adenoidectomy should be discarded after use and not used again. In all other cases, where prion transmission is not a risk reusable SADs should be sterilised. This advice is based on evidence that microscopic traces of tissue can remain on surgical instruments after washing, autoclaving, and disinfection and that routine methods for cleaning SADs do not completely remove protein deposits (57–59). Protein cross-contamination occurs during batch cleaning and autoclaving (60) and furthermore, sterilisation methods do not denature prions (61). Following release of this guidance, there was a proliferation of single-use surgical and anesthetic equipment accompanied by concerns regarding their quality and efficacy (56). After increased morbidity was shown when using disposable surgical instruments, the DoH reversed its decision with regard to surgical equipment, but kept the guideline in place for all anesthetic equipment (62), which remains to this day. While increased morbidity with respect to surgery is relatively easy to demonstrate with easy to audit outcomes: blood loss, rates of return to theater, and incidence of primary and secondary hemorrhage, no such easy outcome parameters exist in the clinical evaluation of airway equipment. So, despite one of several reviews demonstrating that single-use laryngoscope blades severely underperformed compared to their reusable counterparts (63), the lack of quantifiable harm to patients reduces the impact of such reviews. It is reasonable to argue that anesthetists should balance the risk of transmitting Variant Creutzfeldt-Jakob disease (vCJD) against the use of inferior airway equipment (64). Thus far, there are no proven cases of vCJD transmission via airway equipment, and this is perhaps not
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surprising given that analysis of over 63 000 tonsil specimens found no presence of the pathogenic form of the prion protein (65). Data from The National CJD Research and Surveillance Unit, which report deaths attributable to vCJD, report only one case since January 2012 compared with a peak incidence of 28 in 2000 and from a projection of a year on year increase in reported cases the incidence has fallen (66). Some scepticism among anesthetists regarding the transmission of vCJD via reusable equipment is revealed in the results of a survey of UK practice looking at compliance with the DoH guideline on the use of disposable airway equipment for tonsillectomy. Fifty five percent of responders disagreed with the guideline, and full compliance was only seen in 16% of responders (67). With a lack of evidence to suggest that reusable airway equipment that is suitably decontaminated poses a risk to patients, and in light of the absence of pathogenic prion protein in tonsil specimens where does this leave existing guidance with respect to the use of single-use airway devices in adenoid and tonsil surgery? And if the patient safety argument holds for this subset of patients, then the driver for single-use equipment across all other procedures is weakened, the argument distilling to one of cost. It is difficult to directly compare the cost of reusable devices with single-use alternatives. With the increasing availability of a plethora of single-use versions, the unit cost is a fraction of that of the reusable classic laryngeal mask airway. While the manufacturer recommendations indicate that the classic laryngeal mask airway may be reused up to 40 times, tests indicate this lifespan could safely be increased to 60 uses before failing the recommended preuse tests (68). The total cost of the classic laryngeal mask airway then has to take into account cost of sterilisation per use. While the up-front cost of a plastic SAD is small, the hidden cost lies in the consequent disposal. An estimated 500 million SADs have been used worldwide up to 2006 (69), antedating a surge in single-use SAD manufacture that we have seen in recent years. Approximately 85 000 tons of PVC medical devices are used in Europe annually and given that recycling is not an option the default method of disposal is incineration. A comparison of the environmental impact of life cycles of reusable and disposable SADs strongly favors the use of reusable devices (70). Indeed, it can be argued that the continued use of reusable products is integral to a practice of ‘Sustainable Anesthesia’ (71). Given the superiority in performance and smaller environmental cost of reusable SADs, these remain a more cost-effective option than single-use SADs.
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Conclusions The modern trend for disposable airway devices is as much driven by aesthetics and market demands for single patient, single-use equipment as evidence that reusable airway devices carry any more than a tiny risk of disease transfer. However, with demands for patient safety overtly paramount, this trend will not be reversed despite the performance advantages and lower wider environmental cost of, in particular, reusable SADs. Here, the NHS has chosen arguably the lesser cost-effective option. The one disposable success story, that of the cuffed tracheal tube has had limited take-up, ironically due to cost despite it’s clinical effectiveness. Airway viewing devices represent the future of laryngoscopy but at considerable up-front monetary cost and the potential longer-term cost to our core skill, use of
the conventional laryngoscope. This threat to one part of our skill set is amplified by the overwhelming use of SADs in clinical practice and the loss of the art of facemask anesthesia. These twin threats represent the true costs of this advance in airway technology. Perhaps the final arbiter of cost-effectiveness will be the quality and safety of patient care. Time will be our judge. Acknowledgments No ethical approval was needed in production of this manuscript. This research was carried out without funding. Conflict of interest The authors declare no conflict of interest.
