经鼻面罩机械通气在心脏术后患者中的应用

心脏手术患者术后常常合并心功能,呼吸功能不全需要及时救治,在常规药物治疗基础上及早提供正压通气,是改善低氧血症最有效的方法,但气管插管机械通气会给病人带来痛苦,对于一般呼吸功能不全患者可使用无创正压通气。现将我院自2009年1月至4月以来对23例心脏术后患者进行BiPAP呼吸机辅助治疗的临床效果作一分析。     

影响机械通气撤离的因素与临床实施流程

机械通气时间的延长与院内获得性肺炎的发生、呼吸机依赖以及病死率密切相关[1].因此,及早撤离呼吸机、拔出气管插管是减轻患者痛苦,减少并发症的重要途径.Tindol等[2]的研究结果显示,约50％意外拔出气管插管的患者自主呼吸状况良好,不需要再次建立人工气道.这一结果提示,临床医生过低估计了部分患者的自主呼吸功能,延迟了脱离人工气道的时间.然而过早的拔出气管插管同样无益,上述临床观察的另一结果是,意外拔出气管插管又需要呼吸支持的患者在ICU的住院时间延长,在院病死率增加.本文从影响因素和实施流程出发,简述目前机械通气撤离的方法.     

经鼻间歇正压通气与经鼻持续气道正压通气治疗早产儿呼吸窘迫综合征的疗效比较

目的比较经鼻间歇正压通气(NIPPV)与经鼻持续气道正压通气(NCPAP)治疗早产儿呼吸窘迫综合征(RDS)的临床效果。方法选取2016年7月至2019年6月在我院新生儿监护室治疗的轻中度RDS(Ⅰ～Ⅲ级)早产儿96例为研究对象,随机分为NIPPV组(52例)和NCPAP组(44例),分别给予NIPPV或NCPAP呼吸支持治疗,同时使用注射用牛肺表面活性剂(PS,珂立苏,70 mg/kg)进行替代治疗。比较两组患儿的基本情况、动脉血气分析结果、治疗成功率、NIPPV或NCPAP的使用时间以及主要并发症发生情况。结果两组患儿产前母亲使用激素情况、出生胎龄、性别、出生体重、1 min Apgar评分、5 min Apgar评分、RDS分级、出生后使用PS时间比较差异无统计学意义(P0.05)。治疗2 h、6 h、12 h后,两组患儿的血pH、PaO_2、PaCO_2均有所改善,NIPPV组患儿的改善情况优于NCPAP组,差异有统计学意义(P0.05)。NIPPV组患儿的治疗成功率(92.3%)显著高于NCPAP组(81.8%),使用呼吸机时间显著短于NCPAP组,差异有统计学意义(P0.05)。NIPPV组患儿呼吸暂停、重新插管机械通气的发生率均显著低于NCPAP组,差异有统计学意义(P0.05)。结论使用NIPPV呼吸支持治疗RDS早产儿,能更有效地改善动脉血气分析结果,提高治疗成功率,缩短呼吸机使用时间,降低并发症发生率,治疗效果优于使用NCPAP治疗。     

婴儿体外循环心脏直视手术后肺部并发症的处置体会

目的总结婴儿体外循环心脏直视手术后肺部并发症的处置经验。方法选择该院120例婴儿心脏术后出现肺部并发症的患儿,其中单纯肺不张患儿60例,予加强拍背、吸痰等处理;单纯气胸15例,予胸穿抽气治疗;急性肺损伤并肺部感染45例,给予恰当的机械通气、抗感染等综合治疗。结果 120例患儿死亡3例,余117例治愈出院。结论加强肺部体位治疗,合理使用呼吸机、小潮气量的肺保护性通气策略,适当的呼吸末正压设置,积极抗感染、营养支持等有助于提高心脏术后肺部并发症的治愈率。     

