Gastric rupture associated with use of the laryngeal mask airway during cardiopulmonary resuscitation
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《英国医生杂志》
1 Wansbeck General Hospital, Ashington NE63 9JJ, 2 James Cook University Hospital, Middlesbrough TS4 3BW
Correspondence to: nhaslam@doctors.org.uk
Introduction
This is the first report of rupture of the stomach caused by massive gastric dilation associated with the use of the laryngeal mask airway. Gastric rupture has previously been reported with facemask ventilation4 and a misplaced endotracheal tube.5
A large volume of gas may enter the stomach with only a small tidal leak during positive pressure ventilation with a laryngeal mask airway. Our patient's lungs were hand ventilated for 25 minutes, and we estimated that the volume of the pneumoperitoneum was more than six litres. This volume is consistent with a tidal oesophageal leak of just 20 ml per breath over this time. A volume of six litres is much greater than that known to cause gastric rupture. In a cadaver study (n = 11) gastric rupture occurred at a mean gastric volume of 2670 (SD 410) ml and mean pressure of 73 (SD 13) mm Hg.6 We found it easy to exceed these pressures with an adult resuscitation bag. The maximum pressure we could generate with a 1600 ml self inflating bag for one and two handed use against a closed aperture was 160 mm Hg and 300 mm Hg respectively (personal experiment).
Successful use of the laryngeal mask for positive pressure ventilation in anaesthesia is based on the avoidance of gas leak. Gas leak becomes more likely at greater airway pressure.2 7 8 Gastric inflation during cardiopulmonary resuscitation is associated with the use of large tidal volume, short inspiratory time, and reduced respiratory compliance.9-11 External force applied is a potent way to reduce respiratory compliance, as is gastric dilation itself. The European Resuscitation Council's guidelines recommend an inspiratory time of 1-2 seconds.12 Brimacombe and colleagues recommend limiting airway pressure to less than 20 cm H2O during lung inflation and the use of small tidal volumes (8-10 ml/kg).13 Brain also recommends that if a gas leak is detected it must be immediately corrected because of the risk of gastric inflation and must be actively excluded by listening over the neck and abdomen with a stethoscope. Although gastric inflation led to gastric rupture in our patient, a more likely complication is regurgitation of gastric contents and pulmonary aspiration.
The Resuscitation Council (UK)'s guidelines for the laryngeal mask airway give advice contrary to Brain.14 The guidelines state, "If a laryngeal mask airway has been inserted, attempts can be made to perform continuous chest compressions, uninterrupted during ventilation" and recommend that chest compressions need to be interrupted for ventilation only if "excessive gas leakage results in inadequate ventilation of the lungs." Furthermore, the guidelines assert that "any gas leaking from between the laryngeal mask and the larynx will tend to pass up through the mouth rather than being forced into the patient's stomach." We believe that these statements are wrong. Chest compression synchronous with lung inflation will result in dangerously high airway pressure and should be used with caution with a laryngeal mask airway. We also consider that a pharyngeal gas leak is highly indicative of an oesophageal leak, and even a small leak can result in dangerous gastric dilation very quickly—for example, 2700 ml, the mean volume at which gastric rupture occurred in cadavers,6 can be attained during intermittent positive pressure ventilation with a tidal gas leak of 30 ml in just seven minutes.
Detection of an oesophageal gas leak by auscultation of the abdomen (as recommended by Brain) or of the chest can be difficult during cardiopulmonary resuscitation. A pharyngeal leak can be easily detected, however, by auscultation of the neck, even in noisy environments. We believe that this procedure should be included in all protocols for non-anaesthetists that relate to the use of the laryngeal mask airway and positive pressure ventilation.
A pressure relief valve may have prevented gastric rupture in this case. All paediatric resuscitation bags include a 40 cm H2O pressure relief valve. Inflation pressures for adults in excess of this are rarely beneficial, and the risk of barotrauma and gastric inflation are similar in adults and children. The inclusion of a pressure relief valve at 40-60 cm H2O as standard for adult bags is worth considering.
