What's new in anesthesiology

The following represent additions to UpToDate from the past six months that were considered by the editors and authors to be of particular interest. The most recent What's New entries are at the top of each subsection.

CARDIOVASCULAR AND THORACIC ANESTHESIA

Thoracic epidural analgesia for cardiac surgical patients (September 2023)

Neuraxial analgesia is not generally employed for cardiac surgery in the United States due to concerns about spinal epidural hematoma (SEH) after systemic anticoagulation for cardiopulmonary bypass. However, a recent meta-analysis including 51 randomized trials in cardiac surgical patients noted thoracic epidural analgesia (TEA) was associated with shorter lengths of stay in the intensive care unit and hospital (by approximately seven hours and one day, respectively), as well as lower pain scores and rates of delirium, transfusion, arrhythmia, and pulmonary complications [1]. No trial reported a case of SEH. These findings support the use of TEA in cardiac surgical patients. (See "Postoperative care after cardiac surgery", section on 'Neuraxial and regional anesthetic techniques'.)

OBSTETRIC ANESTHESIA

Labor epidural analgesia and risk of emergency delivery (December 2023)

It is well established that contemporary neuraxial labor analgesia does not increase the overall risk of cesarean or instrument-assisted vaginal delivery. However, a new retrospective database study of over 600,000 deliveries in the Netherlands reported that epidural labor analgesia was associated with an increased risk of emergency delivery (cesarean or instrument-assisted vaginal) compared with alternative analgesia (13 versus 7 percent) [2]. Because of potential confounders and lack of detail on epidural and obstetric management, we consider these data insufficient to avoid neuraxial analgesia or change the practice of early labor epidural placement to reduce the potential need for general anesthesia in patients at high risk for cesarean delivery. (See "Adverse effects of neuraxial analgesia and anesthesia for obstetrics", section on 'Effects on the progress and outcome of labor'.)

PATIENT SAFETY

Guidelines for non-operating room anesthesia (NORA) (August 2023)

Challenges in providing anesthetic care for procedures performed in non-operating room locations, such as interventional radiology, transesophageal echocardiography, electrophysiology, magnetic resonance imaging, and computed tomography suites, include distance from the main operating room area, ergonomics, equipment, staffing, and communication issues. Consensus recommendations were developed by the Anesthesia Patient Safety Foundation for Safe Conduct of Non-operating Room Anesthesia (NORA) [3]. These include: guidelines for preprocedure evaluation and postanesthesia recovery; standards for anesthesia and monitoring equipment, supplies, and medications; need for interdisciplinary communication during the procedure; and immediate availability of emergency equipment, drugs, and crisis manuals. We agree with the recommendations. (See "Considerations for non-operating room anesthesia (NORA)", section on 'Anesthetic challenges in non-operating room locations'.)

PEDIATRIC ANESTHESIA

New guidelines for airway management in infants (January 2024)

Very young children are at higher risk of complications of airway management than children in older age groups; however, guidelines for infants have been lacking. In 2024, the European Society of Anesthesiology and Intensive Care and the British Journal of Anesthesia published joint guidelines for airway management in neonates and infants [4]. A summary of their recommendations appears in the following table (table 1). (See "Airway management for pediatric anesthesia", section on 'Pediatric airway management guidelines'.)

Videolaryngoscopy for endotracheal intubation in critically ill children (January 2024)

Use of videolaryngoscopy (VL) for emergency endotracheal intubation (ETI) in children provides a shared view of the procedure that permits an experienced physician observer to give assistance to the proceduralist. In a multicenter quality study of VL implementation during ETI in pediatric intensive care units with standardized coaching by an attending, over 3500 ETIs were performed with VL, and use of VL increased from 30 percent to 89 percent of ETIs over four years [5]. Compared with direct laryngoscopy, VL was associated with lower adverse events (9 versus 15 percent). The majority of proceduralists were residents or fellows. These findings and prior studies confirm the safety of VL during emergency ETI in children and demonstrate the value of standardized coaching during the procedure for less experienced clinicians. (See "Technique of emergency endotracheal intubation in children", section on 'Video versus direct laryngoscopy'.)

PREOPERATIVE AND POSTOPERATIVE MANAGEMENT

Postoperative noninvasive ventilation or high-flow nasal oxygen for patients with obesity (November 2023)

The optimal postoperative ventilatory strategy for patients with severe obesity has been unclear. In a 2023 network meta-analysis of randomized trials that compared various postoperative noninvasive ventilatory strategies in these patients, high-flow nasal oxygen (HFNO) or bilevel positive airway pressure (BiPAP) reduced atelectasis; HFNO, BiPAP, or continuous positive airway pressure (CPAP) reduced postoperative pneumonia; and HFNO reduced length of stay compared with conventional oxygen therapy [6]. For patients with obesity who are hypoxic in the post-anesthesia care unit despite oxygen supplementation and incentive spirometry, we suggest a trial of HFNO, BiPAP, or CPAP prior to considering intubation. (See "Anesthesia for the patient with obesity", section on 'Post-anesthesia care unit management'.)

