[呼气末正压对急性呼吸窘迫综合征患者脑血流及脑血管自动调节功能的影响]

[The influence of positive end-expiratory pressure on cerebral blood flow and cerebrovascular autoregulation in patients with acute respiratory distress syndrome].

作者信息

Yang Chunli, Chen Zhi, Lu Yuanhua, He Huiwei, Zeng Weihua

机构信息

Department of Critical Care Medicine, People's Hospital of Jiangxi Province, Nanchang 330006, Jiangxi, China. Corresponding author: Chen Zhi, Email:

出版信息

Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2014 May;26(5):335-8. doi: 10.3760/cma.j.issn.2095-4352.2014.05.010.

DOI:10.3760/cma.j.issn.2095-4352.2014.05.010

PMID:24809263

Abstract

OBJECTIVE

To explore the influence of different positive end-expiratory pressure (PEEP) levels on cerebral blood flow (CBF) and cerebrovascular autoregulation in patients with acute respiratory distress syndrome(ARDS).

METHODS

A prospective study was conducted. Moderate or severe ARDS patients admitted to Department of Critical Care Medicine of Jiangxi Provincial People's Hospital from January 1st, 2013 to October 1st, 2013 were enrolled. The changes in hemodynamics, respiratory mechanics and gas exchange under different levels of PEEP were observed. CBF velocity of middle cerebral artery (MCA) was measured using transcranial Doppler (TCD), and breath-holding index (BHI) was also calculated.

RESULTS

35 patients with ARDS were included. The oxygenation index (OI), peak inspiratory pressure (PIP), plat pressure (Pplat) and central venous pressure (CVP) were markedly elevated (OI: 324.7±117.2 mmHg vs. 173.4±95.8 mmHg, t=5.913, P=0.000; PIP: 34.7±9.1 cmH2O vs. 26.1±7.9 cmH2O,t=4.222, P=0.000; Pplat: 30.5±8.4 cmH2O vs. 22.2±7.1 cmH2O, t=4.465, P=0.000; CVP: 12.1±3.5 mmHg vs. 8.8±2.2 mmHg, t=4.723, P=0.000) when PEEP was increased from (6.4±1.0) cmH2O to (14.5±2.0) cmH2O (1 cmH2O=0.098 kPa). But no significant difference in the heart rate (85.5±19.1 beats/min vs. 82.7±17.3 beats/min, t=0.643, P=0.523), mean arterial pressure (73.5±12.4 mmHg vs. 76.4±15.1 mmHg, t=0.878, P=0.383) and CBF velocity of MCA [peak systolic flow velocity (Vmax): 91.26±17.57 cm/s vs. 96.64±18.71 cm/s, t=1.240, P=0.219; diastolic flow velocity (Vmin): 31.54±7.71 cm/s vs. 33.87±8.53 cm/s, t=1.199, P=0.235; mean velocity (Vmean): 51.19±12.05 cm/s vs. 54.27±13.36 cm/s, t=1.013, P=0.315] was found. 18 patients with BHI<0.1 at baseline demonstrated that cerebral vasomotor reactivity was poor. BHI was slightly decreased with increase in PEEP (0.78±0.16 vs. 0.86±0.19, t=1.905, P=0.061).

CONCLUSIONS

Some of moderate or severe ARDS patients without central nervous system disease have independent of preexisting cerebral autoregulation impairment. However, independent of preexisting cerebral autoregulation may not further be impaired when a high PEEP was chosen.

摘要

目的

探讨不同呼气末正压（PEEP）水平对急性呼吸窘迫综合征（ARDS）患者脑血流量（CBF）及脑血管自动调节功能的影响。

方法

进行一项前瞻性研究。纳入2013年1月1日至2013年10月1日在江西省人民医院重症医学科住院的中度或重度ARDS患者。观察不同PEEP水平下的血流动力学、呼吸力学及气体交换变化。采用经颅多普勒（TCD）测量大脑中动脉（MCA）的CBF速度，并计算屏气指数（BHI）。

结果

共纳入35例ARDS患者。当PEEP从（6.4±1.0）cmH₂O增加到（14.5±2.0）cmH₂O（1 cmH₂O = 0.098 kPa）时，氧合指数（OI）、吸气峰压（PIP）、平台压（Pplat）和中心静脉压（CVP）显著升高（OI：324.7±117.2 mmHg对173.4±95.8 mmHg，t = 5.913，P = 0.000；PIP：34.7±9.1 cmH₂O对26.1±7.9 cmH₂O，t = 4.222，P = 0.000；Pplat：30.5±8.4 cmH₂O对22.2±7.1 cmH₂O，t = 4.465，P = 0.000；CVP：12.1±3.5 mmHg对8.8±2.2 mmHg，t = 4.723，P = 0.000）。但心率（85.5±19.1次/分对82.7±17.3次/分，t = 0.643，P = 0.523）、平均动脉压（73.5±12.4 mmHg对76.4±15.1 mmHg，t = 0.878，P = 0.383）及MCA的CBF速度[收缩期峰值流速（Vmax）：91.26±17.57 cm/s对96.64±18.71 cm/s，t = 1.240，P = 0.219；舒张期流速（Vmin）：31.54±7.71 cm/s对33.87±8.53 cm/s，t = 1.199，P = 0.235；平均流速（Vmean）：51.19±12.05 cm/s对54.27±13.36 cm/s，t = 1.013，P = 0.315]差异无统计学意义。18例基线BHI<0.1的患者显示脑血管舒缩反应性较差。随着PEEP增加，BHI略有下降（0.78±0.16对0.86±0.19，t = 1.905，P = 0.061）。