建立人工气道实施机械通气是治疗严重呼吸衰竭过程中挽救患者生命最常用的措施之一，然而通过人工气道的机械通气也增加了相关并发症发生的机会，如呼吸机相关性肺炎（VAP）等[1]。多数患者在应用呼吸机进行通气支持治疗中，当呼吸衰竭及其病因的病情缓解或明显改善时就可以解除人工气道和终止通气支持，但20%~30%的患者需要逐渐解除呼吸机的通气支持，谓之撤机（Weaning）[1]。尽管文献中撤机的定义略有不同，但主要指的是需要逐步减弱及停止通气支持和解除人工气道的一个时间过程。有慢性呼吸功能不全的患者撤机尤为困难，撤机困难患者的撤机时间可占总机械通气时间的40%[2]。机械通气时间延长与VAP发生率和病死率增加相关。一般来说，机械通气时间gt;3 d，VAP的发生率增加；机械通气时间gt;5 d，并发的VAP为晚发性医院获得性肺炎（HAP），其感染的病原体多为耐多药细菌，治疗难度加大，病死率高于早发性HAP。因此，对于机械通气患者来说，一旦建立人工气道实施有创通气，就应该积极创造条件，尽快撤机，去除人工气道。然而过快地降低和停止通气支持以及过早的气管拔管，可导致撤机失败和再插管。因此时机不成熟的撤机和延时撤机同样可造成机械通气时间过长，导致VAP发生率和病死率升高，以及医疗费用增加[2]。撤机的模式和方法有多种，但最佳的撤机方式仍有争议[1]。近年来无创通气（NIV）作为一种撤机方式用于临床已引起人们的兴趣和关注，但至今临床研究所得结论并未达到一致，NIV是否可以作为一种常规撤机方式用于临床尚无定论。本文通过总结近年来相关的临床研究，评价NIV用于机械通气撤机的可行性和利弊，探讨需进一步优化研究方案来解决的有关问题。
目的 研究无创通气(NIPPV)治疗对肾移植术后巨细胞病毒(CMV)肺炎患者的疗效。方法 1998年1月~2005年12月间入住中山大学附属第一医院内科重症监护病房(MICU)的78例肾移植术后CMV肺炎患者，根据是否接受无创通气治疗而分为非NIPPV组和NIPPV组，比较两组患者在接受有创机械通气比例、病死率、住院时间及并发症等方面的差异。对52例NIPPV组患者，比较无创通气治疗前后生命体征及血气分析指标的变化。结果 NIPPV组与非NIPPV组相比，接受有创机械通气比例(30.8％ 比80.8％)、医院获得性肺炎发生率（32.7％ 比61.5％)及病死率(30.8％ 比57.7％)较低，两组比较均有显著性差异(P均lt;0.05)；而住院时间、气压伤发生率无显著差异。NIPPV组患者无创通气治疗后患者呼吸频率有所减慢，动脉血pH值逐渐降低，PaCO2水平缓慢上升，PaO2、PaO2 ／FiO2及SaO2明显升高，两组比较均有显著差异(P均lt;0.05)。而无创通气治疗前后心率、血压的变化则无明显规律。结论 NIPPV治疗能够改善肾移植术后CMV肺炎患者的低氧血症，缓解呼吸窘迫症状，降低有创机械通气治疗比例及医院获得性肺炎的发生率，从而降低病死率。用无创通气治疗巨细胞病毒肺炎值得在临床上推广使用。
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.
