Institution of prothrombin complex concentrate protocols is associated with a reduction in plasma administration at a Tertiary Care Hospital.

STUDY OBJECTIVE: Explore how the introduction of 4-factor prothrombin complex concentrates (4F-PCC) protocols for reversing anticoagulation and the treatment of critical bleeding influenced blood product utilization. DESIGN: A retrospective analysis of the utilization rate of plasma and 4F-PCC from September 2012 through December 2018. SETTING: Blood bank and pharmacy records of a single large tertiary care medical center. PATIENTS: Admitted patients except obstetric during the study period (n = 283,319). INTERVENTION: Five institutional protocols providing guidelines for 4F-PCC administration were deployed over a 3-year period. MEASUREMENTS: The utilization rate of plasma and 4F-PCC was the primary outcome and analyzed using an interrupted time series analysis. Utilization of platelets and cryoprecipitate as well as the impact of the intervention on the service prescribing the blood products were evaluated as secondary outcomes. Data were evaluated using a segmented time series regression. RESULTS: When adjusted for seasonality, the monthly rate of plasma administration was 24.7 ± 2.0 units per 100 admissions in the 6-month period prior to the 1st intervention (May-October 2013) and decreased to 9.9 ± 2.2 units per 100 admissions in the same six-month period following the 5th intervention (May-October 2018), median difference - 14.5, 95% CI -16.0 to -13.2, P < 0.001. During the 6-month period prior to the 1st intervention (May-October 2013) the monthly rate of 4-F PCC use was 1.2 ± 0.8 doses per 1000 admissions and increased to 2.8 ± 1.0 doses per 1000 admissions 6-months following the 5th intervention (May-October 2018), median difference 1.6, 95% CI 0.3 to 1.9, P = 0.014. The monthly utilization of platelets was decreased and cryoprecipitate slightly increased following the implementation of the PCC protocols. CONCLUSIONS AND RELEVANCE: Our findings demonstrate that establishing institutional protocols for the use of 4F-PCC to reverse the effects of anticoagulation and to treat critical bleeding with associated coagulopathy was associated with reduced plasma utilization.

Mitigating ethical conflict and moral distress in the care of patients on ECMO: impact of an automatic ethics consultation protocol.

AIMS: This study evaluates a protocol for early, routine ethics consultation (EC) for patients on extracorporeal membrane oxygenation (ECMO) to support decision-making in the context of clinical uncertainty with the aim of mitigating ethical conflict and moral distress. METHODS: We conducted a single-site qualitative analysis of EC documentation for all patients receiving ECMO support from 15 August 2018 to 15 May 2019 (n=68). Detailed analysis of 20 ethically complex cases with protracted ethics involvement identifies four key ethical domains: limits of prognostication, bridge to nowhere, burden of treatment and system-level concerns. There are three subthemes: relevant contextual factors, the role of EC and observed outcomes. Content analysis of transcripts from interviews with 20 members of the multidisciplinary ECMO team yields supplemental data on providers' perceptions of the impact of the early intervention protocol. RESULTS: Limited outcome data for ECMO, unclear indications for withdrawal, adverse effects of treatment and an obligation to attend to programme metrics present significant ethical challenges in the care of this patient population. Upstream EC mitigates ethical conflict by setting clear expectations about ECMO as a time limited trial, promoting consistent messaging among multiple services and supporting surrogate decision-makers. When ECMO becomes a 'bridge to nowhere', EC facilitates decision-making that respects patient values yet successfully sets limits on non-beneficial use of this novel therapy. CONCLUSION: Data from this study support the conclusion that ECMO poses unique ethical challenges that necessitate a standardised protocol for early, routine EC-at least while this medical technology is in its nascent stages.

A Randomized Controlled Trial of Low-Dose Tranexamic Acid versus Placebo to Reduce Red Blood Cell Transfusion During Complex Multilevel Spine Fusion Surgery.

