Aspiration and the laryngeal mask airway: three cases and a review of the literature
C. Keller1,
J. Brimacombe2,*,
J. Bittersohl3,
P. Lirk1 and
A. von Goedecke1
1 Department of Anaesthesia and Intensive Care Medicine, Leopold-Franzens University, Innsbruck, Austria. 2 James Cook University, Department of Anaesthesia and Intensive Care, Cairns Base Hospital, Australia. 3 Department of Anaesthesiology and Intensive Care Medicine, Philipps-University, Marburg, Germany
* Corresponding author. E-mail: jbrimaco{at}bigpond.net.au
Accepted for publication May 25, 2004.
 |
Abstract
|
---|
The primary limitation of the laryngeal mask airway (LMA®)
is that it does not reliably protect the lungs from regurgitated stomach content. We describe three cases of aspiration associated with the LMA, including the first brain injury, the first death, and the first associated with the intubating LMA, and review the 20 specific case reports of aspiration associated with the LMA that we were able to find described in the literature.
Keywords:
complications, aspiration pneumonitis
;
complications, mortality
;
equipment, masks, laryngeal mask airway
 |
Introduction
|
---|
Pulmonary aspiration of gastric contents accounts for 5% of respiratory claims against the anaesthesiologist.1 The primary limitation of the laryngeal mask airway (LMA) is that it does not reliably protect the lungs from regurgitated stomach contents, although it may act as a barrier at the level of the upper oesophageal sphincter if it is correctly positioned.2 The incidence of aspiration with the LMA has been estimated at 0.02%,3 which is similar to tracheal intubation in elective patients.4 We describe three cases of aspiration associated with the LMA, including the first brain injury, the first death, and the first associated with the intubating LMA, and review the literature.
 |
Case report 1
|
---|
A 49-yr-old female (ASA Physical Status III, BMI 16 kg m2) with low-grade sepsis presented for incision and drainage of a vaginal abscess. She had a past medical history of gastric surgery for carcinoma and multiple intra-abdominal procedures, but had no symptoms of reflux. On examination she was Mallampati grade 1. The airway management plan was to use a classic LMA; tracheal intubation was not considered necessary as the patient was fasted and had no reflux; and the ProSeal LMA was unavailable. Induction was with fentanyl 100 µg and propofol 120 mg. Maintenance was with propofol 6 mg kg1 h1 in oxygen 30% and air. No neuromuscular blocking agent was given. A size 4 classic LMA was easily inserted by a second year resident at the first attempt using the standard recommended technique and the cuff inflated with 20-ml air. Pressure controlled ventilation was commenced and tidal volumes of 450 ml were easily achieved with peak airway pressures of 15 cm H2O. The LMA and bite block was fixed according to the manufacturer's instructions5 and the patient placed in the lithotomy position. At the start of the procedure, the patient suddenly started vomiting, which was attributed to inadequate anaesthetic depth, and bile-stained fluid was seen in the airway tube. The surgeon was asked to stop, the patient was given oxygen 100%, anaesthesia was deepened, head down tilt applied, and a neuromuscular blocking agent administered. A suction catheter was passed to the end of the airway tube and around 40 ml of bile-stained fluid removed. Ventilation and gas exchange was unaffected. Fibre-optic inspection down the airway tube revealed bile-stained fluid within the trachea. The LMA was removed and the patient easily intubated. The procedure was completed uneventfully. There were no postoperative complications.
