An acute postoperative intractable hyperventilation after an endoscopic third ventriculostomy.

This report describes a rare case of postoperative hyperventilation attack after an endoscopic third ventriculostomy in a 46-year-old woman. About 60 min after the termination of the operation, an intractable hyperventilation started with respiratory rate of 65 breaths/min and EtCO(2), 16.3 mm Hg. Sedation with benzodiazepine, thiopental sodium, fentanyl, and propofol/remifentanil infusion was tried under a rebreathing mask at a 4 L/min of oxygen. With aggressive sedative challenges, ventilation pattern was gradually returned to normal during the 22 hrs of time after the surgery. A central neurogenic hyperventilation was suspected due to the stimulating central respiratory center by cold acidic irrigation solution during the neuroendoscopic procedure.

The optimal volume of 0.2% ropivacaine required for an ultrasound-guided stellate ganglion block.

BACKGROUND: This study was performed to find the optimal volume of local anesthetics needed for a successful ultrasound-guided stellate ganglion block (SGB) to treat head and neck pathology. METHODS: Fifteen female and fourteen male sensory-neural hearing loss patients received 4 times SGBs with 0.2% ropivacaine in volumes of 6, 4, 3 and 2 ml at 1 to 3 day intervals. Using the transverse short-axis view of the neck that showed Chassaignac's tubercle at the C6 level, a 25-gauge, and 4 cm needle was inserted via the lateral paracarotid approach with out-of-plane targeting between the prevertebral fascia and the ventral surface of longus colli muscle (subfascial injection). A successful block was confirmed with the onset of ptosis (Horner's syndrome). RESULTS: There were no significant statistical differences between the presence of Horner's syndrome and the volume of local anesthetics given. However, Horner's syndrome was present in all trials for the 4 ml and 6 ml groups. Six (20.7%) and three out (10.4%) of twenty-nine trials in the 2 ml and 3 ml groups, respectively, failed to elicit Horner's syndrome. The duration of action was significantly different in the 2 ml group compared to that of the 6 ml group, but there was no significant difference between the other groups, including the 4 ml vs. 6 ml groups. The side effects were not different between the groups. CONCLUSIONS: This data suggests that the optimal volume of 0.2% ropivacaine for ultrasound-guided SGB to treat the head and neck pathology in daily practice is 4 ml.