Impact of the fluid challenge infusion rate on cardiac stroke volume during major spinal neurosurgery: a prospective single center randomized interventional trial

Abstract

Background: Fluid therapy, including the choice of a crystalloid or colloid infusion, the execution time of a volume bolus, and the expected volume need of a patient during surgery, varies greatly in clinical practice. Different goal directed fluid protocols have been developed, where fluid boluses guided by dynamic preload parameters are administered within a specific period. Objective: To study the efficacy of two fluid bolus infusion rates measured by the response of hemodynamic parameters. Design: Monocentric randomized controlled interventional trial. Setting: University hospital. Patients: Forty patients undergoing elective major spinal neurosurgery in prone position were enrolled, thirty-one were finally analyzed. Interventions: Patients were randomly assigned to receive 250 ml crystalloid and colloid boluses within 5 min (group 1) or 20 min (group 2) when pulse pressure variation (PPV) exceeded 14%. Main outcome measures: Changes in stroke volume (SV), mean arterial pressure (MAP), and catecholamine administration. Results: Group 1 showed a greater increase in SV (P = 0.031), and MAP (P = 0.014), while group 2 still had higher PPV (P = 0.005), and more often required higher dosages of noradrenalin after fluid administration (P = 0.033). In group 1, fluid boluses improved CI (P < 0.01), SV (P < 0.01), and MAP (P < 0.01), irrespective of whether crystalloids or colloids were used. In group 2, CI and SV did not change, while MAP was slightly increased (P = 0.011) only after colloid infusion.