[Satisfactory Sedation for a Morbidly Obese Woman by Dexmedetomidine Dosed on the Basis of Total Body Weight under Spinal Anesthesia ; A Case Report].

A 45-year-old morbidly obese woman (body mass index 51.9) was scheduled for right knee arthroscopic synovectomy. We selected spinal anesthesia in order to avoid difficult ventilation or intubation during anes- thetic induction of general anesthesia. As she strongly requested unawareness during operation, we decided to sedate her with dexmedetomidine(DEX), a sedative drug which has little possibility to cause upper airway obstruction and respiratory depression. Dose of DEX was determined based on total body weight (TBW) instead of ideal body weight To achieve adequate sedation, DEX was titrated by monitoring Ramsay sedation score (RSS), and was discontinued 10 minutes before the end of operation. She was well sedated dur- ing the operation but developed minimal upper airway obstruction and respiratory depression. She showed a good recovery profile when discharged from the oper- ating room. She was very satisfied with the anesthetic management The similar patient's satisfaction was also obtained at the opposite knee joint operation per- formed using the same anesthetic management Conse- quently, DEX infusion based on TBW appears to be suitable to sedate a morbidly obese patient.

Are serum S100beta proteins and neuron-specific enolase predictors of cerebral damage in cardiovascular surgery?

OBJECTIVE: To examine whether serum concentrations of S100beta protein and neuron-specific enolase (NSE) are predictors of cerebral damage in cardiovascular surgery. DESIGN: Prospective clinical study. SETTING: University hospital. PARTICIPANTS: Eighteen patients with conventional cardiopulmonary bypass (CPB), 7 with selective cerebral perfusion (SCP), and 3 volunteers (blood samples). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: S100beta and NSE were measured in the blood obtained at 7 time points during and after operation. The concentrations of these markers in the blood from the surgical field and the cell-saver device, and the influence of graded hemolysis (in vitro) on the concentrations of these proteins were also examined. The mean values of S100beta in the CPB group (2.08 +/- 2.00 ng/mL) and the SCP group (1.46 +/-0.77 ng/mL) were highest after aortic declamping and after termination of SCP, respectively. The mean values of NSE in the CPB group (29.1 +/- 14.0 ng/mL) and the SCP group (31.2 +/- 13.6 ng/mL) were highest after termination of CPB and at the end of the operation, respectively. Three patients suffered from cerebral complications, but the elevation of these markers during operation was indistinguishable from those in the other patients. Peak concentrations of S100beta protein in the CPB group and NSE in the SCP group were correlated with the duration of aortic cross-clamping and CPB, respectively. S100beta protein and NSE concentrations in the blood from the surgical field were significantly larger than those in arterial blood, whereas the concentrations in the blood in the cell-saving device were not elevated. The concentration of S100beta protein was not influenced by the extent of hemolysis, whereas NSE concentration was markedly elevated by hemolysis. CONCLUSION: A large part of the increases in S100beta protein and NSE during CPB and SCP is not attributed to neuronal damage, but to contamination with the blood from the surgical field. To determine whether these markers are useful to predict neurologic complications, it will be necessary to exclude contamination from the surgical field as observed in the present study.