136
| Correspondence
off-pump coronary artery bypass surgery. J Anesth 2015; 29: 416–20 16. Jones TW, Houghton D, Cassidy S, MacGowan GA, Trenell MI, Jakovljevic DG. Bioreactance is a reliable method for estimating cardiac output at rest and during exercise. Br J Anaesth 2015; 115: 386–91 17. Jakovljevic DG, Moore S, Hallsworth K, Fattakhova G, Thoma C, Trenell MI. Comparison of cardiac output
determined by bioimpedance and bioreactance methods at rest and during exercise. J Clin Monit Comput 2012; 26: 63–8 18. Jakovljevic DG, Papakonstantinou L, Blamire AM, et al. Effect of physical activity on age-related changes in cardiac function and performance in women. Circ Cardiovasc Imag 2015; 8. pii: e002086 19. Jakovljevic DG, Trenell MI, MacGowan GA. Bioimpedance and bioreactance methods for monitoring cardiac output. Best Pract Res Clin Anaesth 2014; 28: 381–94 doi:10.1093/bja/aew164
A further plea for a unified classification of supraglottic (extraglottic) airway devices T. M. Cook* Bath, UK *E-mail: [email protected]
Editor—I read Dr Miller’s letter1 in response to mine2 with interest. My letter was in no way personal to him or his publications. Dr Miller has made important contributions to this area of practice in both his inventions and his academic contributions. I believe it is important to correct some factual points, in order that the reader is not misled or confused. First, my concern is for any use (academic, commercial, or otherwise) of the term ‘thirdgeneration supraglottic airway device (SAD)’ when the term is illogical based on the existing definition of first/second-generation SAD. For clarity, the definition of ‘second-generation SAD’ always applied to SADs; first, as ‘second generation devices incorporate specific design features to improve safety by protecting against regurgitation and aspiration’3 and then, as ‘SADs that have been designed for safety and which have design features to reduce the risk of aspiration’.4 The definition applies to all SADs and not only to laryngeal mask airways. I agree with Dr Miller on two important points. First, the classification has limitations. In particular, the use of the term ‘generations’ is imprecise in terms of ‘chronology’; the Combitube—a SAD which is now of largely historical interest—is clearly a second-generation device. The use of the term ‘generation’ perhaps apes its use in a number of other fields, such as telephony and communications, where a higher generation implies technical improvements. Despite this, first/second-generation classification has come into common use in the UK (e.g. in the Difficult Airway Society guidelines) and internationally; perhaps that is its greatest strength. Previous, more complex classifications based on anatomical features have not found traction in this way.5 6 I also agree that a new classification may be needed. Dr Miller’s proposed7 and previous classification5 both emphasize the location of the seal as of prime importance. Unfortunately, the latest classification again uses the term ‘generation’ (but with a new definition) and includes a whole section (generation) for a single device whose current iteration has no performance data published on it. This classification has some merit but is perhaps of greatest value for SAD inventors and designers. Conversely, the terms first and second generation—appropriately used—refer to performance features, most particularly safety, which are of direct practical importance in selecting devices. We have numerous effective SADs, which often seal in different places; what we
must strive for is the safest.8 It is worth remembering that in NAP4 (the 4th National Audit Project), aspiration was the commonest cause of anaesthesia-related death and brain damage.9 Half of these events occurred during the use of a SAD, 90% of which were first-generation SADs. One line from Dr Miller’s letter perhaps illustrates our difference of approach. Dr Miller writes, ‘improving the laryngeal mask airway to minimize the risk of aspiration is an important provision of an additional feature but not a step change in the concept of EADs’. I would revise this to ‘improving a SAD to minimize the risk of aspiration is the most important step change possible in the development of such a device’. In summary, it seems to me logical and practical to embrace the current widely used terminology—warts and all—until such time as a better ( practical) classification is agreed on. I am happy to work with any party to try and achieve this and have previously suggested the need for such a collaboration to a number of international airway experts. The offer remains open.
Declaration of interest I am an associate editor of the BJA. My department has received numerous airway devices at cost or for free, for evaluation or research.
