双水平压力调节通气与反比通气对健康及急性肺损伤犬心肺功能影响的比较研究

目的 :比较双水平压力调节 (BIPAP)通气和反比通气 (IRV)对心肺功能的影响。方法 :在两种通气模式 0、0 .5和 1.0 k Pa呼气末压 (EEP)时 ,分别测定健康犬及油酸诱发急性肺损伤犬的呼吸力学、血流动力学及血气分析各参数。结果 :无论有无急性肺损伤 ,BIPAP通气时平均气道压 (m Paw )均明显低于 IRV时(P均 <0 .0 5 )。给健康犬用 IRV通气时 ,上述 3种 EEP水平的 m Paw分别为 (0 .437± 0 .10 3) k Pa、(0 .811±0 .0 93) k Pa和 (1.36 0± 0 .119) k Pa;用 BIPAP通气时则分别降为 (0 .2 2 5± 0 .0 71) k Pa、(0 .6 11± 0 .10 5 ) k Pa和(1.10 7± 0 .0 89) k Pa。油酸诱发急性肺损伤后 ,m Paw分别由 IRV时 (0 .72 5± 0 .2 2 2 ) k Pa、(1.186± 0 .2 98) k Pa和 (1.6 0 0± 0 .10 0 ) k Pa降至 BIPAP时 (0 .35 0± 0 .12 9) k Pa、(0 .6 2 5± 0 .15 0 ) k Pa和 (1.12 5± 0 .0 96 ) k Pa;但两种通气模式中气道峰压、心排血量并无明显差异。另外 ,急性肺损伤时 ,BIPAP通气的动脉血氧分压 (Pa O2 )分别为 (9.10± 1.79) k Pa、(11.43± 1.80 ) k Pa和 (13.40± 3.2 0 ) k Pa,较 IRV时 Pa O2 (7.87± 2 .33) k Pa、(9.0 7±3.0 5 ) k Pa和 (9.71± 1.85 ) k Pa增高 (EEP 1.0 k Pa时 ,P <0 .0 5 )。结论 :     

间歇负压通气对实验犬通气和血流动力学的影响

目的：观察间歇负压通气时通气压力对实验犬的通气和血流动力学的影响。方法：通过实验犬股静脉插入Swan-Ganz漂浮导管,比较不同负压水平时实验犬的潮气量和血流动力学的变化。结果：间歇负压通气能够增加实验犬潮气量,但对血流动力学无影响。结论：间歇负压通气是一种安全、无创和有效的通气方式。     

病理状态下颅内静脉窦压与颅内压的相关性研究

目的探讨病理状态下颅内静脉窦压与颅内压的关系。方法选择100例中重型颅脑损伤住院患者,收集其颅内静脉窦压及颅内压的相关数据,并进行相关性分析。结果在颅脑损伤早期,颅内压低于4．0kPa时,颅内压与颅内静脉窦压呈正相关（r=0．577,P〈0．001）。随着颅内压的逐步升高,颅内静脉窦压增加并不明显,出现一相对的平台期,当颅内压上升至6．25kPa时。颅内静脉窦压反较平台期略有下降。结论在颅脑损伤早期,颅内压与颅内静脉窦压存在一压力梯度,保持颅内静脉的通畅对控制颅内压的升高十分重要。     

无创双相正压通气对正常人血流动力学的影响

目的 :为了解无创双相正压通气 (BiPAP)对正常人血流动力学的影响。方法 :对2 2例正常自愿者进行研究 ,测定正常人在不同压力水平 (10 /4cmH2 O、 2 0 /10cmH2 O)的通气状态时及通过鼻罩或口鼻面罩通气时的心率、血压、心脏指数。结果 :1)虽然在某种通气方式时心率、血压的变化有统计差异 ,这种差异通过普通的临床监护设备并不能引起临床医师的注意 ;2 )正压通气使实验者的心脏指数下降 ,而且其下降程度与正压通气的压力正相关 ,心脏指数的下降主要由于心脏每搏指数的下降所致 ,心率的变化不是主要原因。结论 :临床工作中应综合评价BiPAP对患者的呼吸、循环功能的影响。     

