Slide set (PDF) at http://dcme.co/2015_ASA_Wellness_Ellis
The literature has numerous studies examining the effect of timing of surgery after MI and coronary stenting and MACE (major adverse cardiovascular events). However, for stroke, data is sparse.
Now comes a study from Denmark, published in JAMA. In Denmark, all medical data is collected (single payer), allowing retrospective databases studies to be done on complete, reliable datasets. The disadvantage is that it is an ethnically uniform database, which the authors correctly say potentially limits the generalizability of the results. They looked at “Danish nationwide cohort study (2005-2011) including all patients aged 20 years or older undergoing elective noncardiac surgeries (n=481 183 surgeries)”; 7137 had had prior stroke.
What I found fascinating is that a key part of their data was a nationwide Anesthesia database:
Information on several surgery-related variables, including whether the surgery was acute or elective, was retrieved from the Danish Anesthesia Register, in which all surgeries requiring anesthesia have been registered since mid-2004.
So, what did they find?
In summary, we demonstrated that prior ischemic stroke, irrespective of time between ischemic stroke and surgery, was associated with an adjusted 1.8- and 4.8-fold increased relative risk of 30-day mortality and 30-day MACE, respectively, compared with patients without prior stroke. Second, we demonstrated a strong time-dependent relationship between prior stroke and adverse postoperative outcome, with patients experiencing a stroke less than 3 months prior to surgery at particularly high risk. The risk stabilized after approximately 9 months. Third, the increased relative risks associated with prior stroke were found to be of at least similar magnitudes in low- and intermediate-risk surgeries, as in high-risk surgeries.
Elective surgery in the first 3 months is associated with much higher MACE rates. These rates stabilize by 9 months s/p CVA.
The authors did multiple analyses to try to limit the confounding effect that early surgery after stroke might indicate a not-elective indication for surgery. For example, they looked at the association of time after stroke and total knee or hip replacement (without fracture – presumably elective), and found similar elevated rates of MACE in the first 3 months.
There is possible room for improvement, since only 52% of prior CVA patients were chronically on statins, and only 65% on antiplatelet meds (such as aspirin and/or plavix) before surgery. Indeed, when adjusted for comorbidities, they found that in patients with prior CVA, chronic statins and antiplatelets meds were associated with reductions in postop MACE, including death from any cause.
What are some take away points?
Saturday at NY State Society of Anesthesiologists PGA meeting, Dr. Ellis, Anesthesia Camp Course Director, moderated a panel and lectured on Perioperative Beta Blockade. Here are his Power Point slides: http://goo.gl/LnGWF8.
On Friday, Dr. Ellis also lectured at the PGA on Preoperative Cardiac Evaluation. Power Point slides: http://goo.gl/lM0Kqa.
Less emphasis on traditional CAD risk factors; more emphasis on CHR, arrhythmias, and frailty.
I talked about Perioperative Beta Blockade; click here for a PDF of the slides shown.
Your feedback, of course is appreciated.
Does your institution have automated reminders to continue perioperative beta blockade in paients taking them chronically?
1. Chest. 2013 May;143(5):1284-93. doi: 10.1378/chest.12-1132. Serum bicarbonate level improves specificity of STOP-bang screening for obstructive sleep apnea. Chung F, Chau E, Yang Y, Liao P, Hall R, Mokhlesi B. Department of Anesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada. firstname.lastname@example.org BACKGROUND: The STOP-Bang questionnaire is a validated screening tool for the identification of surgical patients with obstructive sleep apnea (OSA). A STOP-Bang score ≥ 3 is highly sensitive but only moderately specific. Apnea/hypopnea during sleep can lead to intermittent hypercapnia and may result in serum bicarbonate (HCO₃⁻) retention. The addition of serum HCO₃⁻ level to the STOP-Bang questionnaire may improve its specificity. METHODS: Four thousand seventy-seven preoperative patients were approached for consent and screened by the STOP-Bang questionnaire. Polysomnography was performed and preoperative HCO₃⁻ level was collected in 384 patients. Study participants were randomly assigned to a derivation or validation cohort. Predictive parameters (sensitivity, specificity, positive and negative predictive values) for STOP-Bang score and serum HCO₃⁻ level were calculated. RESULTS: In the derivation cohort, with a STOP-Bang score ≥ 3, the specificity for all OSA, moderate/severe OSA, and severe OSA was 37.0%, 30.4%, and 27.7%, respectively. HCO₃⁻ level of 28 mmol/L was selected as a cutoff for analysis. With the addition of HCO₃⁻ level ≥ 28 mmol/L to the STOP-Bang score ≥ 3, the specificity for all OSA, moderate/severe OSA, and severe OSA improved to 85.2%, 81.7%, and 79.7%, respectively. Similar improvement was observed in the validation cohort. CONCLUSION: Serum HCO₃⁻ level increases the specificity of STOP-Bang screening in predicting moderate/severe OSA. We propose a two-step screening process. The first step uses a STOP-Bang score to screen patients, and the second step uses serum HCO₃⁻ level in those with a STOP-Bang score ≥ 3 for increased specificity. PMID: 23238577 [PubMed - in process] 2. Anesth Analg. 