慢性阻塞性肺疾病患者吸气肌肌力与肺通气功能相关性分析

Correlation between inspiratory muscle strength and pulmonary ventilation function in patients with chronic obstructive pulmonary disease

目的分析慢性阻塞性肺疾病(COPD)患者吸气肌肌力情况及其与肺通气功能的相关性,判断能否用吸气肌肌力评估肺通气功能检查。方法回顾性分析2018年1月至2018年9月在中南大学湘雅二医院呼吸与危重症医学科住院的41例COPD患者。用POWER breathe K-5测试仪测试患者吸气肌肌力(MIP)、吸气峰流速(PIF)。计算出MIP占预计值百分比。用肺功能仪测定用力肺活量(FVC)、第1秒用力呼气量占预计值百分比(FEV1%)、FEV1占FVC的百分比(FEV1/FVC%)、呼气峰流速(PEF)、50%肺活量时的用力呼气流速占预计值百分比(FEF50%)、75%肺活量时的用力呼气流速占预计值百分比(FEF75%)。按COPD患者GOLD分级法将对应的患者MIP值、PIF值分成4组,组间比较。用Pearson相关性分析上述MIP测试值与肺通气功能测试值的相关性,有相关性的绘制散点图。结果 41例患者中39例(95. 1%)患者存在MIP下降。按GOLD肺功能分级,不同分级组间MIP比较差异有统计学意义(P <0. 05),其中Ⅲ级MIP[(47. 09±29. 42) cm H_2O]高于Ⅳ级[(24. 72±7. 66)cm H_2O],差异有统计学意义(P <0. 05),其余各组两两比较,差异均无统计学意义(P> 0. 05)。4组不同分级间PIF均值及两两比较,差异无统计学意义(P> 0. 05)。MIP与FVC呈中等程度正相关(P <0. 05),MIP与FEV1%、FEV1/FVC%、PEF、FEF50%、FEF75%无相关性(P> 0. 05)。MIP占预计值百分比与FVC、FEV1%呈弱正相关(P <0. 05),MIP占预计值百分比与FEV1/FVC%、PEF、FEF50%、FEF75%无相关性(P> 0. 05)。PIF与FVC、PEF、FEF50%、FEF75%呈弱正相关(P <0. 05),PIF与FEV1%、FEV1/FVC%无相关性(P> 0. 05)。结论 COPD患者普遍存在吸气肌功能障碍。不同GOLD肺功能分级患者,其MIP存在一定差异。MIP和肺通气功能部分值弱-中度相关,部分值不相关。因此不能很好地反映气道阻力的变化,不能替代肺通气功能。

Objective To analyze the correlation between inspiratory muscle strength and pulmonary ventilation function in chronic obstructive pulmonary disease (COPD) patients.Methods A total of 41 COPD patients admitted in the Second Xiangya Hospital from January to September 2018 were screened. The inspiratory muscle strength (MIP) and peak inspiratory flow (PIF) of patients were measured by using POWER breathe K-5 tester. The MIP was also calculated as a percentage of the predicted value. A pulmonary function detector was used to measure the forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1%), FEV1 as a percentage of FVC (FEV1/FVC%), peak expiratory flow (PEF), forced expiratory flow as a percentage of the predicted value (FEF 50%) at 50% of vital capacity and forced ex-piratory flow rate as a percentage of the predicted value (FEF 75%) at 75% of vital capacity. According to the Gobal Inistiative for chronic Obstructive Lung Disease (GOLD) classification method of COPD patients, the corresponding MIP value and PIF value of the patients were divided into 4 groups and conducted the comparison between groups. Pearson correlation was used to analyze the correlation between the above-mentioned inspiratory muscle strength test values and lung ventilation function test values, and a scatter diagram was drawn for the ones that had a correlation.Results Among the 41 patients, 39(95.1%) had a decrease in inspiratory muscle strength. According to the GOLD classification, the mean MIP value has a difference among the 4 groups. The mean MIP of grade Ⅲ was [(47.09±29.42)cmH2O], which was higher than that of grade Ⅳ of [(24.72±7.66)cmH2O] (P<0.05). There was no difference between PIF. The MIP was positively correlated with FVC (P<0.05). There was no correlation between MIP and FEV1%, FEV1/FVC%, PEF, FEF50% and FEF75% (P>0.05). The MIP as a percentage of the predicted value had a weak positive correlation with FVC and FEV1% (P<0.05). There was no significant correlation between MIP as a percentage of the predicted value and FEV1/FVC%, PEF, FEF50% and FEF75% (P>0.05). PIF had a weak positive correlation with FVC, PEF, FEF50% and FEF75%, with statistically significant difference (P<0.05). There was no significant correlation between PIF and FEV1% and FEV1/FVC% (P>0.05).Conclusions Inspiratory muscle dysfunction was common in patients with COPD. There was a difference in MIP among different GOLD lung function classification in COPD patients. Some values of the inspiratory muscle strength and lung ventilation function had a weak-moderate correlation, while some values had no correlation. Therefore, inspiratory muscle strength test cannot replace the lung ventilation function test in COPD patients.