Inappropriate Implantable Cardioverter-Defibrillator Therapy During Total Hip Arthroplasty.

Electromagnetic interference (EMI) is a known risk factor for triggering inappropriate therapy from implantable cardioverter-defibrillators (ICDs). Recommendations from the American Society of Anesthesiologists focus on EMI when using monopolar electrocautery for supraumbilical surgeries. Infraumbilical surgeries are not considered high risk for EMI; thus, no magnet must be applied routinely to prevent inappropriate ICD therapy intraoperatively. We describe a case of a 71-year-old woman who presented for left total hip arthroplasty with a history of an ICD. The patient's history was significant for non-ischemic cardiomyopathy. Monopolar electrocautery was used, and the level of the surgery was below the umbilicus. She experienced nine inappropriate ICD therapies intraoperatively with no long-term sequelae. The location of the electrocautery dispersion pad may have contributed to inappropriate therapies. Thus, the dispersion pad location should be considered when deciding whether to suspend anti-tachycardia functions intraoperatively. We present a case of inappropriate therapy from an ICD and make a recommendation for preventing such events.

A Positive Cocaine Urine Toxicology Test and the Effect on Intraoperative Hemodynamics Under General Anesthesia.

BACKGROUND: Cocaine has a short biological half-life, but inactive urine metabolites may be detectable for a week following use. It is unclear if patients who test positive for cocaine but have a normal electrocardiogram and vital signs have a greater percentage of hemodynamic events intraoperatively. METHODS: A total of 328 patients with a history of cocaine use who were scheduled for elective noncardiac surgery under general anesthesia were enrolled. Patients were categorized into cocaine-positive versus cocaine-negative groups based on the results of their urine cocaine toxicology test. The primary aim of this study was to evaluate whether asymptomatic cocaine-positive patients had similar percentages of intraoperative hemodynamic events, defined as (1) a mean arterial blood pressure (MAP) of <65 or >105 mm Hg and (2) a heart rate (HR) of <50 or >100 beats per minute (bpm) compared to cocaine-negative patients. The study was powered to assess if the 2 groups had an equivalent mean percent of intraoperative hemodynamic events within specific limits using an equivalence test of means consisting of 2 one-sided tests. RESULTS: The cocaine-positive group had a blood pressure (BP) that was outside the set limits 19.4% (standard deviation [SD] 17.7%) of the time versus 23.1% (SD 17.7%) in the cocaine-negative group (95% confidence interval [CI], 0.5-7.0). The cocaine-positive group had a HR outside the set limits 9.6% (SD 16.2%) of the time versus 8.2% (SD 14.9%) in the cocaine-negative group (95% CI, 4.3-1.5). Adjusted for age, sex, body mass index (BMI), smoking status, and the presence of comorbid hypertension, renal disease, and psychiatric illness, the cocaine-positive and cocaine-negative patients were similar within a 7.5% margin of equivalence for MAP data (ß coefficient = 2%, P = .003, CI, 2-6) and within a 5% margin of equivalence for HR data (ß coefficient = 0.2%, P < .001, CI, 4-3). CONCLUSIONS: Asymptomatic cocaine-positive patients undergoing elective noncardiac surgery under general anesthesia have similar percentages of intraoperative hemodynamic events compared to cocaine-negative patients.

Sugammadex versus neostigmine for reversal of rocuronium-induced neuromuscular blockade: A randomized, double-blinded study of thoracic surgical patients evaluating hypoxic episodes in the early postoperative period.

STUDY OBJECTIVE: This objective of this study was to determine if reversal of rocuronium-induced neuromuscular blockade with sugammadex versus neostigmine results in a decreased number of hypoxic episodes in the early postoperative period in patients undergoing thoracic surgery with single lung ventilation. DESIGN: Single-center, randomized, double-blind, two-arm clinical trial. SETTING: Operating room and postanesthesia care unit. PATIENTS: 92 subjects aged ≥18, American Society of Anesthesiologists physical status II-IV, and undergoing a thoracic operation necessitating single lung ventilation. INTERVENTIONS: Subjects received either 2 mg/kg sugammadex or 50 µg/kg neostigmine with 8 µg/kg glycopyrrolate for reversal of moderate neuromuscular blockade. MEASUREMENTS: For the first 90 min postoperatively, all episodes of hypoxia were recorded. Neuromuscular monitoring was performed with acceleromyography (TOF-Watch® SX) and the train of four (TOF) was recorded at 2, 5, 10, and 15 min after administration of the neuromuscular reversal agent. MAIN RESULTS: Subjects who received neostigmine had a median of 1 episode (interquartile range IQR: 0-2.2) of hypoxia versus subjects who received sugammadex who had a median of 0 episodes (IQR: 0-1) (p = 0.009). The mean time to recovery of TOF ≥ 0.9 was significantly faster with sugammadex at 10 min (95% confidence interval CI: 5-15) compared with neostigmine at 40 min (95% CI: 15-53) (p < 0.001). CONCLUSIONS: In thoracic surgical patients necessitating single lung ventilation, sugammadex provides faster reversal of moderate neuromuscular blockade and results in a decreased number of postoperative hypoxic episodes compared with neostigmine.

Apneic Oxygenation During Prolonged Laryngoscopy in Obese Patients: a Randomized, Double-Blinded, Controlled Trial of Nasal Cannula Oxygen Administration.

BACKGROUND: Obese patients have a propensity to desaturate during induction of general anesthesia secondary to their reduced functional residual capacity and increased oxygen consumption. Apneic oxygenation can provide supplemental oxygen to the alveoli, even in the absence of ventilation, during attempts to secure the airway. In this study, we hypothesized that oxygen administration through a nasopharyngeal airway and standard nasal cannula during a simulated prolonged laryngoscopy would significantly prolong the safe apneic duration in obese patients. METHODS: One hundred thirty-five obese patients undergoing non-emergent surgery requiring general anesthesia were randomized to either the control group or to receive apneic oxygenation with air versus oxygen. All patients underwent a standard intravenous induction. For patients randomized to receive apneic oxygenation, a nasopharyngeal airway and standard nasal cannula were inserted. A simulated prolonged laryngoscopy was performed to determine the duration of the safe apneic period, defined as the beginning of laryngoscopy until the peripheral oxygen saturation (SpO2) reached 95%. RESULTS: The oxygen group had a median safe apneic duration that was 103 s longer than the control group. The lowest mean SpO2 value during the induction period was 3.8% higher in the oxygen group compared to the control group. Following intubation, patients in the oxygen group had a mean end tidal carbon dioxide (ETCO2) level that was 3.0 mmHg higher than patients in the control group. CONCLUSIONS: In obese patients, oxygen insufflation at 15 L/min through a nasopharyngeal airway and standard nasal cannula can significantly increase the safe apneic duration during induction of anesthesia.