P94. Massive variation exists in intraoperative IV fluid management and this correlates with complications, ICU, and LOS: a call for standardization

BACKGROUND CONTEXT Recently, there has been increased attention to optimization of intraoperative IVF management with implementation of ERAS protocols. Very large population studies for elective, non-spine surgeries have shown variability in IVFs and association with perioperative complications. Spine surgery, especially adult spinal deformity (ASD) surgery is extensive and fluid mismanagement has the potential to drastically impact the recovery and complication profiles. Regardless of the recent push towards standardization and utilizing goal-directed fluid therapy the relationship between IVF management during ASD surgery and immediate perioperative metrics has yet to be determined. PURPOSE Our goal was to evaluate IVF variability in ASD surgery and evaluate the association, if any, to in-hospital complications, ICU, and length of stay (LOS). STUDY DESIGN/SETTING Prospective multicenter comparative cohort study. PATIENT SAMPLE Operative ASD pts with minimum 6-week followup. OUTCOME MEASURES In-hospital complications, ICU admission and duration, and LOS. METHODS Operative ASD pts with minimum 6-week followup were included. Total IVF volume (tIVF, ml) was calculated by adding total crystalloid volume and total colloid volume. This was normalized to patient weight (kg) and operative time (hr) (nIVF, ml/kg/hr). The Crystalloid/colloid (C:C) ratio was also evaluated. We compared each site and enrollment time frame (10/2008-02/2020) was divided into quartiles (based on enrollment distribution) to evaluate trends over time. Sites with greater than 50 patients were included in the variability analysis. Uni- (UVA) and multivariate (MVA) analysis were utilized to determine correlation with in-hospital complications, ICU, and LOS. RESULTS A total of 798 ASD pts were included with a mean age 61.5yrs, 69.9% female, BMI 28.4 kg/m2, with 9 median levels fused and 17.9% having a 3-column osteotomy. Eight of 21 sites accounted for 84.5% (674/798) of the patients. Mean tIVF, nIVF, and C:C all had significant variation (p-0.00) with a 4.8-fold difference (range:1560-7412ml), 3.7-fold difference (range:3.4-12.5ml/kg/hr), and 4.9-fold difference (range:2.1-10.2), respectively. Over the study time frame (2008-2020), there was not a change in mean tIVF or nIVF. C:C increased (less colloid) (p-0.014) to 7.0 from 4.6 in the 2016-17 time interval. There were 292 patients (11.5%) with an in-hospital complication. An increasing tIVF correlated with higher in-hospital complications (p-0.00), ICU admission (p-0.00), ICU duration (p-0.00), and LOS (p-0.00) on univariate analysis. Multivariate analysis controlling for patient (age, frailty, revision) and surgical (invasiveness, interbody, levels fused, osteotomy, 3-CO) factors showed fluid balance (in[tIVF + cell saver]-out[EBL + urine output]) as an independent predictor of LOS and complications. CONCLUSIONS There is a 4.8-fold difference with regards to intraoperative IVF volume in ASD surgery and this correlates with complications, ICU, and LOS. Future efforts should focus on standardization and the potential impact with techniques such as goal-directed fluid therapy. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs. Recently, there has been increased attention to optimization of intraoperative IVF management with implementation of ERAS protocols. Very large population studies for elective, non-spine surgeries have shown variability in IVFs and association with perioperative complications. Spine surgery, especially adult spinal deformity (ASD) surgery is extensive and fluid mismanagement has the potential to drastically impact the recovery and complication profiles. Regardless of the recent push towards standardization and utilizing goal-directed fluid therapy the relationship between IVF management during ASD surgery and immediate perioperative metrics has yet to be determined. Our goal was to evaluate IVF variability in ASD surgery and evaluate the association, if any, to in-hospital complications, ICU, and length of stay (LOS). Prospective multicenter comparative cohort study. Operative ASD pts with minimum 6-week followup. In-hospital complications, ICU admission and duration, and LOS. Operative ASD pts with minimum 6-week followup were included. Total IVF volume (tIVF, ml) was calculated by adding total crystalloid volume and total colloid volume. This was normalized to patient weight (kg) and operative time (hr) (nIVF, ml/kg/hr). The Crystalloid/colloid (C:C) ratio was also evaluated. We compared each site and enrollment time frame (10/2008-02/2020) was divided into quartiles (based on enrollment distribution) to evaluate trends over time. Sites with greater than 50 patients were included in the variability analysis. Uni- (UVA) and multivariate (MVA) analysis were utilized to determine correlation with in-hospital complications, ICU, and LOS. A total of 798 ASD pts were included with a mean age 61.5yrs, 69.9% female, BMI 28.4 kg/m2, with 9 median levels fused and 17.9% having a 3-column osteotomy. Eight of 21 sites accounted for 84.5% (674/798) of the patients. Mean tIVF, nIVF, and C:C all had significant variation (p-0.00) with a 4.8-fold difference (range:1560-7412ml), 3.7-fold difference (range:3.4-12.5ml/kg/hr), and 4.9-fold difference (range:2.1-10.2), respectively. Over the study time frame (2008-2020), there was not a change in mean tIVF or nIVF. C:C increased (less colloid) (p-0.014) to 7.0 from 4.6 in the 2016-17 time interval. There were 292 patients (11.5%) with an in-hospital complication. An increasing tIVF correlated with higher in-hospital complications (p-0.00), ICU admission (p-0.00), ICU duration (p-0.00), and LOS (p-0.00) on univariate analysis. Multivariate analysis controlling for patient (age, frailty, revision) and surgical (invasiveness, interbody, levels fused, osteotomy, 3-CO) factors showed fluid balance (in[tIVF + cell saver]-out[EBL + urine output]) as an independent predictor of LOS and complications. There is a 4.8-fold difference with regards to intraoperative IVF volume in ASD surgery and this correlates with complications, ICU, and LOS. Future efforts should focus on standardization and the potential impact with techniques such as goal-directed fluid therapy.