Association of thoracic epidural analgesia with risk of atrial arrhythmias after pulmonary resection: a retrospective cohort study

Exploring postoperative atrial fibrillation after non-cardiac surgery: mechanisms, risk factors, and prevention strategies

Atrial fibrillation (AF) stands as the most prevalent persistent arrhythmia and a common complication after surgical procedures. Although the majority of non-cardiac surgery patients experience postoperative AF (POAF) and the condition is typically self-limited and asymptomatic, its detrimental impact on patient outcomes, prolonged hospitalization, and heightened risk of stroke and overall mortality has become increasingly evident. Of significant concern, POAF emerges as a noteworthy risk factor for stroke, myocardial infarction, and mortality in comparison to patients with non-surgical atrial fibrillation. Multiple studies have corroborated the association between POAF and an elevated risk of stroke and mortality. The development of postoperative atrial fibrillation is multifactorial, with the inflammatory response being a primary contributor; additionally, factors such as hypovolemia, intraoperative hypotension, anemia, trauma, and pain can trigger POAF. Risk factors for POAF in non-cardiac surgery primarily relate to age, hypertension, obesity, prior cardiac disease, obstructive sleep apnea, and male sex. Prophylactic treatment with β-blockers, amiodarone, or magnesium has demonstrated efficacy, but further trials are warranted, especially in high-risk populations. This review provides an account of the incidence rate, pathophysiology, and prognosis of atrial fibrillation after non-cardiac surgery, elucidates the underlying mechanisms of its occurrence, and explores various preventive strategies investigated in this domain.

Acute Pain Burden and Opioid Dose Requirements after Cesarean Delivery in Parturients with Preexisting Chronic Back Pain and Migraine

Introduction

Preexisting chronic pain has been reported to be a consistent risk factor for severe acute postoperative pain. However, each specific chronic pain condition has unique pathophysiology, and it is possible that the effect of each condition on postoperative pain is different.

Methods

This is a retrospective cohort study of pregnant women with preexisting chronic pain conditions (i.e., migraine, chronic back pain, and the combination of migraine + chronic back pain), who underwent cesarean delivery. The effects of the three chronic pain conditions on time-weighted average (TWA) pain score (primary outcome) and opioid dose requirements in morphine milligram equivalents (MME) during postoperative 48 hours were compared.

Results

The TWA pain score was similar in preexisting migraine and chronic back pain. Chronic back pain was associated with significantly greater opioid dose requirements than migraine (12.92 MME, 95% CI: 0.41 to 25.43, P=0.041). Preoperative opioid use (P < 0.001) was associated with a greater TWA pain score. Preoperative opioid use (P < 0.001), smoking (P=0.004), and lower postoperative ibuprofen dose (P=0.002) were associated with greater opioid dose requirements.

Conclusions

Findings suggest women with chronic back pain and migraine do not report different postpartum pain intensities; however, women with preexisting chronic back pain required 13 MME greater opioid dose than those with migraine during 48 hours after cesarean delivery.

Propensity Score Methods: Theory and Practice for Anesthesia Research

Observational data are often readily available or less costly to obtain than conducting a randomized controlled trial. With observational data, investigators may statistically evaluate the relationship between a treatment or therapy and outcomes. However, inherent in observational data is the potential for confounding arising from the nonrandom assignment of treatment. In this statistical grand rounds, we describe the use of propensity score methods (ie, using the probability of receiving treatment given covariates) to reduce bias due to measured confounders in anesthesia and perioperative medicine research. We provide a description of the theory and background appropriate for the anesthesia researcher and describe statistical assumptions that should be assessed in the course of a research study using the propensity score. We further describe 2 propensity score methods for evaluating the association of treatment or therapy with outcomes, propensity score matching and inverse probability of treatment weighting, and compare to covariate-adjusted regression analysis. We distinguish several estimators of treatment effect available with propensity score methods, including the average treatment effect, the average treatment effect for the treated, and average treatment effect for the controls or untreated, and compare to the conditional treatment effect in covariate-adjusted regression. We highlight the relative advantages of the various methods and estimators, describe analysis assumptions and how to critically evaluate them, and demonstrate methods in an analysis of thoracic epidural analgesia and new-onset atrial arrhythmias after pulmonary resection.

Post-thoracotomy dysrhythmia

PURPOSE OF REVIEW

This article reviews and summarizes the pathophysiology, risk factors, and the management of arrhythmias in patients undergoing noncardiac thoracic surgery.

RECENT FINDINGS

Cardiac arrhythmias are common findings in the perioperative period, particularly with increasing age. They often complicate the course of the patient's recovery after operation. The most common postoperative arrhythmia is atrial fibrillation. It requires either a rate or rhythm control strategy, and the need for anticoagulation has to be assessed depending on the duration of the arrhythmia and risk factors. Fortunately, malign sustained ventricular tachyarrhythmias (ventricular tachycardia, ventricular fibrillation) are rare. Acute treatment and, in the absence of a reversible cause, a long-term preventive strategy may be warranted. Transient bradyarrhythmias can be managed by atropine or with temporary pacing.

SUMMARY

Arrhythmias are common after thoracotomy. Physicians treating patients with postoperative arrhythmias should bear in mind that arrhythmia management does not only comprise a specific therapy for the arrhythmia itself, but also includes the correction of transient and correctable predisposing and causative factors.

Potentially modifiable risk factors for atrial fibrillation following lung resection surgery: a retrospective cohort study

Atrial fibrillation is the most frequent arrhythmia after thoracic surgery and is associated with increased hospital costs, morbidity and mortality. In this study, we aimed to identify potentially modifiable risk factors for postoperative atrial fibrillation following lung resection surgery and to suggest possible measures to reduce risk. We retrospectively reviewed the medical records of 4731 patients who underwent lobectomy or more major lung resection over a 6-year period. Patients who developed atrial fibrillation postoperatively and required treatment were included in the postoperative atrial fibrillation group, while the remaining patients were assigned to the non-postoperative atrial fibrillation group. Risk factors for postoperative atrial fibrillation were analysed by multivariate analysis and propensity score matching. Overall, 12% of patients developed postoperative atrial fibrillation. Potentially modifiable risk factors for postoperative atrial fibrillation were excessive alcohol consumption (odds ratio (OR) = 1.48, 95% CI 1.08-2.02, p = 0.0140), red cell transfusion (2.70(2.13-3.43), p < 0.0001), use of inotropes (1.81(1.42-2.31), p < 0.0001) and open (vs. thoracoscopic) surgery (1.59(1.23-2.05), p < 0.0001). Compared with inotrope use, vasopressor administration was not related to postoperative atrial fibrillation. Use of steroids or thoracic epidural anaesthesia did not reduce the incidence of postoperative atrial fibrillation. We conclude that high alcohol consumption, red cell transfusion, use of inotropes and open surgery are potentially modifiable risk factors for postoperative atrial fibrillation. Pre-operative alcohol consumption needs to be addressed. Avoiding red cell transfusion and performing lung resection via video-assisted thoracoscopic surgery may reduce the incidence of postoperative atrial fibrillation and the administration of vasopressors rather than inotropes is preferred.