Hyo Seok Kang

The influence of age and gender on remifentanil EC50 for preventing rocuronium induced withdrawal movements

Background Rocuronium-induced withdrawal movements can be harmful to patients during the induction period. Remifentanil has been reported to reduce these movements effectively. In this study, we determined the EC50 of remifentanil for the prevention of rocuronium induced withdrawal movements in male, female, old and child group. Methods We included patients scheduled for general anesthesia and assigned them into 4 groups depending on their age and gender: male group (20-60 yr), female group (20-60 yr), old group (>65 yr) and child group (6-12 yr). Remifentanil was administered by target controlled infusion. Propofol 2 mg/kg was then administered after equilibration between the effect and plasma concentration of remifentanil was reached. After loss of consciousness, rocuronium 0.6 mg/kg was administered. Patients response to the rocuronium was graded using a 4 point scale in a blinded manner. The EC50 of remifentanil for preventing rocuronium induced withdrawal movements was determined using Dixons up-and -down method. Results The EC50 of remifentanil for preventing rocuronium induced withdrawal movements was 1.8 ± 0.5 ng/ml [95% confidence interval 1.3-2.2] in the male group, 2.3 ± 1.0 ng/ml [1.3-3.2] in the female group, 0.5 ± 0.4 ng/ml [0.2-0.8] in the old group and 2.8 ± 0.8 ng/ml [2.1-3.5] in the child group. Conclusions The EC50 of remifentanil for preventing rocuronium induced withdrawal movements was lowest in the elderly and higher in children than male adult patients. No difference in the EC50 of remifentanil was seen between male and female adult patients.

The optimal preemptive dose of gabapentin following gynecologic surgery

BACKGROUND Gabapentin decreases acute nociceptive pain in animal and human studies when given before surgical incision. Various doses of gabapentin have been used (300-1,200 mg) to measure this preemptive effect. Here, we evaluated the optimal dose of gabapentin for reducing fentanyl consumption and the adverse effects of gabapentin following gynecologic surgery. METHODS We recruited 100 patients who underwent laparotomy for gynecologic surgery. Patients were randomly divided into 4 groups and received a placebo (control), gabapentin 300 mg (G 300), gabapentin 600 mg (G 600), or gabapentin 1,200 mg (G 1200) 2 h before surgery. Postoperatively, patients received fentanyl via an intravenous patient controlled analgesia device. The cumulative fentanyl doses were recorded 2, 6, 12, 24 h, and 48 h postoperatively, and the sedation scale was recorded in the post anesthetic care unit (PACU). RESULTS The postoperative fentanyl requirement was lower with gabapentin treatment, but there was no significant differences for the different doses. PACU sedation scores were not different in any group. CONCLUSIONS Gabapentin has a preemptive effect in gynecologic surgery, but there were no additional fentanyl-sparing benefits at doses above 300 mg. Thus, 300 mg is an optimal dose for decreasing fentanyl consumption following gynecologic surgery.

Airway management in a patient with Treacher Collins syndrome - A case report -

Treacher Collins Syndrome (TCS) is an autosomal dominant genetic disorder which is resulted from the mutation that affect the Treacher Collins-Franceschetti syndrome 1 (TCOF1) gene on chromosome 5. The features of patients affected by this syndrome are characterized by depression of the malar bones, an antimongoloid slant of the palpebral fissures, coloboma of the lower lids, mandibular hypoplasia with retrognathia and deformities of the ear structures. The airway obstruction is frequently caused by mandibular hypoplasia. This may necessitate the placement of a tracheostomy for airway patency after the birth. We experienced a tracheostomy for an infant with respiratory difficulty associated airway obstruction.

Comparison of alfentanil and remifentanil for the use of patient controlled sedation under local anesthesia during ear, nose and throat surgery

BACKGROUND This study was conducted to compare the effects of alfentanil and remifentanil on patient controlled sedation (PCS). METHODS 60 patients scheduled for ear, nose and throat surgery under local anesthesia were randomly allocated to Group P (n = 20, propofol 10 mg/ml), Group A (n = 20, propofol 10 mg/ml with alfentanil 500 microg/ml) and Group R (n = 20, propofol 10 mg/ml with remifentanil 10 microg/ml). Without a basal rate, bolus was set to 2 ml with one minute of lockout time. RESULTS A total of 57 patients were included in this study. Group A was found to have a lower blood pressure and pulse rate than group R. Group R showed a lower PCS dose upto an OAA/S (Observers Assessment of Alertness/Sedation Scale) value of 4 and a higher OAA/S prior to surgery than group P. Group P was found to have a higher blood pressure and respiration rate than Group A. During PCS, patient anxiety was significantly decreased in all groups. In addition, there was no differences among groups in the level of pain during the perioperative period, delivery/attempt ratio, satisfaction of the patient and surgeon, and number of patients required to undergo the same PCS technique again. The frequency of side effects of PCS, which included pain on injection, transient hypertension, hypotension, desaturation and oversedation, were similar among groups. CONCLUSIONS Evaluation of patients who underwent ear, nose and throat surgery under local anesthesia using PCS with propofol alone or alfentanil or remifentanil revealed no differences in safety, effectiveness, complications or satisfaction of the patients and surgeons.