Postoperative Acute Kidney Injury is Associated with Persistent Renal Dysfunction: A Multicenter Propensity Matched Cohort Study.

Background: The risk of developing a persistent reduction in renal function after postoperative acute kidney injury (pAKI) is not well-established. Objective: Perform a multi-center retrospective propensity matched study evaluating whether patients that develop pAKI have a greater decline in long-term renal function than patients that did not develop postoperative AKI. Design: Multi-center retrospective propensity matched study. Setting: Anesthesia data warehouses at three tertiary care hospitals were queried. Patients: Adult patients undergoing surgery with available preoperative and postoperative creatinine results and without baseline hemodialysis requirements. Measurements: The primary outcome was a decline in follow-up glomerular filtration rate (GFR) of 40% relative to baseline, based on follow-up outpatient visits from 0-36 months after hospital discharge. A propensity score matched sample was used in Kaplan-Meier analysis and in a piecewise Cox model to compare time to first 40% decline in GFR for patients with and without pAKI. Results: A total of 95,208 patients were included. The rate of pAKI ranged from 9.9% to 13.7%. In the piecewise Cox model, pAKI significantly increased the hazard of a 40% decline in GFR. The common effect hazard ratio was 13.35 (95% CI: 10.79 to 16.51, p<0.001) for 0-6 months, 7.07 (5.52 to 9.05, p<0.001) for 6-12 months, 6.02 (4.69 to 7.74, p<0.001) for 12-24 months, and 4.32 (2.65 to 7.05, p<0.001) for 24-36 months. Limitations: Retrospective; Patients undergoing ambulatory surgery without postoperative lab tests drawn before discharge were not captured; certain variables like postoperative urine output were not reliably available. Conclusion: Postoperative AKI significantly increases the risk of a 40% decline in GFR up to 36 months after the index surgery across three institutions.

Self-reported Race/Ethnicity and Intraoperative Occult Hypoxemia: A Retrospective Cohort Study.

BACKGROUND: Pulse oximetry is ubiquitous in anesthesia and is generally a reliable noninvasive measure of arterial oxygen saturation. Concerns regarding the impact of skin pigmentation and race/ethnicity on the accuracy of pulse oximeter accuracy exist. The authors hypothesized a greater prevalence of occult hypoxemia (arterial oxygen saturation [Sao2] less than 88% despite oxygen saturation measured by pulse oximetry [Spo2] greater than 92%) in patients undergoing anesthesia who self-reported a race/ethnicity other than White. METHODS: Demographic and physiologic data, including self-reported race/ethnicity, were extracted from a departmental data warehouse for patients receiving an anesthetic that included at least one arterial blood gas between January 2008 and December 2019. Calculated Sao2 values were paired with concurrent Spo2 values for each patient. Analysis to determine whether Black, Hispanic, Asian, or Other race/ethnicities were associated with occult hypoxemia relative to White race/ethnicity within the Spo2 range of 92 to 100% was completed. RESULTS: In total, 151,070 paired Sao2-Spo2 readings (70,722 White; 16,011 Black; 21,223 Hispanic; 8,121 Asian; 34,993 Other) from 46,253 unique patients were analyzed. The prevalence of occult hypoxemia was significantly higher in Black (339 of 16,011 [2.1%]) and Hispanic (383 of 21,223 [1.8%]) versus White (791 of 70,722 [1.1%]) paired Sao2-Spo2 readings (P < 0.001 for both). In the multivariable analysis, Black (odds ratio, 1.44 [95% CI, 1.11 to 1.87]; P = 0.006) and Hispanic (odds ratio, 1.31 [95% CI, 1.03 to 1.68]; P = 0.031) race/ethnicity were associated with occult hypoxemia. Asian and Other race/ethnicity were not associated with occult hypoxemia. CONCLUSIONS: Self-reported Black and Hispanic race/ethnicity are associated with a greater prevalence of intraoperative occult hypoxemia in the Spo2 range of 92 to 100% when compared with self-reported White race/ethnicity.

