In-hospital factors associated with improved outcome after out-of-hospital cardiac arrest. A comparison between four regions in Norway.

INTRODUCTION: While pre-hospital factors related to outcome after out-of-hospital cardiac arrest (OHCA) are well known, little is known about possible in-hospitals factors related to outcome. HYPOTHESIS: Some in-hospital factors are associated with outcome in terms of survival.
MATERIAL AND METHODS: An historical cohort observational study of all patients admitted to hospital with a spontaneous circulation after OHCA due to a cardiac cause in four different regions in Norway 1995-1999: Oslo, Akershus, Østfold and Stavanger.
RESULTS: In Oslo, Akershus, Østfold and Stavanger 98, 84, 91 and 186 patients were included, respectively. Hospital mortality was higher in Oslo (66%) and Akershus (64%) than in Østfold (56%) and Stavanger (44%), P=0.002. By multivariate analysis the following pre-arrest and pre-hospital factors were associated with in-hospital survival: age <or=71 years, better pre-arrest overall performance, a call-receipt-start CPR interval <or=1 min, and no use of adrenaline (epinephrine). The in-hospital factors associated with survival were: no seizures, base excess >-3.5 mmol l(-1), body temperature <or=37.8 degrees C, and serum glucose <or=10.6 mmol l(-1) 1-24 h after admittance with OR (95% CI) 2.72 (1.09-8.82, P=0.033), 1.12 (1.02-1.23, P=0.016), 2.67 (1.17-6.20, P=0.019) and 2.50 (1.11-5.65, P=0.028), respectively. Pre-arrest overall function, whether adrenaline was used, body temperature, the occurrence of hypotensive episodes, and the degree of metabolic acidosis differed between the four regions in parallel with the in-hospital survival rates.
CONCLUSION: Both pre-arrest, pre- and in-hospital factors were associated with in-hospital survival after OCHA. It seems important also to report in-hospital factors in outcome studies of OCHA. The design of the study precludes a conclusion on causability.