Hydrogen/oxygen therapy for the treatment of an acute exacerbation of chronic obstructive pulmonary disease: results of a multicenter, randomized, double-blind, parallel-group controlled trial.

BACKGROUND: To investigate whether the administration of hydrogen/oxygen mixture was superior to oxygen in improving symptoms in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). METHODS: This prospective, randomized, double-blind, controlled clinical trial in 10 centres enrolled patient with AECOPD and a Breathlessness, Cough, and Sputum Scale (BCSS) score of at least 6 points. Eligible patients were randomly assigned (in a 1:1 ratio) to receive either hydrogen/oxygen mixture or oxygen therapy. Primary endpoint was the change from baseline in BCSS score at day 7. Adverse events (AEs) were recorded to evaluate safety. RESULTS: Change of BCSS score in Hydrogen/oxygen group was larger than that in Oxygen group (- 5.3 vs. - 2.4 point; difference: - 2.75 [95% CI - 3.27 to - 2.22], meeting criteria for superiority). Similar results were observed in other time points from day 2 through day 6. There was a significant reduction of Cough Assessment Test score in Hydrogen/oxygen group compared to control (- 11.00 vs. - 6.00, p < 0.001). Changes in pulmonary function, arterial blood gas and noninvasive oxygen saturation did not differ significantly between groups as well as other endpoints. AEs were reported in 34 (63.0%) patients in Hydrogen/oxygen group and 42 (77.8%) in Oxygen group. No death and equipment defects were reported during study period. CONCLUSIONS: The trial demonstrated that hydrogen/oxygen therapy is superior to oxygen therapy in patient with AECOPD with acceptable safety and tolerability profile. TRIAL REGISTRATION: Name of the registry: U.S National Library of Medicine Clinical Trials; Trial registration number: NCT04000451; Date of registration: June 27, 2019-Retrospectively registered; URL of trial registry record: https://www.clinicaltrials.gov/ct2/show/study/NCT04000451?term=04000451&draw=2&rank=1 .

[Effect of electroacupuncture on small airway function in patients with stable chronic obstructive pulmonary disease].

OBJECTIVE: To observe the regulatory effect of electroacupuncture (EA) on small airway function and exercise tolerance in patients with stable chronic obstructive pulmonary disease (COPD). METHODS: A total of 62 patients with stable COPD were randomized into an observation group (31 cases, 1 case dropped off) and a control group (31 cases, 5 cases dropped off). On the base of routine medication and aerobic exercise, the patients of the two groups all received EA at Danzhong (CV 17), Rugen (ST 18), Guanyuan (CV 4), Zhongwan (CV 12), Tianshu (ST 25) and Yingchuang (ST 16). In the observation group, filiform needles were used and inserted perpendicularly, 3 mm in depth. In the control group, the placebo needling method was performed, in which the needle was not inserted through skin at each point. In both groups, electric stimulation with low-frequency electronic pulse instrument was exerted, with continuous wave, 2 Hz in frequency, lasting 30 min each time in the two groups. The treatment was given once every other day, 3 times a week, for 14 treatments totally. Before and after treatment, the following indexes were compared in patients between the two groups, i.e. the lung function indexes (forced expiratory volume in first second [FEV1], forced vital capacity [FVC], the ratio of FEV1 to FVC [FEV1/FVC], maximal voluntary ventilation [MVV], the percentage of maximal expiratory flow [MEF] at 25% of FVC exhaled [MEF25], MEF50 and MEF75 in predicted value), cardiopulmonary exercise test indexs (metabolic equivalent [METS], oxygen uptake per kg body weight [VO2/kg], minute ventilation [VE], the percentage of oxygen pulse [VO2/HR] in predictd value, maximal minute ventilation [VEmax], ventilatory equivalent for oxygen [VE/VO2], ventilatory equivalent for carbon dioxide [VE/VCO2]), 6-minute walk distance (6MWD), the total score of COPD assessment test (CAT), the modified British Medical Research Council (mMRC) score and COPD comprehensive grade. RESULTS: After treatment, FVC%, MVV%, MEF75%, MEF50%, VO2/kg%, METs%, VEmax, VO2/HR%, 6MW and the total CAT score were all improved as compared with those before treatment in the observation group (P<0.05, P<0.01). After treatment, MEF75% and the total CAT score were reduced as compared with those before treatment in the control group (P<0.05). After treatment, MVV%, MEF50%, VO2/kg%, METs%, VEmax and 6MWD in the observation group were all better than those in the control group (P<0.05, P<0.01). CONCLUSION: Electroacupuncture can improve the respiratory function and exercise tolerance in COPD patients through removing small airway obstruction and increasing ventilation.

Erratum to hydrogen/oxygen mixed gas inhalation improves disease severity and dyspnea in patients with Coronavirus disease 2019 in a recent multicenter, open-label clinical trial.

[This corrects the article DOI: 10.21037/jtd-2020-057.].

[The relationship between mouth pressure or tracheal pressure and esophagus pressure and diaphragmatic pressure].

