Comparing preoperative fasting and ultrasound-measured intravascular volume status in elective surgery, enhanced recovery patients versus inpatient, urgent surgery patients and the ability of IVC collapsibility to predict post-induction hypotension.

Hypotension following induction of general anaesthesia has been shown to result in increased complications and mortality postoperatively. Patients admitted to the hospital undergoing urgent surgery are often fasted from fluids for significant periods compared to elective patients subject to Enhanced Recovery After Surgery protocols despite guidelines stating that a two-hour fast is sufficient. The aim of this prospective, observational study was to compare fasting times and intravascular volume status between elective surgery patients subject to enhanced recovery protocols and inpatient, urgent surgery patients and to assess differences in the incidence of post-induction hypotension. Fasting data was obtained by questionnaire in the preoperative area in addition to inferior vena cava collapsibility index, a non-invasive measure of intravascular volume. Blood pressure readings and drug administration for the ten minutes following induction were obtained from patients' charts. Inpatients undergoing urgent surgery were fasted significantly longer than enhanced recovery patients and had lower intravascular volume. However, no difference was found in the incidence of post-induction hypotension.

Perioperative Management of Vitamin K Antagonists and Direct Oral Anticoagulants: A Systematic Review and Meta-analysis.

BACKGROUND: The management of patients who are receiving chronic oral anticoagulation therapy and require an elective surgery or an invasive procedure is a common clinical scenario. RESEARCH QUESTION: What is the best available evidence to support the development of American College of Chest Physicians guidelines on the perioperative management of patients who are receiving long-term vitamin K agonist (VKA) or direct oral anticoagulant (DOAC) and require elective surgery or procedures? STUDY DESIGN AND METHODS: A literature search including multiple databases from database inception through July 16, 2020, was performed. Meta-analyses were conducted when appropriate. RESULTS: In patients receiving VKA (warfarin) undergoing elective noncardiac surgery, shorter (< 3 days) VKA interruption is associated with an increased risk of major bleeding. In patients who required VKA interruption, heparin bridging (mostly with low-molecular-weight heparin [LMWH]) was associated with a statistically significant increased risk of major bleed, representing a very low certainty of evidence (COE). Compared with DOAC interruption 1 to 4 days before surgery, continuing DOACs may be associated with higher risk of bleeding demonstrated in some, but not all studies. In patients who needed DOAC interruption, bridging with LMWH may be associated with a statistically significant increased risk of bleeding, representing a low COE. INTERPRETATION: The certainty in the evidence supporting the perioperative management of anticoagulants remains limited. No high-quality evidence exists to support the practice of heparin bridging during the interruption of VKA or DOAC therapy for an elective surgery or procedure, or for the practice of interrupting VKA therapy for minor procedures, including cardiac device implantation, or continuation of a DOAC vs short-term interruption of a DOAC in the perioperative period.

Evaluation of machine learning models as decision aids for anesthesiologists.

Machine Learning (ML) models have been developed to predict perioperative clinical parameters. The objective of this study was to determine if ML models can serve as decision aids to improve anesthesiologists' prediction of peak intraoperative glucose values and postoperative opioid requirements. A web-based tool was used to present actual surgical case and patient information to 10 practicing anesthesiologists. They were asked to predict peak glucose levels and post-operative opioid requirements for 100 surgical patients with and without presenting ML model estimations of peak glucose and opioid requirements. The accuracies of the anesthesiologists' estimates with and without ML estimates as reference were compared. A questionnaire was also sent to the participating anesthesiologists to obtain their feedback on ML decision support. The accuracy of peak glucose level estimates by the anesthesiologists increased from 79.0 ± 13.7% without ML assistance to 84.7 ± 11.5% (< 0.001) when ML estimates were provided as reference. The accuracy of opioid requirement estimates increased from 18% without ML assistance to 42% (p < 0.001) when ML estimates were provided as reference. When ML estimates were provided, predictions of peak glucose improved for 8 out of the 10 anesthesiologists, while predictions of opioid requirements improved for 7 of the 10 anesthesiologists. Feedback questionnaire responses revealed that the anesthesiologist primarily used the ML estimates as reference to modify their clinical judgement. ML models can improve anesthesiologists' estimation of clinical parameters. ML predictions primarily served as reference information that modified an anesthesiologist's clinical estimate.

