Should Bite Guards Be Used With Laryngeal Mask Airways In Adults?
Date First Published:
November 17, 2013
Last Updated:
March 11, 2015
Report by:
Elizabeth Heptinstall, Clinical Fellow Neuro-ICU (St George's Hospital, London, UK)
Search checked by:
Louise Heptinstall , St George's Hospital, London, UK
Three-Part Question:
In [adults with an unsecured airway requiring an emergent laryngeal mask airway] should [bite guards be used] to [prevent airway loss during awakening]?
Clinical Scenario:
A 54-year-old man has suffered an out-of-hospital cardiac arrest. The Paramedic Emergency Service have instituted ALS—administering a defibrillatory shock and managing his airway by insertion of a laryngeal mask airway device. Spontaneous circulation has returned but the patient still required airway and breathing support. The resuscitation team leader is just having a conversation with the anaesthetist about securing the airway with an endotracheal tube when the patient has what appears to be a fit. During the tonic phase of the fit, he clenches his teeth and occludes the laryngeal mask airway device. His airway is obstructed, and he subsequently develops pulmonary oedema. You wonder whether these complications could have been prevented with a bite guard.
Search Strategy:
Medline using the PubMed interface date of searching 1 December 2014: ("laryngeal masks"[MeSH Terms] OR ("laryngeal"[All Fields] AND "masks"[All Fields]) OR "laryngeal masks"[All Fields] OR ("laryngeal"[All Fields] AND "mask"[All Fields]) OR "laryngeal mask"[All Fields]) AND "bite block"[All Fields] OR LMA[All Fields] AND "bite block"[All Fields]
The Cochrane Library Issue 12 of 12, 2014: “bite block” ti, ab, kw 3 records 0 relevance.
The Cochrane Library Issue 12 of 12, 2014: “bite block” ti, ab, kw 3 records 0 relevance.
Outcome:
Altogether 18 papers were found in Medline and 3 were found in the Cochrane Library. A further eight relevant papers were found by scanning the references of relevant papers. All relevant papers are summarised in the table
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Successful management of severe upper airway obstruction during emergence of anesthesia in consequence of fracture of deflated laryngeal mask airway due to biting--a case report. Chang WL, Hseu SS, Wang CC et al. 2007 Taiwan | One patient undergoing general anaesthesia with an LMA without a bite block Bit through tube during recovery | Case Report | Complications | Airway obstruction | |
| Acute pulmonary edema from inhalation of the bite-block after anesthesia with a laryngeal mask. Banchereau F, Marié S, Pez H et al. 2001 France | One adult patient who underwent general anaesthesia with an LMA and bite block Inhalation of the bite block during recovery | Case report | Complications | Inhalation of the bite block | |
| Postobstructive pulmonary edema associated with biting a laryngeal mask airway. Shameem A, Malak AM, Rahmani JA 2004 Pakistan | One adult patient undergoing anaesthesia with an LMA without a bite block | Case report | Complications | Pulmonary oedema | |
| Negative Pressure Pulmonary Oedema in a Patient Ventilated with a Laryngeal Mask. Petrou A, Valmas K, Svarna E et al. 2003 Greece | Case report - one adult patient undergoing general anaesthesia with a LMA and no bite block. | One adult patient undergoing general anaesthesia with an LMA and no bite block Bit tube during recovery |
Complications | Pulmonary oedema | |
| Biting the laryngeal mask: an unusual cause of negative pressure pulmonary edema. Devys JM, Balleau C, Jayr C et al. 2000 Canada | One adult patient undergoing anaesthesia with an LMA with no bite block Bit tube during recovery |
Case report - one patient | Complications | Pulmonary oedema | |
| Negative pressure pulmonary edema with laryngeal mask airway use: Recognition, pathophysiology and treatment modalities. Vandse R, Kothari DS, Tripath RS et al. 2012 USA | One patient undergoing general anaesthesia with an LMA without a bite block Bit tube during recovery | Case report | Complications | Pulmonary oedema | |
| Unilateral negative pressure pulmonary edema during anesthesia with a laryngeal mask airway. Sullivan M. 1999 Australia | One adult patient undergoing anaesthesia with a laryngeal mask airway (LMA) without a bite block Bit tube during positioning causing obstruction |
Case report | Complications | Pulmonary oedema | |
| Negative pressure pulmonary edema. Post-obstructive lung edema after use of a laryngeal mask Sickmann K, Seider R, Dahm M, et al. 2005 Germany | One patient undergoing general anaesthesia with an LMA without a bite block Bit tube during recovery | Case report - one patient | Complications | Pulmonary oedema | Only one patient discussed in the broader context of LMA use and complications. |
| A national survey of the use of bite guards and critical incidents involving the laryngeal mask airway. Blackurn JP, Con A, Moore C May-03 UK | Anaesthetists in teaching and non-teaching units across the UK 42% of 451 replied | Postal survey | Biting causing obstruction experienced by respondents | 7.3% of flexible LMA users and 18.1% of standard LMA users | Abstract only published Low response rate |
| Reinforced laryngeal mask severed by biting. Quinlan J. 2002 | One adult patient undergoing anaesthesia with an LMA with no bite block Bit through tube during recovery | Case report | Complications | Airway obstruction |
Author Commentary:
The vast majority of the papers found are case reports, though a single survey suggests that biting of an unguarded laryngeal mask airway (LMA) is not an uncommon event. Complications of biting include airway obstruction and the development of negative pressure pulmonary oedema, neither of which would be welcome events in the resuscitation area. It should be noted that the use of bite guards is not without risk—and a single case report records airway obstruction secondary to inhalation of the guard itself. The riskiest time seems to be during recovery.
Bottom Line:
Bite guards should be used when laryngeal mask airways are employed in the emergency department.
References:
- Chang WL, Hseu SS, Wang CC et al.. Successful management of severe upper airway obstruction during emergence of anesthesia in consequence of fracture of deflated laryngeal mask airway due to biting--a case report.
- Banchereau F, Marié S, Pez H et al.. Acute pulmonary edema from inhalation of the bite-block after anesthesia with a laryngeal mask.
- Shameem A, Malak AM, Rahmani JA. Postobstructive pulmonary edema associated with biting a laryngeal mask airway.
- Petrou A, Valmas K, Svarna E et al.. Negative Pressure Pulmonary Oedema in a Patient Ventilated with a Laryngeal Mask.
- Devys JM, Balleau C, Jayr C et al.. Biting the laryngeal mask: an unusual cause of negative pressure pulmonary edema.
- Vandse R, Kothari DS, Tripath RS et al.. Negative pressure pulmonary edema with laryngeal mask airway use: Recognition, pathophysiology and treatment modalities.
- Sullivan M.. Unilateral negative pressure pulmonary edema during anesthesia with a laryngeal mask airway.
- Sickmann K, Seider R, Dahm M, et al.. Negative pressure pulmonary edema. Post-obstructive lung edema after use of a laryngeal mask
- Blackurn JP, Con A, Moore C. A national survey of the use of bite guards and critical incidents involving the laryngeal mask airway.
- Quinlan J.. Reinforced laryngeal mask severed by biting.