Chee-Mahn Shin

Comparison of dexmedetomidine and remifentanil for attenuation of hemodynamic responses to laryngoscopy and tracheal intubation

Background This study was designed to compare the effect of dexmedetomidine and remifentanil used in anesthetic induction on hemodynamic change after direct laryngoscopy and tracheal intubation. Methods A total of 90 ASA class 1 or 2 patients were randomly assigned to one of 3 groups to receive one of the following treatments in a double-blind manner: normal saline (Group C, n = 30), dexmedetomidine 1 µg/kg (Group D, n = 30), remifentanil 1 µg/kg (Group R, n= 30). Anesthesia was induced with propofol 2 mg/kg and rocuronium 0.6 mg/kg and maintained with 2 vol% sevoflurane and 50% nitrous oxide in oxygen. In group D, dexmedetomidine 1 µg/kg was infused for 10 min before tracheal intubation. Patients in group R was received 1 µg/kg of remifentanil 1 minute before tracheal intubation. The systolic blood pressure, diastolic blood pressure and heart rate were recorded from entrance to operation room to 5 min after tracheal intubation. Results The percent increase in systolic and diastolic blood pressure due to tracheal intubation in group D and R were significantly lower than that of group C (P < 0.05). The heart rate 1 min after tracheal intubation was lower in groups R and D than in the group C (P < 0.05). Conclusions In healthy normotensive patients, the use of dexmedetomidine during anesthetic induction suppressed a decrease in blood pressure due to anesthetic induction and blunted the hemodynamic responses to endotracheal intubation.

Analgesic effect of preoperative versus intraoperative dexamethasone after laparoscopic cholecystectomy with multimodal analgesia

Background Pain after laparoscopy is multifactorial and different treatments have been proposed to provide pain relief. Multimodal analgesia is now recommended to prevent and treat post-laparoscopy pain. Dexamethasone is effective in reducing postoperative pain. The timing of steroid administration seems to be important. We evaluated the analgesic efficacy of preoperative intravenous dexamethasone 1 hour before versus during laparoscopic cholecystectomy with multimodal analgesia. Methods One hundred twenty patients aged 20 to 65 years old were allocated randomly into one of three groups (n = 40, in each). The patients in the group N received normal saline 1 hour before induction and after the resection of gall bladder. The patients in the group S1 received dexamethasone 8 mg 1 hour before induction and normal saline after the resection of gall bladder. The patients in the group S2 received normal saline 1 hour before induction and dexamethasone 8 mg after the resection of gall bladder. Results VAS scores of group S1 and S2 were lower than that of group N during 48 hours after laparoscopic cholecystectomy. There were no significant differences of VAS scores between the group S1 and the group S2. The analgesic consumption of group S1 and S2 were significantly lower than that of group N. Conclusions A single dose of dexamethasone (8 mg) intravenously given 1 hour before induction or during operation was effective in reducing postoperative pain after laparoscopic cholecystectomy with multimodal analgesia. The analgesic efficacy of preoperative intravenous dexamethasone 1 hour before versus during surgery was not significantly different.

Prevention of pain during injection of microemulsion propofol: application of lidocaine mixture and the optimal dose of lidocaine

Background Similar to lipid emulsion propofol, microemulsion propofol also causes a high incidence of pain during intravenous injection. Various methods have been used to minimize the incidence and severity of pain on injection of lipid emulsion propofol. In this study, we investigated the effect of a lidocaine mixture on pain induced by microemulsion propofol injection, and sought to determine the optimal dose of lidocaine that could reduce pain on injecting a propofol-lidocaine mixture. Methods One hundred sixty (n = 160) patients of American Society of Anesthesiologists physical status class I or II were randomly allocated to four groups: Group A, control; Group B, 20 mg lidocaine; Group C, 30 mg lidocaine; Group D, 40 mg lidocaine. In each patient, pain on microemulsion propofol solution injection was graded as none, mild, moderate, or severe. Results The incidence of pain in groups A, B, C, and D was 97.5%, 80%, 65%, and 50%, respectively. Increasing the lidocaine dose significantly reduced pain (P < 0.05). One patient in Group D (2.5%) had moderate to severe pain, which was significantly lower than groups B (42.5%) and C (32.5%) (P < 0.05). Conclusions The lidocaine and propofol mixture is effective in alleviating pain associated with microemulsion propofol injection. Within this dose range and in this patients population, increasing lidocaine dosage significantly reduced pain during injection of microemulsion propofol.

