A Review of Current Literature of Interest to the Office-Based Anesthesiologist.

The American Society of Anesthesiologists, along with experts from 10 national and international collaborating organizations, presents an updated report of the practice guidelines for management of the difficult airway.Comment: This report from the American Society of Anesthesiologists Task Force on Management of the Difficult Airway is an update from the 2013 version, the source of the most recent difficult airway algorithm. At 50 pages, this comprehensive and detailed practice guideline is a major expansion of the previous document, which numbered 19 pages. It is written for all providers of anesthesia care and airway management in both inpatient and ambulatory settings, including dentists who provide general anesthesia, deep sedation, or moderate sedation in office-based settings. Highlights of the 2022 update include expansion of a single algorithm into 2 algorithms, 1 for adult patients and 1 for pediatric patients. Additional infographics condense the content of the algorithms into a form that is quickly understood and suitable for use as a cognitive aid for reference and clinical teaching. Emphasis is placed on being aware of the passage of time during an airway management emergency, limiting the number of intubation attempts, optimization of oxygen and ventilation, and being prepared for anticipated and unanticipated difficult airways. Office-based anesthesia providers will find detailed recommendations for construction of an emergency airway cart, the formulation of an airway emergency plan, and an update of airway management techniques and equipment.The purpose of this nationwide, observational cohort study was to determine the effect of COVID-19 vaccination on postoperative mortality, pulmonary complications, thrombotic complications, readmissions, and hospital lengths of stay among patients undergoing surgery in the United States. Veterans Affairs facilities nationwide were surveyed to compare patients undergoing surgery at least 2 weeks after their second dose of the Pfizer BioNTech or Moderna vaccines to contemporary propensity score matched controls. Primary endpoints were 30-day mortality and postoperative COVID-19 infection. Secondary endpoints were pulmonary or thrombotic complications, readmissions, and hospital lengths of stay. Patients who received COVID-19 vaccination before surgery had fewer COVID-19 infections (0.0% vs 0.3%), pulmonary complications (1.7% vs 3.0%), and thrombotic complications (1.1% vs 1.5%). Mortality and readmissions did not differ between groups.Comment: The authors note this is the first published report to examine the effect of COVID-19 infection on postoperative complications in a cohort of older adults with a significant burden of comorbidity. In addition to showing a benefit from preoperative COVID-19 vaccination, it provides current data to surgeons, institutions, and policy makers striving to achieve evidence-based policies relating to the scheduling of elective surgeries in the setting of a COVID-19 pandemic.Acetaminophen is a frequently used adjunct analgesic in pediatric patients undergoing tonsillectomy and adenoidectomy. This study compared postoperative opioid administration following preoperative intravenous (IV) or oral acetaminophen to test the hypothesis that an IV loading dose approach would provide superior opioid-sparing effects among pediatric surgical patients undergoing tonsillectomy and adenoidectomy.This single-center, double-blind prospective randomized study was conducted in 62 patients ages 3 to 15 years undergoing tonsillectomy and adenoidectomy with or without myringotomy and tube placement between September 2017 and July 2019. Subjects received a single dose of either oral acetaminophen 30 mg/kg with IV placebo (oral group) or IV acetaminophen 15 mg/kg with oral placebo (IV group). Acetaminophen plasma levels were measured at 2 time points to evaluate safety and determine plasma levels. Intraoperative opioid administration and postoperative analgesia were standardized. The primary outcome measure was total opioid administration in the first 24 hours after surgery. Continuous data were not normally distributed and were analyzed using the Wilcoxon rank sum test and the Hodges-Lehman estimator of the median difference. Clinical significance was defined as a difference of 100 μg/kg IV morphine equivalents per day. No difference was found in the percentage of patients with severe pain. No statistically significant difference was observed in postoperative opioid usage between the groups. Postoperative plasma acetaminophen levels were higher in the oral group than the IV group. Safety thresholds for plasma acetaminophen were below the toxic threshold in all patients. Data from this study suggest an oral loading dose of 15 mg/kg may provide more consistent serum acetaminophen levels at lower cost compared with a standard IV loading dose.Comment: The authors note that IV acetaminophen is ∼20 times more expensive than an equivalent oral dose. In addition, the IV acetaminophen formulation cannot be divided easily among patients, and the cost of drug waste is high compared to oral dosing. Previous studies showed higher postoperative plasma levels with IV acetaminophen; however, a lower oral dose was used compared with this study. Conversion to oral acetaminophen may provide equal or better analgesia at significant cost savings.Peripheral venous cannulation (PVC) is a commonly performed invasive medical procedure. Topical treatments such as the eutectic mixture of local anesthetics (EMLA) attenuate the associated pain but are limited by requiring up to 1 hour of application before becoming effective. The Coolsense (Coolsense Medical Ltd) pain numbing applicator is a new device that uses a cryoanalgesic means to anesthetize skin within seconds. Coolsense is being increasingly used for cannulation, but comparative studies are lacking. This study recruited 64 healthy adult volunteers for this open-label, 2-sequence, 2-period randomized crossover trial. Participants had two 20-gauge venous cannulas inserted, 1 on the dorsum of each hand. Each cannulation attempt was preceded by treatment with Coolsense or an EMLA patch containing 2.5% lidocaine and 2.5% prilocaine. The primary outcome was participant pain assessed using a 0-10 numerical pain rating scale. Secondary outcomes were participant satisfaction scores on a 0-10 scale, treatment preference, and failed cannulation attempts. Participants were randomly assigned to either the Coolsense/EMLA or EMLA/Coolsense sequencing. All participants completed the trial. The pooled mean paired difference of the numerical pain rating scale was −1.84 in favor of EMLA (P < .001). The pooled mean paired difference for satisfaction score was 2.26 higher with EMLA (P < .001). Most participants preferred EMLA over Coolsense (P < .001). There was no significant difference regarding failed cannulation between the 2 treatments (P = .14). Among healthy individuals undergoing elective PVC, EMLA was associated with reduced pain and increased satisfaction, and was the preferred treatment compared to Coolsense.Comment: Coolsense is a cryoanalgesic device that uses an electronic applicator to cool the skin prior to needle penetration. Using the gate-control theory of pain as its conceptual basis, this product was initially developed to obtund the discomfort of hypodermic insulin injection and therapeutic botulinum toxin injection. In contrast to the use of EMLA, conduction block of afferent pain fibers occurs with the use of the product. This study is the first to compare this device with EMLA application in the setting of IV cannulation. The crossover design of this study adds to the strength of the results despite the relatively low number of subjects because each subject serves as their own control. Given the clear pattern of patient preference seen in this study, the authors recommend continued use of EMLA prior to IV cannulation, despite the ease and efficiency of cryogenic stimulation.Summaries and comments provided byMark A. Saxen, DDS, PhDIndiana Office-Based AnesthesiaIndiana University School of DentistryIndianapolis, IN