体外循环心脏术后呼吸系统的监护

目的总结体外循环心脏术后患者的呼吸系统监护经验。方法对392例体外循环心脏手术后患者分别在合理的机械通气治疗、加强病情观察、保持气管插管的固定和呼吸道通畅、注重气道的湿化以及加强对机械通气常见的不良后果监护、预防呼吸道并发症等方面进行回顾分析。结果 392例患者中除23例插管移位(需更换插管)、19例出现肺不张等并发症、5例患者因心肾呼吸功能衰竭放弃治疗自动出院外,其余均无呼吸道并发症。结论体外循环心脏手术后给予患者合理的机械通气,加强呼吸道的管理,注重机械通气常见不良后果的监护可以降低术后呼吸并发症的发生率,提高手术成功率,促进患者尽早康复。     

肺表面活性物质联合鼻塞式持续气道正压通气治疗新生儿肺透明膜病的临床效果分析

目的分析肺表面活性物质(PS)联合鼻塞式持续气道正压通气(NCPAP)治疗新生儿肺透明膜病的临床效果。方法选取2014年6月—2016年3月咸阳市中心医院新生儿科收治的新生儿肺透明膜病患儿80例,按照入院顺序分为对照组和试验组,每组40例。对照组患儿给予NCPAP治疗,试验组患儿给予PS联合NCPAP治疗。比较两组患儿治疗前后血气分析指标〔动脉血氧分压(PaO_2)、PaO_2/吸入氧浓度(FiO_2)及动脉血二氧化碳分压(PaCO_2)〕,治疗及住院情况(包括高压力持续时间、高FiO_2持续时间、NCPAP治疗时间及住院时间),转归情况(包括治愈、再次插管机械通气、死亡、放弃治疗)及并发症情况(气胸、肺炎等)。结果时间与方法在PaO_2、PaO_2/FiO_2及PaCO_2上存在交互作用(P0.05);时间在PaO_2、PaO_2/FiO_2及PaCO_2上主效应显著(P0.05);方法在PaO_2、PaO_2/FiO_2及PaCO_2上主效应显著(P0.05);治疗后1、12、24 h,试验组患儿PaO_2、PaO_2/FiO_2均高于对照组,PaCO_2均低于对照组(P0.05);且两组患儿治疗后1、12、24 h PaO_2、PaO_2/FiO_2均高于治疗前,PaCO_2均低于治疗前(P0.05)。试验组患儿高压力持续时间、高FiO_2持续时间、NCPAP治疗时间及住院时间均短于对照组(P0.05)。试验组患儿治愈率高于对照组,再次插管机械通气者所占比例低于对照组(P0.05);两组患儿病死率和放弃治疗率比较,差异无统计学意义(P0.05)。试验组患儿并发症发生率低于对照组(P0.05)。结论 PS联合NCPAP可有效改善新生儿肺透明膜病患儿血气分析指标,缩短NCPAP治疗时间及住院时间,降低再次插管机械通气率和并发症发生率。     

经鼻持续正压通气治疗新生儿急性呼吸衰竭临床研究

目的观察经鼻持续正压通气（NCPAP）治疗新生儿急性呼吸衰竭的疗效。方法对收治的22例急性呼吸衰竭新生儿使用NCPAP治疗后疗效及转归进行分析。结果治疗有效19例,无效3例。应用NCPAP后PO2、PaCO2、pH、R、HR均有明显改善（P〈0.05）。结论 NCPAP治疗新生儿呼吸衰竭有良好的治疗效果,可减少气管插管,减少机械通气,是一种简便、适宜的新生儿呼吸支持技术。     

