新生儿局部低流量灌注期间的组织氧张力

Tissue oxygen tension during regional low-flow perfusion in neonates.

作者信息

DeCampli William M, Schears Gregory, Myung Richard, Schultz Steven, Creed Jennifer, Pastuszko Anna, Wilson David F

机构信息

Divisions of Pediatric Cardiothoracic Surgery and Anesthesia and Critical Care Medicine, The Children's Hospital of Philadelphia, Pa 19104, USA.

出版信息

J Thorac Cardiovasc Surg. 2003 Mar;125(3):472-80. doi: 10.1067/mtc.2003.13.

DOI:10.1067/mtc.2003.13

PMID:12658188

Abstract

OBJECTIVE

We examined cerebral cortical and peripheral organ tissue Po(2) values in a neonatal piglet model of regional low-flow perfusion.

METHODS

Twenty-one neonatal piglets were placed on cardiopulmonary bypass, were cooled to 18 degrees C, then underwent either deep hypothermic circulatory arrest or regional low-flow perfusion at 20 or 40 mL/(kg x min) for 90 minutes. Regional low-flow perfusion was carried out by advancing the aortic cannula into the proximal innominate artery. Tissue mean Po(2) and Po(2) distribution were measured in the cerebral cortex, liver, small bowel, and skeletal muscle through the principle of oxygen-dependent quenching of phosphorescence. Measured quantities were compared by analysis of variance or the Fisher exact test.

RESULTS

During regional low-flow perfusion, axillary and femoral arterial pressures, respectively, were 55 +/- 15 and 8 +/- 4 mm Hg at 40 mL/(kg x min) and 37 +/- 10 mm Hg (P =.04) and 17 +/- 5 mm Hg (P =.08) at 20 mL/(kg x min). Venous saturations were 95% +/- 6% at 40 mL/(kg x min) and 84% +/- 6% at 20 mL/(kg x min) (P =.03 at 15, 30, and 45 minutes). Cortical Po(2) was similar to prebypass values during regional low-flow perfusion at 40 mL/(kg x min) (53 +/- 5 mm Hg) but declined during reperfusion and recovery. Cortical Po(2) was lower than before bypass during low-flow perfusion at 20 mL/(kg x min) (38 +/- 7 mm Hg) but increased during reperfusion. Po(2) in liver and bowel was less than 10 mm Hg during low-flow perfusion at both 20 and 40 mL/(kg x min). Fraction of oxygen distribution with Po(2) lower than 15 mm Hg was less during perfusion at 40 mL/(kg x min) than at 20 mL/(kg x min) (P =.001). Three of 6 piglets that received a 40-mL/(kg x min) flow rate had significant upper torso edema, metabolic acidosis, and an unstable recovery period, whereas zero of 6 piglets that received a 20-mL/(kg x min) flow rate did.

CONCLUSIONS

In a piglet model, regional low-flow perfusion at 20 mL/(kg x min) resulted in lower cortical tissue oxygenation but better recovery than did perfusion at 40 mL/(kg x min). Neither flow rate adequately oxygenated organs in the lower torso.

摘要

目的

我们在区域低流量灌注的新生仔猪模型中检测了大脑皮质和外周器官组织的氧分压（Po₂）值。

方法

21只新生仔猪接受体外循环，冷却至18℃，然后进行深低温停循环或分别以20或40 mL/(kg×min)的流量进行区域低流量灌注90分钟。通过将主动脉插管推进至无名动脉近端来进行区域低流量灌注。通过磷光氧依赖性猝灭原理测量大脑皮质、肝脏、小肠和骨骼肌中的组织平均Po₂和Po₂分布。通过方差分析或Fisher精确检验比较测量值。

结果

在区域低流量灌注期间，40 mL/(kg×min)时腋窝和股动脉压分别为55±15和8±4 mmHg，20 mL/(kg×min)时分别为37±10 mmHg（P = 0.04）和17±5 mmHg（P = 0.08）。静脉血氧饱和度在40 mL/(kg×min)时为95%±6%，在20 mL/(kg×min)时为84%±6%（在15、30和45分钟时P = 0.03）。在以40 mL/(kg×min)进行区域低流量灌注期间，皮质Po₂与体外循环前的值相似（53±5 mmHg），但在再灌注和恢复期间下降。在以20 mL/(kg×min)进行低流量灌注期间，皮质Po₂低于体外循环前（38±7 mmHg），但在再灌注期间升高。在20和40 mL/(kg×min)的低流量灌注期间，肝脏和肠道中的Po₂均低于10 mmHg。Po₂低于15 mmHg时的氧分布分数在40 mL/(kg×min)灌注时低于20 mL/(kg×min)灌注时（P = 0.001）。接受40 mL/(kg×min)流量的6只仔猪中有3只出现明显的上半身水肿、代谢性酸中毒和恢复期不稳定，而接受20 mL/(kg×min)流量的6只仔猪中无一出现上述情况。