Effect of lung resection on pleuro-pulmonary mechanics and fluid balance

Highlights

• We evaluated in patients the effect of lung resection on pleuro-pulmonary mechanics and fluid balance.

• The decrease in lung compliance following resection exceeded that expected from resected mass suggesting a perturbation in lung fluid balance.

• An inverse relationship was found between total pleural fluid drained and the decrease in lung compliance.

• We hypothesized that lung overdistension on re-expansion in the chest is causative to a perturbation in the pleuro-pulmonary fluid balance.

Abstract

The aim of the study was to determine in human patients the effect of lung resection on lung compliance and on pleuro-pulmonary fluid balance. Pre and post-operative values of compliance were measured in anesthetized patients undergoing resection for lung cancer (N = 11) through double-lumen bronchial intubation. Lung compliance was measured for 10–12 cm H₂O increase in alveolar pressure from 5 cm H₂O PEEP in control and repeated after resection. No air leak was assessed and pleural fluid was collected during hospital stay. A significant negative correlation (r² = 0.68) was found between compliance at 10 min and resected mass. Based on the pre-operative estimated lung weight, the decrease in compliance following lung resection exceeded by 10–15% that expected from resected mass. Significant negative relationships were found by relating pleural fluid drainage flow to the remaining lung mass and to post-operative lung compliance. Following lung re-expansion, data suggest a causative relationship between the decrease in compliance and the perturbation in pleuro-pulmonary fluid balance.

Introduction

A recent study (Miserocchi et al., 2010) described a model of perturbation of lung–chest wall mechanical coupling following lung resection based on the amount of resected mass as well as the preoperative lung mechanical properties. The study proposed to measure lung compliance in order to estimate the degree of lung hyperinflation when attempting to fit the resected lung to the chest. The hypothesis was put forward that hyperinflation of the resected lung might be a causative factor of postoperative pulmonary complications that include hydrothorax, lung edema and air leak. Following this line, an experimental animal model was developed to evaluate the decrease in lung compliance after lung resection aiming to relate it to the amount of resected mass as well as to an experimental hydrothorax of various entity (Salito et al., 2014a). Data from this study confirmed that comparing post-operative to the pre-operative lung compliance values provides a useful indication of the potential degree of hyperinflation following lung re-expansion in the chest. In fact, on occasion, the decrease in lung compliance following lung resection exceeded that expected based on resected mass, suggesting some perturbance affecting either the number of alveolar units available for lung ventilation and/or the elastic properties of the operated lung. The aim of the present study was to evaluate in human patients the effect of lung resection on pleuro-pulmonary mechanics and pleural fluid balance.