Different effects of fluid loading with saline, gelatine, hydroxyethyl starch or albumin solutions on acid-base status in the critically ill

IntroductionFluid administration in critically ill patients may affect acid-base balance. However, the effect of the fluid type used for resuscitation on acid-base balance remains controversial.MethodsWe studied the effect of fluid resuscitation of normal saline and the colloids gelatine 4%, hydroxyethyl starch (HES) 6%, and albumin 5% on acid-base balance in 115 clinically hypovolemic critically ill patients during a 90 minute filling pressure-guided fluid challenge by a post-hoc analysis of a prospective randomized clinical trial.ResultsAbout 1700 mL was infused per patient in the saline and 1500 mL in each of the colloid groups (PConclusionIn clinically hypovolemic, critically ill patients, fluid resuscitation by only 1500–1700 mL of normal saline, gelatine, HES or albumin, resulted in a small decrease in pH, irrespective of the type of fluid used. Therefore, a progressive metabolic acidosis, even with increased anion gap, should not be erroneously attributed to insufficient fluid resuscitation.Trial registrationISRCTN Registry ISRCTN19023197**引言** 重症患者的液体治疗可影响酸碱平衡。然而，复苏所用液体类型对酸碱平衡的影响仍存在争议。 **方法** 本研究通过对一项前瞻性随机对照临床试验的事后分析，纳入115例临床确诊低血容量的重症患者，在90分钟充盈压指导下的液体负荷试验中，探讨生理盐水（normal saline）、4%明胶（gelatine）、6%羟乙基淀粉（HES）及5%白蛋白（albumin）四种复苏液体对酸碱平衡的影响。 **结果** 生理盐水组患者人均输注液体约1700 mL，各胶体液组人均输注量均为1500 mL（P **结论** 对于临床确诊低血容量的重症患者，仅输注1500~1700 mL生理盐水、明胶、HES或白蛋白实施液体复苏，无论选用何种液体类型，均会导致pH值小幅下降。因此，渐进性代谢性酸中毒（即便伴随阴离子间隙升高）不应被错误归因于液体复苏不足。 **试验注册** 本研究在ISRCTN注册中心注册，注册号为ISRCTN19023197。