轻度肺通气功能障碍对单肺通气期间氧合和肺内分流的影响

目的:观察术前轻度肺通气功能障碍对单肺通气期间血液氧合及肺内分流的影响.方法:40例ASA Ⅰ～Ⅱ级择期需行单肺通气开胸手术的成年患者,根据术前肺功能测定结果,将患者分为肺通气功能正常组(Ⅰ组)及轻度肺通气功能障碍组(Ⅱ组),每组20例.分别于患者右侧卧双肺通气10min(T0),单肺通气10min(T1)、20min(T2)、30min(T3)、40 min(T4)抽取动、静脉血行血气分析并计算肺内分流率(Qs/Qt).结果:Ⅰ组患者单肺通气各时点动脉血氧分压(PaO2)较双肺通气时明显下降(P<0.05),Qs/Qt明显增加(P<0.05).Ⅱ组患者单肺通气各时点PaO2较双肺通气时明显升高(P<0.05),Qs/Qt则无明显改变,两组患者动脉血二氧化碳分压(PaCO2)、pH值、平均动脉压(MAP)、心率(HR)、脉搏血氧饱和度(SpO2)、呼气末二氧化碳分压(PETCO2)等在单肺通气期间无明显改变(P>0.05);与Ⅰ组比较,Ⅱ组患者各时点PaO2、Qs/Qt均有明显差异(P<0.05),而PaCO2、pH、MAP、HR、SpO2、PETCO2等则无明显差异(P>0.05).结论:术前轻度肺通气功能障碍患者较肺通气功能正常者单肺通气期间具有更好的血液氧合趋势,肺内分流则无明显增加,单肺通气期间低氧血症发生的危险性降低.     

帕瑞昔布钠对单肺通气患者肺内分流和炎性细胞因子的影响

【目的】探讨帕瑞昔布钠对单肺通气（one-lung ventilation,OLV）患者肺内分流和炎性细胞因子的影响。【方法】择期行0LV麻醉的患者30例,随机均分为两组：帕瑞昔布钠组（P组）和对照组（C组）。于麻醉诱导后双肺通气（two-lung ventilation,TLV）30min（T0）、OLV30min（T1）、OLV60min（T2）、恢复TLV30min（T3）四个时点测定心率（HR）、平均动脉压（MAP）和气道平均压（Paw）,同时采集颈内静脉和桡动脉血样,进行血气分析,计算肺内分流率（Qs／Qt）;测定血清肿瘤坏死因子-α（TNF-α）及白细胞介素-6（IL-6）、IL_10浓度。【结果】与T0时比较,两组T1～T2时Paw和Qs／Qt升高（P〈0．05）;与T1时比较,两组T3时Qs／Qt降低（P〈0．05）;两组各时点Paw、Qs／Qt、HR和MAP比较差异无统计学意义（P〉0．05）。两组TNF-α、IL-6血浆浓度T1～T3时点明显高于T0（P〈0．05）,IL-10浓度T2,T3时点明显高于T0（P〈0．05）;与C组相比,P组T2,T3时点TNF-α、IL-6浓度均较低（P〈0．05）,IL-10浓度较高（P〈0．05）。【结论】帕瑞昔布钠不增加0LV期间的肺内分流,可减轻0LV患者围手术期的炎性反应。     

舒芬太尼或芬太尼联合利多卡因对全麻气管插管时血流动力学的影响

目的 观察舒芬太尼、芬太尼与利多卡因联合用于全麻诱导插管期对血流动力学的影响。方法 择期全麻手术病例60例，按诱导药物不同随机平均分为三组：利多卡因组（Ⅰ组）、芬太尼合用利多卡因组（Ⅱ组）、舒芬太尼合用利多卡因组（Ⅲ组）。分别记录诱导前（T0）、插管前（T1）、插管后即刻 (T2)、插管后1 min（T3）、3 min(T4) 、5min(T5)各时点的SBP、DBP、HR。结果 诱导后T1时点三组SBP、DBP、HR显著低于T0（P<0.05或P<0.01）；插管后Ⅲ组SBP、DBP、HR与T0比较无显著差异（P>0.05）,与Ⅰ组相比在T2、T3、T4、T5时SBP、DBP及HR在T2、T3时均显著低于Ⅰ组（P<0.01或P<0.05），在T2、T3时SBP、DBP、HR明显低于Ⅱ组（P<0.05）；Ⅱ组在T2、T3与T0比较SBP、DBP明显升高（P<0.05），HR在T4、T5时与T0比明显下降（P<0.05），与Ⅰ组比较SBP、DBP、HR低于Ⅰ组（P<0.05）；Ⅰ组SBP、DBP、HR明显高于T0时点（P<0.05或P<0.01）。结论 舒芬太尼、芬太尼与利多卡因联合能较好地抑制气管插管时的应激反应，舒芬太尼在维持血流动力学方面更有优势。     

