Epinephrine administration via a laryngeal mask airway: what is the optimal dose?

Background. The aim of this animal study was to clarify the effects of laryngeal mask airway (LMA)-administrated epinephrine and to assess the optimal dose. Methods. Thirty pigs were anesthetized and intubated with a cuffed tracheal tube (TT) and an LMA. Then they were assigned to one of five groups. The control group received distilled water 10 mL via the TT; the TT group received epinephrine 50 g/ kg via the TT; and the other three groups received two, four or six times the TT dose of epinephrine via the LMA. Heart rate (HR) and arterial pressure were monitored before and after drug administration for 15 minutes. Results. After epinephrine administration, the LMA-6 and TT groups had elevated systolic, diastolic and mean arterial pressures at 1 min and there was no significant difference between the two groups. In the TT group, these parameters peaked at 2 min then declined rapidly. In the LMA-6 group, they increased more slowly, and then maintained a plateau. The control, LMA-2 and LMA-4 groups failed to display significant persistent (>2 min) hemodynamic changes. Conclusions. We could not identify an optimal LMA-administrated epinephrine dose. The TT route is suitable when a high peak drug effect is required and the LMA route may be preferable if a persistent plateau effect is desired. Effective LMA administration of drugs may require larger doses than those given via TT. KUO-TAI CHEN ( ) • HUNG-JUNG LIN Emergency Department Chi-Mei Medical Center 901 Chung-Hwa Road, Yung Kang Tainan 710, Taiwan Phone: 886-6-2812811 ext. 57196 Fax: 886-6-2816161 E-mail: [email protected] CHIN-KUN LIAO • NING-PING FOO Department of Emergency Medicine Chi-Mei Medical Center, Liouying HUNG-JUNG LIN Department of Biotechnology, Southern Tainan University of Technology CHIN-CHAN LIN Department of Medical Research Chi-Mei Medical Center HOW-RAN GUO Department of Environmental and Occupational Health and Department of Environmental and Occupational Medicine, Medical College,National Cheng Kung University KUO-TAI CHEN School of Medicine, Taipei Medical University CHIN-KUN LIAO • HUNG-JUNG LIN • NING-PING FOO • CHIN-CHAN LIN • HOW-RAN GUO • KUO-TAI CHEN ORIGINAL SIGNA VITAE 2010; 5(2): 25 28