Anaesthesia 2015, 70, 344–359

doi:10.1111/anae.12917

Review Article Cranial nerve injuries with supraglottic airway devices: a systematic review of published case reports and series V. Thiruvenkatarajan,1,2 R. M. Van Wijk3,4 and A. Rajbhoj1,2 1 Staff Specialist Anaesthetist, 3 Head, Department of Anaesthesia, The Queen Elizabeth Hospital, Woodville, South Australia, Australia 2 Clinical Senior Lecturer, 4 Associate Professor, Discipline of Acute Care Medicine, The University of Adelaide, Adelaide, South Australia, Australia

Summary Cranial nerve injuries are unusual complications of supraglottic airway use. Branches of the trigeminal, glossopharyngeal, vagus and the hypoglossal nerve may all be injured. We performed a systematic review of published case reports and case series of cranial nerve injury from the use of supraglottic airway devices. Lingual nerve injury was the most commonly reported (22 patients), followed by recurrent laryngeal (17 patients), hypoglossal (11 patients), glossopharyngeal (three patients), inferior alveolar (two patients) and infra-orbital (one patient). Injury is generally thought to result from pressure neuropraxia. Contributing factors may include: an inappropriate size or misplacement of the device; patient position; overinflation of the device cuff; and poor technique. Injuries other than to the recurrent laryngeal nerve are usually mild and self-limiting. Understanding the diverse presentation of cranial nerve injuries helps to distinguish them from other complications and assists in their management. .................................................................................................................................................................

Correspondence to: V. Thiruvenkatarajan Email: [email protected] Accepted: 22 September 2014 Presented at the Australian and New Zealand College of Anaesthetists’ Annual Scientific Meeting, Singapore, May 2014.

Introduction The classic laryngeal mask airway (cLMA, LMA North America, San Diego, CA, USA) was invented by Dr Archie Brain in 1981 and introduced into clinical practice in 1988 [1, 2]. Since that time, other airway devices that do not pass through the larynx have been invented, and these and the original LMA are referred to as supraglottic airway devices. They are widely used in day-to-day practice, being used in roughly 50% of all general anaesthetic procedures [2]. The morbidity associated with the use of supraglottic airway devices is largely defined by minor pharyngolaryngeal complications such as: sore throat (17– 344

42% of patients) [3]; soft tissue abrasion (16–32%) [4]; hoarseness and dysphagia. Cranial nerve injury after the use of a supraglottic airway device is an unusual but more serious complication. So far, injuries of lingual, inferior alveolar, infra-orbital, glossopharyngeal, recurrent laryngeal and hypoglossal nerves have been reported. The true incidence of these injuries is not known; we suspect many are not reported. We have conducted a systematic review of all published case reports and case series of cranial nerve injury following the use of supraglottic airway devices. The aim of this review is to analyse and summarise the features of cranial nerve injuries associated with supraglottic airway © 2014 The Association of Anaesthetists of Great Britain and Ireland

Thiruvenkatarajan et al. | Cranial nerve injuries with supraglottic airway devices

devices, with particular emphasis on contributing factors.

Methods We searched PubMed and Embase for material published up to April 31, 2014, and identified case reports and case series mentioning cranial nerve injuries associated with supraglottic airway devices (details of the search strategy are presented in the Appendix). The search was not limited to a particular start date and we did not impose a restriction on language of publication. The bibliographies of the identified publications were hand-searched for additional reports. We included reports of both adults and children, as there seems to be no clear evidence that the mechanisms of nerve injury differ between these two groups. To be included, the reports had to describe and confirm the clinical evidence of cranial nerve injury in association with the use of any type of supraglottic airway device. Two authors working independently extracted the following data: age, sex and weight of the patient; size and type of device inserted; use of nitrous oxide; cuff volume and pressure; times of onset and resolution of symptoms; management; and any contributing factors.

Results Our searches generated a total of 164 articles from PubMed and 191 from Embase. After excluding 45 duplicates, 312 reports were left. Of these, there were 53 reports meeting the eligibility criteria (Fig. 1), reporting a total of 56 patients. The reports were published between 1994 and 2014; our analysis of four reports was restricted to the abstract as we were unable to secure translations. Patient ages ranged from 9 months to 75 years.

Recurrent laryngeal nerve damage Our review identified 16 cases of recurrent laryngeal nerve injury [5–19]. Of these, 13 were reported with the cLMA and its variants [5–16], two with the ProSeal LMATM [17, 18] and one with the Air-QTM LMA [19] (Table 1). Of all the cranial nerve injuries, damage to the recurrent laryngeal nerve was most likely to present with significant morbidity. Uniquely among the nerve injuries described in this review, it may present both © 2014 The Association of Anaesthetists of Great Britain and Ireland

Anaesthesia 2015, 70, 344–359

intraoperatively and postoperatively. The recurrent laryngeal nerve ascends in the tracheo-oesophageal groove and enters the larynx by passing under the lower border of the inferior constrictor muscle at the apex of the piriform fossa [5]. When correctly placed, the tip of the LMA cuff is positioned at the inferior border of the hypopharynx, against the upper oesophageal sphincter at the level of the C6–C7 vertebral interspace (Fig. 2). The nerve is vulnerable to injury as it enters the larynx, where it can be pinched against the cricoid cartilage (Figs. 2 and 3). Unilateral paralysis results in the vocal cord’s resting in the paramedian position. In this situation, the laryngeal inlet will be adequate and airway obstruction is unlikely. However, inadequate glottic closure might result in hoarseness, and laryngeal incompetence may lead to impaired coughing and risk of aspiration. Bilateral palsy may cause the vocal cords to be positioned in the midline, with narrowing of the glottic aperture. This may present as dyspnoea or inspiratory stridor, and occasionally severe respiratory distress [20]. Respiratory difficulty, requiring intubation or tracheostomy, and permanent voice impairment are the most severe complications. In the cases reported, it was sometimes difficult to establish the diagnosis. For instance, the authors of one report could not ascertain whether the vocal cord palsy (presenting as voice impairment) after LMA use was due to the device, or to the presence of a cervical spine osteophyte compressing the nerve close to the trachea and oesophagus [21]. Furthermore, vocal cord palsy after the use of supraglottic airway devices closely resembles arytenoid cartilage subluxation and is thus likely to be under-diagnosed [22, 23]. In the 16 cases we reviewed, the time of presentation varied from immediately after the insertion of the LMA to up to 48 h later. Hoarseness was the most common manifestation, followed by dysphagia and dysphonia. Four reports documented bilateral injury. Two patients required tracheostomy [9, 17]; one presented intra-operatively, the other 2 h after removal [9]. A child required mechanical ventilation [12]. The fourth patient developed features of unilateral paralysis (aphonia and difficulty in coughing) but was found to have bilateral paralysis when inspected through the fibreoptic bronchoscope [16]. Both the patients in whom the Pro-Seal was used also needed tracheosto345

Thiruvenkatarajan et al. | Cranial nerve injuries with supraglottic airway devices

Number of records identified from PubMed and Embase (n = 355)

Included

Eligibility

Screening

Identification

Anaesthesia 2015, 70, 344–359

Trigeminal nerve Reports (n = 23) Patients (n = 25) Lingual (n = 22) Inferior alveolar (n = 2) Infra-orbital (n = 1)

Records identified through manual search (n = 3)

Duplicates removed (n = 45)

Relevant articles screened (n = 313) Full text articles assessed for eligibility (n = 91) Reports included (n = 53) (Includes abstract only data from 3 Japanese and one Danish report)

Recurrent laryngeal nerve Reports (n = 16) Patien ts (n = 17)

Excluded: Based on title and abstract (n = 222)

