Comparing the Effects of Pre-loading with Gelatine 4% Plasma Volume Expander and 6% Hydroxyethyl Starch Solution Before Spinal Anaesthesia for Lower Limb Orthopaedic Surgery

BACKGROUND: Hypotension is a common complication following spinal anaesthesia. The administration of intravenous fluids prior to spinal anaesthesia, known as pre-loading, has been used to offset the hypotension effect; however, the ideal fluid for pre-loading is still a matter of debate. The objective of this study was to compare the effects of Gelaspan 4% and Volulyte 6% as pre-loading fluids.

METHODS: A total of 93 patients with American Society of Anaesthesiologists (ASA) physical status I or II having lower limb orthopaedic surgery under spinal anaesthesia were randomised into two groups that received either Volulyte (n = 47) or Gelaspan (n = 46). Before the spinal anaesthesia, these patients were pre-loaded with 500 mL of the fluid of their respective group. Blood samples were taken before pre-loading and again after spinal anaesthesia and sent for venous blood gas and electrolyte level measurement. Baseline and intraoperative records of systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR) and the requirement of ephedrine to treat hypotension were also recorded.

RESULTS: Both fluids could not prevent significant reductions in SBP (P = 0.011), DBP (P = 0.002) and MAP (P = 0.001). There was also significant reduction in HR over time (P < 0.001). There was no significant difference in terms of ephedrine usage between both groups. Neither Volulyte 6% nor Gelaspan 4% caused significant changes in acid-base status.

CONCLUSION: The use of 500 mL of either Gelaspan 4% or Volulyte 6% as pre-loading fluids did not significantly prevent the incidence of post-spinal anaesthesia hypotension following orthopaedic lower limb surgery; however, both were useful in the maintenance normal acid-base balance.