[Successful anesthetic management in a patient with chronic obstructive pulmonary disease (COPD) using dexmedetomidine and combined spinal-epidural anesthesia for low anterior resection of the rectum].

A 70-year-old man with a severe COPD was scheduled for low anterior resection of the rectum because of rectal cancer. After a week of respiratory rehabilitation, respiratory function was much improved. We selected combined spinal-epidural anesthesia (CSEA) and dexmedetomidine to preserve spontaneous breathing. We obtained appropriate sedative and antianxiety effect without causing respiratory depression and hemodynamic changes. Dexmedetomidine was useful for anesthesia for a patient with severe COPD without causing respiratory depression.

Post-operative dexmedetomidine-based sedation after uneventful intracranial surgery for unruptured cerebral aneurysm: comparison with propofol-based sedation.

BACKGROUND: Clinical applications of dexmedetomidine (DEX) for neurosurgical procedures have not been adequately investigated. This study aimed to test the use of DEX infusion, alone or as an adjunct to propofol infusion, as compared to propofol infusion in patients with an unruptured cerebral aneurysm after uneventful intracranial procedures. METHODS: In this retrospective observational study from a single institute, of 184 patients who underwent uneventful intracranial procedures for an unruptured cerebral aneurysm between January 2003 and March 2007, we reviewed 50 managed with DEX-based sedation (DEX alone or as an adjunct to propofol infusion) between April 2005 and March 2007, and 50 managed with propofol-based sedation (propofol alone) between January 2003 and April 2005. With DEX-based sedation, both intubated and extubated patients received DEX infusion at an initial dose of 0.4 µg/kg/h, followed by a maintenance dose of 0.2-0.7 µg/kg/h. Propofol was used in both groups at a dose range of 0.5-5.0 mg/kg/h. Hemodynamic variables, including heart rate (HR) and blood pressure (BP), and adverse events were recorded and compared between the groups. RESULTS: HR during sedation and systolic BP at 2 h after beginning sedation were significantly lower in the DEX group. No serious adverse events were observed. In the DEX group, 66% were sedated in combination with propofol, of whom 94% were intubated. CONCLUSIONS: DEX could be used safely for both intubated and extubated patients following uneventful intracranial procedures for an unruptured cerebral aneurysm, though it significantly reduced HR. Our findings also indicate that it is preferable to add low-dose propofol to DEX for management of intubated patients.

[Case of transient paralysis and paresthesia after epidural blood patch].

A 47-year-old woman with postdural puncture headache suffered from transient paralysis and paresthesia immediately after the epidural blood patch. After one and a half hour, these symptoms disappeared spontaneously. We suspect that the spinal cord or spinal nerve root was transiently pressed by the viscous blood mass, because blood sampling maneuver took a few minutes. With passing of time, the viscous blood spread through the epidural space, and neurological symptoms improved. Although the risks of epidural blood patch are relatively low, we should closely pay attention to unexpected side effects.

[Case of failed spinal anesthesia for cesarean section caused by spinal arachnoid cyst].

A 27-year-old pregnant woman was scheduled for cesarean section under spinal anesthesia. Although there was no trouble in three repeated spinal punctures, the anesthetic effect was insufficient. Then we changed anesthetic management to general anesthesia. There was no postoperative neurological complications related to spinal anesthesia. Postoperatively, spinal arachnoid cyst was found by MRI. The cyst was thought to have caused insufficient analgesic effect of spinal anesthesia in this patient.

Differential effects of isoflurane, halothane, and ketamine on the regional methionine-enkephalinlike immunoreactivity in the mouse brain.

The widely used measurement index for anesthetic potency, minimum alveolar concentration (MAC), is hypothesized to be the sum of the effects on multiple neural systems whose contribution to anesthesia differs depending on the agents used. The present study, which compared the effects of halothane, isoflurane, and ketamine, at equipotent level of anesthesia, on the methionine-enkephalinergic neurons in 9 brain regions, showed a significant difference in the methionine-enkephalin-like immunoreactivity (Met-ENK-like IR) among the anesthetics in each region. The order of the Met-ENK-like IR was: halothane > ketamine > isoflurane in the caudatus putamen; halothane > isoflurane ≊ketamine in the nucleus accumbens and the ventral pallidum; halothane ≊isoflurane > ketamine in the globus pallidus, the nucleus dorsomedialis hypothalami, and the nucleus ventromedialis hypothalami; and halothane > isoflurane > ketamine in the arcuate nucleus, the periaqueductal gray, and the nucleus reticularis parvocellularis. These findings indicate that these three anesthetics affect the methionine-enkephalinergic neurons in the motor and pain controlling pathways in different fashions.