有创-无创序贯通气与非序贯无创通气在婴幼儿先天性心脏病外科术后的应用

目的 评估婴幼儿复杂先天性心脏病术后患儿拔管后序贯无创的疗效和无创通气对婴幼儿复杂先天性心脏病术后出现急性呼吸衰竭的疗效.方法 回顾性研究2008年1月至2013年12月间入住我院ICU的951例复杂先天性心脏病术后婴幼儿（年龄≤1岁,体重≤10 kg）,665例患儿顺利脱机拔管,未行无创通气和二次气管插管治疗,286例患儿使用无创通气（NIV）治疗.将286例使用无创通气治疗的患几分为2组,一组为拔除气管插管后给予直接无创通气治疗称为序贯无创组（155例）,另一组为拔管后出现急性呼吸衰竭表现后给予无创通气治疗称为非序贯无创组（131例）.观察非序贯组无创通气治疗前,治疗后1h、2h、3h心率（HR）、呼吸频率（RR）、血压（BP）、血氧饱和度（SpO2）和血气分析（PH、PO2、PCO2）值的变化,比较序贯无创通气组和非序贯无创通气组的并发症、无创通气使用时间、再次使用气管插管的比率、ICU停留时间、住院天数和死亡率.结果 序贯无创组中有12例患儿出现严重呼吸衰竭不能改善,行气管插管机械辅助,其中3例患儿因严重的心功能衰竭死亡,另9例患儿痊愈出院.非序贯组中有20例患儿出现严重呼吸衰竭不能改善,行气管插管机械辅助,其中4例患儿出现严重心功能衰竭死亡,2例患儿出现MODS死亡,余14例痊愈出院.序贯无创组的无创通气相关并发症、无创通气使用时间和死亡率与非序贯组相当,但序贯组的二次插管率、住院时间、ICU停留时间较非序贯组明显缩短,差异具有统计学意义.结论 无创通气可以治疗婴幼儿复杂先天性心脏病术后急性呼吸衰竭,是一种安全有效的方法.序贯无创通气在低龄、低体重婴幼儿复杂先天性心脏病术后能降低二次插管率,缩短ICU停留时间和住院天数,减少费用.     

33例肺动脉吊带患儿术后治疗

目的总结肺动脉吊带(PAS)患儿术后治疗策略及临床治疗经验。方法纳入我科2006年11月至2013年12月期间收治的33例PAS患儿,单纯PAS及合并动脉导管未闭患儿20例,合并有心内畸形患儿13例。回顾性分析患儿术后主要治疗方法包括呼吸机及无创持续气道正压通气(NCPAP)辅助呼吸、血管活性药物支持心功能,收集相关临床资料进行分析。结果患儿呼吸机辅助时间2⁸65 h;其中4例(12.1%)需要再次气管插管;7例(21.2%)拔除气管插管后需要NCPAP辅助,应用时间为1865 h;其中4例(12.1%)需要再次气管插管;7例(21.2%)拔除气管插管后需要NCPAP辅助,应用时间为1¹5 d。20例单纯PAS患儿中有4例(20.0%)进行了小剂量、短时间的血管活性药物的支持,而13例合并有心内畸形、需要心内手术操作的患儿中有9例(69.2%)在监护室内进行了血管活性药物的支持(P<0.01)。患儿ICU滞留时间为115 d。20例单纯PAS患儿中有4例(20.0%)进行了小剂量、短时间的血管活性药物的支持,而13例合并有心内畸形、需要心内手术操作的患儿中有9例(69.2%)在监护室内进行了血管活性药物的支持(P<0.01)。患儿ICU滞留时间为1³9 d;其中2例(6.1%)重返ICU。33例患儿手术均成功,除1例因气道狭窄明显、脱机困难,家长放弃治疗外,其他32例患儿均康复出院。结论术后尽早脱离气管插管、必要的NCPAP支持及血管活性药物的适当应用,是保证PAS患儿术后康复的主要治疗措施。     

有创机械通气呼吸机依赖患者的治疗对策探讨

目的探讨有创机械通气患者发生呼吸机依赖的临床特点、原因和治疗对策。方法对已成功撤机的14例呼吸机依赖患者进行回顾性分析。结果本组14例全部撤机存活,无1例在1周内因呼吸因素再次插管上机或死亡。影响撤机困难主要原因有营养不良、心、肺功能不全和心理依赖等因素。结论有创机械通气能否成功撤机,依赖于临床医师撤机时机的掌握,与患者基础疾病、营养状态、呼吸功能和其他脏器的功能密切关联。加强病因治疗及有利撤机等综合有效措施,可提高呼吸衰竭治疗的成功率,安全撤机是可行的。     

