Christian Loubert1, Pierre-Olivier Gagnon2, Roshan Fernando3. 1. Maisonneuve-Rosemont Hospital affiliated to the University of Montreal, 5415 boul. L'Assomption, Montreal, (QC), H1T 2M4, Canada. Electronic address: loubertch@yahoo.fr. 2. Maisonneuve-Rosemont Hospital affiliated to the University of Montreal, 5415 boul. L'Assomption, Montreal, (QC), H1T 2M4, Canada. Electronic address: pogagnon@gmail.com. 3. University College London Hospitals NHS Foundation Trust, 235 Euston Road, London, NW1 2BU, United Kingdom. Electronic address: roshanagfernando@gmail.com.
Abstract
STUDY OBJECTIVE: The aim of this study was to de termine the minimum effective fluid volume (MEFV) of hydroxyethyl starch 130/0.4 (HES) infused in a preload fashion which would prevent hypotension in 50% of parturients undergoing caesarean section. A secondary objective was to measure the hemodynamic effect of fluid loading on the subjects. DESIGN: This is a prospective, double-blinded, dose-finding study using an up-down sequential allocation design. SETTING: In the operating room. PATIENTS: Thirty healthy parturients undergoing caesarean section under spinal anesthesia using aprophylactic phenylephrine infusion were included in this study. INTERVENTION: The initial HES volume infused in the first patient was 500 mL. A failure of treatment to HES preload was defined as a single episode of systolic hypotension below 20% of baseline value. The next patient in the sequence was given a volume of HES adjusted by either an increment or a decrement of 100 mL according to the previous subject response to fluid preload. MEASUREMENTS: Stroke volume and cardiac output were measured with a bioreactance-based non-invasive cardiac output monitor (NICOM). MAIN RESULTS: The MEFV of HES was 733 mL (95% CI: 388-917 mL). Fluid loading before the administration of the spinal anesthesia resulted in an increase in stroke volume and cardiac output. The combined effect of spinal anesthesia and a phenylephrine infusion reduced the maternal heart rate and cardiac output, but not the stroke volume. CONCLUSION: Our study is the first to investigate variable fluid loading volumes in this population. A HES preload of approximatively 700 mL prevented maternal hypotension in 50% of the parturients under the conditions of this study. We suggest that up-down sequential allocation design is a useful tool to compare different fluid loading regimens in this setting.
RCT Entities:
STUDY OBJECTIVE: The aim of this study was to de termine the minimum effective fluid volume (MEFV) of hydroxyethyl starch 130/0.4 (HES) infused in a preload fashion which would prevent hypotension in 50% of parturients undergoing caesarean section. A secondary objective was to measure the hemodynamic effect of fluid loading on the subjects. DESIGN: This is a prospective, double-blinded, dose-finding study using an up-down sequential allocation design. SETTING: In the operating room. PATIENTS: Thirty healthy parturients undergoing caesarean section under spinal anesthesia using a prophylactic phenylephrine infusion were included in this study. INTERVENTION: The initial HES volume infused in the first patient was 500 mL. A failure of treatment to HES preload was defined as a single episode of systolic hypotension below 20% of baseline value. The next patient in the sequence was given a volume of HES adjusted by either an increment or a decrement of 100 mL according to the previous subject response to fluid preload. MEASUREMENTS: Stroke volume and cardiac output were measured with a bioreactance-based non-invasive cardiac output monitor (NICOM). MAIN RESULTS: The MEFV of HES was 733 mL (95% CI: 388-917 mL). Fluid loading before the administration of the spinal anesthesia resulted in an increase in stroke volume and cardiac output. The combined effect of spinal anesthesia and a phenylephrine infusion reduced the maternal heart rate and cardiac output, but not the stroke volume. CONCLUSION: Our study is the first to investigate variable fluid loading volumes in this population. A HES preload of approximatively 700 mL prevented maternal hypotension in 50% of the parturients under the conditions of this study. We suggest that up-down sequential allocation design is a useful tool to compare different fluid loading regimens in this setting.
Authors: Nur Dyana Md Nizar; Shamsul Kamalrujan Hassan; Rhendra Hardy Mohamad Zaini; Mohamad Hasyizan Hassan; Wan Mohd Nazaruddin Wan Hassan; Mohd Zulfakar Mazlan Journal: Malays J Med Sci Date: 2020-12-29