This Week in Anesthesiology — May 28, 2026

Welcome to This Week in Anesthesiology. This week we're covering 10 notable papers spanning innovations in perioperative management, strategies for high-risk patient populations, and a look at evolving guidelines and future challenges for our specialty. Let's dive in.

First, we’ll look at three studies aimed at refining our perioperative care, from managing diabetes medications to new approaches for both general and regional anesthesia.

The OFACAR Trial

Starting in the journal *Anesthesiology*, a multicenter randomized trial from France challenges the routine use of opioids in cardiac surgery [7]. The OFACAR trial randomized 320 patients undergoing elective cardiac surgery with bypass to either opioid-free anesthesia—using a combination of ketamine, dexamethasone, lidocaine, and magnesium—or a standard technique with sufentanil.

Results

The primary outcome was a composite of major postoperative complications or death within 30 days. This occurred in about 75% of patients in the opioid-free group, compared to about 85% in the standard opioid group. This represents a statistically significant 10% relative risk reduction. Specifically, the opioid-free group saw fewer cardiovascular complications, including less postoperative myocardial damage, and a dramatic reduction in digestive complications. Perhaps most strikingly, there were no deaths in the opioid-free group, compared to six deaths in the control group.

Limitations

However, the authors urge caution. The trial's fragility index was just one, meaning if a single patient in the opioid-free group had a different outcome, the primary result would lose its statistical significance. They appropriately frame these findings as hypothesis-generating, but the strong signal, particularly on mortality, suggests opioid-free anesthesia warrants serious consideration and further study in this high-risk population.

Preventing Rebound Pain

Moving from general to regional anesthesia, a paper in *Anaesthesia* tackles the vexing problem of rebound pain after a peripheral nerve block wears off [9]. Investigators conducted a systematic review and network meta-analysis of 24 randomized trials, including over 2000 patients, to see which pharmacologic strategy works best to prevent it.

Primary Outcome

The analysis found that intravenous dexamethasone had the highest probability of reducing the actual incidence of rebound pain and was judged 'definitely superior' to placebo. For other outcomes, perineural dexamethasone and perineural dexmedetomidine were ranked highest for delaying the onset of rebound pain and prolonging the time until a patient needed their first dose of rescue analgesia. The clinical takeaway is clear: intravenous dexamethasone appears to be a first-line prophylactic drug for preventing rebound pain after single-injection nerve blocks.

Perioperative Diabetes Management

Finally in this section, a paper from the *British Journal of Anaesthesia* provides new data on the perennial question of how to manage glucose-lowering drugs before elective surgery [5]. This was a secondary analysis of the large, international MOPED observational study, looking at over 5,700 patients with type 2 diabetes. The investigators examined whether continuing or stopping metformin, SGLT2 inhibitors, or GLP-1 receptor agonists affected the number of days patients were alive and out of the hospital at 30 days, or DAH-30.

Results

For the nearly 4,000 patients on metformin, those who continued the drug on the day of surgery had a slightly higher DAH-30, spending on average about half a day more at home compared to those who withheld it. While a small effect, it was statistically significant and runs counter to the common practice of holding metformin. For SGLT2 inhibitors and GLP-1 receptor agonists, the study couldn't draw any meaningful conclusions due to smaller patient numbers. This finding on metformin may prompt a re-evaluation of routine preoperative instructions.

Our next theme addresses the management of specific high-risk patient groups, with papers focusing on pediatric surgical patients, those with traumatic brain injury, and obstetric patients experiencing hemorrhage.

Pediatric Sepsis and AKI

A sobering study in *Anesthesia and Analgesia* highlights a 'two-hit' risk factor for mortality in children undergoing surgery [2]. Using a large national database from the United States, researchers performed a retrospective cohort study on over 144,000 children. They found that a severe preoperative infection, such as sepsis or SIRS, was associated with more than double the risk of developing postoperative acute kidney injury.

Mortality Risk

The impact on mortality was even more stark. Preoperative infection alone was associated with a 1.8-times increase in 30-day mortality. Postoperative AKI alone was associated with a 4.6-times increase. But when a child had both a severe preoperative infection and then developed postoperative AKI, the risk of dying within 30 days was nine times higher. This synergistic effect underscores the extreme vulnerability of this population and the need for aggressive, targeted perioperative strategies to prevent and manage kidney injury in septic children.

Hemoglobin in Traumatic Brain Injury

In *Critical Care Medicine*, a study from France investigates whether sex should influence our transfusion triggers in patients with traumatic brain injury [1]. The physiological premise is simple: baseline hemoglobin levels differ by sex. The researchers retrospectively studied over 5,500 TBI patients to see if there was an interaction between admission hemoglobin, sex, and ICU mortality. They found that for every 1 gram per deciliter increase in admission hemoglobin, the odds of ICU mortality decreased by about 31% for all patients. However, when they looked for an interaction with sex, they found none. Causal inference methods confirmed that at any given hemoglobin level, the standardized ICU mortality risk was not different between males and females. The conclusion is that these data do not support implementing sex-differentiated hemoglobin transfusion thresholds in the initial management of TBI patients.