Perioperative Management of Antiplatelet Therapy: A Systematic Review and Meta-analysis.

Objective: To summarize the available evidence about the perioperative management of patients who are receiving long-term antiplatelet therapy and require elective surgery/procedures. Methods: This systematic review supports the development of the American College of Chest Physicians guideline on the perioperative management of antiplatelet therapy. A literature search of MEDLINE, EMBASE, Scopus and Cochrane databases was conducted from each database's inception to July 16, 2020. Meta-analyses were conducted when possible. Results: In patients receiving long-term antiplatelet therapy and undergoing elective noncardiac surgery, the available evidence did not show a significant difference in major bleeding between a shorter vs longer antiplatelet interruption, with low certainty of evidence (COE). Compared with patients who received placebo perioperatively, aspirin continuation was associated with increased risk of major bleeding (relative risk [RR], 1.31; 95% CI, 1.15-1.50; high COE) and lower risk of major thromboembolism (RR, 0.74; 95% CI, 0.58-0.94; moderate COE). During antiplatelet interruption, bridging with low-molecular-weight heparin was associated with increased risk of major bleeding compared with no bridging (RR, 1.86; 95% CI, 1.24-2.79; very low COE). Continuation of antiplatelets during minor dental and ophthalmologic procedures was not associated with a statistically significant difference in the risk of major bleeding (very low COE). Conclusion: This systematic review summarizes the current evidence about the perioperative management of antiplatelet therapy and highlights the urgent need for further research, particularly with the increasing prevalence of patients taking 1 or more antiplatelet agents.

Electrocardiographic Interference on Bispectral Index Monitor: A Case of Crossed Wires.

The Bispectral Index (BIS) has been widely utilized to monitor patients' levels of consciousness during anesthesia. Despite its practicality and prevalence, BIS monitors have been reported to show erroneous readings due to various factors that interfere with the proper reading of the brain's electrical activity. We present a case where the BIS monitor misinterpreted the patient's cardiac activity as her neural activity and resulted in a falsely elevated BIS number despite proper placement and lack of underlying patient medical condition, including neurological injury. It is crucial to remain vigilant about monitoring and understanding BIS readings to assess patients' awareness and effectiveness of anesthesia properly.

Pneumothorax Following Breast Surgery at an Ambulatory Surgery Center.

Pneumothorax is a known complication following breast surgery but is likely underappreciated by anesthesiologists. Iatrogenic pneumothorax can be caused by needle injury during local anesthetic injection, surgical damage to the intercostal fascia or pleura, or pulmonary injury from mechanical ventilation. We present two cases of pneumothorax following bilateral mastectomy with bilateral pectoral blocks and immediate breast reconstruction. Both cases occurred at a freestanding ambulatory surgery center in patients with no history of lung disease. One patient was found to have bilateral pneumothoraxes after complaining of shortness of breath and chest pain in the post-operative care unit. The second patient was asymptomatic but found to have a right-sided pneumothorax on a chest X-ray (CXR) that was ordered to rule-out left-sided pneumothorax due to concern of intraoperative breach of the left chest wall. Both patients were treated with chest tubes, transferred to a nearby hospital, and discharged several days later. Anesthesiologists must be aware of this potentially life-threatening complication and consider pneumothorax in the differential diagnosis of perioperative hypoxemia, shortness of breath, chest pain, and hemodynamic collapse in patients undergoing breast surgery. Though traditionally diagnosed via radiograph, pneumothorax can be rapidly diagnosed with ultrasound. Tension pneumothorax should be decompressed immediately with a needle. A clinically significant, non-tension pneumothorax is treated with chest tube placement. Equipment necessary to treat pneumothorax should be available for emergency treatment in facilities wherever breast surgery is performed.