Comparison of surgical invasiveness and morbidity of adult spinal deformity surgery to other major operations.

BACKGROUND CONTEXT: Adult spinal deformity (ASD) surgeries are complex, involving long operative times and surgical morbidity. It is currently unclear how the invasiveness of ASD surgery compares to other major operations. PURPOSE: To: (1) develop a quantitative score of surgical morbidity and invasiveness, and (2) compare this score between ASD surgery and other major operations. STUDY DESIGN: Retrospective review of prospectively collected data. PATIENT SAMPLE: A prospective surgical registry was used to identify all patients undergoing ASD surgery involving ≥ 7 segments. Seventeen additional procedures were included: coronary artery bypass grafting (CABG), pancreatectomy, and esophagectomy, among others. OUTCOME MEASURES: Perioperative factors (operative time, transfusions, ventilation) and complications were collected and combined with a previously validated Postoperative Morbidity Survey to create a Surgical Invasiveness and Morbidity Score (SIMS). METHODS: Computed scores were compared across surgeries using Welch's t-test. Multiple linear regression modeling was used to compare the SIMS of major surgeries relative to ASD while controlling for patient demographics and comorbidities. RESULTS: A total of 1,245,282 surgical patients were included, 4,656 of which underwent ASD surgery. After multiple regression modeling controlling for patient demographics and comorbidities, ASD surgery ranked fourth in SIMS. ASD surgery had a significantly greater SIMS than 13 other major procedures including 6th esophagectomy (adjusted mean difference=-0.05, 95%CI -0.01-0.09, p<.001), 8th pancreatectomy (-0.40, 0.37-0.44, p<.001), 11th craniotomy for tumor (-1.01, 0.98-1.04, p<.001), and 12th sacral chordoma resection (-1.31, 1.26-1.37, p<.001). CONCLUSIONS: ASD surgery was associated with significantly greater SIMS than many other major operations, even when controlling for important perioperative factors. These data have implications for patient counseling, resource allocation, and informed consent.

Regional cerebral oximetry is consistent across self-reported racial groups and predicts 30-day mortality in cardiac surgery: a retrospective analysis.

Darker skin pigmentation appears to cause underestimation of regional oxygen saturation (rSO2) for certain cerebral oximetry devices. This presents a risk of triggering unindicated interventions and may limit its utility for predicting adverse outcomes. Our goal was to quantify the impact of self-reported race on oximetry measurements during cardiac surgery and elucidate whether race has a mediating role in the association of rSO2 with mortality. Data was extracted from our department's data warehouse for adult patients who underwent on-pump cardiac surgery between June 2014 and June 2018. Intraoperative rSO2 was recorded every 15 s throughout all cases. After grouping patients by self-reported race, multiple linear regression modeling was utilized to assess the association between race and mean pre-bypass rSO2 while controlling for various perioperative variables. The role of mean pre-bypass rSO2 for predicting 30-day mortality was evaluated via multiple logistic regression, and the threshold for rSO2 was selected by maximizing F1 score. There were 4267 patients included. Compared to Caucasian patients, the unadjusted difference in mean pre-bypass rSO2 was - 0.6% (95% CI - 1.3 to 0.04) for African American patients, - 1.8% (- 2.7 to - 0.9) for Asian patients, 0.1% (- 0.8 to 1.0) for Hispanic patients, - 1.6% (- 3.0 to - 0.4) for Indian/South Asian patients, and - 1.4% (- 3.7 to 0.9) for Pacific Islander patients. After adjusting for perioperative variables, differences in rSO2 readings less than 2% were observed between racial groups. Mean pre-bypass rSO2 under 63% was an independent predictor of higher 30-day mortality risk (OR: 2.86, CI 1.39 to 5.53, p = 0.003), and the interaction variable between rSO2 and race was not statistically significant (p = 0.299). Cerebral oximetry measurements are more consistent across racial groups than previously reported, supporting its utility for intraoperative monitoring and risk stratification. Pre-intervention rSO2 is associated with increased 30-day mortality at a higher threshold than previously reported and was not significantly impacted by self-reported race.