BACKGROUND: Multilevel spine fusion surgery for adult deformity correction is associated with significant blood loss and coagulopathy. Tranexamic acid reduces blood loss in high-risk surgery, but the efficacy of a low-dose regimen is unknown. METHODS: Sixty-one patients undergoing multilevel complex spinal fusion with and without osteotomies were randomly assigned to receive low-dose tranexamic acid (10 mg/kg loading dose, then 1 mg·kg-1·hr-1 throughout surgery) or placebo. The primary outcome was the total volume of red blood cells transfused intraoperatively. RESULTS: Thirty-one patients received tranexamic acid, and 30 patients received placebo. Patient demographics, risk of major transfusion, preoperative hemoglobin, and surgical risk of the 2 groups were similar. There was a significant decrease in total volume of red blood cells transfused (placebo group median 1460 mL vs. tranexamic acid group 1140 mL; median difference 463 mL, 95% confidence interval 15 to 914 mL, P = 0.034), with a decrease in cell saver transfusion (placebo group median 490 mL vs. tranexamic acid group 256 mL; median difference 166 mL, 95% confidence interval 0 to 368 mL, P = 0.042). The decrease in packed red blood cell transfusion did not reach statistical significance (placebo group median 1050 mL vs. tranexamic acid group 600 mL; median difference 300 mL, 95% confidence interval 0 to 600 mL, P = 0.097). CONCLUSIONS: Our results support the use of low-dose tranexamic acid during complex multilevel spine fusion surgery to decrease total red blood cell transfusion.

Impact of Anemia and Transfusion on Readmission and Length of Stay After Spinal Surgery: A Single-center Study of 1187 Operations.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To determine whether receipt of blood transfusion and preoperative anemia are associated with increased rates of 30-day all-cause readmission, and secondarily with a prolonged hospital stay after spinal surgery. SUMMARY OF BACKGROUND DATA: Increased focus on health care quality has led to efforts to determine postsurgical readmission rates and predictors of length of postoperative hospital stay. Although there are still no defined outcome measures specific to spinal surgery to which providers are held accountable, efforts to identify appropriate measures and to determine modifiable risk factors to optimize quality are ongoing. METHODS: Records from 1187 consecutive spinal surgeries at Northwestern Memorial Hospital in 2010 were retrospectively reviewed and data were collected that described the patient, surgical procedure, hospital course, complications, and readmissions. Presence or absence of transfusion during the surgery and associated hospital course was treated as a binary variable. Multivariate negative binomial regression and logistic regression were used to model length of stay and readmission, respectively. RESULTS: Nearly one fifth (17.8%) of surgeries received transfusions, and the overall readmission rate was 6.1%. After controlling for potential confounders, we found that the presence of a transfusion was associated with a 60% longer hospital stay [adjusted incidence rate ratio=1.60 (1.34-1.91), P<0.001], but was not significantly associated with an increased rate of readmission [adjusted odds ratio=0.81 (0.39-1.70), P=0.582]. Any degree of preoperative anemia was associated with increased length of stay, but only severe anemia was associated with an increased rate of readmission. CONCLUSIONS: Both receipt of blood transfusion and any degree of preoperative anemia were associated with increased length of hospital stay after controlling for other variables. Severe anemia, but not receipt of blood transfusion, was associated with increased rate of readmission. Our findings may help define actions to reduce length of stay and decrease rates of readmission.

Evaluation of American Society of Anesthesiologists classification as 30-day morbidity predictor after single-level elective anterior cervical discectomy and fusion.

BACKGROUND CONTEXT: Higher American Society of Anesthesiologists (ASA) classification is a known predictor of postoperative complication in diverse surgical settings. However, its predictive value is not established in single-level elective anterior cervical discectomy and fusion (SLE-ACDF). PURPOSE: This study aimed to evaluate the predictive value of ASA classification system on 30-day morbidity following SLE-ACDF. DESIGN/SETTING: Patients who underwent SLE-ACDF between 2011 and 2013 were selected from the American College of Surgeons National Surgical Quality Improvement Program database. PATIENT SAMPLE: A total of 6,148 patients were selected from the 2011-2013 American College of Surgeons National Surgical Quality Improvement Program database. OUTCOME MEASURES: All outcomes are self-report measures as tracked by dedicated clinical reviewers via prospective review of inpatient charts, outpatient clinic visits, and direct contact with the surgical team. METHODS: Propensity score matching and multiple logistic regression analyses were performed to evaluate ASA classification as 30-day morbidity predictor. This study has no financial conflict and has no potential conflict of interest to disclose. RESULTS: A total of 6,148 patients were analyzed in this study. Patients in the ASA >II cohort had higher incidence of comorbidities and postoperative complications (overall complication, pneumonia, unplanned intubation, ventilator dependent >48 hours, cerebrovascular accident or stroke, catastrophic outcome, and airway complication). Propensity score matching yielded 1,628 pairs of well-matched patients. Multivariable analyses with the propensity score matched dataset revealed the following associations between ASA class >II and 30-day outcomes: any complication (odds ratio [OR] 0.82, 95% confidence interval [CI] 0.48-1.41), pneumonia (OR 1.22, 95% CI 0.33-4.56), unplanned intubation (OR 1.49, 95% CI 0.41-5.36), ventilator >48 hours (OR 5.92, 95% CI 0.69-50.96), catastrophic outcome (OR 1.02, 95% CI 0.39-2.71), and airway complication (OR 2.21, 95% CI 0.67-7.29). CONCLUSIONS: Although we did not detect associations between ASA class >II and adverse 30-day outcomes following SLE-ACDF, imprecision of estimates precludes definitive inferences. Although ASA classification allows simple assessment of patients' physiological status, their overall perioperativerisk factors need to be considered collectively for adequate optimization and improved outcomes in SLE-ACDF.