Excluded (n = 38) Not meeting the Inclusion criteria (n = 37) Unable to get Japanese abstract (n = 1)

Hypoglossal nerve Reports and patients (n = 11)

Glossopharyngeal nerve Patients (n = 3)

Figure 1 Flow diagram of the literature search and selection process.

mies; one was performed in the operating room at the time of the injury; the other required the procedure two weeks after the anaesthetic, following aspiration pneumonia. Co-existing disorders in the form of spinocerebellar ataxia [17] and CREST (calcinosis, Raynaud’s phenomenon, oesophageal dysmotility, sclerodactyly and telangiectasia) with Sjogren’s syndrome [18] were present in these patients. Flexible fibreoptic bronchoscopy or nasal endoscopy may help in the immediate diagnosis of the more serious bilateral presentations and assist in identifying conditions that might require urgent treatment such as mucosal trauma and arytenoid dislocation. Electromyography, CT scan, MRI scan or video stroboscopy may also help in distinguishing arytenoid dislocation [24] and other causes of cord palsy. Of the 16 patients, five were managed conservatively with recovery times varying from 1 h up to 19 months. Partial recovery was noted in four patients. Laryngoplasty, thyroplasty and mechanical ventilation were required in three separate patients [6, 7, 12]. Persisting voice damage with partial recovery of vocal cord function was noted in five patients [6, 7, 13, 14, 17]. 346

Cuff pressure was described in only one patient [17]. Cuff volume was mentioned in nine patients and all except one [13] had an appropriate volume. Cuff overinflation was postulated in two reports [13, 18]. Other contributory factors suggested were: incorrect size of device for the patient [6, 8, 13]; the use of lidocaine jelly [13, 16]; long duration of surgery [9]; poor insertion technique [22]; reduced mucosal circulation [17, 18] and activation of the inflammatory cascade [14, 17] (Table 4). Hoarseness after supraglottic airway use cannot always be attributed to transient laryngeal irritation [6]; the possibility of recurrent laryngeal nerve injury should always be considered. Persistent cough, speech impairment or respiratory compromise warrant careful examination and follow-up with referral to an otolaryngologist [7]. Management options other than conservative treatment include voice therapy, glucocorticoids and surgical interventions for persisting palsies. Finally, though supraglottic airway may be preferable to tracheal intubation in professional voice users, such patients should be informed pre-operatively about this recurrent laryngeal nerve injury and its consequences [5]. © 2014 The Association of Anaesthetists of Great Britain and Ireland

© 2014 The Association of Anaesthetists of Great Britain and Ireland

NR

17

58/F

4/M

54/M

64/F

Cros et al. [14]

Daya et al. [5]

36

52

67

83

74/M

19/M

NR

44/M

Cros et al. [14]

Lowinger et al. [7] Brimacombe et al. [13]

NR

21/M

Bruce et al. [10] Minoda et al. (A) [11] Sacks et al. [12]

120

50/M

Chan and Grillone [6]

48

98

63/F

57/M

Weight; kg

Endo et al. [9]

Classic LMA Wadelek et al. [8]

Reference

Age; years/ sex

4

3

4

3

4

2

NR

5

5

3

4

60

60

90

60

50

90

NR

75

60

425

70

Duration of Size of surgery; device min

Yes

Yes

Yes

Yes

Yes

Yes

NR

Yes

NR

Yes

No

N2O use

NR

30 ml

20 ml

35 ml

20 ml

7 ml

NR

NR

NR

20 ml

33 ml

Cuff pressure/ volume measured

Unilateral

Unilateral

Unilateral

Unilateral

Unilateral

Bilateral

Unilateral

Unilateral

Unilateral

Bilateral

Unilateral

Laterality

Dysphonia, laryngeal incompetence, fluid aspiration, sore throat Dysphagia, hoarseness, laryngeal incompetence Hoarseness

Dysphonia, aphonia Hoarseness, sore throat

Hoarseness, dysphagia Inspiratory stridor

Hoarseness

Hoarseness, dysphonia

Hoarseness dysphagia, tongue deviation Shortness of breath

Symptoms/ signs

NR

Few hours

Conservative

NR

Few hours

48 h

Conservative

Thyroplasty

Intubation, ventilation

NR

CT scan, Injection laryngoplasty Conservative

Tracheostomy

MRI

Management

Few hours

24 h

End of case

NR

2 days

PACU

2h

PACU

Time of onset

Table 1 Summary of recurrent laryngeal nerve injuries following use of different types of supraglottic airway device.

3 months

6 months (partial)

2 months

18 months (partial) 3 months (partial)

24 h

2 months

5 months

19 months (partial)

1 month

Few months

Time to recovery

Pressure neuropraxia

Over-inflation of cuff

Poor technique, too small a mask, over-inflation of cuff, lidocaine jelly Ischaemic inflammatory reaction

Intra-operative cuff pressure increase NR

NR

NR

Too small a mask?, Semi-supine position Long duration, arytenoid compression Too large a mask?

Contributing factors

Thiruvenkatarajan et al. | Cranial nerve injuries with supraglottic airway devices Anaesthesia 2015, 70, 344–359

347

348

60

67/F

75/F

NR

50

41

45/F

71/F

72

39/F

Weight; kg

3

3

4

3

4

Size of device

NR

117

60

97

30

Duration of surgery; min

No

Yes

No

Yes

Yes

N2O use

NR

40 ml

60 cm H2O

15 ml

30 ml

Cuff pressure/ volume measured

Unilateral

Unilateral

Bilateral

Bilateral

Unilateral

Laterality

Vocal cord bowing to right

Dysphagia, hoarseness, coughing

Laryngeal oedema

Aphonia

Hoarseness

Symptoms/ signs

After insertion

24 h

Intraoperative

Immediate

2 days

Time of onset

PACU, post-anaesthesia recovery unit; MRI, magnetic resonance imaging; NR, not recorded; A, abstract data.

Air-QTM LMA Blais et al. [19]

Kawauchi et al. [18]

Lloyd Jones and Hegab [15] Inomata et al. [16] Pro-Seal Carron et al. [17]

Reference

Age; years/ sex

Table 1 (continued)

LMA adjustment

Minitracheostomy

Tracheostomy

Conservative

NR

Management

Immediate

2 months (partial)

NR

40 min

3 weeks

Time to recovery

Mechanical force

Reduced mucosal blood flow, altered cricoarytenoid function, inflammatory cascade Double the recommended volume, reduced mucosal blood flow

Lidocaine jelly

Pressure neuropraxia

Contributing factors

Anaesthesia 2015, 70, 344–359 Thiruvenkatarajan et al. | Cranial nerve injuries with supraglottic airway devices

© 2014 The Association of Anaesthetists of Great Britain and Ireland

Thiruvenkatarajan et al. | Cranial nerve injuries with supraglottic airway devices

Anaesthesia 2015, 70, 344–359

Infra-orbital nerve

Lingual nerve Inferior alveolar nerve Hypoglossal nerve

Mental nerve

Hyoid bone

C6

Recurrent laryngeal nerve

Figure 2 Schematic illustration of the position of a supraglottic device in relation to the cranial nerves of interest.

