Objective To investigate the application of sequential noninvasive ventilation (NIV) in weaning patients off mechanical ventilation after coronary artery bypass grafting (CABG). Methods From July 2007 to July 2009, 52 patients who underwent CABG with mechanical ventilation for no less than 24 hours and P/F Ratio lower than 150 mm Hg were divided into two groups with random number table. In the sequential NIV group (SNIV group), there were 19 patients including 16 males and 3 females whose ages were 69.26±8.10 years. In the prolonged mechanical ventilation group (PMV group), there were 33 patients including 28 males and 5 females whose ages were 70.06±7.09 years. Clinical data of these two groups were compared and the influence of NIV on the circulation and respiration of the patients were observed. Results The SNIV group weaned off mechanical ventilation earlier than the PMV group (26.46±3.66 h vs. 38.65±9.12 h, P=0.013). The SNIV group held shorter total ventilation time (29.26±21.56 h vs.54.45±86.57 h,P=0.016), ICU stay time (2.44±2.99 d vs. 4.89±7.42 d, P=0.028) and postoperative hospital time (10.82±4.31 d vs. 14.01±19.30 d, P=0.039) than the PMV group. Furthermore, the SNIV group had lower pneumonia rate (5.26% vs. 30.30%, P=0.033) and total postoperative complication rate (10.53% vs.45.45%, P=0.030) than the PMV group. However, there was no significant difference (Pgt;0.05) between the two groups in the successful weaning rate, repeated tracheal intubation rate, tracheotomy rate and mortality 30 days after operation. After NIV, SNIV group had no significant change in heart rate, central vein 〖CM(1585mm〗pressure, pulmonary arterial pressure and pulmonary arterial wedge pressure than the baseline value, while systolic pressure (129.66±19.11 mm Hg vs. 119.01±20.31 mm Hg, P=0.031), cardiacindex ［3.01±0.30 L/(min.m2) vs. 2.78±0.36 L/(min.m2), P=0.043］ and P/F Ratio (205.95±27.40 mm Hg vs. 141.33±9.98 mm Hg, P=0.001) were obviously elevated. Conclusion Sequential NIV is a effective and safe method to wean CABG patients off mechanical ventilation.
Objective To investigate the safety of high fraction of inspired oxygen (FiO2)during noninvasive ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD)and carbon dioxide (CO2)retention. Methods Fifty-six AECOPD patients with CO2 retention admitted between March 2013 and August 2015 were recruited in the study.All patients received noninvasive ventilation treatment with FiO2<0.5.After stabilization of acute respiratory crisis,FiO2 was increased to 1.0 and lasted for 40 minutes.The changes of tidal volume,respiratory frequency,minute volume,Glasgow coma score,arterial blood gas and SpO2 were observed before and after the FiO2 reset. Results The mean PaO2 increased from (83±14)mm Hg to (165±41)mm Hg and the mean SpO2 increased from (92.4±3.1)% to (97.8±1.9)% significantly (both P<0.001).The mean PaCO2 did not changed obviously from (72±15)mm Hg to (72±14)mm Hg (P=0.438).There were also no significant changes in any of the other parameters. Conclusion During noninvasive ventilation with an FiO2 sufficient to maintain a normal PaO2,an increase in FiO2 does not further increase PaCO2 level in AECOPD patients with CO2 retention.
目的 比较无创双水平正压通气（BiPAP）平均容积保证压力支持（AVAPS）模式与同步/时间控制（S/T）模式在肥胖的慢性阻塞性肺疾病（COPD）患者并发急性Ⅱ型呼吸衰竭中的治疗作用。 方法 选取2012年3月－2013年6月入院治疗且体质量指数（BMI）＞25 kg/m2的COPD发生急性Ⅱ型呼吸衰竭患者36例，按数字随机表法分为AVAPS组与S/T组。两组的基础治疗相同，AVAPS组采用飞利浦伟康V60呼吸机BiPAP AVAPS模式进行无创通气治疗，S/T组采用相同机型BiPAP S/T模式治疗。分别比较两组患者治疗1、6、24、72 h的格拉斯高昏迷（GCS）评分变化、血气分析结果、呼吸机监测数据。 结果 AVAPS组患者在最初治疗的6 h内GCS评分高于S/T组[1 h：（13.2 ± 0.6）、（11.9 ± 0.6） 分，P＜0.05；6 h：（13.8 ± 0.5）、（12.1 ± 0.6）分，P＜0.05]；24 h内的动脉血气酸碱度pH值改善[1 h：7.31 ± 0.03、7.26 ± 0.02，P＜0.05；6 h：7.37 ± 0.05、7.31 ± 0.04，P＜0.05]；24 h：7.40 ± 0.04、7.33 ± 0.03，P＜0.05]及二氧化碳分压下降[1 h：（65.2 ± 5.1）、（69.5 ± 4.1）mm Hg（1 mm Hg=0.133 kPa），P＜0.05；6 h：（61.4 ± 4.2）、（66.7 ± 4.3） mm Hg，P＜0.05；24 h：（58.2 ± 4.5）、（64.3 ± 5.4） mm Hg，P＜0.05）]优于S/T组，24 h内浅快呼吸指数低于S/T组[1 h：（35.2 ± 8.1）、（62.8 ± 13.2）次/（min·L），P＜0.05]；6 h（33.4 ± 7.8） 、（54.8 ± 11.6）次/（min·L），P＜0.05]，同时，减少了额外的人工参数调整次数[3.4 ± 1.1、1.2 ± 0.6），P＜0.05] 结论 对超重的COPD合并急性Ⅱ型呼吸衰竭患者采用AVAPS模式进行无创通气治疗，较S/T模式能更快地恢复意识水平，更快地降低血二氧化碳分压、改善pH值，同时减少了呼吸治疗师的人工操作次数。
