The incidence of regurgitation during cardiopulmonary resuscitation: a comparison between the bag valve mask and laryngeal mask airway
Introduction
Gastric regurgitation remains an acknowledged complication of cardiac arrest [1]. The risk is further increased during the resuscitation process by pressure changes generated during external chest compressions and positive pressure ventilation through an unprotected airway. In addition to this, cardiac arrest may well occur in patients with full stomachs. Normal protection from gastric regurgitation and consequent pulmonary aspiration is abolished by relaxation of the lower oesophageal sphincter and obtundation of the protective laryngeal reflexes.
During cardiac arrest initial ventilation is commonly performed using a self inflating bag valve mask (BVM), prior to the insertion of another device designed to provide definitive airway security [2]. The conventional definitive airway is recognised to be the cuffed tracheal tube (ETT), but placement requires a considerable period of training and regular practice to achieve competence. To provide training and practice for all health care professionals who might attend a patient suffering cardiac arrest is probably an unattainable goal. For this reason alternative airways, such as the laryngeal mask airway (LMA) and the combitube, which require less training for their use, have been studied to assess their effectiveness in comparison with BVM ventilation 3, 4.
The aim of this study was to assess the comparative incidence of gastric regurgitation associated with the BVM and LMA.
Section snippets
Type of hospital
The Conquest Hospital, Hastings is a 490 bed district general hospital on the South Coast of England. The hospital, which was opened in 1992, serves a population of 168 000 with a significant proportion of elderly residents. All of the acute services are situated on one site facilitating immediate response to cardiac arrests.
Resuscitation services
The hospital has employed a full-time resuscitation training officer (RTO) since 1985. Every ward and department is equipped with a standard cardiac arrest trolley and
Overall incidence and timing of regurgitation
Regurgitation was recorded to have occurred at some stage in 180 of the patients studied (22.6%). The timing of regurgitation is shown in Table 1. Those patients who regurgitated prior to CPR (n=84) were excluded from further analysis as regurgitation could not have been affected by any form of ventilation. Analysis of the remaining 713 patients was split between those patients ventilated with the BVM, those ventilated with the LMA and those ventilated with both devices. The incidence and
Discussion
Our results confirm that gastric regurgitation is a common complication of cardiopulmonary arrest. In this series which excluded patients who responded very quickly to CPR/defibrillation and patients ventilated without the use of a BVM or LMA, some 22.6% (180/797) had recorded evidence of gastric regurgitation. However, 46.7% (84/180) of these were known to have regurgitated before any form of airway management was attempted and it is difficult to suggest any measure to prevent this occurring.
Conclusion
Our results show that, for patients suffering cardiac arrest, there is a high incidence of regurgitation occurring prior to cardiopulmonary resuscitation and during resuscitation with an unprotected airway and BVM. When the LMA is used as the first line airway device, regurgitation during CPR was found to be significantly less likely than when the BVM was used as the first line airway device. This confirms experience reported in earlier studies 3, 7, 8, 9, 10.
Acknowledgements
We thank D. Ruffer for her help in collection of the cardiac arrest data.
References (10)
- et al.
Response to cardiac arrests in a hospital setting: delays in ventilation
Resuscitation
(1996) - et al.
Emergency intubation with the combitube: comparison with the endotracheal airway
Ann Emerg Med
(1993) - et al.
Tidal volumes which are perceived to be adequate for resuscitation
Resuscitation
(1996) - et al.
Guidelines for the basic management of the airway and ventilation during resuscitation. A Statement by the Airway and Ventilation Management Working Group of the European Resuscitation Council
Resuscitation
(1996) The use of the laryngeal mask airway in CPR
Resuscitation
(1994)