瑞芬太尼与芬太尼对腹部手术患者麻醉气管插管血流动力学的影响

目的观察瑞芬太尼与芬太尼对腹部手术患者麻醉气管插管血流动力学的影响。方法择期行腹部手术病人42例，ASAⅠ～Ⅱ级、年龄18～72岁，随机分为瑞芬太尼组（R组，21例）、芬太尼组（F组，21例）；诱导方法：丙泊酚2mg／kg、罗库溴胺0．6mg／kg，其中R组用瑞芬太尼2μg／kg，F组采用芬太尼3μg／kg快速诱导；记录以下各时点的SBP、DBP、HR，麻醉诱导前1min（T0），诱导后1min插管前即刻（T1）及插管后1min（T2）、3min（T3），5min（T4）。结果R组SBP、DBP、HR在T1、T2、T3与基础值及与F组比较降低，差异分别为P〈0．01、P〈0．05，插管后5min回升至插管前水平。F组SBP、DBP在T1降低，T3恢复至插管前水平，HR差异无统计学意义。结论芬太尼、瑞芬太尼均能维持患者麻醉诱导插管时血流动力学稳定，瑞芬太尼抑制气管插管的应激反应优于芬太尼，但心率减慢、血压下降亦比芬太尼明显。     

高频喷射通气辅助单肺通气在Ⅰ型呼吸衰竭患者胸科手术中的应用

【目的】探讨单肺通气（OLV）中非通气侧肺高频喷射通气（HFJV）在I型呼吸衰竭患者中的作用。【方法】选择合并I型呼吸衰竭全麻单肺通气胸科手术患者34例,随机分为两组,每组17例,全麻快速诱导后插入双腔支气管导管,HFJV组（H组）单肺通气后非通气侧肺行HFJV;对照组（C组）行单肺通气。分别于麻醉前（T0）及0LV前（T1）、OLV后10min（T2）、30min（T3）、60min（T4）、术毕恢复双肺通气后10min（T5）行血气分析,计算肺内分流率[肺内分流量／心输出量（Qs／Qt）],同时监测气道压力并计算肺顺应性（Cdyn）。【结果】C组有4例患者由于严重低氧血症退出该研究;与T,时比较,Tz～Ta时两组PaO2均下降,Qs／Qt、气道峰压（Pmax）升高、Cdvn下降（P〈0．05）;与C组比较,H组Tz～Tt时Paoz显著增高、Qs／Qt显著降低,其差异均有统计学意义（P〈0．05）,Pmax、Cm无显著性差异（P〉0．05）。【结论】高频喷射通气辅助单肺通气可降低I型呼吸衰竭患者肺内分流,维持较好的PaO2。     