References 1. Miller DM. Third generation supraglottic airways: is a new classification needed? Br J Anaesth 2015; 115: 634–5 2. Cook TM. Third generation supraglottic airway devices: an undefined concept and misused term. Time for an updated classification of supraglottic airway devices. Br J Anaesth 2015; 115: 633–4 3. White MC, Cook TM, Stoddard PA. A critique of elective pediatric supraglottic airway devices. Pediatr Anesth 2009; 19(Suppl. 1): 55–65 4. Cook TM, Howes B. Recent developments in efficacy and safety of supraglottic airway devices. Contin Educ Anaesth Crit Care Pain 2011; 11: 56–61
Correspondence
5. Brimacombe J. A proposed classification system for extraglottic airway devices. Anesthesiology 2004; 101: 559 6. Miller DM. A proposed classification and scoring system for supraglottic sealing airways: a brief review. Anesth Analg 2004; 99: 1553–9 7. Michálek P, Miller DM. Airway management evolution – in a search for an ideal extraglottic airway device. Prague Med Rep 2014; 115: 87–103
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8. Cook TM, Kelly FE. Time to abandon the ‘vintage’ laryngeal mask airway and adopt second-generation supraglottic airway devices as first choice. Br J Anaesth 2015; 115: 497–9 9. Cook TM, Woodall N, Frerk C. Major complications of airway management in the UK: results of the 4th National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part 1 Anaesthesia. Br J Anaesth 2011; 106: 617–31 doi:10.1093/bja/aew165
A new view of safety: Safety 2 J. K. Chan* Northern Health, Epping, Victoria, Australia *E-mail: [email protected]
Editor—The definition of safety in health care has indeed changed over time, as indicated by Ball and Frerk1 in their editorial. The Australian Commission on Safety and Quality in Health Care (ACSQHC) has three broad principles that it emphasizes in order to build on safety and quality; these are that care is consumer centred, driven by information, and organized for safety. There are also the National Safety and Quality Health Service standards that have been developed to provide a consistent level of care that consumers can expect from health organizations.2 All of these changes are consistent with the notion of Safety 2, wherewe are changing from a reactive to a proactive stance on safety. The airline industry has also responded appropriately in light of recent aviation disasters by also changing their approach to aviation safety. The aviation industry is the industry leader in implementing safety initiatives, and there is much to be gained from their practices. They are trialling the Identifying Needed Defences in the Civil Aviation Transport Environment (INDICATE), which is an airline safety management tool that encourages regular passenger transport operators to evaluate critically and improve the strength of their safety system. This type of feedback is important because it enables early recognition of potential deficiencies before they even become problems.3 Similar initiatives in health care involve obtaining feedback from consumers and carers about their health-care experience. Anaesthesia is an evolving specialty, and anaesthetists are no longer restricted within the confines of the theatre environment. The current work of a typical anaesthetist would also involve ‘offthe-floor’ work, doing pain rounds as part of the Acute Pain Service and perioperative medicine, where patients are continually optimized and cared for before and after surgery. This increasingly complex workload puts increasing demand on the available defences against breaches in quality and safety. As the authors correctly point out, there may no longer be an easily identifiable solution to an error that has been generated by the complex interactions that have produced it.1 The authors point out with Safety 2 that studying success is the core focus. Resilience engineering is a key concept that was introduced in the article, where although resilient systems can and do fail, they demonstrate a repertoire of behaviours, including the following: qualitative shifts in performance in response to varying demands; purposeful, meaningful responses reflected by
goal trade-offs; and a tenacity of efforts to respond effectively even when confronted by escalating demands or existential threats. Hollnagel identifies four related aspects of resilience: monitoring or exploring the system’s function and performance; responding or reacting to events or conditions; anticipating or foreseeing future events and conditions; and learning or reorganizing system knowledge.4 Safety and quality go hand in hand in the advancement of health care. A quality control measure in the manufacture of equipment, cumulative sum (CUSUM), is also of benefit, especially in procedural training. The CUSUM allows detection of deviations in the norm rather than assessing each failure.5 This is an underused tool, which will allow early recognition of deteriorating performance, rather than waiting for disaster to strike first. Anaesthesia is one of the safest medical specialties there is, and in order to make it even safer we need to examine the pathways leading to success and adopt early warning and surveillance mechanisms to avert disaster.
Declaration of interest None declared.
