Objective To investigate the effects of different inspiratory rise time during noninvasive positive pressure ventilation ( NPPV) on work of breathing in patients with acute exacerbation of chronic obstructive pulmonary disease ( COPD) . Methods Eleven patients with acute exacerbation of COPD received different inspiratory rise time ( 0. 1sec, 0. 3sec, 0. 5sec) during NPPV. The changes of inspiratory muscle effort and breathing pattern of the patients were observed. Results The average respiratory rate,minute ventilation, and tidal volume were higher during NPPV compared with spontaneous breathing. But the changes of average minute ventilation and tidal volume were not significant ( P gt; 0. 05) . The pressure time product ( PTP) , transdiaphragmatic pressure ( Pdi) , and work of breathing of inspiratory muscle reduced significantly during different inspiratory rise time as compared with spontaneous breathing ( P lt;0. 01) . PTP,Pdi, and work of breathing reduced 59. 2% , 62. 7% , and 49% respectively when inspiratory rise time was 0. 1sec. They reduced more significantly during inspiratory rise time of 0. 1sec. Conclusions The present study confirms NPPV can unload inspiratory muscles in patients with acute exacerbation of COPD. It is more effective to reduce inspiratory load when inspiratory rise time is set at 0. 1sec while the patients feel most comfortable.
ObjectiveTo investigate the clinical characteristics of polymyositis (PM)/dermatomyositis (DM) with acute interstitial pneumonia (AIP) as the presenting symptoms, and identify characteristics of such disease. MethodsA retrospective analysis was conducted on the hospitalized patients with PM/DM with AIP as the presenting symptoms, from October 2009 to June 2015 in the Departemnt of Respiratory Medicine, Guangzhou Institute of Respiratory Diseases. ResultsThey were two males and six females with a mean age of 54.8±7.5 years. The common clinical features included fever (8 cases), shortness of breath (8 cases), rapidly progressive exertional dyspnea (8 cases), dry cough (6 cases), decreased muscle strength (8 cases), and typical rash (7 cases). Electromyography showed neurogenic or myogenic leision in these 8 cases. Muscle biopsy revealed myositis in 7 cases. High resolution CT (HRCT) revealed widespread ground glass patterns in all patients. All patients received noninvasive positive pressure mechanical ventilation on the first hospital day. High dose of methylprednisolone or combination with intravenous cyclophosphamide were initiated on 2.3±1.4 hospital day. Six patients survived to hospital discharge and two patient died. ConclusionsThe most common symptoms in patients of PM/DM with AIP are shortness of breath, progressive exertional dyspnea, and dry cough. Typical rash is seen in most of the patients.The diagnosis can be established by combinating the characteristics of HRCT, electromyography and muscle biopsy. Earlier intervention with noninvasive positive pressure mechanical ventilation and immunosuppressive may improve clinical outcome in patients of PM/DM with AIP.
Objective To assess the effect of continuous positive airway pressure ( CPAP) on expiratory flow limitation in severe chronic obstructive pulmonary disease ( COPD) patients during noninvasive ventilation by oscillatory reactance ( Xrs ) . Methods Eight patients with stable COPD and chronic hypercapnic respiratory failure( type II) received noninvasive ventilation with a traditional CPAP ventilator through a nasal mask were enrolled. The CPAP were successively set as 4, 8 and 12 cm H2O respectively. The forecd oscillation( 5 Hz, 2 cm H2O) was imposed into the mask and the flow and nasal pressure were measured at the airway opening. The difference between inspiratory and expiratory Xrs( ΔXrs)were calculated for each breathing cycle and average ΔXrs was calculated at different pressure levels according to the established algorithm. Meanwhile, the oesophageal pressure was also measured by a balloontipped catheter and transpulmonary pressure was calculated. The breathing cycles above were analyzed subsequently and classified as expiratory flow-limited( EFL) and non-EFL breath. In addition, flow and nasal pressure when breathing naturally( CPAP = 0 cmH2O) was also collected for each patient and the EFL breath cycles was identified as baseline. Then, the percentage of EFL breathing cycles and ΔXrs were calculated for each CPAP level and their relationship was analyzed. The threshold value of ΔXrs with maximum sensitivity and specificity to detect EFL and the optimal CPAP to suppress the development of EFL were computed. Results ①CPAP increased from4 to 8 and 12 cm H2O resulted in fall of mean values of ΔXrs from2. 67 to 1. 62 and 1. 31 cm H2O· s- 1 · L- 1 , respectively( ΔXrs at CPAP 0 cm H2O was not detected) , and the decrease of ΔXrs when CPAP up to 8 cm H2O from 4 cm H2 O was significant ( Z = - 2. 68, P = 0. 01) . ②CPAP significantly suppressed the development of EFL, when CPAP increased from0 cm H2O to 4,8 and12 cmH2O resulted in decrease in the percentage of breathing cycle from 29. 8% to 9. 9% , 8. 1% and 4. 4%, respectively( 2 = 15. 6, P = 0. 01) . ③ ΔXrs was related to the degree of EFL and the mean value of ΔXrs in EFL breathing cycles was significantly higher than that in non-EFL’s. When ΔXrs decreased to 1. 83 cm H2O· s- 1 · L- 1, the majority of breath showed non-EFL, with a sensitivity of 94% and specificity of 97% for detecting EFL, respectively. Conclusions ΔXrs is an indicator of the occurrence of EFL. Appropriate CPAP to render the value of ΔXrs equal to or slightly less than 1. 83 cm H2O·s - 1 ·L- 1 may effectively suppress the development of EFL in severe COPD patients during noninvasive ventilation.
