全氟化碳雾化吸入对急性呼吸窘迫综合征猪气体交换、呼吸力学和血流动力学的影响

目的探讨全氟化碳(PFC)雾化吸入对急性呼吸窘迫综合征(ARDS)猪气体交换、呼吸力学和血流动力学的影响。方法16只通过气管内吸入十六烷磺基丁二酸钠(DTG)制作的ARDS模型猪随机分为PFC治疗组和对照组。PFC治疗组在常规机械通气基础上,连接雾化器,以纯氧(氧流速3L/min)作为驱动气流推动雾化PFC治疗2h(7～8ml·kg-1·h-1);对照组在常规机械通气基础上,连接雾化器单独给予纯氧治疗2h(氧流速3L/min),在治疗期间每间隔15min测定动脉血气、血压、心率及平台压、顺应性、呼出潮气量和内源性呼气末正压(PEEPi),观察两组动物气体交换、呼吸力学和血流动力学参数的变化。结果DTG气管内吸入1h后,PFC治疗组动脉血氧分压(PaO2)从(377±55)mmHg(1mmHg=0.133kPa)下降至(56±13)mmHg[吸入气氧浓度(FiO2)100%],对照组PaO2从(383±53)mmHg下降至(49±12)mmHg(FiO2100%);PFC治疗组顺应性从(3.7±1.0)ml/cmH2O下降至(1.5±0.4)ml/cmH2O,对照组顺应性从(3.8±0.7)ml/cmH2O下降至(1.4±0.4)ml/cmH2O。PFC治疗2h后PFC治疗组PaO2上升至(189±133)mmHg,顺应性改善至(4.1±1.4)ml/cmH2O,呼出潮气量增加至(74.5±16.9)ml;对照组PaO2上升至(83±51)mmHg,顺应性改善至(2.8±1.8)ml/cmH2O,呼出潮气量增加至(50.1±4.1)ml;两组比较差异均有统计学意义(P均<0.05)。两组动物pH值、心率、血压、平台压、PEEPi和动脉血二氧化碳分压(PaCO2)比较差异均无统计学意义(P均>0.05)。结论PFC雾化吸入能明显改善ARDS家猪的氧合,提高损伤肺的顺应性,增加呼出潮气量。     

单纯氧疗与持续气道正压通气对慢性充血性心力衰竭Cheyne-Stokes呼吸的作用

目的观察并比较单纯氧疗与经鼻持续气道正压(nCPAP)通气对稳定期慢性充血性心力衰竭(CHF)患者Cheyne-Stokes呼吸的影响及疗效。方法采用前瞻、随机、交叉对照性设计。对入选患者测左室射血分数(LVEF),同时采用多导睡眠图证实是否存在Cheyne-Stokes呼吸,对存在Cheyne-Stokes呼吸者随机交叉进行整夜单纯鼻导管给氧(2L/min和4L/min)及nCPAP通气治疗[平均压力为(9·1±1·1)cmH2O]。结果共入选26例稳定期CHF患者,其中14例(53·8%)存在Cheyne-Stokes呼吸,呼吸暂停低通气指数(AHI)为(34·9±8·2)次/h,夜间最低动脉血氧饱和度(SaO2)为(76·2±4·7)%,SaO2<90%的时间占总睡眠时间百分比为(20·9±8·6)%,平均呼吸暂停低通气时间为(20·6±3·2)s,循环长度为(74·8±21·3)s,循环时间为(25·6±4·4)s。单纯鼻导管给氧(2L/min或4L/min)及nCPAP通气后,与基础状态相比,AHI降低,吸氧4L/min与nCPAP通气的效果优于吸氧2L/min;夜间最低SaO2升高;夜间SaO2<90%的时间占总睡眠时间百分比改善,以吸氧4L/min效果更佳;总睡眠时间增加,睡眠效率改善,但呼吸暂停低通气时间、循环长度及循环时间与基础状态比无明显改变。结论稳定期CHF患者Cheyne-Stokes呼吸的发生率很高,氧疗(4L/min)及nCPAP通气可作为治疗CHF患者Cheyne-Stokes呼吸的有效方法。     