最佳氧合法导向的PEEP对ARDS绵羊血流动力学和气体交换的影响

目的 探讨最佳氧合法导向的呼气末正压（PEEP）对急性呼吸窘迫综合征（ARDS）绵羊血流动力学和气体交换的影响。方法 肺泡灌洗法复制绵羊ARDS模型（n=6）,在充分肺复张的基础上,利用最佳氧合法滴定最佳PEEP。并维持通气2h。观察基础状态（PEEP 5 cmH2O）、ARDS模型稳定（PEEP 5cmH2O）和最佳PEEP维持通气2h的血流动力学、气体交换和呼吸力学变化。结果 最佳氧合法滴定的最佳PEEP为（18&#177;2）cmH2O。与ARDS模型比较,最佳PEEP维持通气期间心率（HR）、平均动脉压（MAP）、心脏指数（CI）、每搏指数（SVI）、中心静脉压（CVP）、平均肺动脉压（MPAP）、肺动脉嵌顿压（PAWP）和肺循环阻力指数（PVRI）差异无统计学意义（P〉0．05）,CVP、MPAP、PAWP和PVRI较基础状态明显升高（P〈0．05）。与ARDS模型稳定时比较,最佳PEEP维持通气期间动脉血二氧化碳分压（PaCO2）明显降低（P〈0．05）,氧合指数（PaO2／FiO2）和氧输送（DO2I）显著升高（P〈0．05）,肺内分流率（Qs／Qt）明显改善（P〈0．05）,且PaCO2、PaO2／FiO2、DO2I和Qs／Qt均接近基础状态（P〉0．05）。与ARDS模型稳定时比较,最佳PEEP维持通气期间的平均气道压（Pm）明显升高（P〈0．05）、平台压力（Pplat）无明显变化（P〉0．05）、肺动态顺应性（Cdyn）明显增加（P〈0．05）。结论 最佳氧合法导向的PEEP能有效地减少ARDS绵羊的肺内分流、改善氧合和肺顺应性,对血流动力学无明显影响。     

婴儿腹腔镜下幽门环肌切开术麻醉管理

目的:探讨婴儿腹腔镜下幽门环肌切开术中的麻醉管理。方法:对45例先天性肥厚性幽门狭窄的婴儿行腹腔镜下幽门环肌切开术气管插管静吸复合麻醉,用芬太尼、咪唑安定、万可松诱导气管插管,术中用异氟醚维持麻醉。监测气腹前5min、气腹后5min及腹腔放气后5min的SPO2、心率(HR)、收缩压(SBP)、舒张压(DBP)、呼气末二氧化碳分压(PETCO2)、血气并将3组数据进行比较分析。结果:45例患儿均手术成功。麻醉期间无低氧血症发生。麻醉期间呼吸、循环相对平稳。与气腹前5min相比,气腹后5min的HR、SBP、DBP、PETCO2、PaCO2有明显上升,pH值下降(P<0.05)。结论:术中良好的呼吸管理、保持血流动力学的稳定、合理的气腹压,可使腹腔镜下行幽门环肌切开术的婴儿安全渡过手术期。     

喉罩通气并异丙酚复合瑞芬太尼麻醉在高血压患者腹腔镜胆囊切除术中的临床应用

目的探讨喉罩通气下异丙酚复合瑞芬太尼全凭静脉麻醉在高血压患者腹腔镜胆囊切除术中的临床应用价值。方法60例ASAⅡ级择期行腹腔镜胆囊切除术的高血压患者全部采用异丙酚、瑞芬太尼、维库溴铵全凭静脉麻醉（TIVA）。记录麻醉前（T0）、诱导后（T1）、插管时（T2）、气腹前（T3）、气腹后10min（T4）、术毕时（T5）及拔管时（T6）患者的SBP、DBP、HR、SPO2，连续监测喉罩插管后的气道峰压（Ppeak）与呼气末CO2分压（PETCO2），并记录麻醉恢复和麻醉并发症发生情况。结果60例患者诱导后有明显的血压下降与心率减慢，较麻醉前有显著改变（P〈O．05），麻醉维持过程中DBP、SBP、HR、SPO2无显著变化，术后苏醒快，恶心、呕吐发生率低。结论喉罩通气并异丙酚复合瑞芬太尼全凭静脉麻醉对腹腔镜胆囊切除术的高血压患者血流动力学影响小，麻醉恢复快、质量高，且并发症少，可安全用于临床。     

开胸手术单肺通气期间非通气侧肺实施持续气道正压对肺内分流和氧合的影响

目的 观察单肺通气期闻非通气侧肺实施持续气道正压（CPAP）对肺内分流和氧合的影响。 方法 40例择期开胸单肺通气行肺叶切除患者,随机分对照组（A组）和CPAP组（B组）,每组20例。单肺通气时A组病人非通气侧支气管导管与大气相通,B组病人非通气侧肺给予5cmH2O的CPAP处理。分别于单肺通气前,单肺通气30min,单肺通气结束,恢复双肺通气30min抽动脉血测血气分析,根据公式计算肺内分流率。 结果 A组病人在单肺通气30min及单肺通气结束时PaO2明显降低,而与单肺通气前比较Qs／Qt则明显增高（P〈0.05）。B组病人PaO2及Qs／Qt虽有改变但各时点之间比较差异无显著性（P〉0．05）。单肺通气30min及单肺通气结束时,PaO2B组较A组高,而Qs／Qt低于A组（P〈0．05）。 结论 单肺通气期间非通气侧肺实施5cmH2O CPAP可明显提高氧分压,减少肺内分流。     