机械通气对CVP的影响

目的探讨机械通气对CVP的影响 ,提高机械通气病人CVP的准确性和可靠性。方法对 40例机械通气病人进行CVP及机械通气有关参数的监测。结果经监测比较发现 ,机械通气使CVP上升。CVP的上升与平均气道压呈正相关。结论CVP的这种变化并不反映相伴随的血液动力学变化。     

反比通气应用于硬质气管镜诊疗的效果观察

目的 观察反比通气（IRV）应用于硬质气管镜诊疗的效果。方法 选择接受无痛硬质气管镜诊疗的患者50例,随机分为A组（IRV组）和B组（对照组）,均行常频喷射通气,A组吸呼比2∶1,B组吸呼比1∶2,余呼吸参数两组设置相同（喷射氧浓度100%,喷射频率20次/min,驱动压0.05～0.15 MPa）。比较T₀（麻醉前）、T₁（操作开始后10 min）、T₂（操作开始后20 min）和T₃（操作开始后30 min）时点患者的动脉血气［包括：酸碱度（pH）、动脉血氧分压（PaO₂）、动脉血二氧化碳分压（PaCO₂）］、心率（HR）、平均动脉压（MAP）和达到理想呼吸幅度时的呼吸机驱动压,以及经皮动脉血氧饱和度（SpO₂）< 95%、术中低氧血症（SpO₂ < 90%）和循环不稳定事件的发生率。结果 A组呼吸机驱动压低于B组,SpO₂ < 95%发生率低于B组,两组患者T₁、T₂和T₃时点的PaO₂高于T₀时点,两组患者T₂和T₃时点的HR和MAP低于T₀时点,差异均有统计学意义（P < 0.05）;两组间各时点HR、MAP、PaO₂、pH和PaCO₂比较,差异均无统计学意义（P > 0.05）。结论 IRV应用于硬质气管镜诊疗,可有效降低驱动压,减少气压伤发生的风险,同时可改善氧合,且不会造成CO₂蓄积,患者血流动力学稳定,在临床上是安全、可行的。     

The effects of dihydroergotamine in patients with head injury and raised intracranial pressure

In the first study 6 patients with raised intracranial pressure due to brain oedema following head injury were given dihydroergotamine because of low perfusion pressure. The intracranial pressure fell simultaneously with the increase in arterial pressure. The intracranial pressure fell from 24±2 mmHg by a maximum of 12±1 mmHg after a single intravenous injection of 0.25 mg of dihydroergotamine and remained at a low level for 35–70 min before stabilizing at a new level 5±1 mmHg below the baseline. The initial rapid and marked decrease in intracranial pressure may be the result of a reduced intracranial blood volume, due predominantly to constriction of the more voluminous venous capacitance vessels (by analogy with the corresponding vascular effect of dihydroergotamine on skeletal muscle and skin.) In the second study, experiments using sympathectomized cat skeletal muscle, showed that dihydroergotamine also reduced the hydrostatic capillary pressure, inducing absorption of fluid from the interstitial tissue to blood. It is suggested that a similar transcapillary absorption effect in the damaged brain may be an explanation for the observation that the intracranial pressure stabilized at a level below the initial one following dihydroergotamine.     

压力支持通气与成比例压力支持通气模式对血流动力学状态的影响

目的　探讨压力支持通气 (PSV)与成比例压力支持通气 (PPS)不同通气模式对血流动力学的影响。方法　选择呼吸衰竭行机械通气及脉搏轮廓法持续血流动力学监护患者 2 6例。经治疗进入低辅助通气后比较在PSV、PPS两种通气模式下血流动力学及呼吸力学的差异。结果　PPS模式心输出量 (CO)、心指数 (CI)、每搏量 (SV)较PSV模式明显增加 (P <0 0 5 ) ,外周血管阻力 (SVR)无明显变化 (P >0 .0 5 ) ,气道峰压 (Ppeak)及内源性PEEP(PEEPi)明显下降 (P <0 .0 5 )。结论　PPS模式对机械通气患者的血流动力学状态影响最小 ,较适用于血流动力学不稳定患者。     