侧卧位和分侧肺通气对单侧急性肺损伤犬的影响

目的观察体位和分侧肺通气对单侧急性肺损伤(ALI)犬的影响,探讨单侧ALI时合理的机械通气方式。方法健康杂种犬28只,建立盐酸所致单侧ALI,行容量控制通气(VCV),分为常规通气组(A组)、常规通气+健侧卧位组(B组)、不同步分侧肺通气组(C组)、同步分侧肺通气组(D组)。通气240min后,每组随机选取4只犬行核素显像。监测氧合、血流动力学、呼吸力学和肺损伤指标。结果(1)通气30min后B、C、D组氧合指数(PaO2/FiO2)[(277±23)、(296±31)、(299±22)mmHg,1mmHg=0.133kPa]显著高于A组[(180±25)mmHg,P均<0.01],通气60min后C、D组PaO2/FiO2[(348±34)、(343±29)mmHg]显著高于B组[(314±33)mmHg,P均<0.05]。(2)通气120min后B组静态肺顺应性(Cst)[(23±4)ml/cmH2O]较A组[(19±2)ml/cmH2O]显著改善,通气60min后C、D组左侧Cst[(11±1)、(11±1)ml/cmH2O]均较ALI状态时显著改善[(7±2)、(6±1)ml/cmH2O,P均<0.01]。(3)B、C、D组损伤侧血流/总血流(Q损伤/Q总)[(31.3±4.6)%和(27.5±1.3)%、(27.3±2.8)%]与A组比较差异均有统计学意义[(38.3±2.2)%,P均<0.01]。结论健侧卧位和分侧肺通气均能明显改善单侧ALI犬的氧合和肺的顺应性,分侧肺通气改善氧合较健侧卧位更有效,改善氧合的机制可能与影响双侧血流分布有关。     

控制性肺膨胀治疗急性呼吸窘迫综合征家兔的最佳压力选择

目的　探讨实施控制性肺膨胀 (SI)治疗急性呼吸窘迫综合征 (ARDS)的最佳复张压力。方法　采用肺泡灌洗法建立重度ARDS家兔模型 ,以 1～ 6倍的平均气道压 (Pm)作为实施SI的压力 ,屏气时间 2 0s。在SI前、SI期间及SI后 2min和 5min监测家兔血流动力学、肺力学、肺气体交换和肺损伤指标。以改善氧合和肺容积最显著、不加重肺损伤、同时对血流动力学影响最小的压力为最佳压力。结果　SI的压力达到 3Pm 以上时 ,家兔动脉血氧分压 (PaO2 )和动脉血氧饱和度明显提高。 5Pm 和6Pm 时SI前后的PaO2 差值 (ΔPaO2 )分别为 (6 5± 40 )mmHg(1mmHg =0 133kPa)和 (5 2± 2 5 )mmHg ,显著高于 1Pm[(- 5± 4)mmHg ,P <0 0 5 ]。 5Pm SI时的动态肺顺应性增加最明显 ,达 (3 0 6± 0 2 4)ml/cmH2 O ,明显高于SI前的水平 [(1 0 9± 0 18)ml/cmH2 O ,P <0 0 5 ]。 5Pm 时SI前后肺容积改变最显著 ,达到 (4 4 0± 3 1)ml/kg,明显高于 1Pm[(8 3± 0 7)ml/kg ,P <0 0 5 ]。未实施SI的ARDS家兔肺损伤评分为 6 10± 0 77,5Pm 时的肺损伤评分显著降低 (4 4 0± 1 6 6 ,P <0 0 1)。 6Pm 时则导致肺泡过度膨胀 ,加重肺损伤。随着SI的压力增加 ,家兔的平均动脉血压显著降低。结论　重度ARDS家兔实施SI的最佳压力是 5Pm(2 5～     

