title: Activation of the renin-angiotensin system contributes significantly to the pathophysiology of oliguria in patients undergoing posterior spinal fusion.
abstract: OBJECTIVE
  This study was undertaken to investigate the role played by antidiuretic hormone (ADH), the renin-angiotensin system and atrial natriuretic factor (ANF) in the oliguria in patients undergoing spinal fusion.
  
  
  METHODS
  Sixteen patients undergoing posterior spinal fusion using isoflurane and fentanyl (n = 8) or sufentanil (n = 8) had renin, aldosterone, ADH and ANF measurements.
  
  
  RESULTS
  Compared to the non-oliguric patients, the oliguric patients had a higher number of fused vertebrae 10.5 +/- 1.3 vs. 9.0 +/- 0.5 (P = 0.01) and higher renin values at 12h (3.3 +/- 3.2 vs. 0.7 +/- 0.6 ng L(-1) s(-1), P = 0.04). Hormonal values that had a significant correlation with intraoperative diuresis were: renin at 0.5 h (r2 = 0.26, P = 0.04), aldosterone at 0.5 h (r2 = 0.30, P = 0.03) and ANF at 0.5 h (r2 = 0.32, P = 0.02). Those that had a significant correlation with the mean postoperative diuresis were: renin at 6 h (r2 = 0.29, P = 0.03), 8h (r2 = 0.26, P = 0.04) and 12h (r2 = 0.31, P = 0.03), aldosterone at 6h (r2 = 0.54, P = 0.001), 8h (r2 = 0.40, P = 0.01) and 12h (r2 = 0.32, P = 0.03), ADH at 24h (r2 = 0.38, P = 0.01) and ANF at 6h (r2 = 0.26, P = 0.045). Using stepwise regression, excluding hormonal values, only two continuous variables had a significant correlation with the mean postoperative diuresis: the number of fused vertebrae (P = 0.02) and the length of surgery (P = 0.02).
  
  
  CONCLUSIONS
  Activation of the renin-angiotensin system is the major cause of the early intraoperative oliguria. ADH and the renin-angiotensin system are both involved in the pathophysiology of postoperative oliguria in patients undergoing spinal fusion.
authors.affiliation: Maisonneuve-Rosemont Hospital, Department of Anaesthesiology, University of Montreal, Montreal, Quebec, Canada. joanne.guay@umontreal.ca
authors.forename: J
authors.initials: J
authors.lastname: Guay
authors.forename: L
authors.initials: L
authors.lastname: Lortie
mesh_terms: D000293:Adolescent; D000450:Aldosterone / Q000097:blood; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D009320:Atrial Natriuretic Factor / Q000097:blood / Q000502:physiology*; D005260:Female; D005283:Fentanyl; D006801:Humans; D007530:Isoflurane; D008297:Male; D009846:Oliguria / Q000209:etiology / Q000503:physiopathology*; D012083:Renin / Q000097:blood; D012084:Renin-Angiotensin System / Q000502:physiology*; D012600:Scoliosis / Q000601:surgery; D013123:Spinal Fusion / Q000009:adverse effects*; D017409:Sufentanil; D014667:Vasopressins / Q000097:blood
chemical_list: D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D014667:Vasopressins; D000450:Aldosterone; D009320:Atrial Natriuretic Factor; D017409:Sufentanil; D007530:Isoflurane; D012083:Renin; D005283:Fentanyl