Paret G, Vaknin Z, Ezra D, Peleg E, Rosenthal T, Vardi A, Mayan H, Barzilay Z
Pediatric ICU, Chaim Sheba Medical Center, Tel Hashomer, Israel.
Resuscitation. 1997 Aug;35(1):77-82. doi: 10.1016/s0300-9572(96)01091-x.
to define the optimal volume of dilution for endotracheal(ET) administration of epinephrine (EPI).
prospective, randomized, laboratory comparison of four different volumes of dilution of endotracheal epinephrine (1, 2, 5, and 10 ml of normal saline).
large animal research facility of a university medical center.
epinephrine (0.02 mg/kg) diluted with four different volumes (1, 2, 5, and 10 ml) of normal saline was injected into the ET tube of five anesthetized dogs. Each dog served as its own control and received all four volumes in different sequences at least 1 week apart. Arterial blood samples for plasma epinephrine concentration and blood gases were collected before and 0.25, 0.5, 0.75, 1, 2, 3, 4, 5, 10, 15, 20, 25, 30 and 60 min after drug administration. Heart rate and arterial blood pressure were continuously monitored with a polygraph recorder.
higher volumes of diluent (5 and 10 ml) caused a significant decrease of PaO2, from 147 +/- 8 to 106 +/- 10 torr, compared with the lower volumes of diluent (1 and 2 ml), from 136 +/- 10 to 135 +/- 7 torr (P < 0.05). These effects persisted for over 30 min. Mean plasma epinephrine concentrations significantly increased within 15 s following administration for all the volumes of diluent. Mean plasma epinephrine concentrations, maximal epinephrine concentration (Cmax) and the coefficient of absorption (Ka) were higher in the 5 and 10 ml groups. The time interval to reach maximal concentration (Tmax) was shorter in the 5 and 10 ml groups. Yet these results were not significantly different. Heart rate, systolic and diastolic blood pressures did not differ significantly between the groups throughout the study.
Dilution of endotracheal epinephrine into a 5 ml volume with saline optimizes drug uptake and delivery without adversely affecting oxygenation and ventilation.
确定气管内给予肾上腺素（EPI）的最佳稀释体积。
对四种不同体积稀释的气管内肾上腺素（1、2、5和10毫升生理盐水）进行前瞻性、随机、实验室比较。
大学医学中心的大型动物研究设施。
将用四种不同体积（1、2、5和10毫升）生理盐水稀释的肾上腺素（0.02毫克/千克）注入五只麻醉犬的气管内导管。每只犬作为自身对照，以不同顺序接受所有四种体积的药物，间隔至少1周。在给药前以及给药后0.25、0.5、0.75、1、2、3、4、5、10、15、20、25、30和60分钟采集动脉血样本，检测血浆肾上腺素浓度和血气。用多导记录仪持续监测心率和动脉血压。
与较低体积稀释剂（1和2毫升）相比，较高体积稀释剂（5和10毫升）导致动脉血氧分压（PaO₂）显著降低，从147±8降至106±10托，而较低体积稀释剂组从136±10降至135±7托（P<0.05）。这些影响持续超过30分钟。所有体积稀释剂给药后15秒内，平均血浆肾上腺素浓度均显著升高。5毫升和10毫升组的平均血浆肾上腺素浓度、最大肾上腺素浓度（Cmax）和吸收系数（Ka）更高。5毫升和10毫升组达到最大浓度的时间间隔（Tmax）更短。然而，这些结果并无显著差异。在整个研究过程中，各组之间的心率、收缩压和舒张压无显著差异。
将气管内肾上腺素用5毫升生理盐水稀释可优化药物吸收和输送，且不会对氧合和通气产生不利影响。
