Desparmet J F, Berde C B, Schwartz D C, Lunn R J, Hershenson M B
Department of Anesthesia, Children's Hospital, Harvard Medical School, Boston, MA 02115.
Eur J Anaesthesiol. 1991 Mar;8(2):123-8.
It has been shown that an epidural test dose with adrenaline does not always detect an intravascular injection in halothane-anaesthetized children. To ascertain whether test dosing with other agents might be more useful, we sought to determine if and at what dose levels three different intravenous drugs (adrenaline, isoprenaline and 1% lignocaine with 1/200,000 adrenaline) produced an increase in heart rate (HR) in halothane-anaesthetized lambs. Eight 2-week-old lambs were anaesthetized with 1% halothane in oxygen. The lambs were intubated and ventilated in order to maintain end-tidal and arterial CO2 within normal limits; HR and blood pressure before and 15-180 s after the injection of four increasing doses of each drug were recorded. The same set of measurements was repeated after the intravenous injection of atropine 10 micrograms kg-1. Adrenaline-containing doses produced a more sustained increase in HR (P less than 0.05, ANOVA) at lower doses of adrenaline when atropine was injected first. This increase did not occur in all lambs, and dysrhythmias were manifest in some. Isoprenaline always produced a significant increase in HR without dysrhythmias whether atropine was given or not. We conclude that in halothane-anaesthetized lambs, isoprenaline is a more reliable indicator of intravascular injection than adrenaline.
已有研究表明，在氟烷麻醉的儿童中，使用含肾上腺素的硬膜外试验剂量并不总能检测到血管内注射情况。为确定使用其他药物进行试验剂量是否可能更有用，我们试图确定三种不同的静脉药物（肾上腺素、异丙肾上腺素和含1/200,000肾上腺素的1%利多卡因）在氟烷麻醉的羔羊中是否以及在何种剂量水平下会导致心率（HR）增加。八只2周龄的羔羊用1%氟烷在氧气中麻醉。羔羊进行气管插管并通气，以维持呼气末和动脉二氧化碳在正常范围内；记录每种药物四个递增剂量注射前及注射后15 - 180秒的心率和血压。在静脉注射10微克/千克阿托品后重复进行相同的一组测量。当首先注射阿托品时，含肾上腺素的剂量在较低剂量的肾上腺素时会使心率产生更持续的增加（方差分析，P小于0.05）。这种增加并非在所有羔羊中都出现，并且在一些羔羊中出现了心律失常。无论是否给予阿托品，异丙肾上腺素总是会使心率显著增加且无心律失常。我们得出结论，在氟烷麻醉的羔羊中，异丙肾上腺素比肾上腺素是血管内注射更可靠的指标。
