Perioperative Risk Assessment Research Articles

Perioperative Stroke: Risk Assessment, Prevention and Treatment

Numerous risk factors for perioperative stroke have been identified and many are modifiable. Surgical patients with a history of cerebrovascular disease should be evaluated by a neurologist. Cardiac and cerebrovascular testing is critical in identifying patients at high risk for perioperative stroke. The identification and treatment of carotid disease in the context of upcoming surgery has been a source of controversy. Routine carotid revascularization performed with coronary artery bypass graft (CABG) surgery for incidentally discovered carotid stenosis is not recommended. Prior to aortic manipulation during CABG, epiaortic ultrasound should be performed to identify aortic atheromatous plaques. If possible, preoperative aspirin, beta blocker, statin, and angiotensin converting-enzyme (ACE) inhibitor therapy should be continued in the perioperative period. Patients who are prescribed anticoagulation at high risk of thromboembolism should receive bridging anticoagulation during the perioperative period. The identification and prevention of postoperative atrial fibrillation (AF) is central to stroke prevention. CABG patients should be initiated on beta blockade +/- amiodarone to prevent postoperative AF. Many practitioners have been traditionally nihilistic towards acute perioperative stroke treatment. Given the narrow therapeutic window of treatment options, candidacy is dependent on timely recognition. Intravenous and endovascular thrombolysis/therapies are viable options in selected patients under the guidance and expertise of a neurologist. This article will present the epidemiology of perioperative stroke, the pathophysiology, risk assessment and stratification for common surgeries. The article will additionally focus on treatment options including modifiable risk factor reduction and the perioperative management of medications.

Calificación de riesgo operatorio en cirugía de tórax no cardíaca

Assessment of surgical risk is essential when submitting patients to a procedure in order to avoid perioperative complications. Lengthy wait times in performing such assessment create important delays for surgical solution. An updating of the conventional assessment (Goldman) was performed by incorporating lung, kidney and cardiac risk rates to improve prediction of morbidity and mortality, merging them into a single, comprehensive assessment (CARIOPE- Spanish initials for Perioperative Risk Rating), obtaining a fi nal score by adding individual rates, which yielded three statistically signifi cant risk levels. A prospective, observational, and descriptive study was conducted, applying CARIOPE to each patient who underwent non- ambulatory, non-cardiac surgery from September 1, 2010 to May 18, 2012, with a patient follow up during the fi rst 30 postoperative days to document morbidity and mortality in each risk level. Statistical analysis was performed using PASW statistics v.18 yielding a total of 1,097 patients, a morbidity of 12.3%, and a mortality of 3.3%. Statistically signifi cant values were obtained for the prediction of cardiac, lung, and kidney complications, among others (p < 0.05). CARIOPE is an effective tool for the assessment of perioperative risk in various organ systems and is not confi ned to cardiac risk. Key word: Preoperative assessment, surgical risk index, surgical complications, morbidity and mortality rate.

Pathologic Q Waves and Prolonged QTc Time in Preoperative ECG Are Predictive for Perioperative Cardiovascular Events

Aims: The value of ECG in the perioperative risk stratification under modern treatment options is uncertain. The main objective of the present analysis was to determine the usefulness of a pre-operative ECG derivation for evaluating the risk of perioperative morbidity and mortality. Methods: We performed a secondary analysis of the prospective, international, multicenter, observational “No-Risk” Study (N-terminal B-type natriuretic peptide [NT-proBNP] for the assessment of the perioperative cardiac risk after major noncardiac surgery) to determine the prognostic value of 12-lead ECG. Inclusion criteria were age >55 years and at least one of the following cardiovascular risk factors: arterial hypertension, diabetes mellitus, dyslipidemia, active smoking, and family history positive for coronary heart disease. The combined primary endpoint included total mortality, acute myocardial infarction (NSTEMI and STEMI), cardiopulmonary resuscitation, heart failure, and asystole or ventricular fibrillation during hospitalization. ECGs from 616 patients enrolled from 2006 to 2009 prior to noncardiac surgery in the No-Risk Study were analyzed. Results: The mean age was 67.6 (±8.1) years; 300 (48.7%) patients were male. Fourteen (2.3%) patients suffered from the combined primary endpoint while in the hospital. In Kaplan-Meier analyses, a pathologic Q wave and QTc > 500 ms were significantly related to the incidence of the primary endpoint (p p = 0.042, respectively), whereas other ECG parameters such as LBBB, RBBB, PQ interval, QRS interval, and others were not related to worse in-hospital outcome. Conclusion: The 12-lead ECG is still an important diagnostic tool for perioperative risk assessment of cardiovascular events in noncardiac surgery in patients at risk.

