The Effect of Induced Hypotension on Intraoperative Blood Loss during Spinal Surgery / 대한마취과학회지

BACKGROUND: This study was performed to evaluate whether the degree of hypotension influences blood loss during spinal surgery. METHOD: Fifty patients undergoing only one level spinal fusion were assigned to one of three groups. In group 1 (n = 14), the systolic blood pressure (SBP) was maintained at 100 120 mmHg with enflurane. In groups 2 (n = 18) and 3 (n = 18), the SBP were maintained at 80 100 and 60 80 mmHg, respectively. Hydralazine and esmolol were used in the hypotensive groups. RESULTS: Blood losses during operation in groups 2 (554 +/- 287 ml) and 3 (456 +/- 162 ml) were significantly lower than in group 1 (1141 +/- 690 ml) (P < 0.05), although there was no significant difference between groups 2 and 3. The percentage of patients receiving transfusions during the operation in groups 1 and 2 were 57.1 and 5.6%, respectively. CONCLUSIONS: The results show that a moderate reduction in SBP (80 - 100 mmHg) reduces blood loss by more than half in comparison to a mild reduction in SBP (100 - 120 mmHg). However, a severe reduction in SBP (60 - 80 mmHg) does not increase the reduction in blood loss in comparison to moderate hypotension.

ED95 of Esmolol for Protection of Tachycardia and Systolic Hypertension by Endotracheal Intubation in Anesthetic Induction with Enflurane, Nitrous Oxide, Thiopental and Fentanyl / 대한마취과학회지

BACKGROUND: Esmolol has been used combined with small dose of fentanyl to prevent tachycardia and hypertension induced by tracheal intubation, but there has been few studies about the appropriate doses of esmolol when used combined with fentanyl. METHODS: According to esmolol dose, 140 patients were randomly allocated to 7 groups of 20 patients. After 2 microgram/kg of fentanyl, 4 mg/kg of thiopental and 0.12 mg/kg of vecuronium were intravenously administered, mask ventilation for 3 minutes with enflurane, nitrous oxide and oxygen was followed. Then one of the doses of esmolol, 0, 0.2, 0.3, 0.45, 0.6, 0.8 or 1.0 mg/kg was administered. Ninty seconds later, tracheal intubation by direct laryngoscopy was performed. After then heart rate was monitored continuously and blood pressure was measured 5 times with 1 minute interval. The highest heart rate and systolic blood pressure were recorded. We calculated the doses of esmolol which reduce the incidence of tachycardia (increased above 100 bpm or by more than 40% of preinduction level) and systolic hypertension (increased above 170 mmHg or by more than 40% of preinduction level) below 5% respectively. RESULTS: The ED95 of esmolol for prevention of tachycardia induced by tracheal intubation was 0.56 mg/kg (95% CI: 0.44-0.81 mg/kg). But the incidence of systolic hypertension was so low even without esmolol injection that the esmolol dose was not significant factor. CONCLUSIONS: In anesthetic induction and tracheal intubation with enflurane, nitrous oxide, thiopental, vecuronium, and fentanyl 2 microgram/kg, esmolol 0.56 mg/kg was ED95 of preventing tachycardia. But the incidence of systolic hypertension was acceptably low even without esmolol injection.

The Effects of a Combination of Fentanyl and Esmolol on Hemodynamic Responses after Endotracheal Intubation in Hypertensive Patients / 대한마취과학회지

BACKGROUND: To prevent hypertension and tachycardia after endotracheal intubation, esmolol and low-dose fentanyl have been used and it was reported that the combination of them was more effective than either in normotensive patients. However there have been few studies in this regard using hypertensive patients. Therefore, the author evaluated the effects of a combination of esmolol and low-dose fentanyl on hemodynamic responses after laryngoscopy and endotracheal intubation in hypertensive patients. METHODS: Thirty hypertensive patients were premedicated with midazolam and glycopyrrolate. Fentanyl 2 microgram/kg and esmolol 1 mg/kg were injected before induction of anesthesia. Thiopental sodium 3 5 mg/kg and succinylcholine 1 mg/kg were used for the induction of anesthesia. Endotracheal intubation was performed at 5 minutes after fentanyl injection. Thereafter 50% nitrous oxide in oxygen and 2 vol% enflurane were inhaled. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP) and heart rate (HR) were measured before fentanyl injection (base), before intubation, and at 1, 3 and 5 minutes after intubation. RESULTS: At 1 minute after intubation, SBP and MAP did not change significantly, but DBP increased slightly compared to base (P 170 mmHg) developed in 2 patients at 1 minute after intubation, and hypotension (SBP 100 bpm) developed in 2 patents at 1 minute after intubation and bradycardia (HR< 50 bpm) in 1 patient at 5 minutes after intubation. CONCLUSIONS: In treated hypertensive patients, the use of a combination of fentanyl 2 microgram/kg and esmolol 1 mg/kg is a useful method to attenuate hypertension and tachycardia after endotracheal intubation.