Patient Blood Management in Obstetrics

Broadening the focus on blood management, a narrative review in the *British Journal of Anaesthesia* makes a strong case for implementing Patient Blood Management, or PBM, principles in obstetrics to combat postpartum hemorrhage [6]. The authors, a group of European experts, argue that PBM—which focuses on optimizing a patient's own blood, managing anemia, and preserving blood volume—is urgently needed. The review summarizes recent guidelines and provides practical tools, including an algorithm for managing anemia during pregnancy and a quick-reference chart for PBM strategies during a hemorrhage. This paper serves as a practical guide and a call to action to apply the well-established principles of PBM to improve outcomes for obstetric patients.

Finally, we look at several papers that push us to think bigger, addressing chronic conditions, rare but deadly syndromes, and the very materials and technologies that define our practice.

The Burden of Fibromyalgia

First, a massive systematic review and meta-analysis in *Anesthesia and Analgesia* provides the most comprehensive look yet at the prevalence of fibromyalgia [3]. After reviewing over 21,000 records, the authors synthesized data from nearly 900 studies, covering over 30 million people. They found the pooled global prevalence of fibromyalgia in the general population is about 1.4%, or roughly 1 in 70 people. However, in at-risk subpopulations, the numbers are dramatically higher. For example, prevalence is over 37% in patients with chronic urticaria, nearly 31% in those with interstitial cystitis, and around 20% in patients with celiac disease or inflammatory bowel disease. For clinicians, this is a critical reminder of the high likelihood of encountering fibromyalgia in patients with other chronic inflammatory and pain conditions, which has major implications for perioperative pain management.

New Malignant Hyperthermia Guidelines

Next, the *Canadian Journal of Anaesthesia* publishes a proposed North American approach for diagnosing malignant hyperthermia, which has received endorsement from both the American Society of Anesthesiologists and the Canadian Anesthesiologists' Society [8]. The key update is that genetic testing for the three known causative genes—RYR1, CACNA1S, and STAC3—is now recommended as the first-line test for at-risk individuals. However, the document stresses a crucial limitation: genetic testing has a sensitivity of only up to 70%. This means a negative genetic test does not fully rule out MH susceptibility. For some individuals, the classic caffeine-halothane contracture test may still be necessary to definitively rule out the disorder. This represents a significant shift in the diagnostic algorithm for one of our specialty's most feared complications.

Plastics and AI in the Operating Room

Lastly, we have two forward-looking commentaries. A review in *Anesthesiology* forces us to confront an invisible threat: plastics [4]. The authors detail how the very tools of our trade—syringes, IV tubing, endotracheal tubes, and ventilator circuits—expose both patients and providers to microplastic particles. These exposures occur via intravenous and inhalational routes, bypassing the body's natural defense mechanisms during a period of intense physiologic stress. While direct evidence of harm to human health is still emerging, associations with disease are growing, and animal studies have shown adverse effects. The article is a call to advocate for more research and safer alternatives. And a final commentary from *Annals of Internal Medicine*, titled 'The Human Factor in Clinical AI: Why Technology Alone Is Not Enough,' serves as a timely reminder [10]. As we embrace new technologies, from advanced genetic testing to artificial intelligence, the authors argue that clinician judgment and the human element remain irreplaceable.

If you only have time for one paper this week, make it the OFACAR trial in *Anesthesiology* [7]. It is a large, multicenter randomized controlled trial suggesting that an opioid-free anesthetic in cardiac surgery may reduce major postoperative complications and even mortality. While the authors are rightly cautious and call for more research, it’s a provocative finding that could signal a major shift in practice for a common, high-risk procedure.

Here are the key takeaways from this week in Anesthesiology:

First: In cardiac surgery, a multicenter RCT suggests an opioid-free anesthetic technique may reduce postoperative complications and potentially mortality, though further confirmation is needed [7].

Second: For single-shot peripheral nerve blocks, intravenous dexamethasone appears to be the most effective prophylactic intervention to reduce the incidence of rebound pain [9].

Third: In pediatric surgery, a pre-existing severe infection more than doubles the risk of postoperative AKI, and the combination of these two factors increases 30-day mortality nine-fold, demanding heightened perioperative vigilance [2].

Fourth: New North American guidance positions genetic testing as the first-line investigation for malignant hyperthermia susceptibility, though its limited sensitivity means contracture testing remains an important part of the diagnostic pathway [8].

And Fifth: Contrary to some common practices, continuing metformin on the day of elective surgery was associated with a small but statistically significant increase in days alive and out of the hospital at 30 days in a large observational study [5].

That's your roundup for This Week in Anesthesiology. The full transcript and references are available on the episode page in your AudioScholar library. This is an AI-curated summary — for clinical decisions, always consult primary sources and current guidelines. See you next week.