The Effects of Insulin in Treating Bupivacaine-Induced Cardiac Depression / 대한마취과학회지

Backgroud: Bupivacaine blocks the sodium channels enhanced by hypokalemia. Bupivacaine also inhibits the transient outward K+ current (Ito). Insulin, in contrast, enhances Ito and induces hypokalemia. The current study was performed to confirm the efficacy of insulin for the treatment of bupivacaine- induced cardiac depression in dogs. METHODS: After dogs were anesthetized with pentobarbital, 0.5% bupivacaine was administered at a rate of 0.5 mg/kg/min until S O2 decreased to 60% or less, which was defined as the point of cardiac depression in this study. The insulin group (n = 9, 16.9 +/- 3.1 kg) received 2 ml/kg of a mixed solution of regular insulin 30 units and 5% D/W 50 ml, followed by a glucose infusion (50 ml 5% dextrose in water) over 15 min. The control group (n = 9, 15.8 +/- 3.4 kg) received 2 ml/kg of 5% D/W 50 ml, followed by a normal saline infusion over 15 min. Mean arterial pressure (MAP), heart rate (HR), pulmonary artery pressure (PAP), central venous pressure (CVP), pulmonary capillary wedge pressure (PCWP), cardiac output (CO), SO2, blood gas analysis, serum electrolytes, ECG and the local anesthetic concentraton of the blood were taken. RESULTS: Changes in hemodynamic variables and ECG of the insulin group normalized more rapidly than in the control group. There were no statistical differences in serum Na and Ca2 concentratons between the two groups. The serum K concentration of the insulin group was lower than that of the control group after 5 min of resuscitation. The changes in plasma bupivacaine concentration over time were not significantly different between groups. CONCLUSIONS: Insulin is effective in reversing bupivacaine-induced cardiac depression. This study suggests insulin can be considered an immediate treatment for cardiac depression by bupivacaine.

Comparison of the Cervical Spine Motion during Endotracheal Intubation with Lightwands and Macintosh Laryngoscopes / 대한마취과학회지

BACKGROUND: Endotracheal intubation with direct laryngoscope requires movement of the head, neck, and cervical spine. Spine movement may be limited for anatomical reasons or because of cervical spine injury. The lightwand requires less neck flexion and head extension than the conventional laryngoscope. The purpose of this study was to compare the extension of cervical spine obtained with lightwand and Macintosh laryngoscope. METHODS: Twenty patients requiring general anesthesia with endotracheal intubation were studied. Patients were placed on the operating table and anesthesia was induced. Intubation were performed on two occasions: with lightwands and Macintosh #3 laryngoscopes. Cricoid pressure was not applied. To determine cervical spine extension, five radiographs were taken in each patient (before induction, during mask ventilation, during intubation with lightwand, during laryngoscopy with the Macintosh blade: in the best glottic view or during intubation). RESULTS: Of 20 cases, we excluded 2 cases due to the technical error. Significant reduction of radiographic cervical spine extension were found in the lightwand compared to Macintosh blade at all cervical level. Mean atlantooccipital extension angles were 6.2o and 11.7o for the lightwand and Macintosh, respectively. There were no significant differences between mask ventilation and intubation with lightwand. CONCLUSIONS: Lightwand may be better than the conventional intubation in patients whose cervical spine movement is limited or undesirable, especially in the patients in whom awake intubation is not available.

An Experience in Anesthesia for Ambulatory Surgery / 대한마취과학회지

BACKGROUND: Ambulatory surgery has the advantages of reduced demand for postoperative medications, faster recuperation, less disruption to personal life and reduced hospital costs. At present, 60-70% of surgery in North America is performed on an ambulatory basis. DSC (day-surgery center) was opened on March 1995 in our hospital. We want to introduce an experience in anesthesia for ambulatory surgery. METHODS: Ambulatory surgeries were reviewed from March 1995 to July 1996. Total ambulatory surgeries were 5,593 cases. The medical records of 1,816 patients who were anethetized by anesthesiologists for ambulatory surgery were an alyzed retrospectively (3,777 patients who were operated under local anesthesia were excluded). RESULTS: The rate of utility was 14.1% on March 1995 and 27.7% on January 1996. The mean rate of utility was 22.2% per month in DSC. The overall mean rate of delayed discharge for the period was 2.9% and the overall mean rate of admission for the period was 1.9%. The principal reasons for the both were requestion by surgeons without surgery and anesthesia-related complications. CONCLUSIONS: The increase of demands of patients for ambulatory surgeries, new technological developements for surgery and anesthesia and increased experiences of surgeons will stimulate the utility of day surgery center.

Effects of Clonidine on Blood pressure and Heart rate, and Anesthetic Requirement During Laparoscopic Cholecystectomy / 대한마취과학회지

BACKGROUND: Laparoscopic cholecystectomy has become popular in the recent year. However, CO2 insufflation and patient's position changes during laparoscopic surgery can create severe hemodynamic changes, and increase anesthetic requirement. The major aim of this study is to assess the effect of oral clonidine on the cardiovascular lability during the operative and post-operative periods and enflurane requirement during operative period. METHODS: 43 patients(ASA I or II) undergoing elective laparoscopic cholecystectomy were selected for this study. The patients were randomly allocated into 3 groups: group 1(n=14) received no clonidine, group 2(n=15) 0.2 mg of clonidine and group 3(n=14) 0.3 mg of clonidine. Blood pressure and heart rate were continuously monitored during both the operative and post-operative periods. The enflurane concentration was also continuously adjusted to maintain blood pressure and heart rate within the range of 20% changes of baseline values. RESULTS: Since enflurane concentration was controlled to maintain systolic blood pressure within 20% of baseline values, there was no statistically significant difference in vital signs in the three groups during anesthesia. However, vital signs including systolic and diastolic blood pressure during their time in PACU (post anesthesia care unit) between the control and the clonidine treated groups were significantly different. The results of the blood pressure for the groups were found as follows. group 1) 134.9 +/-22.3 mmHg and 77.1 +/-12.4 mmHg, group 2) 116.8 +/-11.1 mmHg and 68.9 +/-12.2 mmHg and group 3) 113+/- 9.2 mmHg and 65.9+/- 9.2 mmHg for systolic and diastolic blood pressure respectively. Also, both the clonidine 0.2 mg and 0.3 mg treated groups, showed significantly decreased anesthetic requirement compared with the control group (P<0.05). There were dose dependent changes between 0.2 mg and 0.3 mg clonidine pretreated groups. CONCLUSIONS: Preoperative clonidine administration was effective in decreasing anesthetic supplement during laparoscopic cholecystectomy, and lessening the severity of hemodynamic changes during PACU.