A tidal volume of 400-600 ml of oxygen is recommended for adults during cardiopulmonary resuscitation.14 The volume of the standard adult self inflating resuscitation bags (Intersurgical 2000 ml, Ambu 1500 ml, Laerdal 1600 ml) may make this difficult to achieve. These bags are awkward to use, and the inexperienced practitioner has a tendency to deliver very large tidal volumes. Studies have compared self inflating "bag mask valve" ventilation using an adult bag, with ventilation obtained using a 500 ml paediatric bag. These studies showed that healthcare workers obtained similar levels of pulmonary ventilation but produced less gastric inflation with the smaller bag.15 16 The optimum volume for an adult resuscitation bag, particularly for use with the laryngeal mask airway, is worth re-evaluating. In adults, use of a 750-1000 ml self inflating bag with a 40 cm H2O pressure relief valve would seem to be ideal for short to medium term ventilation with a laryngeal mask.
We believe that the common risk of gastric inflation with the facemask and laryngeal mask, and the associated risks of pulmonary aspiration of gastric contents and gastric rupture, requires appropriate emphasis in cardiopulmonary resuscitation guidelines.
Gastric inflation is a dangerous complication of using laryngeal mask airways in advanced life support
Contributors: NH prepared the manuscript, did the literature searches, and revised the manuscript; GCC prepared the manuscript; and JD prepared and revised the manuscript.
Funding: None.
Competing interests: None declared.
References
Pennant JH, Walker MB. Comparison of the endotracheal tube and laryngeal mask in airway management by paramedic personnel. Anesth Analg 1992;74: 531-4.
Weiler N, Latorre F, Eberle B, Goedecke R, Heinrichs W. Respiratory mechanics, gastric insufflation pressure, and air leakage of the laryngeal mask airway. Anesth Analg 1997;84: 1025-8.
Ho-Tai LM, Devitt JH, Noel AG, O'Donnell MP. Gas leak and gastric insufflation during controlled ventilation: facemask versus laryngeal mask airway. Can J Anaesth 1998;45: 206-11.
Smally AJ, Ross MJ, Huot CP. Gastric rupture following bag-valve-mask ventilation. J Emerg Med 2002;22(1): 27-9.
Miller JS, Itani KM, Oza MD, Wall MJ. Gastric rupture with tension pneumoperitoneum: a complication of difficult endotracheal intubation. Ann Emerg Med 1997;30: 343-6.
Rabl W, Ennemoser O, Toibulschw, Ambach E. Iatrogenic rupture of the stomach after balloon tamponade. Two case reports: viscoelastic model. Am J Forensic Med Pathol 1995;16: 135-9.
Devitt JH, Wenstone R, Noel AG, O'Donnell RRT. The laryngeal airway and positive-pressure ventilation. Anesthesiology 1994;80: 550-5.
Brimacombe J. Positive pressure ventilation with the size 5 LMA. J Clin Anesth 1997;9: 113-7.
Wenzel V, Idris AH, Banner MJ, Kubilis PS, Band R, Williams JL, et al. Respiratory system compliance decreases after cardiopulmonary resuscitation and stomach inflation: impact of large and small volumes on calculated peak airway pressures. Resuscitation 1988;38: 113-8.
Idris AH, Wenzel V, Banner MJ, Melker RJ. Small tidal volumes minimize gastric inflation during cardiopulmonary resuscitation with an unprotected airway. Circulation 1995;92: I760.
Melker RJ, Banner MJ. Ventilation during CPR: two-rescuer standards reappraised. Ann Emerg Med 1985;14: 397-402.
De Latorre F, Nolan J, Robertson C, Chamberlain D, Baskett P. European resuscitation council guidelines 2000 for adult advanced life support. Resuscitation 2001;48: 211-21.
Brimacombe JR, Brain AIJ, Berry AM. Instruction manual on the use of the LMA in anaesthesia. 4th ed. Maidenhead: Intavent Research, 1999.
Resuscitation Council (UK) 2000 Guidelines. www.resus.org.uk/pages/als.htm (accessed 4 October 2004).
Wenzel V, Idris AH, Dorges V, Nolan JP, Parr MJ, Gabrielli A, et al. The respiratory system during resuscitation: a review of the history, risk of infection during assisted ventilation, respiratory mechanics, and ventilation strategies for patients with an unprotected airway. Resuscitation 2001;49: 123-34.