持续正气道压通气与双水平正气道压通气治疗急性心源性肺水肿的临床观察

目的 :观察急性心源性肺水肿患者应用无创通气的临床疗效 ,及其对循环参数的影响。方法 :4 0例急性左心衰患者 ,在传统治疗的基础上 ,随机分组给予持续正气道压通气 (CPAP =5cmH2 O)或双水平正压通气 (BiPAP10 / 4cmH2 O) ,观察 2h后患者循环参数改变 ,并记录患者对无创通气的耐受性。结果 :CPAP与BiPAP组在接受无创通气治疗前 ,年龄、心率 (HR)、平均动脉压 (mBP)、心输出量 (CO)、每搏射血量 (SV)、系统循环阻力 (TSR)、血氧饱和度 (SaO2 )等均无统计学差异 ,临床所用速尿、硝普钠剂量无统计差异。患者对CPAP治疗的耐受性明显高于BiPAP(95 %vs 6 5 % ,P=0 .0 14 ) ;分析成功进行无创通气治疗的病例 ,两组患者 2h后HR、mBP、CO、TSR与治疗前均有明显下降 ,P <0 .0 5 ,但SV无明显改变 (P >0 .0 5 )。两组患者SaO2 均有显著升高 ,CPAP组明显高于BiPAP组 (95 %vs 87% ,P <0 .0 0 1)。CPAP与BiPAP两组患者 2h后的循环参数无显著差异(P >0 .0 5 )。结论 :无创通气明显改善心源性肺水肿患者的呼吸功能 ,对患者的治疗是有益的 ,CPAP更易为患者接受。CPAP与BiPAP降低急性心衰患者的心脏前、后负荷 ,综合治疗的结果 ,CO下降明显 ,而SV变化不显著 ,两种通气模式对循环功能的影响无显著差异。     

左心辅助装置对缺血性心衰犬血浆脑钠素水平的影响

目的　研究急性缺血性左心功能不全时左心辅助装置 (LVAD)对左心功能的影响和血浆脑钠素 (BNP)变化情况。方法　将 10只健康成年犬随机分为对照组 (A)和辅助组 (B) ,两组皆以主动脉 -左心房旁路方式植入左心辅助装置 ,在阻断实验犬左冠脉前降支主干 4 0min后开放血流 ,其中仅对B组实验犬进行左心辅助。监测 6h内两组实验犬平均动脉压 (MAP)、心输出量 (CO)、左室收缩末期压(LVESP)、肺毛细血管楔压 (PCWP)、左室压力一阶导数(LVdp/dt)等血流动力学指标及血浆BNP水平变化情况。结果　开放左前降支 6h后 ,对照组实验犬 :MAP(72 2± 8 11)mmHg,LVESP (88 8± 5 4 )mmHg ,LVdp/dt 1839± 176 ,PCWP(9 6 8± 1 4 1)mmHg ,CO(0 98± 0 13)L/min ,BNP(15 3± 7 13)pg/mL。经过 6h左心辅助循环 ,辅助组实验犬各项血流动力学指标明显改善 ,MAP (87± 6 0 4 )mmHg ,LVESP(12 1 6± 2 88)mmHg ,LVdp/dt 2 5 90± 12 6 ,PCWP (6 5 6±0 5 1)mmHg ,CO(1 5 2± 0 16 )L/min ,BNP(6 2 5± 3 4 7)pg/mL基本降至正常水平。血浆BNP水平基本不受血流动力学变化影响。结论　左心辅助装置对于缺血性心衰具有良好的治疗作用 ,促进了心肌功能恢复 ,明显降低血浆BNP水平 ,血浆BNP水平可以较好地反映心肌功能状态。     

阻塞性睡眠呼吸暂停低通气综合征患者睡眠时的呼吸中枢反应性与夜间低氧血症的关系

目的　探讨阻塞性睡眠呼吸暂停低通气综合征 (OSAHS)患者夜间低氧血症与呼吸中枢反应性的关系。方法　应用动态脉搏容积血氧饱和度 (SpO2 )仪定量分析了 2 4例白天二氧化碳分压(PaCO2 )≥ 4 5mmHg(高CO2 组 ,1mmHg=0 133kPa)及 39例PaCO2 <4 5mmHg(等CO2 组 )的OSAHS患者夜间低氧血症的严重程度。进一步应用重复呼吸法测定了其中 15例患者 (等CO2 组 11例 ,高CO2 组 4例 )睡眠状态下呼吸中枢的低氧及高CO2 反应性。结果　 6 3例患者的睡眠呼吸暂停低通气指数 (AHI)平均为 (5 4± 2 1)次 /h ;夜间动态SaO2 监测发现高CO2 组与等CO2 组比较 ,每小时氧减饱和4 %以上的次数 (ODI4)为 (43± 2 3)次 /hvs (2 9± 18)次 /h ;SaO2 <90 %的时间占总睡眠时间的百分数(SIT90 )为 (39± 32 ) %vs(15± 18) % ,高CO2 组均较等CO2 组高 ;而睡眠时的最低SaO2 (LSaO2 )为 (5 6± 18) %vs (6 6± 16 ) % ,平均SaO2 (MSaO2 )为 (86± 12 ) %vs(93± 5 ) % ,均较等CO2 组低 (P <0 0 1) ,提示其夜间缺氧程度更重。在清醒状态下 ,高CO2 组及等CO2 组患者的高CO2 反应 (ΔP0 1/ΔPaCO2 )、低氧反应 (ΔP0 1/ΔSaO2 )、口腔阻断压 (P0 1)差异均无显著性 (P >0 1)。进入非快动眼睡眠 (NREM)及快动眼睡眠 (REM)后 ,高CO2 组     

