Effects of uninterrupted chest compressions on the rescuer's physical condition.

Study Objective: Recent guidelines have emphasized the need for uninterrupted chest compressions. The purpose of this study was to evaluate the rescuer's tolerability of uninterrupted chest compressions.

Methods: Twenty-five healthy subjects performed uninterrupted chest compressions for 7 minutes at a rate of 100 compressions per minute using a training manikin. The quality of chest compressions was assessed in terms of the total number and percentage of chest compressions, compression depth, recoil distance, and duty cycle. Correct chest compression was defined as a depth of 38 to 51 mm. Physiological and laboratory parameters were measured before and after the procedure. Fatigue was measured using a numerical rating scale. Data were compared before and after the procedure.

Results: The participants were 10 emergency physicians and 15 medical students. The compression rate was nearly 100 compressions per minute. The number and percentage of correct compressions decreased gradually after 3 minutes. The compression depth decreased significantly after 2 minutes. The recoil distance and duty cycle were unchanged over 7 minutes. Systolic blood pressure, pulse rate, respiratory rate, numerical rating scale, serum lactate, adrenalin, and noradrenalin increased significantly after the procedure. Noradrenalin levels measured before the procedure were significantly and negatively correlated with the total number and percentage of correct compressions (r = -0.587, P = .004; r = -0.549, P = .008, respectively).

Conclusions: Performing uninterrupted chest compressions for 7 minutes is an arduous procedure. Higher noradrenalin levels before the procedure might be associated with incorrect chest compressions.