Trigeminal nerve injury The three divisions of this nerve are the ophthalmic, maxillary and mandibular. Of all the branches of the trigeminal nerve, the lingual nerve, a peripheral branch of the mandibular nerve, was the most commonly injured by supraglottic airway use. The inferior alveolar branch of the mandibular nerve can also be damaged. The only branch of the maxillary nerve at risk is the infra-orbital nerve [25]. We identified 25 cases of nerve injuries related to the peripheral branches of the trigeminal nerve (Table 2). Of these, 22 were lingual nerve injuries [24, 26–44], two inferior alveolar [45, 46] and one infra-orbital [25]. Of the 22 lingual nerve injuries, 14 were associated with the use of the cLMA and its variants [24, 26–37]. The Pro-Seal, LMA SupremeTM, i-gelâ and COPATM (cuffed oropharyngeal airway) had two associated injuries each [38–44]. The lingual nerve lies immediately beneath the mucosa on the inner surface of the mandible just below the roots of the third molar tooth [37]. It then passes forward to the side of the tongue, crossing the hyoglossus muscle, and divides into terminal branches © 2014 The Association of Anaesthetists of Great Britain and Ireland

Figure 3 Anatomical preparation of a laryngeal mask airway in situ. The cuff is inflated next to the point where the thyroid and cricoid cartilages meet (arrow) where the recurrent laryngeal nerve is situated. At this location, the nerve enters the larynx from within the tracheo-oesophageal groove. ‘Oesoph’ denotes oesophagus (reproduced with permission from [21]). that lie directly under the mucosa of the tongue. The nerve is susceptible to injury by compression or stretching by supraglottic airway devices at two points: the lateral edge of the tongue base; and the medial aspect of the inner surface of the mandible close to the third molar [47, 48] (Figs. 2 and 4). Transient numbness of the anterior tongue and altered taste perception (dysgeusia) were the most common presentations. Numbness at the tip and the lateral half of the tongue can also be present, and can affect speech articulation [49]. Symptoms can occur as early as a few minutes after insertion to as late as 24 h. Lingual nerve injury has to be differentiated from hypoglossal nerve damage, which presents predominantly as motor weakness of the tongue. No specialised investigations are required but a subjective sensory assessment of the tongue is useful, and aids in the monitoring of recovery [48]. The cuff pressure was described in only three patients [24, 25, 29]; the cuff volume was recorded in 11 patients. The contributing factors discussed included: nitrous oxide use; malpositioning; incorrect sizing; prolonged duration of surgery; and chemical neuronitis secondary to the use of wrong lubricant (Table 4). Recovery occurred in all patients with lingual nerve injury without specific treatment; this took from a few hours to up to six months. Similar self-limiting symptoms are frequently encountered after dental 349

350

42/F

54

NR

26/M

Laxton [37]

NR

73/M

Ostergaard et al. (A) [35] Ahmed and Yentis [36]

NR

27/F

Majumder and Hopkins [34]

NR

40/M

NR

60

NR

36/F

Cardoso et al. [30]

NR

20/M

32/F

Fideler and Schroeder [29]

101 75

Koyama et al. (A) [32] Gaylard [33]

50/F 55/F

Foley et al. [27]
cio et al. [28] Ina

79

27/M

21/M

Foley et al. [27]

NR

NR

Weight; kg

Arimune (A) [31]

36/F

52/F

El Toukhy and Tweedie [26]

Lingual nerve Classic LMA variants Dhillon and O’Leary [24]

Reference

Age; years/ sex

3

4

NR

3

4

NR

NR

3

4

3 4

5

4

4

Size

35

30

140

20

60

NR

NR

120

60

70 150

45

180

60

Duration of surgery; min

Yes

Yes

Yes

Yes

Yes

Yes

NR

NR

NR

Yes NR

No

No

No

N2O use

20 ml

30 ml

NR

20 ml

20 ml

NR

NR

30 ml

50 cm H2O

NR 20 ml

40 ml

No

< 60 cm H2O

Cuff pressure/ volume measured

Unilateral

Unilateral

NR

Bilateral

Unilateral

NR

Unilateral

Bilateral

Unilateral

Unilateral Bilateral

Unilateral

Bilateral

Bilateral

Laterality

Numbness, taste disturbance Numbness, taste disturbance Taste disturbance Numbness, taste disturbance Numbness, taste disturbance

Numbness, taste disturbance Numbness, taste disturbance, Numbness Numbness, taste disturbance Numbness, taste disturbance Numbness, taste disturbance Taste disturbance Taste loss

Numbness, taste disturbance

Symptoms/ signs

Few hours

PACU

1 week

PACU

24 h

24 h

NA

1h

Few hours

PACU 1h

Few hours

PACU

Instant

Time of onset

Table 2 Summary of trigeminal nerve injuries following use of different types of supraglottic airway devices.

Conservative

NR

NR

Conservative

Conservative

NR

NR

Conservative

Conservative

Conservative Conservative

Conservative

Conservative

Conservative

Management

4 months (90% recovery)

6 months ? partial NR

6 weeks

2 months

6 months

NA

3 weeks

4 days

4 weeks 2 weeks

4 weeks

6 weeks

4 weeks

Time to recovery

Multiple factors

NR

NR

Nerve compression

NR

Malposition

NR

Small size

TMJ subluxation

NR Small size

NR

EBUS induced LMA movement NR

Contributing factors

Anaesthesia 2015, 70, 344–359 Thiruvenkatarajan et al. | Cranial nerve injuries with supraglottic airway devices

© 2014 The Association of Anaesthetists of Great Britain and Ireland

© 2014 The Association of Anaesthetists of Great Britain and Ireland

Laffon et al. [44] Inferior alveolar nerve Classic LMA variants Hanumanthiah et al. [45] i-gel Theron and Loyden [46]

Rujirojindakul et al. [41] COPA Kadry and Popat [43]

Rujirojindakul et al. [41] i-gel Renes et al. [42]

Brimacombe and Keller [39] Supreme LMA Thiruvenkatarajan et al. [40]

Pro-Seal Brimacombe et al. [38]

Reference

Table 2 (continued)

65

85

NR

35/M

NR/F

60

29/F

32/F

53

78

69/M

33/F

65

61

45/F

43/F

76

74

Weight; kg

64/F

61/M

Age; years/ sex

4

4

9

10

3

4

4

3

4

5

Size

60

120

20

65

45

45

75

105

45

150

Duration of surgery; min

NR

Yes

Yes

Yes

No

NR

No

No

No

Yes

N2O use

NR

30 ml

38 ml

40 ml

NR

NR

No

No

2 ml

20 ml

Cuff pressure/ volume measured

NR

Unilateral

Bilateral

Unilateral

Tongue tip

Bilateral

Tongue tip

Tongue tip

Unilateral

Unilateral

Laterality

Lower lip numbness and ulcer

Lower lip numbness

Numbness, taste disturbance Numbness

Numbness, taste disturbance Numbness

Numbness

Numbness

Numbness

Numbness, taste disturbance

Symptoms/ signs

NR

PACU

PACU

PACU

24 h

Few hours

24 h

PACU

2h

Immediate

Time of onset

Conservative

Conservative

Conservative

Conservative

Conservative

Conservative

Conservative

Conservative

Conservative

Conservative

Management

4 days (partial)

2 weeks

2h

10 days

2 weeks

8 weeks

2 weeks

3 weeks

10 h

15 days

Time to recovery

i-gel design

Vascular compression

Cuff over inflation

Multiple factors

NR

i-gel design

Small size, cuff pressure not monitored Excess cuff pressure

Non-supine, shoulder surgery, N2O, long duration Big size

Contributing factors

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351

352

Thiruvenkatarajan et al. | Cranial nerve injuries with supraglottic airway devices COPA, cuffed oropharyngeal airway; NR, not recorded; PACU; post-anaesthesia care unit; A, abstract data; EBUS, endobronchial ultrasound; TMJ, Temporomandibular joint.

