Revised resuscitation guidelines: adrenaline versus adrenaline/vasopressin in a pig model of cardiopulmonary resuscitation--a randomised, controlled trial

BACKGROUND: Synergistic effects of adrenaline (epinephrine) and vasopressin may be beneficial during cardiopulmonary resuscitation. However, it is unknown whether either adrenaline alone or an alternating administration of adrenaline and vasopressin is better for restoring vital organ perfusion following basic life support (BLS) according to the revised algorithm with a compression-to-ventilation (c/v) ratio of 30:2. MATERIAL AND METHODS: After 4min of ventricular fibrillation, and 6min of BLS with a c/v ratio of 30:2, 16 pigs were randomised to receive either 45microg/kg adrenaline, or alternating 45microg/kg adrenaline and 0.4U/kg vasopressin, respectively. RESULTS: Coronary perfusion pressure (mean+/-S.D.) 20 and 25min after cardiac arrest was 7+/-4 and 5+/-3mm Hg after adrenaline, and 25+/-2 and 14+/-3mm Hg after adrenaline/vasopressin (p<0.001 and <0.01 versus adrenaline), respectively. Cerebral perfusion pressure was 23+/-7 and 19+/-9mm Hg after adrenaline, and 40+/-10 and 33+/-7mm Hg after adrenaline/vasopressin (p<0.001 and <0.01 versus adrenaline), and cerebral blood flow was 30+/-10 and 27+/-11% of baseline after adrenaline, and 65+/-40 and 50+/-31% of baseline after adrenaline/vasopressin (p<0.05 versus adrenaline), respectively. Return of spontaneous circulation (ROSC) did not differ significantly between the adrenaline group (0/8) and the adrenaline/vasopressin group (3/8). CONCLUSION: Adrenaline/vasopressin resulted in higher coronary and cerebral perfusion pressures, and cerebral blood flow, while ROSC was comparable.