一氧化氮吸入对羊感染性急性呼吸窘迫综合征血液动力学和肺氧合功能的影响

目的：探讨一氧化氮（NO）吸入对羊感染性急性呼吸窘迫综合征（ARDS）血流动力学和肺氧合功能的影响。方法：静脉注入小剂量内毒素诱导羊感染性ARDS模型。随机分为两组：（1）NO组（n=6）为ARDS建立后，在容量控制通气基础上持续吸入40ppmNO 3h；（2）对照组（n=6)为ARDS一单纯容量控制通气，观察3h以确定模型的稳定性并与NO组比较，通过肺动脉导管和动脉血气分析，测定各组每小时肺气体交换和血流动力学参数，3h结束实验时，检测血中高铁血红蛋白（MetHb）浓度。结果：静脉注入小剂量内毒素能够诱导稳定的羊感染性ARDS模型，该模型的平均肺动脉压（MPAP）较基础值明显升高（P＜0．01），体循环血液动力学则能维持稳定。NO组各时点MPAP均较治疗前和同时点的对照组低（P＜0．01），动脉氧分压（PaO2）则明显增加（P＜0．01），肺泡动脉血氧分压差（PA－aO2)和肺内分流（Qs/Qt)明显低于治疗前和同时点的对照组（P＜0．01）。两组平均动脉压（MAP）和心排量（CO）各时点及治疗前后比较均无明显变化（P＞0．05），MetHb未见明显升高，结论：吸入NO选择性降低肺动脉压，改善肺氧合，无明显毒副作用。     

Improved oxygenation utilizing a prone positioner in patients with acute respiratory distress syndrome

Objectives (a) To determine whether placing patients with acute respiratory distress syndrome in the prone position by a light-weight portable support frame improves oxygenation, (b) whether one can determine which patients benefit from prone positioning, and (c) to determine an effective technique for prone positioning of patients.Design Prospective, controlled trial without blinding.Setting Medical intensive care units in two urban university-affililated hospitals.Patients Fifteen patients meeting a standard definition for acute respiratory distress syndrome were studied prospectively. Each patient acted as his own control for purposes of comparison.Intervention Patients were assigned randomly to begin in either supine or prone positions. The positioning frame was used to turn patients from one position to the other, and oxygenation, ventilation, respiratory mechanics, and hemodynamics were measured.Results Significantly better oxygenation was seen in the prone positions than in the supine (P<0.05). In the overall population there was a decrease in AaDO₂ of 21 mmHg when the patients were placed prone. The groups were then divided into responders (n=9) and nonresponders (n=6). There were significant differences between the groups (but not between positions) regarding PaO₂, baseline, PaCO₂, pulmonary artery pressures, and peak inspiratory pressures on the ventilator and in ICU length of stay and time on mechanical ventilatory support.Conclusion Prone positioning improves oxygenation in the majority of patients studied and can be achieved relatively easily.     

俯卧位通气对急性肺损伤和急性呼吸窘迫综合征临床疗效影响的Meta分析

目的 系统评价俯卧位通气(PPV)对我国急性肺损伤(ALI)和急性呼吸窘迫综合征(ARDS)患者的短期临床疗效.方法 利用Cochrane系统评价法,全面检索2000年至2009年国内公开发表的所有ALI与ARDS患者PPV的临床研究资料.对纳入研究独立进行质量评价、资料提取、交叉核对后行Meta分析.结果 纳入研究8项共184例患者,PPV时患者动脉血氧分压(PaO2)、氧合指数(PaO2/FiO2)、呼吸系统总顺应性(C)均显著升高;动脉血二氧化碳分压(PaCO2)、中心静脉压(CVP)、呼吸道峰压(PIP)和呼吸系统总阻力(Raw)无显著的变化;心率(HR)与平均动脉压(MAP)显著升高. 结论 ALI与ARDS患者行PPV可增加呼吸系统总顺应性,改善患者低氧血症,相关临床研究结果基本一致.但因Meta分析的自身局限性,我们仍急需开展设计严谨的高质量大样本临床研究,明确PPV临床疗效、作用机制、科学的操作流程及PPV对患者血流动力学的影响等临床实际问题,改善国内ALI与ARDS患者的临床护理水平.     

