脂肪乳剂救治布比卡因所致心脏骤停时肾上腺素合理使用时机探讨

Delayed injection of epinephrine is harmful in lipid-based resuscitation of bupivacaine-induced cardiac arrest in rats

目的探讨脂肪乳剂救治布比卡因所致心脏骤停时肾上腺素合理使用时机,并观察大鼠复苏效果。方法将20只雄性SD大鼠随机分为推注脂肪乳剂后给予肾上腺素组(ALE组)、推注脂肪乳剂后延迟1min给予肾上腺素组(DLE组),每组10只。大鼠股静脉推注布比卡因15mg/kg,心脏停搏后1min推注脂肪乳剂负荷量(5ml/kg),随后以1ml/(kg·min)速度持续输注5min。同时ALE组于心脏停搏后75s注射肾上腺素10μg/kg,135s注射0.9%氯化钠注射液0.1ml,DLE组在75s注射0.9%氯化钠注射液0.1ml,135s注射肾上腺素10μg/kg。如若自主循环未恢复则在4min后追加肾上腺素5μg/kg,随后每隔2min追加肾上腺素5μg/kg,直至自主循环恢复或者20min复苏期末。记录两组大鼠血流动力学指标及20min复苏末血气值、复苏率、存活率、肺湿干比、肺泡损伤率和布比卡因浓度等并作比较。结果 ALE组和DLE组存活率分别为100%和40%,差异有统计学意义(P<0.01)。复苏后ALE组SBP和RPP均高于DLE组(P<0.01)。ALE组心脏停搏后2min和20min的p H较DLE组高(P<0.05)。两组大鼠肺湿干比和肺泡损伤率差异均有统计学意义(均P<0.05)。心肌组织布比卡因浓度ALE组显著低于DLE组(P<0.05)。结论在布比卡因导致的心脏停搏模型中,注射脂肪乳剂后延迟注射肾上腺素不利于心脏早期复跳,降低复苏成功率。

Objective To investigate the effect of epinephrine given at different time points on lipid-based resuscitation for bupivacaine-induced cardiac arrest in rats.Methods Twenty adult male Sprague-Dawley rats were subjected to bupivacaine-induced asystole;after 30% intralipid was given 1 min after cardiac arrest the rats were randomly divided into 2 groups with 10 animals in each：epinephrine was given immediately （ALE group） or 1 min after the initial bolus of intralipid administration（DLE group）.Epinephrine was administered at regular intervals until return of spontaneous circulation （ROSC） or the end of a 20 minute-resuscitation period.Hemodynamic parameters were monitored,arterial blood gas was analyzed at 2 and 20 min after heart arrest,wet-to-dry lung weight ratio was calculated,and myocardial bupivacaine contents were measured.Results The survival rate of ALE group was significantly higher than that of DLE group （100% vs.40%,P=-0.005）.After ROSC,the rate pressure product （RPP） and systolic blood pressure （SBP） of group ALE were higher than those of DLE group （P〈0.05）.Wet-to-dry lung weight ratio of DLE group was higher than the ALE （P〈0.001）.The arterial blood pH of ALE group at 2 and 20 min after arrest was higher than that of DLE group （P〈0.05）.The rate of damaged alveoli in ALE group was lower than that of DLE group （P〈0.001）.The content of bupivacaine in cardiac tissue of ALE group was lower than that of DLE group （P=0.021）.Conclusion In rat model of bupivacaine-induced cardiac arrest,delayed injection of epinephrine is harmful,it would reduce the success rate of resuscitation with lipid emulsion.