Preoperative Hypovitaminosis D Can Predict Development of Postoperative Cognitive Dysfunction

Abstract

Objectives: Preoperative estimation of serum 25OH-vitamin D (25OHD) level in patients undergoing surgical procedures extending for >60min under sevoflurane anesthesia and correlate these levels with frequency of postoperative (PO) cognitive dysfunction (POCD).Patients & Methods: 254 patients; 127 Kuwaiti (Group A) and 127 Egyptian patients (Group B) were evaluated clinically and gave blood samples for ELISA estimation of serum 25OHD. Vitamin D sufficiency status was defined as sufficient (≥75nmol/L), insufficient (50-75nmol/L) and deficient (<50nmol/L) level. Cognitive function was assessed preoperatively, 48-hr, 1-wk and 2-wk PO using the Digit span (DS) test. Anesthetic was induced using propofol, fentanyl and rocuronium, and was maintained with sevoflurane, fentanyl and rocuronium with continuous non-invasive hemodynamic monitoring. Study outcome included the frequency and severity of hypovitaminosis D (HVD) and POCD in studied patients.Results: Only 31 patients (12.2%) had sufficient VD level with significant difference in favor of Group B. All surgeries were conducted uneventfully within mean operative time of 154.4±37min and mean blood loss of 415±158ml. Median preoperative DS score was 6, at 48-hr, 1-wk and 2-wk PO, 153, 124 and 95 patients, respectively had score of <6. Preoperative serum 25OHD level showed negative significant correlation with age and BMI, and positive significant correlation with male gender and duration of education. Median PO score on DS testing showed positive significant correlation with serum 25OHD, especially in Kuwaiti patients. Statistical analyses defined preoperative low serum 25OHD as significant specific predictor for POCD. Conclusion:POCD is a common incident event among patients underwent major surgeries consuming long operative time under sevoflurane anesthesia. Old age, high BMI, duration and severity of surgery are co-factors for POCD. Preoperative HVD has a pronounced effect and correlated with these precipitating factors and could be used as independent significant predictor for POCD.