急性呼吸窘迫综合征患者侧卧位通气与俯卧位通气的临床疗效观察

目的 评价侧卧位通气和俯卧位通气对急性呼吸窘迫综合征（ARDS）患者的临床疗效。并对两种体位通气方法进行对比观察。方法 将ICU2005年收治的23例ARDS患者随机分为两组，分别施行侧卧位通气（15例）和俯卧住通气（8例），监测仰卧位时，体位改变后1、2、4h及转复为仰卧位后1h的呼吸循环指标，并分别进行比较。结果 体位改变后1、2、4h及转复为仰卧住后1h，两组患者动脉血氧分压、氧舍指数均较仰卧位时升高（P〈0．05），心率、平均动脉压、气道峰压及动脉血二氧化碳分压与仰卧位时比较差异无统计学意义（P〉0．05）。以氧分压升高10mmHg为有效标准。治疗有效率侧卧位组73．3％，俯卧位组66．7％，两组比较差异无统计学意义（P〉0．05）。结论 作为ARDS机械通气治疗手段，侧卧位通气与俯卧位通气治疗的有效率接近。但侧卧位实施更容易，护理更方便。并发症少，值得临床进一步探讨。     

两种俯卧位角度对急性呼吸窘迫综合征机械通气患者临床指标的影响

目的比较10°和25°头高足低俯卧位通气角度对急性呼吸窘迫综合征(ARDS)患者氧合指标、血流动力学、压力性损伤发生率、VAP发生率的影响。方法将2020年4月—2021年4月医院收治的ARDS患者,按组间特征具有可比性的原则分为观察组25例和对照组26例。对照组患者给予10°头高足低俯卧位,观察组患者给予25°头高足低俯卧位,观察比较两组俯卧位动脉血氧分压(PaO₂)、二氧化碳分压(PaCO₂)、氧合指数(PaO₂/FiO₂)、血流动力学指标、压力性损伤发生率、VAP的发生情况。结果俯卧位后两组氧合指标、心率等较俯卧位前均有改善,但两指标组间比较差异无统计学意义(P>0.05)。观察组患者压力性损伤发生率及VAP发生率低于对照组,差异有统计学意义(P<0.05)。结论ARDS患者取25°头高足低俯卧位通气既可以有效改善氧合,也可以降低患者压力性损伤及VAP发生率,是ARDS患者行机械通气时较合适的体位。     

Extended prone position ventilation in severe acute respiratory distress syndrome: A pilot feasibility study

Objectives

The aim of the study was to evaluate the safety of extended prone position ventilation (PPV) and its impact on respiratory function in patients with severe acute respiratory distress syndrome (ARDS).

Design

This was a prospective interventional study.

Setting

Patients were recruited from a mixed medical-surgical intensive care unit in a university hospital.

Patients

Fifteen consecutive patients with severe ARDS, previously unresponsive to positive end-expiratory pressure adjustment, were treated with PPV.

Intervention

Prone position ventilation for 48 hours or until the oxygenation index was 10 or less (extended PPV).

Results

The elapsed time from the initiation of mechanical ventilation to pronation was 35 ± 11 hours. Prone position ventilation was continuously maintained for 55 ± 7 hours. Two patients developed grade II pressure ulcers of small extent. None of the patients experienced life-threatening complications or hemodynamic instability during the procedure. The patients showed a statistically significant improvement in Pao₂/Fio₂ (92 ± 12 vs 227 ± 43, P < .0001) and oxygenation index (22 ± 5 vs 8 ± 2, P < .0001), reduction of PaCo₂ (54 ± 9 vs 39 ± 4, P < .0001) and plateau pressure (32 ± 2 vs 27 ± 3, P < .0001), and increment of the static compliance (21 ± 3 vs 37 ± 6, P < .0001) with extended PPV. All the parameters continued to improve significantly while they remained in prone position and did not change upon returning the patients to the supine position.