Reduced fixation tab to lip distance 14 days Conservative PACU infra-orbital nerve Supreme LMA Carron et al. [25]

64/F

68

4

80

No

60 cm H2O

NR

Numbness, swelling, (midline upper lip)

Time to recovery Management Reference

Table 2 (continued)

Age; years/ sex

Weight; kg

Size

Duration of surgery; min

N2O use

Cuff pressure/ volume measured

Laterality

Symptoms/ signs

Time of onset

Contributing factors

Anaesthesia 2015, 70, 344–359

Third molar

Lingual plate Lingual nerve

Figure 4 Illustration of the lingual nerve entering the mouth at the level of the 3rd molar tooth on the lingual side of the mandible, where it is close to the periosteum and prone to compression. procedures [27]. However, although lingual nerve damage does not lead to severe morbidity, disturbances in taste, speech and the tongue trauma can cause significant discomfort until recovery occurs. The inferior alveolar nerve lies superficially between the third molar tooth and the ramus of the mandible, where it is vulnerable to injury [45] (Fig. 2). Injury presents as sensory loss of the lower lip resulting from neuropraxia of the terminal branch (the mental nerve); this creates the potential for subsequent lip trauma. Both reported cases (cLMA and i-gel) recovered within a week. The wide buccal stabiliser and the integral bite block design of the i-gel makes it bulkier and harder around the lips compared with other devices. This could obscure the anaesthetist’s view of the lower lip looking from the head end of the patient; accidental taping of the lower lip to the lower bite block of the i-gel might also contribute to nerve injury [46]. The only reported case of infra-orbital nerve injury occurred with the LMA Supreme [25]. The maxillary nerve continues as the infra-orbital nerve and innervates the lower eyelid, upper lip, cheek and side of the nose (Fig. 2). Injury to the infra-orbital nerve presents as swelling and sensory loss of the upper lip. In the report, the fixation tab of the device was fixed in close contact with the upper lip [25]. The fixation tab is a new feature, absent from other models of supraglottic airway devices; it is a rectangular structure projecting over the upper lip facilitating insertion and fixation. According to the instructions from the manufacturer, the distance between the fixation tab and upper lip © 2014 The Association of Anaesthetists of Great Britain and Ireland

Thiruvenkatarajan et al. | Cranial nerve injuries with supraglottic airway devices

should be between 0.5 and 2 cm [50]. If the fixation tab is found to press against the upper lip, a larger size is warranted. The authors felt that this injury could have been avoided by following the manufacturer’s instructions. However, it may be difficult to maintain this distance intra-operatively as the tape or tie securing the device is passed across the fixation tab, making it difficult to inspect the distance. In addition, changes in cuff pressure during anaesthesia may alter this distance [25].

Hypoglossal nerve injury Our review identified 11 cases of hypoglossal nerve injury [29, 51–60]. Of these, nine were after the cLMA and two with the Pro-Seal (Table 3). Nine were isolated injuries, the other two were bilateral. Eight cases were reported in adults, two in adolescents and one in an infant. Nitrous oxide was used in five patients and the data were missing in three reports. The hypoglossal nerve lies above the greater horn of the hyoid bone at the angle of mandible before turning forwards and medially towards the tongue [51]. The nerve is vulnerable to neuropraxia from compression injury due to an overinflated or malpositioned cuff at the level of the greater horn of the hyoid bone [61] (Fig. 2). The nerve supplies the ipsilateral intrinsic and extrinsic muscles of the tongue apart from the palatoglossus [52, 62]. Ipsilateral injury presents as tongue deviation to the affected side together with unilateral muscle weakness [53, 63]. Bilateral injury manifests as fasciculations, motor weakness of the tongue, dysarthria and dysphagia [54]. The onset time varied from soon after awakening to as late as first postoperative day. However, diagnosis can be confused by the coexistence of other cranial nerve injuries. A review of hypoglossal nerve injury after tracheal intubation revealed that a quarter of the patients also had ipsilateral lingual nerve damage [62]. These two nerves lie closely together at the lateral margin of the tongue where they can be compressed [62]. One of the two reports with a Pro-Seal also had features of lingual nerve injury [60]. As opposed to lingual nerve injury, where both the cuff and the shaft of the supraglottic airway can create pressure points, hypoglossal nerve stretching is only related to the cuff of the device. © 2014 The Association of Anaesthetists of Great Britain and Ireland

Anaesthesia 2015, 70, 344–359

Internal carotid artery dissection and central venous catheterisation through the internal jugular vein are other rare causes of hypoglossal nerve injury [62]. Patients with severe or bilateral symptoms should be referred to a neurologist for further management (peripheral vs central tongue palsy). Extracranial Doppler, duplex sonography or MRI may be required to differentiate device-induced injury from internal carotid artery dissection [62]. Spontaneous recovery is possible with conservative rehabilitative measures such as diet modifications, steroids and speech therapy [62]. All the reported patients recovered completely within a few days to months, except one case where residual motor weakness of the tongue persisted [57]. Cuff pressure was recorded in only one case whereas the volume was mentioned in seven cases. In two cases, an incorrect size was thought to contribute to the injury [51, 58, 61]. Other contributory factors outlined from the reports were: use of nitrous oxide; presence of a hypopharyngeal haematoma in an anticoagulated patient; extreme head rotation along with prolonged duration; coexistent rheumatoid arthritis; and cuff overinflation and malposition (Tables 3 and 4).

Multiple cranial nerve injuries There were two cases of combined lingual and glossopharyngeal nerve injuries [31, 44] and one report of a combination of lingual, glossopharyngeal and hypoglossal nerve injuries [29]. Glossopharyngeal nerve injury presents as taste and sensory disturbance to the posterior third of the tongue, loss of the pharyngeal reflex, dysphagia, and deviation of the uvula to the opposite side [47]. Temporomandibular joint subluxation was thought to account for the combination of these three nerve injuries [29]. There was one case of Tapia’s syndrome, which is a combined extracranial ipsilateral injury of the recurrent laryngeal and hypoglossal nerves [8]. Pressure neuropraxia of both nerves due to an overinflated cuff and stretching are the proposed mechanisms. The hypoglossal nerve is situated on the most lateral prominence of the transverse process of the first cervical vertebra and crosses the vagus nerve [8]; the nerves are likely to be stretched over this prominence. The patient described also had features of lingual nerve injury [8]. 353

354

28/F

NR

62

36

NR

NR

83

88

NR

NR

NR

9.7

Weight; kg

5

4

3

4

4

5

4

4

3

4

1.5

Size

210

300

3h

NR

NR

45 min

90

NR

120

60

45

Duration of surgery; min

Yes

Yes

Yes

Yes

No

Yes

No

NR

NR

NR

No

N2O Use

40 ml

30 ml

20 ml

25 ml

NR

40 ml

20 ml

NR

20 ml

50 cm H2O

NR

Cuff pressure/ volume measured

Unilateral

Unilateral

Unilateral

Unilateral

Unilateral

Bilateral

Bilateral

Unilateral

Unilateral

Unilateral

Unilateral

Laterality

Dysphagia, tongue numbness

Dysphagia, dysarthria

Tongue deviation, dysphagia Dysarthria, tongue deviation Dysphagia, dysarthria, tongue fasciculations & motor weakness Dysphagia, dysarthria, tongue weakness, 7 kg weight loss Tongue deviation, dysphagia Dysphagia, dysarthria Dysphagia, tongue deviation

Tongue deviation Tongue deviation

Symptoms/ signs

Steroids MRI

CNS consult Speech therapy

2h

Immediate

Immediate

1 day

Conservative

Steroids, vitamin B12

Vitamin B12, steroids

3h

1h

Conservative

4h

Conservative

Steroids MRI

3h

6h

Conservative

Few hours

Management Conservative, speech therapy Conservative

2h

Time of onset

NR, not recorded; TMJ, temporomandibular joint; MRI, magnetic resonance imaging; CNS, central nervous system.

