Sodium nitroprusside and positive end-expiratory pressure are not detrimental in canine asymmetric pulmonary edema.
The effects of PEEP and subsequent augmentation of cardiac output by sodium nitroprusside (SNP) were examined in a canine model of asymmetric oleic acid injury to the right lung. PEEP (9.2 +/- 0.5 cm H2O) was added to six animals to decrease venous admixture (Qsp/Qt) from 50.6 +/- 4.4% to 16.0 +/- 1.3% (p less than .05). With PEEP, intrapulmonary blood flow distribution (assessed by radioactive microspheres) decreased significantly to nondependent lung regions while increasing to dependent regions. In six other animals, zero end-expiratory pressure (ZEEP) did not alter intrapulmonary blood flow distribution. SNP was then administered to increase cardiac output by 40% (to 2.60 +/- 0.21 L/min in the ZEEP group and to 1.75 +/- 0.27 L/min in the PEEP group). SNP produced no adverse effects on Qsp/Qt or intrapulmonary blood flow distribution. Specifically, SNP did not preferentially dilate pulmonary vessels injured by oleic acid with or without end-expiratory pressure. Thus, administration of a vasodilator drug in asymmetric pulmonary edema appears well tolerated.
Johnston
W E
WE
Department of Anesthesia, Bowman Gray School of Medicine, Winston-Salem, NC 27103.
Vinten-Johansen
J
J
Tommasi
E
E
D000818:Animals; D001794:Blood Pressure; D002302:Cardiac Output / Q000187:drug effects*; D002405:Catheterization, Central Venous; D004285:Dogs; D005292:Ferricyanides / Q000627:therapeutic use*; D006339:Heart Rate; D008168:Lung / Q000098:blood supply; D009599:Nitroprusside / Q000627:therapeutic use*; D010100:Oxygen / Q000097:blood; D011175:Positive-Pressure Respiration; D011654:Pulmonary Edema / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy*; D012039:Regional Blood Flow; D012121:Respiration, Artificial
D005292:Ferricyanides; D009599:Nitroprusside; D010100:Oxygen