Conclusions

The results obtained suggest that extended PPV is safe and effective in patients with severe ARDS when it is carried out by a trained staff and within an established protocol. Extended PPV is emerging as an effective therapy in the rescue of patients from severe ARDS.     

Efficacy of prone position in acute respiratory distress syndrome patients: A pathophysiology-based review

Acute respiratory distress syndrome (ARDS) is a syndrome with heterogeneous underlying pathological processes. It represents a common clinical problem in intensive care unit patients and it is characterized by high mortality. The mainstay of treatment for ARDS is lung protective ventilation with low tidal volumes and positive end-expiratory pressure sufficient for alveolar recruitment. Prone positioning is a supplementary strategy available in managing patients with ARDS. It was first described 40 years ago and it proves to be in alignment with two major ARDS pathophysiological lung models; the “sponge lung” - and the “shape matching” -model. Current evidence strongly supports that prone positioning has beneficial effects on gas exchange, respiratory mechanics, lung protection and hemodynamics as it redistributes transpulmonary pressure, stress and strain throughout the lung and unloads the right ventricle. The factors that individually influence the time course of alveolar recruitment and the improvement in oxygenation during prone positioning have not been well characterized. Although patients’ response to prone positioning is quite variable and hard to predict, large randomized trials and recent meta-analyses show that prone position in conjunction with a lung-protective strategy, when performed early and in sufficient duration, may improve survival in patients with ARDS. This pathophysiology-based review and recent clinical evidence strongly support the use of prone positioning in the early management of severe ARDS systematically and not as a rescue maneuver or a last-ditch effort.     

Clinical evaluation of prone position ventilation in the treatment of acute respiratory distress syndrome induced by sepsis

BACKGROUNDAcute respiratory distress syndrome (ARDS) is an acute, diffuse, inflammatory lung injury. Previous studies have shown prone position ventilation (PPV) to be associated with improvement in oxygenation. However, its role in patients with ARDS caused by sepsis remains unknown. AIMTo analyze the clinical effects of PPV in patients with ARDS caused by sepsis. METHODSOne hundred and two patients with ARDS were identified and divided into a control group (n = 55) and a PPV treatment group (n = 47). Outcomes included oxygenation index, lung compliance (Cst) and platform pressure (Pplat), which were compared between the two groups after ventilation. Other outcomes included heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), left ventricular ejection fraction (LVEF), the length of mechanical ventilation time and intensive care unit (ICU) stay, and levels of C-reactive protein (CRP), procalcitonin (PCT), and interleukin-6 (IL-6) after ventilation. Finally, mortality rate was also compared between the two groups. RESULTSOn the first day after ventilation, the oxygenation index and Cst were higher and Pplat level was lower in the PPV group than in the conventional treatment group (P < 0.05). There were no significant differences in oxygenation index, Cst, and Pplat levels between the two groups on the 2^nd, 4^th, and 7^th day after ventilation (P > 0.05). There were no significant differences in HR, MAP, CVP, LVEF, duration of mechanical ventilation and ICU stay, and the levels of CRP, PCT, and IL-6 between the two groups on the first day after ventilation (all P > 0.05). The mortality rates on days 28 and 90 in the PPV and control groups were 12.77% and 29.09%, and 25.53% and 45.45%, respectively (P < 0.05). CONCLUSIONPPV may improve respiratory mechanics indices and may also have mortality benefit in patients with ARDS caused by sepsis. Finally, PPV was not shown to cause any adverse effects on hemodynamics and inflammation indices.     

