Background and Goal of Study:The level of dehydration that develops during  the nothing  per os (NPO) period and its impact on  intraoperative fluid management remain uncertain. Goal directed fluid therapy (GDFT) with SVV  is a simple,  hemodynamic variable for evaluating fluid responsiveness that  was associated with improved outcomes in patients undergoing high-risk surgery. The aim of this study was to investigate if there is a statistically significant difference between the total volume of fluid administered to patients who underwent surgery  in the morning (08.00 AM, first cases) versus the afternoon (12.00-15.00 PM) when using GDFT.
Materials and Methods:We retrospectively analyzed  data from  100 patients  in whom GDFT was applied intraoperatively with the FloTrac/Vigileo system and  divided them  into two groups: AM first case start (0800am start time) versus PM  case time start (1200-1500). Patients with history of CHF or ESRD, and those who received bowel preparation  were excluded.  Variables  recorded and compared between the two groups included: age, gender, American Society of Anesthesiologists class, comorbidities, body mass index, type of surgery, NPO time, blood loss, urine output, length of stay, readmission rate, fluid volumes and types, intraoperative hemodynamics, use of epidural  analgesia. Primary outcome was influence of case-start time on crystalloid and colloid volumes. Secondary outcomes were  total length of hospital stay (LOS) and  30-day readmission rates. Variables were compared using a Generalized Linear Model.
Results and Discussion:Variables found to predict total volume of fluids were ASA class (p=0.001), urine output (p<0.001),  blood loss (p<0.001), and duration of surgery (p<0.001). Age, time of day for case start, NPO time, gender, use of epidural,  weight, and height were not statistically significant predictors of total fluid volume. When including all of the model factors, there was no association between time of day and readmission  rate (p=0.96), or time of day and length of hospital stay (p=0.25).
Conclusion(s)In our study population there was no association between NPO time and fluid volume needed in patients managed with GDFT. Thus, the  use of a  formula based on the patient’s weight per unit time (ml/kg/hr) for fluid rescuscitation  may not be justified.


09 / Goal Directed Fluid Therapy and the NPO Period: Does the Case Start Time Influence Fluid Management?