不同通气模式下吸痰对呼吸力学和气体交换的影响

目的比较在压力控制通气（PCV）与容量控制通气（VCV）模式下吸痰对患者气体交换和呼吸力学的影响。方法采取自身交叉对照的方法，在PCV和VCV模式下分别对23例机械通气患者进行开放式吸痰，比较不同时间点气体交换、呼吸力学及血流动力学等指标的变化。结果在PCV模式下，吸痰后30min潮气量、顺应性分别为（6．60±1．95）mL／kg、（18±7）ml／cmH2O（1cmH2O=0．098kPa），与基础水平[（9．05±0．22）mL／kg、（24±6）ml／cmH2O]比较差异有统计学意义（F值分别为8．47、8．01，P均〈0．05）；而30min时动脉血氧分压（PaO2）、动脉血二氧化碳分压（PaCO2）分别为[（87±13）mmHg（1mmHg=0．133kPa）、（53±11）mmHg]，与0min[（113±22）mmHg、（41±10）mmHg]比较差异有统计学意义（，值分别为6．18、9．13，P均〈0．05）；在VCV模式下，吸痰后30min顺应性、气道平台压、气道峰压分别为[（18±7）ml／cmH2O、（27±8）cmH2O、（33±8）cmH2O]，与基础水平[（23±7）ml／cmH2O、（22±5）cmH2O、（27±8）cmH2O]比较差异有统计学意义（，值分别为6．83、6．97、7．08，P均〈0．05）；而30min时PaO2、PaCO2分别为（105±26）mmHg、（38±11）mmHg，与0min[（109±21）mmHg、（37±14）mmHg]比较差异无统计学意义（F值分别为1．88、1．32，P均〉0．05）；在PCV模式下，吸痰后5min心率、平均动脉压（MAP）分别为（109±20）次／min、（89±10）mmHg，与基础水平[（97±17）次／min、（83±12）mmHg]比较差异有统计学意义（F值分别为5．86、9．49，P均〈0．05）。在VCV模式下，吸痰后5min心率、MAP分别为（110±17）次／min、（87±11）mmHg，与基础水平[（96±17）次／min、（79±11）mmHg]比较差异有统计学意义（F值分别为7．33、7．96，P均〈0．05）。结论吸痰在PCV和VCV模式下均引起患者气体交换受损和顺应性下降，但对气体交换的影响在PCV模式下比VCV更严重和持久。     

应用肺动态压力-容积曲线低位转折点选择最佳呼气末正压的研究

目的探讨根据动态肺压力-容积曲线低位转折点压力(Pinf)选择急性呼吸窘迫综合征(ARDS)患者最佳呼气末正压(PEEP)的可行性.方法以8例早期ARDS患者为研究对象,测定动态肺压力-容积曲线及Pinfd.采用低流速法测定准静态肺压力-容积曲线,并确定静态肺压力-容积曲线低位转折点压力(Pinfs).调整PEEP水平,观察患者血流动力学、肺机械力学和氧代谢的变化.结果当PEEP从Pinfd-6cmH2O水平增加到Pinfd+6cmH2O时,动脉血氧分压、动脉血氧饱和度、气道平均压和气道峰压均显著增加.与Pinfd+6cmH2O比较,Pinfd-4cmH2O时的动态肺顺应性显著增高.Pinfd+6cmH2O时的心脏指数有降低趋势,Pinfd-4cmH2O时的氧输送有升高趋势.当Pinfd为(12.8±3.2)cmH2O,Pinfs为(11.0±3.2)cmH2O,两者具有正相关性(r=0.99,P《0.05).回归方程为Pinfd=1.66+1.01×Pinfs.结论当ARDS患者行机械通气治疗时,Pinfd-4cmH2O或Pinfs-2cmH2O为最佳PEEP,可获得最大氧输送.     

