Objectives: To determine lung functional parameters of 117 patients with stable chronic obstructive pulmonary disease (COPD) at 103 Hospital from October, 2013 to March, 2016 by plethysmography and to study the relationship among these parameters with stages of stable COPD. Methods: A prospective and cross-descriptive study.
Journal of military pharmaco-medicine no7-2017 RESULTS OF LUNG FUNCTIONAL PARAMETERS MEASURED BY PLETHYSMOGRAPHY IN STABLE COPD Pham Thi Phuong Nam*; Dong Khac Hung*; Nguyen Huy Luc*** Summary Objectives: To determine lung functional parameters of 117 patients with stable chronic obstructive pulmonary disease (COPD) at 103 Hospital from October, 2013 to March, 2016 by plethysmography and to study the relationship among these parameters with stages of stable COPD Methods: A prospective and cross-descriptive study Results: A decrease in the pulmonary ventilatory indices, difusing capacity for carbon monoxide (DLCO) and the increase in airway resistance, distention pulmonary indices in patients with stable COPD were recorded In addition to FEV1 (forced expiratory volume) parameter, MVV (maximal voluntary ventilation), RV/TLC (residual volume/total lung capacity), raw (resistance air way), DLCO (diffusing capacity for carbon monoxide) parameters highly related with the severity of the disease (eta = 0.737; eta = 0.686; eta = 0.414, eta = 0.583), respectively with p < 0.05 Conclusions: There were variations of lung functional parameters and these variations related with the classification of the severity of COPD MVV, raw, RV/TLC are very important parameters in prognosis the severity of COPD * Keywords: Lung functional parameters; Chronic obstructive pulmonary disease; Plethysmography; Stable COPD INTRODUCTION Chronic obstructive pulmonary disease (COPD) is a respiratory disease with an increase in morbidity and mortality In 2012, there were about million deaths due to COPD, accounting for nearly 6% of the causes of death Particularly, in Vietnam, the incidence of disease is quite high (6.7%), which is the top of 12 countries in Southeast Asia [11] Pulmonary ventilation, static lung, resistance airway, diffusion of alveoli - capillaries explorations are very valuable in the complete evaluation of COPD, one of the three major components to evaluate the severity of COPD with clinical characteristics and comorbidity factors Whole body plethysmography is a modern equipment that allows for comprehensive and accurate parameters of respiratory functional exploration In Vietnam, the complete exploration is not widely applied for patients with COPD Therefore, the purpose of this research was to: Assess the result of lung functional parameters measured by plethysmography in stable COPD * Viettiep Hospital ** Vietnam Military Medical University *** 103 Military Hospital Corresponding author: Pham Phuong Thi Nam (ptpm@gmail.com) Date received: 20/07/2017 Date accepted: 21/08/2017 97 Journal of military pharmaco-medicine No7-2017 Classify the stages of stable COPD: groups A, B, C, D, GOLD 2016 [9] SUBJECTS AND METHODS Subjects 117 patients diagnosed with COPD (GOLD 2016) were treated at 103 Hospital from September, 2013 to the end of March, 2017, without contradication of respiratory fronctional exploration, after the exacerbation of COPD and volunteer to participate in research Methods * Study design: Prospective, crossdescriptive study * Sample size calculation: based on convenience * Data collection, data grouping, data classification: Age, gender, height, weight Evaluation for the effect of COPD on the health and patients’ daily life by score CAT (COPD Assessment Test) with questionnaires for each patients Lung functional parameters test for 117 patients was measured by whole body plethysmography: FVC, FEV1, MVV, RV, FRC, TLC, Raw, DLCO Diagnosis of COPD: Standard GOLD 2016 Determine the mean values of lung functional parameters, mean percentage of predicted value Predicted value was based on Knudson's 1983 standard for Asians - Material: The Care Fusion whole body plethysmography is daily calibrated for accuracy, stability, tolerability - Lung functional test: Patients were prepared at least 15 minutes before the test and not use stimulants Patients were measured for pulmonary ventilation, pulmonary static volume and resistance airway, in which 75 patients were measured for DLCO Take 5-minute measurement each and repeat this procedure three times The results are mean values of two best times which were different less than 10% * Statistical analysis: Statistical Program for Social Science (SPSS) version 16.0 The relation between parameters and severity classification were measured by Association of Anova Table The level of significance was set at p value