机械通气治疗COPD撤机失败原因的回顾性研究

目的研究机械通气治疗COPD患者撤机失败的原因。方法收集我院2004年1月至2008年12月住院的38例共45次COPD患者撤机失败、进行回顾性研究,总结撤机失败的原因。结果38例45次撤机失败的原因：感染未控制18例次（40．0％）;呼吸肌疲劳10例次（22．2％）;呼吸机依赖7例次（15．6％）;并发症致再次接机6例次（13．3％）;误吸致再次接机3例次（6．7％）,其他1例次（2．2％）。结论有效的抗感染治疗,加强营养支持,防治并发症和注意心理疏导是防止撤机失败的主要措施。     

Dynamic behavior of respiratory system during nasal continuous positive airway pressure in spontaneously breathing premature newborn infants

The end-expiratory lung-volume level of premature newborn infants is maintained above passive resting volume during active breathing, through the combination of reduced time constant and high respiratory rate. To determine whether nasal continuous positive airway pressure (NCPAP) alters this characteristic dynamic breathing pattern, we studied the effects of various NCPAP levels on the dynamic elevation of end-expiratory lung volume level (DeltaEELV) in spontaneously breathing premature newborn infants, using respiratory inductive plethysmography (RIP). Eleven premature newborn infants with moderate respiratory failure were included. NCPAP levels were set in a random order to 0, 2, 4, and 6 cm H2O. Tidal volume (Vt), rib-cage contribution to Vt (%RC), phase angle between abdominal and thoracic motions (theta), respiratory rate (RR), and inspiratory and expiratory times (Ti and Te) were continuously recorded by RIP. The slope of the linear part of the expiratory flow-volume relation was extrapolated up to zero flow level to evaluate the dynamic elevation of the functional residual capacity (FRC) (DeltaEELV). The time-constant of the respiratory system (tauRS) was calculated as the slope of the linear part of the expiratory flow-volume loop. At NCPAP = 6 cm H2O, DeltaEELV reached 0.6 +/- 0.2 times the Vt at NCPAP = 0 cm H2O. An increase in NCPAP level resulted in a significant decrease in DeltaEELV (P < 0.01). A decrease in DeltaEELV during NCPAP was associated with a significant increase in Te from 0.62 +/- 0.13 sec at NCPAP = 0 cm H2O to 0.80 +/- 0.07 sec at NCPAP = 6 cm H2O (P < 0.05), and a decrease in tauRS from 0.4 +/- 0.1 sec at NCPAP = 0 cm H2O to 0.24 +/- 0.04 sec at NCPAP = 6 cm H2O (P < 0.01). These results indicate that the characteristic spontaneous breathing pattern causing a dynamic elevation of FRC is abolished by NCPAP. We speculate that the dynamic volume-preserving mechanisms resulting from expiratory flow braking are no longer required during NCPAP, as the constant pressure may passively elevate FRC.     

Effects on respiration of CPAP immediately after extubation in the very preterm infant

The effects of continuous positive airway pressure (CPAP) on pulmonary function during weaning from ventilator treatment were examined immediately after extubation in 17 very preterm infants, who had been ventilator-treated because of hyaline membrane disease (15 infants) and chronic pulmonary insufficiency of prematurity (two infants). Seven infants had bronchopulmonary dysplasia. Median birthweight was 920 g and median gestational age 26 completed weeks. The median duration of ventilator treatment was 10 days. Application of CPAP by means of a face chamber device after endotracheal extubation significantly lowered the frequency of apnea (P = 0.02) and enhanced oxygenation (P = 0.001). The respiratory mechanical indices derived from flow rate and juxta-diaphragmatic esophageal pressure measurements showed a reduced elastic (P = 0.03) and resistive (P = 0.02) load on the diaphragm. Even if the measured values do not accurately represent absolute resistances and compliances, the relative values of end-inspiratory and end-expiratory pressures differed significantly with and without CPAP (P = 0.001 and 0.002, respectively). We found CPAP applied via the face chamber technique immediately after extubation to be beneficial and to facilitate weaning from ventilator treatment in very preterm infants.     

