Fluid management in non-pregnant people with SCD

• Although helpful to overcome dehydration, intravenous (IV) hydration often leads to adverse outcomes such as fluid overload, pulmonary oedema, increased length of stay, transfer to intensive care unit, and new oxygen requirement (161). Small-scale retrospective studies have failed to conclusively demonstrate its benefits as well as choice of IV fluids, and rate of IV fluid replacement (161).
• A retrospective chart review of volume overload in SCD found no difference in incidence of volume overload for patients treated with 0.9% saline versus 0.65% saline (162). The association with volume of IV fluids given could not be assessed.
• Another chart review study comparing use of normal saline bolus with no bolus suggested that the use of normal saline bolus is associated with poorer pain control in children with SCD and vaso-occlusive pain (163).
• In vitro studies suggest that normal saline may worsen sickling compared to hypotonic solutions (164, 165). Fluid management in pregnancy
• Uteroplacental circulation is reliant on maternal cardiac output, blood pressure and metabolic homeostasis to function correctly and avoid fetal compromise. In addition, the pregnant woman undergoes a number of physiological adaptations that affect fluid management, including an increase in the circulating volume and a reduction in systemic vascular resistance (166).
• There is considerable evidence that volume overload and persistently positive fluid balance are associated with poorer outcomes in non-obstetric intensive care unit admissions (166).
• Due to the factors outlined above, there is a need to carefully calibrate and readjust the rate of IV fluid hydration, guided by clinical assessment. Both rate and volume of fluid administration need to be balanced with the risks associated with administration of IV fluids. Choice of fluids
• There is limited evidence to guide the choice of fluids in the general pregnant population. In the critically ill pregnant patient, isotonic crystalloids represent a safe initial choice in a wide variety of maternal conditions (166). Other synthetic colloids and starches may be associated with significant risks (166).
• The choice of fluid will be influenced primarily by the prescribing clinician’s experience with that particular fluid, its cost and local availability. Fluid choices may include isotonic fluids such as normal saline solution, 5% dextrose in water, lactated Ringer’s solution 5% dextrose in water. There is no evidence on the use of hypotonic fluids such as 0.45% saline, 0.25% saline for the management of vaso-occlusive crises in pregnant women with SCD. Areas for further research
• There is a lack of RCTs and a need for large multicentre trials to assess the best route, quantity and type of fluid replacement for people with SCD with acute painful crises (167).