机械通气患者人工气道囊内压对呼气末正压的影响分析

正压通气加呼气末正压(PEEP)通气策略是抢救危重患者特别是呼吸功能障碍患者的常用治疗方法,已被广泛应用于临床.气管导管气囊充气不仅保证了正压通气的有效实施,而且阻挡了口鼻咽部分泌物下行产生误吸导致的呼吸机相关性肺炎(VAP)发生[1].     

呼气末正压及持续气道正压治疗心源性肺水肿

我们应用呼气末正压(PEEP)及持续气道正压(CPAP)治疗2例心源性肺水肿,使患者转危为安,现结合文献讨论如下。     

呼气末正压对机械通气病人中心静脉压的影响

目的：评价呼气末正压（PEEP）如何影响机械通气病人的中心静脉压（CVP）。方法：监测40例机械通气病人在不同水平PEEP（0－20cmH2O）时的CVP值，同时记录心率，平均动脉压、血氧饱和度，统计学处理所有计量资料以及CVP与PEEP的相关性分析。结果：CVP值随PEEP值的增加而增高，且CVP值的变化与PEEP值的变化呈显著性正相关，r=0.9908，结论：虽然机械通气时CVP值受PEEP的影响而增高，但监测CVP仍可作为指导机械通气病人液体治疗的有效方法。     

机械通气病人应用呼气末正压对膀胱压的影响

[目的]探讨机械通气病人应用呼气末正压(PEEP)对膀胱压的影响。[方法]选择重症监护病房(ICU)行机械通气并监测膀胱压的病人58例,应用自身对照法,观察病人在暂时脱离呼吸机及PEEP 0cmH2O、3cmH2O、6cmH2O、9cmH2O、12cmH2O和15cmH2O时的膀胱压变化。[结果]不同PEEP状态下膀胱压变化差异有统计学意义(P<0.05),其中呼气末正压为0cmH2O、3cmH2O时与脱离呼吸机测得的膀胱压比较差异无统计学意义(P>0.05)。[结论]测量膀胱压时,可维持原有≤3cmH2O的PEEP值,以保证病人氧合,增加病人的安全性和舒适性。     

呼气末正压治疗重症哮喘的临床观察

观察呼气末正压对重症哮喘患者的治疗作用。方法：通过观察不同水平ＰＥＥＰ对重症哮喘患者气道压力和动脉血氧分压及二氧化碳分压的影响,明确ＰＥＥＰ对重症哮喘的治疗作用。结果：应用ＰＥＥＰ后患者呼吸困难明显好转,气道阻力明显降低,ＰＥＥＰ水平在１．３７－１．９６ｋＰａ之间逐渐增加时,上述症状更为明显缓解;ＰａＣＯ２明显降低,而ＰａＯ２显著升高。结论ＰＥＥＰ是治疗重症哮喘的有效方法之一。     

最佳呼气末正压

呼气末正压（ＰＥＥＰ）已成为治疗急性呼吸窘迫综合征（ＡＲＤＳ）的重要手段。ＰＥＥＰ有效的作用机制主要包括：①防止肺泡塌陷和肺不张，使塌陷肺泡重新复张，增加功能残气量（ＦＲＣ），增加气体交换面积，减少肺内水分，改善肺顺应性（ＣＰ），提高肺功能；②改善通...     

呼气末正压通气对冠脉搭桥术后机械通气时间的影响

目的：分析不同等级的呼气末正压通气( PEEP)值对冠脉搭桥术后机械通气时间的差异。方法回顾性收集苏州市某三级医院2013年1—11月进行冠脉搭桥84例患者的资料,根据呼气末正压值不同分为三组,PEEP值等于5 cmH2O为A组(n=26),PEEP值等于8 cmH2O为B组(n=28),PEEP值等于10 cmH2O为C组(n=30)。从护理记录中获取三组患者的机械通气时间并进行比较。结果术后入住ICU病房12 h内即拔管的患者中,A组机械通气时间为(7.3±2.4) h,B组为(7.6±2.7) h,C组为(6.8±3.2)h,各组机械通气时间差异有统计学意义(F=23.15,P<0.05)。结论冠脉搭桥术后选择合适的PEEP值有利于缩减冠脉搭桥患者的术后机械通气时间。     

