Relation between preoperative fasting time and the plestimographic variability index (PVI)

Abstract

Preoperative fasting can also lead to physiological deleterious effects such as dehydration, and hypovolemia. The Plethysmographic Variability Index (PVI, Masimo Corp, Irvine, CA, USA), is a dynamic measurement and its variability could be related to hydration status. Objective: Find a correlation between the number of hours of preoperative fasting and the measurements of PVI. Studio and design: Experimental, prospective, longitudinal. Material and methods: During one-year, patients ASA I scheduled for elective general anesthesia, in an outpatient plastic surgery clinic, the nurse staff recorded PVI (%) values by MightySat® Masimo finger oximeter pulse and the hours of fasting carried out the night before their admission by direct interrogation of the patient. a simple linear regression with Pearson correlation coefficient, perfect = 1, to find a relation between fasting hours and PVI, being considered significant with a p< 0.05. Results: 140 patients were included, women (90%), mean age 35 years, the mean PVI values were 21.01 (SD +/- 7.20) means hours of preoperative fasting performed by patients 11.85 (SD+/- 2.34). Pearson correlation coefficient between fasting hours and PVI was 0.005 (t-student 0.0054, p bilateral 0.47) Conclusion: This study did not show a linear relation, direct or inverse, between fasting hours and PVI values. PVI as a dynamic measurement of preload or stroke volume did not show changes in terms of fasting time in our patients.