References 1. Ball DR, Frerk C. A new view of safety: Safety 2. Br J Anaesth 2015; 115: 645–7 2. Australian Commission on Safety and Quality in Health Care. Putting the framework into action: getting started. 2011. Available from http://www.safetyandquality.gov.au/wp-content/ uploads/2011/01/ASQFHC-Guide-Healthcare-team.pdf (accessed 23 August 2015) 3. Australian Transport Safety Bureau. INDICATE. 1999. Available from https://www.atsb.gov.au/media/30788/sir199906_002.pdf (accessed 23 August 2015) 4. Fairbanks RJ, Wears RL, Woods DD, Hollnagel E, Plsek P, Cook RI. Resilience and resilience engineering in health care. Jt Comm J Qual Patient Saf 2014; 40: 376–83 5. Norris A, McCahon R. Cumulative sum (CUSUM) assessment and medical education: a square peg in a round hole. Anaesthesia 2011; 66: 250–4 doi:10.1093/bja/aew166
| Correspondence
off-pump coronary artery bypass surgery. J Anesth 2015; 29: 416–20 16. Jones TW, Houghton D, Cassidy S, MacGowan GA, Trenell MI, Jakovljevic DG. Bioreactance is a reliable method for estimating cardiac output at rest and during exercise. Br J Anaesth 2015; 115: 386–91 17. Jakovljevic DG, Moore S, Hallsworth K, Fattakhova G, Thoma C, Trenell MI. Comparison of cardiac output
determined by bioimpedance and bioreactance methods at rest and during exercise. J Clin Monit Comput 2012; 26: 63–8 18. Jakovljevic DG, Papakonstantinou L, Blamire AM, et al. Effect of physical activity on age-related changes in cardiac function and performance in women. Circ Cardiovasc Imag 2015; 8. pii: e002086 19. Jakovljevic DG, Trenell MI, MacGowan GA. Bioimpedance and bioreactance methods for monitoring cardiac output. Best Pract Res Clin Anaesth 2014; 28: 381–94 doi:10.1093/bja/aew164
A further plea for a unified classification of supraglottic (extraglottic) airway devices T. M. Cook* Bath, UK *E-mail: [email protected]
Editor—I read Dr Miller’s letter1 in response to mine2 with interest. My letter was in no way personal to him or his publications. Dr Miller has made important contributions to this area of practice in both his inventions and his academic contributions. I believe it is important to correct some factual points, in order that the reader is not misled or confused. First, my concern is for any use (academic, commercial, or otherwise) of the term ‘thirdgeneration supraglottic airway device (SAD)’ when the term is illogical based on the existing definition of first/second-generation SAD. For clarity, the definition of ‘second-generation SAD’ always applied to SADs; first, as ‘second generation devices incorporate specific design features to improve safety by protecting against regurgitation and aspiration’3 and then, as ‘SADs that have been designed for safety and which have design features to reduce the risk of aspiration’.4 The definition applies to all SADs and not only to laryngeal mask airways. I agree with Dr Miller on two important points. First, the classification has limitations. In particular, the use of the term ‘generations’ is imprecise in terms of ‘chronology’; the Combitube—a SAD which is now of largely historical interest—is clearly a second-generation device. The use of the term ‘generation’ perhaps apes its use in a number of other fields, such as telephony and communications, where a higher generation implies technical improvements. Despite this, first/second-generation classification has come into common use in the UK (e.g. in the Difficult Airway Society guidelines) and internationally; perhaps that is its greatest strength. Previous, more complex classifications based on anatomical features have not found traction in this way.5 6 I also agree that a new classification may be needed. Dr Miller’s proposed7 and previous classification5 both emphasize the location of the seal as of prime importance. Unfortunately, the latest classification again uses the term ‘generation’ (but with a new definition) and includes a whole section (generation) for a single device whose current iteration has no performance data published on it. This classification has some merit but is perhaps of greatest value for SAD inventors and designers. Conversely, the terms first and second generation—appropriately used—refer to performance features, most particularly safety, which are of direct practical importance in selecting devices. We have numerous effective SADs, which often seal in different places; what we
must strive for is the safest.8 It is worth remembering that in NAP4 (the 4th National Audit Project), aspiration was the commonest cause of anaesthesia-related death and brain damage.9 Half of these events occurred during the use of a SAD, 90% of which were first-generation SADs. One line from Dr Miller’s letter perhaps illustrates our difference of approach. Dr Miller writes, ‘improving the laryngeal mask airway to minimize the risk of aspiration is an important provision of an additional feature but not a step change in the concept of EADs’. I would revise this to ‘improving a SAD to minimize the risk of aspiration is the most important step change possible in the development of such a device’. In summary, it seems to me logical and practical to embrace the current widely used terminology—warts and all—until such time as a better ( practical) classification is agreed on. I am happy to work with any party to try and achieve this and have previously suggested the need for such a collaboration to a number of international airway experts. The offer remains open.
Declaration of interest I am an associate editor of the BJA. My department has received numerous airway devices at cost or for free, for evaluation or research.
