Frequency and Outcomes of Preoperative Stress Testing in Total Hip and Knee Arthroplasty from 2004 to 2017.

Importance: Cardiac stress testing is often performed prior to noncardiac surgery, although trends in use of preoperative stress testing and the effect of testing on cardiovascular outcomes are currently unknown. Objective: To describe temporal trends and outcomes of preoperative cardiac stress testing from 2004 to 2017. Design, Setting, and Participants: Cross-sectional study of patients undergoing elective total hip or total knee arthroplasty from 2004 to 2017. Trend analysis was conducted using Joinpoint and generalized estimating equation regression. The study searched IBM MarketScan Research Databases inpatient and outpatient health care claims for private insurers including supplemental Medicare coverage and included patients with a claim indicating an elective total hip or total knee arthroplasty from January 1, 2004, to December 31, 2017. Exposures: Elective total hip or knee arthroplasty. Main Outcomes and Measures: Trend in yearly frequency of preoperative cardiac stress testing. Results: The study cohort consisted of 801 396 elective total hip (27.9%; n = 246 168 of 801 396) and total knee (72.1%; 555 228 of 801 396) arthroplasty procedures, with a median age of 62 years (interquartile range, 57-70 years) and 58.1% women (n = 465 545 of 801 396). The overall rate of stress testing during the study period was 10.4% (n = 83 307 of 801 396). The rate of stress tests increased 0.65% (95% CI, 0.09-1.21; P = .03) annually from quarter (Q) 1 of 2004 until Q2 of 2006. A joinpoint was identified at Q3 of 2006 (95% CI, 2005 Q4 to 2007 Q4) when preoperative stress test use decreased by -0.71% (95% CI, -0.79% to 0.63%; P < .001) annually. A second joinpoint was identified at the Q4 of 2013 (95% CI, 2011 Q3 to 2015 Q3), when the decline in stress testing rates slowed to -0.40% (95% CI, -0.57% to -0.24%; P < .001) annually. The overall rate of myocardial infarction and cardiac arrest was 0.24% (n = 1677 of 686 067). Rates of myocardial infraction and cardiac arrest were not different in patients with at least 1 Revised Cardiac Risk Index condition who received a preoperative stress test and those who did not (0.60%; n = 221 of 36 554 vs 0.57%; n = 694 of 122 466; P = .51). Conclusions and Relevance: The frequency of preoperative stress testing declined annually from 2006 through 2017. Among patients with at least 1 Revised Cardiac Risk Index condition, no difference was observed in cardiovascular outcomes between patients who did and did not undergo preoperative testing.

Development and Pilot Study of an iOS Smartphone Application for Perioperative Functional Capacity Assessment.

BACKGROUND: Functional capacity assessment plays a core role in the preoperative evaluation. The Duke Activity Status Index (DASI) and the 6-minute walk test (6MWT) are 2 methods that have demonstrated the ability to evaluate functional capacity and predict perioperative outcomes. Smartphones offer a novel method to facilitate functional capacity assessment as they can easily administer a survey and accelerometers can track patient activity during a 6MWT. We developed a smartphone application to administer a 6MWT and DASI survey and performed a pilot study to evaluate the accuracy of a smartphone-based functional capacity tool in our Anesthesia and Perioperative Medicine Clinic. METHODS: Using the Apple ResearchKit software platform, we developed an application that administers a DASI survey and 6MWT on an iOS smartphone. The DASI was presented to the patient 1 question on the screen at a time and the application calculated the DASI score and estimated peak oxygen uptake (VO2). The 6MWT used the CMPedometer class from Apple's core motion facility to retrieve accelerometer data collected from the device's motion coprocessor to estimate steps walked. Smartphone estimated steps were compared to a research-grade pedometer using the intraclass correlation coefficient (ICC). Distance walked was directly measured during the 6MWT and we performed a multivariable linear regression with biometric variables to create a distance estimation algorithm to estimate distance walked from the number of steps recorded by the application. RESULTS: Seventy-eight patients were enrolled in the study and completed the protocol. Steps measured by the smartphone application as compared to the pedometer demonstrated moderate agreement with an ICC (95% CI) of 0.87 (0.79-0.92; P = .0001). The variables in the distance estimation algorithm included (ß coefficient [slope], 95% CI) steps walked (0.43, 0.29-0.57; P < .001), stride length (0.38, 0.22-0.53; P < .001), age in years (-1.90, -3.06 to -0.75; P = .002), and body mass index (-2.59, -5.13 to -0.06; P = .045). The overall model fit was R = 0.72, which indicates a moderate level of goodness of fit and explains 72% of the variation of distance walked during a 6MWT. CONCLUSIONS: Our pilot study demonstrated that a smartphone-based functional capacity assessment is feasible using the DASI and 6MWT. The DASI was easily completed by patients and the application clearly presented the results of the DASI to providers. Our application measured steps walked during a 6MWT moderately well in a preoperative patient population; however, future studies are needed to improve the smartphone application's step-counting accuracy and distance estimation algorithm.