of less than 0.05 RESULTS Characteristics of the study patients with stable COPD Table 1: Characteristics of patients (n = 117) Age (year) BMI 98 n % 50 - 59 23 19.7% 60 - 69 68 58.1% 70 - 80 26 22.2% BMI < 18.5 55 47% 18.5 ≤ BMI < 23 57 48.7% BMI ≥ 23 4.3% Journal of military pharmaco-medicine no7-2017 Genders Classification Male 114 97.4% Female 2.6% A 16 13.7% B 17 14.5% C 17 14.5% D 67 55.3% Table showed that the patients were over 50 years old and male represented predominantly (97.4%) There were a large proportion of malnutrition patients, 47% of the patients had BMI < 18 Patients in group D (high risks, multiple symptoms group) had the highest proportion (57.3%) Determination of parameters values in patients with COPD Table 2: Values of lung functional parameters of patients with COPD Lung functional parameters Pulmonary ventilation Pulmonary static Pulmonary mechanic n 117 117 117 Parameters (unit) mean ± SD % VC (lit) 2.36 ± 0.73 84.6 ± 24.8 FEV1 (lit) 1.19 ± 0.59 51.8 ± 23.9 MVV (lit) 44.3 ± 23.1 40.0 ± 19.8 TLC (lit) 6.45 ± 1.42 130.5 ± 26.1 FRC (lit) 4.74 ± 1.50 145.6 ± 42.0 RV (lit) 4.08 ± 1.55 207.2 ± 76.7 RV/TLC 0.62 ± 0.13 Raw (cmH2O/lit/second) DLCOadj Diffusing capacity for carbon monoxide 75 (mmolCO/min/mmHg) KCOadj (mmolCO/lmin/mmHg) 7.87 ± 4.2 570.0 ± 336.0 12.4 ± 11.2 77.8 ± 29.6 2.9 ± 0.9 77.6 ± 24.4 There was a decrease in mean value of pulmonary ventilation parameter (VC = 84.6%PRED, FEV1 = 51.8%PRED, MVV = 40.0%PRED) and diffusion parameter (DLCOadj = 77.8%PRED) This study also indicated a increase in the mean values of pulmonary static parameter (TLC = 130%PRED, FRC = 145%PRED, RV = 207% PRED) and resistance airway (Raw = 570%SLT) 99 Journal of military pharmaco-medicine No7-2017 Relationship between parameters values and the stages of COPD Figure 1: Relationship between pulmonary ventilation parameters and stages of COPD Figure 2: Relationship between pulmonary statics parameters and stages of COPD Figure 3: Relationship between raw parameter and stages of COPD Figure 4: Relationship between the alveolar capillary diffusion and stages of COPD 100 Journal of military pharmaco-medicine no7-2017 The relationship between parameters of respiratory functional exploration and the stages of COPD was shown in figure 1, 2, 3, In addition to FEV1, the parameters reflecting high relationship with stages of COPD include MVV (eta = 0.701), RV/TLC (eta = 0.686), Raw (eta = 0.414), DLCO (eta = 0.583) DISCUSSION Characteristics of the study patients with COPD In this study, male represented predominantly (97.4%), female made up only 3.2%, which reflects the gender characteristics of the COPD in Vietnam Dinh Ngoc Sy's research showed that the prevalence in men was higher than that in women (7.1% vs 1.9%) [3] There was a large proportion of malnutritionpatients (47%) Study by Mai Xuan Khan (2005) also had the same results (38% of patients had BMI < 18) [1] There are many causes leading to poor health in patients with COPD: poor eating, anorexia, inadequate diet, fatigue, depression, while their muscle respiratory must require a lot of energy In this study, group D (high risk, multiple symptoms) had the highest number of patients (57.3%) Therefore, patients with COPD were hospitalized at the late stage Identify the lung functional parameters Table showed that a decrease in mean values of pulmonary ventilation parameters: mean VC = 84.6%PRED, mean FEV1 = 51.8%PRED, mean MVV = 40.0%PRED in patients with COPD MVV was a parameter of the global respiratory musculature system and this measuring technique is not only uncomplicated but it provides standard and early ventilatory information as well Further, Tual’s study showed that if MVV value was more than 60% of PRED, respiratory complications after surgery were less likely [9] Thus, MVV examination was also necessary to apply the technique of reducing volume pulmonary for patients with COPD for previous risk of complication Table also showed an increase in mean values for pulmonary expansion parameters in patients with COPD: mean TLC = 130.5%PRED, mean FRC = 145.6%PRED, mean RV = 207.2% PRED, mean RV/TLC = 0.628 Fishman A.P [8] also found that the first change in the lung volume of patients with COPD was RV values and then increased the FRC value, to TLC value (at the fin) Increasing raw value was an early sign in the diagnosis of airway obstruction in patients In patiens with COPD, the resistance of small airway (less than mm in diameter) was more than 50% Meanwhile, in healthy people, this rate was only 25% In this study, difusing parameters were taken after adjustment for Hb Table showed a significant reduction in mean parameter of alveoli capillary diffusion CO in patients with COPD; 12.4 ± 11.2 