The effects of sternotomy and thoracotomy on respiratory muscle strength

Aim of the study: In this prospective clinical study; the effects of sternotomy and thoracotomy on respiratory muscle strength (RMS) were investigated.Material and methods: After Ethics Committee approval, 60 cases undergoing open heart surgery under sternotomy (Sternotomy Group [SG], n=30) and undergoing lung surgery under thoracotomy (Thoracotomy Group [TG], n=30) were enrolled. The values of pulmonary function (PF), (FEV1, FVC) and RMS (Pİmax, SNIP, PEmax) were obtained preoperatively and 3rd postoperative day. Fisher exact, x2, t, Mann-Whitney U and Wilcoxon Signed Ranks tests were used for statistical analysis. Data were given as mean±SD or (%), p<0.05 was considered significant.Results: The demographics, preanesthetic characteristics except ASA classification (p=0.02) and preoperative values of PF and RMS did not differ significantly between groups (p>0.05). The values of FEV1 (p=0.00, p=0.00, respectively), FVC (p=0.00, p=0.00, respectively), Pİmax (p=0.00, p=0.00, respectively), SNIP (p=0.00, p=0.00, respectively) and PEmax (p=0.00, p=0.00, respectively) decreased postoperatively both in SG and TG. The value of FVC was significantly lower in SG (1.54±0.56 L) compared to TG (1.87±0.56 L) at the 3rd postoperative day (p=0.021). Surgical procedure caused more decreases in the percentages of FVC (%48 vs %34, p= 0.04) and Pİmax (%38 vs %32, p=0.04) in SG than those of TG.Conclusion: In this study, sternotomy and thoracotomy caused significant reductions both in PF and RMS. Additionally, sternotomy affected FVC and Pİmax more than thoracotomy during the early postperative period.Key words: Sternotomy, thoracotomy, pulmonary function tests, respiratory muscle strength tests.