Relaxant Effects of Thiopental, Ketamine, and Propofol on Isolated Rat Tracheal smooth Muscle / 대한마취과학회지

BACKGROUND: Intravenous anesthetics may modify airway responsiveness. The author investigated the relaxant effect of thiopental, ketamine, and propofol on isolated rat tracheal smooth muscles. METHODS: The trachea of the rat was dissected and cut into 3-mm rings. The rings were mounted in a water-jacked organ bath filled with Krebs solution aerated with 95% O2 and 5% CO2 at 37degreesC. Thiopental, ketamine, and propofol were given randomly to each ring preconstricted with EC50 of acetylcholine from 10(-6) to 10(-3) M. The relaxation response was the tension during anesthetic equilibration, expressed as a percentage of the tension from EC50 of acetylcholine. RESULTS: Thiopental and propofol (10(-5) to 10(-3) M) relaxed acetylcholine-induced contractions in a dose dependent manner (P < 0.05). Ketamine in doses of 10(-5) and 10(-4) M constricted acetylcholine-induced contractions by 3.2% and 16.5% respectively (P < 0.05). But ketamine in a dose of 10(-3) relaxed acetylcholine-induced contractions by 76.4% (P < 0.05). The relaxation of tracheal smooth muscles was greatest in thiopental, and was least in ketamine (P < 0.05). CONCLUSIONS: All three intravenous anesthetics have an excellent relaxation of tracheal smooth muscles in rats, except in doses of 10(-5) and 10(-4) M of ketamine.

The Effects of Intravenous Thiopental Injection on Jugular Venous Oxygen Saturation (SjVO2) during Cerebral Aneurysm Surgery / 대한마취과학회지

BACKGROUND: Thiopental has a profound impact on the cardiovascular system. The effects of hemody namics after intravenous thiopental on the balance of cerebral metabolism with cerebral blood flow is unknown. The purpose of this study was to monitor hemodynamic change, cerebral arterial-jugular venous oxygen content difference (AVDO2) and jugular venous oxygen saturation (SjVO2) after a thiopental injection for brain protection during cerebral aneurysm surgery. METHODS: Twenty patients received a standard anesthetic consisting of isoflurane, vecuronium and fentanyl with a PaCO2 of 30 35 mmHg. Hemodynamics, arterial and jugular venous blood gases were measured at 3 time points:I; Just before thiopental injection; II; Electroencephalographic (EEG) burst suppression after a 4 5 mg/kg intravenous thiopental injection; and III; EEG recovery. RESULTS: Intravenous thiopental (4 5 mg/kg) induced an EEG burst suppression for 6.5 +/- 1.7 minutes. Hemodynamics and arterial blood gas analysis were not significantly different among the different time points, but mean arterial pressure (68.4 +/- 7.2 mmHg) and systemic vascular resistance (1027.0 +/- 300.9 dynes sec/cm5) in II were significantly (P < 0.05) decreased compared with I (84.3 +/- 9.6, 1169.1 +/- 304.5) and III (89.1 +/- 10.6, 1288.6 +/- 426.1). SjVO2 (71.6 +/- 11.8%) was significantly (p < 0.05) decreased within the normal value compared with I (75.1 +/- 5.6) and III (76.1 +/- 10.1), but AVDO2 was not significantly different among the 3 time points. There was no evidence of cerebral ischemia or infarction in computed tomographic (CT) findings of the 20 patients after surgery. CONCLUSIONS: Hemodynamics after 4 5 mg/kg intravenous thiopental do not modify the balance ofcerebral oxygen metabolism with cerebral blood flow in patients undergoing cerebral aneurysm surgery.

Coma State after Giant Cerebral Artery Aneurysm Clipping Surgery under Circulatory Arrest, Hypothermia and Barbiturate: A case report / 대한마취과학회지

Giant aneurysms and some basilar aneurysms can cause some problems due to their size and clot formation within them. Recently, profound hypothermia and barbiturate cerebral protection were used for successful surgical treatment of these complex intracranial vascular lesions. We experienced a female patient with a giant anterior aneurysm. After femoral arterial and venous cannulation, cardiopulmonary bypass was performed and the aneurysm was clipped under a state of deep hypothermic circulatory arrest. However, she developed postoperative brain swelling and coma and died due to respiratory failure in ICU.

