Effects of Intraoperative Opioid Administration on Postoperative Pain and Pain Threshold: A Randomized Controlled Study.

Fentanyl and short-acting remifentanil are often used in combination. We evaluated the effect of intraoperative opioid administration on postoperative pain and pain thresholds when the two drugs were used. Patients who underwent gynecological laparoscopic surgery were randomly assigned into two groups (15 patients each) to receive either sufficient (group A) or minimum (group B) fentanyl (maximum estimated effect site concentration: A: 7.86 ng/mL, B: 1.5 ng/mL). The estimated effect site concentration at the end of surgery was adjusted to the same level (1 ng/mL). Patients in both groups also received continuous intravenous remifentanil during surgery. The primary outcome was the pressure pain threshold, as evaluated by a pressure algometer 3 h postoperatively. The pressure pain threshold at 3 h postoperatively was 51.1% (95% CI: [44.4-57.8]) in group A and 56.6% [49.5-63.6] in group B, assuming a preoperative value of 100% (p = 0.298). There were no significant differences in pressure pain threshold and numeric rating scale scores between the groups after surgery. The pain threshold decreased significantly in both groups at 3 h postoperatively compared to preoperative values, and recovered at 24 h. Co-administration of both opioids caused hyperalgesia regardless of fentanyl dose.

Anatomical variants of dorsal scapular nerve in relation to the middle scalene muscle in Japanese population.

Dorsal scapular nerve (DSN) block is often performed in Japanese pain clinics to treat neck pain and katakori (a unique symptom in Japanese population characterized by myofascial pain syndromes such as shoulder girdle pain). However, to the best of our knowledge, there are only a few studies regarding anatomical variations in DSN paths around the middle scalene muscle (MSM) in Japanese population. Thus, we conducted a cadaveric study to examine anatomical variations in DSN paths around the MSM in Japanese population.DSN anatomies of 70 adult Japanese cadavers used for research and gross anatomy practice at the Tokai University School of Medicine between 2015 and 2016 were examined.In all cadavers, DSNs originated from the brachial plexus (BP) and innervated the rhomboid major, rhomboid minor, and levator scapulae muscles via the MSM. Two types of DSN paths were observed: piercing-type (piercing the MSM) and anterior-type (running in front of the MSM). We surveyed all 140 sides in 70 Japanese cadavers; of these, 95 sides had piercing-type and 45 had anterior-type paths. Of the 70 cadavers, 42 had piercing-type and 17 had anterior-type paths on both the sides. In 9 cadavers, the left and right sides had piercing-type and anterior-type paths, respectively. In the other 2 cadavers, the right and left sides had piercing-type and anterior-type paths, respectively.We found 2 distinct anatomical variants for DSN paths around the MSM in this Japanese cohort. Our results suggest that the rate of anterior-type DSN path is higher in Japanese population. Therefore, it is necessary to maintain caution while injecting anesthetic agents during a DSN block and the type of DSN should be considered.

Anesthetic Management in Tracheal Dilatation for Severe Tracheal Stenosis.

We report the anesthetic management of a 65-year-old woman with recurrent, severe tracheal stenosis who underwent tracheal dilatation. She had visited the Department of Respiratory Medicine at our hospital for respiratory distress approximately 20 years ago, and had undergone laser ablation under local anesthesia. Because of recurrence and aggravation of respiratory distress, she now presented at the Department of Thoracic Surgery, and was scheduled for surgery. Percutaneous cardiopulmonary support was prepared, and she was sedated with midazolam and dexmedetomidine. Under bronchoscopic guidance, a 5-mm intubation tube was placed directly above the stenosis site. Laser ablation (by argon plasma coagulation) and balloon dilatation were performed, and the tube was replaced with one with a larger diameter, which was subsequently replaced with another with an even larger diameter. Ultimately, a 7-mm tube was placed beyond the stenosis site, and the operation was completed. After restoration of spontaneous respiration and consciousness, the patient was extubated in the operating room and returned to the intensive care unit. In anesthetic management of patients with tracheal stenosis, treatment of hypoxia is important. In this case, we collaborated with the attending physician, clinical engineers, and operating room nurses throughout, and consequently, were able to perform the operation safely.

[Two cases of parturients with intracranical hemorrhage accompanied by seizure].

Intracranial hemorrhage during pregnancy is a rare complication, and it results in a high perinatal mortality rate. We recently encountered 2 cases of intracranial hemorrhage during pregnancy. They underwent cesarean section under general anesthesia. Anesthetic management is difficult because we must avoid hemodynamic change and increasing intracranial pressure, and we have difficult airway management. It is also very difficult to prepare for the prevention before the onset because it develops suddenly, and quick action is important. We must prepare tools of airway management and assemble people. In addition, it is important to use the hypotensive drugs which do not affect placental blood-flow to keep systolic blood pressure around 120-140 if it is necessary to suppress the rise of the blood pressure.