[General Anesthesia Using Remifentanil for Cesarean Section in a Parturient with Marfan Syndrome Associated with Heart Failure due to Severe Mitral Regurgitation].

A 24-year-old woman with Marfan syndrome was scheduled for cesarean section in order to avoid progression of heart failure due to severe mitral regurgitation and aortic dissection during labor. Cesarean section was performed under general anesthesia using remifentanil. Anesthesia was induced and maintained with remifentanil (0.1-0.3 µg x kg(-1) x min(-1)) and continuous administration of propofol (target-controlled infusion, 2-3 ng x ml(-1)). The trachea was intubated without a significant hemodynamic change. The patient's systolic blood pressure was maintained between 90 and 120 mmHg during surgery. Intraoperatively, we conducted a transesophageal echocardiography examination, and no remarkable change was seen in the severity of mitral regurgitation and the size of an ascending aorta. An infant was delivered 6 minutes after anesthesia induction. The Apgar scores were 4 at 1 min, 5 at 5 min and 8 at 10 min. Postoperative course was uneventful. We conclude that remifentanil can be used successfully to manage cesarean section of a parturient with Marfan syndrome associated with heart failure due to severe mitral regurgitation under general anesthesia.

Magnesium sulfate attenuates tourniquet pain in healthy volunteers.

PURPOSE: Preoperative administration of an N-methyl-D-aspartate (NMDA) receptor antagonist has been shown to attenuate tourniquet-induced blood pressure increase under general anesthesia, suggesting that the mechanism of this blood pressure increase includes NMDA receptor activation. The attenuation of this increase may be associated with the pain relief induced by NMDA receptor antagonism. We tested the hypothesis that magnesium sulfate, an NMDA receptor antagonist, attenuates tourniquet pain. METHODS: Twenty-four healthy volunteers were randomly assigned to four groups (n = 6 each): control (normal saline), M1 (magnesium, 1 g), M2 (magnesium, 2 g), and M4 (magnesium, 4 g). Normal saline or magnesium solution was given intravenously over a 15-min period, in a double-blind fashion, before tourniquet inflation, which was continued for 60 min or until the "pain score" (0 = no pain, 100 = highest tolerable pain) reached 100. Pain scores were recorded before and every 5 min during tourniquet inflation. If subjects reported a pain score of 100 before the end of the 60-min period, we adopted a pain score of 100 for the remaining period. RESULTS: The duration of tourniquet inflation in the M4 group was significantly longer than that in the control group (54.3 ± 8.3 vs. 42.9 ± 9.9 min, P = 0.03). Pain scores in the M4 group were significantly lower than those in the control group from 10 through 50 min after the start of tourniquet inflation. The area under the curve for pain scores in the M4 group was significantly smaller than the areas in the other groups. CONCLUSION: Magnesium sulfate, 4 g, significantly attenuated tourniquet pain in healthy awake volunteers, suggesting that NMDA receptor activation is involved in tourniquet pain.

[The efficacy of the "BURP" maneuver during laryngoscopy and training period necessary for residents in anesthesiology].

BACKGROUND: The "BURP" maneuver (back, upward, right lateral, pressure) improves the visualization of the larynx for experienced anesthesiologists during orotracheal intubation in patients with difficult airway. We investigated whether this maneuver has same efficacy for inexperienced residents in anesthesiology. METHODS: We compared the visual condition of the larynx using "BURP" maneuver, back pressure or no maneuver between 37 residents and 16 staff anesthesiologists in 132 patients receiving general anesthesia. Additionally, we investigated the effects of residents' training period on their advancements in visualization of the larynx. RESULTS: The "BURP" maneuver significantly improved the visualization with laryngoscope. The third month of the training period developed visualization in comparison with those of the first month. The visualization in experiencing 31-35 patients was significantly improved than experiencing 1-10 patients. CONCLUSIONS: We concluded that "BURP" maneuver was effective even for inexperienced residents. More than two months were required for the residents to develop laryngoscopy skill.

