Surgery-specific Risk Research Articles

The pharmacist's role in optimizing medication management before, during, and after minimally invasive and bariatric surgery.

In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. Minimally invasive surgery (MIS) with integrated enhanced recovery pathways (ERPs) helps reduce length of stay and improve surgical outcomes. As these procedures have become more prevalent over time, pharmacists are in key positions to manage medications in the perioperative space to help optimize transitions of care and reduce safety events. Here we identify several clinical areas across phases of care for these procedures in which the knowledge and guidance of pharmacists, as members of the interprofessional team, are paramount. Perioperative pharmacy expertise is often required for MIS procedures in the areas of acid suppression, antithrombotic management, blood glucose control, drug formulation, immunosuppressant optimization, pain mitigation, and postoperative nausea and vomiting prevention and treatment. For each MIS procedure, pharmacists should identify and consider diet and anatomical changes as well as patient- and surgery-specific risk factors. Pharmacists can then utilize their knowledge of the pharmacokinetics and pharmacodynamics of individual medications along with evidence-based medicine to recommend selection of appropriate agents. Pharmacist contributions to perioperative medication management for MIS procedures can improve care as surgical patients navigate transitions through the perioperative setting. Pharmacists can further incorporate medication expertise through development and implementation of institutional MIS protocols within the context of ERPs. As such, any pharmacist should feel empowered to aid in the care of surgical patients.

Risk Factors for the Development of Persistent Scaphoid Non-Union After Surgery for an Established Non-Union.

Between 2014 and 2020, candidates for scaphoid non-union (SNU) surgery were enrolled in a prospective randomized trial (Scaphoid Nonunion and Low Intensity Pulsed Ultrasound [SNAPU] trial) evaluating the effect of low-intensity pulsed ultrasound on postoperative scaphoid healing. At trial completion, 114/134 (85%) of these patients went on to union, and 20/134 (15%) went on to persistent SNU (PSNU). The purpose of this study was to use this prospectively gathered data to identify patient-, fracture-, and surgery-specific risk factors that may be predictive of PSNU in patients who undergo surgery for SNU. Data were extracted from the SNAPU trial database. The inclusion and exclusion criteria of this study were the same as that of the SNAPU trial. Nineteen patient-, fracture-, and surgery-specific risk factors were determined a priori. A stepwise multivariable logistic regression model was used to identify independent risk factors for PSNU. Three risk factors were found to be independently significant predictors of PSNU: age at the time of surgery, dominant hand injury, and previous surgery on the affected scaphoid. With every decade of a patient's life, dominant hand injury, and previous scaphoid surgery, the odds of union are reduced by 1.72 times, 7.35 times, and 4.24 times, respectively. We identified three independent risk factors for PSNU: age at SNU surgery, dominant hand injury, and previous surgery on the affected scaphoid. The findings of this study are significant and may contribute to shared decision-making and prognostication between the patient, surgeon, and affiliated members of their care team.

Intraoperative Hemodynamic Monitoring and Management

Postoperative deaths are a consequence of postoperative complications - including acute kidney injury and myocardial injury. Postoperative complications are associated with non-modifiable patient-specific risk factors (i.e., age, medical history), but also with potentially modifiable risk factors - including intraoperative hypotension and compromised intraoperative blood flow. Based on patient- and surgery-specific risk factors, the intraoperative hemodynamic monitoring strategy needs to be selected. Intraoperative hypotension is associated with postoperative organ failure and should thus be avoided. To optimize intraoperative hemodynamics, cardiac output-guided hemodynamic management has been proposed. Cardiac output-guided hemodynamic management aims at optimizing oxygen delivery using fluids, vasopressors, and inotropes. Cardiac output-guided hemodynamic management has been shown to reduce postoperative complications compared to routine hemodynamic management in high-risk patients having major surgery.