Dorges V, Ocker H, Wenzel V, Sauer C, Schmucker P. Emergency airway management by non-anaesthesia house officers: a comparison of three stratergies. J Accid Emerg Med 2001;18(2): 90-4.(Nathaniel Haslam, clinica)
Correspondence to: nhaslam@doctors.org.uk
Introduction
This is the first report of rupture of the stomach caused by massive gastric dilation associated with the use of the laryngeal mask airway. Gastric rupture has previously been reported with facemask ventilation4 and a misplaced endotracheal tube.5
A large volume of gas may enter the stomach with only a small tidal leak during positive pressure ventilation with a laryngeal mask airway. Our patient's lungs were hand ventilated for 25 minutes, and we estimated that the volume of the pneumoperitoneum was more than six litres. This volume is consistent with a tidal oesophageal leak of just 20 ml per breath over this time. A volume of six litres is much greater than that known to cause gastric rupture. In a cadaver study (n = 11) gastric rupture occurred at a mean gastric volume of 2670 (SD 410) ml and mean pressure of 73 (SD 13) mm Hg.6 We found it easy to exceed these pressures with an adult resuscitation bag. The maximum pressure we could generate with a 1600 ml self inflating bag for one and two handed use against a closed aperture was 160 mm Hg and 300 mm Hg respectively (personal experiment).
Successful use of the laryngeal mask for positive pressure ventilation in anaesthesia is based on the avoidance of gas leak. Gas leak becomes more likely at greater airway pressure.2 7 8 Gastric inflation during cardiopulmonary resuscitation is associated with the use of large tidal volume, short inspiratory time, and reduced respiratory compliance.9-11 External force applied is a potent way to reduce respiratory compliance, as is gastric dilation itself. The European Resuscitation Council's guidelines recommend an inspiratory time of 1-2 seconds.12 Brimacombe and colleagues recommend limiting airway pressure to less than 20 cm H2O during lung inflation and the use of small tidal volumes (8-10 ml/kg).13 Brain also recommends that if a gas leak is detected it must be immediately corrected because of the risk of gastric inflation and must be actively excluded by listening over the neck and abdomen with a stethoscope. Although gastric inflation led to gastric rupture in our patient, a more likely complication is regurgitation of gastric contents and pulmonary aspiration.
The Resuscitation Council (UK)'s guidelines for the laryngeal mask airway give advice contrary to Brain.14 The guidelines state, "If a laryngeal mask airway has been inserted, attempts can be made to perform continuous chest compressions, uninterrupted during ventilation" and recommend that chest compressions need to be interrupted for ventilation only if "excessive gas leakage results in inadequate ventilation of the lungs." Furthermore, the guidelines assert that "any gas leaking from between the laryngeal mask and the larynx will tend to pass up through the mouth rather than being forced into the patient's stomach." We believe that these statements are wrong. Chest compression synchronous with lung inflation will result in dangerously high airway pressure and should be used with caution with a laryngeal mask airway. We also consider that a pharyngeal gas leak is highly indicative of an oesophageal leak, and even a small leak can result in dangerous gastric dilation very quickly—for example, 2700 ml, the mean volume at which gastric rupture occurred in cadavers,6 can be attained during intermittent positive pressure ventilation with a tidal gas leak of 30 ml in just seven minutes.
Detection of an oesophageal gas leak by auscultation of the abdomen (as recommended by Brain) or of the chest can be difficult during cardiopulmonary resuscitation. A pharyngeal leak can be easily detected, however, by auscultation of the neck, even in noisy environments. We believe that this procedure should be included in all protocols for non-anaesthetists that relate to the use of the laryngeal mask airway and positive pressure ventilation.
A pressure relief valve may have prevented gastric rupture in this case. All paediatric resuscitation bags include a 40 cm H2O pressure relief valve. Inflation pressures for adults in excess of this are rarely beneficial, and the risk of barotrauma and gastric inflation are similar in adults and children. The inclusion of a pressure relief valve at 40-60 cm H2O as standard for adult bags is worth considering.
