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.

ACUTE AND CHRONIC PAIN

CDC updates opioid prescribing guidelines (November 2022)

The United States Centers for Disease Control and Prevention (CDC) has published a new guideline for prescribing opioids for acute, subacute, and chronic pain, updating their 2016 guideline (table 1). The guideline is intended for clinicians who prescribe opioids to outpatients ≥18 years of age and does not apply to pain related to sickle cell disease, cancer, palliative care, or end of life care [1]. (See "Use of opioids in the management of chronic non-cancer pain", section on 'Opioid therapy in the context of the opioid epidemic'.)

AIRWAY MANAGEMENT

Video laryngoscopy for emergency intubation in adults (December 2022)

Video laryngoscopes (VLs) are rigid devices that allow glottic visualization without a direct line of sight, and they are increasingly being used for rapid sequence intubation in the emergency department. In a meta-analysis of 222 trials in adults (most in the elective surgery setting), Macintosh-style, hyperangulated, and channelled VLs all reduced the rate of failed intubation, increased first-pass attempt success, improved the glottic view, and reduced peri-intubation hypoxia compared with a direct laryngoscope (DL) [2]. Given these findings, we suggest using a VL, if available, instead of a DL when laryngoscopy is indicated for emergency intubation. (See "Overview of advanced airway management in adults for emergency medicine and critical care", section on 'Choice of laryngoscopy technique'.)

CARDIOVASCULAR AND THORACIC ANESTHESIA

Guidelines to prevent acute kidney injury during adult cardiac surgery (January 2023)

Cardiac surgery with cardiopulmonary bypass (CPB) is associated with risk for acute kidney injury. The Society of Thoracic Surgeons/Society of Cardiovascular Anesthesiologists/American Society for Extracorporeal Technology have developed a new guideline to mitigate renal risk in this setting [3]. Recommendations include avoiding hyperthermia (body temperature >37°C) and ensuring adequate pump flow that maintains estimated oxygen delivery index (DO₂i) at a high threshold (>300 mL/minute/m²) during CPB. We agree with these recommendations. (See "Management of special populations during cardiac surgery with cardiopulmonary bypass".)

Prothrombin complex concentrate versus plasma for coagulopathy and bleeding after cardiopulmonary bypass (September 2022)

Unactivated prothrombin complex concentrate (PCC) is used to rapidly correct warfarin anticoagulation. Observational studies have described off-label use of PCC to treat surgical coagulopathic bleeding, but supporting data are limited. One randomized trial compared administration of PCC 15 International Units/kg with fresh frozen plasma (FFP) 10 to 15 mL/kg in 100 patients who had excessive microvascular bleeding with prothrombin time (PT) >16.6 seconds and international normalized ratio (INR) >1.6 after cardiac surgery with cardiopulmonary bypass [4]. Overall efficacy and safety were comparable between PCC and FFP, and patients receiving PCC had improved correction of PT and INR. Before considering administration of PCC or FFP, we treat other causes of intractable bleeding (eg, surgical sources, thrombocytopenia, low fibrinogen levels, platelet dysfunction). (See "Achieving hemostasis after cardiac surgery with cardiopulmonary bypass", section on 'Prothrombin complex concentrate (PCC) products'.)

Guidelines for perioperative management of patients with pulmonary hypertension and right heart failure (September 2022)

Pulmonary hypertension with right heart failure is a risk factor for perioperative morbidity and mortality. In a recently published consensus statement, the International Society for Heart and Lung Transplantation recommended a multidisciplinary approach to preoperative assessment to ensure that the indication and benefits of surgery are reasonable and that the patient's condition is optimal for surgery [5]. Intraoperative considerations include use of invasive monitoring for higher-risk cases, use of slowly titrated epidural or spinal neuraxial anesthesia as appropriate, and induction of general anesthesia with etomidate with appropriate use of vasopressors. Vigilant postoperative monitoring is necessary for early recognition and treatment of complications. (See "Anesthesia for noncardiac surgery in patients with pulmonary hypertension or right heart failure", section on 'Risks of anesthesia and surgery'.)

PREOPERATIVE AND POSTOPERATIVE MANAGEMENT

Updated guidance for preoperative COVID-19 testing (February 2023)

In December 2022 the American Society of Anesthesiologists and the Anesthesia Patient Safety Foundation published a joint statement updating recommendations about preoperative COVID-19 testing [6]. Instead of routine preoperative universal COVID-19 testing in asymptomatic patients, they now recommend preoperative screening for symptoms of COVID-19 and contact with patients with COVID-19, robust infection control measures, and targeted testing taking into account community incidence of COVID-19 and facility ability to distance patients. Asymptomatic screening may be associated with unnecessary procedure delays and additional cost and is unlikely to provide benefit if infection prevention strategies are used. (See "COVID-19: Perioperative risk assessment and anesthetic considerations, including airway management and infection control", section on 'Preoperative screening and testing'.)

Timing of surgery after ischemic stroke (December 2022)

The risk of perioperative stroke is increased in patients with a prior ischemic stroke, though optimal timing of surgery after stroke is unclear. In a database study including nearly six million patients, the risk of postoperative ischemic stroke was increased eightfold in patients who had a stroke within 30 days before surgery, compared with those who never had a stroke [7]. The risk of recurrent stroke decreased and leveled off for surgery between 60 and 90 days after stroke, but remained elevated. The timing of surgery in patients with prior ischemic stroke should consider the risk of recurrent stroke and the risk of delaying surgery. We suggest delaying elective surgery for at least three months, and if possible up to nine months, after a stroke to reduce the risk of recurrence. (See "Perioperative stroke following noncardiac, noncarotid, and nonneurologic surgery", section on 'Timing of surgery after ischemic stroke'.)