ObjectiveTo evaluate the effectiveness of different biopsy methods in the diagnosis of idiopathic interstitial pneumonia (IIP). MethodsA retrospective analysis was performed in patients hospitalized and diagnosed as IIP between January 2010 to December 2013 in the Department of Respiratory Medicine, the First Affiliated Hospital of Guangzhou Medical University. The patients were divided based on initial diagnoses. The performance of invasive examinations including both transbronchoscopic lung biopsy (TBLB) and surgical lung biopsy (SLB) and final diagnoses were recorded. ResultsThree hundred and ninety-one patients were included in the study with mean age of 62.5±11.9 years. There were 299 patients receiving TBLB, 43 patients receiving SLB, and 49 patients receiving non-invasive examinations. Among 299 patients who underwent TBLB, parenchymal tissue was not obtained in 132 (44.1%) but successfully obtained in 167 (55.9%) patients, with 79 (47.3% out of 167) clinically helpful. TBLB-based specific diagnoses were as follows:30 cases of non-specific interstitial pneumonia (NSIP), 22 cases of cryptogenic organizing pneumonia (COP), 18 cases of idiopathic pulmonary fibrosis (IPF), 4 cases of acute interstitial pneumonia (AIP), 2 cases of respiratory bronchiolitis-interstitial lung disease (RB-ILD) and lymphocytic interstitial pneumonia (LIP) for each, 1 case of desquamative interstitial pneumonia (DIP), respectively. Among 43 patients who underwent SLB, parenchymal tissue was obtained in all cases with 40(93.0% out of 43) pathologically diagnostic, including 20 cases of NSIP, 12 cases of IPF, 3 cases of COP and LIP for each, and 2 cases of RB-ILD and DIP for each. Finally, among 181 patients who failed to obtain parenchymal tissue or did not undergo invasive examination, specific diagnoses could be established in 40 patients with all finally diagnosed as IPF. ConclusionsThe pathological diagnosis, either based on TBLB or SLB, is very important in the diagnostic procedure of IIP. The biopsy technique of hospital and patient conditions should be considered when making the decision of biopsy method.
ObjectiveTo analyze the benefits of lung transplantation in the treatment of interstitial lung disease (ILD) and investigate its prognostic factors.MethodsThe clinical data of patients diagnosed with ILD and meet the lung transplantation criteria were retrospectively analyzed from January 2012 to December 2017 in the First Affiliated Hospital of Guangzhou Medical University. A total of 111 patients, 88 males and 23 females, aged (58.3±11.4) years old, were divided into lung transplantation group and non-lung transplantation group. Clinical data and prognosis of the two groups were compared and the factors affecting the prognosis of lung transplantation were analyzed with relevant literatures. Results There were 56 patients in lung transplantation group and 55 patients in non-lung transplantation group. The mainly underlying disease of both groups were idiopathic pulmonary fibrosis (IPF). There was no significant difference in age, body mass index, arterial partial pressure of oxygen, percentage of forced vital capacity in the estimated value, percentage of diffusing capacity of the lung for carbon monoxide in the estimated value, six-minute walk distance between the two groups (P>0.05). The pulmonary arterial hypertension and arterial partial pressure of carbondioxide were higher in lung transplantation group than non-transplantation group (P<0.05). The 1-year survival rate in the lung transplantation group was significantly higher than that in the non-lung transplantation group: 77.4% vs. 32.7% (P<0.01). COX regression analysis showed that preoperative ventilator dependence, serum creatinine, bilirubin, pulmonary artery pressure, and procedures (single lung vs. double lung) had no significant effect on the prognosis of lung transplantation; age and preoperative diabetes mellitus were risk factors for the prognosis of lung transplantation.ConclusionsLung transplantation can significantly improve the prognosis of patients with ILD who are refractory to medicine therapy. IPF patients should be advised to consider lung transplantation as soon as possible. Age and preoperative diabetes mellitus are risk factors for the prognosis of lung transplantation.