Preoperative levels of natriuretic peptides and the incidence of postoperative atrial fibrillation after noncardiac surgery: a prospective cohort study

BACKGROUND

Postoperative atrial fibrillation (POAF) is associated with clinically significant short- and long-term complications after noncardiac surgery. Our aim was to describe the incidence of clinically important POAF after noncardiac surgery and establish the prognostic value of N-terminal pro-brain-type natriuretic peptide (NT-proBNP) in this context.

METHODS

The Vascular events In noncardiac Surgery patIents cOhort evaluatioN (VISION) Study was a prospective cohort study involving patients aged 45 years and older who had inpatient noncardiac surgery that was performed between August 2007 and November 2013. We determined 30-day incidence of clinically important POAF (i.e., resulting in angina, congestive heart failure, symptomatic hypotension or requiring treatment) using logistic regression models to analyze the association between preoperative NT-proBNP and POAF.

RESULTS

In 37 664 patients with no history of atrial fibrillation, we found that the incidence of POAF was 1.0% (95% confidence interval [CI] 0.9%-1.1%; 369 events); 3.2% (95% CI 2.3%-4.4%) in patients undergoing major thoracic surgery, 1.3% (95% CI 1.2%-1.5%) in patients undergoing major nonthoracic surgery and 0.2% (95% CI 0.1%-0.3%) in patients undergoing low-risk surgery. In a subgroup of 9789 patients with preoperative NT-proBNP measurements, the biomarker improved the prediction of POAF risk over conventional prognostic factors (likelihood ratio test p < 0.001; fraction of new information from NT-proBNP was 16%). Compared with a reference NT-proBNP measurement set at 100 ng/L, adjusted odds ratios for the occurrence of POAF were 1.31 (95% CI 1.15-1.49) at 200 ng/L, 2.07 (95% CI 1.27-3.36) at 1500 ng/L and 2.39 (95% CI 1.26-4.51) at 3000 ng/L.

INTERPRETATION

We determined that the incidence of clinically important POAF after noncardiac surgery was 1.0%. We also found that preoperative NT-proBNP levels were associated with POAF independent of established prognostic factors. Trial registration: ClinicalTrials.gov, no. NCT00512109.

Association between complications and death within 30 days after noncardiac surgery

BACKGROUND

Among adults undergoing contemporary noncardiac surgery, little is known about the frequency and timing of death and the associations between perioperative complications and mortality. We aimed to establish the frequency and timing of death and its association with perioperative complications.

METHODS

We conducted a prospective cohort study of patients aged 45 years and older who underwent inpatient noncardiac surgery at 28 centres in 14 countries. We monitored patients for complications until 30 days after surgery and determined the relation between these complications and 30-day mortality using a Cox proportional hazards model.

RESULTS

We included 40 004 patients. Of those, 715 patients (1.8%) died within 30 days of surgery. Five deaths (0.7%) occurred in the operating room, 500 deaths (69.9%) occurred after surgery during the index admission to hospital and 210 deaths (29.4%) occurred after discharge from the hospital. Eight complications were independently associated with 30-day mortality. The 3 complications with the largest attributable fractions (AF; i.e., potential proportion of deaths attributable to these complications) were major bleeding (6238 patients, 15.6%; adjusted hazard ratio [HR] 2.6, 95% confidence interval [CI] 2.2-3.1; AF 17.0%); myocardial injury after noncardiac surgery [MINS] (5191 patients, 13.0%; adjusted HR 2.2, 95% CI 1.9-2.6; AF 15.9%); and sepsis (1783 patients, 4.5%; adjusted HR 5.6, 95% CI 4.6-6.8; AF 12.0%).

INTERPRETATION

Among adults undergoing noncardiac surgery, 99.3% of deaths occurred after the procedure and 44.9% of deaths were associated with 3 complications: major bleeding, MINS and sepsis. Given these findings, focusing on the prevention, early identification and management of these 3 complications holds promise for reducing perioperative mortality. Study registration: ClinicalTrials.gov, no. NCT00512109.

