Objectives: To determine whether there is an association between bystander mouth-to-mouth ventilation and regurgitation in prehospital cardiac arrest patients.
Design: Prospectively conducted observational study.
Setting: Data were collected from patients treated by the emergency medical service (EMS) systems in three middle-sized or large Finnish urban communities, the Tampere District EMS and the physician-staffed Helicopter EMSs in the Helsinki and Turku areas in southern Finland.
Subjects: The study population consisted of 529 consecutive prehospital cardiac arrest patients with attempted resuscitation. Exclusion criteria were cardiac arrest due to trauma or drug overdose.
Main outcome measures: Regurgitation in prehospital cardiac arrest patients documented by EMS personnel on the scene.
Results: Regurgitation occurred in a fourth of patients. Bystander cardiopulmonary resuscitation (CPR) with mouth-to-mouth ventilation was associated with a significantly increased risk of regurgitation compared with no CPR (P < 0.013) and CPR without ventilations (P < 0.01).
Conclusions: The mode and role of bystander CPR in cardiac arrest needs to be further evaluated.