The Clinical Significance of Patient Specimen Transport Modality: Pneumatic Tube System Impact on Blood Gas Analytes.

INTRODUCTION: A pneumatic tube system (PTS) is a cost-effective, rapid transport modality that utilizes induced pressure changes. We evaluated the clinical importance of 2 transport modalities, human courier and PTS, for blood gas specimens. METHODS: Following open heart surgery, 35 simultaneous pairs of arterial and venous blood gas specimens were analyzed from 20 subjects. Of each pair, one specimen was transported to the blood gas laboratory via a human courier and the other via a SwissLog PTS. Transport modalities were compared using the Bland-Altman limits of agreement method. RESULTS: Compared with the walked specimen, the bias for PaO2 was -8.0 mm Hg (95% CI, -40.0 to 24.5 mm Hg); PaCO2 , -0.94 mm Hg (95% CI, -3.76 to 1.86 mm Hg); PvO2 , -0.60 mm Hg (95% CI, -6.90 to 5.70 mm Hg); PvCO2 , -0.58 mm Hg (95% CI, -3.12 to 1.92 mm Hg) for the PTS specimen. CONCLUSION: The difference in the PO2 and PCO2 of paired (walked vs tubed) arterial and venous blood gas specimens demonstrated a slight bias. PaO2 values demonstrated the greatest bias, however not clinically important. Thus, PTS transport does not impact clinical interpretations of blood gas values.

Nicardipine is superior to esmolol for the management of postcraniotomy emergence hypertension: a randomized open-label study.

BACKGROUND: Emergence hypertension after craniotomy is a well-documented phenomenon for which natural history is poorly understood. Most clinicians attribute this phenomenon to an acute and transient increase in catecholamine release, but other mechanisms such as neurogenic hypertension or activation of the renin-angiotensin-aldosterone system have also been proposed. In this open-label study, we compared the monotherapeutic antihypertensive efficacy of the 2 most titratable drugs used to treat postcraniotomy emergence hypertension: nicardipine and esmolol. We also investigated the effect of preoperative hypertension on postcraniotomy hypertension and the natural history of postcraniotomy hypertension in the early postoperative period. METHODS: Fifty-two subjects were prospectively randomized to receive either nicardipine or esmolol as the sole drug for treatment of emergence hypertension at the conclusion of brain tumor resection (40 subjects finally analyzed). After a uniform anesthetic, standardized protocols of these antihypertensive medications were administered for the treatment of systolic blood pressure (SBP) >130, with the goal of maintaining SBP <140 throughout the first postoperative day. In the event of study medication "failure," a "rescue" antihypertensive (labetalol or hydralazine) was used. The O'Brien-Fleming Spending Function was used to calculate the appropriate α value for each interim analysis of the primary outcome; univariate analysis was performed otherwise, with a 2-sided P<0.05 considered statistically significant. RESULTS: The incidence of nicardipine failure (5%, 95% confidence interval [CI] 0.1%-24.9%) was significantly less than that of esmolol (55%, 95% CI 31.5%-76.9%) as a sole drug in controlling SBP after brain tumor resection (difference 99% CI 13.8%-75.7%, P = 0.0012). The presence of preoperative hypertension or the approach to surgery (open craniotomy versus endonasal transsphenoidal) had no significant effect on the incidence of failure of the antihypertensive regimen used. We did not observe a difference in the need for opioid therapy for postcraniotomy pain between drug groups (99% CI difference -39.2%-30.2%). Failure of the study drug predicted the need for rescue drug therapy in the initial 12 hours after discharge from the recovery room (difference success versus failure = -41.7%, 99% CI difference -72.3% to -1.8%, P = 0.0336) but not during the period 12 to 24 hours after discharge from the recovery room (difference success versus failure = -27.4%, 99% CI difference -63.8%-9.2%, P = 0.143). However, in those patients carrying a preoperative diagnosis of hypertension, the need for rescue medication was only different during the period 12 to 24 hours after discharge from the recovery room (difference normotensive versus hypertensive = -35.4%, 99% CI difference -66.9% to -0.3%, P = 0.0254). CONCLUSIONS: Nicardipine is superior to esmolol for the treatment of postcraniotomy emergence hypertension. This type of hypertension is thought to be a transient phenomenon not solely related to sympathetic activation and catecholamine surge but also possibly encompassing other physiologic factors. For treating postcraniotomy emergence hypertension, nicardipine is a relatively effective sole drug, whereas if esmolol is used, rescue antihypertensive medications should be readily available.