Patient frailty: the elephant in the operating room

For most surgeons and many anaesthetists, patient frailty is currently the 'elephant in the (operating) room': it is easy to spot, but is often ignored. In this paper, we discuss different approaches to the measurement of frailty and review the evidence regarding the effect of frailty on peri-operative outcomes. We explore the limitations of 'eyeballing' patients to quantify frailty, and consider why the frail older patient, challenged by seemingly minor insults in the postoperative period, may suffer falls or delirium. Frailty represents a state of increased vulnerability to stressors, and older inpatients are exposed to multiple stressors in the peri-operative setting. Quantifying frailty is likely to increase the precision of peri-operative risk assessment. The Frailty Index derived from Comprehensive Geriatric Assessment is a simple and robust way to quantify frailty, but is yet to be systematically investigated in the pre-operative setting. Furthermore, the optimal care for frail patients and the reversibility of frailty with prehabilitation are fertile areas for future research.

Diagnosis, Successful Hemostasis and Peri-Operative Management Of An Elderly Man With Undiagnosed Hemophilia B Undergoing a Complex Neurosurgery

Hemophilia B, an X-linked recessive deficiency of factor IX, is present in 1 in 25,000 to 30,000 male births. Hemophilia B patients exhibit a range of clinical severity that correlates with factor levels and can be mild (&gt;5%), moderate (1 to 5%), or severe (&lt;1%). Severe hemophilia B typically presents with spontaneous hemorrhage before age 2. Patients with mild-to-moderate disease are more likely to present later in childhood or teenage years with median age of diagnosis of 11.5 years. The available guidelines are helpful in guiding perioperative hemostasis for most surgeries, as well as managing bleeding complications including intracranial hemorrhage. Unfortunately, very little prospective data exist to guide elective high risk neurosurgeries. This paucity has resulted in a reluctance to offer these patients desperately needed interventions. We report a unique case of undiagnosed mild hemophilia B that was found incidentally at age 64 during pre-operative workup. Additionally, we describe this patient’s successful peri-operative care. Case A 64 year-old man with intractable Parkinson’s disease was referred to the hematology clinic following a neurosurgical evaluation for deep brain stimulator implantation. His preoperative laboratory studies revealed a prolonged aPTT, and normal PT/INR.Past surgeries included uncomplicated knee arthroscopy and appendectomy. The patient has a life-long history of easy bruising, yet no history of spontaneous or provoked bleeding. There were no immediate family members with known bleeding disorders; however the patient described a history of excessive bleeding in his maternal grandfather. Further laboratory evaluation revealed an aPTT of 45.9 seconds and a factor IX level of 13%. Laboratory results were repeated at a separate institution and a reference laboratory for confirmation. Inhibitor studies were negative.Antiphospholipidantibodies were also negative. PTT 1:1 mixing study shoed full correction. Factor II, VII, X, and XI studies were normal. Given the patient’s laboratory findings and positive family history,he was diagnosed with inherited hemophilia B. In preparation for bilateral sub-thalamic stimulator implantation, a Factor IX replacement protocol was devised to minimize the risk of intracranial hemorrhage. The patient was admitted one day prior to surgery. Factor IX concentrates (AlphaNineâ) were utilized. Factor IX was dosed to achieve a preoperative trough factor level of over 100%. Factor IX maintenance was started promptly and doses to achieve a trough level of 80% to 100% for the next 14 days, then to achieve a trough level of 50% for 7 additional days for a total factor support of 21 days. Peak and trough levels were monitored. The patient had 2 sequential surgeries in order to implant deep brain stimulation electrodes in the left and right sub-thalamic nuclei, respectively. Subsequently, a third surgery was required for implantation of the pulse generator and tunneled extension wires. Following the initial seven days of postoperative therapy, the patient was discharged with daily self-administered factor IX. The three-stage surgical approach was successful and no bleeding events were observed during the peri-operative and follow up period. Family counseling and testing was initiated for male family members. Conclusions Hemophilia is a rare disease and often presents early in life. This unique patient had minimal surgical and traumatic exposure, resulting in a subclinical bleeding disorder that remained undisclosed until advanced age. In fact, this report represents one of the oldest age at presentation of Hemophilia B in literature. Although this rare case benefitted from extensive pre-operative bleeding assessment, we do not advocate changing current guidelines regarding peri-operative risk assessment and evaluation. However, this case highlighted the occasional significance of persistent prolonged aPTT and need for evaluation by a hematologist, especially if high-risk invasive intervention is contemplated. Multidisciplinary care and appropriate factor support for patients with hemophilia can reduce their operative bleeding risk, as we demonstrated in this case. A diagnosis of hemophilia should not preclude elective surgical intervention provided that this is performed at a tertiary center that is equipped with resources and expertise to meet the special needs of this patient population. Disclosures: No relevant conflicts of interest to declare.

