title: Early adrenaline administration does not improve circulatory recovery during resuscitation from severe asphyxia in newborn piglets.
abstract: OBJECTIVE
  To investigate the effects of early intravenous adrenaline administration on circulatory recovery, cerebral reoxygenation, and plasma catecholamine concentrations, after severe asphyxia-induced bradycardia and hypotension.
  
  
  METHODS
  One-day-old piglets were left in apnoea until heart rate and mean arterial pressure were less than 50 min(-1) and 25 mmHg, respectively. They randomly received adrenaline, 10 μgkg(-1) (n=16) or placebo (n=15) and were resuscitated with air ventilation and, when needed, closed-chest cardiac massage (CCCM). Eight not asphyxiated animals served as time controls.
  
  
  RESULTS
  CCCM was required in 13 piglets given adrenaline and in 13 given placebo. Time to return of spontaneous circulation was: 72 (66-85)s vs. 77 (64-178)s [median (quartile range)] (p=0.35). Time until cerebral regional oxygen saturation (CrSO(2)) had increased to 30% was 86 (79-152)s vs. 126 (88-309)s (p=0.30). The two groups did not differ significantly in CrSO(2), heart rate, arterial pressure, right common carotid artery blood flow, or number of survivors: 13 vs. 11 animals. Plasma concentration of adrenaline, 2.5 min after resuming ventilation, was 498 (268-868)nmoll(-1) vs. 114 (80-306)nmoll(-1) (p=0.01). Corresponding noradrenaline concentrations were 1799 (1058-4182)nmoll(-1)vs. 1385 (696-3118)nmoll(-1) (ns). In the time controls, the concentrations were 0.4 (0.2-0.6)nmoll(-1) of adrenaline and 1.8 (1.3-2.4)nmoll(-1) of noradrenaline.
  
  
  CONCLUSIONS
  The high endogenous catecholamine levels, especially those of noradrenaline, may explain why early administered adrenaline did not significantly improve resuscitation outcome.
authors.affiliation: Department of Cardiothoracic Anaesthesia and Intensive Care, Skåne University Hospital, Lund University, Lund SE-22185, Sweden. Rikard.Linner@googlemail.com
authors.forename: Rikard
authors.initials: R
authors.lastname: Linner
authors.forename: Olof
authors.initials: O
authors.lastname: Werner
authors.forename: Valeria
authors.initials: V
authors.lastname: Perez-de-Sa
authors.forename: Doris
authors.initials: D
authors.lastname: Cunha-Goncalves
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001775:Blood Circulation / Q000187:drug effects*; D016887:Cardiopulmonary Resuscitation; D004837:Epinephrine / Q000008:administration & dosage* / Q000627:therapeutic use; D013552:Swine; D017211:Treatment Failure
chemical_list: D004837:Epinephrine