呼气末正压通气在急性肺水肿中的作用

目的:探讨呼气末正压机械通气在救治肺水肿中的作用。方法:对22例肺水肿患者在常规氧疗效果不理想的情况下,进行机械通气并加用呼吸末正压(PEEP)治疗。结果:21例患者在24h内气促明显缓解,3至5d内肺水肿完全消失。结论:机械通气加用PEEP是救治肺水肿的最有效方法之一。     

机械通气时脱机与关闭呼气末正压对中心静脉压的影响比较

目的 探讨机械通气时断开呼吸机前后及关闭呼气末正压(PEEP)前后,脱机与关闭PEEP对中心静脉压(CVP)的影响,提高机械通气病人CVP测量的准确性.方法 对60例机械通气病人脱机前后及关闭PEEP前后进行CVP参数的监测.结果 经监测比较发现,脱机与关闭PEEP前均比脱机与关闭PEEP后的CVP测量值高,脱机与关闭PEEP的CVP测量值比较有显著差异.结论 建议对于机械通气病人在确保安全的情况下测量CVP时,应尽可能的断开呼吸机进行,以确保机械通气病人CVP测量的准确性,为临床治疗提供准确的依据.     

体位及呼气末正压对危重病患者中心静脉压的影响

目的观察不同体位及呼气末正压(PEEP)水平对机械通气(MV)危重患者中心静脉压(CVP)的影响。方法选择2005年12月—2006年3月重症加强治疗病房(ICU)进行MV并监测CVP的患者23例,观察患者在30°卧位及平卧位时PEEP0、3、6、9、12和15cmH2O(1cmH2O=0.098kPa)条件下CVP、心率(HR)、平均动脉压(MAP)、脉搏血氧饱和度(SpO2)及Riker镇静-躁动评分(SAS)的变化。结果相同PEEP条件下,患者两种体位的CVP、HR及MAP均无明显变化(P均>0.05);30°卧位SpO2显著高于平卧位(P<0.01)。患者体位由30°卧位调至平卧位及固定体位脱机时,CVP随PEEP水平升高而递增,至PEEP15cmH2O时明显高于其他PEEP水平(P均<0.05);脱机时SpO2明显低于不同PEEP水平时(P均<0.05);SAS随PEEP水平升高而递减,至PEEP15cmH2O时,SAS有所升高(P均<0.05);HR和MAP无明显变化。结论体位改变对MV患者的CVP无明显影响,随PEEP水平增加,CVP逐渐增加;改变体位与脱机均会使患者缺氧加重、躁动增加;维持患者原体位及PEEP水平而测量CVP,可增加患者的安全性与舒适性,减少医护人员工作量。     

Effects of positive end-expiratory pressure on hyaline membrane formation in a rabbit model of the neonatal respiratory distress syndrome

Sixteen rabbits were anaesthetized and subjected to saline lavage of the lungs to produce surfactant deficiency. This resulted in an arterial oxygen tension of less than 12 kPa on 100% inspired oxygen and an inflection point on the pressure-volume curve at a pressure of 8–12 mmHg. After lavage the animals were randomly assigned to receive either conventional mechanical ventilation (CMV) with a positive end-expiratory pressure (PEEP) of 1–2 mmHg (group I —low PEEP) or CMV with PEEP equal to the inflection point pressure (group II — high PEEP). Mean airway pressures were kept at 14–16 mmHg in both groups by increasing the inspiratory: expiratory time ratios in the low PEEP group. The 5-h protocol was completed by 4 animals in group I and 6 animals in group II, early death usually being associated with a metabolic acidosis. On 100% oxygen, the mean PaO₂ at 2-h post-lavage was 15.2±8.3 kPa in group I and 39.6±21.8 kPa in group II. Group I had much lower end-expiratory lung volumes (3.0±1.5 ml above FRC) than group II (34.9±12.2 ml above FRC). Histological examination of the lungs revealed significantly less hyaline membrane formation in group II (p=0.001). Thus, the prevention of alveolar collapse by the use of high PEEP levels appears to reduce lung damage in this preparation.     