The Consult Guys - Perioperative Risk Assessment: Can You Get It Right?

Web ExclusivesSeptember 17, 2013The Consult Guys - Perioperative Risk Assessment: Can You Get It Right?FREEGeno J. Merli, MD, Howard H. Weitz, MDGeno J. Merli, MDSearch for more papers by this author, Howard H. Weitz, MDSearch for more papers by this authorAuthor, Article and Disclosure Informationhttps://doi.org/10.7326/G13-3001 SectionsSupplemental MaterialAboutVisual AbstractAbstract ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail The Consult Guys bring a new perspective to the art and science of medicine with lively discussion and analysis of real-world cases and situations.For more videos from and information on The Consult Guys, visit www.annals.org/ConsultGuys. Comments0 CommentsSign In to Submit A Comment J. Roberto Mendoza, MDFSU/TMH IMRP16 December 2013 Good Very clear, down to earth advice on the evaluation of the surgical patient. Nicholas H.E. Mezitis, MD Ohio University - UMA Diabetes Endocrine Care Center 4 May 2015 Preoperative Assessment Very enjoyable and clear exposition of relevant information on an important topic.A pleasure to watch two master clinicians in educational interaction.Thank you for hosting this series. Andrew R. Rosen, MDElliot Health System, Manchester, NH18 August 2014 peroperative assessment thank you for the update- wonderfully clear and concise. Author, Article and Disclosure InformationAffiliations: Disclosures: Geno J. Merli, MD, reports the following: Research grants/contracts: Bristol-Myers Squibb, Bayer, sanofi-aventis; Consultancies: Bristol-Myers Squibb, Bayer, sanofi-aventis. Howard H. Weitz, MD, reports that he has no financial relationships or interests to disclose. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics September 17, 2013Volume 159, Issue 6Page: CG1 ePublished: 17 September 2013 Issue Published: September 17, 2013 CopyrightCopyright © 2013 by American College of Physicians. All Rights Reserved.Loading ...