不同麻醉方式用于乳癌根治术的对比观察

目的观察硬膜外阻滞复合全麻和单纯全麻在乳腺癌根治手术中的麻醉效果。方法选择ASAⅠ～Ⅱ级21～67岁乳腺癌根治患者40例,分成硬膜外阻滞复合全麻组（A组,n=20）,和单纯全麻组（B组,n=20）监测并记录收缩压（SBP）、舒张压（DBP）、心率（HR）、呼气末二氧化碳分压（PETCO2）、脉搏血氧饱和度（SpO2）变化,麻醉药剂量及术后麻醉恢复情况。结果 A组麻醉诱导、气管插管、切皮时、拔气管导管时SBP、DBP、HR低于B组,血流动力学稳定,呼吸恢复时间、拔管时间及苏醒时间明显短于B组。结论硬膜外阻滞复合全麻可安全有效地应用于乳腺癌根治术,提高麻醉质量。     

单向活瓣通气给氧在机械通气患者撤机中的应用研究

目的探讨在机械通气患者撤机过程中,使用单向活瓣通气给氧的方法对脱机训练的影响。方法选择行机械通气72 h以上患者48例,符合撤机标准,在准备撤机前将患者随机分成观察组和对照组各24例,观察组使用单向活瓣通气给氧的方法对患者进行脱机训练,对照组采用常规氧气管给氧通气的方法,通过观察两组患者的血气分析、呼吸频率、心率、血压变化,并了解患者的耐受性及舒适度改变等指标。结果两组患者在脱机后1 h3、h2、4 h动脉血气分析的血氧分压(PaO2)、动脉血氧饱和度(SaO2)、呼吸次数、心率、血压变化相比较,差异有显著性意义(P<0.05)。观察组患者的耐受性及舒适度明显比对照组好。结论使用单向活瓣通气给氧用于机械通气患者撤机的方法,可以使患者能吸入较精确的足够的氧混合气体,降低导管死腔,减少患者的呼吸做功,增加患者的舒适度,从而能使患者达到快速、顺利脱机的目的。     

胸科手术单肺通气期间定容模式和定压模式的比较

目的比较胸科手术单肺通气（OLV）期间采用定容（VCV）和定压（PCV）两种不同通气模式的效果。方法ASAⅠ～Ⅱ级、年龄18～68岁需行单肺通气胸科手术患者24例，随机分为Ⅰ、Ⅱ两组，每组各12例。全身麻醉诱导插双腔管后，侧卧位行双肺定容通气（TLV-VCV）后Ⅰ组先单肺定容通气（OLV—VCV）30min后行单肺定压通气（OLV—PCV），Ⅱ组单肺通气的顺序与Ⅰ组相反，即先定压通气（OLV—PCV）30min再定容通气（OLV—VCV）。双肺定容通气后，每种单肺通气后30min测定并记录心率（HR）、平均动脉压（MAP）、中心静脉压（CVP）、脉搏氧饱和度（SpO2）、气道峰压（Ppeak）、平均气道压（Pmean）、潮气量（VT）、呼吸末二氧化碳分压（PETCO2）。同时抽动血测血氧分压、氧饱和度（PaO2、SaO2）及二氧化碳分压（PaCO2）。结果患者TLV-VCV，OLV-VCV与OLV-PCV期间的HR、MAP、CVP、SpO2差异无统计学意义（P〉0．05）；OLV-VCV和OLV-PCV的Ppeak和Pmean较TLV-VCV高（P〈0．05或P〈0．01），而OLV—VCV又比OLV-PCV高（P〈0．05或P〈0．01）；OLV．PCV的PaO2较OLV-VCV高（P〈0．01），三种通气的VT、Sa02、PET，CO2、PaCO2差异无统计学意义（P〉0．05）。结论单肺定压通气效果优于单肺定容通气。     

Mouth-to-mouth ventilation is superior to mouth-to-pocket mask and bag-valve-mask ventilation during lifeguard CPR: a randomized study

Aim

The quality of cardiopulmonary resuscitation (CPR) is a crucial determinant of outcome following cardiac arrest. Interruptions in chest compressions are detrimental. We aimed to compare the effect of mouth-to-mouth ventilation (MMV), mouth-to-pocket mask ventilation (MPV) and bag-valve-mask ventilation (BMV) on the quality of CPR.