OBJECTIVE: To investigate the relationship between mouth pressure (Pmo) or tracheal pressure (Ptr) and esophagus pressure (Pes) or transdiaphragmatic pressure. METHODS: Seventeen patients were involved in the study. Maximal inspiratory pressure (MIP), maximal transdiaphragmatic pressure (Pdi(max)), maximal esophagus pressure (Pes(max)), twitch mouth pressure (TwPmo), twitch transdiaphragmatic pressure (TwPdi) and twitch esophagus pressure (TwPes) were measured before narcotization as a normal procedure for the abdominal operation and twitch tracheal pressure (TwPtr(nar)), twitch esophagus pressure (TwPes(nar)) and twitch transdiaphragmatic pressure (TwPdi(nar)) were dynamically monitored during narcotization. RESULTS: (1) The correlation coefficient (r) values between Pdi(max) and MIP, TwPdi and TwPmo, TwPdi(nar) and TwPtr(nar), Pes(max) and MIP, TwPes and TwPmo, TwPes(nar) and TwPtr(nar) were 0.976 +/- 0.030, 0.816 +/- 0.155, 0.923 +/- 0.446, 0.981 +/- 0.185, 0.829 +/- 0.168 and 0.955 +/- 0.292, respectively. (2) The coefficient variation (CV) of MIP, Pes(max), Pdi(max), TwPmo, TwPes and TwPdi were (14.2 +/- 4.7)%, (15.2 +/- 4.3)%, (15.5 +/- 4.1)%, (30.4 +/- 15.9)%, (10.8 +/- 5.1)% and (9.9 +/- 4.0)%, respectively. The CV of TwPmo was the highest (compare with others, all P < 0.05) and that of TwPes and TwPdi was the lowest (compare with others, all P < 0.05). There was no significant difference among MIP, Pes(max) and Pdi(max) (P > 0.05). (3) The r value between the changing values of TwPtr(nar) and TwPdi(nar) or TwPes(nar) during narcotization were 0.839 or 0.894 (P = 0.000, respectively). CONCLUSION: The measurement of MIP and TwPmo should be repeated and the highest value should be chosen in order to reduce the possibility of underestimating the function of diaphragm, which could be dynamically monitored by TwPtr(nar).

[Changes in pulmonary function in severe acute respiratory syndrome patients during convalescent period].

OBJECTIVE: To investigate the changes and pattern of pulmonary function in severe acute respiratory syndrome (SARS) patients during convalescent period. METHODS: Pulmonary function tests were performed in 26 SARS convalescent patients regularly every 3 months after their discharge from hospital. The significance of changes in pulmonary function indexes was analyzed. RESULTS: Restrictive pulmonary ventilation function and diffusing dysfunction of the lung were found in one third of the patients during third to sixth month from onset. There was a little improvement in forced vital capacity (FVC), one second forced expiratory volume (FEV(1.0)), functional residual capacity (FRC) and residual volume (RV) as convalescent period was prolonged, but no difference was found between different stages (3-6 months, 6-9 months, 9-12 months, 12-15 months and 15-17 months). Meanwhile, the FEV(1.0)/FVC showed no significant change. However, there was an obvious improvement in total lung capacity (TLC) and diffusing capacity of the lung for carbon monoxide (DLCO) with the elapse of time, and also a significant difference was found between the later stage and the earlier stage. CONCLUSION: Pulmonary dysfunction is found among some SARS patients after convalescence presenting mainly as restrictive ventilatory function and diffusing capacity abnormality. These dysfunctions would improve gradually with the elapse of time.

[Physiologic response to proportional assist ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease].

OBJECTIVE: To investigate the effect of different assist levels during proportional assist ventilation (PAV) on patients with acute exacerbation of chronic obstructive pulmonary disease (COPD). METHODS: Nine patients with acute exacerbation of COPD received different levels of assist ventilation during PAV. The change of inspiratory muscle effort and breathing pattern of the patients were observed. RESULTS: (1) The average tidal volume (V(T)), minute ventilation (V.(E)) and respiratory frequency (RR) were slightly higher during PAV, as compared to spontaneous breathing (SB). The change of breathing pattern of the patients was not significant at different assist levels during PAV. (2) The transdiaphragmatic pressure (Pdi), the pressure-time product (PTP) and work of breathing (Wi) reduced significantly during PAV as compared with SB (differently reduced 8.36 cm H2O, 11.49 cm H2O.s(-1).L(-1) and 0.53 J/L). The change in Pdi, PTP and Wi was small among different levels during PAV. (3) Dyspnea was improved during PAV. CONCLUSIONS: The present study confirms the feasibility of noninvasive ventilation PAV in treating patients with acute exacerbation of COPD. Based on the patient's assessment, the ventilatory support level which the patients could comfortably tolerate was (57 +/- 11)%. noninvasive ventilation PAV set at a level of comfort determined by the patient can unload inspiratory muscles; at the comfortable level of ventilatory support, Wi, Pdi and PTP decreased by 57%, 72% and 65% respectively. It also improved breathing pattern and dypnea.

Use of twitch mouth pressure to assess diaphragm strength in patients with chronic obstructive pulmonary disease.

This study was undertaken to determine whether twitch mouth pressure (TwPmo) can reliably assess diaphragm strength in patients with chronic obstructive pulmonary disease (COPD) using fully automatic trigger techniques. Fifteen patients with COPD were recruited. TwPmo, twitch oesophageal pressure (TwPes) and twitch transdiaphragmtic pressure (TwPdi) were generated by phrenic nerve stimulation and were measured using an inspiratory flow trigger (40 ml/s, Experiment 1) using an inspiratory pressure trigger (-5 cmH2O, Experiment 2) and using no trigger at functional residual capacity (Experiment 3). The correlation between TwPmo and TwPes was as follows: r=0.832; P<0.0001 (Experiment 1), r=0.900; P<0.0001 (Experiment 2); there was no significant correlation in Experiment 3. A Bland-Altman plot of the difference between TwPmo and TwPes showed the limits of agreement in Experiment (1) bias (range) 0.18 cmH2O (-2.05 to 2.41) and Experiment (2) bias (range) 0.32 cmH2O (-1.69 to 2.32). Measuring TwPmo using a fully automatic technique is a simple and convenient method for assessing diaphragm strength.