Analysis of Intradermal Test for Anesthetic Drugs / 대한마취과학회지

BACKGROUND: Intradermal test is a useful diagnostic method for acute anaphylactoid or anaphylactic reactions induced by anesthetic drugs. We analyzed the responses of intradermal test for anesthetic drugs in patients who did not show anaphylactoid or anaphylactic reactions. METHODS: The authors performed intradermal test for anesthetic drugs (thiopental, midazolam, fentanyl, atracurium and vecuronium) in 224 adult patients one hour before induction of anesthesia. The responses were interpreted as measuring the size of wheal and flare. We also did history taking for past allergic history. RESULTS: There were no patient that showed positive reaction. The rate of false positive reaction for atracurium (12.5%) was significantly higher than other anesthetic drugs (p<0.05). And the rate of false positive reaction for atracurium in patients under the age of 40 (20%) was significantly higher than those above the age of 40 (3.8%) (p<0.05). But the difference of the rate of false positive reaction for atracurium between male (8%) and female (15.3%) was not significant statistically. The differences of the rates of false positive reaction for anesthetic drugs between past allergic history group and no past allergic history group were not statistically significant. CONCLUSIONS: In intradermal test for anesthetic drugs, the rate of false positive reaction for atracurium was significantly higher than thiopental, vecuronium, fentanyl and midazolam. Especially, it was significantly higher in patients under the age of 40. So in performing intradermal test to search for causative anesthetic drug, we have to consider the high rate of false positive reaction for atracurium.

Hydrothorax and Inadvertent Administration of Thiopental Sodium Following Malpositioned Internal Jugular Vein Catheter: A case report / 대한마취과학회지

A 53-year-old female admitted for multiple rib fracture, hemoptysis and dyspnea due to traffic accident. High resonance CT of the chest revealed bronchiectasis in left lower lobe. She presented for left lower lobectomy with the consent of her. A day before the operation, right internal jugular vein catheter was placed using anterior approach, and free blood flow was achieved. 2 hours after the procedure, she complained of mild chest pain and dyspnea but it was thought to reflect the rib fracture, and then 2 liters of fluid was administered through internal jugular vein catheter. Conducting anesthesia, thiopental sodium and succinylcholine chloride was administered through this route. But loss of consciousness of the patient didn't occur. The chest x-ray taken in OR showed hydrothorax on right pleural cavity.

Spectral Analysis of Heart Rate and Blood Pressure Variability during Hemorrhage in Thiopental-anesthetized Rats / 대한마취과학회지

BACKGROUND: This study was aimed to elucidate the effect of thiopental anesthesia on circulatory response to hemorrhage in rats by power spectral analysis of heart rate and blood pressure variability. METHODS: Sixteen male Sprague-Dawley rats weighing 350~475 g were divided into thiopental (50 mg/kg, ip)-anesthetized (T, n=10) and conscious (C, n=6) groups. Hemorrhage was induced with a withdrawal pump from the femoral artery at 3 ml/kg/min for 5 min. Arterial pressure was measured with a pressure transducer connected to the contralateral femoral artery for 5 min before, during and after hemorrhage. The blood pressure signal digitized at 500 Hz through a data acquisition system was analyzed with fast Fourier transform algorithm to yield power spectra of sytolic (SP) and diastolic (DP) blood pressure and instantaneous heart rate (HR). Powers of very low frequency (VLF, 0.02~0.26 Hz), low frequency (LF, 0.26~0.75 Hz) and high frequency (HF, 0.75~5.00 Hz) band were expressed as percent of total power. RESULTS: Before Hemorrhage blood pressure was lower in T (113 6/83 6 mmHg) than in C (157 4/101 2) rats, but was not changed by hemorrhage in both groups. Before Hemorrhage HR was lower in T (331 22 beats/min) than in C (378 27) rats. HR was significantly increased to 412 26 beats/min in C, but was not changed in T during hemorrhage. Total powers of Before Hemorrhage blood pressure and HR variability were lower in T than in C. During hemorrhage, total power of blood pressure variability tended to increase in both groups, and that of DP was significantly increased during hemorrhage in T. Total power of HR was significantly increased in C, but was not changed in T. T rats showed lower LF and higher HF power of blood pressure, and lower VLF and LF and higher HF power of HR than C rats. During hemorrhage, both groups showed no significant change in spectral distribution of HR power, except for a significant increase in LF of HR after hemorrhage in C. Spectral distribution of blood pressure power was not changed by hemorrhage in C. In T rats, VLF of DP was significantly increased and HF of DP was decreased during hemorrhage. CONCLUSIONS: It suggests that autonomic activity, especially cardiac sympathetic activity is increased in response to hemorrhage in C. Thiopental anesthesia depresses overall autonomic activity, especially sympathetic activity, and vasomotor tone. Hemorrhage under thiopental anesthesia induces depression of baroreceptor reflex activity, while increased levels of vasoconstrictor hormones help to maintain the blood pressure.