Preoperative Evaluation for Ambulatory Anesthesia: What, When, and How?

Most surgery in the United States occurs in offices, free-standing surgicenters, and hospital-based outpatient facilities. Patients are frequently elderly with comorbidities, and procedures are increasingly complex. Traditionally, patients have been evaluated on the day of surgery by anesthesia providers. Obtaining information on patients' health histories, establishing criteria for appropriateness, and communicating medication instructions streamline throughput, lower cancellations and delays, and improve provider and patient satisfaction. Routine testing does not lower risk or improve outcomes. Evaluating and optimizing patients with significant diseases, especially those with suboptimal management, has positive impact on ambulatory surgery and anesthesia.

Intraoperative Use of Nondepolarizing Neuromuscular Blocking Agents During Cardiac Surgery and Postoperative Pulmonary Complications: A Prospective Randomized Trial.

OBJECTIVE: Nondepolarizing neuromuscular blocking agents (NMBAs) are associated with perioperative complications in noncardiac surgery; however, little is known about their effect on cardiac surgery. This study assessed the effect of neuromuscular blockade (NMB) on the incidence of postoperative pulmonary complications (PPCs) after cardiac surgery and operating conditions. DESIGN: Prospective, randomized clinical trial with blinded outcomes assessment. SETTING: University hospital, single institution. PARTICIPANTS: Adult patients having cardiac surgery requiring cardiopulmonary bypass. INTERVENTIONS: One hundred patients were randomized to receive succinylcholine (group SUX) for intubation with no further NMB administered or cisatracurium (group CIS) for intubation and maintenance NMB. The primary outcome was a composite incidence of PPCs in the 72 hours after elective cardiac surgery. PPCs included failure to extubate within 24 hours, need for reintubation, pneumonia, aspiration, unanticipated need for noninvasive respiratory support, acute respiratory distress, and mortality from respiratory arrest. The secondary outcome was the adequacy of operating conditions as assessed by blinded surgeon survey (including a rating of surgical conditions on a Likert scale from 1 = poor to 5 = excellent), anesthesiologist report, and patient questionnaire. MEASUREMENTS AND MAIN RESULTS: The composite incidence of PPCs did not differ between groups (8 of 50 patients in both groups; 16%). Mean surgeon rating of surgical conditions was lower in the SUX group (4.65 ± 0.85 v 4.96 ± 0.20, p = 0.02). CONCLUSION: Although avoiding nondepolarizing NMBA is feasible, doing so worsened operating conditions and did not reduce the incidence of postoperative pulmonary complications.

Unrecognized tamponade diagnosed pre-induction by focused echocardiography.

PURPOSE: We report a case of unrecognized cardiac tamponade diagnosed pre-induction by focused transthoracic echocardiography (TTE). The value of focused perioperative TTE, the anesthetic implications of Churg-Strauss syndrome, and the diagnosis of cardiac tamponade are discussed. CLINICAL FEATURES: A 58-yr-old man with a history of severe asymptomatic aortic stenosis presented for elective endoscopic sinus surgery for intractable nasal polyps with recurrent sinusitis. His cardiologist and cardiac surgeon had recommended proceeding with surgery, as aortic valve replacement was not indicated because he was asymptomatic. Prior to induction, a focused TTE was performed by anesthesia in order to document the degree of aortic stenosis, baseline ventricular function, and baseline volume status. This provided a baseline for comparison in case the patient's hemodynamic status should deteriorate intraoperatively. Unexpectedly, the TTE examination revealed cardiac tamponade. After confirmation of the diagnosis by cardiology, urgent pericardiocentesis was performed. A diagnosis of Churg-Strauss syndrome was ultimately made, and the patient was treated with high-dose prednisone therapy. CONCLUSION: Focused TTE has significant clinical utility for the diagnosis and assessment of hemodynamically significant cardiac conditions, particularly in the complex patient where clinical examination is challenging and echocardiographic findings can have immediate management implications.