Comparison of Verapamil and Esmolol for Controlling the Blood Pressure and Heart Rate to Tracheal Intubation According to the Different Anesthetic Induction Agents / 대한마취과학회지

BACKGROUND: Antihypertensive agents such as verapamil and esmolol are well known for their effects of hemodynamic stabilization on tracheal intubation. But hemodynamic discrepancies in these agents may result from different techniques of anesthetic induction. The aim of the present study was to compare and evaluate their efficacy in controlling hemodynamic responses to tracheal intubation under the different anesthetic induction agents. METHODS: Seventy-two patients, ASA physical status I or II, were randomly assigned to one of six groups (n = 12 each): a Thiopental-Saline (T-S) group and a Propofol-Saline (P-S) group in saline 10 ml; a Thiopental-Verapamil (T-V) group and a Propofol-Verapamil (P-V) group in verapamil 0.1 mg/kg; a Thiopental-Esmolol (T-E) group and a Propofol-Esmolol (P-E) group in esmolol 1 mg/kg according to the induction agents, thiopental or propofol. Anesthesia was induced with thiopental 5 mg/kg or propofol 2 mg/kg intravenous, respectively. Next, saline, verapamil and esmolol were administered as a bolus, and were immediately followed by succinylcholine 1.5 mg/kg. Tracheal intubation was carried out 60 s and 90 s after the intravenous injections of verapamil and esmolol, respectively. Systolic and diastolic blood pressure and heart rate were measured before induction and every minute for 5 minutes after tracheal intubation. RESULTS: There was a significant attenuation in systolic and diastolic arterial pressure after tracheal intubation in the verapamil groups compared to the esmolol groups. Heart rates were significantly lower in the esmolol groups than in the verapamil groups after tracheal intubation. CONCLUSIONS: Verapamil 0.1 mg/kg and esmolol 1 mg/kg attenuated increases in blood pressure and heart rate after tracheal intubation. The different anesthetic induction agents did not influence the hemodynamic effects of verapamil and esmolol on tracheal intubation.

Comparison of Verapamil and Esmolol for Controlling the Blood Pressure and Heart Rate to Tracheal Intubation According to the Different Anesthetic Induction Agents / 대한마취과학회지

BACKGROUND: Antihypertensive agents such as verapamil and esmolol are well known for their effects of hemodynamic stabilization on tracheal intubation. But hemodynamic discrepancies in these agents may result from different techniques of anesthetic induction. The aim of the present study was to compare and evaluate their efficacy in controlling hemodynamic responses to tracheal intubation under the different anesthetic induction agents. METHODS: Seventy-two patients, ASA physical status I or II, were randomly assigned to one of six groups (n = 12 each): a Thiopental-Saline (T-S) group and a Propofol-Saline (P-S) group in saline 10 ml; a Thiopental-Verapamil (T-V) group and a Propofol-Verapamil (P-V) group in verapamil 0.1 mg/kg; a Thiopental-Esmolol (T-E) group and a Propofol-Esmolol (P-E) group in esmolol 1 mg/kg according to the induction agents, thiopental or propofol. Anesthesia was induced with thiopental 5 mg/kg or propofol 2 mg/kg intravenous, respectively. Next, saline, verapamil and esmolol were administered as a bolus, and were immediately followed by succinylcholine 1.5 mg/kg. Tracheal intubation was carried out 60 s and 90 s after the intravenous injections of verapamil and esmolol, respectively. Systolic and diastolic blood pressure and heart rate were measured before induction and every minute for 5 minutes after tracheal intubation. RESULTS: There was a significant attenuation in systolic and diastolic arterial pressure after tracheal intubation in the verapamil groups compared to the esmolol groups. Heart rates were significantly lower in the esmolol groups than in the verapamil groups after tracheal intubation. CONCLUSIONS: Verapamil 0.1 mg/kg and esmolol 1 mg/kg attenuated increases in blood pressure and heart rate after tracheal intubation. The different anesthetic induction agents did not influence the hemodynamic effects of verapamil and esmolol on tracheal intubation.