Effectiveness of prone position in acute respiratory distress syndrome and moderating factors of obesity class and treatment durations for COVID-19 patients: A meta-analysis

ObjectivesTo examine the effectiveness of prone positioning on COVID-19 patients with acute respiratory distress syndrome with moderating factors in both traditional prone positioning (invasive mechanical ventilation) and awake self-prone positioning patients (non-invasive ventilation).Research methodologyA comprehensive search was conducted in CINAHL, Cochrane library, Embase, Medline-OVID, NCBI SARS-CoV-2 Resources, ProQuest, Scopus, and Web of Science without language restrictions. All studies with prospective and experimental designs evaluating the effect of prone position patients with COVID-19 related to acute respiratory distress syndrome were included. Pooled standardised mean differences were calculated after prone position for primary (PaO₂/FiO₂) and secondary outcomes (SpO₂ and PaO₂)ResultsA total of 15 articles were eligible and included in the final analysis. Prone position had a statistically significant effect in improving PaO₂/FiO₂ with standardised mean difference of 1.10 (95%CI 0.60–1.59), SpO₂ with standardised mean difference of 3.39 (95% CI 1.30–5.48), and PaO₂ with standardised mean difference of 0.77 (95% CI 0.19–1.35). Patients with higher body mass index and longer duration/day are associated with larger standardised mean difference effect sizes for prone positioning.ConclusionsOur findings demonstrate that prone position significantly improved oxygen saturation in COVID-19 patients with acute respiratory distress syndrome in both traditional prone positioning and awake self-prone positioning patients. Prone position should be recommended for patients with higher body mass index and longer durations to obtain the maximum effect.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

俯卧位通气对静脉-静脉体外膜肺氧合支持的急性呼吸窘迫综合征患者病死率影响的Meta分析

目的系统评价俯卧位通气对静脉-静脉体外膜肺氧合（VV-ECMO）支持的急性呼吸窘迫综合征（ARDS）患者病死率的影响。 方法计算机检索Medline、荷兰医学文摘Embase、Cochrane临床试验数据库、万方数据库及中国知网数据库从2002年1月至2022年1月关于VV-ECMO支持ARDS期间使用俯卧位通气的随机对照研究或观察性研究。试验组为俯卧位通气患者,对照组为仰卧位通气患者。由2名研究人员独立进行筛选文献、提取文献资料及评估方法学质量后,采用RevMan 5.3软件进行Meta分析。 结果最终纳入14项研究,共计1 880例患者,其中试验组869例,对照组1 011例。Meta分析显示,与对照组比较,试验组VV-ECMO支持的ARDS患者的28 d病死率[相对危险度（RR）=0.59,95%置信区间（CI）（0.43,0.80）,Z = 3.41,P = 0.000 7]及住院病死率[RR = 0.73,95%CI（0.66,0.81）,Z = 5.86,P < 0.000 01]均显著降低;但两组患者间其他病死率（30 d、60 d、90 d、ICU、6个月病死率）的比较,差异无统计学意义[RR = 0.80,95%CI（0.61,1.05）,Z = 1.60,P = 0.11]。 结论俯卧位通气能够降低VV-ECMO支持的ARDS患者28 d病死率以及住院病死率。     

俯卧位通气联合一氧化氮吸入对急性呼吸窘迫综合征患者氧合的影响

目的 评价俯卧位通气(PPV)联合NO吸入对急性呼吸窘迫综合征(ARDS)患者氧合的影响.方法 将我院重症医学科2008年9月至2011年1月收治的,应用最佳PEEP后仍需较高的吸入氧体积分数(FIO2≥60％)的21例ARDS患者,随机(随机数字法)分为三组进行对照研究.A组采取单纯NO吸入4h;B组采取俯卧位通气2h,2h后恢复仰卧位通气;C组采取俯卧位通气联合NO吸入2h,2h后恢复仰卧位通气并继续吸入NO.分别测三组患者治疗干预前、2h及4h氧合指数.统计学处理采用SPSS 13软件,数据以均数±标准差(-x±s)表示,组间比较用单因素方差分析,组内比较用t检验,P ＜0.05为差异有统计学意义.结果 与治疗干预前比较,三组患者2h后氧合指数均较前改善,但A组患者差异无统计学意义(P＞0.05),B组和C组患者差异有统计学意义(P ＜0.05);4h后A组和B组氧合指数跟治疗干预前比较无显著差异(P＞0.05),C组氧合指数仍保持改善(P＜0.05).结论 俯卧位通气可以有效地改善严重ARDS患者氧合,俯卧位通气联合NO吸入不但可以改善氧合,而且恢复仰卧位后能有效的维持氧合,因此卧位通气联合NO吸入的方法在改善氧合的同时能减少俯卧位通气时间.     

