The effect of intravenous labetalol administration on hemodynamic responses during desflurane inhalation / 대한마취과학회지

BACKGROUND: Inspired concentrations of desflurane > or = 1 minimum alveolar anesthetic concentration (MAC) have been related to sympathetic stimulation such as hypertension and tachycardia. The current study examined whether labetalol, an alpha1 and beta-adrenergic antagonist would blunt these hemodynamic responses. METHODS: Fifty-four ASA physical status I patients, aged 20-60 years, were enrolled in this study. The patients were randomly divided into 2 groups. The breathing circuit was primed with an end-tidal desflurane concentration of 1.2 MAC in 6 L/min O2. Normal saline 5 ml or labetalol 0.3 mg/kg was injected into groups S and L respectively. After 5 minutes, anesthesia was induced with intravenous etomidate 0.2 mg/kg and vecuronium 0.1 mg/kg. Each patient inhaled desflurane through a tight fitting facemask. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and end-tidal concentration of desflurane (et-des) were measured at 5 minutes after saline or labetalol injection (baseline) and every 1 minute for 5 minutes after desflurane inhalation and for 2 minutes after intubation. RESULTS: In the saline injection group (group S), desflurane inhalation increased heart rate and blood pressure, while labetalol 0.3 mg/kg attenuated the heart rate and blood pressure increase in group L. After tracheal intubation, heart rate and blood pressure were significantly lower in group L than in group S. CONCLUSIONS: These results demonstrate that administration of intravenous labetalol is effective in attenuating tracheal intubation and desflurane-induced hemodynamic responses.

The effectiveness of the Bonfils intubation fibrescope for endotracheal intubation / 대한마취과학회지

BACKGROUND: This study was conducted to evaluate the effectiveness of the Bonfils intubation fibrescope for endotracheal intubation. METHODS: 78 patients aged 21 to 85 years underwent direct laryngoscopy and the laryngoscopic view was then graded according to the Cormack & Lehane classification. The patients were subsequently intubated with a Bonfils intubation fibrescope and the success rate for tracheal intubation, time to intubation, number of attempts and adverse effects were recorded. In addition, the thyromental distance was recorded following the orotracheal intubation. RESULTS: The success rate for tracheal intubation was > 95% in patients graded 1 to 3 and 63.5% in patients with a grade of 4. The time to intubation was significantly faster in patients graded 1 to 3 than in those with a grade of 4 (175.2 +/- 137.1) (P < 0.01). Third attempts were required more often in patients with a higher grade. The number of patients with a SpO2 < 90% was below 5% in patients with a grade of 1 to 3 and 58.8% in patients with a grade of 4. CONCLUSIONS: The Bonfils intubation fibrescope is an effective instrument for endotracheal intubation in patients with a grade of 1 to 3, however, tracheal intubation using the Bonfils intubation fibrescope was unsuccessful in some patients with a grade of 4. Therefore, other effective instruments should be considered for use in cases of failed direct laryngoscopy or in patients for which a difficult airway is predicted.

The Effects of Preoperative Sprayed 10% Lidocaine on the Hemodynamic Response during Suspension Microlaryngeal Surgery / 영남의대학술지

PURPOSE: It is well known that suspension microlaryngeal surgery produces marked increases in arterial blood pressure and heart rate. In this study, we evaluated the effects of 10% lidocaine preoperatively sprayed for attenuation of the perioperative hemodynamic response during suspension microlaryngeal surgery. MATERIALS AND METHODS: Fifty American Society of Anesthesiologists (ASA) class 1 patients scheduled for excision of a vocal polyp by suspension laryngoscopy were randomly divided into two groups (n=25 for each group). They were intubated without 10% lidocaine spray (control group) or given 1.5 mg/kg of 10% lidocaine sprayed onto the pharyngolaryngeal and intratracheal sites 90 sec prior to intubation (10% lidocaine group). Anesthesia was maintained using desflurane in O2/N2O 50%. The arterial blood pressure and heart rate were measured at preinduction (T0), 1 min (T1), 3 min (T2), 5 min (T3) after tracheal intubation, and 1 min (T4), 3 min (T5), 5 min (T6) and 10 min (T7) after the suspension laryngoscopy. RESULTS: In the 10% lidocaine group, the arterial blood pressure and heart rate at 1 (T1), 3 (T2) min after tracheal intubation and 1 (T4), and 3 (T5) min after suspension laryngoscopy were lower than the same measurements in the control group. CONCLUSION: 10% lidocaine sprayed onto the pharyngolaryngeal and intratracheal sites before intubation was an effective method for attenuation of the perioperative hemodynamic response during suspension microlaryngeal surgery.