Continuous positive airway pressure (CPAP) vs. intermittent mandatory pressure release ventilation (IMPRV) in patients with acute respiratory failure

Intermittent Mandatory Pressure Release Ventilation (IMPRV) is a positive pressure spontaneous breathing ventilatory mode in which airway pressure is released intermittently and synchronously with patient's spontaneous expiration in order to provide ventilatory assistance. Eight critically ill patients free of any factor known to alter chest wall mechanics (group 1) and 8 critically ill patients whose spontaneous respiratory activity was markedly altered by a flail chest, or by a C₅ quadraplegia and/or by the administration of opioids (group 2) were studied prospectively. CPAP and IMPRV were administered to each patient in a random order during a 1 h period using a CESAR ventilator. Gas flow, tidal volume, tracheal pressure, esophageal pressure, end-expiratory lung volume and hemodynamic parameters were measured. In group 1 patients, the ventilatory assistance provided by IMPRV was associated with a significant decrease in spontaneous tidal volume whereas all other respiratory parameters remained unchanged. In group 2 patients, IMPRV increased minute ventilation from 8.0±2.61/min to 12.2±1.81/min (p<0.05), decreased PaCO₂ from 46±7.3 mmHg to 38±6.8 mmHg (p<0.05) and reduced respiratory frequency from 21±10 bpm to 14±5.7 bpm (p<0.07). These results show that IMPRV provides significant ventilatory assistance to patients with mild acute respiratory failure either by decreasing patient's contribution to minute ventilation or by increasing alveolar ventilation in presence of respiratory depression of central or peripheral origin.Presented in part at the 32th Congrès National d'Anesthésie-Réanimation, Paris, September, 24, 1990 and at the Annual Meeting of the American Society of Anesthesiologists, Las Vegas, Nevada, October 22, 1990     

呼气末正压通气对重型颅脑损伤患者中心静脉压的影响

目的 观察呼气末正压(PEEP)对重型颅脑损伤机械通气患者中心静脉压(CVP)的影响.方法 采用前瞻性自身对照研究方法,选择30例需机械通气的重型颅脑损伤伴中枢性呼吸衰竭患者,在不同PEEP水平(0、3、6、9、12、15 cmH2O,1cm H2O=0.098 kPa)通气条件下及脱机时,监测CVP、平均动脉压(MAP)、心率(HR)和脉搏血氧饱和度( SpO2)的变化,分析带机加PEEP及脱机对CVP等血流动力学指标及氧合功能的影响.结果 CVP检测值(cm H2O)随PEEP升高逐渐升高(7.9±3.1～13.1±3.7),呈直线正相关(R=0.509,P=0.000),线性回归方程为CVP(cm H2O) =7.774+ 0.368×PEEP(cm H2O),PEEP每增加1 cm H2O、CVP增加约0.368cmH2O;与不同PEEP水平比较,脱机时CVP检测值明显下降(F=24.429,P=0.000).在不同PEEP水平时,MAP、HR和SpO2无显著差异[MAP( mm Hg,1 mm Hg=0.133 kPa):81.6±10.4～ 85.6±10.6;HR(次/min):79.9±13.5～88.1±15.4;SpO2:0.968±0.036 ～ 0.975±0.033,均P＞0.05];但脱机时MAP和HR均显著升高(分别为95.3±8.4和94.9±10.3),而SpO2明显降低(0.928±0.036,均P=0.000).结论 PEEP可使重型颅脑损伤机械通气患者CVP检测值偏高,PEEP每增加1cmH2O,CVP增加约0.368 cm H2O; MAP、HR和SpO2随PEEP改变无明显变化.该结果可为准确评估带机检测CVP提供理论依据.     

Effect of pressure support ventilation and positive end expiratory pressure on the rapid shallow breathing index in intensive care unit patients

Objective We compared rapid shallow breathing index (RSBI) values under various ventilatory support settings prior to extubation. Design and setting Prospective study in the intensive care unit at a university hospital. Patients Thirty six patients ready for extubation. Interventions Patients were enrolled when receiving pressure support ventilation (PSV) of 5 cmH₂O, PEEP of 5 cmH₂O, and FIO₂ of 40% (PS). Subsequently each patient received a trial of PSV of 0 cmH₂O, PEEP of 5 cmH₂O, and FIO₂ of 40% (CPAP), a trial of PSV of 0 cmH₂O, PEEP of 5 cmH₂O and FIO₂ of 21% (CPAP-R/A), and a 1-minute spontaneously breathing room air trial off the ventilator (T-piece). Trials were carried out in random order. Measurements and results Respiratory frequency (f) and tidal volume (V_T) were measured during PS, CPAP, CPAP-R/A, and T-piece in all patients. RSBI (f/V_T) was determined for each patient under all experimental conditions, and the average RSBI was compared duringPS, CPAP, CPAP-R/A, and T-piece. RSBI was significantly smaller during PS (46 ± 8bpm/l), CPAP (63 ± 13bpm/l) and CPAP-R/A (67 ± 14bpm/l) vs. T-piece (100 ± 23bpm/l). There was no significant difference in RSBI between CPAP and CPAP-R/A. RSBI during CPAP and CPAP-R/A were significantly smaller than RSBI during T-piece. In all patients RSBI values were less than 105 bpm/l during PS, CPAP, and CPAP-R/A. However, during T-piece the RSBI increased to greater than 105 bpm/l in 13 of 36 patients. Conclusions In the same patient the use of PSV and/or PEEP as low as 5 cmH₂O can influence the RSBI. In contrast, changes in FIO₂ may have no effect on the RSBI.     