A tidal volume of 400-600 ml of oxygen is recommended for adults during cardiopulmonary resuscitation.14 The volume of the standard adult self inflating resuscitation bags (Intersurgical 2000 ml, Ambu 1500 ml, Laerdal 1600 ml) may make this difficult to achieve. These bags are awkward to use, and the inexperienced practitioner has a tendency to deliver very large tidal volumes. Studies have compared self inflating "bag mask valve" ventilation using an adult bag, with ventilation obtained using a 500 ml paediatric bag. These studies showed that healthcare workers obtained similar levels of pulmonary ventilation but produced less gastric inflation with the smaller bag.15 16 The optimum volume for an adult resuscitation bag, particularly for use with the laryngeal mask airway, is worth re-evaluating. In adults, use of a 750-1000 ml self inflating bag with a 40 cm H2O pressure relief valve would seem to be ideal for short to medium term ventilation with a laryngeal mask.
We believe that the common risk of gastric inflation with the facemask and laryngeal mask, and the associated risks of pulmonary aspiration of gastric contents and gastric rupture, requires appropriate emphasis in cardiopulmonary resuscitation guidelines.
Gastric inflation is a dangerous complication of using laryngeal mask airways in advanced life support
Contributors: NH prepared the manuscript, did the literature searches, and revised the manuscript; GCC prepared the manuscript; and JD prepared and revised the manuscript.
Funding: None.
Competing interests: None declared.
References
Pennant JH, Walker MB. Comparison of the endotracheal tube and laryngeal mask in airway management by paramedic personnel. Anesth Analg 1992;74: 531-4.
Weiler N, Latorre F, Eberle B, Goedecke R, Heinrichs W. Respiratory mechanics, gastric insufflation pressure, and air leakage of the laryngeal mask airway. Anesth Analg 1997;84: 1025-8.
Ho-Tai LM, Devitt JH, Noel AG, O'Donnell MP. Gas leak and gastric insufflation during controlled ventilation: facemask versus laryngeal mask airway. Can J Anaesth 1998;45: 206-11.
Smally AJ, Ross MJ, Huot CP. Gastric rupture following bag-valve-mask ventilation. J Emerg Med 2002;22(1): 27-9.
Miller JS, Itani KM, Oza MD, Wall MJ. Gastric rupture with tension pneumoperitoneum: a complication of difficult endotracheal intubation. Ann Emerg Med 1997;30: 343-6.
Rabl W, Ennemoser O, Toibulschw, Ambach E. Iatrogenic rupture of the stomach after balloon tamponade. Two case reports: viscoelastic model. Am J Forensic Med Pathol 1995;16: 135-9.
Devitt JH, Wenstone R, Noel AG, O'Donnell RRT. The laryngeal airway and positive-pressure ventilation. Anesthesiology 1994;80: 550-5.
Brimacombe J. Positive pressure ventilation with the size 5 LMA. J Clin Anesth 1997;9: 113-7.
Wenzel V, Idris AH, Banner MJ, Kubilis PS, Band R, Williams JL, et al. Respiratory system compliance decreases after cardiopulmonary resuscitation and stomach inflation: impact of large and small volumes on calculated peak airway pressures. Resuscitation 1988;38: 113-8.
Idris AH, Wenzel V, Banner MJ, Melker RJ. Small tidal volumes minimize gastric inflation during cardiopulmonary resuscitation with an unprotected airway. Circulation 1995;92: I760.
Melker RJ, Banner MJ. Ventilation during CPR: two-rescuer standards reappraised. Ann Emerg Med 1985;14: 397-402.
De Latorre F, Nolan J, Robertson C, Chamberlain D, Baskett P. European resuscitation council guidelines 2000 for adult advanced life support. Resuscitation 2001;48: 211-21.
Brimacombe JR, Brain AIJ, Berry AM. Instruction manual on the use of the LMA in anaesthesia. 4th ed. Maidenhead: Intavent Research, 1999.
Resuscitation Council (UK) 2000 Guidelines. www.resus.org.uk/pages/als.htm (accessed 4 October 2004).
Wenzel V, Idris AH, Dorges V, Nolan JP, Parr MJ, Gabrielli A, et al. The respiratory system during resuscitation: a review of the history, risk of infection during assisted ventilation, respiratory mechanics, and ventilation strategies for patients with an unprotected airway. Resuscitation 2001;49: 123-34.
Dorges V, Ocker H, Wenzel V, Sauer C, Schmucker P. Emergency airway management by non-anaesthesia house officers: a comparison of three stratergies. J Accid Emerg Med 2001;18(2): 90-4.(Nathaniel Haslam, clinica)