Materials and methods

Surf lifeguards in active service were included in the study. Each surf lifeguard was randomized to perform three sessions of single-rescuer CPR using each of the three ventilation techniques (MMV, MPV and BMV) separated by 5 min of rest. Data were obtained from a resuscitation manikin and video recordings.

Results

A total of 60 surf lifeguards were included (67% male, 33% female, mean age 25 years). Interruptions in chest compressions were significantly reduced by MMV (8.9 ± 1.6 s) when compared to MPV (10.7 ± 3.0 s, P < 0.001) and BMV (12.5 ± 3.5 s, P < 0.001). Significantly more effective ventilations (visible chest rise) were delivered using MMV (91%) when compared to MPV (79%, P < 0.001) and BMV (59%, P < 0.001). The inspiratory time was longer during MMV (0.7 ± 0.2 s) and MPV (0.7 ± 0.2 s, P < 0.001 for both) compared to BMV (0.5 ± 0.2 s). Tidal volumes were significantly lower using BMV (0.4 ± 0.2 L) compared to MMV (0.6 ± 0.2 L, P < 0.001) and MPV (0.6 ± 0.3 L, P < 0.001), whereas no differences were observed when comparing MMV and MPV.

Conclusion

MMV reduces interruptions in chest compressions and produces a higher proportion of effective ventilations during lifeguard CPR. This suggests that CPR quality is improved using MMV compared to MPV and BMV.     

Comparison of automated and manual ventilation in a prehospital pediatric model

Objective. Portable transport ventilators (TV) and demand valves (DV) may be effective and easy-to-use alternatives to bag-valve (BV) for prehospital ventilation of adults. The purpose of the study was to determine whether such devices maintain arterial blood gases and airway pressures similar to those for BV in a pediatric swine model. Method. This study was a prospective, randomized, crossover design using immature swine (9.6 ± 0.9 kg) to model ventilation in small children. Anesthetized, intubated, paralyzed, and cannulated animals were ventilated initially on standard mechanical hospital ventilation (HV). They were then assigned in random order to 10-minute intervals of ventilation using BV, TV, low-frequency jet ventilation (JV), and DV. Data were analyzed using repeated-measures ANOVA and Tukey multiple comparisons (alpha = 0.05). Results. The PaO₂ exceeded 90 mm Hg for all animal/ventilation combinations. Blood PaCO₂ was lower for BV and DV than it was for TV, JV, or HV. In contrast, blood pH was higher for BV and DV than it was for TV, JV, or HV. Peak airway pressure was higher for BV than it was for HV, TV, or JV; it was lower for JV than it was for HV, TV, or BV. Conclusion. This animal model suggests that automated TV and JV may provide more effective ventilation of children than do manual BV or DV devices. Although promising, these findings require application in children under prehospital emergent conditions.     

Noninvasive pressure support versus proportional assist ventilation in acute respiratory failure

Background Although conventional pressure ventilation (PSV) decreases the rate of intubation in acute respiratory failure, patient-ventilator dyssynchrony is a frequent cause of failure. In proportional assist ventilation (PAV), pressure is applied by the ventilator in proportion to the patient-generated volume and flow; therefore, there is automatic synchrony between the patient's effort and the ventilatory cycle.Objective The aim of this study was to compare the effects of PSV and PAV during noninvasive ventilation in the treatment of acute respiratory failure.Design Prospective randomised study.Setting A multidisciplinary 24-bed intensive care unit of an acute-care teaching hospital in Alicante, Spain.Patients This study included 117 consecutive adult patients with acute respiratory failure randomised to noninvasive ventilation delivered by PSV (n = 59) or PAV (n = 58).Measurements and results There were no statistically significant differences between patients assigned to each mode of ventilation with regard to baseline parameters and aetiological diagnoses of acute respiratory failure. With regard to outcome data, no significant differences were observed between PSV and PAV in the frequency of intubation (37% vs 34%), mortality rate (29% vs 28%), and mean length of stay. Subjective comfort (0–10 visual analogue scale) was rated higher and intolerance occurred less frequently (3.4% vs 15%, P = 0.03) in the PAV than in the PSV mode.Conclusions Although PAV seems more comfortable and intolerance occurred less frequently, no major differences exist in terms of physiological improvement or in terms of outcomes when comparing PSV and PAV.An editorial regarding this article can be found in the same issue ()     