Inspiratory vs. expiratory pressure-volume curves to set end-expiratory pressure in acute lung injury

Objective To study the effects of two levels of positive end-expiratory pressure (PEEP), 2 cmH₂O above the lower inflection point of the inspiratory limb and equal to the point of maximum curvature on the expiratory limb of the pressure-volume curve, in gas exchange, respiratory mechanics, and lung aeration.Design and setting Prospective clinical study in the intensive care unit and computed tomography ward of a university hospital.Patients Eight patients with early acute lung injury.Interventions Both limbs of the static pressure-volume curve were traced and inflection points calculated using a sigmoid model. During ventilation with a tidal volume of 6 ml/kg we sequentially applied a PEEP 2 cmH₂O above the inspiratory lower inflection point (15.5±3.1 cmH₂O) and a PEEP equal to the expiratory point of maximum curvature (23.5±4.1 cmH₂O).Measurements and results Arterial blood gases, respiratory system compliance and resistance and changes in lung aeration (measured on three computed tomography slices during end-expiratory and end-inspiratory pauses) were measured at each PEEP level. PEEP according to the expiratory point of maximum curvature was related to an improvement in oxygenation, increase in normally aerated, decrease in nonaerated lung volumes, and greater alveolar stability. There was also an increase in PaCO₂, airway pressures, and hyperaerated lung volume.Conclusions High PEEP levels according to the point of maximum curvature of the deflation limb of the pressure-volume curve have both benefits and drawbacks.This work was supported by a grant from Fondo de Investigación Sanitaria (PI03/0833) and Red GIRA (G03/063)     

机械通气患者呼气末正压对膀胱压的影响

目的：探讨机械通气患者呼气末正压（PEEP）对膀胱压的影响。方法选取我院重症医学科机械通气且监测膀胱压的患者40例,将膀胱压正常＜1．47 kPa（15 cmH2 O）的患者23例作为A组,膀胱压增高≥1．47 kPa （15 cm H2 O ）的患者17例作为 B 组,采用自身对照法,观察患者在断开呼吸机及使用呼气末正压0 kPa （0 cmH2O）、0．294 kPa （3 cmH2O）、0．490 kPa（5 cmH2O）、0．981 kPa（10 cmH2O）和1．47 kPa（15 cmH2O）时的膀胱压变化。结果A组患者在不同呼气末正压时膀胱压的变化差异无统计学意义（P＞0．05）。B组患者在呼气末正压＞0．294 kPa（3 cmH2 O）时随着呼气末正压的增高膀胱压也会随之增高,差异有统计学意义（P＜0．05）,呼气末正压为≤0．294 kPa（3 cmH2 O）时与断开呼吸机时测得的膀胱压比较,差异无统计学意义（P＞0．05）。结论膀胱压＜1．47 kPa（15 cm H2 O ）时,可保持呼吸机的呼气末正压正常调整,以保证患者的氧合,保障患者的安全。膀胱压≥1．47 kPa（15 cmH2 O）时,应保持呼吸机的呼气末正压≤0．294 kPa（3 cmH2 O）的水平,以保证患者的氧合,保障患者的安全。     

A comparative study of the cardiorespiratory effects of continuous positive airway pressure breathing and continuous positive pressure ventilation in acute respiratory failure