新生儿机械通气撤机失败的影响因素及预测指标分析

目的探讨导致新生儿机械通气撤机失败的影响因素及寻找预测指标减少撤机失败率。方法回顾性分析我院2015年1月至2019年12月新生儿重症监护病室350例机械通气时间≥72 h并存活的新生儿。根据撤机48 h内是否再次插管,分为撤机成功组与撤机失败组。比较两组撤机前一般情况、临床变量、呼吸机设置及血气分析,撤机后无创通气模式及雾化情况。单因素及多因素分析确定高危因素,并预测指标价值。结果47例(13.4%)发生撤机失败。单因素分析显示15个变量是撤机失败的影响因素(P<0.05)。Logistic回归分析示机械通气时间长、吸痰耐受能力差、多脏器损害、高PCO 2、撤机时自主呼吸及心率快是撤机失败的高危因素(P<0.05)。PCO₂预测撤机失败价值高,AUC为0.819(0.738,0.900),P<0.001。结论多种因素与撤机失败相关,应针对高危因素进行干预,撤机前进行充分预测评估以减少撤机失败率。     

Is airway occlusion pressure useful to predict successful weaning from mechanical ventilation in patients with acute respiratory failure?

The purpose of this study was to evaluate whether airway occlusion pressure (P0.1) would be a useful predictor for successful weaning in mechanically ventilated patients with acute respiratory failure. We studied 23 marginal weaning candidates. Fourteen patients were able to be weaned from the ventilator, and 9 patients were not able to be weaned. P0.1 and other respiratory parameters were measured just prior to weaning and at the end of weaning or at the time of discontinuation of weaning. The mean value of P0.1 in the failed group was higher than that in the successful group both before and after weaning periods. However, P0.1 varied widely among patients and did not separate the failure group from the success group because of overlap between the two. There were significant differences between the two groups of the conventional weaning parameters, such as respiratory rate, minute ventilation, PaO2, and oxygen equivalent. We conclude that P0.1 is helpful to predict successful weaning. However, it can not be used as a single parameter for weaning because of the wide variations of absolute values among patients with acute respiratory failure.     

Changes in lung volume and work of breathing: A comparison of two variable-flow nasal continuous positive airway pressure devices in very low birth weight infants

Variable flow nasal continuous positive airway pressure (VF-NCPAP) recruits lung volume more effectively and reduces work of breathing (WOB) compared to constant-flow NCPAP (CF-NCPAP) in very low birth weight (VLBW) infants. Because different VF-NCPAP devices have somewhat different flow patterns, whether different VF-NCPAP devices function similarly is unknown. We compared two VF-NCPAP devices: the Infant Flow trade mark (EME, Ltd.) and the Arabella(R) (Hamilton Medical) to assess whether lung volume recruitment and WOB were similar in VLBW infants requiring NCPAP. Eighteen infants <1,500 g were studied on both NCPAP devices applied in random order. All infants required NCPAP for mild respiratory distress. Calibrated DC-coupled respiratory inductance plethysmography (RIP) was used to assess lung volume changes. NCPAP was first increased to 8 cmH(2)O to allow comparable recruitment in all infants, and then was slowly decreased to 6, 4, and 0 cmH(2)O, with data collection at each level. Mean birth weight (+/-SD) was 1,107 +/- 218 g, gestational age was 27.9 +/- 2.0 weeks, weight at study was 1,092 +/- 222 g, and age at study was 4.6 +/- 4.3 days. There were no differences in lung volume recruitment overall or at any NCPAP level (P = 0.943). No differences were found in either inspiratory WOB (P = 0.468) or in resistive WOB (P = 0.610) between devices. Compliance, tidal volume, respiratory rate, and minute ventilation were also similar. Despite differences in flow characteristics between the two VF-NCPAP devices we studied, lung volume recruitment and WOB were similar.     

