Comparison of Clinical Effect of Low Dose Bupivacaine Added with Fentanyl and Conventional Dose Bupivacaine in Spinal Anesthesia for a Transurethral Resection of the Prostate / 대한마취과학회지

BACKGROUND: The combination of local anesthetics and opioids in the spinal anesthesia has a synergic analgesic effect. Therefore, we compared intraoperative conditions and clinical effects of low dose (5 mg) bupivacaine added with fentanyl versus a conventional dose(10 mg) of bupivacaine in spinal anesthesia for a transurethral resection of the prostate (TURP). METHODS: Forty five ASA class 1 and 2 patients scheduled for a TURP were randomly divided into three groups. Group B (n = 15) received bupivacaine 10 mg, group BF (n = 15) received bupivacaine 5 mg added with fentanyl 20microgram, and group BFE received bupivacaine 5 mg added with fentanyl 20microgram and 0.2 mg epinephrine. Blood pressure and heart rate were recorded every 5 minutes before and after spinal anesthesia. Sensory blockade was measured by a pin-prick test and motor blockade was evaluated by the Bromage motor scale. Side effects including pruritus, nausea, vomiting, respiratory depression, and intraoperative pain were observed. RESULTS: The duration of sensory and motor blockade in group BF was significantly shorter than in group B and group BFE (P<0.05). Without statistical significance, hypotension (6.7%) and bradycardia (13.3%) were observed in group B and pruritus (26.7%) and nausea (13.3%) occurred in all patients who received fentanyl. CONCLUSIONS: The addition of fentanyl 20microgram to low dose bupivacaine 5 mg resulted in short lasting motor and sensory block, compared with conventional dose bupivacaine 10 mg. Therefore, we concluded that the clinical application of this method could provide adequate analgesia with early discharge and no serious side effects for TURP patients.

Effects of Intravenous Anesthetics on EEG Spectral Analysis during Cesarean Section / 대한마취과학회지

BACKGROUND: Anesthesia induces the spectral changes in EEG. Attempts to relate these spectral changes to adequacy of anesthesia have been hindered due to the complex waveforms of EEG. The objective of this investigation is to monitor the awareness of patients during cesarean section by means of EEG spectral analysis. METHODS: 20 patients for cesarean section aged from 24 to 39 and ASA class I or II, were maintained with O2(50%)-N2O(50%)-enflurane(0.8%). And they were administered with midazolam(0.07 mg/kg) in group I(n=6), fentanyl(1 microgram/kg) in group II(n=7), and fentanyl(2 microgram/kg) in group III(n=7) after birth. The density of each spectral band in EEG (delta 1-3.25 Hz, theta 3.5-7.75 Hz, alpha 8-12.15 Hz and beta 13-31.75Hz) was analyzed to derive total density, delta ratio and median power frequency. RESULTS: The spectral data demonstrated that the alpha rhythm was dominant in pre-induction period and beta rhythm was abundant both in the immediate post-induction period and after birth for all three groups. Delta ratio and median power frequency decreased after injection of midazolam and fentanyl in all three groups. None of patients could recall the memory about experience during cesarean section. CONCLUSIONS: These findings indicate that EEG spectral analysis is potentially useful to determine the changes of cerebroelectrical activity but difficult to monitor the awareness of patients during cesarean section.

Effects of Volatile Anesthetics on Aortic Contractile Responses in Endotoxemic Rats / 대한마취과학회지

BACKGROUND: Endotoxins play important roles in the pathophysiologic alterations associated with sepsis so we examined the effects of volatile anesthetics on vascular smooth muscle contractile function in LPS-treated rat aorta. METHODS: Fifty male Sprague-Dawley rats(250~300 gm) were made septic by intraperitoneal injection of lipopolysaccharide(1.5 mg/kg). Cumulative doses of phenylephrine and norepinephrine(10 -8~10 -5M) were added to construct a contraction response curve. Two percent of volatile anesthetics, IBMX (3-isobutyl-1-methylxanthine, phosphodiesterase inhibitor) or L-NAME(Ng-nitro-L-arginine-methylester, Nitric oxide synthase inhibitor) was added and those contractile responses were observed respectively. We also measured nitric oxide synthase (NOS) activity of liver, lung and adrenal gland after 18 hours in the LPS-treated rats. Individual values between the control rats and LPS-treated rats were compared by unpaired t-test. A p-value less than 0.05 was considered statistically significant. RESULTS: Contractile response of 2% halothane to norepinephrine was significantly decreased both in the control rats and LPS-treated rats. The NOS inhibitor enhanced the contractile responses to phenylephrine and norephinephrine in the vessels from LPS-treated rats more significantly than those of control rats. CONCLUSIONS: These results suggest that LPS-treatment impairs vasopressor-induced contractility and doesn't alter the contractile responses during administration of volatile anesthetics.