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.

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).

Etiology of Failure in Epidural Anesthesia: Transforaminal Escape of Epidural Catheter: Two cases / 대한마취과학회지

One of the most common mechanisms of failure of epidural anesthesia is the misplacement of a catheter. We present two cases of transforaminal escape of catheter which occurred accidentally during lumbar epidural anesthesia. Epidural catheter was inserted to a depth of 4.5 cm and 3.5 cm respectively, then 2% lidocaine 25 ml were injected slowly into the catheter. No analgesia was found except anterior knee area, so Iohexol dye was injected through the catheter for X-ray determination. The epidurogram showed the catheter, which passed through the intervertebral foramen, was to lie outside the epidural space in the paravertebral tissue. Because of the random direction and migration of epidural catheter, we suggest an epidural catheter should be inserted 3cm into the epidural space. Epidurogram with a small dose of contrast material is advisable in the cases of unsatisfactory effect of epidural block, or when some adverse reactions are noted after block.