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The purpose of the present study was to evaluate the cardiopulmonary resuscitation (CPR) skills of medical students after a 2-h basic life support class (n = 129) and 6 months later (n = 113). Mean +/- SD written test score decreased from 6.4 +/- 0.7 to 6.2 +/- 0.8 (P = 0.03). Mean +/- SD breaths delivered before CPR decreased from 2.9 +/- 0.6 to 2.2 +/- 1.2 (P = 0.0001), ventilation rate increased from 12.2 +/- 1.9 to 14.3 +/- 5.0 breaths/min (P = 0.0001), tidal volume increased from 0.75 +/- 0.2 to 0.8 +/- 0.31 (P = 0.11), minute ventilation from 9.1 +/- 2.6 to 10.8 +/- 3.61 (P = 0.0001), and stomach inflation from 13 +/- 22 to 18 +/- 27% of CPR breaths (P = 0.11). Mean +/- SD chest compression/min decreased from 56 +/- 9 to 54 +/- 12 (P = 0.34), depth of chest compression increased from 41 +/- 6 to 46 +/- 7 mm (P = 0.0001), hands held incorrectly on the thorax increased from 22 +/- 27 to 23 +/- 32% (P = 0.59), and leaning on the chest from 4 +/- 12 to 18 +/- 28% of compressions (P0.0001). In summary, ventilation skills were unpredictable; there was only a 5% chance that a given student would achieve the same mouth-to-mouth ventilation performance in both the BLS class and 6 months later. Despite the respiratory mechanics of the CPR manikin which prevented stomach inflation much better than an unconscious patient with an unprotected airway, stomach inflation occurred repeatedly. Teachers of basic life support classes need to consider the respiratory mechanics of the CPR manikin being used to assure clinically realistic and appropriate mouth-to-mouth ventilation skills.

Anaesthetic residents used bag valve mask (BVM) or mouth mask (MM) ventilation, both with an O2 flow of 15 l min-1 to ventilate 30 ASA I or II anaesthetised patients for 4 min prior to endotracheal intubation. Mean nasopharyngeal O2 was higher with BVM (BVM 95% (S.D. 3%) MM 54% (S.D. 12%)). End tidal CO2 (ETCO2) was similar in both groups (ETCO2% at 4 min: BVM 4.65 (S.D. 0.84) MM 4.53 (S.D. 0.54)) but respiratory rate was faster with BVM (BVM 17 min-1 (S.D. 5) MM 12 min-1 (S.D. 4)). Peak (Paw) and mean (Paw) airway pressures were higher with MM and MM produced significant expiratory pressure [cmH2O: BVM Paw 16.7 (S.D. 5.3) Paw 4.2 (S.D. 2.1) MM: Paw 20.9 (S.D. 5.2) Paw 7.8 (S.D. 2.1)) minimum expiratory pressure: MM 2.4 (S.D. 1.1) BVM 0.2 (S.D. 0.4). Gastric insufflation was detected in two MM and two BVM patients. This tended to be more severe with MM ventilation. Although MM ventilation has some important disadvantages it can be used effectively by resuscitators with little or no experience in its use.

A method of bag valve mask ventilation in which the resuscitator compresses the self inflating bag between their open palm and the side of their body was compared with conventional single and two resuscitator bag valve mask ventilation. Fifteen nurses each ventilated three patients for 4 min following the induction of general anaesthesia, using one method per patient in random order. Tidal volume and peak mask pressures were higher with the two resuscitator technique than with either form of single resuscitator ventilation; There were no significant differences between the two methods of single resuscitator ventilation. Tidal volume: mean (S.D.); 'open palm': 270 ml (160); single resuscitator: 260 ml (220); two resuscitators: 480 ml (210). Peak mask pressure (mmHg): mean (SD); 'open palm': 19 (8); single resuscitator: 17(9); two resuscitator: 28 (11).

Rats were anaesthetized and cooled to cardiac arrest. After 30 min in cardiac arrest, they were rewarmed with artificial respiration. The natural history of cooling and resuscitation was observed, and reversible cardiac arrest was compared with death. The rats had a hind-limb paralysis which recovered apparently completely in about 12 weeks. They also had a permanent weight loss relative to controls. The offspring of the cooled recovered rats were approximately the same number and weights as offspring of their litter-mates, but they grew more slowly. The rats which recovered had a prolonged deficit of vision and hearing.