2012 Nov;115(5):1060-8. doi: 10.1213/ANE.0b013e318269cfd7. Epub 2012 Aug 10. Society for Ambulatory Anesthesia consensus statement on preoperative selection of adult patients with obstructive sleep apnea scheduled for ambulatory surgery. Joshi GP, Ankichetty SP, Gan TJ, Chung F. Department of Anesthesiology and Pain Management, University of Texas Southwestern Medical Center, Dallas, TX 75390-9068, USA. email@example.com The suitability of ambulatory surgery for a patient with obstructive sleep apnea (OSA) remains controversial because of concerns of increased perioperative complications including postdischarge death. Therefore, a Society for Ambulatory Anesthesia task force on practice guidelines developed a consensus statement for the selection of patients with OSA scheduled for ambulatory surgery. A systematic review of the literature was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Although the studies evaluating perioperative outcome in OSA patients undergoing ambulatory surgery are sparse and of limited quality, they do provide useful information that can guide clinical practice. Patients with a known diagnosis of OSA and optimized comorbid medical conditions can be considered for ambulatory surgery, if they are able to use a continuous positive airway pressure device in the postoperative period. Patients with a presumed diagnosis of OSA, based on screening tools such as the STOP-Bang questionnaire, and with optimized comorbid conditions, can be considered for ambulatory surgery, if postoperative pain can be managed predominantly with nonopioid analgesic techniques. On the other hand, OSA patients with nonoptimized comorbid medical conditions may not be good candidates for ambulatory surgery. What other guidelines are available on this topic? The American Society of Anesthesiologists (ASA) practice guidelines for management of surgical patients with OSA published in 2006. Why was this guideline developed? The ASA guidelines are outdated because several recent studies provide new information such as validated screening tools for clinical diagnosis of OSA and safety of ambulatory laparoscopic bariatric surgery in OSA patients. Therefore, an update on the selection of patients with OSA undergoing ambulatory surgery is warranted. How does this guideline differ from existing guidelines? Unlike the ASA guidelines, this consensus statement recommends the use of the STOP-Bang criteria for preoperative OSA screening and considers patients' comorbid conditions in the patient selection process. Also, current literature does not support the ASA recommendations that upper abdominal procedures are not appropriate for ambulatory surgery. Why does this guideline differ from existing guidelines? This consensus statement differs from existing ASA guidelines because of the availability of new evidence. PMID: 22886843 [PubMed - indexed for MEDLINE] 3. N Engl J Med. 2013 Jun 20;368(25):2352-3. doi: 10.1056/NEJMp1302941. A rude awakening--the perioperative sleep apnea epidemic. Memtsoudis SG, Besculides MC, Mazumdar M. Department of Anesthesiology, Hospital for Special Surgery, Weill Medical College of Cornell University, New York, USA. PMID: 23782177 [PubMed - in process] 4. Reg Anesth Pain Med. 2013 Jul-Aug;38(4):274-81. doi: 10.1097/AAP.0b013e31828d0173. Sleep Apnea and Total Joint Arthroplasty under Various Types of Anesthesia: A Population-Based Study of Perioperative Outcomes. Memtsoudis SG, Stundner O, Rasul R, Sun X, Chiu YL, Fleischut P, Danninger T, Mazumdar M. From the *Department of Anesthesiology, Hospital for Special Surgery, †Division of Biostatistics and Epidemiology, Department of Public Health; and ‡Department of Anesthesiology, New York-Presbyterian Hospital, Weill Medical College of Cornell University, New York, NY. BACKGROUND AND OBJECTIVES: The presence of sleep apnea (SA) among surgical patients has been associated with significantly increased risk of perioperative complications. Although regional anesthesia has been suggested as a means to reduce complication rates among SA patients undergoing surgery, no data are available to support this association. We studied the association of the