Respiratory arrest outside hospital.

Of 954 attempted resuscitations outside hospital performed by ambulance personnel, 48 patients (5%) had primary respiratory arrest. Comparing this group with those manifesting cardiorespiratory arrest, patients with primary respiratory arrest were significantly more likely to be female (25 of 48 vs 269 of 906-P < 0.005), were more likely to have a non-cardiac cause (67% vs. 22%-P < 0.00001) and more likely to have witnessed arrest. Of all arrests witnessed by ambulance crew, 35% were respiratory arrests. Basic and advanced life-support was delivered sooner. Outcome was significantly better, with 19 patients (40%) being discharged compared to only 49 patients (5.1%) discharged in cases of cardiorespiratory arrest (p < 0.00001). Considering that many respiratory arrests were witnessed by ambulance crew, the type of crew (EMT or paramedic) made no difference to outcome. Our findings suggest that patients manifesting respiratory arrest outside hospital are a heterogeneous group who have a relatively good prognosis regardless of the type of ambulance crew that attends.