Risco cirúrgico para cirurgias não cardíacas: aspectos práticos

Revista HUPE, Rio de Janeiro, 2013;12(Supl 1):110-117 doi:10.12957/rhupe.2013.7089 Um frequente motivo de consulta ao cardiologista e ao clínico geral é a avaliação de risco perioperatório em pacientes candidatos a intervenções cirúrgicas não cardíacas. Em última análise, a consulta pré-operatória tem como objetivo identificar e, quando indicado, sugerir intervenções em condições clínicas que possam interferir no resultado da cirurgia. Entretanto, estudos sugerem que essas orientações nem sempre são seguidas pelos consultores, resultando em relatórios incompletos ou meramente burocráticos. A estratificação correta do risco de desenvolver uma complicação cardíaca no período perioperatório permite à equipe médica tomar decisões que contemplam todos os riscos envolvidos, incluído o da doença de base, e buscar as melhores estratégias de tratamento. Nos últimos anos, novas diretrizes têm sugerido uma abordagem escalonada na avaliação do risco cardiológico perioperatório. Tal abordagem leva em consideração o risco inerente ao procedimento proposto, o risco associado à condição cardíaca do paciente e aspectos relativos à doença a ser tratada. Desse modo, busca-se determinar com precisão aqueles pacientes cardiopatas que devem ser tratados antes da cirurgia e quais intervenções realmente interferem no resultado cirúrgico. A presente revisão visa oferecer uma visão sucinta do problema e apontar um modelo prático de avaliação pré-operatória com base nas melhores evidências disponíveis. Algumas situações clínicas específicas comuns em cardiologia também serão comentadas, como forma de auxiliar nas tomadas de decisão. Descritores: Endocardite; Valva cardíaca; Ecocardiograma; Antibiótico.

Cirrhosis as a Moderator of Outcomes in Coronary Artery Bypass Grafting and Off-Pump Coronary Artery Bypass Operations: A 12-Year Population-Based Study

Cirrhosis substantially affects morbidity and mortality in patients who undergo complex surgical procedures. However, cirrhosis is not included as a parameter in standardized perioperative cardiac risk assessment models. We sought to identify the impact of cirrhosis on coronary artery bypass grafting (CABG) and off-pump CABG (OPCAB) outcomes. Using the 1998 to 2009 Nationwide Inpatient Sample databases, we identified 3,046,709 patients who underwent CABG procedures, 744,636 (24.4%) of which were OPCAB; 6,448 (0.3%) had cirrhosis. Using hierarchical multivariable regression models, we analyzed the impact of cirrhosis on in-hospital outcomes: mortality, morbidity, length of stay, hospital charges, and disposition. Severity of liver dysfunction was assessed by the Deyo-Charlson comorbidity index. In the overall CABG group, cirrhosis was independently associated with increased mortality (adjusted odds ratio [AOR] 6.9, 95% confidence interval [CI] 2.8 to 17), morbidity (AOR 1.6, 95% CI 1.3 to 2.0), length of stay (+1.2 days; p < 0.001), and hospital charges (+$22,491; p < 0.001). The prevalence of cirrhosis in the OPCAB group was 0.3% (n= 2,246); the OPCAB subgroup analysis revealed that the presence of cirrhosis did not affect mortality or morbidity unless there was severe liver dysfunction (mortality AOR 5.1, 95% CI 3.7 to 6.9; morbidity AOR 2.1, 95% CI 1.6 to 2.4). However, in the on-pump CABG patients, cirrhosis was associated with increased mortality and morbidity regardless of the severity of liver dysfunction. The impact of cirrhosis on perioperative outcomes and health care costs is significant; CABG should be performed on carefully selected cirrhotic patients and, whenever possible, without the use of cardiopulmonary bypass.