Risks and Outcomes of Perioperative Pulmonary Embolism in Major Surgeries: A Population-Based Study

Perioperative pulmonary embolism (PE) is a significant cardiovascular complication in many surgeries. This study aimed to investigate the risks and outcomes of perioperative PE in major surgery. Discharge records of the Nationwide Readmission Database from 2010 to 2015 were extracted and analyzed. Length of stay, charges, death, and 30-day hospital readmission rate were compared for patients with and without perioperative PE. In addition, surgery-specific risk factors and therapies associated with PE were explored in a multivariable model. A total of 12,376,153 hospitalizations for major surgeries were involved, and perioperative PE occurred in 22,676 hospitalizations (0.18%). The length of stay, charges, rate of death, and 30-day hospital readmission were higher in patients with perioperative PE than in those without perioperative PE. Respiratory (odds ratios [OR], 2.09; 95% CI, 1.89-2.3), cardiovascular (OR, 1.62; 95% CI, 1.51-1.73), and musculoskeletal (OR, 1.22; 95% CI, 1.1-1.29) surgeries were risk factors for the occurrence of perioperative PE. In patients with perioperative PE, respiratory surgery was a risk factor for death (OR, 1.48; 95% CI, 1.10-2.00), whereas gynecologic/obstetric surgery was a protective factor for 30-day readmission (OR, 0.30; 95% CI, 0.10-0.88). Regarding therapy for perioperative PE, thrombolytic therapy (OR, 1.74; 95% CI, 1.26-2.42) and embolectomy (OR, 3.60; 95% CI, 2.35-5.51) were risk factors for death. Respiratory, cardiovascular, and musculoskeletal surgeries were risk factors for the occurrence of perioperative PE and death. Future research on precise models to predict PE in major surgeries is needed for appropriate interventions to improve outcomes of perioperative PE.

Derivation, Validation, Sustained Performance, and Clinical Impact of an Electronic Medical Record-Based Perioperative Delirium Risk Stratification Tool.

Postoperative delirium is an important problem for surgical inpatients and was the target of a multidisciplinary quality improvement project at our institution. We developed and tested a semiautomated delirium risk stratification instrument, Age, WORLD backwards, Orientation, iLlness severity, Surgery-specific risk (AWOL-S), in 3 independent cohorts from our tertiary care hospital and describe its performance characteristics and impact on clinical care. The risk stratification instrument was derived with elective surgical patients who were admitted at least overnight and received at least 1 postoperative delirium screen (Nursing Delirium Screening Scale [NuDESC] or Confusion Assessment Method for the Intensive Care Unit [CAM-ICU]) and preoperative cognitive screening tests (orientation to place and ability to spell WORLD backward). Using data pragmatically collected between December 7, 2016, and June 15, 2017, we derived a logistic regression model predicting probability of delirium in the first 7 postoperative hospital days. A priori predictors included age, cognitive screening, illness severity or American Society of Anesthesiologists physical status, and surgical delirium risk. We applied model odds ratios to 2 subsequent cohorts ("validation" and "sustained performance") and assessed performance using area under the receiver operator characteristic curves (AUC-ROC). A post hoc sensitivity analysis assessed performance in emergency and preadmitted patients. Finally, we retrospectively evaluated the use of benzodiazepines and anticholinergic medications in patients who screened at high risk for delirium. The logistic regression model used to derive odds ratios for the risk prediction tool included 2091 patients. Model AUC-ROC was 0.71 (0.67-0.75), compared with 0.65 (0.58-0.72) in the validation (n = 908) and 0.75 (0.71-0.78) in the sustained performance (n = 3168) cohorts. Sensitivity was approximately 75% in the derivation and sustained performance cohorts; specificity was approximately 59%. The AUC-ROC for emergency and preadmitted patients was 0.71 (0.67-0.75; n = 1301). After AWOL-S was implemented clinically, patients at high risk for delirium (n = 3630) had 21% (3%-36%) lower relative risk of receiving an anticholinergic medication perioperatively after controlling for secular trends. The AWOL-S delirium risk stratification tool has moderate accuracy for delirium prediction in a cohort of elective surgical patients, and performance is largely unchanged in emergent/preadmitted surgical patients. Using AWOL-S risk stratification as a part of a multidisciplinary delirium reduction intervention was associated with significantly lower rates of perioperative anticholinergic but not benzodiazepine, medications in those at high risk for delirium. AWOL-S offers a feasible starting point for electronic medical record-based postoperative delirium risk stratification and may serve as a useful paradigm for other institutions.