Synchronized nasal intermittent positive pressure ventilation (SNIPPV) decreases work of breathing (WOB) in premature infants with respiratory distress syndrome (RDS) compared to nasal continuous positive airway pressure (NCPAP)

Synchronized nasal intermittent positive pressure ventilation (SNIPPV) is non-invasive respiratory support that delivers ventilator breaths via the nasal prongs. We hypothesized that SNIPPV is more effective than nasal continuous positive airway pressure (NCPAP) in premature neonates due to decreased work of breathing (WOB). Fifteen infants (BW: 1,367 +/- 325 g, GA: 29.5 +/- 2.4 weeks) were studied on (a) NCPAP at 5 cmH(2)O (NCPAP5) and (b) three increasing SNIPPV settings achieved by NCPAP5 with additional delivered peak inspiratory pressures (PIP) of 10, 12, and 14 cmH(2)O. Tidal volumes and transpulmonary pressures were estimated via calibrated respiratory inductance plethysmography (RIP) and esophageal pressures, respectively. Inspiratory (WOB(insp)), resistive (RWOB), and elastic (WOB(E)) components of WOB were calculated using standard methods. Compared to NCPAP5, (a) WOB(insp) and RWOB were significantly lower with SNIPPV12, and were similarly lower with SNIPPV14 and (b) WOB(E) was significantly lower only with SNIPPV14. WOB components did not differ significantly for the three SNIPPV settings. Tidal volume, respiratory rate (RR), minute ventilation, compliance, and phase angle were similar for all four measurements. In conclusion, compared to NCPAP, the addition of ventilator-delivered PIP during SNIPPV decreases WOB in premature infants.     

Factors associated with failure of weaning from long-term mechanical ventilation after cardiac surgery

The purpose of this prospective, quantitative, comparative study, conducted at the 55 bed cardiothoracic intensive care unit of the Heart Institute (InCor), University of Sao Paulo Medical School, was to identify factors involved in the weaning of patients who require long-term (> 10 days) mechanical ventilation after cardiac surgery. The subjects included all patients who underwent open-heart surgery with cardiopulmonary bypass during a 10 month period from April 2000 to January 2001 (n = 946). From this group, 52 (5.7%) patients who required a tracheotomy for the management of long-term mechanical ventilation after cardiac surgery with cardiopulmonary bypass were selected. Pre-, intra- and postoperative data from patients who were not successfully weaned after reintubation and who underwent an elective tracheotomy were compared. Parameters of respiratory mechanics such as respiratory complications, oxygenation, and cardiac, renal, and neurological function were evaluated. Weaning success was defined as the ability of a patient to tolerate 48 hours without pressure or flow support from a mechanical ventilator. A patient was considered to have failed weaning if they died or remained under ventilation for more than 8 weeks. Of the 52 patients studied, 25 were successfully weaned, 21 died, and 6 remained ventilated for more than 8 weeks. We found significant statistical differences (P < 0.05) between the groups with respect to success or failure in LVEF (P = 0.0035), the need for vasoactive agents (P = 0.0018), and renal failure (P = 0.002). Parameters of respiratory mechanics and oxygenation (eg, static airway compliance, airway resistance) did not influence the success or failure of weaning. There was a significant difference in relation to the presence of pneumonia (P = 0.0086) between the two groups. Although neurological complications were more frequent in patients in the weaning success group, the failure group had lower GCS scores, which is indicative of worse prognoses. It is concluded that cardiac dysfunction, the need for dialysis, and pneumonia are determinants for weaning failure in patients undergoing long-term mechanical ventilation after cardiac surgery.