睡眠呼吸暂停综合征患者氧亲和力的变化

目的 :了解睡眠呼吸暂停综合征 (SAS)患者P50 (即血红蛋白氧饱和度 5 0 %时相应的氧分压 )是否有改变 ,探讨P50 与夜间血氧饱和度的相关性以及P50 可否预测SAS患者的病情严重程度。方法 :随机选择SAS患者 5 6例 ,其平均睡眠呼吸暂停 低通气指数 (AHI)为 (3 7 5 1± 2 0 2 1)次 h ,平均夜间血氧饱和度为 86 5 2 %± 1 91% ,清醒时的血氧饱和度为 95 2 0 %± 1 40 % ,并选择正常人 42例作为对照组进行P50 水平的测试。 11例患者经持续气道正压通气 (CPAP)治疗后重复进行测试。结果 :1 SAS患者日间P50 值为 (2 9 2 7± 1 3 1)mmHg(1mmHg=0 13 3kPa) ,对照组为 (2 7 63± 1 0 1)mmHg,二者存在显著性差异 (P <0 0 5 ) ;2 SAS患者P50 与夜间平均血氧饱和度呈明显负相关 (r=- 0 962 1,P <0 0 5 ) ;3 11例SAS患者经CPAP治疗 3个月后 ,P50 水平显著下降至 (2 7 2 7± 0 63 )mmHg,与正常对照组相比无显著性差异。结论 :1 SAS患者的氧离曲线右移 ,这可能是对组织低氧的一个保护性机制 ,以延迟肺动脉高压的形成 ,红细胞的增多及其它器官系统并发症的发生。 2 P50 能够反映SAS患者夜间低氧的严重程度 ,因而可以作为一个常规指标进行检测     

Rapid flow rates for the resuscitation of hypovolemic shock

Nine dogs were hemorrhaged to approximately 40% of their blood volume and then were resuscitated with a crystalloid solution (Normosol) at various flow rates. Three study groups with three dogs in each group were resuscitated at 15 mL/min/kg (Group 1), 6 mL/min/kg (Group 2), and 4 mL/min/kg (Group 3). Central venous pressure (CVP), pulmonary artery wedge pressure (PAWP), mean arterial pressure, and cardiac output (CO) were monitored during the hemorrhage and the resuscitation from shock. During the infusion of fluids, Group 1 animals demonstrated an elevation of the PAWP of 31 mm Hg and elevation of CVP to 23.2 mm Hg; CO rose to 8.4 L/min. In Group 2 animals CO rose to 6.1 L/min; CVP was 10.5 mm Hg; and PAWP was 25 mm Hg. Group 3 animals had a rise in CO to 5 L/min; CVP and PAWP rose to 4.5 mm Hg and 6.8 mm Hg, respectively. In this experimental shock study, infusion of crystalloids at 6 mL/min/kg appeared to result in an improved physiologic response, although no statistical difference was demonstrated. Further studies are necessary to demonstrate the optimum flow rate for resuscitation of hypovolemic shock using crystalloids.     

Hemodynamic effects of bilevel nasal positive airway pressure ventilation in patients with heart failure

AIMS: Benefits of nasal continuous positive airway pressure (CPAP) in patients presenting with chronic heart failure (CHF) are controversial. The purpose of this study was to compare the hemodynamic effects of CPAP and bilevel positive airway pressure (BiPAP) in patients with or without CHF. METHODS AND RESULTS: Twenty patients with CHF and 7 with normal left ventricular function underwent cardiac catheterization. Measurements were made before and after three 20-min periods of BiPAP: expiratory positive airway pressure (EPAP) = 8 cm H2O and inspiratory positive airway pressure (IPAP) = 12 cm H2O, EPAP = 10 cm H2O and IPAP = 15 cm H2O, and CPAP = EPAP = IPAP = 10 cm H2O administered in random order. Positive pressure ventilation decreased cardiac output (CO) and stroke volume. No change was observed in either pulmonary or systemic arterial pressure. There was no difference in the hemodynamic effects of the three ventilation settings. Only mean pulmonary wedge pressure (MPWP) and heart rate were lower with CPAP than with BiPAP. CO decreased only in patients with low MPWP (相似文献   

Esophageal pressure monitoring: a practical adjuvant to hemodynamic monitoring with positive end-expiratory pressure