€ mpelmann and Tru Cook [60]

24/M

62/F

Nagai et al. [58]

Pro-Seal Trivedi [59]

55/M

54/M

Stewart and Lindsay [54]

King and Street [57]

15/M

Sommer et al. [52]

46/M

15/M

Rodriguez et al. [53]

Umapathy et al. [56]

48/M

Lo [51]

Classic LMA variants Trujillo et al. [55]

32/F

9M/M

Reference

Fideler and Schroeder [29]

Age; years/ sex

Table 3 Summary of hypoglossal nerve injuries following use of different types of supraglottic airway devices.

4 months

6 weeks

1 week

8 days

Non-neutral head position, N2O, prolonged duration N2O, prolonged surgery

NR

Anticoagulation

NR

Cuff over inflation, malposition

6 weeks

6 weeks

Extreme head rotation, prolonged surgery

NR

TMJ subluxation hypothesised NR

NR

Contributing factors

4 weeks

15 days

2 weeks

4 days

3 weeks

Time to recovery

Anaesthesia 2015, 70, 344–359 Thiruvenkatarajan et al. | Cranial nerve injuries with supraglottic airway devices

© 2014 The Association of Anaesthetists of Great Britain and Ireland

Thiruvenkatarajan et al. | Cranial nerve injuries with supraglottic airway devices

Table 4 Possible contributing factors to cranial nerve injuries with supraglottic airway devices. Anaesthesia-related factors Excessive cuff inflation, > 60 cm H2O Failure to measure and adjust the cuff pressure Inappropriate size selection Peri-operative manipulation of the device Nitrous oxide use Malpositioning Traumatic insertion Poor technique Chemical neuronitis Patient-related factors Diabetes mellitus Collagen vascular disorders Peripheral vascular disorders Surgery-related factors Lateral position Extreme head rotation Prone position Prolonged duration

Discussion Injuries to cranial nerves from supraglottic airway devices present in different ways. In the reports we retrieved, symptoms were minimal with trigeminal and hypoglossal nerve neuropraxia, and the outcome was good. Conversely, most patients with recurrent laryngeal injury presented with significant dysfunction. Injuries can be complex in that, while many causative mechanisms have been proposed, many happened apparently for no identifiable reason. Awareness of these injuries and their presentation is crucial in subsequent management. In the postoperative setting, analgesics and residual anaesthetic drugs might mask symptoms and signs, leading anaesthetists to overlook the problem. Although information on contributing factors and/ or the mechanism of injury was missing in over half the reports included, two factors are worthy of mention. The first is intracuff pressure. Even at recommended cuff volumes, intracuff pressure can exceed the recommended values [64] and potentially exceed the critical capillary perfusion pressure of the pharyngeal mucosa [65, 66]. Nitrous oxide diffusion into the cuff can increase the cuff volume up to 38% within 30 min and up to 50% before the end of anaesthesia [67]. Furthermore, if the cuff is inflated to the maximal recommended volume, the cuff pressure can double within 60 min [68]. The cuff pressure varies between individ© 2014 The Association of Anaesthetists of Great Britain and Ireland

Anaesthesia 2015, 70, 344–359

ual patients for a given volume of air [1]. A recent study shows that, even in the absence of nitrous oxide, the cuff pressure of the LMA can exceed the recommended level in about three quarters of the patients; cuff pressure was frequently over 120 cmH2O [69]. Measuring the cuff pressure, and keeping it below 60 cmH2O, has been shown to reduce pharyngolaryngeal complications by 70% [3]. However, apart from the manufacturers’ recommendation of a maximum cuff pressure of 60 cmH2O, there are no clinical guidelines endorsing this particular value, so others may be better. Second, the case reports suggest that components other than the cuff can also cause nerve injury. These include the shaft of the device compressing the lingual nerve at the periosteum close to the third molar, and the fixation tab of the LMA Supreme causing infraorbital nerve damage. It is interesting to speculate whether differences in device design might influence their propensity to cause nerve injury – do the wider shaft and the more rigid material of the LMA Supreme make it more likely to damage the lingual nerve injury compared with the cLMA, for instance? Current knowledge suggests that directly measured pressures exerted on the oropharyngeal mucosa were very low and similar among cLMA, LMA Supreme and i-gel [70, 71], so one might assume that they have a comparable safety profile in this respect. As many anaesthetists are more aware of peripheral nerve damage during anaesthesia and surgery, some comparative features are relevant. Most cranial nerve injuries are identified within the first 24 h after surgery whereas peripheral neuropathies are usually identified after 48 h [72]. Anaesthetic factors play a predominant role in the presentation of cranial nerve injuries, whereas surgical and predisposing factors have a greater role in causing peripheral nerve injuries [73]. Most of the cranial nerve injuries (apart from some recurrent laryngeal nerve injuries) are neuropraxic in nature. Hypertension, smoking and diabetes are wellrecognised risk factors of peripheral nerve injury [74]; however, data on a similar risk factors for cranial nerve injury are lacking, though it seems plausible that those with pre-existing neuropathic disease might be more vulnerable. Lastly, while electromyography is widely used in the management of peripheral nerve injury [75], its utility was not described in the reports of cranial 355

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Thiruvenkatarajan et al. | Cranial nerve injuries with supraglottic airway devices

nerve injury after supraglottic airway use. Nonetheless, electromyography was employed in the management of hypoglossal nerve palsy as a complication of tracheal intubation [76] implying its possible role as a diagnostic tool in nerve palsy after supraglottic airway use. If cranial nerve injury is suspected, details of the timing and progression of the symptoms, with a particular emphasis on the predisposing factors should be elicited [75]. Attempts should be made to ascertain the mechanism of injury and a basic neurological examination should be undertaken, concentrating on the sensory and motor deficits. Simple assessments such as light touch, pinprick and two-point discrimination should be used to record baseline function and help monitor progression. Documentation should include schematic illustration of the areas involved, and the nature of the injury should be well described. Patients with minor neuropraxic injuries should be reassured about recovery and followed up by telephone. Appropriate consultations should be organised as early as possible for complicated presentations, including neuropathic pain. Although we systematically sought case reports and series for this review, we did not include data about cranial nerve injuries that might have appeared within observational or randomly assigned studies of supraglottic ariways. We did not contact device manufacturers nor national registries of medical device problems. We are unable to calculate estimates of frequency as the true number of nerve injuries is unknown and we have no reliable denominator. Furthermore, the evidence for specific causative factors is moderate at best. Nevertheless, we have compiled the largest collection of published reports to date and we are in a position to make two comments for practice. The first relates to device size. Currently, most manufacturers recommend weight-based selection of size of supraglottic airway device. However, Asai and Brimacombe argue against using a single factor in size selection, since there is no definite relationship between gender, weight, height, dimensions of the oropharynx and body mass index [77]. Individual anatomical variations in relation to the shape and size of the oropharynx are relevant when choosing a size of LMA. A larger size mask where the cuff is not visible in the back of the mouth and the cuff volume inflated 356

to the minimum necessary seems to be an appropriate technique [77]. The second relates to causation. We suggest that cranial nerve injuries may not be completely preventable and should not always be assumed to represent sub-standard care. Nevertheless, we advocate the use of a cuff manometer and recommend that the cuff pressure is maintained below < 60 cm H2O. A careful, gentle insertion technique; proper fixation; and early identification and correction of misplacement will also help. In terms of research, large prospective epidemiological studies are needed to determine the true incidence of these injuries, as well as improving our understanding of them. A better knowledge of the anatomical configuration of new devices might also contribute to greater safety, and nerve injury should be incorporated as a secondary adverse outcome in future studies evaluating supraglottic airway devices. The differences between various devices in causing these injuries are also worthy of further investigation.

