Horton J W, White D J, Hunt J L
Department of Surgery, University of Texas Southwestern Medical Center, Dallas.
J Trauma. 1995 Feb;38(2):281-6. doi: 10.1097/00005373-199502000-00027.
Experimental studies in our laboratory showed that hypertonic saline dextran (HSD; 7.5 NaCl in 6% dextran 70) given as a small bolus (4 mL/kg) immediately after burn injury in guinea pigs improved cardiac contractile performance and reduced the total fluids requirements. Although these data confirm the cardioprotective effects of HSD given immediately postburn, prehospital and early inhospital management of severely burned patients consists of aggressive crystalloid fluid resuscitation to correct intravascular volume deficits. The question arose as to whether delaying HSD for several hours after initiating crystalloid resuscitation would provide cardioprotection.
Third-degree scald burns comprising 45 +/- 1% of the total body surface area (burn groups, n = 40) or 0% for controls (group 1, n = 12) were produced; in groups 2 to 5, lactated Ringer's (LR) resuscitation was initiated immediately postburn according to the Parkland formula, 4 mL/kg/% burn. In group 2, (n = 12), LR was continued for 24 hours. HSD was administered as an i.v. bolus at either 1 hour (group 3, n = 10), 4 hours (group 4, n = 9), or 8 hours postburn (group 5, n = 9); immediately after HSD administration, LR was continued (1 mL/kg/% burn) until 24 hours postburn.
Compared to sham burn controls, hearts from burned animals treated with LR alone had significant cardiac dysfunction, as indicated by a lower left ventricular pressure and +/- dP/dt. Compared with hearts from LR-treated animals, hearts from burned animals treated with HSD 1 hour (HSD-1) and 4 hours (HSD-4) after burn injury had significantly higher LVP and +/- dP/dt. Ventricular function curves calculated for HSD-1 and HSD-4 groups were comparable to those calculated for hearts from sham burns. Delaying HSD administration until 8 hours after burn provided little cardioprotection.
Our data indicate that HSD effectively maintains cardiac function and reduces overall total fluid requirements if administered within 4 hours after burn injury.
我们实验室的实验研究表明，在豚鼠烧伤后立即给予小剂量推注（4毫升/千克）的高渗盐水右旋糖酐（HSD；7.5%氯化钠加6%右旋糖酐70）可改善心脏收缩功能并减少总液体需求量。尽管这些数据证实了烧伤后立即给予HSD的心脏保护作用，但严重烧伤患者的院前和早期院内处理包括积极的晶体液复苏以纠正血管内容量不足。于是产生了一个问题，即在开始晶体液复苏数小时后延迟给予HSD是否能提供心脏保护。
造成占总体表面积45±1%的三度烫伤（烧伤组，n = 40），对照组为0%（第1组，n = 12）；在第2至5组中，烧伤后立即根据帕克兰公式（4毫升/千克/%烧伤）开始乳酸林格氏液（LR）复苏。在第2组（n = 12）中，LR持续24小时。在烧伤后1小时（第3组，n = 10）、4小时（第4组，n = 9）或8小时（第5组，n = 9）静脉推注给予HSD；在给予HSD后立即继续给予LR（1毫升/千克/%烧伤）直至烧伤后24小时。
与假烧伤对照组相比，仅接受LR治疗的烧伤动物的心脏存在明显的心功能障碍，表现为左心室压力及±dP/dt较低。与接受LR治疗的动物的心脏相比，烧伤后1小时（HSD - 1）和4小时（HSD - 4）接受HSD治疗的烧伤动物的心脏具有明显更高的左心室压力及±dP/dt。为HSD - 1组和HSD - 4组计算的心室功能曲线与为假烧伤心脏计算的曲线相当。将HSD给药延迟至烧伤后8小时几乎不能提供心脏保护。
我们的数据表明，如果在烧伤后4小时内给予HSD，其可有效维持心脏功能并减少总体液体需求量。