俯卧位机械通气在急性呼吸窘迫综合症患者中的应用状况

急性呼吸窘迫综合征（acuterespiratorydistresssyndrome,ARDS）是指肺内、外严重疾病导致以肺毛细血管弥漫性损伤、通透性增强为基础,以肺水肿、透明膜形成和肺不张为主要病理变化,以进行性呼吸窘迫和难治性低氧血症为临床特征的急性呼吸衰竭综合征。ARDS是急性肺损伤（acutelunginjury,ALI）发展到后期的典型表现。该病起病急骤,发展迅猛,预后极差,     

急性呼吸窘迫综合征在肺灌洗后行俯卧位通气的疗效观察

目的观察急性呼吸窘迫综合征患者在肺灌洗后行俯卧位通气治疗对氧合、肺力学的影响及作用。方法20例急性呼吸窘迫综合征患者在肺灌洗后行俯卧位通气治疗,分别监测治疗前、治疗后的氧分压、气道峰压、炎症介质的变化,观察治疗前后患者胸部CT影像学的变化。结果经过肺灌洗和俯卧位通气2 h后氧分压明显升高、气道峰压显著下降,俯卧位通气1 d后胸部CT检查显示肺实变区部分消失,炎症介质检验显示明显下降。结论肺灌洗后行俯卧位通气可改善早期急性呼吸窘迫综合征患者的氧合,有效改善肺部炎症。     

连续性高容量血液滤过治疗重度急性呼吸窘迫综合征的临床疗效

目的 探讨连续性高容量血液滤过(CHVHF)治疗重度急性呼吸窘迫综合征(ARDS)的临床疗效.方法 采用前瞻性随机对照研究方法,选择2007年6月至2011年6月入住本院重症监护病房(ICU)的65例重度ARDS患者进行研究,按照随机数字表法分为治疗组(37例)和对照组(28例),对照组给予常规治疗,治疗组在常规治疗基础上应用CHVHF治疗.观察两组患者治疗前及治疗后6、24、48、72 h肺功能指标氧合指数(PaO2/FiO2)、血管外肺水指数(EVLWI)、动脉血二氧化碳分压(PaCO2),以及血流动力学参数如心率(HR)、平均动脉压(MAP)的变化,并观察机械通气的持续时间、住ICU天数、撤机成功率、28 d存活率等指标.结果 两组治疗后肺功能指标较治疗前均有明显改善,随治疗时间延长PaO2/FiO2(mm Hg,1 mm Hg=0.133kPa)逐渐升高,EVLWI (ml/kg)、PaCO2(mm Hg)逐渐下降,且治疗组较对照组改善明显(6 h PaO2/FiO2:92.6±7.2比83.8±11.4,24 h EVLWI:10.8±3.7比12.6±4.5,24 h PaCO2:47.2±8.5比51.4±4.8,均P＜0.05).两组治疗后血流动力学指标HR、MAP较治疗前明显改善,但两组间比较差异无统计学意义.与对照组比较,治疗组机械通气时间(d)、住ICU天数(d)明显缩短(机械通气时间:12±4比19±6,住ICU天数:21±4比33±8,均P＜0.05),撤机成功率、28 d存活率明显升高(撤机成功率:81.1％比64.3％,28 d存活率:86.5％比71.4％,均P＜0.05).结论 重度ARDS患者采用CHVHF治疗能明显改善肺功能,缩短机械通气时间,提高机械通气撤机成功率,降低病死率,对血流动力学无明显不利影响.     