With positive end-expiratory pressure (PEEP)-induced reduction in cardiac output, measurement of ventricular filling pressure assists in proper therapeutic decision-making. Because PEEP may increase pleural and juxtacardiac pressure, central venous pressure (CVP) and left atrial pressure (LAP) measurements during PEEP may not simply reflect ventricular filling, but rather reflect the sum of intracardiac and extracardiac forces. Monitoring devices placed within the central circulation use saline solution-filled lumens and transducer systems for pressure monitoring. Therefore, any device designed to estimate the extracardiac influence of PEEP on intraluminal monitoring devices would be expected to reflect such changes best when the device is also filled with saline solution. In the present study, esophageal pressure (Pes) was measured with a saline solution-filled balloon-equipped nasogastric tube to estimate the extracardiac influence of PEEP on CVP and LAP. Pes, CVP, LAP, and cardiac index (CI) were measured in 17 patients subjected to 0, 5, 10, 15, 20 cm H2O PEEP. Comparing 0 with 20 cm H2O PEEP, CVP (7 +/- 1.0 mm Hg to 13.4 +/- 1.3 mm Hg), LAP (6.3 +/- 1.1 mm Hg to 11.7 +/- 1.4 mm Hg), and Pes (6.1 +/- 1.4 mm Hg to 12.1 +/- 1.5 mm Hg) all increased significantly as CI fell (2.72 +/- 0.14 L/min/m2 to 2.20 +/- 0.15 L/min/m2).(ABSTRACT TRUNCATED AT 250 WORDS)     

分侧肺通气时不同呼气末正压和潮气量对单侧肺损伤犬循环的影响

目的 观察不同步分侧肺通气和同步分侧肺通气对单侧急性肺损伤(ALI)犬循环的影响.方法 取健康杂种犬12只,建立盐酸所致单侧肺损伤动物模型,行容积控制通气,将犬按随机数字表法分为不同步分侧肺通气组(NS组)和同步分侧肺通气组(S组).参数:患侧潮气量3.5 ml/kg保持不变,呼气末正压(PEEP)选择15、20、25 cm H2O(1 cm H2O=0.098 kPa);患侧PEEP 10 cm H2O不变,潮气量用随机数字表法选择5、7.5、10 ml/kg.健侧通气参数始终不变,检测不同通气条件下两组犬血流动力学和氧动力学指标.结果 (1)患侧潮气量3.5 ml/kg不变,PEEP为15、20 cm H2O时,两组血流动力学和氧动力学参数差异无统计学意义.当患侧PEEP为25 cm H2O时,NS组心率、体循环平均压(mABP)、心输出量、氧合指数和混合静脉血氧饱和度(SvO2)分别为(98±8)次/min、(84±6)mm Hg(1 mm Hg=0.133 kPa)、(1.10±0.13)L/min、(199±14)mm Hg和(55±6)%,明显低于S组[分别为(124±9)次/min、(103±7)mm Hg、(1.52±0.28)L/min、(221±15)mm Hg和(62±4)%,t值分别为-7.852、-16.561、-15.043、-13.314和-5.653,均P＜0.01].(2)患侧PEEP 10 cm H2O不变,潮气量分别为5、7.5 ml/kg时,两组的血流动力学和氧动力学参数比较差异无统计学意义.当患侧潮气量为10 ml/kg时,NS组HR、mABP、心输出量、氧合指数和SvO2均低于S组(均P＜0.01).结论 在本实验动物模型中,患侧与健侧所用PEEP水平相差≤20 cm H2O或患侧潮气量≤7.5 ml/kg时,同步和非同步分侧肺通气均能保持循环稳定.若需要更高水平PEEP时,建议选用同步分侧肺通气.     

肥胖通气低下综合征呼吸中枢反应性的改变与二氧化碳潴留相关作用

目的 观察肥胖通气低下综合征患者呼吸中枢反应性的改变与二氧化碳（ＣＯ２）潴留的相关作用。方法 测定了５例白天动脉血二氧化碳分压（ＰａＣＯ２）〉４５ｍｍＨｇ的睡眠呼吸暂停综合征（ＳＡＳ）患者呼吸中枢柢氧反应性（△Ｐ０．１／△ＳａＯ２ｗ、△Ｖｅ／△ＳａＯ２）及高ＣＯ２反应性（△Ｐ０．１／△ＰａＣＯ２、△Ｖｅ／△ＰａＣＯ２）,并选择５例年龄、性别、身高、体重、呼吸暂停病程及睡眠呼吸率乱指数（ＡＨＩ）相近     