Patient coping and expectations about recovery predict the development of chronic post-surgical pain after traumatic tibial fracture repair

BACKGROUND

The association of patient expectations about recovery with the development of chronic post-surgical pain (CPSP) is uncertain.

METHODS

Three hundred and fifty-nine patients enrolled in the SPRINT trial completed the Somatic Preoccupation and Coping (SPOC) questionnaire six weeks after a traumatic tibial fracture repair. The SPOC questionnaire measures patients' somatic complaints, coping, and optimism for recovery. Using adjusted models, we explored the association of SPOC scores with ≥ mild CPSP and ≥ moderate pain interference with activity at one yr after surgery.

RESULTS

Of 267 tibial fracture patients with data available for analysis, 147 (55.1%) reported CPSP at one yr. The incidence of CPSP was 37.6% among those with low (≤40) SPOC scores, 54.1% among those with intermediate (41-80) scores, and 81.7% among those with high (>80) scores. Addition of SPOC scores to an adjusted regression model to predict CPSP improved the c-statistic from 0.61 (95% CI 0.55-0.68) to 0.70 (95% CI 0.64-0.76, P=0.005 for the difference) and found the greatest risk was associated with high SPOC scores (OR 6.56, 95% CI 2.90-14.81). Similarly, an adjusted regression model to predict pain interference with function at one yr (c-statistic 0.77, 95% CI 0.71-0.83) found the greatest risk for those with high SPOC scores (OR 10.10, 95% CI 4.26-23.96).

CONCLUSIONS

Patient's coping and expectations of recovery, as measured by the SPOC questionnaire, is an independent predictor of CPSP and pain interference one yr after traumatic tibial fracture. Future studies should explore whether these beliefs can be modified, and if doing so improves prognosis.

CLINICAL TRIAL REGISTRATION

NCT 00038129.

Correction to: Advances in anesthesia technology are improving patient care, but many challenges remain

Unfortunately, after publication of this article [1], it was noticed that the name of Ashraf A. Dahaba is incorrectly displayed as Ashraf Dahaba. The full, corrected author list can be seen here.

The role of randomized cluster crossover trials for comparative effectiveness testing in anesthesia: design of the Benzodiazepine-Free Cardiac Anesthesia for Reduction in Postoperative Delirium (B-Free) trial

Increasingly, clinicians and researchers recognize that studies of interventions need to evaluate not only their therapeutic efficacy (i.e., the effect on an outcome in ideal, controlled settings) but also their real-world effectiveness in broad, unselected patient groups. Effectiveness trials inform clinical practice by comparing variations in therapeutic approaches that fall within the standard of care. In this article, we discuss the need for studies of comparative effectiveness in anesthesia and the limitations of individual patient randomized-controlled trials in determining comparative effectiveness. We introduce the concept of randomized cluster crossover trials as a means of answering questions of comparative effectiveness in anesthesia, using the design of the Benzodiazepine-Free Cardiac Anesthesia for Reduction in Postoperative Delirium (B-Free) trial (Clinicaltrials.gov identifier NCT03053869).

Advances in anesthesia technology are improving patient care, but many challenges remain

Although significant advances in clinical monitoring technology and clinical practice development have taken place in the last several decades, in this editorial we argue that much more still needs to be done. We begin by identifying many of the improvements in perioperative technology that have become available in recent years; these include electroencephalographic depth of anesthesia monitoring, bedside ultrasonography, advanced neuromuscular transmission monitoring systems, and other developments. We then discuss some of the perioperative technical challenges that remain to be satisfactorily addressed, such as products that incorporate poor software design or offer a confusing user interface. Finally we suggest that the journal support initiatives to help remedy this problem by publishing reports on the evaluation of medical equipment as a means to restore the link between clinical research and clinical end-users.

Preoperative antihypertensive medication intake and acute kidney injury after major vascular surgery

OBJECTIVE

Postoperative acute kidney injury (AKI) is frequent after major vascular surgery and is associated with significant morbidity and mortality. It remains unclear whether the administration of combined oral antihypertensive medications on the day of surgery can increase the risk of postoperative AKI.