References 1. Miller DM. Third generation supraglottic airways: is a new classification needed? Br J Anaesth 2015; 115: 634–5 2. Cook TM. Third generation supraglottic airway devices: an undefined concept and misused term. Time for an updated classification of supraglottic airway devices. Br J Anaesth 2015; 115: 633–4 3. White MC, Cook TM, Stoddard PA. A critique of elective pediatric supraglottic airway devices. Pediatr Anesth 2009; 19(Suppl. 1): 55–65 4. Cook TM, Howes B. Recent developments in efficacy and safety of supraglottic airway devices. Contin Educ Anaesth Crit Care Pain 2011; 11: 56–61
Correspondence
5. Brimacombe J. A proposed classification system for extraglottic airway devices. Anesthesiology 2004; 101: 559 6. Miller DM. A proposed classification and scoring system for supraglottic sealing airways: a brief review. Anesth Analg 2004; 99: 1553–9 7. Michálek P, Miller DM. Airway management evolution – in a search for an ideal extraglottic airway device. Prague Med Rep 2014; 115: 87–103
| 137
8. Cook TM, Kelly FE. Time to abandon the ‘vintage’ laryngeal mask airway and adopt second-generation supraglottic airway devices as first choice. Br J Anaesth 2015; 115: 497–9 9. Cook TM, Woodall N, Frerk C. Major complications of airway management in the UK: results of the 4th National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part 1 Anaesthesia. Br J Anaesth 2011; 106: 617–31 doi:10.1093/bja/aew165
A new view of safety: Safety 2 J. K. Chan* Northern Health, Epping, Victoria, Australia *E-mail: [email protected]
Editor—The definition of safety in health care has indeed changed over time, as indicated by Ball and Frerk1 in their editorial. The Australian Commission on Safety and Quality in Health Care (ACSQHC) has three broad principles that it emphasizes in order to build on safety and quality; these are that care is consumer centred, driven by information, and organized for safety. There are also the National Safety and Quality Health Service standards that have been developed to provide a consistent level of care that consumers can expect from health organizations.2 All of these changes are consistent with the notion of Safety 2, wherewe are changing from a reactive to a proactive stance on safety. The airline industry has also responded appropriately in light of recent aviation disasters by also changing their approach to aviation safety. The aviation industry is the industry leader in implementing safety initiatives, and there is much to be gained from their practices. They are trialling the Identifying Needed Defences in the Civil Aviation Transport Environment (INDICATE), which is an airline safety management tool that encourages regular passenger transport operators to evaluate critically and improve the strength of their safety system. This type of feedback is important because it enables early recognition of potential deficiencies before they even become problems.3 Similar initiatives in health care involve obtaining feedback from consumers and carers about their health-care experience. Anaesthesia is an evolving specialty, and anaesthetists are no longer restricted within the confines of the theatre environment. The current work of a typical anaesthetist would also involve ‘offthe-floor’ work, doing pain rounds as part of the Acute Pain Service and perioperative medicine, where patients are continually optimized and cared for before and after surgery. This increasingly complex workload puts increasing demand on the available defences against breaches in quality and safety. As the authors correctly point out, there may no longer be an easily identifiable solution to an error that has been generated by the complex interactions that have produced it.1 The authors point out with Safety 2 that studying success is the core focus. Resilience engineering is a key concept that was introduced in the article, where although resilient systems can and do fail, they demonstrate a repertoire of behaviours, including the following: qualitative shifts in performance in response to varying demands; purposeful, meaningful responses reflected by
goal trade-offs; and a tenacity of efforts to respond effectively even when confronted by escalating demands or existential threats. Hollnagel identifies four related aspects of resilience: monitoring or exploring the system’s function and performance; responding or reacting to events or conditions; anticipating or foreseeing future events and conditions; and learning or reorganizing system knowledge.4 Safety and quality go hand in hand in the advancement of health care. A quality control measure in the manufacture of equipment, cumulative sum (CUSUM), is also of benefit, especially in procedural training. The CUSUM allows detection of deviations in the norm rather than assessing each failure.5 This is an underused tool, which will allow early recognition of deteriorating performance, rather than waiting for disaster to strike first. Anaesthesia is one of the safest medical specialties there is, and in order to make it even safer we need to examine the pathways leading to success and adopt early warning and surveillance mechanisms to avert disaster.
Declaration of interest None declared.
References 1. Ball DR, Frerk C. A new view of safety: Safety 2. Br J Anaesth 2015; 115: 645–7 2. Australian Commission on Safety and Quality in Health Care. Putting the framework into action: getting started. 2011. Available from http://www.safetyandquality.gov.au/wp-content/ uploads/2011/01/ASQFHC-Guide-Healthcare-team.pdf (accessed 23 August 2015) 3. Australian Transport Safety Bureau. INDICATE. 1999. Available from https://www.atsb.gov.au/media/30788/sir199906_002.pdf (accessed 23 August 2015) 4. Fairbanks RJ, Wears RL, Woods DD, Hollnagel E, Plsek P, Cook RI. Resilience and resilience engineering in health care. Jt Comm J Qual Patient Saf 2014; 40: 376–83 5. Norris A, McCahon R. Cumulative sum (CUSUM) assessment and medical education: a square peg in a round hole. Anaesthesia 2011; 66: 250–4 doi:10.1093/bja/aew166