Anesthetic Management for Carotid Endarterectomy: case report / 대한마취과학회지

We have experienced an anesthetic management of 56-year-old male patient with carotid stenosis. Carotid endarterectomy was performed with processed electroencephalography (compressed spectral array, CSA) monitoring. Carotid endarterectomy has significant risk of perioperative stroke and myocardial infarction. For brain protection during carotid cross clamp, body temperature of patient was maintained at 33.5oC and thiopental was infused continuously to induce burst suppression. To maintain blood pressure during cross clamp, dopamine was infused continuously and phenylephrine was injected intermittently. CSA was performed to monitor thiopental-induced burst suppression and ischemic brain insult. After releasing carotid cross clamp, body temperature was raised to 35oC.

Effects of Hydroxocobalamin on Thiopental-Induced Contractile Responses of Septic Rat Thoracic Aorta / 대한마취과학회지

BACKGROUND: Endotoxins play important roles in the pathophysiologic alterations associated with sepsis so the authors examined the effects of hydroxocobalamin, NW-nitro-L-arginine-metyl ester (L-NAME) and aminoguanidine on thiopental-induced contractile responses of lipopolysaccharide (LPS)-treated and control rat aortic rings. METHODS: Aortic ring preparation was obtained from LPS-treated (1.5mg/kg, i.p. for 18h) rats. Cumulative doses of thiopental (10-4~3x10- 3M) were added to construct contraction response curves. Hydroxocobalamin (10-5M), L-NAME (10-6M) or aminoguanidine (10-6M) were added as NO scavenger or as NOS inhibitors. Contraction curves by cumulative doses of thiopental (10-4~3x10-3M) were remeasured after treatment of NO scavenger or NOS inhibitors. Statistical significances (p<00.05) were analyzed according to data characteristics by Student's t-test, paired t-test or ANOVA. RESULTS: The vascular responses of cumulative thiopental (10-4~3x10 3M) administration were dose- dependent contraction and LPS-treated rat was less contracted (p<00.05). There was significant increment on vascular contraction induced by thiopental after hydroxocobalamin pretreatment in LPS-treated rat (p<0.05), in spite of L-NAME, aminoguanidine pretreatment was failed to increase contractile forces in control and LPS-treated rats. CONCLUSIONS: From these results, viewed from maintenance of vasomotor tone in septic state, it is suggested that hydroxocobalamin may be candidate for vasopressor during usual induction of general anesthesia.

Wakefulness during Cesarean Section after General Anesthetic Induction until Delivery Tested by Isolated Forearm Technique / 대한마취과학회지

BACKGROUND: As undergoing general anesthesia for Cesarean Section, we usually maintain a light anesthesia until delivery. It provokes the high incidence of waketulness for the mothers. We surveyed the incidence of maternal wakefulness when thiopental was used as an induction agent. METHODS: Forty pregnant women (ASA class I or II) at term who underwent general anesthesia and cesarean section received thiopental, 4mg/kg. As the 'isolated forearm technique', a pressure cuff was inflated to isolate one arm from the the effects of succinylcholine so that wakefulness during anesthesia could be assessed by asking the patient to move her hand. To assess wakefulness,the patient was commanded to squeeze the investigator's hand a specified number of times. If the patient promptly squeezed the investigator's hand the appropriate number of times, the command was repeated but a different number of times specified. Only if the patient responded correctly both times, then we noted as a positive response. This test was repeated at 1 minute intervals beginning 1 minute after thiopental injection through the delivery. RESULTS: Five of the forty patients (12.5%) showed wakefulness. Twenty nine of the forty patients showed 'reaching movements'. One patient showed both wakefulness and 'reaching movements'. CONCLUSIONS: When we undergo general anesthesia for Cesarean Section, especially using thiopental as an induction agent, we should consider the maternal wakefulness seriously.