Venous Thromboembolism in Patients with Inflammatory Bowel Disease: The Role of Pharmacological Therapy and Surgery.

Patients with inflammatory bowel disease (IBD) have an increased risk of venous thromboembolism (VTE). Alongside the traditional acquired and genetic risk factors for VTE, patients with IBD have pathogenic and clinical peculiarities that are responsible for the increased number of thromboembolic events occurring during their life. A relevant role in modifying this risk in a pro or antithrombotic manner is played by pharmacological therapies and surgery. The availability of several biological agents and small-molecule drugs with different mechanisms of action allows us to also tailor the treatment based on the individual prothrombotic risk to reduce the occurrence of VTE. Available review articles did not provide sufficient and updated knowledge on this topic. Therefore, we assessed the role of each single treatment, including surgery, in modifying the risk of VTE in patients with IBD to provide physicians with recommendations to minimize VTE occurrence. We found that the use of steroids, particularly if prolonged, increased VTE risk, whereas the use of infliximab seemed to reduce such risk. The data relating to the hypothesized prothrombotic risk of tofacitinib were insufficient to draw definitive conclusions. Moreover, surgery has an increased prothrombotic risk. Therefore, implementing measures to prevent VTE, not only with pharmacological prophylaxis but also by reducing patient- and surgery-specific risk factors, is necessary. Our findings confirm the importance of the knowledge of the effect of each single drug or surgery on the overall VTE risk in patients with IBD, even if further data, particularly regarding newer drugs, are needed.

Impact of a risk-stratified thromboprophylaxis protocol on the incidence of postoperative venous thromboembolism and bleeding.

Efforts to reduce postoperative venous thromboembolism are challenging due to heterogeneity in thromboprophylaxis practice. As a result, a 'one-size-fits-all' approach that accounts for surgery-specific risk, but fails to account for patient-level variation, is often adopted by healthcare networks. Updated clinical practice guidelines have advocated an individualised risk-stratified approach that balances the risk:benefit ratio associated with thromboprophylaxis; however, there are limited data confirming effectiveness of these recommendations on the incidence of postoperative venous thromboembolism and bleeding. We developed the surgical-thrombo-embolism-prevention protocol, a novel risk-stratified algorithm that classified patients into low-, intermediate-, and high-risk profiles according to surgical procedure and patient baseline medical risk. Expert-endorsed risk-specific thromboprophylaxis strategies were then applied. A staged quality improvement program was developed to implement the protocol. We postulated that compliance with the protocol would reduce postoperative venous thromboembolism rates without increasing the incidence of postoperative bleeding. Between June 2013 and March 2018, we evaluated the efficacy, safety and sustainability of this risk-stratified approach in 24,953 surgical admissions at a dedicated cancer centre. By final implementation, program compliance was 91%. Postoperative venous thromboembolism rates reduced from 3.1 per 1000 surgical admissions to 0.6 per 1000 surgical admissions (relative risk reduction 79%; p < 0.005). Postoperative bleeding rates also declined from 10.0 per 1000 surgical admissions to 6.3 per 1000 surgical admissions (relative risk reduction 37%; p = 0.02). Sustained improvement was evident more than 3 years after implementation. Implementation of the surgical-thrombo-embolism-prevention protocol significantly reduced the incidence of postoperative venous thromboembolism supporting its validation at other institutions.

Extended thromboprophylaxis following colorectal surgery in patients with inflammatory bowel disease: a comprehensive systematic clinical review.