Minimum alveolar concentrations of sevoflurane for maintaining bispectral index below 50 in children.

OBJECTIVE: To determine minimum alveolar concentration (MAC) of sevoflurane for maintaining bispectral index (BIS) below 50 (MAC(BIS50) ) in children. BACKGROUND: MAC(BIS50) of sevoflurane in adults was reported to be 0.97%, which has not been elucidated in children. METHODS/MATERIALS: Twenty children, American Society of Anesthesiologists physical status I or II, aged 1-8, were induced and anesthetized with sevoflurane in oxygen. After tracheal intubation, we started maintenance of anesthesia with endtidal sevoflurane concentrations of 2.6%. The endtidal sevoflurane concentration at which BIS was measured was predetermined by the up-down method (with 0.2% as a step size). After 10 min at predetermined endtidal sevoflurane concentrations, BIS was measured for 1 min. MAC(BIS50) was determined using Dixon's up-down method and probit test. RESULT: MAC(BIS50) of sevoflurane was 2.83% (95% confidence intervals: 2.70-3.14) in children. CONCLUSIONS: MAC(BIS50) of sevoflurane in children was calculated to be three times as high as in adults. This indicates that high endtidal sevoflurane concentration is required to suppress electroencephalogram activity in children.

A novel association of alveolar capillary dysplasia, atypical duodenal atresia, and subglottic stenosis.

Alveolar capillary dysplasia (ACD), which is a rare and lethal congenital pulmonary anomaly found in newborns, begins its onset or causes deterioration of the infant's condition some time after birth. Various congenital anomalies in combination with ACD have been reported, except for subglottic stenosis. Therefore, we aim to report a novel association in a case of ACD with the combination of atypical duodenal atresia and subglottic stenosis. The male infant was scheduled for duodeno-duodenostomy because a double-bubble sign was observed on a chest radiograph. He arrived at the operating theater without any symptoms. After induction of general anesthesia, although mask ventilation was performed without difficulties throughout the entire procedure, oxygen saturation values of the upper and lower extremities dissociated after several attempts of intubation. Surgery was canceled because of instability of the respiratory condition. Respiratory insufficiency worsened progressively, and the infant died at 5 days of age. An autopsy confirmed ACD and revealed cartilaginous subglottic stenosis, which had made intubation difficult. This report highlights the hazards of the onset and worsening of ACD, and the importance of thorough echocardiography before surgery when atypical duodenal atresia is suspected. Anesthesiologists should also be prepared for the difficulty of intubation.

[Airway management using i-gel in two patients for awake craniotomy].

The i-gel (Intersurgical Ltd., Wokingham, Berkshire, UK) is a new single-use noninflatable supraglottic airway device. It is composed of a soft, gel-like, transparent, thermoplastic elastomer, which provides a perilaryngeal seal without cuff inflation. In this case report, we describe the airway management using i-gel in two patients scheduled for awake craniotomy. One patient underwent the implantation of brain stimulator electrodes and the other patient underwent the removal of a glioma near Broca's area. After anesthesia was induced with propofol and remifentanil, airway was secured using i-gel. Anesthesia was maintained using oxygen, air and propofol, supplemented with an infusion of remifentanil. Anesthesia was discontinued after completion of craniotomy. The i-gel was removed when patients opened their eyes upon calling their names out. The i-gel was reinserted before the closure of the dura without difficulties despite the fact that necks were rotated about 30 degrees rightward, and remained in place until the end of surgery. All procedures finished uneventfully and without adverse events. We conclude that i-gel is effective in asleep-awake-asleep technique because of its easiness in reinsertion under condition of rotated neck.

Preoperative droperidol improved postoperative pain relief in patients undergoing rotator-cuff repair during general anesthesia using intravenous morphine.

