The Japanese Epidemiologic Study for Perioperative Anaphylaxis, a prospective nationwide study: allergen exposure, epidemiology, and diagnosis of anaphylaxis during general anaesthesia.

BACKGROUND: Diagnosis of perioperative anaphylaxis is often challenging. This study describes the utility of a newly developed tool for identifying patients with a high possibility of anaphylaxis, and aimed to investigate the frequency of anaphylaxis with each drug during the perioperative period in Japan. METHODS: This study included patients with anaphylaxis of Grade 2 or higher severity during general anaesthesia at 42 facilities across Japan in 2019 and 2020. We developed and adopted a unique objective evaluation tool yielding a composite score for diagnosing anaphylaxis, which includes the results of skin tests and basophil activation tests, and clinical scores for perioperative anaphylaxis. The number of cases using each drug and the total number of anaphylaxis cases were investigated to calculate the frequency of anaphylaxis. RESULTS: General anaesthesia was performed in 218 936 cases, which included 55 patients with suspected perioperative anaphylaxis. The developed composite score diagnosed 43 of them with a high probability of anaphylaxis. The causative agent was identified in 32 cases. Plasma histamine levels showed high diagnostic accuracy for anaphylaxis. The top causative agents were rocuronium (10 cases in 210 852 patients, 0.005%), sugammadex (7 cases in 150 629 patients, 0.005%), and cefazolin (7 cases in 106 005 patients, 0.007%). CONCLUSIONS: We developed a composite tool to diagnose anaphylaxis, and found that the combination of tryptase levels, skin testing, and basophil activation testing results and clinical score improved the certainty of anaphylaxis diagnosis. The incidence of perioperative anaphylaxis in our study was 1 in about 5000 general anaesthesia cases. CLINICAL TRIAL REGISTRATION: UMIN000035350.

Enlarged Brachial Plexus Nerve Found During Ultrasound-Guided Peripheral Nerve Block Diagnosed as Charcot-Marie-Tooth Disease: A Case Report.

Ultrasound-guided peripheral nerve block (PNB) has become a popular anesthetic procedure. We report a case of an enlarged brachial plexus nerve noted on ultrasonographic images, as part of PNB, which was diagnosed postoperatively as Charcot-Marie-Tooth disease (CMTD), an inherited neurological disorder of the peripheral nerves. Although nerve enlargement is characteristic of demyelinating diseases such as CMTD, the use of ultrasonography in the diagnosis of neurological disorders is a developing area for neurologists and anesthesiologists can lack knowledge in this emerging field. Unusual nerve presentation on ultrasonographic images during PNB anesthetic procedures should be recognized as being indicative of underlying neurologic disorders. This case highlights that increased awareness of the diagnosis of underlying neurologic disorders by ultrasonography would assist the general practice of PNB in anesthetic medicine. This is especially important as underlying neurological conditions can have important consequences for patient-appropriate anesthesia and may inform best anesthetic practice. A new category, "neurological disorder on ultrasound image", should be introduced to PNB knowledge in anesthetic field.

Anaphylaxis caused by butylscopolamine bromide: a case report.

BACKGROUND: There have been only few reports on butylscopolamine-induced anaphylaxis despite its global usage as an anticholinergic agent for approximately 70 years. We present a case of anaphylaxis caused by butylscopolamine. CASE PRESENTATION: A 63-year-old woman underwent gastrointestinal endoscopic examination. She developed facial cyanosis and hypoxia after intravenous administration of butylscopolamine 10 mg, and her blood pressure was unmeasurable. Her hemodynamic condition recovered after a total of 0.6 mg adrenaline and bolus administration of 100 mg hydrocortisone. One hour after the onset of hypotension, both plasma histamine and serum tryptase were remarkably elevated to 271.7 nmol/L and 174 µg/L, respectively. Skin tests performed 47 days after anaphylaxis showed a positive result only for butylscopolamine among the exposed agents, which was confirmed by basophil activation tests using CD203c and CD63 as markers. CONCLUSION: Butylscopolamine has the potential to cause severe anaphylaxis; hence, identification of the causative agent is important to prevent recurrence of anaphylaxis.

Gastric Fluid Volume Change After Oral Rehydration Solution Intake in Morbidly Obese and Normal Controls: A Magnetic Resonance Imaging-Based Analysis.

BACKGROUND: Although preoperative fluid intake 2 hours before anesthesia is generally considered safe, there are concerns about delayed gastric emptying in obese subjects. In this study, the gastric fluid volume (GFV) change in morbidly obese subjects was investigated after ingesting an oral rehydration solution (ORS) and then compared with that in nonobese subjects. METHODS: GFV change over time after the ingestion of 500 mL of ORS containing 2.5% carbohydrate (OS-1) was measured in 10 morbidly obese subjects (body mass index [BMI], >35) scheduled for bariatric surgery and 10 nonobese (BMI, 19-24) using magnetic resonance imaging. After 9 hours of fasting, magnetic resonance imaging scans were performed at preingestion, 0 min (just after ingestion), and every 30 minutes up to 120 minutes. GFV values were compared between morbidly obese and control groups and also between preingestion and postingestion time points. RESULTS: The morbidly obese group had a significantly higher body weight and BMI than the control group (mean body weight and BMI in morbidly obese, 129.6 kg and 46.3 kg/m, respectively; control, 59.5 kg and 21.6 kg/m, respectively). GFV was significantly higher in the morbidly obese subjects compared with the control group at preingestion (73 ± 30.8 mL vs 31 ± 19.9 mL, P = .001) and at 0 minutes after ingestion (561 ± 30.8 mL vs 486 ± 42.8 mL; P < .001). GFV declined rapidly in both groups and reached fasting baseline levels by 120 minutes (morbidly obese, 50 ± 29.5 mL; control, 30 ± 11.6 mL). A significant correlation was observed between preingestion residual GFV and body weight (r = .66; P = .001). CONCLUSIONS: Morbidly obese subjects have a higher residual gastric volume after 9 hours of fasting compared with subjects with a normal BMI. However, no differences were observed in gastric emptying after ORS ingestion in the 2 populations, and GFVs reached baseline within 2 hours after ORS ingestion. Further studies are required to confirm whether the preoperative fasting and fluid management that are recommended for nonobese patients could also be applied to morbidly obese patients.

A comparison of frontal and occipital bispectral index values obtained during neurosurgical procedures.

UNLABELLED: We placed bispectral index (BIS) sensors on the frontal and occipital areas of neurosurgical patients and compared BIS values obtained from both areas during propofol/fentanyl anesthesia. BIS showed a strong correlation between frontal and occipital montages (r(2) = 0.96; P = 0.03). It may be valid to measure BIS with the sensor on the occipital area if required during frontal neurosurgical procedures. IMPLICATIONS: Bispectral values were positively correlated when recorded from frontal and occipital sensors in patients undergoing clipping of unruptured cerebral aneurysms while anesthetized with propofol and fentanyl.