Predictors and outcome of cardiopulmonary resuscitation (CPR) calls in a large haemodialysis unit over a seven-year period.

ABSTRACT

BACKGROUND: Cardiac mortality is the leading cause of death in dialysis patients, with cardiac arrests being most frequent. Our purpose was to determine the epidemiology, predictors and outcomes of calls for cardiopulmonary resuscitation (CPR) occurring in our haemodialysis unit. METHODS: We reviewed retrospectively all calls for CPR occurring in our unit between August 1997 and December 2004 and compared data to a cohort of chronic haemodialysis patients from our unit. Dialysis sessions performed in the ICUs were not included. RESULTS: A total of 38 calls occurred over 307,553 sessions, corresponding to an incidence of 0.012%. In a multivariate logistic regression model, statistically significant predictors to have a call for CPR were ischaemic heart disease (OR 3.93; 95% CI 1.70-9.07), heart failure (OR 2.74; 95% CI 1.12-6.74) and female gender (OR 2.96; 95% CI 1.37-6.43). Patients who had a call for CPR had a lower dialysis vintage than control patients (OR 0.98; 95% CI 0.965-0.996). Twenty of the 38 events presented on Mondays or Tuesdays (P = 0.012); 78% occurred during haemodialysis, vs 14 and 8% immediately after and immediately before dialysis but still on the unit, respectively. Of the 38 events, 24 were true cardiopulmonary arrests. Cardiac etiology was the most frequent (34%) and only 4 events were attributed to potassium disorders. One quarter of patients were dialyzed against a dialysate potassium concentration of 1 mmol/l or below. An arrhythmia was identified in 19 patients; a malignant ventricular fibrillation or ventricular tachycardia was most frequently found (32%), followed by severe bradycardia (26%). For the whole group, there were 6 deaths (16%) within 48 h; 30 patients (79%) were alive at 30 days and discharged from the hospital. Among the 24 cardiopulmonary arrests, there were 4 deaths (17%) within 48 h; 18 patients (75%) were alive at 30 days and discharged from the hospital. There was a trend for worse prognosis at 60 days when related to cardiopulmonary etiology (P = 0.054) and when a true cardiopulmonary arrest occurred (P = 0.134). CONCLUSIONS: This study confirms that arrest codes occur more frequently on Mondays and Tuesdays in a haemodialysis unit. Survival after an arrest code appears to be better than in certain other circumstances, probably in part because of the presence of witness, physician and equipment, and vascular access being readily available.