允许性高碳酸血症在成人呼吸窘迫综合征管理中的心肺效应

Cardiopulmonary effects of permissive hypercapnia in the management of adult respiratory distress syndrome.

作者信息

McIntyre R C, Haenel J B, Moore F A, Read R R, Burch J M, Moore E E

机构信息

Department of Surgery, Denver General Hospital, Colorado 80204-4507.

出版信息

J Trauma. 1994 Sep;37(3):433-8. doi: 10.1097/00005373-199409000-00017.

DOI:10.1097/00005373-199409000-00017

PMID:8083905

Abstract

BACKGROUND

Despite numerous advances, the mortality from adult respiratory distress syndrome (ARDS) remains high. Traditional ventilator management in ARDS has been to maintain normal PaCO2 by positive pressure ventilation (PPV). However, high levels of PPV may worsen the lung injury by alveolar overdistension. Permissive hypercapnia (PHC) has been proposed as an alternative method of ventilation, but hypercapnia may affect the hemodynamics of a hyperdynamic, critically ill patient. The purpose of this study was to determine the effect of PHC on ventilator requirement, arterial oxygenation, and hemodynamic performance in patients with severe ARDS.

METHODS

Ten men and 5 women with established ARDS (mean Murray lung injury score 3.42 +/- 0.1) were prospectively studied using an established protocol when the static pulmonary plateau pressure (Pplat) exceeded 40 cm H2O. The initial tidal volume (V(t)) was decreased to achieve a Pplat < 40 cm H2O or to a lower limit of 5 cc/kg. Arterial blood gas and hemodynamic data were obtained serially.

RESULTS

The V(t) was reduced from 9.9 +/- 0.5 mL/kg to 7.7 +/- 0.5 mL/kg at 24 hours, p < 0.05. This reduction of V(t) produced a decrease in minute ventilation (Ve: 18.0 +/- 1.6 to 11.9 +/- 0.7 L/min, p < 0.05), peak airway pressure (PAP: 55 +/- 2 vs 45 +/- 3 cm H2O, p < 0.05), and Pplat (Pplat 45.4 +/- 1.5 vs. 36.7 +/- 1.9) at 24 hours. The PaCO2 rose from 37.9 +/- 1.3 to 56.7 +/- 3.0 mm Hg (p < 0.05), and the pH decreased from 7.41 +/- 0 to 7.31 +/- 0 (p < 0.05) at 24 hours. There were no significant changes in mean airway pressure, static compliance, arterial oxygenation, pulmonary vascular resistance, systemic vascular resistance, cardiac index, or systemic oxygen delivery and consumption.

CONCLUSIONS

Permissive hypercapnia by V(t) reduction: (1) decreased Ve, PAP, and Pplat without a change in mean airway pressure, static compliance or arterial oxygenation; (2) caused a mild partially compensated acidosis; and (3) does not adversely affect pulmonary vascular resistance, systemic vascular resistance, cardiac index, or systemic oxygen delivery and consumption.

摘要

背景

尽管取得了诸多进展，但成人呼吸窘迫综合征（ARDS）的死亡率仍然很高。ARDS传统的通气管理方法是通过正压通气（PPV）维持正常的动脉血二氧化碳分压（PaCO₂）。然而，高水平的PPV可能因肺泡过度扩张而加重肺损伤。允许性高碳酸血症（PHC）已被提出作为一种替代通气方法，但高碳酸血症可能会影响高动力危重症患者的血流动力学。本研究的目的是确定PHC对重症ARDS患者通气需求、动脉氧合和血流动力学表现的影响。

方法

对10名男性和5名女性确诊为ARDS的患者（平均默里肺损伤评分3.42±0.1）进行前瞻性研究，研究方案为当静态肺平台压（Pplat）超过40 cmH₂O时，初始潮气量（V(t)）降低以实现Pplat＜40 cmH₂O或降至5 cc/kg的下限。连续获取动脉血气和血流动力学数据。

结果

24小时时V(t)从9.9±0.5 mL/kg降至7.7±0.5 mL/kg，p＜0.05。V(t)的降低导致分钟通气量（Ve：18.0±1.6降至11.9±0.7 L/min，p＜0.05）、气道峰压（PAP：55±2 vs 45±3 cmH₂O，p＜0.05）和24小时时的Pplat（Pplat 45.4±1.5 vs. 36.7±1.9）下降。24小时时PaCO₂从37.9±1.3升至56.7±3.0 mmHg（p＜0.05），pH从7.41±0降至7.31±0（p＜0.05）。平均气道压、静态顺应性、动脉氧合、肺血管阻力、体循环血管阻力、心脏指数或体循环氧输送和消耗均无显著变化。