Comparison of Esmolol and Thoracic Epidural Block in Induced Hypotension / 대한마취과학회지

BACKGROUND: Induced hypotension reduces blood loss in the surgical field and provides better visibility. For induced hypotension, many methods have been used. Recently esmolol is favored in induced hypotension because of its short action and easy controlability, but thoracic epidural block is seldom used in induced hypotension. So we compared the effect of esmolol and thoracic epidural block in induced hypotension. METHOD: Patients scheduled for spinal posterior fusion under general anesthesia were randomly divided into two groups. In thoracic epidural group (Group I, 20 patients), 8~10 ml of 2% lidocaine was injected into the epidural catheter located in T6-7 interspace in a bolus. In esmolol group (Group II, 20 patients), 0.5 mg/kg of esmolol received as loading dose and 50~150 microgram/kg/min infused continuously. We measured mean arterial pressure, central venous pressure, heart rate, amounts of administrated fluids, urine output and VAS score. RESULT: There were no statistically significant differences between the two groups in amounts of bleeding, administered fluid, urine output. The elapsed time to reach the state of induced hypotension (MAP 55~65 mmHg) is 15.1 2.4 min after lidocaine injection in Group I and 6.1 2.7 min after esmolol injection in Group II (p<0.05). There were statistically significant differences between two groups in mean arterial pressure in 10 min after the injection (p<0.05). But there was apparent difference in VAS score in postoperative 1 hrs, 2 hrs and 6 hrs (p<0.05). CONCLUSION: Thoracic epidural block is another method for induced hypotension. And postoperative pain control can be easily achieved by injection through epidural catheter.

Appropriate Dose of Esmolol for Protection of Tachycardia and Hypertension by Endotracheal Intubation / 대한마취과학회지

BACKGROUND: Esmolol has been recommended to prevent tachycardia and hypertension induced by tracheal intubation in several studies, but these studies are based on mean values of changes of vital signs. Therefore, the recommended doses are not guaranteed to be precise effective dose. METHODS: According to esmolol dose, 140 patients were randomly alldegrees Cated to 7 groups of 20 patients. After intravenous thiopental and vecuronium followed by mask ventilation of 3 minutes with enflurane, nitrous oxide and oxygen, one of the dosages of esmolol 0, 0.2, 0.3, 0.45, 0.5, 0.6, 0.8 or 1.0 mg/kg was administered. Ninty seconds later, tracheal intubation by direct laryngoscopy was performed. After then heart rate was monitored continuously and blood pressure was measured 5 times at intervals of 1 minute. The highest heart rate and systolic blood pressure were recorded. If the highest heart rate was beyond 100/min or highest systolic blood pressure was beyond 170 mmHg, we regarded this cases as 'unprotected' case. By logistic regression, we calculated the doses of esmolol which reduce the incidence of tachycardia, systolic hypertension and unprotection below 5% respectively. RESULTS: The appropriate doses of esmolol for prevention of tachycardia, systolic hypertension and 'unprotection' were 0.95 mg (95% CI: 0.77~1.33 mg), 0.38 mg (95% CI: 0.21~1.05 mg) and 0.93 mg (95% CI: 0.78~1.23 mg) respectively. CONCLUSIONS: In anesthetic induction and tracheal intubation with thiopental and vecuronium, esmolol 0.78~1.23 mg/kg was appropriate for preventiion of tachycardia ( > 100 bpm) and systolic hypertension ( > 170 mmHg).

