多沙普仑在常氧和低氧条件下对麻醉猪的代谢、通气和循环影响。

Metabolic, ventilatory and circulatory effects of doxapram in anaesthetized pigs during normoxia and hypoxia.

作者信息

Björk L, Arborelius M, Renck H, Rosberg B

机构信息

Department of Anaesthesiology, University Hospital MAS, Malmö, Sweden.

出版信息

Acta Anaesthesiol Scand. 1996 Sep;40(8 Pt 1):919-26. doi: 10.1111/j.1399-6576.1996.tb04561.x.

DOI:10.1111/j.1399-6576.1996.tb04561.x

PMID:8908229

Abstract

BACKGROUND

In a previous clinical study doxapram was found to improve ventilatory efficacy postoperatively, presumably via effects on hypoxic pulmonary vasoconstriction (HPV). The present study was designed to see whether doxapram induced any changes of arterial oxygenation and pulmonary vascular resistance during normoxia or hypoxia and whether the changes were influenced by the anaesthetic agents.

METHODS

Seventeen piglets were anaesthetized by combinations of either midazolam + fentanyl + pancuronium + pentobarbital (TIVA, n = 9), or by midazolam + fentanyl + pancuronium + halothane, 0.5% in end-tidal gas (Hal, n = 8). Analyses of expired gas and mixed venous and arterial blood in combination with determinations of central blood flow and pressures allowed for calculations of standard metabolic, ventilatory and circulatory data. Values were obtained at normoventilation using normoxic (FIO2 = 0.3) and hypoxic (FIO2 = 0.08) gas mixtures at calculated doxapram plasma concentrations of 1, 2 and 4 micrograms.ml-1.

RESULTS

With few exceptions doxapram administration affected the investigated variables only moderately during normoxia. In group Hal, PVR and SVR showed a biphasic raise (P < 0.05), CO fell (P < 0.05-P > or = 0.05) and C (a-v)O2 rose (P < 0.05). In group TIVA, PaO2 fell (P < 0.01-0.05) despite unchanged PVR, CO and VD/VT. Hypoxia affected a moderate increase in PVR in group TIVA (P < 0.05), which was slightly lower at the lowest and highest plasma levels of doxapram (P < 0.05). In group Hal, the induction of hypoxia induced a more pronounced rise in PVR (P < 0.05) which showed a biphasic response to increasing dose levels of doxapram, the lowest dose affecting a further rise (P < 0.05) and the highest a reduction to values below hypoxia control levels (P < 0.05). Pronounced differences between the two groups with respect to values for metabolic and circulatory variables make the interpretation of data difficult.

CONCLUSIONS

Doxapram administration to anaesthetized animals did not induce any effects indicative of augmentation of the HPV response.

摘要

背景

在之前的一项临床研究中，发现多沙普仑可改善术后通气效果，推测是通过对低氧性肺血管收缩（HPV）的作用。本研究旨在观察多沙普仑在常氧或低氧状态下是否会引起动脉氧合和肺血管阻力的变化，以及这些变化是否受麻醉药物影响。

方法

17只仔猪分别通过咪达唑仑+芬太尼+潘库溴铵+戊巴比妥（全凭静脉麻醉，n = 9）或咪达唑仑+芬太尼+潘库溴铵+0.5%呼气末浓度的氟烷（氟烷麻醉，n = 8）进行麻醉。通过分析呼出气体、混合静脉血和动脉血，并结合中心血流和压力测定，计算标准代谢、通气和循环数据。在常氧通气（FIO2 = 0.3）和低氧通气（FIO2 = 0.08）条件下，使用计算得出的多沙普仑血浆浓度为1、2和4微克/毫升时，获取相关数值。

结果

除少数情况外，多沙普仑给药在常氧状态下对所研究变量的影响较小。在氟烷麻醉组中，肺血管阻力（PVR）和体循环血管阻力（SVR）呈双相升高（P < 0.05），心输出量（CO）下降（P < 0.05 - P≥0.05），动静脉血氧含量差（C(a - v)O2）升高（P < 0.05）。在全凭静脉麻醉组中，尽管PVR、CO和VD/VT不变，但动脉血氧分压（PaO2）下降（P < 0.01 - 0.05）。低氧状态下，全凭静脉麻醉组的PVR有中度升高（P < 0.05），在多沙普仑血浆最低和最高水平时略低（P < 0.05）。在氟烷麻醉组中，低氧诱导使PVR有更明显的升高（P < 0.05），其对多沙普仑剂量增加呈双相反应，最低剂量使PVR进一步升高（P < 0.05），最高剂量使其降至低于低氧对照水平（P < 0.05）。两组在代谢和循环变量值方面存在明显差异，这使得数据解释困难。