Influence of an artificial pleural effusion technique on cardio-pulmonary function and autonomic activity

Percutaneous treatment of hepatocellular carcinoma (HCC) located directly under the diaphragm is problematic because ultrasonic imaging is difficult, and the lung may be injured during the procedure. It has been reported that an infusion of 5% glucose solution into the thoracic cavity enables percutaneous treatment in such cases. However, the safety aspects of this have not been investigated. In this study, variations in heart rate and changes in circulatory and respiratory dynamics were examined during the infusion of artificial pleural effusion directly under the diaphragm in patients with HCC.

The subjects were 13 patients with an HCC directly under the diaphragm. About 500 ml of a 5% glucose solution was infused into the thoracic cavity, and mean blood pressure, heart rate, and oxygen saturation were measured. Holter electrocardiography was simultaneously recorded to evaluate autonomic nerve function. To analyze variations in heart rate, the low-frequency waves (LF: 0.04-0.15 Hz), high-frequency waves (HF: 0.15-0.40 Hz, an index of parasympathetic nerve activity), and the LF/HF ratio (index of sympathetic nerve activity) were examined. The above parameters were measured before, during (when infusion of the half the planned volume was complete), and after infusion were compared.

No significant changes in the mean blood pressure or heart rate were found. Oxygen saturation was significantly decreased during and after the infusion. The HF value was slightly higher after infusion and the LF value was significantly increased during infusion. The LF/HF ratio was significantly increased during infusion, and this increase persisted after infusion.

The infusion of artificial pleural effusion had no effect on circulatory dynamics, but transiently affected respiratory functions. It was also revealed that infusion stimulated the parasympathetic nerves.