Dr. Tharp’s Research

Impaired Lung Mechanics and Intraoperative Ventilator Induced Lung Injury

Post-operative pulmonary complications are common, costly, and difficult to predict. Impaired intraoperative lung mechanics may lead to alveolar injuries arising from combinations of patient or procedural factors. The magnitude at which impaired lung mechanics leads to pathological damage is not known. Concerted clinical trial efforts at refining lung protective ventilation have yielded marginal improvement in patient outcomes. Human biological data on intraoperative lung injury are nearly absent.

Previously we found a high degree of impairment in lung mechanics during robotic assisted laparoscopic surgery. The data suggested regionally heterogenous ventilation and potential for atelectrauma. The impairment was increasingly severe in subjects with obesity, leading us to speculate about the potential for subclinical lung injury.

This integrated respiratory physiology study aims to determine the relationships between impaired lung mechanics, regional alveolar damage, and obesity. We will first collect blood and bronchoalveolar lavage before and after surgery and measure intraoperative pulmonary mechanics in a cross-sectional study. We will assay for markers of alveolarcapillary disruption and examine their association with lung mechanics and patient factors. We will then conduct a proof-of concept interventional trial, using transpulmonary pressure guided ventilation to improve intraoperative lung mechanics and look for changes in markers of alveolar-capillary damage in blood and bronchoalveolar lavage.

This research is designed to address important, unanswered questions about intraoperative ventilation, lung injury, and obesity. The data from this study will potentially provide biochemical targets and mechanical ventilation parameters useful in refining lung protective ventilation methods. The results will be relevant to a wide audience ranging from basic scientists to clinical anesthesiologists.