In China, chronic respiratory diseases (CRD) are characterized by high prevalence, disability rate, and mortality rate, imposing a severe disease burden. Home non-invasive ventilation (HNIV) therapy can improve ventilation, alleviate respiratory muscle fatigue, enhance oxygenation and carbon dioxide retention, delay the progression of various CRD, and even improve survival. However, there is currently a lack of long-term management standards and standardized guidance for patients receiving HNIV therapy in China. The Respiratory Therapy Group of the Chinese thoracic Society and Chinese Association of Rehabilitation Medicine, has summarized 11 questions related to HNIV for different diseases, answered various questions, and put forward modification suggestions. This consensus aims to provide references for frontline clinical staff, promote the standardization of HNIV application in China, and improve the level of treatment.Summary of recommendationsQuestion 1. For which patients is HNIV suitable?Recommendation: HNIV is recommended for patients with ventilatory dysfunction due to various causes, such as: obstructive sleep apnea syndrome [high-quality evidence, strong recommendation], chronic obstructive pulmonary disease [high/moderate-quality evidence, strong recommendation], obesity hypoventilation syndrome [moderate/low-quality evidence, strong recommendation], and neuromuscular diseases [low-quality evidence, strong recommendation].Question 2. When should HNIV be initiated?Recommendation: The timing for initiating HNIV therapy should be based on a comprehensive assessment of disease diagnosis, severity, symptoms, and comorbidities. Early standardized intervention is a crucial measure for improving prognosis and reducing long-term disease burden. Specific recommended indications are listed in Table 2. [high/moderate quality evidence, strong recommendation]Question 3. How should health education on HNIV be conducted?Recommendation: All HNIV patients should receive educational training. The five-step training method is recommended as the preferred approach for educating HNIV patients and their families. [Moderate-quality evidence, weak recommendation]Question 4. How to properly select a home non-invasive ventilator?Recommendations: When selecting a home non-invasive ventilator, patients should first consult a professional physician or respiratory therapist to obtain specialized advice based on their specific condition. Physicians should make decisions by comprehensively considering the patient’s disease type and severity, ventilator modes and parameters, synchrony, comfort, remote monitoring requirements, and financial circumstances. Refer to Table 3 for ventilation mode selection based on different diseases.Question 5. How should accessories for HNIV be selected?Recommendation: Mask selection should be based on disease type, dynamic assessment of the patient’s breathing pattern, and patient preference, with regular reassessment of fit during follow-up [High/moderate-quality evidence, strong recommendation]. Active heated humidifiers are recommended as the first choice for HNIV patients [Low-quality evidence, weak recommendation].Question 6. How should HNIV parameters be set and adjusted?Recommendation: Parameter adjustments should be performed in hospital and community settings. Long-term home use should only commence after confirming appropriate and safe settings. Avoid patients or caregivers making arbitrary adjustments that may cause adverse events. [Moderate-quality evidence, strong recommendation]Pressure settings for NIV should be tailored to the patient’s underlying disease and clinical objectives. Additional parameters including backup rate, inspiratory sensitivity, pressure rise time, and expiratory sensitivity must also be configured. The setup process is summarized in Figure 1. [Moderate-quality evidence, strong recommendation]Question 7. What is the recommended daily usage duration for HNIV?Recommendation: For patients using HNIV due to sleep apnea or sleep-related hypoventilation, it is recommended to use the device for at least 4 hours daily on more than 70% of nights, with usage duration covering sleep periods as much as possible. For patients using HNIV due to chronic hypercapnia, daily use of at least 5 - 6 hours is required, with priority given to nighttime use. [Low-quality evidence, weak recommendation]Question 8. When should respiratory support be adjusted during HNIV?Recommendation: Assess the efficacy of HNIV based on clinical and physiological criteria to determine whether to continue ventilatory support [Moderate-quality evidence, strong recommendation]. If disease progression or complications arise, and HNIV can no longer maintain effective ventilation, discontinue HNIV and seek hospital care promptly [Low-quality evidence, strong recommendation]. HNIV should not be discontinued in patients requiring intermittent or continuous HNIV during exercise [Moderate-quality evidence, strong recommendation].Question 9. How should complications associated with HNIV be managed?Recommendation: Common complications of noninvasive ventilation include skin pressure injury, air leak, patient-ventilator asynchrony, and thick sputum. These should be actively prevented and managed during HNIV. [Moderate-quality evidence, strong recommendation]Question 10. How should the effectiveness of HNIV be assessed