Increased costs of perioperative risk assessment for thyroid surgery in elderly people (over 80 years) presenting with benign disease

Evaluate how surgical treatment of benign thyroid disease in elderly people is prone to induce an increase of costs in the next future due to the aging process of the population. A retrospective analysis has been performed on a total of 116 patients operated between January 2007 and September 2011, divided in a group of 58 patients aged over 80 years (Group A) and 58 patients younger than 80 years (Group B). The analyzed data included age, preoperative diagnosis, severe co-morbidities, procedures other than standard needed to evaluate anaesthesiological risk, postoperative hospital stay, complications, duration of postoperative intensive care monitoring, pathologic characteristics, and costs of anaesthesiological risk assessment. Statistical analysis of collected data showed that the costs related to perioperative risk assessment (p value < 0.001) and the duration of hospital stay (p value < 0.001) were higher in Group A than in Group B. Instead, surgery-related complications were not statistically different. Despite feasibility and safety of modern surgical techniques, indications for surgery in elderly patients affected by benign thyroid disease should be reserved mainly for those patients with severe medical necessity.

The Comprehensive Risk Assessment for Bypass (CRAB) facilitates efficient perioperative risk assessment for patients with critical limb ischemia

Specific perioperative risk assessment models have been developed for bariatric, pancreatic, and colorectal surgery. A similar instrument, specific for patients with critical limb ischemia (CLI), could improve patient-centered clinical decision making. We describe a novel tool to predict 30-day major morbidity and mortality (M&M) after bypass surgery for CLI. Data for 4985 individuals from the 2007 to 2009 National Surgical Quality Improvement Program were used to develop and internally validate the model. Outcome measures included mortality, major morbidity, and a composite end point (M&M). M&M included mortality and the most severe postoperative morbidities that were highly associated with death (eg, sepsis and major cardiopulmonary complications). More than 30 preoperative factors were tested for association with 30-day mortality, major morbidity, and M&M. Significant predictors in multivariate models were assigned integer values (points), which were added to calculate a patient's Comprehensive Risk Assessment For Bypass (CRAB) score. Performance was assessed (C-index) across all outcome measures and compared with other general tools (American Society of Anesthesiologists class, Surgical Risk Scale) and existing CLI-specific survival prediction models (Finnvasc score, Edifoligide for the Prevention of Infrainguinal Vein Graft Failure [PREVENT III] score) on a distinct validation sample (n = 1620). In the derivation data set (n = 3275), the 30-day mortality rate was 2.9%. The rate of any major morbidity was 19.1%. The composite end point M&M occurred in 10.1%. Significant predictors of M&M by multivariate analysis included age >75 years, prior amputation or revascularization, tissue loss, dialysis dependence, severe cardiac disease, emergency operation, and functional dependence. Applied to a distinct validation sample of 1620 patients, higher CRAB scores were significantly associated with higher rates of mortality, all major morbidities, and M&M (P < .0001). Comparison with other models by assessment of area under the receiver-operating characteristic curve revealed the CRAB was a more accurate predictor of mortality, all major morbidity, and M&M. The CRAB is a CLI-specific, risk assessment instrument derived from multi-institutional American College of Surgeons-National Surgical Quality Improvement Program surgical outcomes data that out-performs existing prognostic risk indices in the prediction of clinically significant adverse events after bypass surgery. Use of the CRAB as a risk assessment tool provides an evidence basis for patient-centered clinical decision making and may have a role in identifying patients at higher risk for surgical revascularization in whom an endovascular approach is preferable.

Clinical Use of Ultrasensitive Cardiac Troponin I Assay in Intermediate- and High-Risk Surgery Patients

