Effects of Bupivacaine and Magnesium on Serotonin-induced Vasocontraction in an Isolated Human Umbilical Artery / 대한마취과학회지

BACKGROUND: Serotonin is found in the blood of the umbilical cord at birth in concentrations sufficiently high to affect vascular tone. Serotonin has been suggested to be involved in the pathogenesis of preeclampsia. Magnesium sulfate (MgSO4) is used to treat convulsions and hypertension in patients with preeclamptic toxemia. Bupivacaine is used in the epidural anesthesia for a cesarean section. The effects of magnesium and bupivacaine on serotonin-induced vasocontraction in a human umbilical artery was investigated. METHODS: Experiments were performed on 52 human umbilical arteries. The rings were suspended in an organ bath to record isometric mechanical activity. The concentration-contraction responses to bupivacaine, magnesium and serotonin were measured respectively. Vessels were pretreated with bupivacaine (10(-5) M) or magnesium (2 mM or 6 mM), and then serotonin (10(-9) M - 10(-6) M) was added cumulatively. Data analysis was assessed by an unpaired t test, one-way ANOVA and a Kruskal-Wallis test. RESULTS: Bupivacaine induced a contraction of umbilical arterial rings, and showed a maximal contraction (51.8 +/- 6.1%) at a concentration of 43nM. Magnesium induced relaxation of the umbilical artery in a concentration dependent manner. Pretreatment with bupivacaine (10(-5) M) potentiated significantly the concentration response to serotonin (P < 0.05). Pretreatment with MgSO4 (2 mM or 6 mM) significantly suppressed the contractile response to serotonin (P < 0.05). CONCLUSIONS: Bupivacaine, magnesium and serotonin are vasoactive on human umbilical arteries. Magnesium exerts a strong relaxant effect on serotonin induced vasocontraction in the human umbilical artery. Potentiation of serotonin induced vasoconstriction by bupivacaine may play a significant role in the reduction of umbilicoplacental blood flow.

A Comparative Study on Epidural Fentanyl, Bupivacaine, Lidocaine, and Intravenous Fentanyl in Patients Undergoing Gastrectomy under General Anesthesia / 대한마취과학회지

Backgronud : Postoperative pain control became anesthesiologist's familiar yield, so many anesthesiologists are very interested in opioid and local anesthetic's characterestics and there cardiovascular effects. It's important which anesthetic has the best pain killing and the least cardiovascular effect. We used epidural opioid and local anesthetics and intravenous opioid to investigate their pain killing and cardiovascular effects. METHODS: We studied 50 patients undergoing gastrectomy. An epidural catheter was placed via the T8-9 or L1-2 interspace. Epidural fentanyl group (Ep-F) received fentanyl 2 microgram/kg in 10ml saline, epidural bupivacaine group (Ep-B), 10 ml 0.25% bupivacaine, and epidural lidocaine group (Ep-L), 10 ml 1.5% lidocaine, epidurally; intravenous fentanyl group (IV-F) received fentanyl, 2 microgram/kg. 50% of the original dose was repeated every hour until the operation ended. Control group was given nothing before general anesthesia. Cardiovascular data was compared between those before and those at 1hour after skin incision. The time interval between end of the operation and the time of first analgesic requirement and the total number of intramuscular analgesic requirements during the first 48hours postoperatively were compared. RESULTS: Urinary output during surgery was significantly larger in group Ep-F. Group Ep-L developed more frequent episodes of hypotension. Group Ep-F, group IV-F and control group required higher enflurane concentrations. CONCLUSIONS: Group Ep-F was accompanied less hypotension and postoperative analgesic requirements were reduced.

A Clinical Study on Fatal Cases within 30 Days Following Surgery / 대한마취과학회지

BACKGROUND: A retrospective study was performed to evaluate postoperative mortality within 30 days following surgery. METHODS: The records of 31,806 patients who received operation under general anesthesia were reviewed. RESULTS: 1) Postoperative deaths were 184 cases, the ratio of which was comprising 0.57% of all surgical operative cases. 2) The highest ratio of the mortality in age group was 51~60 years group which was 24.5%, and in physical status it was ASA class III which was 36.4%. The highest ratio to the mortality rate in postoperative days was 8~30 days which was 45.1%. 3) The most common causes of death was low cardiac output due to heart failure on operating theater, and hypovolemic shock within postoperative 2 days, and intracranial problem within postoperative 7 days, and pulmonary complication within postoperative 30 days. CONCLUSION: We conclude that fatality rate could be decreased by intensive and multidisciplinary care for postoperaive complications as respiratory and renal failure.