Abrupt formation of a right atrium thrombus detected by transesophageal echocardiography during laparoscopic assisted vaginal hysterectomy and spontaneous resolution during thromboembolectomy -A case report-

Intraoperative formation and management of a thrombus in right atrium has been reported occasionally. Nevertheless, it is rare that a right atrial thrombus with unstable hemodynamic changes detected by transesophageal echocardiography is resolved spontaneously. We report upon the 44-year-old woman, who had a right atrial thrombus detected by transesophageal echocardiography during laparoscopic assisted vaginal hysterectomy and resolved during thromboembolectomy.

A patient with Churg-Strauss syndrome who underwent endoscopic sinus surgery under general anesthesia -A case report-

There are many cause of cholinesterase deficiency, including drugs, liver disease, chronic anemia, malignant states, cardiac failure, severe acute infection, surgical shock, severe burn, collagen disease and vasculitis syndromes. Vasculitis syndromes are relatively rare, and among them, Churg-Strauss syndrome (CSS) is even rarer. We report here on a case of a patient with CSS who underwent endoscopic sinus surgery under general anesthesia.

Effect of remifentanil on QT dispersion

BACKGROUND QT dispersion (QT(d)) is an indirect measure of the heterogeneity of ventricular repolarization and can be used as a risk factor for complex ventricular arrhythmias. We measured the effect of remifentanil on QT(d) and heart-rate corrected QT dispersion (QT(cd)). METHODS Sixty ASA class I and II patients, who were between 20 and 60 years old, and who were scheduled for general anesthesia, were studied. After the patient entered the operating room, a 12 lead EKG recording was taken and intravenous infusion of remifentanil was started. The infusion rate was 0.1 microg/kg/min in group 1 and 0.2 microgram/kg/min in group 2. Another EKG recording was taken 10 minutes after infusion had started. RESULTS In both groups, QT(d) following remifentanil infusion was not significantly different than control values (76.6 +/- 23.3 ms vs 81.8 +/- 34.9 ms, P = 0.459 in group 1; 70.7 ms +/- 29.7 ms vs 73.7 ms +/- 37.1 ms, P = 0.734 in group 2). Neither was QT(cd): (83.2 ms +/- 25.2 ms vs 89.6 ms +/- 36.2 ms, P = 0.371 in group 1; 81.0 ms +/- 35.2 ms vs 83.4 ms +/- 40.9 ms, P = 0.829 in group 2). CONCLUSIONS Remifentanil infusion at a rate less than 0.2 microg/kg/min does not change QT(d) or QT(cd).

Uncontrollable hyperthermia in acute cerebral injury - A Case report -

A 39 year old man arrived at the hospital with semi-comatose state as a result of spontaneous intracerebral hemorrhage (ICH), intraventricular hemorrhage (IVH) and subarachnoid hemorrhage (SAH). For emergency craniectomy and hematoma removal, general anesthesia with desflurane and vecuronium was planned. Before the induction of anesthesia, the body temperature and end-tidal carbon dioxide (ETCO2) levels were 38.3degrees C and 38 mmHg, respectively. The body temperature and ETCO2 increased during surgery. After 2 hours of anesthesia, the temperature had increased to 41degrees C, despite bladder irrigation and body cooling. After 3 hours of anesthesia, the temperature reached 43.5degrees C and cardiac arrest developed. Cardiopulmonary resuscitation was attempted, but the patient expired.

Predictable normocapnoea in controlled ventilation of infants with Jackson Rees or Bain system

We have devised a formula for ventilator settings which would provide normal minute ventilation without rebreathing during controlled ventilation using a Jackson Rees or Bain system. As V T = V S + V F − V L, where V T = delivered tidal volume, V S = set tidal volume, V F = the volume of fresh gas entering during the inspiratory phase and V L = the lost volume due to the compliance of the system, V S was derived: V S = V L + V T × [1 − b/(1 + a)] where a = expiratory‐to‐inspiratory ratio and b = the ratio of fresh gas flow to the minute ventilation. It was evaluated in 62 infants. Arterial partial pressure of carbon dioxide (mean (SD)) was 4.6 (0.5) kPa (35 (4) mmHg) with a range of 3.42–5.78 kPa (26–44 mmHg). The 90th percentile was 5.1 kPa (39 mmHg). It is concluded that predictable normocapnoea can be conveniently achieved in infants in controlled ventilation with Jackson Rees or Bain system if our formula is applied.