Anesthetic Challenges Posed by Heavy Kratom Users.

Kratom is a herbal and natural dietary supplement from Southeast Asia that is gaining popularity in the United States. Its leaves contain multiple psychoactive chemicals that stimulate opioid, alpha-2, and serotonergic receptors. Kratom is used as a stimulant and in the treatment of anxiety, pain, and opioid withdrawal. In most states, kratom can be purchased legally and is sold at smoke shops, gas stations, and online. To date, only limited data is available on the impact of habitual kratom use on patients undergoing anesthesia. The following case report highlights multiple anesthetic challenges posed by a heavy kratom user.

Acceptance of Dental Office Obstructive Sleep Apnea Screening among Minnesota State Fair Attendees.

Purpose: Obstructive sleep apnea (OSA) is a common breathing disorder; however, many individuals remain undiagnosed. The purpose of this study was to assess the comfort level of community-dwelling adults to participate in OSA screening in a dental office setting and survey the OSA risk levels of an adult population.Methods: This cross-sectional study was conducted among adults presenting at the University of Minnesota Driven to Discover Research Facility during the 2018 Minnesota State Fair. Participants completed a brief survey including the eight-item STOP-Bang questionnaire for OSA screening. Electronic tablets were used for data capture. Data analyses included descriptive statistics, t-tests, and Chi-square tests.Results: A total of 639 adults met the survey inclusion criteria (n=639). The majority of participants (88%) reported no prior OSA diagnosis. Based on STOP-Bang criteria, 61% (n=344) of the participants were at low, 29% (n=161) intermediate, and 10% (n= 56) high risk of OSA. A majority (64%) of participants reported being either "comfortable" or "very comfortable'"with OSA screening performed in a dental office setting.Conclusion: Over one third of participants with no prior OSA diagnosis were at moderate to high risk for OSA, and the majority stated that they would be comfortable undergoing OSA screening in a dental office setting. Dental hygienists screening patients for OSA with the STOP-BANG questionnaire are likely to have a high level of patient acceptance. Referring patients to the appropriate health care provider for further testing may increase timely diagnoses and treatment of OSA.

Hospital-Based Acute Care Within 7 Days of Discharge After Outpatient Arthroscopic Shoulder Surgery.

BACKGROUND: The rate of hospital-based acute care (defined as hospital transfer at discharge, emergency department [ED] visit, or subsequent inpatient hospital [IP] admission) after outpatient procedure is gaining momentum as a quality metric for ambulatory surgery. However, the incidence and reasons for hospital-based acute care after arthroscopic shoulder surgery are poorly understood. METHODS: We studied adult patients who underwent outpatient arthroscopic shoulder procedures in New York State between 2011 and 2013 using the Healthcare Cost and Utilization Project database. ER visits and IP admissions within 7 days of surgery were identified by cross-matching 2 independent Healthcare Cost and Utilization Project databases. RESULTS: The final cohort included 103,476 subjects. We identified 1867 (1.80%, 95% confidence interval [CI], 1.72%-1.89%) events, and the majority of these encounters were ER visits (1643, or 1.59%, 95% CI, 1.51%-1.66%). Direct IP admission after discharged was uncommon (224, or 0.22%, 95% CI, 0.19%-0.24%). The most common reasons for seeking acute care were musculoskeletal pain (23.78% of all events). Nearly half of all events (43.49%) occurred on the day of surgery or on postoperative day 1. Operative time exceeding 2 hours was associated with higher odds of requiring acute care (odds ratio [OR], 1.28; 99% CI, 1.08-1.51). High-volume surgical centers (OR, 0.67; 99% CI, 0.58-0.78) and regional anesthesia (OR, 0.72; 99% CI, 0.56-0.92) were associated with lower odds of requiring acute care. CONCLUSIONS: The rate of hospital-based acute care after outpatient shoulder arthroscopy was low (1.80%). Complications driving acute care visits often occurred within 1 day of surgery. Many of the events were likely related to surgery and anesthesia (eg, inadequate analgesia), suggesting that anesthesiologists may play a central role in preventing acute care visits after surgery.