STUDY OBJECTIVE: To demonstrate the effect of preoperative and intraoperative, small-dose intravenous (IV) droperidol on postoperative pain relief in orthopedic patients given general anesthesia with morphine. DESIGN: Randomized, double-blind, prospective study. SETTING: University-affiliated hospital. PATIENTS: 84 ASA physical status I and II patients undergoing shoulder rotator-cuff repair with general anesthesia. INTERVENTIONS: Patients were randomly assigned to one of three groups: Group P (n = 27) wee given droperidol 10 microg/kg IV before skin incision; Group A (n = 30) received droperidol 10 microg/kg IV after skin incision; and Group C (n = 27) served as controls. General anesthesia consisted of sevoflurane and nitrous oxide in oxygen and IV morphine 0.2 mg/kg, which was given before skin incision. MEASUREMENTS: The degree of postoperative pain as assessed by postoperative pain scores and the number of supplemental analgesics given, and the frequency of postoperative nausea and vomiting, nightmares, and respiratory depression were compared among the three groups. A p-value < 0.05 was considered statistically significant. MAIN RESULTS: The postoperative pain score distribution was significantly greater in smaller values in Groups P and A than in Group C (p < 0.01). The number of supplemental analgesics given in the first 18 hours postoperatively was significantly smaller in Group P than in Groups A or C (p < 0.05). CONCLUSIONS: Preoperative IV droperidol resulted in improved postoperative pain relief inpatients undergoing shoulder rotator cuff surgery with general anesthesia using IV morphine.

The effect of propofol infusion on minimum alveolar concentration of sevoflurane for smooth tracheal intubation.

PURPOSE: This study was conducted to determine the effect of propofol infusion on the minimum alveolar concentration necessary for smooth tracheal intubation (MACEI) of sevoflurane. METHODS: Sixty-nine patients, American Society of Anesthesiologists (ASA) status I, aged 30-49 years, were randomly assigned to one of three groups according to the agents used for tracheal intubation (n = 23 for each group): the SP group, in whom the intubation was attempted under sevoflurane plus propofol infusion; the S group, tracheal intubation under sevoflurane alone; and the P group, tracheal intubation under propofol infusion alone. Anesthesia was induced with propofol 2.5 mg.kg(-1) i.v. bolus. Prior to the tracheal intubation attempt, propofol infusion, 10 mg.kg(-1).h(-1), was given for 15 min in the SP and P groups, and sevoflurane equilibration was established in the SP and S groups. All tracheal intubation attempts were made 15 min after anesthetic induction. The end-tidal sevoflurane concentration at which tracheal intubation was attempted was predetermined by the up-and-down method (with 0.5% as a step size). MACEI was determined using a logistic regression test. RESULTS: The MACEI of sevoflurane was 1.73% in the SP group, and 2.99% in the S group. Laryngoscopy was not possible in the P group patients. CONCLUSION: Propofol infusion reduced sevoflurane MACEI. This finding suggests that propofol would be an excellent adjuvant to use with sevoflurane for tracheal intubation.

Hemodynamic effects of oral clonidine premedication in lumbar epidural anesthesia.

Clonidine, an α2-adrenergic agonist, has a potent sympatholytic effect and augments the pressor effect of ephedrine during general anesthesia. We evaluated whether oral clonidine premedication would alter the hemodynamic changes and enhance the pressor response to intravenous ephedrine during epidural anesthesia in 35 adult patients. They were randomly administered either premedication with clonidine approximately 5 µg·kg-1 po (n=17) or no clonidine medication (n=18). After establishment of epidural anesthesia, the hemodynamic response to ephedrine iv was measured in the awake state at 1-min intervals for 10 min. Then, the same hemodynamic measurement was repeated in the asleep state induced with midazolam iv. There were no differences in blood pressure (BP) and heart rate values between groups during the onset of epidural anesthesia, except that BP before epidural anesthesia was lower in the clonidine group than the control group (P<0.05). The magnitude and duration of pressor responses to ephedrine were comparable between groups in awake and asleep states. In conclusion oral clonidine premedication 5 µg·kg-1 alters neither the hemodynamic changes nor the pressor response to intravenous ephedrine during epidural anesthesia.