Long-term inhalation with evaluated low doses of nitric oxide for selective improvement of oxygenation in patients with adult respiratory distress syndrome

Objective To evaluate the lowest dose of inhaled nitric oxide (NO) in patients with adult respiratory distress syndrome (ARDS), which is able to improve arterial oxygenation more than 30% compared to baseline data.Design Prospective, clinical study.Setting Anesthesiological ICU in a university hospital.Patients 3 consecutive patients with severe ARDS according to clinical and radiological signs.Interventions Pressure-controlled ventilation with positive endexpiratory pressure of 8–12 cm H₂O. Inhalation of NO was performed with a blender system and a Servo 300 ventilator. The lowest effective NO dose was defined by titrating the inspiratory NO dose until reaching a 30% improvement of PaO₂/FiO₂. This dose was used for the following continuous long-term NO inhalation; controls of efficacy by investigation of hemodynamics and blood gas exchange were performed initially and 2 times per patient after intervals of 3–5 days.Measurements and results Initial NO concentrations were found to be effective at 60, 100, and 230 parts per billion (ppb). In all measurements, arterial oxygenation was found to be elevated by NO inhalation with the initially evaluated dose compared to baseline data; in parallel, the venous admixture was reduced. The O₂ delivery increased, although O₂ consumption and hemodynamics did not change. In 1 patient, interruption of NO inhalation caused remarkable increase of pulmonary resistance.Conclusions The improvement of oxygenation by NO inhalation in ARDS does not require reduction of pulmonary resistance and can be performed using low doses in the ppb range, which has to be considered as probably non-toxic.The studies were supported by the Deutsche Forschungsgesellschaft (DFG), Grants Fa 139/1-3 and Fa 139/2-3. Dr. H. Gerlach completed this work during the tenure of a VTG Scientific Award     

Hemodynamic and gas exchange responses to inhalation of nitric oxide in patients with the acute respiratory distress syndrome and in hypoxemic patients with chronic obstructive pulmonary disease

Objective: Inhalation of nitric oxide (NO) can improve oxygenation and decrease mean pulmonary artery pressure (MPAP) in patients with the acute respiratory distress syndrome (ARDS). It is not known whether inhaled NO exerts a similar effect in hypoxemic patients with chronic obstructive pulmonary disease (COPD). Design: Prospective clinical study. Setting: General intensive care unit in Sabadell, Spain. Patients: Nine mechanically ventilated COPD patients (mean age 72±2 years; forced expiratory volume in 1 s 0.91±0.11 l) and nine ARDS patients (mean age 57±6 years; mean lung injury score 2.8±0.1) Measurements and results: We measured hemodynamic and gas exchange parameters before NO inhalation (basal 1), during inhalation of 10 ppm NO (NO-10), and 20 min after NO was discontinued (in basal 2) in the ARDS group. In the COPD group, these parameters were measured before NO inhalation (basal 1), during different doses of inhaled NO (10, 20, and 30 ppm), and 20 min after NO was discontinued (basal 2). A positive response to NO was defined as a 20% increment in basal arterial partial pressure of oxygen (PaO₂). MPAP and pulmonary vascular resistance (PVR) decreased significantly, while other hemodynamic parameters remained unchanged after NO-10 in both groups. Basal oxygenation was higher in the COPD group (PaO₂/FIO₂ (fractional inspired oxygen) 190±18 mmHg) than in the ARDS group (PaO₂/FIO₂ 98±12 mmHg), (p<0.01). After NO-10, PaO₂/FIO₂ increased (to 141±17 mmHg, p<0.01) and Qva/Qt decreased (39±3 to 34±3%, p<0.01) in the ARDS group. There were no changes in PaO₂/FIO₂ and Qva/Qt when the NO concentration was increased to 30 ppm in the COPD group. In both groups, a correlation was found between basal MPAP and basal PVR, and between the NO-induced decrease in MPAP and in PVR. The NO-induced increase in PaO₂/FIO₂ was not correlated with basal PaO₂/FIO₂. In the ARDS group, six of the nine patients (66%) responded to NO and in the COPD group, two of nine (22%) (p=0.05). Conclusions: NO inhalation had similar effects on hemodynamics but not on gas exchange in ARDS and COPD patients, and this response probably depends on the underlying disease. Received: 19 December 1995 Accepted: 28 September 1996     