Performance of noninvasive ventilation modes on ICU ventilators during pressure support: a bench model study

Objective Noninvasive ventilation (NIV) is often applied with ICU ventilators. However, leaks at the patient-ventilator interface interfere with several key ventilator functions. Many ICU ventilators feature an NIV-specific mode dedicated to preventing these problems. The present bench model study aimed to evaluate the performance of these modes. Design and setting Bench model study in an intensive care research laboratory of a university hospital. Methods Eight ICU ventilators, widely available in Europe and featuring an NIV mode, were connected by an NIV mask to a lung model featuring a plastic head to mimic NIV conditions, driven by an ICU ventilator imitating patient effort. Tests were conducted in the absence and presence of leaks, the latter condition with and without activation of the NIV mode. Trigger delay, trigger-associated inspiratory workload, and pressurization were tested in conditions of normal respiratory mechanics, and cycling was also assessed in obstructive and restrictive conditions. Results On most ventilators leaks led to an increase in trigger delay and workload, a decrease in pressurization, and delayed cycling. On most ventilators the NIV mode partly or totally corrected these problems, but with large variations between machines. Furthermore, on some ventilators the NIV mode worsened the leak-induced dysfunction. Conclusions The results of this bench-model NIV study confirm that leaks interfere with several key functions of ICU ventilators. Overall, NIV modes can correct part or all of this interference, but with wide variations between machines in terms of efficiency. Clinicians should be aware of these differences when applying NIV with an ICU ventilator. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

A comparison of continuous positive pressure ventilation,combined high frequency ventilation and airway pressure release ventilation on experimental lung injury

In pigs with oleic induced lung injury, the effectiveness of combined high frequency ventilation (CHFV, with VDR-Phasitron) and airway pressure release ventilation (APRV) were compared to continuous positive pressure ventilation (CPPV) in a randomized study. The respiratory rate was 15/min, CPAP 8 mmHg and FiO₂ 0.25. PaCO₂ was maintained at 5 kPa. PaO₂ was significantly lower with APRV (12.5±3.9 kPa, CPPV: 15.8±3.9 kPa, and CHFV: 15.5±3.2 kPa). This was in accordance with the lowest peak airway pressure during APRV (20.9±4.8 mmHg, CPPV: 26.3±4.4 mmHg and CHFV: 28.2±3.7 mmHg). There was no difference in the pericardiac pressure between the 3 ventilation modes. The pressure related depressive effects on the cardiovascular function during CHFV and APRV were similar to those during CPPV. Adequate oxygenation and ventilation could be achieved with both CHFV and APRV, but these methods were not superior to CPPV.The study was supported by Instrumentariumin Tiedesäätiö     

Haemodynamic performance and weaning from mechanical ventilation following open-heart surgery

Summary In 38 patients ventilated after open-heart surgery the effect of a 20 minutes spontaneous breathing period on right atrial pressure (RAP), left atrial pressure (LAP), pulmonary artery pressure (PAP), aortic pressure (AoP), ECG and cardiac index (CI) was monitored. Arterial bloodgas analysis before and during spontaneous breathing ruled out any respiratory failure. The test period of spontaneous breathing provoked an increase in systemic and pulmonary vascular resistance. By this and by a direct aggravation of cardiac failure the work of both ventricles dropped inspite of an increase in end-diastolic ventricular pressure. If these hemodynamic effects of a spontaneous breathing test period are taken as a guide for deciding, if a patient after open-heart surgery is ready for being extubated, the need for reintubation will be extremely rare. The study encourages us to use mechanical ventilation as an additional instrument for treating heart failure even if no respiratory failure is present.