Effects of sodium nitroprusside on splanchnic microcirculation in a resuscitated porcine model of septic shock.
BACKGROUND
We tested the hypothesis that sodium nitroprusside (SNP) might improve the impairment of hepatosplanchnic microcirculatory blood flow (MBF) in septic shock.


METHODS
Fourteen pigs were anaesthetized and their lungs mechanically ventilated. Sepsis was induced with i.v. infusion of live Pseudomonas aeruginosa [1x10(8) colony forming units (CFU) ml(-1) kg(-1)] for 1 h. Sixty minutes later, the animals received in a random succession either SNP or normal saline for 30 min. Mean arterial pressure (MAP), cardiac index (CI), mean pulmonary artery pressure (MPAP), carbon dioxide tension of the ileal mucosa (PCO2; by gas tonometry), ileal mucosal and hepatic MBF by laser Doppler flowmetry, blood gases, and lactates were assessed before, during administration, and 30 min after discontinuing the test drug.


RESULTS
Bacterial infusion promoted hypodynamic shock (MAP -18%, CI -33%, ileal MBF -19%, and hepatic MBF -27%), which was converted to normodynamic shock by resuscitation. During SNP infusion, ileal mucosal MBF significantly increased (+19%) compared with control (P = 0.033). Although hepatic MBF increased (+42% from baseline), this did not differ from control. In order to maintain a constant central venous pressure and MAP, fluid loading and norepinephrine (P < 0.01) were increased. Acid-base status was not altered by SNP.


CONCLUSIONS
In a resuscitated porcine model of the early phase of septic shock, SNP improved ileal mucosal MBF but required a concomitant increase in fluid and norepinephrine supplements to maintain constant systemic haemodynamic parameters.
Assadi
A
A
Department of Anaesthesia, Edouard Herriot Hospital, 5, Place Arsonval, 69437 Lyon cedex 03, France. assadinasser@yahoo.com
Desebbe
O
O
Kaminski
C
C
Rimmelé
T
T
Bénatir
F
F
Goudable
J
J
Chassard
D
D
Allaouchiche
B
B
D000136:Acid-Base Equilibrium / Q000187:drug effects; D000818:Animals; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical / Q000379:methods; D005260:Female; D007082:Ileum / Q000098:blood supply; D007413:Intestinal Mucosa / Q000098:blood supply; D008102:Liver Circulation / Q000187:drug effects; D008833:Microcirculation / Q000187:drug effects; D009599:Nitroprusside / Q000494:pharmacology*; D012039:Regional Blood Flow / Q000187:drug effects; D012121:Respiration, Artificial; D012772:Shock, Septic / Q000503:physiopathology* / Q000628:therapy; D013152:Splanchnic Circulation / Q000187:drug effects*; D034421:Sus scrofa; D014665:Vasodilator Agents / Q000494:pharmacology*
D014665:Vasodilator Agents; D009599:Nitroprusside