 |
Case report 2
|
---|
A 73-yr-old female (ASA Physical Status III, BMI 35 kg m2) presented for bilateral varicose vein surgery, to be done in the supine position. She had a past medical history of adult onset diabetes mellitus, chronic obstructive pulmonary disease, and gastric surgery for cancer. On examination she was Mallampati grade 3. The airway management plan was to use a classic LMA; tracheal intubation was not considered necessary. The anaesthetist was not aware of the past medical history, nor of her symptoms of daily reflux, and a ProSeal LMA was unavailable. Induction was with fentanyl 150 µg and propofol 180 mg. Maintenance was with oxygen 30% in nitrous oxide and sevoflurane 1.5%. Muscle relaxation was with atracurium 20 mg. A size 4 classic LMA was inserted easily by a highly experienced consultant at the first attempt using the standard recommended technique and the cuff inflated to and held constant at 60 cm H2O using a digital manometer. Volume controlled ventilation was commenced with tidal volumes of 600 ml and peak airway pressures of 18 cm H2O. The LMA and bite block was fixed according to the manufacturer's instructions. In the middle of the procedure, bile-stained fluid was seen pouring out of the airway tube into the bacterial filter. The surgeon was asked to stop; the patient was given oxygen 100% and head down tilt applied. Ventilation was possible with the LMA, but gas exchange was poor with
less than 90% when the
was 1. The LMA was removed and the patient easily intubated, but there was no improvement in gas exchange. Fibre-optic inspection showed bile-stained fluid in the trachea. The procedure was stopped and the patient transferred to ICU. On day 3, the patient developed severe adult respiratory distress syndrome (
1.0:
58 mm Hg). She was discharged from the ICU after 56 days with a complete left-sided hemiplegia from a cerebral infarct.
 |
Case report 3
|
---|
A 78-yr-old female (ASA Physical Status II, BMI 32 kg m2) presented for a total hip replacement. She had a past medical history of labile hypertension and a hiatus hernia, but had no symptoms of reflux. On examination she was Mallampati grade 2. The airway management plan was to intubate the patient via the intubating LMA rather than using direct laryngoscopy to attenuate the haemodynamic stress response. Tracheal intubation was considered necessary as the procedure was prolonged and the ProSeal LMA was unavailable. Induction was with methohexitone 80 mg. Maintenance was with isoflurane 0.7% and nitrous oxide in oxygen 30%. Muscle relaxation was with rocuronium 50 mg. A size 4 intubating LMA was inserted easily by a second year resident at the first attempt and the cuff inflated with 30-ml air. Manual ventilation was commenced with tidal volumes of 500 ml and peak airway pressures of 17 cm H2O. Before intubation through the intubating LMA was started, bile-stained fluid was seen in the mouth. The patient was given oxygen 100%, but head down tilt was not applied. Ventilation was possible with the LMA. The intubating LMA was removed and the patient intubated using a laryngoscope. Ventilation was adequate and gas exchange acceptable with a
of 206 mm Hg on oxygen 100%. Fibre-optic inspection revealed bile-stained fluid within the trachea. The procedure was completed and the patient transferred to ICU. The patient developed adult respiratory distress syndrome, renal failure, disseminated intravascular coagulation and septicaemia, and died 85 days later from multi-organ failure.
 |
Literature review
|
---|
We conducted a Medline search for Laryngeal mask, read all the resultant publications and analysed all the reports where case-specific details were given. We found a total of 20 specifically described case reports of aspiration of gastric content associated with the LMA (Table 1). Of the 20 cases of aspiration associated with the LMA, 14 were in adults618 and six in children,1924 19 were with the classic LMA617 1924 and one was with the ProSeal LMA.18 In 14 cases, there were factors that could increase the risk of aspiration, including, in order of frequency, inadequate depth of anaesthesia,9 13 19 21 23 intra-abdominal surgery,7 10 18 upper gastrointestinal disease,9 11 lithotomy position,11 20 patient movement,7 20 exchanging the LMA for a tracheal tube,12 16 full stomach,22 multiple trauma,6 multiple insertion attempts,14 opioids,6 obesity,10 and cuff deflation.7 There is only one report where aspiration occurred where the patient had no risk factors.24 In addition, Kluger and Short,25 in a review of 133 cases of aspiration reported to the Australian Anaesthetic Incident Monitoring Study, documented 27 cases of aspiration associated with the LMA. However, the data from these patients were not separated from aspiration associated with a tracheal tube (n=8), Hudson mask (n=5), and facemask (n=91).
 |
Discussion
|
---|
All three patients in our series were at increased risk of aspiration: the first had gastric surgery and low-grade sepsis; the second had gastric surgery and diabetes; and the third had a hiatus hernia. Both patients with adverse outcomes were elderly, ASA grade III, or both. Although this is the first report of brain injury and death from aspiration associated with the LMA, it is likely that there have been other such events. Given that the LMA has been used in 150 million patients since its release in 1988 (www.lmaco.com), a frequency of 0.02% for aspiration3 and a mortality rate for aspiration of 5% (based on data from the pre-LMA era4), there should have been around 1500 deaths. Perhaps patients with the LMA have a lower mortality rate, as the LMA tends to be used in healthy patients undergoing minor procedures. Perhaps the lack of reporting is related to medico-legal considerations, or journals decline such reports, as it is already established that aspiration can occur with the LMA and that aspiration can cause death.