Objective This is a meta-analysis of the efficacy of noninvasive ventilation (NIV) with helmet compared to NIV with face mask in patients with acute respiratory failure (ARF). Methods " Helmet, face mask or facial mask” and " mechanical ventilation or noninvasive ventilation” were used as key words both in Chinese and English to search all the trials in PubMed, OVID, Embase, Scopus and Cochrane Library, websites, reference lists of articles, CNKI and Wanfang Database from inception to December 2016. Two reviewers independently assessed the methodological quality of the trials and extracted information. Revman 5.3 was used for data analysis. Results Ten randomized controlled trials (RCTs) and six case-control trials were included. NIV with a helmet reduced the intubation rate (OR=0.35, 95%CI 0.24 to 0.51, P<0.000 01), in-hospital mortality rate (OR=0.51, 95%CI 0.34 to 0.76, P=0.001), and NIV-related complications (OR=0.10, 95%CI 0.06 to 0.15, P<0.000 01) compared to NIV with face mask. There was no significant difference in gas exchange between two groups. In the subgroup analysis, types of ARF and ventilation mode did not affect the intubation rate and the complications relevant to NIV, but NIV with helmet mainly decreased the in-hospital mortality of the patients with hypoxemic ARF or pressure support ventilation. Conclusions NIV with a helmet can decrease the endotracheal intubation rate, in-hospital mortality, and NIV-related complications of the patients with ARF. And helmet is as effective as face mask in improving the gas exchange. However, larger or multicenter RCTs are needed to analyze the role of NIV with a helmet in this condition.
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.
Neuromuscular disease (NMD) encompasses a group of disorders that affect motor neurons, peripheral nerves, neuromuscular junctions, and skeletal muscles, potentially leading to respiratory muscle impairment and decline in respiratory function, significantly impacting patients' quality of life. In March 2023, clinical practice guideline titled Respiratory Management of Patients with Neuromuscular Weakness was released by the American College of Chest Physicians. This article summarizes, categorizes, and interprets the contents and key points of the guideline, aiming to provide more targeted guidance for clinical healthcare professionals and ultimately enhance the effectiveness of respiratory management for patients with NMD.
Objective To study the changes of receptor activator of nuclear factor-κB ligand (RANKL, an osteoclastogenesis-promoting factor) and osteoprotegerin (OPG, the decoy receptor for RANKL), oxidative stress and bone turnover markers in obstructive sleep apnea-hypopnea syndrome (OSAHS), in order to understand the potential mechanisms underlying bone loss in OSAHS patients. Methods Ninety-eight male patients with OSAHS, confirmed by polysomnography (PSG) study, were enrolled. The patients were divided into mild-moderate groups and severe groups. Forty-two male subjects who were confirmed as not having OSAHS served as the controls. The subjects’ bone mineral density (BMD) and T-score were assessed in lumbar spine and femoral neck using dual-energy X-ray absorptiometry. Blood samples were collected from all subjects for measurement of RANKL, OPG, the bone formation marker bone-specific alkaline phosphatase (BAP), the bone resorption marker tartrate-resistant acid phosphatase-5b (TRAP-5b), total antioxidant capacity (TAOC). Twenty-eight severe OSAHS patients accepted continuous positive airway pressure (CPAP) treatment voluntarily. After 6 months, PSG was conducted, and serum RANKL, OPG, TAOC, TRAP-5b, BAP was measured after six months treatment. Results The BMD, T-score of the femoral neck and the lumbar spine were significantly lower in OSAHS patients as compared to the control group. The level of BAP was significantly decreased in the OSAHS group as compared to the control group, and there was no significant difference in TRAP-5b level between two groups. As compared with the control group, levels of OPG, TAOC and the OPG/RANKL ratio decreased significantly. None of these parameters (BMD, T-score, RANKL, OPG, TRAP-5b, BAP) showed significant difference between patients with mild-moderate and severe OSAHS group. Correlation analysis showed that the apnea hypopnea index and oxygen desaturation index were correlated with TAOC. BAP level was positively correlated with TAOC and lowest pulse oxygen saturation. The serum level of TAOC was lower in the OSAHS group after CPAP therapy, but the levels of RANKL, OPG, TRAP-5b, BAP were not different. As compared with the OSAHS group before CPAP therapy, the BMD of the femoral neck and the lumbar spine were not significant difference. Conclusions In patients with OSAHS, the oxidative stress response is enhanced, and imbalance of OPG/RANKL is shifted, which participates in the occurrence of osteoporosis. The oxidative stress injury of severe OSAHS patients was relieved after non-invasive ventilation treatment, but the effect of oxidative stress response on bone metabolism still needs further evaluation.