Patients with inflammatory bowel disease (IBD) are at increased risk of postoperative venous thromboembolism (VTE) following major abdominal surgery. The pathogenesis is multifactorial and not fully understood. A combination of pathophysiology, patient and surgical risk factors increase the risk of postoperative VTE in these patients. Despite being at increased risk, IBD patients are not regularly prescribed extended pharmacological thromboprophylaxis following colorectal surgery. Currently, there is a paucity of evidence-based guidelines. Thus, the aim of this review is to evaluate the role of extended pharmacological thromboprophylaxis in IBD patients undergoing colorectal surgery. A search of Ovid Medline, EMBASE and PubMed databases was performed. A qualitative analysis was performed using 10 clinical questions developed by colorectal surgeons and a thrombosis haematologist. The Newcastle-Ottawa Scale was utilized to assess the quality of evidence. A total of 1229 studies were identified, 38 of which met the final inclusion criteria (37 retrospective, one case-control). Rates of postoperative VTE ranged between 0.6% and 8.9%. Patient-specific risk factors for postoperative VTE included ulcerative colitis, increased age and obesity. Surgery-specific risk factors for postoperative VTE included open surgery, emergent surgery and ileostomy creation. Patients with IBD were more frequently at increased risk in the included studies for postoperative VTE than patients with colorectal cancer. The risk of bias assessment demonstrated low risk of bias in patient selection and comparability, with variable risk of bias in reported outcomes. There is a lack of evidence regarding the use of extended pharmacological thromboprophylaxis in patients with IBD following colorectal surgery. As these patients are at heightened risk of postoperative VTE, future study and consideration of the use of extended pharmacological thromboprophylaxis is warranted.

Clinical- and surgery-specific risk factors for post-operative sepsis: a systematic review and meta-analysis of over 30 million patients.

Post-operative sepsis is a severe complication of surgery, which often worsens the clinical outcomes. While several risk factors have been identified, the importance of others remains uncertain. This systematic review and meta-analysis aimed to determine patient and surgery-related risk factors for post-operative sepsis. We reviewed Medline, the Web of Science, and the Cochrane library, systematically, for articles describing risk factors for sepsis. The role of eligible risk factors was investigated using a random-effects model, while analyzing univariate and multivariate data separately. Among 193 pro- and retrospective articles, comprising over 30 million patients, 38 eligible risk factors were selected for this meta-analysis. The patient-related risk factors associated with post-operative sepsis included male gender (odds ratio, OR 1.41), pre-existing heart failure (OR 2.53), diabetes (OR 1.41), and chronic kidney disease (OR 1.26). The surgery-related risk factors identified included emergency surgery (OR 3.38), peri-operative blood transfusion (OR 1.90), inpatient hospital stay (OR 2.31), and open surgery (OR 1.80). The adjusted overall incidence of surgical sepsis was 1.84%. In conclusion, multiple-patient and surgery-related risk factors are associated with the development of post-operative sepsis. Recognizing these risk factors could assist in the pre-operative identification of patients at risk of post-operative sepsis.

Epidemiology of Iatrogenic Vertebral Artery Injury in Cervical Spine Surgery: 21 Multicenter Studies

The overall incidence of iatrogenic vertebral artery injury (IVAI) in cervical spine surgeries (CSSs) is reported to be 0.07%-1.4%. Although IVAI occurred during C1-2 fusion, there is no accurate information regarding the surgery-specific risk of IVAI. This study aimed to stratify incidence of IVAI by surgical method and evaluate the correlation between IVAI and its sequelae. This retrospective, multicenter study involved clinical and radiologic evaluations for IVAI. All CSSs performed between 2012 and 2016 were included; neck mass excision and pain intervention were excluded. Patient characteristics, diagnosis, surgical technique, complications, and presence of IVAI were collected. In IVAI cases, technique details, characteristics, and sequelae were investigated. This study included 14,722 patients with 15,582 CSSs in 21 centers. IVAIs were identified in 13 (0.08%) patients. Surgery-specific incidence of IVAI was 1.35% in cases involving C1-2 posterior fixation and 0.20% in cases involving C3-6 posterior fixation. Common injury mechanisms were screw-in (31%) and high-speed drilling (23%). Screw-related IVAI occurred in 9 (69%) patients, and IVAI of the C1 lateral mass and C2 pedicle screws occurred in 4 and 3 patients, respectively. Of 13 cases of IVAI, 3 (23%) involved cerebellar or stem infarction; the infarction had no substantial correlation with injury grade or dominancy. Overall incidence of IVAI in CSSs was 0.08%. C1-2 posterior fixation had the highest incidence of IVAI (1.35%). Although clinical results of IVAI can be highly variable, controlling risk factors of IVAI is important.

