The relationship between respiratory-circulatory changes and pulmonary complications in elderly patients after thoracotomy / 中华胸心血管外科杂志

ABSTRACT

Objective To study the respiratory and circulatory changes in elderly patients, and their relationship with pulmonary complications after thoracotomy. Methods 58 elderly patients either aged over 75 years, with major organ dysfunction or underwent highly invasive procedures (group 1). Respiratory and circulatory status, including arterial blood gas under room air, water balance, urine gravity, and hemodynamics monitoring through pulmonary artery catheter were documented. The results were compared with those from 56 young patient controls receiving thoracotomy in the same period (group 2). Results All 12 patients having pulmonary complications were from group 1 (group 1A). Ten of them presented on the 2nd or 3rd postoperative day with hypoxemia. The other 2 died of type II respiratory failure after severe infection. Preoperative pulmonary co-morbidity (P=0.026, Exp(B)=5.4) and obesity (P=0.043, Exp(B)=4.9) were identified as independent risk factors for pulmonary complications after thoracotomy in elderly patients. During the first 3 postoperative days, PaO_2 of group 1A was significantly lower than group 2 as well as the other elderly patients who did not develop pulmonary complications after surgery (Group 1B). PaCO_2 of group 1A and 1B were significantly lower than group 2. There were also significant differences between the three groups in water balance on the first postoperative day (group 1A +832ml, P=0.006 vs. group 1B +109ml, P=0.004 vs. group 2 -243ml ). Urine gravity in group 1A was also significantly higher than in group 2 in the first 3 postoperative days. Pulmonary artery catheter monitoring revealed increased cardiac output and decreased systemic vascular resistance, showing a hyperdynamic status, in elderly patients after surgery. Pulmonary vascular resistance was elevated in the same time. Conclusion Pulmonary co-morbidities commonly seen in elderly patients are responsible for pulmonary complications, the major cause of surgical mortality after thoracotomy. Hypoxemia in the early postoperative period is mainlycaused by relative volume overloading from trauma induced interstitial edema. Close monitoring of arterial blood gas under room air, water balance, and urine gravity after thoracotomy may identify elderly patients at risk of developing pulmonary complication and prompt timely intervention.