Comparison of Post-operative Liver Function after Induced Hypotention between Thoracic Epidural Bldegrees Ckade and Esmolol / 대한마취과학회지

BACKGROUND: Induced hypotension reduces blood loss in the surgical field and provies better visibility. May methods have been used for induced hypotension. Recently Esmolol is favored in induced hypotension because of its short action of sympathetic beta-1 receptor antagonist and easy to control. Thoracic epidural bldegrees Ck can provide cadiovascular stability in induced hypotension. The purpose of the study is to compare postoperative liver function after induced hypotension between thoracic epidural bldegrees Ckade and esmolol combined with general anesthesia with isoflulane. METHOD: Fourty patients scheduled for spinal posterior fusion under general anesthesia were randomly divided into two groups. In thoracic epidural bldegrees Ckade group(Group I, 20 patients), 8~10 ml of 2% liddegrees Caine was injected into the epidural catheter ldegrees Cated in T6~7 interspace in a bolus. In Esmolol group(Group II, 20 patients) received 0.5 mg/kg as loading dose and 50~150 microgram/kg/min continuously. We measured preoperative and postoperative 1, 3, 5, 7 day's serum glutamic-oxaloacetic transaminase(SGOT), serum glutamic-pyruvate transaminase(SGPT) and alkaline phosphatase(ALP). RESULT: In the thoracic epidural bldegrees Ckade group, there was statistically significant increase of SGOT level above normal range on postoperative 1 day, which decreased on postoperative 3 and 5 day(p<0.05). But it was within normal range on postoperative 7 day. SGPT was increased within normal range. Similarly, in the esmolol group, there was statistically significant increase of SGOT level above normal range on postoperative 1 day, which decreased on postoperative 3 and 5 day(p<0.05). But it was within normal range on postoperative 7 day. SGPT was increased within normal range. The level of ALP was increased within normal range in both groups. There was no statistically significant difference in liver function between two groups. CONCLUSION: We consider that postoperative liver function is little influenced with induced hypotension by thoracic epidural bldegrees Ckade and esmolol combined with general anesthesia with isoflurane.

Comparison of the Blood Loss during and after Spinal Surgery under Hypotensive Anesthesia and Effects of Furosemide on the Urine Output during Hypotensive Anesthesia for Spinal Surgery / 대한마취과학회지

BACKGROUND: The induced hypotensive anesthesia may produce serious complications related to central nervous system, heart, liver, kidney and eyes. In this study, the blood loss during and after operation were compared to evaluate the delayed effect of hypotension on postoperative bleeding and also, the urine output was measured in control group and furosemide treated group, to investigate the effect of furosemide on the protection of kidney function. METHODS: Forty patients undergoing spinal surgery were evaluated and the hypotension was induced by the combination of hydralazine, esmolol and propranolol under enflurane anesthesia. During hypotensive anesthesia, the systolic arterial blood pressure was maintained between 65 to 75 mmHg. I compared the arterial blood gas analysis, plasma protein, albumin and calcium level, blood urea nitrogen (BUN), creatinine and complete blood count (CBC) before, durng and after hypotensive anesthesia. And also, the volume of blood loss and the units of transfused blood were measured intraoperatively and postoperatively. To investigate the effect of furosemide on the protection of kidney function, patients were randomly divided to contol group (n=20) and furosemide group (n=20). In furosemide goup, 0.1 mg/kg was administered intravenously and the urine output was measured during and after hypotensive anesthesia in both groups. RESULTS: The systolic arterial blood pressure during hypotensive anesthesia was maintained between 65 to 75 mmHg as planned in all forty patients. The average blood loss during and after operation were 769+/-541 and 786+/-397 ml, respectively and the average total blood loss was 1555+/-784 ml. The average units of transfused packed red cell during and after operation were 2.6+/-0.8 and 1.9+/-0.4 units, respectively, and the average total transfused units were 2.3+/-0.8 units. In both control and furosemide treated groups, all forty patients showed oliguria during first two hours after starting hypotensive anesthesia but urine outputs were recovered after the end of hypotensive anesthesia in both groups. During and after hypotensive anesthesia, pH was slightly but significantly decreased. Plasma protein, albumin, calcium and BUN were decreased during and after hypotensive anesthesia compared with before hypotensive anesthesia values. During and after hypotensive anesthesia, platelet count was decreased significantly but white cell count was increased. Severe oliguria was noted during hypotensive anesthesia in both groups and no serious complication related to hypotensive anesthesia was found. CONCLUSIONS: In this study, the volume of blood loss after anesthesia was almost same as that during anesthesia. And the administration of furosemide 0.1 mg/kg did not prevent oliguria during hypotensive anesthesia.