An assessment of aspiration risk is critical to determining whether the LMA should be used and, to a lesser extent, which type of LMA should be used, as the correctly placed ProSeal LMA can prevent aspiration.2628 The patient should be questioned about upper gastrointestinal disease, focusing on current symptoms and treatment. Unfortunately, there are no data from which to make an evidence-based decision about whether or not symptoms are severe enough to warrant tracheal intubation. Most anaesthesiologists consider that the LMA is contraindicated in patients with gastroesophageal reflux, but a recent survey revealed that 5773% of Australian anaesthesiologists would use the LMA in patients with a history of reflux esophagitis or hiatus hernia provided it was asymptomatic.29 Interestingly, one of our patients had an asymptomatic hiatus hernia. Other factors affecting aspiration risk are fasting status, the use of gastroparetic drugs, the presence/severity of pain, the type/duration/position of surgery being performed, the depth of anaesthesia, and airway obstruction.
All three patients in our series were intubated once a diagnosis of aspiration had been made, even though ventilation was possible with the LMA. We recommend that if pharyngeal regurgitation or pulmonary aspiration is suspected, the patient should be placed in the head-down position, oxygen 100% administered, anaesthesia deepened, suctioning performed and the severity of the regurgitation/aspiration event assessed fibre-optically. The decision about whether to intubate the trachea or continue with the LMA will depend on how well the LMA is functioning, the severity of the regurgitation/aspiration event and the anticipated risk of further regurgitation/aspiration. Removal of the LMA may result in further regurgitation and consideration should be given to intubating the patient fibre-optically via the LMA. Consideration should also be given to passing a gastric tube, but this may also provoke further regurgitation.
In summary, we report the first cases of aspiration-related brain injury and death associated with the LMA, and the first case of aspiration associated with the intubating LMA. In principle, meticulous selection of patients and surgical procedures, optimal management of the placement, maintenance and emergence phases, and use of the ProSeal LMA can reduce the risk of aspiration.
 |
Footnotes
|
---|
This article is accompanied by Editoral II. 
LMA® is the property of Intavent Ltd. 
 |
References
|
---|
1 Caplan RA, Posner KL, Ward RJ, Cheney FW. Adverse respiratory events in anesthesia: a closed claims analysis. Anesthesiology 1990; 72: 82833[ISI][Medline]
2 Keller C, Brimacombe J, Raedler C, Puehringer F. Do laryngeal mask airway devices attenuate liquid flow between the esophagus and pharynx? A randomized, controlled cadaver study. Anesth Analg 1999; 88: 9047[Abstract/Free Full Text]
3 Brimacombe J, Berry A. The incidence of aspiration associated with the laryngeal mask airwaya meta-analysis of published literature. J Clin Anesth 1995; 7: 297305[CrossRef][ISI][Medline]
4 Warner MA, Warner WE, Webber JG. Clinical significance of pulmonary aspiration during the perioperative period. Anesthesiology 1993; 78: 5662[ISI][Medline]
5 Verghese C. LMA-ClassicTM, LMA-FlexibleTM, LMA-UniqueTM. Instruction Manual. Henley-on-Thames: The Laryngeal Mask Company Ltd, 1999
6 Wilkinson PA, Cyna AM, MacLeod DM, et al. The laryngeal mask: cautionary tales. Anaesthesia 1990; 45: 1678[Medline]
7 Griffin RM, Hatcher IS. Aspiration pneumonia and the laryngeal mask airway. Anaesthesia 1990; 45: 103940[ISI][Medline]