ASO Author Reflections: Addressing Surgery-Specific Risk Factors Influencing Time to Chemotherapy in Breast Cancer.

ASO Author Reflections: Addressing Surgery-Specific Risk Factors Influencing Time to Chemotherapy in Breast Cancer.

Risk Factors for Perioperative Blood Transfusions in Adult Spinal Deformity Surgery

Adult spinal deformity (ASD) surgery is associated with a high rate of perioperative blood transfusions, and it is important to understand the risk factors for perioperative blood transfusions to implement strategies to reduce transfusions. The aim of this study was to identify independent risk factors of perioperative blood transfusions in patients undergoing surgery for ASD. A retrospective cohort study was performed using the American College of Surgeons National Surgical Quality Improvement Program database from 2010 to 2014. Adult patients undergoing surgery for ASD were separated into 2 cohorts based on whether they received a perioperative blood transfusion. Univariate and multivariate regression models were used to identify risk factors for blood transfusion. In our cohort of 5805 patients, 27.1% received a blood transfusion. Multivariate regression analysis showed that patient-specific risk factors were age 65 years or older (odds ratio [OR], 1.74; 95% confidence interval [CI], 1.49-2.03; P < 0.001), American Society of Anesthesiologists classification of 3 or greater (OR, 1.18; 95% CI, 1.01-1.37; P= 0.033), cardiac comorbidity (OR, 1.21; 95% CI, 1.03-1.41; P= 0.018) and bleeding disorder (OR, 2.01; 95% CI, 1.10-3.66; P= 0.023). Surgery-specific risk factors were a posterior approach (OR, 4.25; 95% CI, 3.46-5.22; P<0.001), pelvic fixation (OR, 1.73; 95% CI, 1.36-2.20; P<0.001), and osteotomy (OR, 2.08; 95% CI, 1.71-2.51; P < 0.001). Longer operative time was also a risk factor with a duration-dependent effect on the odds of blood transfusion. Recognition of patient- and surgery-specific risk factors for perioperative blood transfusion is important to identify patients who are at high risk and to implement strategies to minimize intraoperative blood loss and decrease healthcare costs.

Role of patient- and surgery-specific risk in receipt of outpatient preoperative testing

ObjectiveTo determine the independent association of patient- and surgery-specific risk with receipt of outpatient preoperative testing. MethodsUsing administrative data from 2010–2013 (Marketscan® Commercial Claims and Encounters), we constructed a retrospective cohort of 678,368 privately-insured, non-elderly US adults who underwent one of ten operations, including one lower-risk and one higher-risk operation from five surgical specialties. Outcomes were receipt of nine outpatient tests in the 30 days before surgery and cost of those tests. Patient-specific risk was based on Revised Cardiac Risk Index (RCRI) and, alternatively, the Charlson Comorbidity Index (CCI). Surgery-specific risk was based on operation (higher- versus lower-risk within each specialty). Multivariable logistic regression models were constructed to measure the independent association of patient- and surgery-specific risk with the receipt of tests. ResultsReceipt of tests ranged from 0.9% (pulmonary function tests) to 46.8% (blood counts), and 65.2% of patients received at least one test. Mean cost per patient for all tests was $124.38. Higher RCRI was strongly associated (Odds Ratio (OR) > 2) with receipt of stress tests and echocardiograms, and more modestly associated [OR < 2] with receipt of most other tests. Undergoing higher-risk operations was strongly associated with receipt of most tests. Results were similar using the CCI for patient-specific risk. ConclusionSurgery-specific risk is strongly associated with receipt of most preoperative tests, which is consistent with preoperative testing protocols based as much or more on the planned operation as on patient-specific risk factors. Whether this pattern of preoperative testing represents optimal care is uncertain.

Surgical Risk Factors for the Delayed Initiation of Adjuvant Chemotherapy in Breast Cancer.