Acknowledgements The authors thank Dr Michael Draper, research librarian at Barr Smith Library, University of Adelaide, for his help in the literature search. We would like to thank Mr Tavik Morgenstern, School of Medical Sciences, University of Adelaide, Australia, for sketching the diagrams depicted in this manuscript. We also thank Dr John Currie, senior visiting anaesthetist of our hospital for his valuable guidance and inputs in preparing the revision.

Competing interests No external funding and no competing interests declared.

References 1. Hernandez MR, Klock PA Jr, Ovassapian A. Evolution of the extraglottic airway: a review of its history, applications, and practical tips for success. Anesthesia and Analgesia 2012; 114: 349–68. 2. Cook T, Howes B. Supraglottic airway devices: recent advances. Continuing Education in Anaesthesia Critical Care and Pain 2011; 11: 56–61. 3. Seet E, Yousaf F, Gupta S, Subramanyam R, Wong DT, Chung F. Use of manometry for laryngeal mask airway reduces postoperative pharyngolaryngeal adverse events: a prospective, randomized trial. Anesthesiology 2010; 112: 652–7.

© 2014 The Association of Anaesthetists of Great Britain and Ireland

Thiruvenkatarajan et al. | Cranial nerve injuries with supraglottic airway devices 4. Haghighi M, Mohammadzadeh A, Naderi B, Seddighinejad A, Movahedi H. Comparing two methods of LMA insertion; classic versus simplified (airway). Middle East Journal of Anesthesiology 2010; 20: 509–14. 5. Daya H, Fawcett WJ, Weir N. Vocal fold palsy after use of the laryngeal mask airway. The Journal of Laryngology and Otology 1996; 110: 383–4. 6. Chan TV, Grillone G. Vocal cord paralysis after laryngeal mask airway ventilation. The Laryngoscope 2005; 115: 1436–9. 7. Lowinger D, Benjamin B, Gadd L. Recurrent laryngeal nerve injury caused by a laryngeal mask airway. Anaesthesia and Intensive Care 1999; 27: 202–5. 8. Wadełek J, Kolbusz J, Orlicz P, Staniaszek A. Tapia’s syndrome after arthroscopic shoulder stabilisation under general anaesthesia and LMA. Anaesthesiology Intensive Therapy 2012; 44: 31–4. 9. Endo K, Okabe Y, Maruyama Y, Tsukatani T, Furukawa M. Bilateral vocal cord paralysis caused by laryngeal mask airway. American Journal of Otolaryngology 2007; 28: 126–9. 10. Bruce I, Ellis R, Kay N. Nerve injury and the laryngeal mask airway. The Journal of Laryngology and Otology 2004; 118: 899–901. 11. Minoda Y, Yoshimine K, Nagata E, Kawaguchi Y, Sakamoto M, Takehara A. Vocal cord palsy after the use of a laryngeal mask airway. Masui 2003; 52: 291–3. 12. Sacks MD, Marsh D. Bilateral recurrent laryngeal nerve neuropraxia following laryngeal mask insertion: a rare cause of serious upper airway morbidity. Pediatric Anesthesia 2000; 10: 435–7. 13. Brimacombe J, Keller C. Recurrent laryngeal nerve injury with €sthesiologie Intensivmedizin Notfallthe laryngeal mask. Ana medizin Schmerztherapie 1999; 34: 189–92. 14. Cros A, Pitti R, Conil C, Giraud D, Verhulst J. Severe dysphonia after use of a laryngeal mask airway. Anesthesiology 1997; 86: 498–500. 15. Lloyd Jones F, Hegab A. Recurrent laryngeal nerve palsy after laryngeal mask airway insertion. Anaesthesia 1996; 51: 171– 2. 16. Inomata S, Nishikawa T, Suga A, Yamashita S. Transient bilateral vocal cord paralysis after insertion of a laryngeal mask airway. Anesthesiology 1995; 82: 787–8. 17. Carron M, Stefano V, Ori C. Bilateral vocal cord paralysis and oedema after placement of a ProSealTM laryngeal mask airway in a patient with spinocerebellar ataxia. British Journal of Anaesthesia 2009; 102: 890–1. 18. Kawauchi Y, Nakazawa K, Ishibashi S, Kaneko Y, Ishikawa S, Makita K. Unilateral recurrent laryngeal nerve neuropraxia following placement of a ProSeal laryngeal mask airway in a patient with CREST syndrome. Acta Anaesthesiologica Scandinavica 2005; 49: 576–8. 19. Blais A, Merchant RN, Blackie SP. Transient vocal cord deformity caused by a laryngeal mask airway device during flexible fibreoptic bronchoscopy. Canadian Journal of Anesthesia 2012; 59: 724–5. 20. Bruch JM. Hoarseness in adults. In: Deschler DG, ed. UpToDate. Waltham, MA: UpToDate, 2014, www.uptodate.com (accessed 25/04/2014). 21. Lehnert B, Prescher A, Neuschaefer-Rube C. Is laryngeal mask airway-related vocal chord palsy always laryngeal mask airway-related? British Journal of Anaesthesia 2008; 101: 882. 22. Rontal E, Rontal M. Vocal cord paralysis after laryngeal mask airway ventilation. Laryngoscope 2006; 116: 1527–8. 23. Rosenberg MK, Rontal E, Rontal M, Lebenbom-Mansour M. Arytenoid cartilage dislocation caused by a laryngeal mask © 2014 The Association of Anaesthetists of Great Britain and Ireland

24.

25. 26.

27.

28.

29.

30.

31. 32.

33.

34.

35.

36. 37. 38.

39.

40.

41.

42.

43.