颅内压与脑灌注压持续监护在急性颅内血肿救治中的应用价值

目的 探讨颅内压（ＩＣＰ）和脑灌注压（ＣＰＰ）监护在急性颅内血肿救治中价值。方法 选择两组病人进行病例对照研究。监护组：对６５例急性颅内血肿患者进行了持续ＩＣＰ监测和ＣＰＰ监测根据监测结果进行治疗；非监护组：６５例病情相似的患者按常规治疗，不做ＩＣＰ监测和ＣＰＰ监测。结果 监护组６５例在治疗前ＩＣＰ均增高。５６例ＣＰＰ降低；ＩＣＰ和ＣＰＰ数值高低与治疗效果有比较密切的关系。两组病人治疗效果有明显差别，监护组死亡率１２．３％，非监护组２０％，监护组人均甘露醇用量、电解质紊乱及少尿型肾衰发生率均低于非监护组。结论 ＩＣＰ和ＣＰＰ监护在颅内血肿救治中具有积极意义。可以明显提高治疗效果。减少脱水剂用量及相关并发症。     

A simplified technique for measuring intracranial pressure

A new technique for the measurement of intracranial pressure is described and a prospective study of patients treated with such monitoring reported.     

Clinical experience with a fiberoptic intracranial pressure monitor

Retrospective clinical experience with our first 46 patients monitored with a fiberoptic intracranial pressure device is described. In 43 of 46 patients, the transducer was introduced into brain parenchyma. A ventriculostomy system was used in 3 of 46 patients. The monitoring system was generally characterized by ease of placement and system maintenance and by technical simplicity. Several problems were encountered, including breakage of system components (12%), erroneous readings requiring transducer repositioning (8.6%), epidural hematoma (3.4%), and infection (1.7%). No infections or hematomas occurred in the 3 cases in which the ventriculostomy system was used. Overall, our experience with the Camino intracranial pressure fiberoptic monitoring system confirms previous reports of its favorable features.     

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     

外源性呼气末正压对气道压力的影响

目的探讨外源性呼气末正压（PEEP）对气过压力影响的规律。方法通过模拟肺（静态顺应性为28ml／cmH2O,气道阻力为0．8cmH2O·L－1·S-1）试验,设置不同的PEEP,观察气道压力（修压、平均压、平台压）的变化。结果外源性PEEP从0增加至3cmH2O时,气过压力增幅最大,平均每增加1cmH2OPEEP,气道峰压、平台压增加3．5～4．1cmH2O,当PEEP增加至12cmH2O时,气道峰压和平台压增加了20cmH2O以上。结论外源性PEEP对气造压力的影响,可产生一种“扩大”效应,这种“扩大”效应在低水平的PEEP时尤为显著。在使用人工机械通气时,如需设置外源性PEEP时,必须严密监测气道压力的变化,以防止肺损伤。     

不同方法测量的颅内压值之差异

目的　比较在急性颅脑损伤患者使用不同方法测量的颅内压值 (intracranialpressure ,ICP)之差异。方法　 1 6例急性颅脑损伤在术后同时采用硬脑膜外压 (extraduralpressure ,EDP)监护、脑室内脑脊液压力 (ventnricle cerebrosinalfluidpressure,V CSFP)和腰蛛网膜下腔脑脊液压力 (lumber subarachnoidspaceCSFP ,L CSFP)方法测量ICP值 ,每天一次 ,共 6d。结果　V CSFP与L CSFP所测量的ICP值相似 ,而在多数时间段 ,EDP测量的ICP值低于上述两种方法的ICP值 ,有统计学差异 (P <0 0 5 )。结论　EDP测量的ICP值可能与V CSFP与L CSFP测量的ICP值有差异     