Timely administration of adjuvant chemotherapy for breast cancer is associated with a survival benefit. Specific elements of surgical management may lead to delays initiating chemotherapy, resulting in unfavorable outcomes. The purpose of this study was to determine the correlation between surgical factors and delayed chemotherapy in breast cancer patients. A retrospective analysis of the National Cancer Database was performed. The study cohort consisted of female patients with stage 1-3 breast cancer diagnosed between 2010 and 2014. Initiation of chemotherapy beyond 90days after surgery was defined as delayed. Multivariable logistic regression modeling was performed to establish associations between delayed chemotherapy and clinical and demographic factors of interest. Survival analysis was performed using the Kaplan-Meier estimation and Cox proportional hazards regression to evaluate potential 5-year overall survival disadvantage of delayed initiation of chemotherapy. Of 166,681 women assessed, 4.3% had a delay in the initiation of chemotherapy. Surgery-specific risk factors included unplanned readmission in the postoperative period, lower surgical volume, mastectomy with immediate autologous reconstruction, and positive surgical margins. Adjusted survival analysis showed a survival disadvantage of delayed initiation of chemotherapy (hazard ratio [HR] 1.46; p<0.01). Risk factors for delayed initiation of chemotherapy specific to the surgical process were identified. Delayed initiation of adjuvant chemotherapy was associated with a survival detriment. Efforts should be made to address these surgical management issues and optimize the perioperative process to ensure timely patient treatment.

Cardiac Events after Noncardiac Surgery in Patients Undergoing Preoperative Dobutamine Stress Echocardiography: Findings From the Mayo Poce-DSE Investigators

BackgroundCurrent guidelines support the use of dobutamine stress echocardiography (DSE) prior to noncardiac surgery in higher-risk patients who are unable to perform at least 4 metabolic equivalents of physical activity. We evaluated postoperative outcomes of patients in different operative risk categories after preoperative DSE. MethodsWe collected data from the medical record on 4494 patients from January 1, 2006 to December 31, 2011 who had DSE up to 90 days prior to a noncardiac surgery. Patients were divided into low, intermediate, and high preoperative surgery-specific risk. Baseline demographic data and risk factors were abstracted from the medical record, as were postoperative cardiac events including myocardial infarction, cardiac arrest, and mortality within 30 days after surgery. ResultsThere were 103 cardiac outcomes (2.3%), which included myocardial infarction (n = 57, 1.3%), resuscitated cardiac arrest (n = 26, 0.6%), and all-cause mortality (n = 40, 0.9%). Cardiac event rates were 0.0% (95% confidence interval [CI], 0.0%-3.9%) in the low-surgical-risk group, 2.1% (95% CI, 1.6%-2.5%) in the intermediate-surgical-risk group, and 3.4% (95% CI, 2.0%-4.4%) in the high-risk group. Thirty-day postoperative mortality rates were 0%, 0.9%, and 0.8% for the low-risk, intermediate-risk, and high-risk surgical groups, respectively, and were not statistically different. ConclusionsThese findings demonstrate low cardiac event rates in patients who underwent a DSE prior to noncardiac surgery. The previously accepted construct of low-, intermediate-, and high-risk surgeries based on postoperative events of <1%, 1%-5%, and >5% overestimates the actual risk in contemporary settings.

Comparison of Risk Models at Predicting Outcomes of Isolated Tricuspid Valve Surgery

Aims: Isolated tricuspid valve surgery is considered for patients with severe tricuspid valve disease with symptoms or right ventricular dysfunction, in absence of significant other valve disease. Risk stratification plays an important role for decision-making in cardiac surgery, but has rarely been studied for this high risk cohort. We compared the prognostic utility conventional surgical risk scores for isolated tricuspid valve surgery. Methods: All patients having isolated tricuspid valve surgery during April 2001 to June 2017 at Auckland City Hospital were reviewed. We retrospectively calculated their logistic EuroSCORE, EuroSCORE II and the novel STS tricuspid surgery additive score, and assessed their performance for mortality and morbidities. Results: Amongst 54 patient studied with operative mortality of 11% (6), mean ± standard deviation of risk models were EuroSCORE 7.9 ± 5.2%, EuroSCORE II 3.4 ± 3.2%, STS additive score for mortality 3.8 ± 2.3 and for morbidity 4.6 ± 2.7. None of the scores predicted operative mortality c-statistic (95% confidence interval) of 0.42 (0.22-0.61), 0.58 (0.40-0.77), 0.56 (0.36-0.77) and 0.62 (0.40-0.85) respectively. EuroSCORE II was able to predict long-term mortality 0.74 (0.59-0.89) and acute renal failure 0.68 (0.53-0.83), whereas none of the other scores could detect adverse outcomes. In multivariable analysis, cardiopulmonary bypass time predicted operative mortality, body mass index predicted composite morbidity, and diabetes mellitus predicted long-term mortality. Conclusion: Current surgical risk scores couldn’t predict and underestimated operative mortality after isolated tricuspid surgery, with only the EuroSCORE II predicting some of the adverse outcomes. There is unmet need to developing tricuspid valve surgery-specific risk models with adequate discrimination and good calibration.