Risk Adjustment for Medicare Total Knee Arthroplasty Bundled Payments.

The use of bundled payments is growing because of their potential to align providers and hospitals on the goal of cost reduction. However, such gain sharing could incentivize providers to "cherry-pick" more profitable patients. Risk adjustment can prevent this unintended consequence, yet most bundling programs include minimal adjustment techniques. This study was conducted to determine how bundled payments for total knee arthroplasty (TKA) should be adjusted for risk. The authors collected financial data for all Medicare patients (age≥65 years) undergoing primary unilateral TKA at an academic center over a period of 2 years (n=941). Multivariate regression was performed to assess the effect of patient factors on the costs of acute inpatient care, including unplanned 30-day readmissions. This analysis mirrors a bundling model used in the Medicare Bundled Payments for Care Improvement initiative. Increased age, American Society of Anesthesiologists (ASA) class, and the presence of a Medicare Major Complications/Comorbid Conditions (MCC) modifier (typically representing major complications) were associated with increased costs (regression coefficients, $57 per year; $729 per ASA class beyond I; and $3122 for patients meeting MCC criteria; P=.003, P=.001, and P<.001, respectively). Differences in costs were not associated with body mass index, sex, or race. If the results are generalizable, Medicare bundled payments for TKA encompassing acute inpatient care should be adjusted upward by the stated amounts for older patients, those with elevated ASA class, and patients meeting MCC criteria. This is likely an underestimate for many bundling models, including the Comprehensive Care for Joint Replacement program, incorporating varying degrees of postacute care. Failure to adjust for factors that affect costs may create adverse incentives, creating barriers to care for certain patient populations. [Orthopedics. 2016; 39(5):e911-e916.].

What Incentives Are Created by Medicare Payments for Total Hip Arthroplasty?

BACKGROUND: Differences in profitability and contribution margin (CM) between various patient populations may make certain patients particularly attractive (or unattractive) to providers. This study seeks to identify patient characteristics associated with increased profit and CM among Medicare patients undergoing total hip arthroplasty (THA). METHODS: The expected Medicare reimbursement for consecutive patients of Medicare-eligible age (65+ years) undergoing primary unilateral elective THA (n = 498) was calculated in accordance with Center for Medicare and Medicaid Services policy. Costs were derived from the hospital's cost accounting system. Profit and CM were calculated for each patient as reimbursement less total and variable costs, respectively. Patients were compared based on clinical and demographic factors by univariate and multivariate analyses. RESULTS: Medicare patients undergoing THA generated negative average profits but substantial positive CMs. Lower profit and CM were associated with higher American Society of Anesthesiologists Physical Status Classification (P < .01, P = .03), older age (P < .01), and longer length of stay (P < .01, P = .03). No association was found with gender, body mass index, or race. CONCLUSION: If our results are generalizable, Medicare patients requiring THA are currently financially attractive, but institutions have a long-term incentive to shift resources to more profitable patients and service lines, which may eventually restrict access to care for this population. THA providers have a financial incentive to favor Medicare patients with younger age, lower American Society of Anesthesiologists Physical Status Classification, and those who can be expected to require relatively short admissions. The Center for Medicare and Medicaid Services must strive to accurately match reimbursement rates to provider costs to avoid inequitable payments to providers and financial incentives discouraging treatment of high-risk patients or other patient subpopulations.

Are there identifiable risk factors and causes associated with unplanned readmissions following total knee arthroplasty?

