title: Inhaled amyl nitrite effectively reverses acute catastrophic thromboxane-mediated pulmonary hypertension in pigs.
abstract: Acute catastrophic pulmonary vasoconstriction frequently leads to cardiovascular collapse. Rapid and selective pulmonary vasodilation is desired in order to restore haemodynamic stability. This pilot study examined the effectiveness of inhaled amyl nitrite as a selective pulmonary vasodilator. Nine adult swine were anaesthetized. Acute pulmonary hypertension with haemodynamic collapse was induced with a bolus administration of a thromboxane analogue, U46619. Six animals then received a capsule of amyl nitrite. The administration of inhaled amyl nitrite decreased mean pulmonary artery pressure from 42 +/- 3 to 22 +/ 3 mmHg at five minutes (p < 0.05), with a concomitant increase in cardiac output and mean arterial pressure. Pulmonary vascular resistance decreased from 4889 +/- 1338 to 380 +/- 195 dyne. sec. cm(-5) (by 92% from the maximal pulmonary hypertension change), with significant improvement in systemic haemodynamics. During acute thromboxane-mediated pulmonary hypertension with cardiovascular collapse, prompt administration of inhaled amyl nitrite was effective in restoring pulmonary and systemic haemodynamics within five minutes.
authors.affiliation: Department of Anesthesiology, University of Florida College of Medicine and Anesthesia Service, Malcom Randall Veterans Administration Medical Center, Gainesville, Florida 32610-0254, USA.
authors.forename: Jochen D
authors.initials: JD
authors.lastname: Muehlschlegel
authors.forename: Emilio B
authors.initials: EB
authors.lastname: Lobato
authors.forename: David S
authors.initials: DS
authors.lastname: Kirby
authors.forename: G
authors.initials: G
authors.lastname: Arnaoutakis
authors.forename: Anver
authors.initials: A
authors.lastname: Sidi
mesh_terms: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D000208:Acute Disease; D000280:Administration, Inhalation; D000680:Amyl Nitrite / Q000008:administration & dosage / Q000627:therapeutic use*; D000818:Animals; D004195:Disease Models, Animal; D006976:Hypertension, Pulmonary / Q000139:chemically induced / Q000188:drug therapy*; D010865:Pilot Projects; D011652:Pulmonary Circulation / Q000187:drug effects; D013552:Swine; D014661:Vasoconstriction / Q000187:drug effects*; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D000680:Amyl Nitrite