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.

Tracheal Rupture Following Insertion of Double-Lumen Endobronchial Tube during Bronchoesophageal Fistular Repair: A case report / 대한마취과학회지

Tracheobronchial rupture following tracheal intubation with double-lumen endobronchial tube (DLT) is a rare complication, but may result in a massive air leakage with resultant pneumothorax, mediastinal emphysema and extensive subcutaneous emphysema in the postoperative period. We report a case of sustained laceration of the posterior membranous part of the trachea possibly due to overinflation of the double-lumen endobronchial tube. A 76-year-old, 45 kg, female was scheduled for a repair of her bronchopleural fistula. Following induction of anesthesia, intubation was performed with Robertshaw's DLT, and a tracheal cuff was inflated with 6 ml of air, but the sound of an air leak was heard coming from the patient's mouth during controlled ventilation. A further 5 ml of air was added 1 ml at a time into the tracheal cuff but the air leak sound continued. At that point, the sound was considered to originate from the bronchopleural fistula rather than from lack of sufficient air. After a thorough deflation of the tracheal cuff, 6 ml of air was reinjected and the operation was resumed. A 4 cm split was unexpectedly noticed in the posterior wall of the trachea during the operation and was repaired without complication.

Effects of both Clonidine Premedication and Esmolol Administration on the Hemodynamic Changes by Tracheal Intubation / 대한마취과학회지

BACKGROUND: Tracheal intubation by direct laryngoscopy induces frequently transient hypertension, tachycardia and arrhythmia. The purpose of this study was to examine the effect of esmolol and clonidine in attenuating the changes of blood pressure and heart rate by tracheal intubation. METHODS: Eighty patients were randomly divided into four groups: Group 1 (control , n=20), Group 2 (esmolol 0.5 mg/kg IV, n=20), Group 3 (clonidine 4 mcg/kg PO, n=20) and Group 4 (clonidine 4 mcg/kg PO and esmolol 0.5 mg/kg IV, n=20). The clonidine premedication were given orally with a sip of water 90 minutes before induction of anesthesia. Anesthesia was induced with thiopental 5 mg/kg, vecuronium 0.1 mg/kg, 50% nitrous oxide in oxygen and 2 vol % enflurane. After 5 minutes, tracheal intubation was performed. Patients in the group 2 and group 4 were given esmolol 0.5 mg/kg 90 seconds prior to tracheal intubation. Blood pressure and heart rate were measured at ward, preinduction, preintubation, immediately after intubation, 1, 3 and 5 minutes after intubation. RESULTS: After tracheal intubation, the increase in systolic blood pressure was supressed significantly in the clonidine-treated patients (Group 3, Group 4) compared with control group (p<0.05). The attenuating effect on increase of mean arterial pressure(MAP) was sustained longer in group 4 than group 3. Heart rate increased after tracheal intubation in all groups, but were markedly increased in the control group (p<0.05). The differences of MAP which measured at preinduction and immediately postintubation were smaller in group 4 than control group (p<0.05). The differences of heart rate which measured at preinduction and immediately postintubation were smaller in group 4 than group 1 or group 3 (p<0.05). CONCLUSIONS: Esmolol 0.5 mg/kg given as bolus, is effective for controlling the increase of heart rate but not in attenuating increase of blood pressure. Oral clonidine is effective for controlling the increase of blood pressure but not in attenuating increase of heart rate. Therefore esmolol combined with oral clonidine results in effective control of both heart rate and blood pressure.

Pneumomediastinum and Subcutaneous Emphysema after Use of Metallic Endotracheal Tube for Laser Operation: A case report / 대한마취과학회지

We report a case of pneumomediastinum, subcutaneous emphysema, and mild pneumothorax that occurred after endotracheal intubation with a metallic endotracheal tube for the laser operation. Fortunately, pneumomediastinum and subcutaneous emphysema were self-limited. But potentially life-threatening events such as upper airway obstruction, tension pneumothorax, pneumopericardium, mediastinitis might be possible. These complications may result from mucosal perforation of upper airway. The use of a tube with rigid and relatively narrower internal diameter than polyvinylchloride endotracheal tube, tough endotracheal intubation technique, high peak inspiratory pressure, suction technique and negative pressure are included as complication factors.

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).