METHODS

We performed a retrospective cohort study of hypertensive patients undergoing elective major vascular surgery to determine the association between the number of antihypertensive medications continued on the morning of surgery and AKI at 48 hours postoperatively.

RESULTS

A total of 406 patients who had undergone suprainguinal vascular surgery were included, and 10.3% suffered postoperative AKI. In multivariable analysis, the number of antihypertensive medications taken on the morning of surgery was independently associated with AKI (P = .026). Compared with patients who took no medication, taking one medication (adjusted odds ratio [aOR], 1.58; 95% confidence interval [CI], 0.68-3.75) and taking two or more medications (aOR, 2.70; 95% CI, 1.13-6.44) were associated with a 1.6-fold and 2.7-fold increased risk of postoperative AKI, respectively. Other predictors of AKI were suprarenal surgery (aOR, 3.37; 95% CI, 1.53-7.44), age (aOR, 2.29 per 10 years; 95% CI, 1.40-3.74), length of surgery (aOR, 1.40 per 1 hour; 95% CI, 1.10-1.76), hemoglobin drop (aOR, 1.37 per 10 g/L; 95% CI, 1.10-1.74), and history of coronary artery disease (aOR, 2.33; 95% CI, 1.08-5.00).

CONCLUSIONS

In patients undergoing major vascular surgery who are treated with chronic antihypertensive therapy, the administration of antihypertensive drugs on the morning of surgery is independently associated with an increased risk of postoperative AKI. Further prospective studies are needed to confirm this finding.

Benzodiazepine administration during adult cardiac surgery: a survey of current practice among Canadian anesthesiologists working in academic centres

BACKGROUND

Benzodiazepines are commonly administered during cardiac surgery because of their limited effect on hemodynamics and presumed role in preventing intraoperative awareness. Recent concerns about an increased risk of delirium with benzodiazepines have resulted in decreased usage in the intensive care unit and in geriatric perioperative practice. Little is known, however, about current benzodiazepine usage in the setting of adult cardiac surgery.

METHODS

We contacted all academic anesthesia departments in Canada to identify practicing attending cardiac anesthesiologists; this group constituted our sampling frame. Information regarding participant demographics, benzodiazepine usage, type, dose, and other administration details were obtained by electronic survey. Responses were analyzed descriptively.

RESULTS

The survey was completed by 243/346 (70%) of cardiac anesthesiologists. Eleven percent of respondents do not administer benzodiazepines. Midazolam was the most commonly used benzodiazepine, with a mean (standard deviation) dose of 4.9 (3.8) mg given to an average patient. When respondents were asked the proportion of patients that they gave benzodiazepines, the response was bimodal. The most common considerations that influenced benzodiazepine use were patient age (73%), patient anxiety (63%), history of alcohol/drug/benzodiazepine use (60%), and the presence of risk factors for intraoperative awareness (44%).

CONCLUSIONS

Benzodiazepine use is common among academic cardiac anesthesiologists in Canada. Nonetheless, heterogeneity exists between individual practices, suggesting clinical equipoise between restrictive and liberal administration of benzodiazepines for cardiac anesthesia. L'administration de benzodiazépines pendant la chirurgie cardiaque chez l'adulte: évaluation de la pratique actuelle des anesthésiologistes canadiens exerçant en milieu universitaire.

Association of Postoperative High-Sensitivity Troponin Levels With Myocardial Injury and 30-Day Mortality Among Patients Undergoing Noncardiac Surgery

IMPORTANCE

Little is known about the relationship between perioperative high-sensitivity troponin T (hsTnT) measurements and 30-day mortality and myocardial injury after noncardiac surgery (MINS).

OBJECTIVE

To determine the association between perioperative hsTnT measurements and 30-day mortality and potential diagnostic criteria for MINS (ie, myocardial injury due to ischemia associated with 30-day mortality).

DESIGN, SETTING, AND PARTICIPANTS

Prospective cohort study of patients aged 45 years or older who underwent inpatient noncardiac surgery and had a postoperative hsTnT measurement. Starting in October 2008, participants were recruited at 23 centers in 13 countries; follow-up finished in December 2013.