Comparison of Sodium Nitroprusside and Esmolol Induced Hypotension for Total Hip Arthroplasty / 대한마취과학회지

BACKGROUND: Esmolol is a short acting sympathetic beta receptor antagonist, and it was successfully applied to induced hypotension. Esmolol lowers blood pressure by decreasing cardiac output, and does not cause vasodilation. This property of esmolol may help to decrease bleeding during induced hypotension. In this study, we tried to elucidate the effect of esmolol on induced hypotension for total hip arthroplasty. METHOD: Twenty patients receiving total hip arthroplasty were randomly divided to two groups. Esmolol group (10 patients) received esmolol as a hypotensive agent, and sodium nitroprusside (SNP) group (10 patients) received SNP as a hypotensive agent. We measured arterial blood gas analysis, vital sign, amounts of bleeding, amounts of transfusion and administered fluid, and various laboratory findings. RESULTS: Induced hypotension was successfully performed in either esmolol and SNP group. Heart rate increased by SNP, and decreased by esmolol. There were no statistically significant differences between the two groups in amounts of bleeding, amounts of transfusion or administered fluid, and laboratory findings. Arterial oxygen tension was relatively constant in esmolol group, but decreased in SNP group. CONCLUSION: Esmolol can be used as a single hypotensive agent during induced hypotension without significant side effects during total hip arthroplasty.

Clinical Study of the Onset Time of Esmolol / 대한마취과학회지

BACKGROUND: The purpose of this study was to compare the time course of the bradycardia and hypotensive effects of esmolol. METHODS: Thirty patients who undergoing gynecologic operation were anesthetized with nitrous oxide and enflurane. After the steady state of anesthesia was achieved, esmolol 500microgram/kg for 1 minute followed by 25, 50, or 100microgram/kg/min for 60minuts infused by intravenous catheter. Heart rate, mean arterial pressure, cardiac index, stroke volume, and systemic vascular resistance was measured by 1, 3, 5, 10, 15, 20, 25, 30, 45, and 60 minutes. RESULTS: Heart rate was changed abruptly within 3 to 5 minutes, and decreased rapidly for 15minutes. Mean arteral pressure was decreased rapidly for 30 minutes, but slower than heart rate. Cardiac index was decreased rapidly for 20 minutes and differed significantly on the dose of 25, 50, 100microgram/kg. Stroke volume was decreased for 30 minutes, and systemic vascular resistance was increased rapidly for 10 minutes. It was decided the onset time that was expressed 90% of ultimate response of esmolol effect, and was calculated in each group. The onset time of heart rate of esmolol 25, 50, 100microgram/kg were 8.0 +/- 4.1, 4.8 +/- 2.3, 8.1 +/- 4.4 minutes, the time of mean arterial pressure were 30.0 +/- 7.5, 21.1 +/- 6.2, 19.9 +/- 7.8 minutes, and the time of cardiac index were 25.1 +/- 4.7, 14.8 +/- 5.0, 14.2 +/- 4.6 minutes. Thus heart rate, mean arterial pressure, cardiac index, stroke volume, and systemic vascular resistance responses of administration of esmolol did not occur with equal rapidity. CONCLUSIONS: Thus although esmolol has an ultrashort kinetic half life, only the heart rate effect can be considered to have an ultrashort onset.

The Effect of Continuous Intravenous Infusion of Esmolol on Heart Rate and Blood Pressure after Ketamine Induction and Endotracheal Intubation / 대한마취과학회지

BACKGROUND: This study was designed to evaluate the effect of continuous intravenous infusion of esmolol on the heart rate and blood pressure, after ketamine induction and endotracheal intubation. METHODS: With informed consent, forty patients with ASA physical status 1 were randomly divided into two groups. Esmolol group received the continuous intravenous infusion of esmolol (at 500 microgram/kg/min for 1 minute as a loading dose and at 300 microgram/kg/min until 7 minutes after endotracheal intubation as a maintenance dose) and saline group received normal saline at the same volume-rate. 2 mg/kg of ketamine and 0.15 mg/kg of vecuronium were given at 4 minutes after the test drugs. Intubation was performed at 3 minutes after the induction. The changes of blood pressure, heart rate and rate pressure product were measured at different time intervals (preinduction, preintubation, immediately after intubation and postintubation 1, 3, 5 and 7minutes). RESULTS: In the esmolol group, the changes of systolic blood pressure, diastolic blood pressure, heart rate and rate pressure product were significantly attenuated when compared with the saline group. The changes in heart rate at preintubation and intubation were not statistically significant when compared with the baseline value within the esmolol group. CONCLUSIONS: It is concluded that the infusion of esmolol attenuated the hemodynamic changes following ketamine induction and endotracheal intubation, but it is still needed to find the dosage of esmolol.