8 Koehli N. Aspiration and the laryngeal mask airway. Anaesthesia 1991; 46: 419[Medline]
9 Nanji GM, Maltby JR. Vomiting and aspiration pneumonitis with the laryngeal mask airway. Can J Anaesth 1992; 39: 6970[Abstract]
10 Brain AIJ. The laryngeal mask and the oesophagus. Anaesthesia 1991; 46: 7012
11 Brimacombe J, Berry A. Aspiration and the laryngeal mask airwaya survey of Australian intensive care units. Anaesth Intens Care 1992; 20: 5345[ISI][Medline]
12 Langer A, Hempel V, Ahlhelm T, Heipertz W. [Experience with use of the laryngeal mask in over 1900 general anaesthetics]. Anaesthesiologie Intensivmedizin Notfalmedizin Schmerztherapie 1993; 28: 15660
13 Hamada I. [Vomiting and pulmonary aspiration during the use of the LM]. J Clin Anesth 1991; 15: 121920
14 Miyasaka C. A case of pulmonary aspiration during insertion of LM. J Clin Anesth 1991; 15: 1360
15 Verghese C, Brimacombe J. Survey of laryngeal mask airway usage in 11910 patients: safety and efficacy for conventional and nonconventional usage. Anesth Analg 1996; 82: 12933[Abstract]
16 Vogelsang H, Uhlig T, Schmucker P. [Severe multiorgan failure caused by aspiration with laryngeal mask airway]. Anasthesiol Intensivmed Notfallmed Schmerzther 2001; 36: 635[CrossRef][ISI][Medline]
17 Gaitini LA, Vaida SJ, Somri M, Ben-David B, Hagberg CA. A randomized controlled trial comparing the Proseal laryngeal mask airway with the Sonda Laryngeal Tube in Mechanically Ventilated Patients. Anesthesiology 2002; 96: A1319 (Abstract)
18 Brimacombe J, Keller C. Aspiration of gastric contents during use of a ProSeal laryngeal mask airway secondary to unidentified foldover malposition. Anesth Analg 2003; 97: 11924[Abstract/Free Full Text]
19 Maroof M, Khan RM, Siddique MS. Intraoperative aspiration pneumonitis and the laryngeal mask airway. Anesth Analg 1993; 77: 40910[ISI][Medline]
20 Alexander R, Arrowsmith JE, Frossard RJ. The laryngeal mask airway: safe in the X ray department. Anaesthesia 1993; 48: 734
21 Braun U, Fritz U. [The laryngeal mask in pediatric anesthesia.] Anaesthesiologie Intensivmedizin Notfalmedizin Schmerztherapie 1994; 29: 2868
22 Ismail-Zade IA, Vanner RG. Regurgitation and aspiration of gastric contents in a child during general anaesthesia using the laryngeal mask airway. Paed Anaesth 1996; 6: 3258[ISI][Medline]
23 Lussmann RF, Gerber HR. [Severe aspiration pneumonia with the laryngeal mask.] Anaesthesiologie Intensivmedizin Notfalmedizin Schmerztherapie 1997; 32: 1946
24 Cassinello F, Rodrigo FJ, Munoz-Alameda L, et al. Postoperative pulmonary aspiration of gastric contents in an infant after general anesthesia with laryngeal mask airway (LMA). Anesth Analg 2000; 90: 1457.[Free Full Text]
25 Kluger MT, Short TG. Aspiration during anaesthesia: a review of 133 cases from the Australian Anaesthetic Incident Monitoring Study (AIMS). Anaesthesia 1999; 54: 1926[CrossRef][ISI][Medline]
26 Keller C, Brimacombe J, Kleinsasser A, Loeckinger A. Does the ProSeal laryngeal mask airway prevent aspiration of regurgitated fluid? Anesth Analg 2000; 91: 101720[Abstract/Free Full Text]
27 Brimacombe J, Keller C. Airway Protection with the ProSeal Laryngeal Mask Airway: a case report. Anaesth Intens Care 2001; 29: 28891[ISI][Medline]
28 De Silva KK, Young P. Protection against aspiration with the Proseal laryngeal mask airway. Anaesth Intensive Care 2002; 30: 391[ISI][Medline]
29 Crilly H, McLeod K. Use of the laryngeal mask airwaya survey of Australian anaesthetic practice. Anaesth Intens Care 2000; 28; 224 (Abstract)