Intravascular volume status and stress markers in patients observing long and short duration of fasting: A prospective single blinded observational study

Preoperative fasting may lead to intravascular volume depletion and this volume depletion may be a cause of perioperative stress. This study intends to compare the levels of stress markers in patients undergoing long and short duration fasting before an elective laparoscopic surgery.This was a single blind, observational study. Based on the duration of fasting, 70 ASA I and II category patients undergoing elective laparoscopic cholecystectomy(LC) were divided into two groups of 35 patients each. If the surgeon had prescribed a fasting since midnight then patient was considered for inclusion in Long fasting (LF) group; if surgeon had allowed clear fluids till 2 h before surgery then the patient was considered for inclusion in the short fasting(SF) group. The extent of intravascular volume depletion was measured using inferior vena cava collapsibility index (IVCCI). Levels of relevant stress markers i.e. cortisol, Tetraiodothyronine (FT4), C-peptide, C-reactive protein(CRP) and blood glucose (BGL) were measured at 8 PM in the night before surgery, at 7 AM on the day of surgery, 2 h after the surgery and 24 h after the surgery.IVCCI was significantly more in the LF group; 27.66 ± 3.34% vs17.83 ± 2.22%, 95% CI 8.47-11.18, P-value <0.001). IVCCI had a significant correlation with the duration of fasting, Pearson's correlation r = 0.69,P-value <0.001. Repeated measures ANCOVA revealed that CRP, Free T4 and C-peptide levels got significantly elevated over the study duration, P-values <0.001,<0.001 and 0.03 respectively but with IVCCI, Age and Gender as the covariates, the increase in the levels of CRP, Free T4 and C-peptide were similar in both the groups.Stress markers levels show significant elevation in the perioperative period, maximum over the study duration, but this change is similar in both the groups.CTRI/2021/02/031456.