Finding a proper "Mate": Comparison of left ventricular assist devices using cerebral oximetry.

INTRODUCTION: Axial-flow and centrifugal-flow left ventricular assist devices (LVAD) have been utilized in the management of heart failure, but it remains unknown whether these devices differ in end-organ perfusion. Our goal was to evaluate the association between device type and regional cerebral oxygen saturation (rSO2), and determine if this confers any benefit in short-term postoperative outcomes. METHODS: Adult patients who underwent primary LVAD implantation at our institution from 2014 to 2019 were retrospectively analyzed. Patients were stratified into axial-flow and centrifugal-flow groups. Intraoperative rSO2 readings were used to calculate the change in mean rSO2 from pre- to post-bypass. Multivariable modeling was performed to compare delta rSO2 between groups, and to analyze the association between LVAD type and postoperative outcomes. RESULTS: There were 152 patients included, of which 76 had an axial-flow device and 76 had a centrifugal-flow device implanted. The rSO2 level increased from pre-bypass to post-bypass on average 3.5% (CI: 2.1 to 5.0) for the axial group compared to 0.1% (CI: -1.2 to 1.4) for the centrifugal group, which was a significant difference (ß = -2.22, CI: -4.21 to -0.32, p = 0.022). Axial devices approached significance for lower odds of postoperative complications (OR: 0.35, CI: 0.11 to 1.06, p = 0.063), and were associated with significantly shorter ICU LOS (ß = -0.36, CI: -0.60 to -0.11, p = 0.004). CONCLUSION: Axial devices resulted in a greater increase in rSO2 than centrifugal pumps after separation from CPB. Further investigation is warranted to evaluate the effect of LVAD selection on long-term end-organ perfusion and subsequent patient outcomes.

Preoperative Risk Stratification in Spine Tumor Surgery: A Comparison of the Modified Charlson Index, Frailty Index, and ASA Score.

STUDY DESIGN: A retrospective review of prospectively collected data. OBJECTIVE: The purpose of this study is to compare and validate several preoperative scores for predicting outcomes following spine tumor resection. SUMMARY OF BACKGROUND DATA: Preoperative risk assessment for patients undergoing spinal tumor resection remains challenging. At present, few risk assessment tools have been validated in this high-risk population. METHODS: The 2008 to 2014 National Surgical Quality Improvement database was used to identify all patients undergoing surgical resection of spinal tumors, stratified as extradural, intradural extramedullary, and intramedullary based on CPT codes. American Society of Anesthesiologists (ASA) score, modified Charlson Comorbidity Index (CCI), and modified Frailty Index (mFI) were computed. A binary logistic regression model was used to explore the relationship between these variables and postoperative outcomes, including mortality, major and minor adverse events, and hospital length of stay (LOS). Other significant variables such as demographics, operative time, and tumor location were controlled for in each model. RESULTS: Two thousand one hundred seventy patients met the inclusion criteria. Higher CCI scores were independent predictors of mortality (OR = 1.24, 95% CI: 1.14-1.36, P < 0.001), major adverse events (OR = 1.07, 95% CI: 1.01-1.31, P = 0.018), minor adverse events (OR = 1.15, 95% CI: 1.10-1.20, P < 0.001), and prolonged LOS (OR = 1.14, 95% CI: 1.09-1.19, P < 0.001). Patients' mFI scores were significantly associated with mortality and LOS, but not major or minor adverse events. ASA scores were not associated with any outcome metric when controlling for other variables. CONCLUSION: The CCI demonstrated superior predictive capacity compared with mFI and ASA scores and may be valuable as a preoperative risk assessment tool for patients undergoing surgical resection of spinal tumors. The validation of assessment scores is important for preoperative risk stratification and improving outcomes in this high-risk group. LEVEL OF EVIDENCE: 3.

Incidence and Predictive Factors of Sepsis Following Adult Spinal Deformity Surgery.

