Preoperative dexmedetomidine attenuates hemodynamic responses to hydrodissection in patients undergoing robotic thyroidectomy.

PURPOSE: Percutaneous tunneling (hydrodissection) in the neck and anterior chest in patients undergoing robotic thyroidectomy leads to significant hemodynamic responses such as increases in blood pressure and heart rate. We evaluated whether a single preoperative dexmedetomidine injection attenuated hemodynamic responses to hydrodissection by reducing the half-maximal effective concentration (EC50) of remifentanil needed to maintain hemodynamic stability during hydrodissection. METHODS: Forty-one patients undergoing robot-assisted endoscopic thyroidectomy were randomly allocated to one of the two groups-group D (n = 22) and group C (n = 19) patients received dexmedetomidine 1 µg/kg and normal saline for 10 min before anesthetic induction, respectively. The EC50 of remifentanil for hemodynamic stability during hydrodissection was determined using Dixon's up-and-down method with initial dose (4 and 5 ng/mL in groups D and C, respectively). The concentration of remifentanil for consecutive patients in each group was determined by the response of the previous patient, using increments or decrements of 0.5 ng/mL. Hemodynamic stability during hydrodissection was defined as increased systolic blood pressure <20 % of baseline. RESULTS: The EC50 of remifentanil for maintaining hemodynamic stability during hydrodissection was 0.8 ng/mL in group D and 7.3 ng/mL in group C (p = 0.002). CONCLUSIONS: A single preoperative dexmedetomidine injection attenuated hydrodissection-induced hemodynamic responses in patients undergoing robotic thyroidectomy.

The effects of single-dose intravenous dexmedetomidine on hyperbaric bupivacaine spinal anesthesia.

PURPOSE: Dexmedetomidine, a selective α2-adrenoceptor agonist, has analgesic and sedative effects. The purpose of this study was to investigate the effects of small, single-dose intravenous dexmedetomidine administration after hyperbaric bupivacaine spinal anesthesia. METHODS: Sixty adult patients classified as American Society of Anesthesiologists physical status 1 or 2 and scheduled for lower extremity surgery under spinal anesthesia were studied. Patients were randomly assigned to one of three groups and administered hyperbaric intrathecal bupivacaine 12 mg. 5 min after spinal anesthesia, patients in groups 1, 2, and 3 received normal saline 10 ml, dexmedetomidine 0.25 µg/kg, and dexmedetomidine 0.5 µg/kg, respectively, over 10-min intravenous administration. The onset time, maximum block level, two-dermatome sensory regression time, duration of motor and sensory anesthesia, and side effects were assessed. RESULTS: The two-dermatome sensory regression time was significantly increased in groups 2 and 3. The duration of motor and sensory anesthesia was significantly increased in group 3. Onset time, maximum block level, level of sedation, and incidence of hypotension and treatment-needed bradycardia were no different among the groups. CONCLUSION: Single-dose intravenous dexmedetomidine 0.25-0.5 µg/kg, administered 5 min after intrathecal injection of hyperbaric bupivacaine, improved the duration of spinal anesthesia without significant side effects. This method may be useful for increasing the duration of spinal anesthesia, even after intrathecal injection of local anesthetics.

Association between tumor necrosis factor alpha 308G/A polymorphism and increased proinflammatory cytokine release after cardiac surgery with cardiopulmonary bypass in the Korean population.

OBJECTIVES: The G-308A polymorphism of the tumor necrosis factor alpha (TNF-alpha) gene has been suggested to be linked to high TNF promoter activity in in vitro studies. However, there have been some controversies in in vivo studies. This study investigated whether A allele at TNF-308 site is associated with (1) the changes in plasma cytokine levels during and after cardiopulmonary bypass (CPB) and (2) an increased incidence of pulmonary morbidity after CPB. DESIGN: Prospective and observational investigation. SETTING: A university hospital, single institution. PARTICIPANTS: Patients scheduled for cardiac surgery with CPB. INTERVENTION: TNF genotype was determined by the real-time polymerase chain reaction method. IL-6 and TNF-alpha levels were measured by enzyme-linked immunosorbent assay at the following time points: T1, before initiation of CPB; T2, 30 minutes of CPB; T3, 30 minutes after CPB; T4, 2 hours after CPB; and T5, 24 hours after CPB. The oxygen index, serum creatinine level, 24-hour blood loss, intubation time, and length of intensive care unit (ICU) stay were examined. MEASUREMENTS AND MAIN RESULTS: The levels of TNF-alpha in group A (TNF-308GA/AA, n = 25) were higher at T3, T4, and T5 than group G (TNF-308GG, n = 225). The levels of IL-6 showed no statistical difference. The oxygenation index, serum creatinine level, 24-hour blood loss, intubation time, and length of ICU stay showed no statistical difference. CONCLUSIONS: TNF G-308A polymorphism may be associated with excess TNF-alpha secretion in this study and may not be associated with excess IL-6 secretion and postoperative morbidity after CPB.

