Buffer therapy during out-of-hospital cardiopulmonary resuscitation

Abstract

The effects of infusing a buffer solution on resuscitability and outcome was tested in patients during out-of-hospital cardiac arrest. A number (502) of adults with asystole or ventricular fibrillation with failure of first defibrillation attempt were entered into a prospective, randomized, double-blind, controlled trial. Of these, 245 patients received 250 ml of a sodium bicarbonate-trometamol-phosphate mixture with buffering capacity 500 mmol/l and 257 patients received 250 ml 0.9% saline. Except for the investigational infusion, all patients were resuscitated according to international guidelines. Eighty-seven patients (36%) receiving buffer were admitted to hospital ICU and 24 (10%) were discharged from hospital alive, vs. 92 (36%) and 35 (14%) receiving saline (95% confidence interval (CI) for difference between groups; −6%–6% for rate of admission and −1%–9% for rate of discharge). Using a logistic regression analysis, ventricular fibrillation as initial rhythm (odds ratio 8.06, CI 3.70–17.56) improved the outcome, whereas buffer therapy had no effect (odds ratio 0.77, CI 0.43–1.41). Mean base excess at hospital admission was −9 after Tribonat vs. −11 after saline (P = 0.04, CI for difference 0.2–3.8), Only 16 of the 502 patients had arterial alkalosis on arrival in the hospital and no patient had a positive base excess. Patients resuscitated after out-of-hospital cardiac arrest had metabolic acidosis, but buffer therapy did not improve the outcome.