A comparison of hemoglobin measured by co-oximetry and central laboratory during major spine fusion surgery.

BACKGROUND: Many factors affect the accuracy of hemoglobin concentration values. In this study, we evaluated whether the hemoglobin concentration obtained by means of arterial blood gas (ABG) co-oximetry and complete blood count (CBC) central laboratory techniques clinically correlate when using simultaneous measurements of hemoglobin concentration obtained during complex spine fusion surgery. METHODS: Three hundred forty-eight patients who underwent spinal fusion of >3 bony levels between September 2006 and September 2010, with concurrent ABG and CBC samples, were identified. The mean difference between pairs of measured hemoglobin values was determined using limits of agreement analysis. Error grid analysis was used to delineate correlation of samples in relation to hemoglobin values within the range considered for transfusion. RESULTS: The median difference (ABG-CBC) between the measured hemoglobin values was 0.4 g/dL (95% confidence interval [CI], 0.35-0.40 g/dL; P < 0.0001). Limits of agreement analysis correcting for repeated observations in multiple patients demonstrated that the mean difference between measured hemoglobin values (i.e., bias) was 0.4 g/dL (95% CI, 0.36-0.41 g/dL), and the 95% limits of agreement of the difference between paired measurements were -0.70 to 1.47 g/dL. The magnitude of the difference between the measured hemoglobin values was >0.5 g/dL in 44.5% of patients (95% CI, 42.2%-46.8%); however, 6.8% (95% CI, 5.8%-8.1%) of paired measurements had a difference of >1.0 g/dL. There was only fair-to-moderate agreement between the CBC and ABG values within the clinically significant range of hemoglobin values of 7 to 10 g/dL (Cohen κ = 0.39; 95% CI, 0.33-0.45). CONCLUSIONS: The hemoglobin values obtained from ABG and CBC cannot be used interchangeably when verifying accuracy of novel point-of-care hemoglobin measurement modalities or when managing a patient with critical blood loss.

The implementation and efficacy of the Northwestern High Risk Spine Protocol.

OBJECTIVE: The aims of this study were to determine the efficacy and feasibility of implementation of the intraoperative component of a high risk spine (HRS) protocol for improving perioperative patient safety in complex spine fusion surgery. METHODS: In this paired availability study, the total number of red blood cell units transfused was used as a surrogate marker for our management protocol efficacy, and the number of protocol violations was used as a surrogate marker for protocol compliance. RESULTS: The 548 patients (284 traditional vs. 264 HRS protocol) were comparable in all demographics, coexisting diseases, preoperative medications, type of surgery, and number of posterior levels instrumented. However, the surgical duration was 70 minutes shorter in the new group (range, 32-108 minutes shorter; P < 0.0001) and the new protocol patients received a median of 1.1 units less of total red blood cell units (range, 0-2.4 units less; P = 0.006). There were only 7 (2.6%) protocol violations in the new protocol group. CONCLUSIONS: The intraoperative component of the HRS protocol, based on two Do-Confirm checklists that focused on 1) organized communication between intraoperative team members and 2) active maintenance of oxygen delivery and hemostasis appears to maintain a safe intraoperative environment and was readily implemented during a 3-year period.

Predicting major adverse cardiac events in spine fusion patients: is the revised cardiac risk index sufficient?