References 1 Brain AI. The laryngeal mask - a new concept in airway management. Br J Anaesth 1983; 55: 801–805. 2 Miller DM. A proposed classification and scoring system for supraglottic sealing airways: a brief review. Anesth Analg 2004; 99: 1553–1559. 3 Mason DG, Bingham RM. The laryngeal mask airway in children. Anaesthesia 1990; 45: 760–763. 4 Lopez-Gil M, Brimacombe J, Alvarez M. Safety and efficacy of the laryngeal mask airway. Anaesthesia 1996; 51: 969–972. 5 Naguib ML, Streetman DS, Clifton S et al. Use of laryngeal mask airway in flexible bronchoscopy in infants and children. Pediatr Pulmonol 2005; 39: 56–63. 6 George JM, Sanders GM. The reinforced laryngeal mask in paediatric outpatient dental surgery. Anaesthesia 1999; 54: 546–551. 7 Flynn P, Ahmed FB, Mitchell V et al. A randomised comparison of the single use LMA Flexible with the reusable LMA Flexible in paediatric dental day-case patients. Anaesthesia 2007; 62: 1281–1284. 8 Bradley AED, White MC, Engelhardt T et al. Current UK practice of pediatric supraglottic airway devices - a survey of members of the Association of Paediatric Anaesthetists of Great Britain and Ireland. Pediatr Anesth 2013; 23: 1006–1009. 9 The Royal College of Anaesthetists, The Difficult Airway Society. 4th National Audit Project: Major complications of airway management in the United Kingdom. 2011. Available at: http://www.rcoa.ac.uk/system/ files/CSQ-NAP4-Full.pdf. Accessed 23 September, 2014. 10 White MC, Cook TM, Stoddart PA. A critique of elective pediatric supraglottic airway © 2014 John Wiley & Sons Ltd Pediatric Anesthesia 25 (2015) 20–26
11
12
13
14
15
16
17
18
19
devices. Pediatr Anesth 2009; 19(Suppl. 1): 55–65. Shimbori H, Ono K, Miwa T et al. Comparison of the LMA-ProSeal and LMA-Classic in children. Br J Anaesth 2004; 93: 528–531. Goldmann K, Roettger C, Wulf H. The size 1 1/2 ProSeal laryngeal mask airway in infants: a randomized, crossover investigation with the Classic laryngeal mask airway. Anesth Analg 2006; 102: 405–410. Goldmann K, Jakob C. Size 2 ProSeal laryngeal mask airway: a randomized, crossover investigation with the standard laryngeal mask airway in paediatric patients. Br J Anaesth 2005; 94: 385–389. Goldmann K, Jakob C. A randomized crossover comparison of the size 2 1/2 laryngeal mask airway ProSeal versus laryngeal mask airway-Classic in pediatric patients. Anesth Analg 2005; 100: 1605–1610. Lopez-Gil M, Brimacombe J, Garcia G. A randomized non-crossover study comparing the ProSeal and Classic laryngeal mask airway in anaesthetized children. Br J Anaesth 2005; 95: 827–830. Lardner DRR, Cox RG, Ewen A et al. Comparison of laryngeal mask airway (LMA)Proseal and the LMA-Classic in ventilated children receiving neuromuscular blockade. Can J Anaesth 2008; 55: 29–35. Kelly F, Sale S, Bayley G et al. A cohort evaluation of the pediatric ProSeal laryngeal mask airway in 100 children. Pediatr Anesth 2008; 18: 947–951. Lee J-R, Kim M-S, Kim J-T et al. A randomised trial comparing the i-gelTM with the LMA ClassicTM in children. Anaesthesia 2012; 67: 606–611. Beylacq L, Bordes M, Semjen F et al. The Igel, a single-use supraglottic airway device
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23
24
25
26
27
with a non-inflatable cuff and an esophageal vent: an observational study in children. Acta Anaesthesiol Scand 2009; 53: 376–379. Theiler LG, Kleine-Brueggeney M, Luepold B et al. Performance of the pediatric-sized i-gel compared with the Ambu AuraOnce laryngeal mask in anesthetized and ventilated children. Anesthesiology 2011; 115: 102–110. Beringer RM, Kelly F, Cook TM et al. A cohort evaluation of the paediatric i-gelTM airway during anaesthesia in 120 children. Anaesthesia 2011; 66: 1121–1126. Hughes C, Place K, Berg S et al. A clinical evaluation of the i-gel supraglottic airway device in children. Pediatr Anesth 2012; 22: 765–771. Jagannathan N, Sohn LE, Sawardekar A et al. A randomised trial comparing the laryngeal mask airway SupremeTM with the laryngeal mask airway UniqueTM in children. Anaesthesia 2012; 67: 139–144. Jagannathan N, Sohn LE, Sawardekar A et al. A randomised comparison of the selfpressurised air-QTM intubating laryngeal airway with the LMA UniqueTM in children. Anaesthesia 2012; 67: 973–979. Gaitini L, Carmi N, Yanovski B et al. Comparison of the CobraPLA (Cobra Perilaryngeal Airway) and the Laryngeal Mask Airway Unique in children under pressure controlled ventilation. Pediatr Anesth 2008; 18: 313–319. Szmuk P, Ghelber O, Matuszczak M et al. A prospective, randomized comparison of cobra perilaryngeal airway and laryngeal mask airway unique in pediatric patients. Anesth Analg 2008; 107: 1523–1530. Jagannathan N, Sequera-Ramos L, Sohn L et al. Elective use of supraglottic airway devices for primary airway management in
25
S.J. Slinn et al.
