Prevention of arterial hypotension after spinal anaesthesia using vena cava ultrasound to guide fluid management.

BACKGROUND: Significant hypotension is frequent after spinal anaesthesia and fluid administration as therapy is usually empirical. Inferior vena cava (IVC) ultrasound (US) is effective to assess fluid responsiveness in critical care patients. The aim of this study was to evaluate the IVCUS-guided volume optimization to prevent post-spinal hypotension. METHODS: In this prospective, randomized, cohort study, 160 patients scheduled for surgery under spinal anaesthesia were randomized into a study group (IVCUS-group), consisting of an IVCUS analysis before spinal anaesthesia with IVCUS-guided volume management and a control group (group C) with no IVCUS assessment. The primary outcome was a relative risk reduction in the incidence of hypotension between the groups; secondary outcomes were the need for vasoactive drugs and the amounts of fluids required after spinal anaesthesia. We also tested the hypothesis of a correlation between IVC collapsibility index and hypotension after spinal anaesthesia. RESULTS: The relative risk reduction of hypotension between the groups was 35% (IVCUS-group 27.5%, Group C 42.5%, P=0.044, CI=95%). The need for vasoactive drugs in the IVCUS-group was significantly lower compared to the C-group (P=0.015), while the total amount of fluids was significantly superior higher in the IVCUS group (P<0.0001) compared to Group C. IVC collapsibility index was correlated with the amount of fluid administered (r2=0.32), but could not be used to predict postspinal anaesthesia hypotension. CONCLUSIONS: IVCUS is an effective method to prevent postspinal anaesthesia hypotension by IVCUS-guided fluid administration before spinal anaesthesia. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov - NCT02271477.

PROtocolized care to reduce HYpotension after spinal anaesthesia (ProCRHYSA randomized trial): Study protocol for a randomized controlled trial.

BACKGROUND: The PROtocolized Care to Reduce HYpotension after Spinal Anaesthesia (ProCRHYSA trial) is an unblinded, randomized, monocentric, prospective, three-arm, parallel-group trial aimed at assessing the role of a controlled volemic repletion in reducing both clinically significant hypotension rate and total amount of fluid administered in patients undergoing spinal anaesthesia. METHODS/DESIGN: Aim of the study is assessing the effectiveness of a non-invasive tests to guide a titrated volemic repletion before spinal anesthesia in order to reduce post-spinal hypotension rate. After local ethical committee approval of the study (Comitato Etico Cantonale Ref. N. CE2796), we will randomize patients undergoing elective surgery under spinal anesthesia into two parallel groups: in the first vena cava ultrasound will be used in order to assess adequacy of patients' volemic status and consequently guide the administration of crystalloids boluses; in the second passive legs raising test will be used instead of ultrasound for the same purpose. DISCUSSION: The hypothesis we want to test is that the using of these two experimental methods before spinal anaesthesia, compared to the standard method (empirical fluid administration) can reduce the impact of systemic hypotension through an adequate titrated volemic repletion, avoiding both hypotension and fluid overload. The final purpose is to ensure that spinal anaesthesia is performed in the safest way possible. CONCLUSIONS: The study will offer a new insight on the possible role of vena cava ultrasound and passive legs raising test as screening tools to prevent hypotension after spinal anesthesia. These tests were already validated in a critical environment, but to the best of our knowledge this is the first time they are applied to an elective surgical population. TRIAL REGISTRATION: The trial was registered on May 2014 on www.clinicalstrial.gov with the number NCT02070276.