Measurement of Lung Microvascular Pressure in the Intact Anesthetized Rabbit by the Micropuncture Technique

• Published in: Circulation research 1989-01, Vol.64 (1), p.167-172
• Main Authors: Bhattacharya, Sunita, Glucksberg, Matthew R, Bhattacharya, Jahar
• Format: Article
• Language: English
• Subjects: Anesthesia; Animals; Biological and medical sciences; Blood Pressure; Blood Pressure Determination - methods; Capillaries; Fundamental and applied biological sciences. Psychology; Hemodynamics. Rheology; Pulmonary Circulation; Rabbits; Vertebrates: cardiovascular system
• ISSN: 0009-7330; 1524-4571
• DOI: 10.1161/01.res.64.1.167

We have developed a micropuncture technique for the measurement of microvascular pressure in the intact lung of rabbit. We anesthetized 16 rabbits (halothane, 0.8%) and mechanically ventilated them through a tracheotomy. Then, we exposed the right lung by rib resection over the right anterior chest. We measured pulmonary artery, left a trial, and systemic pressures by direct catheterization and cardiac output by the thermodilution technique. For micropuncture, we stabilized the lung on a shelf and stopped ventilation for 3-4 minutes at an airway pressure of 7 cm H2O. We injected pancuronium intravenously to paralyze the diaphragm and intercostal muscles. Of the total pulmonary vascular pressure drop, 52% occurred in the microvascular segment between arterioles and venules of 20 μm diameter, 28% occurred in the arterial segment, and 20% occurred in the venous segment. We conclude that in the intact lung of rabbit, the major pressure drop occurs in the microvascular segment.