Are new airway devices cost-effective?
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
26
children with difficult airways. Br J Anaesth 2014; 112: 742–748. Walker RW. The laryngeal mask airway in the difficult paediatric airway: an assessment of positioning and use in fibreoptic intubation. Paediatr Anaesth 2000; 10: 53–58. Walker RWM, Allen DL, Rothera MR. A fibreoptic intubation technique for children with mucopolysaccharidoses using the laryngeal mask airway. Paediatr Anaesth 1997; 7: 421–426. Weiss M, Engelhardt T. Proposal for the management of the unexpected difficult pediatric airway. Pediatr Anesth 2010; 20: 454– 464. APAGBI. Paediatric Difficult Airway Guidelines. 2012. Available at: http://www.apagbi. org.uk/publications/apa-guidelines. Accessed 31 July, 2014. Baker PA, Brunette KEJ, Byrnes CA et al. A prospective randomized trial comparing supraglottic airways for flexible bronchoscopy in children. Pediatr Anesth 2010; 20: 831–838. Wong JGL, Heaney M, Chambers NA et al. Impact of laryngeal mask airway cuff pressures on the incidence of sore throat in children. Pediatr Anesth 2009; 19: 464–469. Sinha A, Sharma B, Sood J. ProSeal as an alternative to endotracheal intubation in pediatric laparoscopy. Pediatr Anesth 2007; 17: 327–332. Wilson IG. The laryngeal mask airway in paediatric practice. Br J Anaesth 1993; 70: 124–125. Russell D. Trainee anaesthetists and the laryngeal mask airway. Anaesthesia 1991; 46: 701. Harnett M, Kinirons B, Heffernan A et al. Airway complications in infants: comparison of laryngeal mask airway and the facemaskoral airway. Can J Anaesth 2000; 47: 315–318. Rechner JA, Loach VJ, Ali MT et al. A comparison of the laryngeal mask airway with facemask and oropharyngeal airway for manual ventilation by critical care nurses in children. Anaesthesia 2007; 62: 790–795. Ong M, Chambers NA, Hullet B et al. Laryngeal mask airway and tracheal tube cuff pressures in children: are clinical endpoints valuable for guiding inflation? Anaesthesia 2008; 63: 738–744. Khine HH, Corddry DH, Kettrick RG et al. Comparison of cuffed and uncuffed endotracheal tubes in young children during general anaesthesia. Anesthesiology 1997; 86: 627–631. Weber T, Salvi N, Orliaguet G et al. ProCon Debate: cuffed vs non-cuffed endotracheal tubes for pediatric anesthesia. Pediatr Anesth 2009; 19(Suppl. 1): 46–54. Litman RS, Weissend EE, Shibata D et al. Developmental changes of laryngeal dimensions in unparalyzed, sedated children. Anesthesiology 2003; 98: 41–45.
