American Board of Surgery In-Training Examination (ABSITE) Practice Exam

In assessing candidates for lung resection, particularly in patients with underlying pulmonary conditions, evaluating carbon dioxide levels is crucial. The preoperative resting pCO2 levels provide insights into the patient's respiratory function and ability to tolerate the physiological demands post-surgery.

A resting pCO2 greater than 50 mmHg typically indicates significant respiratory insufficiency. At this level, patients may struggle to maintain adequate gas exchange, which is essential for recovery postoperatively. Elevated pCO2 can signal hypoventilation or an inability to adequately oxygenate the blood, increasing the risk of complications such as respiratory failure after resection.

Therefore, a pCO2 level exceeding 50 mmHg becomes a vital contraindication for lung resection procedures. It suggests that the patient would likely not cope well with the increased demands on their respiratory system that would follow a significant surgical intervention. The presence of such elevated pCO2 levels indicates that the lungs may not effectively handle the stress post-resection, warranting a careful evaluation of the risks involved before proceeding with surgery.