Glucagon-like peptide 1 (GLP-1) receptor agonists may increase risk of aspiration during anesthesia (July 2023)

Patients who take glucagon-like peptide 1 (GLP-1) receptor agonists (eg, semaglutide, liraglutide) for weight loss or diabetes may be at increased risk of aspiration during anesthesia due to delayed gastric emptying. In 2023, the American Society of Anesthesiologists suggested holding the day-of-surgery or weekly dose of GLP-1 agonists prior to elective surgery because of case reports of aspiration [7]. For patients who have not held their GLP-1 (ie, no drug on day of procedure/surgery for daily dosing, no drug in the week prior to procedure/surgery for weekly dosing), gastric ultrasound can be used to assess for gastric contents or a rapid sequence induction and intubation should be considered. (See "Rapid sequence induction and intubation (RSII) for anesthesia", section on 'Patients taking GLP-1 receptor agonists'.)

SURGICAL CRITICAL CARE

Tranexamic acid for burn wound excision (November 2023)

Randomized trials have established that tranexamic acid (TXA) reduces blood loss and transfusion requirements in various surgical settings, but data in burn surgery are limited. In a meta-analysis of observational studies evaluating intravenous and topical TXA in burn surgery, use of TXA was associated with reductions in blood loss, use of intraoperative transfusion, and number of units transfused but no change in venous thromboembolism or mortality rates [8]. Based on this review and data from other surgical settings, we routinely administer intravenous TXA for burn wound excisions over 20 percent of total body surface area. (See "Overview of the management of the severely burned patient", section on 'Coagulopathy'.)

OTHER ANESTHESIA

Thyroid hormone administration in deceased organ donors (December 2023)

Thyroid hormone administration has been a longstanding component of some organ procurement protocols due to concern that acute hypothyroidism might contribute to hemodynamic instability and left ventricular dysfunction, reducing heart and other organ procurement; however, evidence for the practice has been inconsistent. In a recent trial of 838 hemodynamically unstable, brain-dead donors assigned to receive a levothyroxine infusion or saline placebo, there was little to no difference in number of hearts transplanted or 30-day cardiac graft survival [9]. Recovery of other organs was similarly unaffected. More cases of severe hypertension or tachycardia occurred in the levothyroxine group than in the saline group. Based on these data, we suggest avoiding thyroid hormone administration in deceased organ donors. (See "Management of the deceased organ donor", section on 'Thyroid hormone'.)

Aerosol generation during noninvasive respiratory support modalities (October 2023)

Studies have reported conflicting data as to whether high levels of aerosols are generated when noninvasive ventilation (NIV) or high-flow nasal oxygen (HFNO) is used. In a 2023 systematic review including 12 studies in patients with respiratory infections and 15 studies in healthy volunteers, use of NIV or HFNO was not associated with increased generation of pathogen-laden aerosols compared with controls with unsupported normal or labored breathing, low-flow nasal oxygen, or oxygen or nonrebreather mask [10]. Inconsistency among studies may reflect differences in sampling and detection methodologies and operating room ventilation. Notably, the National Health Service in the United Kingdom has removed mask ventilation, intubation, and extubation from its list of aerosol-generating procedures. (See "Overview of infection control during anesthetic care", section on 'Considerations during aerosol-generating procedures'.)

Effectiveness of intraoperative blood salvage for reducing need for allogenic transfusion (October 2023)

Intraoperative blood salvage is a blood conservation technique in which autologous blood is aspirated, concentrated, washed, and reinfused. A 2023 meta-analysis of randomized trials involving >14,000 patients found that it reduced the need for allogeneic red blood cell transfusions in cardiovascular surgery with or without cardiopulmonary bypass and in major orthopedic hip, knee, or spine surgery [11]. Benefits were uncertain in vascular, cancer, and obstetric surgery. We recommend intraoperative blood salvage in surgical procedures with blood loss >750 mL, particularly if transfusion of allogeneic blood is likely. (See "Surgical blood conservation: Intraoperative blood salvage", section on 'Benefits'.)

Prophylactic steroid administration to prevent postoperative shivering (August 2023)

Postoperative shivering is undesirable since it is uncomfortable, increases metabolic rate, and provokes sympathetic stimulation, which may lead to myocardial ischemia. Several prophylactic medications have been studied; however, their efficacy is uncertain due to significant heterogeneity in dosing regimens and type of surgery. In a 2023 meta-analysis of 25 randomized trials, prophylactic intraoperative administration of either intravenous (IV) dexamethasone or hydrocortisone reduced overall risk of perioperative shivering compared with placebo but not control interventions [12]. Prophylactic IV dexamethasone is frequently used to prevent postoperative nausea and vomiting, and these findings support a potential benefit for the prevention of shivering as well. (See "Perioperative temperature management", section on 'Shivering'.)