Criner Rachel N, Yu Daohai, Jacobs Michael R, Criner Gerard J
Department of Internal Medicine, University of Michigan, Ann Arbor.
Department of Clinical Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania.
Chronic Obstr Pulm Dis. 2018 Oct 12;6(1):40-50. doi: 10.15326/jcopdf.6.1.2018.0188.
Long-term effects of lung volume reduction surgery (LVRS) on respiratory muscle strength and effects of age, sex, and emphysema pattern on these changes are unknown. Therefore, we aimed to determine the long-term effect of LVRS on respiratory muscle strength changes in severe emphysema. The National Emphysema Treatment Trial was a prospective controlled multicentered trial, comparing LVRS to optimal medical treatment on survival and maximal exercise capacity. We examined percentage change in maximum inspiratory pressure (MIP) from baseline to 36 months follow-up to determine impact of LVRS as well as age, sex, emphysema pattern and exercise capacity on changes in MIP compared to medical treatment. LVRS individuals had significantly greater increases in MIP from baseline compared to medical individuals at all follow-ups (LVRS 19.8 ± 42.3%, medical 3.2 ± 29.3%, <0.0001, 12 months). The LVRS group had significant decreases in total lung capacity (TLC), residual volume (RV), functional residual capacity (FRC) and RV/TLC compared to the medical arm at all follow-up periods. Males and individuals 65-70 years of age had significantly greater increases in MIP following LVRS compared to the medical arm at all follow-ups; this same relationship was seen at up to 24 months for low exercise capacity, upper lobe predominant emphysema. LVRS significantly increases inspiratory muscle strength up to 3 years post-operatively, with male sex, age 65-70 years and low exercise capacity, upper lobe predominant emphysema especially associated with increased MIP. Inspiratory muscle strength increases were associated with decreases in non-invasive markers of dynamic hyperinflation, suggesting that LVRS allows inspiratory muscles to return to their optimal length-tension relationship.
肺减容手术（LVRS）对呼吸肌力量的长期影响以及年龄、性别和肺气肿类型对这些变化的影响尚不清楚。因此，我们旨在确定LVRS对严重肺气肿患者呼吸肌力量变化的长期影响。国家肺气肿治疗试验是一项前瞻性对照多中心试验，比较了LVRS与最佳药物治疗对生存率和最大运动能力的影响。我们检查了从基线到36个月随访期间最大吸气压力（MIP）的百分比变化，以确定LVRS以及年龄、性别、肺气肿类型和运动能力对与药物治疗相比MIP变化的影响。与接受药物治疗的个体相比，接受LVRS治疗的个体在所有随访中MIP从基线的增加均显著更大（LVRS为19.8±42.3%，药物治疗为3.2±29.3%，<0.0001，12个月）。与药物治疗组相比，LVRS组在所有随访期间的总肺容量（TLC）、残气量（RV）、功能残气量（FRC）和RV/TLC均显著降低。在所有随访中，男性以及65 - 70岁的个体在接受LVRS治疗后MIP的增加显著大于接受药物治疗的个体；对于低运动能力、上叶为主型肺气肿，在长达24个月时也观察到了相同的关系。LVRS在术后3年内显著增加吸气肌力量，男性、65 - 70岁以及低运动能力、上叶为主型肺气肿尤其与MIP增加相关。吸气肌力量的增加与动态肺过度充气的非侵入性指标降低相关，这表明LVRS使吸气肌能够恢复到其最佳长度 - 张力关系。