We conducted a retrospective review of 3218 primary total knee arthroplasties (TKA) performed over two years at an urban academic hospital network using clinical and administrative data. Increased length of stay (LOS) was associated with readmission (P < 0.001). Readmission was not associated with age (P = 0.100), gender (P = 0.608), body mass index (P = 0.329), or staged bilateral procedures (P = 0.420). The most common readmitting diagnoses were post-operative infection (22.5%), hematoma (10.1%), pulmonary embolus (7.9%) and deep vein thrombosis (5.6%). Of readmissions, 53.9% were for surgical reasons and 46.1% were for medical reasons. Certain interventions described in previous literature may be more successful in minimizing unplanned readmissions by focusing on patients with extended LOS, elevated infection risk and low socioeconomic status.

What are the economic consequences of unplanned readmissions after TKA?

BACKGROUND: In 2009, the Center for Medicare & Medicaid Services (CMS) began penalizing hospitals with high rates of 30-day readmissions after hospitalizations for certain conditions. This policy will expand to include TKA in 2015. QUESTIONS/PURPOSES: What are the median profits and contribution margins of: (1) Medicare-reimbursed TKA, (2) 30-day TKA readmission, and (3) entire episode of care for readmitted TKA patients within 30 days compared to nonreadmitted patients? (4) Under new CMS guidelines, what financial penalty will the authors' institution face if its arthroplasty readmission rate exceeds the national average? METHODS: A retrospective review of 3218 primary TKAs performed during 2 years at a large urban academic hospital network was conducted using administrative and financial data. RESULTS: The median profit and contribution margins, respectively, were as follows: TKA episode, USD 5209 and USD 11,726; 30-day readmission, USD 608 and USD 3814; TKA visit with readmission, USD 2855 and USD 13,901; TKA visit without readmission, USD 5300 and USD 11,652. Readmission penalties could reach USD 6.21 million per year for the authors' institution. DISCUSSION: If our results are generalizable, unplanned TKA readmissions lead to diminished total profit. Although associated with a positive contribution margin, this is likely to be a short-term phenomenon as the new CMS policy will result in readmissions coming at a steep cost to referral centers.

The impact of complications following open colectomy on hospital finances: a retrospective cohort study.

BACKGROUND: When hospitals suffer financial losses when postoperative complications occur, they may have a direct financial incentive to initiate quality improvement programs. The purpose of this research was to determine the relationship between complications following open colectomy and hospital finances. METHODS: After obtaining Institutional Review Board approval, we conducted a retrospective chart review of 276 open colectomies performed at the Hospital of the University of Pennsylvania. The medical records were manually reviewed for complications that occurred within 30 days after surgery. Financial information, including total, fixed and variable costs, was obtained from the hospital's cost accounting database. Reimbursement assuming payment by Medicare was calculated. Differences in costs, reimbursements and total margins were analyzed. RESULTS: Of 276 patient records reviewed, 61 (22%) of the patients experienced postoperative complications. When complications occurred, mean total costs increased from $23,101 to $48,180, fixed costs increased from $14,516 to $30,339 and variable costs increased from $8,535 to $17,848 (P < 0.001 for each comparison); the mean reimbursement increased from $23,231 to $35,651 (P < 0.001); and the total margin decreased from $131 to - $12,528 (P < 0.001). Complications were associated with a more than twofold increase in length of stay in the hospital. Multiple regression modeling indicated similar increases in each of the financial variables and length of stay as a result of postoperative complications. The impact of these complications on each outcome measure was similar in effect for patients in the matched subset of 100 patients. CONCLUSION: Our results demonstrate a financial incentive for hospitals to investigate quality improvement measures to prevent postoperative complications and avoid the associated financial losses.

Risk factors, causes, and the economic implications of unplanned readmissions following total hip arthroplasty.

In order to identify risk factors for readmissions following total hip arthroplasty (THA) and the causes and financial implications of such readmissions, we analyzed clinical and administrative data on 1583 consecutive primary THAs performed at a single institution. The 30-day readmission rate was 6.51%. Increased age, length of stay, and body mass index were associated with significantly higher readmission rates. The most common re-admitting diagnoses were deep infection, pain, and hematoma. Average profit was lower for episodes of care with readmissions ($1548 vs. $2872, P=0.028). If Medicare stops reimbursing for THA readmissions, the institution under review would sustain an average net loss of $11,494 for episodes of care with readmissions and would need to maintain readmission rates below 23.6% in order to remain profitable.