Background. Cardiac troponin levels have been reported to add value in the detection of cardiovascular complications in noncardiac surgery. A sensitive cardiac troponin I (cTnI) assay could provide more accurate prognostic information. Methods. This study prospectively enrolled 142 patients with at least one Revised Cardiac Risk Index risk factor who underwent noncardiac surgery. cTnI levels were measured postoperatively. Short-term cardiac outcome predictors were evaluated. Results. cTnI elevation was observed in 47 patients, among whom 14 were diagnosed as having myocardial infarction (MI). After 30 days, 16 patients had major adverse cardiac events (MACE). Excluding patients with a final diagnosis of MI, predictors of cTnI elevation included dialysis, history of heart failure, transoperative major bleeding, and elevated levels of pre- and postoperative N-terminal pro-B-type natriuretic peptide (NT-proBNP). Maximal cTnI values showed the highest sensitivity (94%), specificity (75%), and overall accuracy (AUC 0.89; 95% CI 0.80–0.98) for postoperative MACE. Postoperative cTnI peak level (OR 9.4; 95% CI 2.3–39.2) and a preoperative NT-proBNP level ≥917 pg/mL (OR 3.47; 95% CI 1.05–11.6) were independent risk factors for MACE. Conclusions. cTnI was shown to be an independent prognostic factor for cardiac outcomes and should be considered as a component of perioperative risk assessment.

Obstructive Sleep Apnea and Perioperative Complications

Obstructive sleep apnea (OSA) is prevalent in a significant proportion of surgical patients, although most of these patients are undiagnosed. Interest into OSA as an independent risk factor for adverse perioperative outcomes is fairly recent. Although the specific mechanisms of adverse outcomes are yet unclear, specialty bodies have recognized the challenges and provided expert guidance on the perioperative risk assessment and management of these complex patients. This article reviews the key putative mechanisms for adverse outcomes and provides an overview of the effectiveness of risk-modification strategies.

Perioperative Risk Assessment in Robotic General Surgery

To assess factors associated with morbidity and mortality following the use of robotics in general surgery. Case series. University of Illinois at Chicago. Eight hundred eighty-four consecutive patients who underwent a robotic procedure in our institution between April 2007 and July 2010. Perioperative morbidity and mortality. During the study period, 884 patients underwent a robotic procedure. The conversion rate was 2%, the mortality rate was 0.5%, and the overall postoperative morbidity rate was 16.7%. The reoperation rate was 2.4%. Mean length of stay was 4.5 days (range, 0.2-113 days). In univariate analysis, several factors were associated with increased morbidity and included either patient-related (cardiovascular and renal comorbidities, American Society of Anesthesiologists score ≥ 3, body mass index [calculated as weight in kilograms divided by height in meters squared] <30, age ≥ 70 years, and malignant disease) or procedure-related (blood loss ≥ 500 mL, transfusion, multiquadrant operation, and advanced procedure) factors. In multivariate analysis, advanced procedure, multiquadrant surgery, malignant disease, body mass index of less than 30, hypertension, and transfusion were factors significantly associated with a higher risk for complications. American Society of Anesthesiologists score of 3 or greater, age 70 years or older, cardiovascular comorbidity, and blood loss of 500 mL or more were also associated with increased risk for mortality. Use of the robotic approach for general surgery can be achieved safely with low morbidity and mortality. Several risk factors have been identified as independent causes for higher morbidity and mortality. These can be used to identify patients at risk before and during the surgery and, in the future, to develop a scoring system for the use of robotic general surgery

A look into Lee's score: peri-operative cardiovascular risk assessment in non-cardiac surgeries—usefulness of revised cardiac risk index

