The Effect of Normal Saline and Plasmalyte on Acid–Base Status in Patients Undergoing Head-and-Neck Surgery with Free Flap Reconstruction: A Prospective, Observational Cohort Study

BACKGROUND: Intraoperative fluid strategy may affect the graft viability in head-and-neck surgeries with free flap reconstruction (HNS-FFR). Studies to guide regarding association of intraoperative fluid with metabolic parameters during such surgeries are infrequent. AIM: This study aimed to compare plasmalyte (PL) and normal saline (NS) (0.9%) in terms of acid–base balance and electrolytes in the peri-operative period along with graft viability during above-mentioned surgeries. SETTINGS AND DESIGN: Prospective, observational cohort study was conducted in patients, 18–65 years, undergoing HNS-FFR at a tertiary care center. MATERIALS AND METHODS: The cohort was categorized into two groups based on the intraoperative fluid used, i.e., PL (Group A) and NS (Group B) group. The primary objective was to compare arterial blood gas parameters at seven time points till the 3(rd) postoperative day. We studied the effect on graft viability and length of hospital stay. STATISTICAL ANALYSIS USED: The independent t-tests, Chi-square, or Fisher's exact test were used to evaluate the categorical variables with a repeated measures analysis of variance for inter-group comparison with P < 0.05 as significant. RESULTS: Seventy-one (36 in Group A and 35 in Group B) patients were included in the study with comparable baseline characteristics. Group A had a better acid–base status, especially after the conclusion of vascular anastomosis (pH 7.37 ± 0.06 vs. 7.33 ± 0.04, P = 0.014) and in the postoperative period (pH 7.35 ± 0.07 vs. 7.31 ± 0.05, P = 0.013). No statistically significant difference was observed in outcome parameters between the groups. CONCLUSIONS: PL may be preferred over NS due to better metabolic milieu during HNS-FFR surgery.