and followed up?Recommendation: Close monitoring and follow-up are recommended for patients receiving home noninvasive ventilation. Monitoring indicators and follow-up frequency are summarized in Table 6. [Moderate-quality evidence, GPS]Question 11. How should the management pathway for HNIV be established and optimized?Recommendations: Establish a tiered, dynamic, and individualized HNIV management pathway based on patient condition characteristics, technical support availability, and home care capabilities: ① For high-risk acute exacerbation/unstable patients: Primarily use the traditional "hospital-community-home" model supplemented by self-management; for low-risk acute exacerbation/stable patients: Primarily use self-management with IoT-based remote monitoring where feasible. ② Dynamically adjust based on disease stage: intensify in-person training during the initial phase and gradually transition to remote monitoring during the stable phase; ③ Promote multidisciplinary collaboration, utilize smart devices for real-time monitoring, and ensure data security; ④ Enhance patient self-management capabilities through standardized education and regular follow-ups. [Low-quality evidence, GPS]
Objective To evaluate the influence on the estimation of respiratory mechanics with dynamic signal analysis approach during noninvasive positive pressure ventilation (NPPV) under different inspiratory effort conditions. Methods The Respironics V60 ventilator was connected to a ASL5000 lung simulator, which simulate lung mechanics in healthy adults with body weight from 65 to 70 kg, and patients with chronic obstructive pulmonary disease (COPD) and acute respiratory distress (ARDS). Each lung models was subjected to 4 different muscle pressures (Pmus): 0, 5.0, 10.0, and 15.0 cm H2O. Inspiratory pressure support level was adjusted to maintain tidal volume (VT) achieving 7.0 mL/kg outputted by ventilator respectively. Positive end expiratory pressure was set at 5.0 cm H2O and back-up rate was 10 beats per minute. Measurements were conducted at system leaks with 25 to 28 L/min. The respiratory system compliance (Crs), inspiratory and expiratory resistance (Rinsp and Rexp) were estimated by special equations, which was derived from the exhaled VT, flow rate and airway pressure. Results The driving pressure (DP) was decreased with Pmus increasing, and was 1.0 cm H2O after Pmus exceeding 10.0 cm H2O and the VT was larger than 7.0 mL/kg in normal adult model. The estimated value of Crs was affected by the changes of Pmus in all three lung models. The significant underestimation of Raw and the overestimation of Crs were observed when Pmus level exceed 10.0 cm H2O. The measured errors of Crs and Rexp were within 10% in COPD and ARDS model when Pmus was at 5.0 cm H2O. The underestimation of Rinsp was always existed in all Pmus level (P<0.01). Conclusions Using dynamic signal analysis approach, the real-time estimation of respiratory mechanics (Crs and Raw) is no need to interrupt the spontaneous breathing during NPPV. Excessive effort will increase the patient’s inspiratory workload, which is not benefit to accurate estimation of respiratory mechanics.
Objective To compare the effects of oxygen therapy and local pressurization in alleviating plateau hypoxia at high altitude. Methods Forty-five healthy male soldiers were investigated at an altitude of 3992 meters. The subjects were randomly divided into three groups, ie. an oxygen inhalation group, a single-soldier oxygen increasing respirator ( SOIR) group and a BiPAP group. The oxygen inhalation group was treated with oxygen inhalation via nasal catheter at 2 L/ min. SOIR was used to assist breath in the SOIR group. The BiPAP group were treated with bi-level positive airway pressure ventilation, with IPAP of 10 cm H2O and EPAP of 4 cmH2 O. PaO2, PaCO2, SpO2 and heart rate were measured before and 30 minutes after the treatment. Results There were continuous increase of PaO2 from ( 53. 30 ±4. 88) mm Hg to( 58. 58 ±5. 05) mm Hg and ( 54. 43 ±3. 01) mm Hg to ( 91. 36 ±10. 99) mm Hg after BiPAP ventilation and oxygen inhalation, respectively ( both P lt; 0. 01) . However, the PaO2 of the SOIR group was decreased from( 56. 00 ±5. 75) mm Hg to ( 50. 82 ±5. 40) mm Hg( P lt; 0. 05 ) . In the other hand, the PaCO2 was increased from ( 30. 41 ±1. 51) mmHg to ( 32. 56 ±2. 98) mm Hg in the oxygen inhalation group ( P lt; 0. 05) , declined from( 28. 74 ±2. 91) mm Hg to ( 25. 82 ±4. 35) mm Hg in the BiPAP group( P lt;0. 05) ,and didn’t change significantly from( 28. 65 ±2. 78) mm Hg to ( 29. 75 ±3. 89) mmHg in the SOIR group ( P gt;0. 05) . Conclusions Both BiPAP ventilation and oxygen inhalation can alleviate plateau hypoxia by improving PaO2 at 3992 meter altitude while SOIR has no significant effect.