43 Weiss M, Dullenkopf A, Fischer JE et al. Prospective randomized controlled multicentre trial of cuffed or uncuffed endotracheal tubes in small children. Br J Anaesth 2009; 103: 867–873. 44 Holm-Knudsen R. The difficult pediatric airway-a review of new devices for indirect laryngoscopy in children younger than two years of age. Pediatr Anesth 2011; 21: 98– 103. 45 Kim J, Na H, Bae J et al. GlideScope videolaryngoscope: a randomized clinical trial in 203 paediatric patients. Br J Anaesth 2008; 101: 531–534. 46 Redel A, Karademir F, Schlitterlau A et al. Validation of the glidescope videolaryngoscope in pediatric patients. Pediatr Anesth 2009; 19: 667–671. 47 Fiadjoe JE, Gurnaney H, Dalesio N et al. A prospective randomized equivalence trial of the GlideScope Cobaltâ videolaryngoscope to traditional direct laryngoscopy in neonates and infants. Anesthesiology 2012; 116: 622– 628. 48 Fiadjoe JE, Stricker PA, Hackell RS et al. The efficacy of the Storz Miller 1 videolaryngoscope in a simulated infant difficult intubation. Anesth Analg 2009; 108: 1783–1786. 49 Vlatten A, Aucoin S, Litz S et al. A comparison of the STORZ videolaryngoscope and standard direct laryngoscopy for intubation in the Pediatric airway - a randomized clinical trial. Pediatr Anesth 2009; 19: 1102–1107. 50 Ali QE, Amir SH, Firdaus U et al. A comparative study of the efficacy of Pediatric Airtraq with conventional laryngoscope in children. Minerva Anestesiol 2013; 79: 1366– 1370. 51 Riad W, Moussa A, Wong DT. AirtraqTM versus Macintoch laryngoscope in intubation performance in the pediatric population. Saudi J Anaesth 2012; 6: 332–335. 52 Riveros R, Sung W, Sessler DI et al. Comparison of the Truview PCDTM and the GlideScopeâ videolaryngoscopes with direct laryngoscopy in pediatric patients: a randomized trial. Can J Anaesth 2013; 60: 450–457. 53 Weiss M, Schwarz U, Diller CM et al. Teaching and supervising tracheal intubation in paediatric patients using videolaryngoscopy. Paediatr Anaesth 2001; 11: 343–348. 54 Sun Y, Lu Y, Huang Y et al. Pediatric videolaryngoscope versus direct laryngoscope: a meta-analysis of randomized controlled trials. Pediatr Anesth 2014; 24: 1056– 1065. 55 Department of Health. £200 Million for NHS Equipment to Protect Patients Against Possible Variant CJD Risk. London: Department of Health, 2001. (Press release 2001/ 0012). 56 AAGBI. Infection control in anaesthesia. Anaesthesia 2008; 63: 1027–1036.
57 Coetzee GJ. Eliminating protein from reusable laryngeal mask. Anaesthesia 2003; 58: 346–352. 58 Clery G, Brimacombe J, Stone T et al. Routine cleaning and autoclaving does not remove protein deposits from reusable laryngeal mask devices. Anesth Analg 2003; 97: 1189–1191. 59 Miller DM, Youkhana I, Karunaratne WU et al. Presence of protein deposits on “cleaned” re-usable anaesthetic equipment. Anaesthesia 2001; 56: 1069–1072. 60 Richards E, Brimacombe J, Laupau W et al. Protein cross-contamination during batch cleaning and autoclaving of the ProSeal laryngeal mask airway. Anaesthesia 2006; 61: 431–433. 61 Taylor DM. Inactivation of prions by physical and chemical means. J Hosp Infect 1999; 43(Suppl.): S69–S76. 62 Department of Health. Re-Introduction of Re-Usable Instruments for Tonsil Surgery. London: Department of Health, 2001. Available at: http://webarchive.nationalarchives. gov.uk/+/www.dh.gov.uk/en/Publicationsandstatistics/Pressreleases/DH_4011629. Accessed 20 August, 2014. 63 Twigg SJ, McCormick B, Cook TM. Randomized evaluation of the performance of single-use laryngoscopes in simulated easy and difficult intubation. Br J Anaesth 2003; 90: 8–13. 64 Blunt MC, Burchett KR. Variant Creutzfeldt-Jakob disease and disposable anaesthetic equipment - balancing the risks. Br J Anaesth 2003; 90: 1–3. 65 Clewley JP, Kelly CM, Andrews N et al. Prevalence of disease related prion protein in anonymous tonsil specimens in Britain: cross sectional opportunistic survey. Br Med J 2009; 338: 1442–1448. 66 The National CJD Research and Surveillance Unit. Creutzfeldt-Jakob Disease in the UK. 2014. Available at: http://www.cjd.ed.ac.uk/. 67 Clarke MB, Forster P, Cook TM. Airway management for tonsillectomy: a national survey of UK practice. Br J Anaesth 2007; 99: 425–428. 68 Berry AM, Brimacombe JR, McManus KF et al. An evaluation of the factors influencing selection of the optimal size of laryngeal mask airway in normal adults. Anaesthesia 1998; 53: 565–570. 69 Cook TM. The classic laryngeal mask airway: a tried and tested airway. What now? Br J Anaesth 2006; 96: 149–152. 70 Eckelman M, Mosher M, Gonzalez A et al. Comparative life cycle assessment of disposable and reusable laryngeal mask airways. Anesth Analg 2012; 114: 1067–1072. 71 Ryan S, Sherman J. Sustainable anesthesia. Anesth Analg 2012; 114: 921–923.
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