俯卧位通气联合呼气末正压治疗急性呼吸窘迫综合征家猪的疗效研究

目的 探讨俯卧位通气联合呼气末正压(PEEP)治疗急性呼吸窘迫综合征(ARDS)的疗效及其机制.方法 12头家猪静脉注射油酸建立ARDS模型,分为仰卧位组和俯卧位组,均给予0(ZEEP)、10(PEEP10)、20 cm H2O(PEEP20,1 cm H2O=0.098 kPa)PEEP的机械通气15 min,监测家猪血流动力学、肺气体交换和呼吸力学指标;处死动物观察肺组织病理学变化.结果 俯卧位组ZEEP、PEEP10时氧合指数(PaO2/FiO2)明显优于仰卧位组[ZEEP:(234.00±72.55)mm Hg比(106.58±34.93)mm Hg,PEEP10:(342.97±60.15) mm Hg比(246.80±83.69)mm Hg,1 mm Hg=0.133 kPa,P均<0.05];PEEP20时两组PaO2/FiO2差异无统计学意义(P>0.05).PEEP10时两组肺复张容积(RV)差异无统计学意义(P>0.05);但PEEP20时俯卧位组RV显著高于仰卧位组[(378.55±101.80)ml比(302.95±34.31)ml,P<0.05].两组间心率(HR)、平均动脉压(MAP)、心排血指数(CI)、呼吸系统顺应性(Cst)及动脉血二氧化碳分压(PaCO2)差异均无统计学意义(P均>0.05);仰卧位组背侧肺组织的肺损伤总评分明显高于俯卧位组[(12.00±1.69)分比(6.03±1.56)分,P<0.05].结论 俯卧位通气联合合适的PEEP可改善ARDS家猪氧合,并且不影响血流动力学和呼吸力学,肺组织损伤的重新分布可能是其机制之一.     

一氧化氮吸入治疗新生儿呼吸窘迫综合征临床观察

目的观察一氧化氮(NO)吸入对新生儿呼吸窘迫综合征(NRDS)治疗作用及其有关影响因素。方法将49例NRDS患儿随机分为两组,对照组24例,采用综合治疗、肺表面活性物质(PS)替代疗法及氧疗等常规治疗;吸入NO(iNO)组25例,在常规治疗基础上加用NO吸入治疗,NO与机械通气同步使用,吸入浓度从10ppm开始,最高不超过30ppm,持续吸入时间24~36h,同时动态观察血气主要指标的变化。结果治疗后(24h)pH、PaO2、PaCO2、PaO2/FiO2、SaO2及肺泡动静脉氧分压差(A-a)PO26项血气指标的改善,iNO组优于对照组(P<0.01或0.05);iNO组在治疗后不同时期(1、12、24及36h)6项血气指标均有较好改善,与治疗前相比,除治疗后1h差异无统计学意义(P>0.05)外,治疗后12、24及36h各项指标差异均有统计学意义(P<0.05或0.01),且血气指标改善情况与吸入时间相关;iNO组在治愈率、死亡率及并发症发生率等转归方面均优于对照组(均P<0.05)。结论吸入NO治疗NRDS,尤其是重症和早产患儿,能够显著改善氧合功能,增加通气/血流比值,从而明显缓解临床症状,改善患儿的预后。对吸入NO的最有效时间,尚需进一步研究。