Anaesthesia 2015, 70, 344–359

airway treated with chemical splinting. Anesthesia and Analgesia 1996; 83: 1335–6. Dhillon SS, O’Leary K. Lingual nerve paralysis after endobronchial ultrasound utilizing laryngeal mask airway. Journal of Bronchology and Interventional Pulmonology 2012; 19: 72–4. Carron M, Freo U, Ori C. Sensory nerve damage after the use of the LMA SupremeTM. Anesthesiology 2010; 112: 1055–6. El Toukhy M, Tweedie O. Bilateral lingual nerve injury associated with classic laryngeal mask airway: a case report. European Journal of Anaesthesiology 2012; 29: 400–1. Foley E, Mc Dermott T, Shanahan E, Phelan D. Transient isolated lingual nerve neuropraxia associated with general anaesthesia and laryngeal mask use: two case reports and a review of the literature. Irish Journal of Medical Science 2010; 179: 297–300. In
acio R, Bastardo I, Azevedo C. Lingual Nerve Injury: a complication associated with the classic laryngeal mask airway? The Internet Journal of Anesthesiology 2010; 23: 2. Fideler FJ, Schroeder TH. Cranial nerve injuries from a laryngeal mask airway. European Journal of Anaesthesiology 2009; 26: 980–1. Cardoso HE, Kraychete DC, Lima Filho JA, Garrido LS, Rocha AP. Temporary lingual nerve dysfunction following the use of the laryngeal mask airway: report. Revista Brasileira de Anestesiologia 2007; 57: 410–3. Arimune M. Taste disturbance after general anesthesia with classic laryngeal mask airway. Masui 2007; 56: 820–1. Koyama T, Ichizawa A, Fukami N, Arai K, Hirata S, Mishima S. Taste loss following the use of the laryngeal mask airway. Masui 2006; 55: 445–6. Gaylard D. Lingual nerve injury following the use of the laryngeal mask airway. Anaesthesia and Intensive Care 1999; 27: 668. Majumder S, Hopkins P. Bilateral lingual nerve injury following the use of the laryngeal mask airway. Anaesthesia 1998; 53: 184–6. Ostergaard M, Kristensen B, Mogensen T. Reduced sense of taste as a complication of the laryngeal mask use. Ugeskrift for Laeger 1997; 159: 6835–6. Ahmad N, Yentis S. Laryngeal mask airway and lingual nerve injury. Anaesthesia 1996; 51: 707–8. Laxton C. Lingual nerve paralysis following the use of the laryngeal mask airway. Anaesthesia 1996; 51: 869–70. Brimacombe J, Clarke G, Keller C. Lingual nerve injury associated with the ProSeal laryngeal mask airway: a case report and review of the literature. British Journal of Anaesthesia 2005; 95: 420–3. Brimacombe J, Keller C. Salivary gland swelling and lingual nerve injury with the ProSeal laryngeal mask airway. European Journal of Anaesthesiology 2005; 22: 954–5. Thiruvenkatarajan V, Van Wijk RM, Elhalawani I, Barnes A-M. Lingual nerve neuropraxia following use of the Laryngeal Mask Airway Supreme. Journal of Clinical Anesthesia 2014; 26: 65–8. Rujirojindakul P, Prechawai C, Watanayomnaporn E. Tongue numbness following laryngeal mask airway SupremeTM and igelTM insertion: two case reports. Acta Anaesthesiologica Scandinavica 2012; 56: 1200–3. Renes S, Zwart R, Scheffer G, Renes S. Lingual nerve injury following the use of an i-gel laryngeal mask. Anaesthesia 2011; 66: 226–7. Kadry M, Popat M. Lingual nerve injury after use of a cuffed oropharyngeal airway. European Journal of Anaesthesiology 2001; 18: 264–6. 357

Anaesthesia 2015, 70, 344–359

Thiruvenkatarajan et al. | Cranial nerve injuries with supraglottic airway devices

re M, Mercier C, Fusciardi J. Transient lingual 44. Laffon M, Ferrandie and glossopharyngeal nerve injury: a complication of cuffed oropharyngeal airway. Anesthesiology 2001; 94: 719–20. 45. Hanumanthaiah D, Masud S, Ranganath A. Inferior alveolar nerve injury with laryngeal mask airway: a case report. Journal of Medical Case Reports 2011; 5: 1–3. 46. Theron A, Loyden C. Nerve damage following the use of an igel supraglottic airway device. Anaesthesia 2008; 63: 441. €ndorff G, Sesterhenn AM, Kremer B. From 47. Windfuhr JP, Schlo the expert’s office: localized neural lesions following tonsillectomy. European Archives of Oto-Rhino-Laryngology 2009; 266: 1621–40. 48. Graff-Radford SB, Evans RW. Lingual nerve injury. Headache 2003; 43: 975–83. 49. Piagkou M, Demesticha T, Skandalakis P, Johnson EO. Functional anatomy of the mandibular nerve: consequences of nerve injury and entrapment. Clinical Anatomy 2011; 24: 143–50. 50. Verghese C, Ramaswamy B. LMA-SupremeTM – a new singleuse LMATM with gastric access: a report on its clinical efficacy. British Journal of Anaesthesia 2008; 101: 405–10. 51. Lo TS. Unilateral hypoglossal nerve palsy following the use of the laryngeal mask airway. The Canadian Journal of Neurological Sciences 2006; 33: 320–1. 52. Sommer M, Schuldt M, Runge U, Gielen-Wijffels S, Marcus M. Bilateral hypoglossal nerve injury following the use of the laryngeal mask without the use of nitrous oxide. Acta Anaesthesiologica Scandinavica 2004; 48: 377–8.
n LH, Castro dCP, V
azquez 53. Rodríguez OA, Miranda HM, Avello LM. Hypoglossal nerve palsy as a complication of the use of laryngeal mask airway. Anales de Pediatria 2009; 70: 312. 54. Stewart A, Lindsay W. Bilateral hypoglossal nerve injury following the use of the laryngeal mask airway. Anaesthesia 2002; 57: 264–5. 55. Trujillo L, Anghelescu D, Bikhazi G. Unilateral hypoglossal nerve injury caused by a laryngeal mask airway in an infant. Pediatric Anesthesia 2011; 21: 708–9. 56. Umapathy N, Eliathamby T, Timms M. Paralysis of the hypoglossal and pharyngeal branches of the vagus nerve after use of a LMA and ETT. British Journal of Anaesthesia 2001; 87: 322. 57. King C, Street M. Twelfth cranial nerve paralysis following use of a laryngeal mask airway. Anaesthesia 1994; 49: 786–7. 58. Nagai K, Sakuramoto C, Goto F. Unilateral hypoglossal nerve paralysis following the use of the laryngeal mask airway. Anaesthesia 1994; 49: 603–4. 59. Trivedi V. Hypoglossal neuropraxia after Plma insertion. A case report. Gujarat Medical Journal 2010; 65: 73–6. €mpelmann P, Cook T. Unilateral hypoglossal nerve injury 60. Tru following the use of a ProSealTM laryngeal mask. Anaesthesia 2005; 60: 101–2. 61. Brain A. Course of the hypoglossal nerve in relation to the position of the laryngeal mask airway. Anaesthesia 1995; 50: 82–3. €demann P. Hypoglossal nerve palsy as complica62. Dziewas R, Lu tion of oral intubation, bronchoscopy and use of the laryngeal mask airway. European Neurology 2002; 47: 239–43. 63. Weissman O, Weissman O, Farber N, et al. Hypoglossal nerve paralysis in a burn patient following mechanical ventilation. Annals of Burns and Fire Disasters 2013; 26: 86. 64. Bein B, Carstensen S, Gleim M, et al. A comparison of the proseal laryngeal mask airwayTM, the laryngeal tube Sâ and the oesophageal–tracheal combitubeTM during routine surgical procedures. European Journal of Anaesthesiology 2005; 22: 341–6. 65. Marjot R. Pressure exerted by the laryngeal mask airway cuff upon the pharyngeal mucosa. British Journal of Anaesthesia 1993; 70: 25–9. 358

66. O’kelly S, Heath K, Lawes E. A study of laryngeal mask inflation. Anaesthesia 1993; 48: 1075–8. 67. Lumb A, Wrigley M. The effect of nitrous oxide on laryngeal mask cuff pressure. Anaesthesia 1992; 47: 320–3. 68. van Zundert AA, Fonck K, Al-Shaikh B, Mortier E. Comparison of the LMA-ClassicTM with the new disposable soft seal laryngeal mask in spontaneously breathing adult patients. Anesthesiology 2003; 99: 1066–71. 69. Rokamp KZ, Secher NH, Møller AM, Nielsen HB. Tracheal tube and laryngeal mask cuff pressure during anaesthesia-mandatory monitoring is in need. BMC Anesthesiology 2010; 10: 20. 70. Eschertzhuber S, Brimacombe J, Kaufmann M, Keller C, Tiefenthaler W. Directly measured mucosal pressures produced by the i-gelTM and laryngeal mask airway SupremeTM in paralysed anaesthetised patients. Anaesthesia 2012; 67: 407–10. 71. Keller C, Brimacombe J. Mucosal pressure and oropharyngeal leak pressure with the ProSeal versus laryngeal mask airway in anaesthetized paralysed patients. British Journal of Anaesthesia 2000; 85: 262–6. 72. Prielipp RC, Warner MA. Perioperative nerve injury: a silent scream? Anesthesiology 2009; 111: 464–6. 73. Sawyer R, Richmond M, Hickey J, Jarrratt J. Peripheral nerve injuries associated with anaesthesia. Anaesthesia 2000; 55: 980–91. 74. Welch MB, Brummett CM, Welch TD, et al. Perioperative peripheral nerve injuries: a retrospective study of 380,680 cases during a 10-year period at a single institution. Anesthesiology 2009; 111: 490–7. 75. Winfree CJ, Kline DG. Intraoperative positioning nerve injuries. Surgical Neurology 2005; 63: 5–18. 76. Streppel M, Bachmann G, Stennert E. Hypoglossal nerve palsy as a complication of transoral intubation for general anesthesia. Anesthesiology 1997; 86: 1007. 77. Asai T, Brimacombe J. Cuff volume and size selection with the laryngeal mask. Anaesthesia 2000; 55: 1179–84.