STUDY DESIGN: Observational cohort study. OBJECTIVE: To determine the accuracy of the Revised Cardiac Risk Index (RCRI) in predicting major adverse cardiac events in patients undergoing spine fusion surgery of 3 levels or more. SUMMARY OF BACKGROUND DATA: Preoperative cardiac testing is extensively guided by the RCRI, which was developed and validated in thoracic, abdominal, and orthopedic surgical patients. Because multilevel spine fusion surgery is often associated with major transfusion, we hypothesize that the RCRI may not accurately characterize the risk of cardiovascular morbidity in these patients. METHODS: After institutional review board approval, perioperative data were collected from 547 patients who underwent 3 or more levels of spinal fusion with instrumentation. Postoperative cardiac morbidity was defined as any combination of the following: arrhythmia requiring medical treatment, myocardial infarction (either by electrocardiographic changes or troponin elevation), or the occurrence of demand ischemia. The surgical complexity was categorized as anterior surgery only, posterior cervical and/or thoracic fusion, posterior lumbar fusion, or any surgery that included transpedicular osteotomies. Logistic regression analysis was performed to determine RCRI performance. RESULTS: The RCRI performed no better than chance (area under the curve = 0.54) in identifying the 49 patients (9%) who experienced cardiac morbidity. CONCLUSION: The RCRI did not predict cardiac morbidity in our patients undergoing major spine fusion surgery, despite being extensively validated in low-risk noncardiac surgical patients. Preoperative testing and optimization decisions, previously based on the RCRI, may need to be revised to include more frequent functional cardiac imaging and more aggressive implementation of pharmacologic modalities that may mitigate cardiac morbidity, similar to the preoperative evaluation for major vascular surgery. LEVEL OF EVIDENCE: 3.

Development and validation of a generalizable model for predicting major transfusion during spine fusion surgery.

BACKGROUND: Surgery for posterior spine instrumentation often requires major transfusion. The aim of this study was to develop and test the validity of a model for predicting intraoperative major transfusion (>4 U total red blood cells), based on preoperative patient and surgical variables, that was applicable to adult patients undergoing cervical, thoracic, and/or lumbar spine deformity surgery with and without osteotomies. MATERIALS AND METHODS: The perioperative data from 548 patients who underwent ≥ 3 levels of posterior spinal fusion with instrumentation between January 1, 2003 and May 30, 2009, were retrospectively collected to create a model for predicting major blood transfusion. The validity of the model was retrospectively tested with a separate data set of 95 patients who underwent surgery from June 1, 2009 through September 30, 2010. RESULTS: There was a 59.5% incidence of major transfusion in the derivation set of patients. Independent predictors of major transfusion were operation duration, number of posterior levels instrumented, surgical complexity score, and preincision hemoglobin. This model was able to predict major transfusion significantly better than a previously published model (ROCAUC=0.89; 99% confidence interval, 0.80-0.90; P<0.001). CONCLUSIONS: Our model has an increased accuracy for predicting the probability of major transfusion compared with a previously published model. In addition, our model is applicable to all types of spine fusion surgery and accounts for the complexity of surgical instrumentation, the number of levels instrumented, and the predicted duration of surgery as independent variables.

Renin-angiotensin system inhibitors and troponin elevation in spinal surgery.

Renin-angiotensin system (RAS) inhibition by angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) has been shown to reduce cardiovascular mortality and non-fatal myocardial infarction (MI) in high-risk surgical patients. However, their effect in spinal surgery has not been explored. Our objective was to determine the effect of RAS inhibitors on postoperative troponin elevation in spinal fusions, and to examine their correlation with hospital stay. We retrospectively analyzed 208 consecutive patients receiving spinal fusions ⩾5 levels between 2007-2010 with a mean follow-up of 1.7 years. Inclusion criteria were age ⩾18 years, elective fusions for kyphoscoliosis, and semi-elective fusions for tumor or infection. Exclusion criteria were trauma and follow-up <1 year. Descriptives, frequencies, and logistic and linear regression were used to analyze troponin elevation (⩾0.04 ng/mL), peak troponin level, and hospital stay. The results featured 208 patients with a mean body mass index (BMI) 28.5 kg/m(2) who underwent 345 spinal fusions. ACEI/ARB were withheld the day prior to surgery in 121 patients with 11 patients noteworthy for intra-operative electrocardiogram changes, 126 patients with troponin elevation, and 14 MI identified prior to discharge. Multivariate logistic regression identified BMI (p=0.04), estimated blood loss (p=0.015), and preoperative ACEI/ARB (p=0.015, odds ratio=2.7) as significant independent predictors for postoperative troponin elevation. Multivariate linear regression showed preoperative Oswestry Disability Index (p=0.002), unplanned return to operating room (p=0.007), pneumonia prior to hospital discharge (p<0.01), and preoperative ACEI/ARB to be associated with hospital stay. In patients with spinal fusions ⩾5 levels, ACEI/ARB are independently associated with postoperative troponin elevation and increased hospital stay.