Markers of liver fibrosis and risk of surgical mortality (December 2022)

The benefit of checking preoperative liver biochemistries in healthy individuals is uncertain because most patients with abnormal biochemistries do not have advanced liver disease. However, emerging data suggested that an elevated FIB-4 score, which consists of age, aminotransferases, and platelet count, may be associated with increased surgical mortality. In a large cohort study of individuals without known liver disease, a preoperative FIB-4 score ≥2.67 (defined as the threshold for advanced fibrosis) was associated with increased risk of intraoperative mortality, mortality during hospitalization, and 30-day mortality [8]. While biochemical markers of liver disease may have a future role for assessing surgical risk, additional studies are needed to confirm these findings. (See "Assessing surgical risk in patients with liver disease", section on 'Screening for liver disease before surgery'.)

Preoperative exercise training before lung cancer resection surgery (December 2022)

Some prehabilitation programs include physical exercise training before elective major surgery. In a meta-analysis of 10 randomized trials with over 600 total patients undergoing open or video-assisted resection of non-small cell lung cancer, preoperative aerobic, resistance, and/or respiratory muscle training reduced the risk of postoperative pulmonary complications by over 50 percent and reduced postoperative hospital stay by more than two days [9]. Similar results were noted in previous systematic reviews. Preoperative exercise training likely has benefits in selected patients undergoing lung resection, particularly those with poor functional capacity. (See "Overview of prehabilitation for surgical patients", section on 'Physical exercise programs'.)

Risk factors for mortality after major surgery in older adults (October 2022)

Multiple factors contribute to the increased perioperative risk associated with older age. In a prospective study of nearly 1200 major surgeries among community-living adults ≥65 years old (mean age 79 years), one-year mortality rates were higher in those with frailty (28 versus 6 percent) or probable dementia (33 versus 12 percent), and in those requiring urgent surgery (22 versus 7 percent) [10]. These findings add to other evidence suggesting that absolute age alone has only a modest impact on postoperative outcomes and should not be used as a sole criterion to guide decisions regarding patient selection for a major procedure. (See "Anesthesia for the older adult", section on 'Preanesthesia consultation'.)

OTHER ANESTHESIA

Guidelines for reducing the environmental impact of perioperative care (March 2023)

Avoiding unnecessary resource use and controlling emissions are important approaches to reduce the environmental impact of perioperative care. Updated Canadian Anesthesiologists' Society guidelines re-emphasize specific strategies that include choosing reusable, reprocessable equipment rather than single-use disposable items, recycling materials when feasible, and responsibly using inhalation anesthetic agents (eg, low fresh gas flow during delivery; minimizing use of desflurane and nitrous oxide; selecting alternative techniques such as total intravenous anesthesia [TIVA] or neuraxial or regional anesthetic approaches when appropriate) [11]. (See "Environmental impact of perioperative care", section on 'Managing supplies, equipment, and medications'.)

New guideline for managing perioperative patients on cannabis and cannabinoids (January 2023)

The American Society of Regional Anesthesia and Pain Medicine (ASRA) has developed a new guideline for managing the perioperative patient on cannabis and cannabinoids, given the increasing number of such patients [12]. Among the recommendations, all patients reporting chronic use of cannabinoids should be counseled on the potential risks of continued perioperative use. Elective surgery should be postponed in patients with altered mental status or impairment of decision-making capacity due to acute cannabis intoxication; even in the absence of overt intoxication, a delay of at least two hours after smoking cannabis is recommended to avoid a possible increased risk of myocardial infarction. (See "Anesthesia for patients with substance use disorder or acute intoxication", section on 'Cannabis (marijuana)'.)

New anesthesia society guidelines for neuromuscular blockade (January 2023)

Both the American Society of Anesthesiologists (ASA) and European Society of Anaesthesiology and Intensive Care (ESAIC) have published new guidelines on the management of neuromuscular blockade during anesthesia [13,14]. In addition to other recommendations, both guidelines strongly recommend using quantitative neuromuscular monitoring (eg, electromyography or accelerometry) rather than qualitative assessment and confirming a train-of-four ratio ≥0.9 before extubation. They also recommend using sugammadex for reversal rather than neostigmine for patients who have received rocuronium or vecuronium and who have residual block at or deeper than a train-of-four ratio of 0.4. Our recommendations are consistent with these guidelines. (See "Monitoring neuromuscular blockade", section on 'When and how to monitor neuromuscular blockade' and "Clinical use of neuromuscular blocking agents in anesthesia".)

Low risk of systemic complications after cataract surgery (November 2022)

In a retrospective cohort study of Medicare beneficiaries, the group undergoing cataract surgery had a lower incidence of systemic complications within seven days of surgery than those undergoing other types of elective low-risk outpatient procedures (7.7 versus 13 to 52 percent) [15]. An anesthesia provider was present for most cataract procedures, but systemic complications remained low in the six percent that had no anesthesia care (7.4 percent in this group). These data underscore the low risk of systemic complications in patients undergoing cataract surgery, even without anesthesia care. (See "Anesthesia for elective eye surgery", section on 'Systemic complications'.)