Inhibitory Effect of Nicardipine on Cardiovascular Stimulation by Tracheal Intubation / 대한마취과학회지

BACKGROUND: Direct laryngoscopy and tracheal intubation frequently induce transient hypertension, tachycardia and arrhythmia. This study was to evaluate the effect of nicardipine on the changes of the blood pressure and heart rate induced by direct laryngoscopy and tracheal intubation. METHODS: Sixty patients were randomly divided into three groups: Group 1 (nicardipine 0.02 mg/kg, n=20), Group 2 (diltiazem 0.2 mg/kg, n=20), Group 3 (normal saline 3 cc, n=20). Two minutes after intravenous injection of 2 mcg/kg of fentanyl, thiopental 5 mg/kg and nicardipine or diltiazem or normal slaine was administered intravenously. Then succinylcholine 1.5 mg/kg was administered. One minute after succinylcholine injection, direct laryngoscopy and tracheal intubation was done and vecuronium 0.1 mg/kg was injected. Anesthesia was maintained with 50% nitrous oxide in oxygen and 2 vol % of enflurane. Blood pressure and heart rate were measured at the period of preintubation, immediately after intubation, 1, 3 and 5 minutes following intubation by noninvasive method. RESULTS: After tracheal intubation, the increase of systolic blood pressure was supressed significantly in nicardipine and diltiazem group compared with control group (nicardipine group 11%, diltiazem group 13%, control group 24%). The increase of heart rate was greatest in nicardipine group (nicardipine group 38% diltiazem group 29%, control group 20%). CONCLUSIONS: Nicardipine was effective in attenuating pressor responses to laryngoscopy and intubation, but in nicardipine group, increase of heart rate was greater than control group.

Iatrogenic Aspiration of a Broken Metallic Stylet: A case report / 대한마취과학회지

Complications of tracheal intubation are well documented. However, iatrogenic aspiration of a broken metallic stylet following tracheal intubation has been infrequently reported. A 60-year-old woman, 10 days after shoulder arthroscopic surgery under endotracheal general anesthesia, was admitted to our hospital because of right chest pain. Chest radiographs showed a 8 cm length of metallic foreign body in the lower lobe of the right lung. Attempts at retrieval, including thoracoscopy, were unsuccessful. Open thoracostomy was performed. The removed foreign body was a part of metallic stylet. We report a case of iatrogenic aspiration of a broken metallic stylet.

Effects of Esmolol on the Responses to Awake Fiberoptic Nasotracheal Intubation / 대한마취과학회지

BACKGROUND: It has recently been shown that esmolol provided consistent and reliable protection against increase in both heart rate and systolic blood pressure accompanying laryngoscopy and intubation. This study was therefore designed to establish whether esmolol was as effective in controlling the responses to awake fiberoptic tracheal intubation as it was in controlling the responses to traditional intubation and to assess the effect of esmolol for conditions of intubation, sedation, respiratory system during fiberoptic laryngoscopy and intubation. METHODS: Thirty patients, ASA physical status I-II, scheduled for oral and maxillofacial surgery, were randomly assigned to receive preintubation dose of either fentanyl 100 microgram(Group F) or fentanyl 50 microgram and esmolol 100 mg(Group E). And during awake fiberoptic nasotracheal intubation, heart rate, systolic and diastolic arterial pressures, minimal peripheral oxygen saturation, sedation score, intubation condition and time were recorded. RESULTS: There were no significant differences in arterial blood pressures, sedation score, intubation condition and time. But the change of heart rate in Group E was significantly less at 1 minite and 2 minites after the start of tracheal intubation and in Group F, minimal peripheral oxygen saturation was significantly reduced and two patients in Group F were hypoxemic and apneic. CONCLUSIONS: The present results show that esmolol provides attenuation of the change of heart rate by awake fiberoptic nasotracheal intubation and minimize the risk of apnea and hypoxia due to combination of fentanyl with midazolam.

Effects of Lidocaine, Fentanyl, and Esmolol on Blood Pressure and Heart Rate Changes owing to Endotracheal Intubation during Propofol Induction / 대한마취과학회지

BACKGROUND: Laryngoscopy and endotracheal intubation for general anesthesia cause tachycardia and hypertension due to sympathetic stimulation. The purpose of this study is comparison of effects of lidocaine, fentanyl, and esmolol on blood pressure and heart rate changes owing to tracheal intubation during propofol induction. METHODS: Pateints were randomly received one of the following study drug intravenously prior to induction : Group 1(normal saline 5 ml, n=20) ; Group 2 (lidocaine 1.5 mg/kg, n=20) ; Group 3 (fentanyl 2 microgram/kg, n=20) ; Group 4 (esmolol 1.0 mg/kg, n=20). Anesthesia was induced with propofol 2.5 mg/kg IV and then maintained with 50% nitrous oxide in oxygen and 1.0 vol% isoflurane. Systolic and diastolic blood pressure and heart rate were measured preinduction, after induction, immediately after intubation, and 1, 3, 5, 7, 9, 11 minutes following intubation. RESULTS: After intubation, the increase in systolic blood pressure and heart rate were blunted significantly compared with the control group in the group 3 (p<0.05). In the group 4, the increase in blood pressure was not suppressed but modified and tachycardia was not prevented after intubation. CONCLUSIONS: Fentanyl 2 microgram/kg was suppressed blood pressure changes and effective in attenuating tachycardia during propofol induction compare with control and lidocaine groups. Esmolol 1.0mg/kg was effective in attenuating blood pressure changes owing to tracheal intubation.