Ventilation-perfusion relationships and central haemodynamics in patients with cirrhosis. Effects of a somatostatin analogue.

The ventilation-perfusion relationships of the lung (VA/Q) and central haemodynamics were studied in seven patients with cirrhosis before and 30 min after a bolus injection of a somatostatin analogue, octreotide (Sandostatin, 50 micrograms i.v.), to elucidate the role of this substance in the hepatopulmonary syndrome. In the basal state all patients had normal spirometry but reduced diffusing capacity. Three patients had various degrees of hypoxaemia (6.9-8.3 kPa) and three had clubbing of the fingers. In the basal state VA/Q distributions, determined by inert gas elimination technique, showed an intrapulmonary shunt of 7.9 +/- 2.2% of cardiac output (range 1.5 to 17.1) and perfusion of lung regions with "low VA/Q" of 4.4 +/- 2.2% of cardiac output (range 0 to 15.4). After octreotide, the amount of shunting increased (10.9 +/- 4.4% of cardiac output; non-significant), while "low VAQ" was unchanged (3.7 +/- 1.3% of cardiac output). Arterial oxygen tension decreased from 10.2 +/- 1.1 to 9.7 +/- 1.1 kPa (non-significant). The mean pulmonary arterial pressure increased from 14.5 +/- 1.9 to 16.3 +/- 1.8 mmHg (p < 0.01). No alterations were seen in heart rate, stroke volume, cardiac output, central pressures or vascular resistances. The results of the present study do not support the hypothesis that octreotide improves hypoxaemia and ventilation-perfusion relationships in patients with hepatopulmonary syndrome.