Pulmonary administration of prostacyclin (PGI2) during partial liquid ventilation in an oleic acid-induced lung injury: inhalation of aerosol or intratracheal instillation?
OBJECTIVE
The purpose of this study was to investigate the effects of aerosolized prostacyclin (A-PGI2) and intratracheally instilled prostacyclin (I-PGI2) during partial liquid ventilation (PLV) on gas exchange and pulmonary circulation in rabbits with acute respiratory distress.


METHODS
Prospective control study.


METHODS
A research laboratory at a university medical centre.


METHODS
Sixty-nine Japanese white rabbits.


METHODS
Lung injury was induced by oleic acid and the animals were divided into five groups of ten each: a mechanical gas ventilation (GV) group, an A-PGI2 group, a PLV group, an A-PGI2+PLV group and an I-PGI2+PLV group. PLV, A-PGI2+PLV and I-PGI2+PLV groups received 15 ml/ kg perflubron intratracheally while receiving mechanical GV. A-PGI2 and A-PGI2+PLV groups received aerosolized PGI2 (50 ng/kg/min) in combination with GV or PLV, respectively. The I-PGI2+PLV group was instilled 50 ng/kg/min PGI2 intratracheally in combination with PLV.


RESULTS
After lung injury, all animals developed hypoxia, hypercarbia and pulmonary hypertension. The improvement of partial pressure of arterial oxygen (PaO2) in the A-PGI2 and PLV groups was transient, whereas the A-PGI2+PLV and I-PGI2+PLV groups showed consistent improvement throughout the experiment. The PaO2 values of the I-PGI2+PLV group were significantly higher than those of the other groups 120 min after treatment. The mean pulmonary artery pressure (PAP) significantly decreased after treatment in the A-PGI2, APGI2+PLV and I-PGI2+PLV groups.


CONCLUSIONS
The results suggest that both aerosolized and intratracheally instilled PGI2 improve oxygenation and reduce PAP during PLV in oleic acid lung injury.
Department of Anaesthesiology and Critical Care Medicine, Tokyo Medical and Dental University School of Medicine, Japan. nakazawa.mane@tmd.ac.jp
K
K
Nakazawa
K
K
Yokoyama
Y
Y
Matsuzawa
K
K
Makita
K
K
Amaha
D000280:Administration, Inhalation; D000336:Aerosols; D000704:Analysis of Variance; D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage*; D001794:Blood Pressure / Q000187:drug effects; D011464:Epoprostenol / Q000008:administration & dosage*; D005260:Female; D005466:Fluorocarbons / Q000627:therapeutic use; D006439:Hemodynamics / Q000187:drug effects; D006976:Hypertension, Pulmonary / Q000188:drug therapy; D007322:Instillation, Drug; D021061:Liquid Ventilation; D008297:Male; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange / Q000187:drug effects; D011817:Rabbits; D012128:Respiratory Distress Syndrome / Q000188:drug therapy*; D015656:Respiratory Mechanics / Q000187:drug effects; D014132:Trachea
D000336:Aerosols; D000959:Antihypertensive Agents; D005466:Fluorocarbons; D011464:Epoprostenol