Berkowitz I D, Gervais H, Schleien C L, Koehler R C, Dean J M, Traystman R J
Department of Anesthesiology/Critical Care Medicine, Johns Hopkins Hospital, Baltimore, Maryland 21205.
Anesthesiology. 1991 Dec;75(6):1041-50. doi: 10.1097/00000542-199112000-00017.
Although epinephrine increases cerebral blood flow (CBF) and left ventricular blood flow (LVBF) during cardiopulmonary resuscitation (CPR), the effects of high dosages on LVBF and CBF and cerebral O2 uptake have not been examined during prolonged CPR. We determined whether log increment dosages of epinephrine would enhance LVBF and CBF and cerebral O2 uptake in an infant swine CPR model. We compared these responses with epinephrine to those with the alpha-adrenergic agonist, phenylephrine. CPR was performed in five groups (n = 6) of pentobarbital-anesthetized piglets (3.5-5.6 kg) receiving a continuous epinephrine infusion (0, 1, 10, and 100 micrograms.kg-1.min-1) or phenylephrine infusion (40 micrograms.kg-1.min-1). Plasma epinephrine concentrations increased 10-100-fold in the control group during CPR and in a stepwise manner such that concentrations were increased by more than 10(4) in the 100 micrograms.kg-1.min-1 epinephrine group. In the control group with no epinephrine infusion, LVBF decreased to less than 10 ml.min-1.100 g-1 by 5 min of CPR. With epinephrine in dosages of 10 and 100 micrograms.kg-1.min-1, LVBF at 5 min was 75 +/- 19 and 44 +/- 15 ml.min-1.100 g-1, respectively, which was significantly greater than values in the control group. With more prolonged CPR, LVBF remained significantly greater than that in the control group but only at 10 micrograms.kg-1.min-1 of epinephrine. Phenylephrine also increased LVBF for 10 min of CPR when compared with the control group. All dosages of epinephrine and phenylephrine maintained CBF close to prearrest values for 20 min of CPR. With prolonged CPR, 10 and 100 micrograms.kg-1.min-1 epinephrine resulted in significantly greater CBF than that in the control group. Incremental dosages of epinephrine did not statistically increase cerebral O2 uptake or lower the cerebral fractional O2 extraction when compared with the control group, despite the higher CBF that was generated. In this immature animal CPR model, 10 micrograms.kg-1.min-1 epinephrine is an optimal dosage for maximizing both CBF and LVBF, a dosage that substantially exceeds the current recommended epinephrine dosage for human infant CPR. In addition, for short periods of CPR, 40 micrograms.kg-1.min-1 phenylephrine increases CBF and LVBF to levels similar to those generated by high dosages of epinephrine.
虽然肾上腺素在心肺复苏（CPR）期间可增加脑血流量（CBF）和左心室血流量（LVBF），但在长时间CPR期间高剂量肾上腺素对LVBF、CBF及脑氧摄取的影响尚未得到研究。我们在幼猪CPR模型中确定肾上腺素的对数递增剂量是否会增强LVBF、CBF及脑氧摄取。我们将这些肾上腺素反应与α-肾上腺素能激动剂去氧肾上腺素的反应进行了比较。对五组（n = 6）戊巴比妥麻醉的仔猪（3.5 - 5.6 kg）进行CPR，这些仔猪接受持续的肾上腺素输注（0、1、10和100微克·kg⁻¹·min⁻¹）或去氧肾上腺素输注（40微克·kg⁻¹·min⁻¹）。在CPR期间，对照组血浆肾上腺素浓度增加了10 - 100倍，且呈逐步增加，使得在100微克·kg⁻¹·min⁻¹肾上腺素组中浓度增加超过10⁴倍。在未输注肾上腺素的对照组中，CPR 5分钟时LVBF降至低于10 ml·min⁻¹·100 g⁻¹。使用10和100微克·kg⁻¹·min⁻¹剂量的肾上腺素时，5分钟时LVBF分别为75 ± 19和44 ± 15 ml·min⁻¹·100 g⁻¹，显著高于对照组的值。随着CPR时间延长，LVBF仍显著高于对照组，但仅在肾上腺素剂量为10微克·kg⁻¹·min⁻¹时如此。与对照组相比，去氧肾上腺素在CPR 10分钟时也增加了LVBF。所有剂量肾上腺素和去氧肾上腺素在CPR 20分钟内均使CBF维持在接近心跳骤停前的值。随着CPR时间延长，10和100微克·kg⁻¹·min⁻¹肾上腺素导致的CBF显著高于对照组。与对照组相比，尽管产生了较高的CBF，但肾上腺素递增剂量在统计学上并未增加脑氧摄取或降低脑氧分数提取率。在这个未成熟动物CPR模型中，10微克·kg⁻¹·min⁻¹肾上腺素是使CBF和LVBF最大化的最佳剂量，该剂量大大超过了目前推荐用于人类婴儿CPR的肾上腺素剂量。此外，在短时间CPR中，40微克·kg⁻¹·min⁻¹去氧肾上腺素可使CBF和LVBF增加至与高剂量肾上腺素产生的水平相似。