Appendix Details of the search strategy PubMed (Laryngeal mask*[tw] OR Supraglottic airway*[tw] OR Extraglottic airway* [tw] OR Supra glottic airway*[tw] OR Extra glottic airway* [tw] OR Ultra CPV[tw] OR Ultra clear CPV[tw] OR Ultraflex CPV[tw] OR Aurastraight[tw] OR Auraonce[tw] OR Aura40[tw] OR Auraflex[tw] OR Vital seal[tw] OR King LAD[tw] OR King LAD flexible[tw] OR LMA Classic[tw] OR LMA unique[tw] OR LMA flexible[tw] OR Cobra PLA perilaryngeal airway*[tw] OR Cobra Plus[tw] OR Portex soft seal[tw] OR SLIPA[tw] OR Streamlined liner*[tw] OR igel[tw] OR LMA-prosea[tw] OR LMA-Supreme[tw] OR King/VBM LT/Lt-D[tw] OR King/VBM LTS-D[tw] OR VBM LTS II[tw] OR VBM GLT*[tw] OR Esophageal tracheal tube[tw] OR Rusch Easy Tube[tw] OR Aura-i [tw] OR Air-Q/ILA[tw] OR LMA Fastrach[tw] OR LMA classic excel[tw] OR Baska Mask[tw] OR Guardian © 2014 The Association of Anaesthetists of Great Britain and Ireland

Thiruvenkatarajan et al. | Cranial nerve injuries with supraglottic airway devices

CPV[tw]) AND (Cranial nerves[mh] OR Cranial nerve* [tw] OR Lingual nerve*[tw] OR Inferior Alveolar Nerve* [tw] OR Hypoglossal Nerve* [tw] OR Recurrent Laryngeal Nerve* [tw] OR inferior Laryngeal Nerve* [tw] OR Glossopharyngeal Nerve* [tw] OR Mental nerve*[tw] OR Infra-orbital nerve*[tw] OR Infra-orbital nerve*[tw] OR Cranial nerve injuries[mh] OR Cranial neuropath*[tw] OR cranial neuropraxia*[tw] OR cranial nerve neuropraxia* [tw] OR sensory loss*[tw] OR tongue numbness*[tw] OR dysgeusia*[tw] OR taste* [tw] OR Parageusia*[tw] OR Ageusia*[tw] OR Gustation [tw] OR Lip numbness[tw] OR Lip swelling[tw] OR Swollen lip*[tw] OR Dysphagia*[tw] OR Deglutition Disorder*[tw] OR Swallowing disorder*[tw] OR Dysarth*[tw] OR Tongue immobilit*[tw] OR Hoarseness [tw] OR Stridor[tw] OR Respiratory Aspiration of Gastric Contents[tw] OR Tracheostom*[tw] OR Vocal Cord Paralys*[tw] OR Vocal cord Pals*[tw] OR Vocal fold Pals*[tw] OR vocal cord pares*[tw] OR Vocal cord deformit*[tw] OR Laryngeal Paralys*[tw] OR Laryngeal edema*[tw] OR Laryngeal oedema*[tw] OR Dysphonia [tw] OR Phonation disorder*[tw] OR (lip[tw] AND scabbing [tw])) AND (Case series [tw] OR Case report* [tw] OR Case stud*[tw] OR Case histor*[tw])

Embase ‘Laryngeal mask’/syn ORsupraglottic next/1 airway* OR supraglottic next/1 device* OR extraglottic next/1 airway* OR extraglottic next/1 device* OR ‘supra glottic’ next/1 airway* OR ‘Supra glottic’ next/1 device* OR ‘extra glottic’ next/1 airway* OR ‘extra glottic’ next/1 device* OR ‘Ultra CPV’ OR ‘Ultra clear CPV’ OR ‘Ultraflex CPV’ OR Aurastraight OR Auraonce OR Aura40 OR Auraflex OR’Vital seal’ OR ‘King LAD’ OR ‘LMA Classic’ OR ‘LMA unique’ OR

© 2014 The Association of Anaesthetists of Great Britain and Ireland

Anaesthesia 2015, 70, 344–359

‘LMA flexible’ OR ‘Cobra PLA’ OR ‘perilaryngeal airway’ OR ‘Cobra Plus ‘ OR ‘Portex soft seal’ OR SLIPA OR ‘Streamlined liner of the pharynx airway’ OR ‘i-gel’ OR ‘LMA-proseal’ OR ‘LMA-Supreme’ OR ‘King VBM LT Lt-D’ OR ‘King VBM LTS-D’ OR’VBM LTS II’ OR ‘VBM GLT’ OR ‘gastrolaryngeal tube’ OR ‘Esophageal tracheal tube’ OR ‘Rusch Easy Tube’ OR ‘Aura-i’ OR ‘Air-Q ILA’ OR ‘LMA Fastrach’ OR ‘LMA classic excel’ OR ‘Baska Mask’ OR ‘Guardian CPV’ AND ‘Cranial nerve’/syn OR ‘glossopharyngeal nerve’/syn OR ‘hypoglossal nerve’/syn OR ‘lingual nerve’/syn OR ‘mandibular nerve’/syn OR ‘maxillary nerve’/syn OR ‘trigeminal nerve’/syn OR ‘vagus nerve’/syn OR ‘Inferior Alveolar Nerve’/syn OR ‘recurrent laryngeal Nerve’/syn OR ‘inferior laryngeal’ next/1 nerve* OR mental next/1 nerve* OR ‘mental nerve’/syn OR ‘infra-orbital nerve’/syn OR ‘infra orbital’ next/1 nerve* OR ‘infra-orbital nerves’ OR ‘cranial nerve injury’/syn OR ‘glossopharyngeal nerve injury’/ syn OR ‘hypoglossal nerve injury’/syn OR ‘trigeminal nerve injury’/syn OR ‘vagus nerve injury’/syn OR Cranial next/1 neuropath* OR cranial next/1 neuropraxia* OR sensory next/1 loss* OR tongue next/1 numbness* OR dysgeusia* OR taste/syn OR ageusia/ syn OR Parageusia* OR lip next/1 numbness* OR lip next/1 swelling* OR swollen next/1 lip* OR dysphagia/syn OR dysarthria/syn OR Tongue next/1 immobilit*Hoarseness OR Stridor OR ‘Respiratory Aspiration of Gastric Contents’ OR Tracheostom* OR ‘Vocal Cord Paralysis’/syn OR ‘Vocal cord Palsies’ OR ‘Vocal cord’next/1 deformit* OR Laryngeal next/1 (Paralys* OR edema* OR oedema*) OR Dysphonia/syn OR Phonation next/1 disorder* OR (lip AND scabbing) AND (‘Case study’/syn OR ‘Case report’ OR Case next/1 histor*)

359