ABSTRACT
Infrequent training of artificial ventilation in dental facilities implies poor performance of this procedure under CPR. Gastric inflation is a significant issue when ventilation is performed on an unprotected airway. An Easy Grip (EG) Bag-Valve-Mask Resuscitator, a Laryngeal Tube (LT), size #5, and a SMART BAG (SB) resuscitator, a pressure-limiting device, were tested to assess the respiratory effects especially focussing on prevention of gastric inflation during simulated CPR. Twenty academic dental staff members performed ten ventilations on a manikin during CPR by use of EG, LT and SB in a randomized order. In twelve experiments the oesophageal sphincter pressure was adjusted to 15 mbar (best case), in eight experiments to 0 mbar (worst case scenario). Best case scenario median tidal volume distributions achieved by EG (median 144 ml) and LT (75 ml) did not differ, whereas differences were found between EG and SB (31 ml; p = 0.055) as well as between SB and LT (p = 0.042). None of the values met recommended ranges. Almost no gastric inflation occurred. Worst case scenario ventilation by use of the LT resulted in profoundly lower median gastric inflation volumes (median 13 ml) compared to SB (median 288 ml; p=0.008) and EG (800 ml; p = 0.008). Median tidal volume distributions also differed between LT (225 ml) vs EG (100 ml) (p=0.016) and LT vs SB (19 ml) (p =0.008). Chest compression was delayed in ten experiments by LT insertion for 28 s (median). In a later stage of CPR or in case of mask ventilation difficulties, the LT may serve as a helpful tool in dental facilities. CPR training must focus on the importance of chest compression which must not be discontinued if an LT is inserted. The SB might gain value if higher tidal volumes are achieved, exerting a higher risk of gastric inflation.