mmolCO/min/mmHg, respectively, 77.8 ± 29.6%PRED The main cause of decrease in DLCO parameter value is due to chronic airway obstruction The KCO or DLCO/VA (carbon monoxide transfer 101 Journal of military pharmaco-medicine No7-2017 coefficient) was also reduced by 2.9 ± 0.9 and only 77.6 ± 24.4%PRED This is a result of CO transport across unit of pulmonary volume KCO reduction is more meaningful than whole reduction of DLCO Because if partial reduction of KCO is usually compensated by increasing the volume of the alveoli, the total DLCO may not change However, in patients with emphysema, pulmonary capillary was damaged by partial reduction of vascular system attached Therefore, the alveolar volume may be increased, the diffusing capacity of the lungs for carbon monoxide decreases [7] correlated with dyspne, so it was proposed to evaluate the treatment efficacy Figure showed that resistance airway was related (eta = 0.414) with stages of severity of disease The result of figure demonstrated DLCO parameters also associated moderately with the severity A, B, C, D of the COPD (eta = 0.583) Relationship between parameters values and the stages of COPD In patients with COPD, there was a decrease in pulmonary ventilation parameters value (FEV1, VC, MVV) and alveolar capillary diffusion (DLCO, KCO) and an increase in the parameters for lung statics (RV, TLC) and resistance airway (Raw) This change associated with the severity of stages of COPD In addition to FEV1 parameter, MVV, RV/TLC, Raw, DLCO parameters were significantly related with stages of severity (eta = 0.701, eta = 0.686, eta = 0.414, eta = 0.583 with p < 0.05) Figure 1, 2, 3, showed that all parameters were related with the stages of A, B, C, D For pulmonary ventilation parameters in figure 1, FEV1 had the highestassociation (eta = 0.737), followed by MVV (eta = 0.701), VC (eta = 0.542) This study confirms that FEV1, MVV parameters also were alway good representatives for the classification Figure found that in static pulmonary parameters, the RV/TLC ratio was most strongly related with the classification A, B, C, D (eta = 0.686) The Deesomchok’s study suggested that the extention pulmonary means evaluating the severity of the disease [6] Chen H [5] demonstrated that emphysema had moderate correlation with RV (r = 0.68) but only weak correlation with FEV1 (r = -0.13) Casanova C [4] also found that RV/TLC ratio was significantly 102 In particular, the study showed a serious and significant change of all parameters in COPD patients of group D Beside FEV parameter, MVV, RV/TLC ratio, Raw, DLCO parameters can also help to evaluate the patient's prognosis CONCLUSIONS REFERENCES Mai Xuân Khẩn Một số đặc điểm lâm sàng, chức hô hấp, nội soi tế bào dịch rửa phế quản bệnh phổi tắc nghẽn mạn tính Luận án Tiến sỹ Y học Học viện Quân y 2005 Nguyễn Huy Lực Nghiên cứu đặc điểm thơng khí phổi khí máu động mạch bệnh nhân bệnh phổi tắc nghẽn mạn tính (COPD) Tạp chí Y học Thực hành 2010, (712), tr.34-35 Journal of military pharmaco-medicine no7-2017 Nguyễn Thị Xuyên, Đinh Ngọc Sỹ, Nguyễn Viết Nhung Nghiên cứu tình hình dịch tễ bệnh phổi phế quản tắc nghẽn mạn tính Việt Nam Tạp chí Y học Thực hành 2010, (704), tr.3-8 Casanova C et al Inspiratory-to-total lung capacity ratio predicts mortality in patients with chronic obstructive pulmonary disease.Am J Respir Crit Care Med 2005, 171 (6), pp 591-597 Chen H et al Correlation of pulmonary function indexes determined by low-dose MDCT with spirometric pulmonary function tests in patients with chronic obstructive pulmonary disease AJR Am J Roentgenol 2014, 202 (4), pp.711-718 Deesomchok A et al Lung hyperinflation and its reversibility in patients with airway obstruction of varying severity COPD 2010, Vol 7, pp.428-437 GOLD Global initiative for chronic obstructive lung disease Pocket guide to COPD diagnosis, management and prevention A guide for Health Care Professionals Updated 2035 2016 Tual L, Pr Gilles Dhonneur Quels intérêts la réalisation de EFR en préoperatoire J Verdier 2007 Wanc Tan et al COPD prevalence in 12 Asia-pacific countries and regions Respirology 2003, (2), pp.192-198 103 ... highest proportion (57.3%) Determination of parameters values in patients with COPD Table 2: Values of lung functional parameters of patients with COPD Lung functional parameters Pulmonary ventilation... pharmaco-medicine no7-2017 The relationship between parameters of respiratory functional exploration and the stages of COPD was shown in figure 1, 2, 3, In addition to FEV1, the parameters reflecting high... first change in the lung volume of patients with COPD was RV values and then increased the FRC value, to TLC value (at the fin) Increasing raw value was an early sign in the diagnosis of airway