RESUMO
PURPOSE: To assess the physiological and clinical effects of different rates of intravenous fluids for volume expansion of critically ill and perioperative patients. METHODS: We searched PubMed, EMBASE, and Cochrane Central Register of Controlled Trials for studies comparing intravenous infusion rates both in animals and studies involving healthy subjects, critically ill, and perioperative care patients of all ages. RESULTS: Seven animal studies, eleven clinical studies and three studies including healthy volunteers were identified. Slower infusion led to lower mortality in two studies, lower blood loss in one study, better or more sustained expansion of plasma volume and less edema in three studies, but slower restoration of blood pressure in one study. Three healthy volunteer studies suggested more effective plasma expansion with slower infusion, whereas one trial with postoperative patients did not show plasma volume differences between different infusion rates. One randomized trial found increased mortality with faster infusion in septic children, whereas a randomized trial found no significant differences in critically ill adults. CONCLUSIONS: In this scoping review, most studies showed that slower intravenous infusion rates result in a more efficient intravascular expansion, with a longer effect, and less edema than faster rates. Effects on clinical outcomes were inconsistent.