Effect of Esmolol on Serum Potassium Changes Induced by Succinylcholine / 대한마취과학회지

BACKGROUND: The purpose of this study was to determine whether esmolol augmented the increase in serum K+ following administration of succinylcholine. METHODS: Forty patients were randomly divided esmolol group (n=20) and control group (n=20). The esmolol group received a 1 minute rapid infusion of 500 mcg/kg/min followed by a continuous infusion of 200 mcg/kg/min for 4 minutes before administration of succinylcholine. Serum potassium level, mean arterial blood pressure and pulse rate were measured prior to induction(baseline) and 1, 3, 5, 10, 15, 30, 45, 60, 75, 90 minutes after administration of succinylcholine. RESULTS: Serum potassium level was significantly higher in esmolol group after 3 and 15 minutes after succinylcholine than control group. Mean arterial blood pressure was not significantly different between two groups except 10 minute but the pulse rate significantly lower 1, 3, 5, 10 and 15 minutes in esmolol group than control group. CONCLUSIONS: Esmolol does not significantly elevate serum potassium level in clinical use(1 minute infusion of 500 mcg/kg/min followed by infusion of 200 mcg/kg/min for 4 minutes) after administration of succinylcholine. So succinylcholine can be used safely in the presence of beta-1-selective adrenergic blockade. And esmolol can attenuate more effectively increase of pulse rate than mean arterial pressure.

Bronchospasm After Intravenous Esomolol Injection with Rapid Sequence Induction for Preeclamptic Patient: Case report / 대한마취과학회지

Esmolol is rapid ultrashort-acting, cardioselective beta1-adrenergic blocker and that is used for attenuation of acute hypertension associated with rapid sequence induction of general anesthesia. A 35-year-old severe preeclamptic patient was scheduled for elective cesarean section. After preoxygenation, anesthesia induced with using penthotal sodium 250 mg, esmolol 25 mg, and succinylcholine 62.5 mg for endotrachial intubation. We detected to increase airway resistance during manual ventilation. Breathing sound was auscultated wheezing and ronchi. And then cyanosis was developed and oxygen saturation was decreased to below 75%. After 20 min, patient's color was returned to pink and patient's self-respiratory function was good. Bronchospasm occured because that beta-adrencergic blockade with esmolol, by leaving the parasympathetic and alpha-adrencrgic influence relatively unopposed. We report bronchospasm after esmolol 25 mg was injeected for attenuation of acute hypertensive response for cesarean section of preeclamptic patient with rapid sequence induction of general anesthesia.

Bronchospasm After Intravenous Esomolol Injection with Rapid Sequence Induction for Preeclamptic Patient: Case report / 대한마취과학회지

Esmolol is rapid ultrashort-acting, cardioselective beta1-adrenergic blocker and that is used for attenuation of acute hypertension associated with rapid sequence induction of general anesthesia. A 35-year-old severe preeclamptic patient was scheduled for elective cesarean section. After preoxygenation, anesthesia induced with using penthotal sodium 250 mg, esmolol 25 mg, and succinylcholine 62.5 mg for endotrachial intubation. We detected to increase airway resistance during manual ventilation. Breathing sound was auscultated wheezing and ronchi. And then cyanosis was developed and oxygen saturation was decreased to below 75%. After 20 min, patient's color was returned to pink and patient's self-respiratory function was good. Bronchospasm occured because that beta-adrencergic blockade with esmolol, by leaving the parasympathetic and alpha-adrencrgic influence relatively unopposed. We report bronchospasm after esmolol 25 mg was injeected for attenuation of acute hypertensive response for cesarean section of preeclamptic patient with rapid sequence induction of general anesthesia.