How to better identify patients at high risk of postoperative complications?

Preoperative risk assessment and perioperative factors may help identify patients at increased risk of postoperative complications and allow postoperative management strategies that improve patient outcomes. This review summarizes historical and more recent scoring systems for predicting patients with increased morbidity and mortality in the postoperative period. Most prediction scores predict postoperative mortality with, at best, moderate accuracy. Scores that incorporate surgery-specific and intraoperative covariates may improve the accuracy of traditional scores. Traditional risk factors including increased ASA physical status score, emergent surgery, intraoperative blood loss and hemodynamic instability are consistently associated with increased mortality using most scoring systems. Preoperative clinical risk indices and risk calculators estimate surgical risk with moderate accuracy. Surgery-specific risk calculators are helpful in identifying patients at increased risk of 30-day mortality. Particular attention should be paid to intraoperative hemodynamic instability, blood loss, extent of surgical excision and volume of resection.

Value of the oxygenation index during 1-lung ventilation for predicting respiratory complications after thoracic surgery

PurposeThoracic surgery requiring 1-lung ventilation (OLV) is associated with significant postoperative pulmonary complications (PPCs) due to patient- and surgery-specific risk factors. The aim of this study is to determine whether the oxygenation index (OI) (fraction of inspired oxygen × mean airway pressure/partial pressure of oxygen) during OLV predicts the development of PPC. Materials and methodsThe Society of Thoracic Surgeons General Thoracic Surgery Database at the University of Virginia was used to identify all thoracic cases in 2012 to 2014. All subjects requiring OLV and in whom a blood gas was available for analysis were included. Univariate and multivariate analyses were performed to determine whether the OI predicted the development of PPC. ResultsA total of 296 subjects had OLV with a calculable OI during the study period. Composite PPC were identified in 97 (33%) of subjects. In the PPC group, mortality at 30 days was 7.2%, whereas no deaths were identified in the non-PPC group. In both univariate and multivariate analyses, OI was not predictive of PPC analysis (odds ratio [OR], 1.0; 95% confidence interval [CI], 0.9-1.1; P = .8). The only predictors of mortality were forced expiratory volume (OR, 0.98; 95% CI, 0.96-0.99; P = .03) and diffusion capacity of carbon monoxide (OR, 0.98; 95% CI, 0.96-0.99; P = .03). ConclusionThe calculated OI during OLV is not predictive of PPC in our sample. Additional studies in a larger cohort of patients are needed to identify intraoperative ventilation parameters during OLV that can predict the risk of PPC.

The cardiac consult for patients undergoing non-cardiac surgery

### Learning objectives The goal of the preoperative cardiac consultation is to assess the patient’s perioperative risk, to determine the need for additional testing or changes in management and to...

A Systematic Approach to the Preoperative Medical Evaluation of Adults

The number, age, and medical complexity of patients undergoing elective noncardiac surgery is rising worldwide. Internists, family physicians, and midlevel providers asked to perform preoperative medical evaluations. However, lack of consensus has led to wide variation in practice in what is included and addressed in these evaluations, and the efficacy of these assessments has been debated. The intended purpose of the evaluation seems to be universally accepted as aiming to assess and identify risks associated with the patient's comorbid medical conditions and the specific surgical procedure. The goal is to minimize those risks. Herein, we propose a systematic approach to the preoperative medical evaluation based on the best available evidence and expert opinion, with an emphasis on identifying all potentially pertinent patient-and surgery-specific risk factors.