肺移植对5例慢性阻塞性肺疾病患者肺功能的影响

目的研究单肺移植手术治疗慢性阻塞性肺疾病(COPD)对呼吸生理及肺功能的影响。方法5例患者均为Ⅳ级COPD男性患者,年龄51～63岁。术前2周测定患者用力肺活量(FVC)、第一秒用力呼气容积(FEV1)、FEV1/FVC、最大通气量(MVV)、残气容积(RV)、肺总量(TLC)、残总比(RV/TLC)、深吸气量(IC)、胸腔气体容积(TGV)、呼气峰流量(PEF)、总气道阻力(Rawtotal)、肺一氧化碳弥散量(DLCO)、每升肺泡容积肺一氧化碳弥散量(DLCO/V·A)、6分钟行走距离(6MWD)、动脉血氧分压(PaO2)、肺泡气动脉血氧分压差[P(Aa)O2]、动脉血氧饱和度(SaO2)、动脉血二氧化碳分压(PaCO2)及平均肺动脉压(mPAP)等参数。术后2个月再行上述测定。结果5例患者术前2周、术后2个月检测的参数为MVV(23.6±5.8)、(71.6±21.8)L,FEV1(0.68±0.21)、(1.85±0.46)L,FEV1/FVC(37.4±8.3)、(75.6±13.9)%,PaO2(60.0±9.1)、(86.2±2.9)mmHg(1mmHg=0.133kPa),SaO2(90.0±4.6)%、(96.8±0.5)%及mPAP(31.2±5.5)、(16.6±1.8)mmHg,均有显著改善(P均<0.05);3例患者IC[(1.16±0.26)、(1.83±0.35)L]、TGV[(6.52±0.27)、(4.52±0.29)L]、RV[(5.12±0.39)、(3.20±0.32)L]、RV/TLC[(71.0±5.6)、(51.3±2.5)%]及Rawtotal[(6.62±0.99)、(2.48±0.87)cmH2O·L-1·s-1]改善显著(P均<0.05);4例患者PEF[(1.65±0.40)、(3.92±1.63)L/s]、DLCO[(8.5±3.0)、(21.0±6.2)ml·min-1·mmHg-1]及6MWD[(46.8±14.7)、(246.8±51.9)m]也显著增加(P均<0.05);FVC[(1.85±0.40)、(2.45±0.49)L]、TLC[(7.19±0.15)、(6.26±0.73)L]、DLCO/V·A[(2.90±1.50)、(5.41±0.87)L·min-1·mmHg-1]、P(Aa)O2[(37.6±16.3)、(17.8±6.3)mmHg]及PaCO2[(44.6±7.7)、(37.4±3.4)mmHg]有所改善,但差异无统计学意义(P均>0.05)。结论COPD患者肺移植术后肺通气、气道阻力、残气、弥散、运动耐力及气体交换功能均明显改善。     

Decreasing hydrostatic pressure does not uniformly decrease high-pressure pulmonary edema

Pulmonary artery wedge pressure (PAWP) of 30 mm Hg with left atrial balloon inflation for 1 1/2 hours produced pulmonary edema in eight dogs. PAWP was then decreased to 10 mm Hg for two hours, and shunt, lung water (extravascular thermal volume, or ETV, by thermal dye), and perfusion distribution (radiomicrosphere technique) were measured and compared with four other dogs (group 1) whose PAWP was maintained at 10 mm Hg. The eight dogs with PAWP of 30 mm Hg for 1 1/2 hours were retrospectively subdivided into two groups of four based on ETV (group 2, double baseline ETV; group 3, triple baseline ETV). Baseline ETV and shunt were similar for all groups and remained unchanged for group 1. At 1 1/2 hours, 2 hours (1/2 hour after decreasing PAWP), 2 1/2 hours, and 3 1/2 hours, respectively, ETV were: 13.9 +/- 1.9, 12.8 +/- 2.0, 9.3 +/- 1.5, and 8.5 +/- 1.0 ml/kg in group 2; and 21.9 +/- 2.1, 22.7 +/- 2.2, 22.5 +/- 2.0, and 22.2 +/- 2.0 ml/kg in group 3. A more variable rate of edema formation was detected in eight additional dogs, but failure to resolve higher levels of edema after decreasing PAWP was also demonstrated in this group. Edema was greatest in lower lobes and decreased lobar perfusion. Shunt was higher in group 3 than in group 2 at 1 1/2 hours and decreased in group 2 but not in group 3 at 3 1/2 hours. Changes in colloid osmotic pressure may account for the differences in edema formation and resolution, but our data suggest that, independent of the rate of edema formation, a decrease in vascular exchange surface area at higher levels of edema may inhibit edema resolution when PAWP is decreased.     