Positive end expiratory pressure (PEEP) produces cardiopulmonary effects whether administered by controlled positive pressure ventilation (CPPV) or continuous positive airway pressure (CPAP). In eight patients with acute respiratory failure, the effects of 20 cm PEEP administered via CPPV and CPAP were compared. An esophageal balloon was used to calculate the transmural vascular pressures. The control values under mechanical ventilation with no PEEP (IPPV) for PaO₂ and QS/QT (FiO₂ being 1.0) were respectively 132±15 mmHg and 31±3%; CPPV gave a PaO₂ of 369±27 mmHg and QS/QT fo 14±1.6%, CPAP 365±18 mmHg and 18±1.3% respectively. The two different modes of ventilation (CPPV and CPAP) gave identical blood gas improvement through the same level of end expiratory transpulmonary pressure despite marked differences between absolute mean airway and esophageal pressures. Conversely, hemodynamic tolerance was very different from one technique to the other: CPPV depressed cardiac index from 3.4±0.3 to 2.4±0.2 l/min/m² as well as decreasing transmural filling pressures, suggesting a reduction in venous return. Conversely, filling pressures maintained at control values during CPAP and cardiac indexes were unchanged.Abbreviations IPPV intermittent positive pressure ventilation; mechanical ventilation (controlled mode) with zero end expiratory pressure (ZEEP) - CPPV continuous positive pressure ventilation: mechanical ventilation (controlled mode) with a positive pressure during expiration - CPAP continuous positive airway pressure; spontaneous ventilation with a positive pressure maintained during expiration - PEEP positive end expiratory pressure, whatever the ventilatory mode; spontaneous (CPAP) or mechanical (CPPV) Presented in part at the 44 th annual meeting of American College of Chest Physicians, Washington DC, October 1978     

呼气末正压对中枢性呼吸衰竭患者血流动力学的影响

目的 评估呼气末正压(PEEP)对中枢性呼吸衰竭患者血流动力学参数如中心静脉压(CVP)、平均动脉压(MAP)和心率(HR)的影响.方法 2009年6月至2011年5月期间32例上海浦东新区浦南医院神经外科ICU中枢性呼吸衰竭患者入选此项前瞻性自身对照研究,其中男19例,女13例,年龄(58.8±13.9)岁,GCS评分≤8分.排除严重心、肺、心包疾病,及人机对抗、应用血管活性药物及血容量过高或过低等情况.所有患者予同步间隙指令通气(SIMV),在随机选择的PEEP水平(0、3、6、9、12、15 cm H2O,1 cmH2O=0.098 kPa)记录患者CVP、MAP及HR的变化,每个PEEP水平间隔10 min.采用单因素方差分析和一元线性回归模型对数据进行分析.结果 CVP随PEEP增加而增高,PEEP与CVP检测值呈正相关(R=0.468,P=0.000),一元线性回归方程为:CVP (cm H2O)=7.870+0.344×PEEP(cm H2O).在不同PEEP水平时,MAP差异无统计学意义(F=1.390,P=0.227).MAP和HR与PEEP无线性相关(R=0.042和0.160,P=0.413和0.002).结论 PEEP可使中枢性呼吸衰竭患者CVP检测值偏高,而对MAP无明显影响.该结果可对实施PEEP条件下检测的CVP值进行动态客观评估提供量化参考.     

呼气末正压对不同呼吸系统顺应性患者中心静脉压的影响

目的探讨呼气末正压（PEEP）对不同呼吸系统顺应性患者中心静脉压（CVP）的影响。 方法将2017年11月至2018年2月入住东南大学附属中大医院重症医学科需要监测CVP的55例机械通气患者依据呼吸系统静态顺应性（Crs）分为高顺应性组［Crs ≥ 0.63 ml/（cmH₂O?kg）,1 cmH₂O=0.098 kPa］和低顺应性组［Crs < 0.63 ml/（cmH₂O?kg）］,分别观察2组患者PEEP在5、10、15 cmH₂O下的CVP、心率、血压及呼吸力学的变化。 结果高顺应性组和低顺应性组患者CVP均随着PEEP增加而升高,差异具有统计学意义（P<0.05）。高顺应性组患者PEEP分别在5、10、15 cmH₂O时,CVP分别为（8.4±2.7）、（10.3±2.5）、（12.2±2.5）cmH₂O,差异具有统计学意义（P<0.05）。低顺应性组PEEP分别在5、10、15 cmH₂O时,CVP分别为（9.6±2.9）、（11.0±2.8）、（12.2±2.7）cmH₂O,差异具有统计学意义（P<0.05）。与低顺应性组患者相比,高顺应性组患者CVP随着PEEP增加而升高更为显著,差异具有统计学意义（P<0.05）。 结论对于机械通气患者,PEEP的增加会引起CVP的增加,呼吸系统顺应性高的患者CVP增加更为显著。