ObjectiveThe revised cardiac risk index (RCRI/Lee's score) was designed for peri-operative risk assessment before elective major non-cardiac surgeries. Through this article, we report the usefulness of RCRI in our daily practice, while evaluating patients undergoing surgeries of varying risk. MethodsOnly referred patients, aged ≥ 40 years, were included. Risk stratification was done using RCRI scoring system. Patients were categorised into 4 classes depending on 0, 1, 2, and ≥3 risk predictors (risk predictors were high-risk surgery, history of ischaemic heart disease (IHD), diabetes on insulin, history of stroke (cerebrovascular accident [CVA]), history of congestive heart failure (CHF) and serum creatinine of >2 mg%). Electrocardiograms (ECG) were done in all patients, while troponin I in intermediate and high-risk patients, and in others if symptomatic. Perioperative cardiovascular events were managed appropriately. ResultsOf the 920 patients included, only 853 patients were analysed as 67 patients were not operated upon. The mean age was 59 ± 11years and 46% of the patients were women. Two hundred and ninety-two underwent high-risk surgeries, 97 patients had history of IHD, 89 had history of CHF, 36 gave history of CVA, 269 patients were diabetics on insulin and 68 had serum creatinine >2 mg%. Number of patients in Lee's classes I, II, III, and IV were 311, 347, 150, and 52, respectively. 26 out of 853 patients had peri-operative events. Of the six variables in RCRI, only history of IHD was an independent predictor of events. Event rates increased as the RCRI class increased, i.e. 1.7%, 2.0%, 6.7%, and 7.7% for classes I–IV, respectively. Age >70 years, poor general medical condition, emergency surgery and left bundle branch block (LBBB) on ECG, were significantly associated with peri-operative events. ConclusionThe RCRI is a useful tool in pre-operative risk stratification. It should perhaps be further updated to improve its predictive accuracy.

Does an Objective System-Based Approach Improve Assessment of Perioperative Risk in Children? A Preliminary Evaluation of the ‘NARCO’

Malviya, S.; Voepel-Lewis, T.; Chiravuri, S.D.; Gibbons, K.; Chimbira, W.T.; Nafiu, O.O.; Reynolds, P.I.; Tait, A.R. Author Information

Stratifying the Risk of Venous Thromboembolism in Otolaryngology

The consequences of perioperative venous thromboembolism (VTE) are devastating; identifying patients at risk is an essential step in reducing morbidity and mortality. The utility of perioperative VTE risk assessment in otolaryngology is unknown. This study was designed to risk-stratify a diverse population of otolaryngology patients for VTE events. Retrospective cohort study. Single-institution academic tertiary care medical center. Adult patients presenting for otolaryngologic surgery requiring hospital admission from 2003 to 2010 who did not receive VTE chemoprophylaxis were included. The Caprini risk assessment was retrospectively scored via a validated method of electronic chart abstraction. Primary study variables were Caprini risk scores and the incidence of perioperative venous thromboembolic outcomes. A total of 2016 patients were identified. The overall 30-day rate of VTE was 1.3%. The incidence of VTE in patients with a Caprini risk score of 6 or less was 0.5%. For patients with scores of 7 or 8, the incidence was 2.4%. Patients with a Caprini risk score greater than 8 had an 18.3% incidence of VTE and were significantly more likely to develop a VTE when compared to patients with a Caprini risk score less than 8 (P < .001). The mean risk score for patients with VTE (7.4) was significantly higher than the risk score for patients without VTE (4.8) (P < .001). The Caprini risk assessment model effectively risk-stratifies otolaryngology patients for 30-day VTE events and allows otolaryngologists to identify patient subgroups who have a higher risk of VTE in the absence of chemoprophylaxis.

602 The development of a peri-operative risk assessment model for post-operative nausea and vomiting in the Cardiac Surgery ICU Population

602 The development of a peri-operative risk assessment model for post-operative nausea and vomiting in the Cardiac Surgery ICU Population