Enhancement of Cardiac Performance by Bilevel Positive Airway Pressure Ventilation in Heart Failure

BackgroundRecent studies have reported the clinical usefulness of positive airway pressure ventilation therapy with various kinds of pressure support compared with simple continuous positive airway pressure (CPAP) for heart failure patients. However, the mechanism of the favorable effect of CPAP with pressure support can not be explained simply from the mechanical aspect and remains to be elucidated.Methods and ResultsIn 18 stable chronic heart failure patients, we performed stepwise CPAP (4, 8, 12 cm H₂O) while the cardiac output and intracardiac pressures were continuously monitored, and we compared the effects of 4 cm H₂O CPAP with those of 4 cm H₂O CPAP plus 5 cm H₂O pressure support. Stepwise CPAP decreased cardiac index significantly in patients with pulmonary arterial wedge pressure (PAWP) <12 mm Hg (n = 10), but not in those with PAWP ≥12 mm Hg (n = 8). Ventilation with CPAP plus pressure support increased cardiac index slightly but significantly from 2.2 ± 0.7 to 2.3 ± 0.7 L min^?1 m^?2 (P = .001) compared with CPAP alone, regardless of basal filling condition or cardiac index.ConclusionsOur results suggest that CPAP plus pressure support is more effective than simple CPAP in heart failure patients and that the enhancement might be induced by neural changes and not simply by alteration of the preload level.     

Continuous positive airway pressure treatment improves pulmonary hemodynamics in patients with obstructive sleep apnea.

Daytime pulmonary hypertension (PH) is relatively common in obstructive sleep apnea (OSA) and is thought to be associated with pulmonary vascular remodeling (PRm). The extent to which PH is reversible with treatment is uncertain. To study this, we measured pulmonary hemodynamics (Doppler echocardiography) in 20 patients with OSA (apnea-hypopnea index [AHI] 48.6 +/- 5.2/h, mean +/- SEM) before and after 1 and 4 mo of CPAP treatment (compliance 4.7 +/- 0.5 h/night). Patients had normal lung function, and no cardiac disease or systemic hypertension. Doppler studies were performed at three levels of inspired oxygen concentration (11%, 21%, and 50%) and during incremental increases in pulmonary blood flow (10, 20, and 30 microg/kg/min dobutamine infusions). Treatment resulted in a decrease in pulmonary artery pressure (Ppa, 16.8 +/- 1.2 mm Hg before CPAP versus 13.9 +/- 0.6 mm Hg after 4 mo CPAP, p < 0.05) and total pulmonary vascular resistance (231.1 +/- 19.6 versus 186.4 +/- 12.3 dyn. s. cm(-)(5), p < 0.05). The greatest treatment effects occurred in the five patients who were pulmonary hypertensive at baseline. The pulmonary vascular response to hypoxia decreased after CPAP (DeltaPpa/DeltaSa(O(2)) 10.0 +/- 1.6 mm Hg before versus 6.3 +/- 0.8 mm Hg after 4 mo CPAP, p < 0.05). The curve of Ppa versus cardiac output (Q), derived from the incremental dobutamine infusion, shifted downward in a parallel fashion during treatment. Systemic diastolic blood pressure also fell significantly. Improvements in pulmonary hemodynamics were not attributable to changes in left ventricular diastolic function or Pa (O(2)). We conclude that CPAP treatment reduces Ppa and hypoxic pulmonary vascular reactivity in OSA and speculate that this may be due to improved pulmonary endothelial function.     

部分液体通气治疗急性肺损伤家兔

目的 观察部分液体通气（ＰＬＶ）对急性肺损伤（ＡＬＩ）家兔肺内气体交换、肺顺应性、体循环功能的影响。方法 健康雄性新西兰兔２４只,用油酸制备成急性肺损伤模型后随机分为３组,每组８只。各组采用不同方法治疗：呼气末正压（ＰＥＥＰ）组,常规机构通气（ＣＭＶ）＋ＰＥＥＰ治疗;生理盐水（ＮＳ）组,肺内注入ＮＳ同时＋ＣＭＶ＋ＰＥＥＰ;ＰＤＣ组,肺内注入全氟碳化合物－全氟萘烷（ＦＤＣ）同时＋ＣＭＶ＋ＰＥＥＰ。分