Behavior of Pulmonary Function after Hospital Discharge in Patients Submitted to Myocardial Revascularization

Abstract Background: Coronary artery bypass grafting (CABG) is a type of surgery where there is a compromise in one or more coronary arteries, with the objective of restoring function to the areas that have been compromised in the heart, possibly leading to respiratory compromise and postoperative complications. The return time of the pulmonary function to the preoperative condition is still indeterminate in the literature. Objective: To describe the behavior of pulmonary function after hospital discharge in patients submitted to CABG. Methods: This is a prospective cohort study. Only patients undergoing MRI, whose lung function was evaluated preoperatively, at hospital discharge and 30 days after surgery, were evaluated. This evaluation consisted of maximum inspiratory pressure (MIP) and expiratory (MEP), vital capacity (VC) and expiratory flow peak (EFP). Results: A total of 30 patients were evaluated, of which 18 (60%) were males, mean age 62 ± 9 years. A reduction in lung function from preoperative time to hospital discharge was observed in all variables. There was improvement in MIP (88 ± 9 vs 109 ± 5, p < 0.001), MEP (67 ± 10 for 90 ± 8, p < 0.001) and EFP (310 ± 59 for 390 ± 32, p < 0.001), high for review. At the time of the review, no variables returned to their preoperative value: MIP (116 ± 5 for 109 ± 5, p = 0.43), MEP (111 ± 8 for 90 ± 8, p < 0.001), VC (45 ± 12 for 39 ± 7, p = 0.33) and EFP (430 ± 40 for 390 ± 32, p < 0.001). Conclusion: It is concluded that MRI surgery reduces lung function and is not reestablished after 30 days of the procedure. Being the expiratory muscular force and the peak of expiratory flow the most affected.

摘要 背景：冠状动脉旁路移植术（Coronary artery bypass grafting, CABG）是针对一条或多条冠状动脉狭窄的手术术式，旨在恢复心脏受损区域的血供与功能，该手术可能引发呼吸功能不全及术后并发症。目前学界对于肺功能恢复至术前水平的时间仍未明确。目的：描述接受CABG的患者出院后肺功能的变化特征。方法：本研究为前瞻性队列研究，仅纳入术前行肺功能评估、出院时及术后30天接受肺功能复测的患者，评估指标包括最大吸气压力（maximum inspiratory pressure, MIP）、最大呼气压力（maximum expiratory pressure, MEP）、肺活量（vital capacity, VC）及呼气峰流速（expiratory flow peak, EFP）。结果：共纳入30例患者，其中18例为男性（占比60%），平均年龄62±9岁。从术前至出院时，所有肺功能指标均出现下降。术后30天随访时，MIP（88±9 vs 109±5，p<0.001）、MEP（67±10 vs 90±8，p<0.001）及EFP（310±59 vs 390±32，p<0.001）均较出院时有所改善，且维持在较高水平；但此时所有指标均未恢复至术前水平：MIP（116±5 vs 109±5，p=0.43）、MEP（111±8 vs 90±8，p<0.001）、VC（45±12 vs 39±7，p=0.33）及EFP（430±40 vs 390±32，p<0.001）。结论：本研究结果提示，CABG手术会降低患者肺功能，且术后30天仍未恢复至术前水平，其中以呼气肌力量及呼气峰流速受影响最为显著。