体外膜肺氧合对新生羔羊脑血流动力学的影响。

Effect of extracorporeal membrane oxygenation on cerebral hemodynamics in newborn lambs.

作者信息

Rosenberg A A, Kinsella J P

机构信息

Department of Pediatrics, University of Colorado Health Sciences Center, Children's Hospital, Denver.

出版信息

Crit Care Med. 1992 Nov;20(11):1575-81.

PMID:1424702

Abstract

BACKGROUND AND PURPOSE

Neurologic injury caused by changes in cerebral blood flow is a concern in infants treated with extracorporeal membrane oxygenation (ECMO). To investigate the hypothesis that cerebral hemodynamics would be influenced by bypass flow rates, eight ketamine anesthetized lambs (age range 1 to 8 days) had measurements of cerebral hemodynamics before and after institution of venoarterial bypass.

METHODS

Cerebral blood flow (whole brain and regional) were measured using the radiolabeled microsphere technique. A left carotid artery catheter (placed without sacrificing the vessel) reference sample was used for calculation of brain blood flows. Arterial and venous (sagittal sinus) oxygen contents and blood gases were measured across the cerebral circulation. Cerebral oxygen consumption, oxygen delivery, and fractional oxygen extraction were calculated. Measurements were made pre-ECMO and after placement on venoarterial ECMO at flow rates of 50 and 100 mL/kg/min. In addition, four other lambs were studied at a flow rate of 150 mL/kg/min, and seven additional animals were used to address methodologic issues with the microsphere technique in this model.

RESULTS

Cerebral blood flow and oxygen delivery significantly decreased, compared with control at both flow rates of 100 and 50 mL/kg/min (87.8 +/- 5.2 vs. 36.4 +/- 6.2; and 35.1 +/- 5.8 mL/100 g/min; 5.82 +/- 0.37 vs. 2.14 +/- 0.35; and 2.19 +/- 0.39 microM/100 g/min, respectively). Cerebral fractional oxygen extraction increased significantly at a flow of 50 mL/kg, and cerebral oxygen consumption decreased significantly at a flow of 100 mL/kg. At a flow rate of 150 mL/kg/min, cerebral hemodynamic variables did not differ from control measurements.

CONCLUSIONS

These findings demonstrate that changes in cerebral blood flow and cerebral oxygen metabolism can occur in the newborn lamb with the initiation of ECMO, and that these changes are dependent on bypass flow rate.

摘要

背景与目的

在接受体外膜肺氧合（ECMO）治疗的婴儿中，脑血流变化引起的神经损伤是一个令人关注的问题。为了研究脑血流动力学是否会受到旁路流速的影响，对八只氯胺酮麻醉的羔羊（年龄范围为1至8天）在建立静脉 - 动脉旁路前后进行了脑血流动力学测量。

方法

使用放射性微球技术测量脑血流量（全脑和局部）。左颈动脉导管（在不牺牲血管的情况下放置）参考样本用于计算脑血流量。测量整个脑循环中的动脉和静脉（矢状窦）氧含量及血气。计算脑氧消耗、氧输送和氧摄取分数。在ECMO前以及以50和100 mL/kg/min的流速置于静脉 - 动脉ECMO后进行测量。此外，对另外四只羔羊以150 mL/kg/min的流速进行了研究，并且使用另外七只动物来解决该模型中微球技术的方法学问题。

结果

与对照组相比，在100和50 mL/kg/min的流速下，脑血流量和氧输送均显著降低（分别为87.8±5.2对36.4±6.2；以及35.1±5.8 mL/100 g/min；5.82±0.37对2.14±0.35；以及2.19±0.39 microM/100 g/min）。在50 mL/kg的流速下，脑氧摄取分数显著增加，而在100 mL/kg的流速下，脑氧消耗显著降低。在150 mL/kg/min的流速下，脑血流动力学变量与对照测量值无差异。