EXPOSURES

Patients had hsTnT measurements 6 to 12 hours after surgery and daily for 3 days; 40.4% had a preoperative hsTnT measurement.

MAIN OUTCOMES AND MEASURES

A modified Mazumdar approach (an iterative process) was used to determine if there were hsTnT thresholds associated with risk of death and had an adjusted hazard ratio (HR) of 3.0 or higher and a risk of 30-day mortality of 3% or higher. To determine potential diagnostic criteria for MINS, regression analyses ascertained if postoperative hsTnT elevations required an ischemic feature (eg, ischemic symptom or electrocardiography finding) to be associated with 30-day mortality.

RESULTS

Among 21 842 participants, the mean age was 63.1 (SD, 10.7) years and 49.1% were female. Death within 30 days after surgery occurred in 266 patients (1.2%; 95% CI, 1.1%-1.4%). Multivariable analysis demonstrated that compared with the reference group (peak hsTnT <5 ng/L), peak postoperative hsTnT levels of 20 to less than 65 ng/L, 65 to less than 1000 ng/L, and 1000 ng/L or higher had 30-day mortality rates of 3.0% (123/4049; 95% CI, 2.6%-3.6%), 9.1% (102/1118; 95% CI, 7.6%-11.0%), and 29.6% (16/54; 95% CI, 19.1%-42.8%), with corresponding adjusted HRs of 23.63 (95% CI, 10.32-54.09), 70.34 (95% CI, 30.60-161.71), and 227.01 (95% CI, 87.35-589.92), respectively. An absolute hsTnT change of 5 ng/L or higher was associated with an increased risk of 30-day mortality (adjusted HR, 4.69; 95% CI, 3.52-6.25). An elevated postoperative hsTnT (ie, 20 to <65 ng/L with an absolute change ≥5 ng/L or hsTnT ≥65 ng/L) without an ischemic feature was associated with 30-day mortality (adjusted HR, 3.20; 95% CI, 2.37-4.32). Among the 3904 patients (17.9%; 95% CI, 17.4%-18.4%) with MINS, 3633 (93.1%; 95% CI, 92.2%-93.8%) did not experience an ischemic symptom.

CONCLUSIONS AND RELEVANCE

Among patients undergoing noncardiac surgery, peak postoperative hsTnT during the first 3 days after surgery was significantly associated with 30-day mortality. Elevated postoperative hsTnT without an ischemic feature was also associated with 30-day mortality.

Surgically placed abdominal wall catheters on postoperative analgesia and outcomes after living liver donation

Living donor liver resections are associated with significant postoperative pain. Epidural analgesia is the gold standard for postoperative pain management, although it is often refused or contraindicated. Surgically placed abdominal wall catheters (AWCs) are a novel pain modality that can potentially provide pain relief for those patients who are unable to receive an epidural. A retrospective review was performed at a single center. Patients were categorized according to their postoperative pain modality: intravenous (IV) patient-controlled analgesia (PCA), AWCs with IV PCA, or patient-controlled epidural analgesia (PCEA). Pain scores, opioid consumption, and outcomes were compared for the first 3 postoperative days. Propensity score matches (PSMs) were performed to adjust for covariates and to confirm the primary analysis. The AWC group had significantly lower mean morphine-equivalent consumption on postoperative day 3 [18.1 mg, standard error (SE)=3.1 versus 28.2 mg, SE=3.0; P=0.02] and mean cumulative morphine-equivalent consumption (97.2 mg, SE=7.2 versus 121.0 mg, SE=9.1; P=0.04) in comparison with the IV PCA group; the difference in cumulative-morphine equivalent remained significant in the PSMs. AWC pain scores were higher than those in the PCEA group and were similar to the those in the IV PCA group. The AWC group had a lower incidence of pruritus and a shorter hospital stay in comparison with the PCEA group and had a lower incidence of sedation in comparison with both groups. Time to ambulation, nausea, and vomiting were comparable among all 3 groups. The PSMs confirmed all results except for a decrease in the length of stay in comparison with PCEA. AWCs may be an alternative to epidural analgesia after living donor liver resections. Randomized trials are needed to verify the benefits of AWCs, including the safety and adverse effects.