Clinical review: Biphasic positive airway pressure and airway pressure release ventilation

This review focuses on mechanical ventilation strategies that allow unsupported spontaneous breathing activity in any phase of the ventilatory cycle. By allowing patients with the acute respiratory distress syndrome to breathe spontaneously, one can expect improvements in gas exchange and systemic blood flow, based on findings from both experimental and clinical trials. In addition, by increasing end-expiratory lung volume, as occurs when using biphasic positive airway pressure or airway pressure release ventilation, recruitment of collapsed or consolidated lung is likely to occur, especially in juxtadiaphragmatic lung legions. Traditional approaches to mechanical ventilatory support of patients with acute respiratory distress syndrome require adaptation of the patient to the mechanical ventilator using heavy sedation and even muscle relaxation. Recent investigations have questioned the utility of sedation, muscle paralysis and mechanical control of ventilation. Furthermore, evidence exists that lowering sedation levels will decrease the duration of mechanical ventilatory support, length of stay in the intensive care unit, and overall costs of hospitalization. Based on currently available data, we suggest considering the use of techniques of mechanical ventilatory support that maintain, rather than suppress, spontaneous ventilatory effort, especially in patients with severe pulmonary dysfunction.     

无创正压通气与有创正压通气治疗急性呼吸衰竭的比较研究

目的　比较无创正压通气 (NPPV)和有创正压通气 (IPPV)救治急性呼吸衰竭 (ARF)的临床效果 ,评估NPPV在ARF治疗中的作用。方法　将各种原因所致ARF 5 2例患者随机分为NPPV组 (2 6例 )和IPPV组 (2 6例 ) ,在给予病因治疗同时分别实施NPPV和IPPV。观察分析两组患者在治疗过程中动脉血气变化、并发症的发生率及治疗结果。结果　NPPV组有 7例 (2 6 .9% )治疗失败转为气管插管IPPV ,其中 4例 (15 .4 % )死亡。IPPV组死亡 5例 (19.2 % ) ,两组死亡率无显著差异 (P >0 0 5 )。两组治疗有效患者在分别接受NPPV和IPPV治疗后 6h动脉血气有相似的显著改善。NPPV组患者机械通气时间和住院时间短于IPPV组 (P <0 .0 5 )。NPPV组的并发症发生率低于IPPV组 (P <0 .0 5 )。结论　在经过选择的ARF患者中 ,应用NPPV治疗的临床效果与IPPV相似。实施NPPV可缩短机械通气和住院时间 ,减少并发症。且因为无创伤性 ,NPPV可作为经过选择的ARF患者首选的通气支持治疗手段。     

无创与有创正压通气对危重肺心病呼吸衰竭患者的疗效评价

目的　评价无创与有创正压通气在危重肺心病呼吸衰竭患者中的治疗效果。方法　 2 0例危重肺心病呼吸衰竭患者随机分为A组和B组 ,每组 10例。A组进行有创通气和常规药物治疗 ,B组进行无创通气和常规药物治疗。结果　A组进行有创通气 2 4h后 ,10例患者均明显好转 ,呼吸频率、心率下降 ,PaO2 上升 ,PaCO2 下降 ,与治疗前比较均有显著差异 (P <0 .0 1)。人工机械通气天数平均为 (9± 4 )d ,住院天数平均为 (15± 5 )d。 10例患者 9例出院 ,1例因呼吸机依赖而死亡。B组无创通气 2 4h后仅 1例治疗有效 ,4例无明显变化 ,5例病情恶化。 9例患者均在 36h之内改为有创通气 ,其中 1例在气管插管时因心跳呼吸骤停死亡 ,2例在有创通气过程中死亡 ,余 6例患者均平稳撤机。人工机械通气天数平均为 (15± 6 )d ,住院天数平均为 (2 1± 6 )d ,与A组比较有显著差异性 (P <0 .0 5 )。结论　危重肺心病呼吸衰竭患者不宜选用无创正压通气 ,应尽早气管插管进行有创通气治疗。     

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.