Stopping randomized trials early for benefit and estimation of treatment effects: systematic review and meta-regression analysis.

CONTEXT: Theory and simulation suggest that randomized controlled trials (RCTs) stopped early for benefit (truncated RCTs) systematically overestimate treatment effects for the outcome that precipitated early stopping. OBJECTIVE: To compare the treatment effect from truncated RCTs with that from meta-analyses of RCTs addressing the same question but not stopped early (nontruncated RCTs) and to explore factors associated with overestimates of effect. DATA SOURCES: Search of MEDLINE, EMBASE, Current Contents, and full-text journal content databases to identify truncated RCTs up to January 2007; search of MEDLINE, Cochrane Database of Systematic Reviews, and Database of Abstracts of Reviews of Effects to identify systematic reviews from which individual RCTs were extracted up to January 2008. STUDY SELECTION: Selected studies were RCTs reported as having stopped early for benefit and matching nontruncated RCTs from systematic reviews. Independent reviewers with medical content expertise, working blinded to trial results, judged the eligibility of the nontruncated RCTs based on their similarity to the truncated RCTs. DATA EXTRACTION: Reviewers with methodological expertise conducted data extraction independently. RESULTS: The analysis included 91 truncated RCTs asking 63 different questions and 424 matching nontruncated RCTs. The pooled ratio of relative risks in truncated RCTs vs matching nontruncated RCTs was 0.71 (95% confidence interval, 0.65-0.77). This difference was independent of the presence of a statistical stopping rule and the methodological quality of the studies as assessed by allocation concealment and blinding. Large differences in treatment effect size between truncated and nontruncated RCTs (ratio of relative risks <0.75) occurred with truncated RCTs having fewer than 500 events. In 39 of the 63 questions (62%), the pooled effects of the nontruncated RCTs failed to demonstrate significant benefit. CONCLUSIONS: Truncated RCTs were associated with greater effect sizes than RCTs not stopped early. This difference was independent of the presence of statistical stopping rules and was greatest in smaller studies.

Messages about black-box warnings: a comparative analysis of reports from the FDA and lay media in the US.

BACKGROUND: The US FDA and lay media are important sources of information for the public about the risks of adverse events associated with drugs, yet the quality of FDA and US lay media reports about medication 'black-box' warnings, which highlight potentially severe adverse events from medications, is unknown. OBJECTIVE: To determine and compare the content of FDA and US lay media reports about medication black-box warnings. METHODS: We assessed FDA and US lay media reports about medication black-box warnings published or aired between 1 January 2003 and 31 December 2007 for the presence of six core message components, including (i) the affected drug's brand name; (ii) generic name; (iii) treatment indication; (iv) reason for the black-box warning; (v) clinical recommendations for patients, such as warning signs and symptoms of the adverse effect addressed by the black-box warning; and (vi) encouragement to discuss the issue with a healthcare provider, and additional characteristics. RESULTS: FDA reports presented more core information than lay media reports (median 5 vs 3 message components; p < 0.001). FDA reports were more likely to mention generic names (84.6% vs 18.1%; p < 0.001) of affected drugs, while lay media reports less frequently detailed clinical recommendations for patients (43.9% vs 96.2%; p < 0.001). Only 10.6% of lay media reports encouraged patients to seek additional information from their healthcare provider, compared with 48.1% of FDA reports (p < 0.001). CONCLUSIONS: FDA and US lay media reports about medication black-box warnings presented different information. This may reflect a difference in underlying motivation for reporting of news about risks of adverse drug events. It may also indicate a lack of agreement and understanding about the best methods to communicate risk information to the public, thus indicating areas for future research.