BACKGROUND: Surgery for adult spinal deformity (ASD) improves quality of life, yet morbidity is high. Sepsis is a challenging postoperative complication that can result in death and drive inpatient resources. OBJECTIVE: To identify the incidence and risk factors for development of sepsis within 30 days following ASD surgery. METHODS: Adult patients who underwent thoracolumbar spinal deformity correction between 2008 and 2014 were identified in the National Surgical Quality Improvement Program database. Demographic and operative variables were extracted. The primary outcome was development of postoperative sepsis. Multivariable logistic regression modeling was used to identify independent risk factors for sepsis. RESULTS: A total of 6158 patients underwent ASD surgery. Of these, 156 (2.5%) developed sepsis postoperatively. Independent risk factors included operative time (odds ratio [OR]: 1.004, 95% confidence interval [CI]: 1.003-1.005, P < .001), male sex (OR: 1.47, 95% CI: 1.05-2.05, P = .023), diabetes (OR: 1.59, 95% CI: 1.05-2.40, P = .027), functional dependency (OR: 1.82, 95% CI: 1.12-2.95, P = .015), weight loss (OR: 2.45, 95% CI: 1.04-5.78, P = .040), bleeding disorder (OR: 2.58, 95% CI: 1.34-4.93, P = .004), and ascites (OR: 56.11, 95% CI: 5.01-628.50, P = .001). This model demonstrated strong predictive capacity, with an area under the curve of 0.80. Patients who developed sepsis were significantly more likely to have a prolonged hospital stay (P < .001), be readmitted (P < .001), and die (P < .001). The median (range) time to sepsis was 9 d (0-30). CONCLUSION: In patients undergoing ASD surgery, male sex, diabetes, ascites, bleeding disorder, functional dependency, excessive weight loss and increased operative time independently predicted sepsis. This perioperative patient profile can be used for preoperative risk assessment, patient counseling, and postoperative management for patients undergoing ASD surgery.

Utility of Intraoperative Monitoring in the Resection of Spinal Cord Tumors: An Analysis by Tumor Location and Anatomical Region.

STUDY DESIGN: Retrospective review of institutional data. OBJECTIVE: The aim of this study was to assess the utility of somatosensory-evoked potentials (SSEP) and transcranial electric motor-evoked potentials (MEP) in the resection of spine tumors and evaluate the ability of both single and multi-modal monitoring to predict postoperative neurological deficits. SUMMARY OF BACKGROUND DATA: Although the utility of intraoperative monitoring (IOM) is well established in scoliosis and degenerative surgery, studies in spine tumor patients have been limited. METHODS: A series of consecutive patients who underwent resection with the use of IOM at a single institution between August 2009 and March 2013 was identified. Demographic, clinical, and neuromonitoring data were collected preoperatively, during surgery, at the moment of discharge, and at a 6-month follow-up visit. Three cohorts were established based on the anatomical location of the tumor: intramedullary, intradural extramedullary, and extradural. Additional groupings were formed based on spinal region. Patients with significant changes in SSEPs or MEPs during surgery were identified and the rate of neurological deficits was assessed. RESULTS: A total of 52 patients were analyzed. A change in SSEPs or MEPs was detected in 11 (21.2%) cases whereas 14 patients (26.9%) developed permanent postoperative deficits. SSEPs predicted deficits in the resection of intramedullary tumors (P = 0.015) (area under cover, AUC = 0.83), and intradural extramedullary tumors (P = 0.048; AUC = 0.70). MEP monitoring did not predict postoperative deficits in the resection of intramedullary (P = 0.21; AUC = 0.69) or intradural extramedullary tumors (P = 0.31; AUC = 0.63). Neither SSEPs nor MEPs predicted deficits for extradural tumors. CONCLUSION: The efficacy of IOM in spine tumor resection is dependent on tumor location relative to the spinal cord and dura. The accuracy of SSEPs and their ability to predict postoperative deficits was greatest for intramedullary lesions. For this series, MEP and multi-modal monitoring did not confer a benefit in predicting permanent neurological deficits. LEVEL OF EVIDENCE: 4.