type of anesthesia and perioperative outcomes in patients with SA undergoing joint arthroplasty. METHODS: Drawing on a large administrative database (Premier Inc), we analyzed data from approximately 400 hospitals in the United States. Patients with a diagnosis of SA who underwent primary hip or knee arthroplasty between 2006 and 2010 were identified. Perioperative outcomes were compared between patients receiving general, neuraxial, or combined neuraxial-general anesthesia. RESULTS: We identified 40,316 entries for unique patients with a diagnosis for SA undergoing primary hip or knee arthroplasty. Of those, 30,024 (74%) had anesthesia-type information available. Approximately 11% of cases were performed under neuraxial, 15% under combined neuraxial and general, and 74% under general anesthesia. Patients undergoing their procedure under neuraxial anesthesia had significantly lower rates of major complications than did patients who received combined neuraxial and general or general anesthesia (16.0%, 17.2%, and 18.1%, respectively; P = 0.0177). Adjusted risk of major complications for those undergoing surgery under neuraxial or combined neuraxial-general anesthesia compared with general anesthesia was also lower (odds ratio, 0.83 [95% confidence interval, 0.74-0.93; P = 0.001] vs odds ratio, 0.90 [95% confidence interval, 0.82-0.99; P = 0.03]). CONCLUSIONS: Barring contraindications, neuraxial anesthesia may convey benefits in the perioperative outcome of SA patients undergoing joint arthroplasty. Further research is needed to enhance an understanding of the mechanisms by which neuraxial anesthesia may exert comparatively beneficial effects. PMID: 23558371 [PubMed - in process] 5. Anesthesiology. 2012 Jul;117(1):188-205. doi: 10.1097/ALN.0b013e31825add60. Obesity hypoventilation syndrome: a review of epidemiology, pathophysiology, and perioperative considerations. Chau EH, Lam D, Wong J, Mokhlesi B, Chung F. Department of Anesthesiology, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada. Obesity hypoventilation syndrome (OHS) is defined by the triad of obesity, daytime hypoventilation, and sleep-disordered breathing without an alternative neuromuscular, mechanical, or metabolic cause of hypoventilation. It is a disease entity distinct from simple obesity and obstructive sleep apnea. OHS is often undiagnosed but its prevalence is estimated to be 10-20% in obese patients with obstructive sleep apnea and 0.15-0.3% in the general adult population. Compared with eucapnic obese patients, those with OHS present with severe upper airway obstruction, restrictive chest physiology, blunted central respiratory drive, pulmonary hypertension, and increased mortality. The mainstay of therapy is noninvasive positive airway pressure. Currently, information regarding OHS is extremely limited in the anesthesiology literature. This review will examine the epidemiology, pathophysiology, clinical characteristics, screening, and treatment of OHS. Perioperative management of OHS will be discussed last. PMID: 22614131 [PubMed - in process]
Dr London and colleagues from San Francisco VA have just published a study in JAMA (retrospective; propensity analysis) showing that beta blockers are NOT protective in vascular surgery. However, they are in non-vascular noncardiac surgery. The protection increases as the RCRI increases.
Hypotheses as to why no protection in vascular surgery patients:
I asked Dr. London if they had analysed bleeding and transfusion in this cohort. They’d like to do so, but await funding to be able to examine.
By Joe Elia
Patients with heart failure and atrial fibrillation do not benefit as much from beta-blocker therapy as those with sinus rhythm, according to a meta-analysis in the Journal of the American College of Cardiology: Heart Failure.
Researchers analyzed mortality outcomes from four studies including over 8500 patients with heart failure and reduced left-ventricular ejection fraction (<40%). Roughly 20% also had atrial fibrillation. Although those with atrial fibrillation who received beta-blockers had lower mortality risks than those receiving placebo (odds ratio, 0.86), patients with sinus rhythm fared much better (OR, 0.63). In addition, beta-blockers did not reduce hospitalizations for heart failure among patients with atrial fibrillation, whereas they did among those with sinus rhythm.
Editorialists call the study, “hypothesis-generating,” and conclude that the results “at a minimum” suggest that treatment for those with heart failure and atrial fibrillation “should be approached differently” from those with sinus rhythm.
JACC: Heart Failure article (Free)
Meta analysis has its limitations. This one in today’s JAMA seems to condemn transfusion in acute MI. Interesting, that in the perioperative arena, blood loss is associated with increased CV complications.