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.
Nakazawa
K
K
Department of Anaesthesiology and Critical Care Medicine, Tokyo Medical and Dental University School of Medicine, Japan. nakazawa.mane@tmd.ac.jp
Yokoyama
K
K
Matsuzawa
Y
Y
Makita
K
K
Amaha
K
K
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