Comparison of Effects of Fentanyl, Alfentanil and Remifentanil on the Cardiovasuclar Response to Endotracheal Intubation during the Induction of General Anesthesia / 대한마취과학회지

BACKGROUND: Opioids are the most widely used drugs to minimize the increase of blood pressure and heart rate in endotracheal intubation during the induction of anesthesia. The purpose of this study was to compare the effects of fentanyl, alfentanil, and remifentanil on the cardiovascular response to laryngoscopic endotracheal intubation. METHODS: Eighty ASA I-II patients were randomly allocated to four groups. The patients received 10 ml intravenous saline (control group), 3microgram/kg fentanyl (fentanyl group), 10microgram/kg alfentanil (alfentanil group) or 0.5microgram/kg remifentanil followed by an infusion of 0.1microgram/kg/min remifentanil (remifentanil group). Anesthesia was induced with propofol and rocuronium and maintained with 2 vol% sevoflurane and 50% nitrous oxide in oxygen. The noninvasive blood pressure and heart rate were recorded before induction (baseline), after induction, before intubation, and at 1 min intervals until 5 min after endotracheal intubation. RESULTS: Arterial pressure and heart rate after endotracheal intubation were lower in the fentanyl, alfentanil, and remifentanil groups than in the control group (P < 0.05). There were no significant differences for arterial pressure or heart rate in the fentanyl, alfentanil, and remifentanil groups at any time. There were no significant differences for the incidence of hypotension and bradycardia among the four groups. CONCLUSIONS: Administration of 3microgram/kg fentanyl, 10microgram/kg alfentanil and 0.5microgram/kg remifentanil followed by an infusion of 0.1microgram/kg /min remifentanil have a similar effect in the suppression of the cardiovascular response to laryngoscopic endotracheal intubation during the induction of general anesthesia.

The Effects of Esmolol on BIS, Patient Movement, and Hemodynamic Changes during General Anesthesia with Propofol / 대한마취과학회지

BACKGROUND: Lidocaine, alpha, beta-adrenergic blocker, angiotensin converting enzyme inhibitor, and various other analgesics have been used for blocking awakening, movements, and hemodynamic instability during general anesthesia. The purpose of this study was to evaluate the ability of esmolol to attenuate the cardiovascular, motor, and central nervous system responses to nociceptive stimulation, such as intubation, during general anesthesia. METHODS: Forty randomly selected patients participated in this study either as a control (n = 20) or as a study (n = 20) group, respectively. As soon as patients lost consciousness, at a propofol effect-site concentration of 4 microgram /ml, a touniquet was applied to one arm and inflated to 150 mmHg higher than the systolic pressure, and then vecuronium (1 mg/kg) was injected. Simultaneously esmolol (1 mg/kg + 250 microgram /kg/min) or normal saline were injected in the study and control groups respectively. Four minutes after starting esmolol, orotracheal intubation was administered. We monitered the BP, HR, BIS and gross movement during the study. RESULTS: Statistically significant differences were observed in mean BP, HR, and BIS between the two groups during esmolol injection. CONCLUSIONS: Esmolol can reduce anesthetic requirements during general anesthesia with propofol.

Effects of Mivacurium in the Strips of Rat Thoracic Aortic Rings / 대한마취과학회지

BACKGROUND: The hypotensive effects of muscle relaxants has traditionally been associated with a ganglion block and histamine release. However, it was exhibited that the ability of certain analogues of the steroidal muscle relaxant directly caused relaxation of isolated vascular smooth muscles. The ability of mivacurium to elicit a direct relaxant effect on vascular smooth muscle has been studied using isolated rat thoracic aortic rings contracted with phenylephrine (PE). METHODS: Each ring of the thoracic aorta was suspended on wire supports in a 20 ml tissue bath under 2 gm of resting tension. All tissues were bathed in a Tris Tyrode solution at 37oC and 100% oxygen was supplied. RESULTS: Mivacurium 3 X 10 5 M and 10 3 M inhibited PE induced contractions of the aortic rings significantly (P < 0.05) and shifted the cumulative concentration-effect curves of PE to the right. The maximum contractile response from 81.9% to 55.0% (with PE 10 6 M) was the same as that seen with mivacurium 10 3 M pretreatment. Relaxation of aortic ring with mivacurium 10 3 M was not reversed with L-NAME pretreatment. Methylene blue reversed the relaxation of the aortic rings with mivacurium 10 3 M and shifted the cumulative concentration-effect curve of PE to the left. Indomethacine enhanced the relaxation of the aortic rings with mivacurium 10 3 M and shifted this curve to the right. Mivacurium 10 3 M inhibited the influx of extracellular Ca2+. CONCLUSIONS: The results suggest that the relaxation effects of mivacurium is related with the endothelium and at least, in part, cyclooxygenase inhibition and guanylate cyclase activation are related with this relaxation effect. Also, mivacurium inhibited extracelluar calcium influx.

Efficacy and Safety of Short-term Administration of Rifaximin in the Treatment of Hepatic Encephalopathy / 대한간학회지

BACKGROUND/AIMS: A prospective, randomized study was performed to evaluate the efficacy and safety of the short-term administration of rifaximin in the treatment of hepatic encephalopathy. METHODS: Of the 64 patients diagnosed as having decompensated liver cirrhosis with hepatic encephalopathy, 39 patients were randomized to receive rifaximin and 25 patients to receive lactulose for seven days. Before and after the treatment we assessed changes in the level of serum ammonia, flapping tremor, patient's mental status, number connection test (NCT), and hepatic encephalopathy indices. RESULTS: In rifaximin-treated group, the mean grade of serum ammonia (1.8->0.9), mental status (1.3->0.3), NCT (3.0->2.0), and flapping tremor (1.7->0.4) were improved after treatment. In the lactulose-treated group, the mean grade of serum ammonia (1.9->1.0), mental status (1.5->0.5), NCT (3.3->2.1), and flapping tremor (1.4->0.3) were improved after treatment. Side effects of abdominal pain (rifaximin group) and excessive diarrhea (lactulose group) were noted in 2 cases. The efficacy of treatment was not significantly different between rifaximin and lactulose-treated groups (84.3% vs. 95.3%). CONCLUSION: Rifaximin was as efficient and safe in the treatment of hepatic encephalopathy as lactulose in terms of efficacy. Rifaximin may be useful drug for the short-term treatment of hepatic encephalopathy.