Trends (1998–2006) in hospital mortality for admissions to UK critical care units following cardiopulmonary resuscitation

Introduction

The objective of this study was to investigate trends in hospital mortality for admissions to UK critical care units following cardiopulmonary resuscitation (CPR) for the period 1998–2006.

Methods

A retrospective analysis of the Intensive Care National Audit and Research Centre Case Mix Programme Database of 480,433 admissions to 178 units in England, Wales and Northern Ireland. Admissions, mechanically ventilated in the first 24 hours in the critical care unit and admitted following CPR in the 24 hours before admission, were identified for the period 1 January 1998–31 December 2006.

Results

Mechanically ventilated survivors following CPR accounted for 26,722 (5.6%) of admissions. In total 15,143 (56.7%) died on the admitting critical care unit and 18,573 (70.7%) died before ultimate discharge from acute hospital. Over the 9 years, relative to all admissions, the proportion of patients admitted following CPR decreased from 6.6% to 5.0%; this reduction occurred mainly among those admitted following inhospital CPR. The mean age of admissions following CPR has increased (from 62 to 65 years following inhospital CPR (P < 0.001) and from 58 to 62 years for out-of-hospital CPR (P < 0.001)). Hospital mortality decreased significantly from 70.5% to 69.0% (trend analysis odds ratio (95% confidence interval); 0.98 per year (0.97–0.99) P < 0.001). After adjustment for case mix, the reduction in hospital mortality following inhospital CPR remained significant (0.97 per year (0.96–0.99) P = 0.001) but did not for out-of-hospital CPR (0.99 per year (0.97–1.01) P = 0.43).

Conclusion

In the period 1998–2006, the crude hospital mortality for admissions to UK critical care units following CPR has decreased significantly, and for inhospital CPR this decrease remained significant after adjustment for case mix.