Risks and Benefits of DVT/PE Prophylaxis in Otolaryngology

Objective: The consequences of perioperative venous thromboembolism (VTE) can be devastating. This study is designed to 1) correlate the incidence of VTE with perioperative risk assessment, 2) determine whether VTE prophylaxis effectively decreases the risk of perioperative VTE, and 3) assess if VTE prophylaxis increases bleeding complications in otolaryngology. Method: A retrospective case-control study was conducted at a tertiary care medical center among adults presenting for otolaryngologic surgery from 2003 to 2010 (n = 3498). Patients treated before the implementation of guideline-based VTE prophylaxis protocols were compared to patients treated after implementation. Primary outcome variables were Caprini risk level, perioperative VTE, and bleeding complications. Results: The odds of a VTE increased 1.435 times with each level increase in the Caprini VTE risk level ( P = .048). The VTE rate after implementation of prophylactic protocols was significantly lower than prior to implementation (OR 0.286, P = .005). However, the type of VTE prophylaxis had no significant effect on the likelihood of developing a VTE. The likelihood of a bleeding complication was not significantly different before and after implementation. The odds of a bleeding complication increased for patients receiving twice daily enoxaparin (OR 4.546, P = .032) or a treatment (rather than prophylactic) dose of anticoagulant (OR 3.546, P &lt; .001). Conclusion: Perioperative VTE risk stratification based on Caprini risk assessment in otolaryngology is effective. The odds of VTE decreased after the implementation of guideline-directed VTE prophylaxis. Although perioperative bleeding complications did not increase after the implementation of VTE prophylaxis protocols, therapeutic anticoagulation is associated with a higher incidence of bleeding complications.

Using Procedural Codes to Supplement Risk Adjustment: A Nonparametric Learning Approach

The American College of Surgeons National Surgical Quality Improvement Program collects information related to procedures in the form of the work relative value unit (RVU) and current procedural terminology (CPT) code. We propose and evaluate a fully automated nonparametric learning approach that maps individual CPT codes to perioperative risk. National Surgical Quality Improvement Program participant use file data for 2005-2006 were used to develop 2 separate support vector machines (SVMs) to learn the relationship between CPT codes and 30-day mortality or morbidity. SVM parameters were determined using cross-validation. SVMs were evaluated on participant use file data for 2007 and 2008. Areas under the receiver operating characteristic curve (AUROCs) were each compared with the respective AUROCs for work RVU and for standard CPT categories. We then compared the AUROCs for multivariable models, including preoperative variables, RVU, and CPT categories, with and without the SVM operation scores. SVM operation scores had AUROCs between 0.798 and 0.822 for mortality and between 0.745 and 0.758 for morbidity on the participant use file used for both training (2005-2006) and testing (2007 and 2008). This was consistently higher than the AUROCs for both RVU and standard CPT categories (p < 0.001). AUROCs of multivariable models were higher for 30-day mortality and morbidity when SVM operation scores were included. This difference was not significant for mortality but statistically significant, although small, for morbidity. Nonparametric methods from artificial intelligence can translate CPT codes to aid in the assessment of perioperative risk. This approach is fully automated and can complement the use of work RVU or traditional CPT categories in multivariable risk adjustment models like the National Surgical Quality Improvement Program.

One-year follow-up of patients undergoing elective cardiac surgery assessed with the Comprehensive Assessment of Frailty test and its simplified form

Assessment of perioperative risk of elderly patients in cardiac surgery is demanding. Most of the commonly used cardiac surgery risk scores over-or underestimate individual risk. Therefore, we recently developed a 'frailty score', the comprehensive assessment of frailty (CAF) score that showed a good prediction of 30-day mortality. The aim of the study was to evaluate the ability of the new score predicting one-year outcome. CAF was preoperatively applied to 400 patients ≥ 74 years that were admitted to cardiac surgery between September 2008 and January 2010. For 213 of these patients one-year follow-up was assessed by telephone interview until April 2010. One hundred and ten male and 103 female patients were included. Twenty-five percent underwent isolated coronary revascularization, 35% isolated valve procedures and 26% underwent combined procedures. One-year mortality was 12.2%. Patients who died within one year had a median frailty score of 16 [5;33] compared to 11 [3;33] to the one-year survivors (P=0.001). A new, easily applicable score ('Frailty predicts death One yeaR after Elective Cardiac Surgery Test') was built out of the basic score and showed a promising ability to predict one-year mortality. CAF is a new additional tool to assess prognosis of elderly patients before cardiac surgical interventions. The 'CAF' score facilitates prediction of mid-term outcome of high-risk elderly patients.