Evaluation of pressure-controlled ventilation concepts during cardiopulmonary resuscitation (CPR) in dental chairs.

BACKGROUND: Infrequent training of lay rescuers in cardiopulmonary resuscitation may lead to stomach inflation during ventilation of the unsecured airway. This is caused by a pressure loss of the lower oesophageal sphincter (LOSP) after onset of cardiac arrest. To minimise the risk of stomach inflation, the SMART BAG® (SB), a disposable flow-limited bag-valve-mask resuscitator, has been designed. Aim The aim of this study was to evaluate the occurrence of stomach inflation by use of SB in comparison to two other ventilation devices with respect to the ventilation capability.

METHOD: An Easy Grip® disposable bag-valve-mask resuscitator (EG), an SB and an EG with an interposed T-piece attached to a 0.5 l reservoir bag (EG/R) were compared in a manikin ventilation training setting. Fourteen dentists performed ventilations on a Mini Ventilation Training Analyzer using EG, SB and EG/R with lung compliance (LC) and LOSP being adjusted to 700 ml/kPa and 1.5 kPa (best case) and 500 ml/kPa and 0.5 kPa (worst case) in a randomised order.

RESULTS: Sufficient tidal volumes were obtained by use of all the three test devices regardless of LC or LOSP. No statistical differences were detected between the use of SB and EG/R. Using EG led to statistically larger volumes. Stomach inflation could only be avoided using SB and EG/R at a high LOSP regardless of LC.

CONCLUSION: Even in the worst case scenario, use of SB and EG/R administered sufficient tidal volumes with a significantly smaller stomach inflation compared to EG. Combination of standard bag-valve devices with a reservoir bag may provide similar protection from gastric inflation as the SMART BAG®.