Effect of sec-O-glucosylhamaudol on mechanical allodynia in a rat model of postoperative pain

BACKGROUND: This study was performed in order to examine the effect of intrathecal sec-O-glucosylhamaudol (SOG), an extract from the root of the Peucedanum japonicum Thunb., on incisional pain in a rat model. METHODS: The intrathecal catheter was inserted in male Sprague-Dawley rats (n = 55). The postoperative pain model was made and paw withdrawal thresholds (PWTs) were evaluated. Rats were randomly treated with a vehicle (70% dimethyl sulfoxide) and SOG (10 μg, 30 μg, 100 μg, and 300 μg) intrathecally, and PWT was observed for four hours. Dose-responsiveness and ED50 values were calculated. Naloxone was administered 10 min prior to treatment of SOG 300 μg in order to assess the involvement of SOG with an opioid receptor. The protein levels of the δ-opioid receptor, κ-opioid receptor, and μ-opioid receptor (MOR) were analyzed by Western blotting of the spinal cord. RESULTS: Intrathecal SOG significantly increased PWT in a dose-dependent manner. Maximum effects were achieved at a dose of 300 μg at 60 min after SOG administration, and the maximal possible effect was 85.35% at that time. The medial effective dose of intrathecal SOG was 191.3 μg (95% confidence interval, 102.3–357.8). The antinociceptive effects of SOG (300 μg) were significantly reverted until 60 min by naloxone. The protein levels of MOR were decreased by administration of SOG. CONCLUSIONS: Intrathecal SOG showed a significant antinociceptive effect on the postoperative pain model and reverted by naloxone. The expression of MOR were changed by SOG. The effects of SOG seem to involve the MOR.

Recurrent ST segment elevations in a patient with asymptomatic early repolarization during head and neck surgery: implications of vasospastic angina

A 57-year-old woman scheduled for cochlear implant removal exhibited preoperative electrocardiographic findings of early repolarization (ER). Four episodes of transient ST segment elevations during surgery raised suspicion for vasospastic angina (VA). In the post-anesthetic care unit, the patient complained of chest discomfort and received sublingual nitroglycerin with uncertain effect. The patient refused to proceed with postoperative invasive coronary angiography, resulting in inconclusive diagnosis. Intraoperative circumstances limit the diagnosis of VA, which emphasizes the need for further testing to confirm the diagnosis. When VA is suspected in patients with underlying ER, it is reasonable to consider invasive examination to establish the diagnosis and prevent recurrence of VA. If ST changes are observed during surgery in patients with preoperative ER, careful monitoring is recommended. Due to general anesthesia, the absence of patient symptoms limits the definitive diagnosis of those with suspected VA. Therefore, additional postoperative surveillance is recommended.

Pulmonary aspiration during intubation in a high-risk patient: A video clip and clinical implications

We report a case of pulmonary aspiration during induction of general anesthesia in a patient who was status post esophagectomy. Sudden, unexpected aspiration occurred even though the patient had fasted adequately (over 13 hours) and received rapid sequence anesthesia induction. Since during esophagectomy, the lower esophageal sphincter is excised, stomach vagal innervation is lost, and the stomach is flaccid, draining only by gravity, the patient becomes vulnerable to aspiration. As the incidence of perioperative pulmonary aspiration is relatively low, precautions to prevent aspiration tend to be overlooked. We present a video clip showing pulmonary aspiration and discuss the literature concerning the risk of aspiration and its preventive strategies.