Soon Ho Nam

The effect of pneumoperitoneum in the steep Trendelenburg position on cerebral oxygenation.

Background: daVinci® robot‐assisted laparoscopic radical prostatectomy (RALP) requires pneumoperitoneum in the steep Trendelenburg position, which results in increased intracranial pressure and cerebral blood flow. The aim of this study was to evaluate the effect of pneumoperitoneum in a 30° Trendelenburg position on cerebral oxygenation using regional cerebral oxygen saturation (rSO2).

Comparison of Remifentanil and Fentanyl for Postoperative Pain Control after Abdominal Hysterectomy

Purpose In this randomized, double-blind study, we investigated the analgesic efficacy and side effects of continuous constant-dose infusions of remifentanil after total abdominal hysterectomy and compared it to fentanyl. Materials and Methods Fifty-six adult female patients scheduled for elective total abdominal hysterectomy were enrolled in this study. Patients were randomly assigned to two groups according to fentanyl (group F, n = 28) or remifentanil (group R, n = 28) for postoperative analgesia. Patients in group F were given fentanyl intravenously with an infusion rate of fentanyl 0.5 µg/kg/hr; group R was given remifentanil with an infusion rate of remifentanil 0.05 µg/kg/min for 2 days. Pain intensity at rest, occurrence of postoperative nausea and vomiting (PONV), dizziness, pruritus, and respiratory depression were assessed 1 hr after arrival at the post-anesthesia care unit, at 6; 12; 24; and 48 hr postoperation and 6 hr post-infusion of the study drug. Pain was evaluated by using visual analogue scale (VAS; 0 - 10). The time that patients first requested analgesics was recorded as well as additional analgesics and antiemetics. Results There were no significant differences in VAS, time to first postoperative analgesics, and additional analgesics between the 2 groups. The incidences and severities of PONV and opioid related side effects were not different between the groups; however, there were 3 episodes (10.7%) of serious respiratory depression in group R. Conclusion Continuous infusion technique of remifentanil did not reveal any benefits compared to fentanyl. Furthermore, it is not safe for postoperative analgesia in the general ward.

Low-dose remifentanil to modify hemodynamic responses to tracheal intubation: comparison in normotensive and untreated/treated hypertensive Korean patients.

Background Remifentanil has been shown to be effective at treating potentially adverse hemodynamic responses to tracheal intubation even at low doses (< 1 µg/kg/min), which needs to be evaluated in patients with diverse cardiovascular conditions. Methods A low-dose regimen of remifentanil (continuous infusion of 0.1 µg/kg/min, preceded by 0.5 µg/kg bolus) was given before induction with bolus propofol and rocuronium, and heart rate as well as systolic, diastolic, and mean arterial pressures were measured at 1 min intervals from before induction to 5 min after tracheal intubation in normotensive patients, untreated hypertensive patients, and patients with known hypertension. Results The low-dose regimen of remifentanil resulted in parallel hemodynamic responses in all three groups, and was effective at limiting hemodynamic responses to tracheal intubation without excessive cardiovascular depression. Hemodynamic responses in our study showed a similar pattern to that reported in previous investigations, except for elevations in heart rate and arterial pressures over the baseline values immediately after intubation. Conclusions We suggest that the low-dose regimen of remifentanil in our study could be routinely used to modify hemodynamic responses to tracheal intubation in patients with diverse hemodynamic characteristics. However, the development of supplementary regimens is still needed to control the brief, but exaggerated responses to tracheal intubation, especially in untreated hypertensive patients.

Ventricular arrhythmia in patients with prolonged QT interval during liver transplantation: two cases report

QT interval prolongation is associated with an increased risk of ventricular arrhythmia in various conditions. Cardiac electrophysiologic abnormalities including QT interval prolongation are well documented in patients with advanced liver cirrhosis. We report two cases of patients with QT interval prolongation on preoperative electrocardiography who exhibited repetitive ventricular arrhythmias with significant hemodynamic deterioration during liver transplantation. For the treatment and prevention of ventricular arrhythmias during the intraoperative period, we performed intravenous administration of lidocaine and isoproterenol, corrected imbalances of electrolytes including potassium and magnesium, and prepared a defibrillator. These cases emphasize that preoperative recognition of QT interval prolongation and adequate management to prevent fatal arrhythmias are important in patients undergoing liver transplantation.

Assessment of cerebral oxygen supply-demand balance by near-infrared spectroscopy during induction of anesthesia in patients undergoing coronary artery bypass graft surgery: comparison of midazolam with propofol

BACKGROUND Near-infrared spectroscopy (NIRS) continuously measures regional cerebral oxygen saturation (rSO2) noninvasively and has been shown to detect even small changes in cerebral oxygen supply-demand balance. Although widely used, only the effect of midazolam on cerebral blood flow has been studied in humans and evidence is lacking about its effect on cerebral metabolic rate. We therefore evaluated the effect of midazolam on cerebral oxygen supply-demand balance with NIRS. METHODS Sixty patients undergoing elective coronary artery bypass graft surgery were randomly allocated into either midazolam (n = 30) or propofol (n = 30) group. rSO2 was recorded before induction while patients were breathing room air as baseline, after pre-oxygenation with 100% oxygen, after administration of either midazolam or propofol, after completion of administration of sufentanil and after tracheal intubation. Hemodynamic variables including cardiac index and mixed venous oxygen saturation were recorded at the same time points. RESULTS rSO2 and hemodynamic variables were similar between the groups throughout the study period. After pre-oxygenation, rSO2 significantly increased compared to baseline in each group, and did not show any additional increase after administration of either midazolam or propofol and sufentanil in both groups. CONCLUSIONS Midazolam preserves cerebral blood flow-metabolism coupling to a similar degree to propofol as assessed by near infrared spectroscopy.