Severe neurologic manifestations in acute intermittent porphyria developed after spine surgery under general anesthesia: a case report.

Porphyrias are inherited metabolic disorders resulting from a specific enzyme defect in the heme biosynthetic pathway. Porphyrias are induced by various precipitants. Clinical features include abdominal pain, neurologic manifestations, autonomic neuropathy, and mental disturbance. Diagnosis may be delayed because of variable symptoms that mimic other diseases and because of the rarity of of porphyrias. Although most patients with known porphyria can complete anesthesia and surgery safely, undiagnosed porphyric patients are in danger of porphyric crisis due to inadvertent exposure to precipitating drugs and environment. We report a case of a patient who experienced delayed emergence with neurological disturbance after general anesthesia, ultimately diagnosed as acute intermittent porphyria.

Comparison of ramosetron with combined ramosetron and midazolam for preventing postoperative nausea and vomiting in patients at high risk following laparoscopic gynaecological surgery.

OBJECTIVES: This randomized, double-blind study compared the antiemetic efficacy of ramosetron with that of ramosetron combined with midazolam, and investigated whether the timing of midazolam administration affected the incidence of postoperative nausea and vomiting (PONV). METHODS: Nonsmoking female patients undergoing laparoscopic gynaecological surgery were randomized to three groups: group R received intravenous (i.v.) normal saline at induction of anaesthesia and 30 min before the end of surgery; group RM1 received midazolam i.v. at induction of anaesthesia and normal saline i.v. 30 min before the end of surgery; group RM2 received normal saline i.v. at induction of anaesthesia and midazolam i.v. 30 min before the end of the surgery. All patients received 0.3 mg ramosetron i.v. at the end of surgery. Incidence of PONV and need for rescue antiemetics were assessed during the 48-h postoperative period. RESULTS: A total of 126 patients were included in the analyses. There was no significant difference in the incidence of severe nausea, emetic episodes or use of antiemetics among the three groups. The incidence of complete response (no PONV and no rescue antiemetics) was significantly higher in the RM1 (30/41; 73%) and RM2 (30/42; 71%) groups compared with group R (19/43; 44%). CONCLUSIONS: Midazolam given at induction of anaesthesia or at the end of the surgery, combined with ramosetron, was more effective than ramosetron alone in reducing the incidence of PONV.

Aspiration pneumonia caused by fentanyl-induced cough -a case report-.

Although fentanyl-induced cough is generally transient and benign, it can give rise to serious problems in patients to whom increasing intracranial, intraocular or intraabdominal pressures may create dangerous situations. This case demonstrates aspiration pneumonia as a complication, exhibiting severe cough induced by intravenous injection of fentanyl.

Tapia's syndrome following cervical laminoplasty -A case report-.

Tapia's syndrome is the palsy of the 10th and 12th cranial nerves, resulting in ipsilateral paralysis of the vocal cord and tongue. It is a rare complication which is related to the anesthetic airway management and positioning of the patient's head during the surgery. We describe a patient with a postoperative unilateral Tapia's syndrome, after general anesthesia, with uncomplicated endotracheal intubation. The patient's symptoms improved gradually for three months.

Inappropriate elevation of bispectral index values in robot assisted thyroidectomy with electromyographic endotracheal tube -A case report-.

We report a case of an erroneously elevated bispectral index (BIS) during robot assisted thyroidectomy using an electromyographic endotracheal tube (EMG tube), which is safe and useful for laryngeal electromyographic monitoring. Ten minutes after start of the operation, a sudden increase of BIS value up to 98 was noticed. The BIS values were not decreased to < 65 with supplemental anesthetics. The anesthetic method was changed from total intravenous anesthesia to balanced anesthesia. The BIS sensor and monitor were changed and other models were used. These interventions did not alter BIS values. BIS levels remained between 60 and 70 throughout the main procedure and intermittently increased to the mid-90s without any trace of poor signal quality. At the end of the surgery, the BIS values returned to normal range. The patient did not complain of intraoperative recall. Knowledge of potential interference from the use of an EMG tube must be considered when interpreting BIS.

Damage to the cuff of EMG tube at endotracheal intubation by using a lightwand -A case report-.

Electromyogpraphic endotracheal tube (EMG tube) is a new device used to monitor recurrent laryngeal nerve integrity during thyroid surgery. The EMG tube has 2 pairs of electrodes on the surface of silicon-based tube reached to inner space of tube cuff. We experienced an unusual endotracheal tube-related problem from the distinct structural feature of the EMG tube. In this case, we intubated a patient who had difficult airway with the EMG tube using a lightwand. After successful endotracheal intubation, we could not expand the pilot balloon and ventilate the patient effectively. We removed the EMG tube and found that one of electrodes of the EMG tube is bended and made a right angle with the long axis of the tube, and perforated the tube cuff. So we report this case to make anesthesia providers aware that much more attention is needed to use EMG tube during endotracheal intubation.