Midazolam reverses histamine-induced bronchoconstriction in dogs.

نویسندگان

  • K Hirota
  • N Ohtomo
  • Y Hashimoto
  • T Kudo
  • H Ishihara
  • A Matsuki
چکیده

PURPOSE Midazolam has been used clinically as a sedative and as an anaesthetic induction agent. However, the bronchodilating effects of midazolam have not been comprehensively evaluated. We sought to determine relaxant effects of midazolam on the airway. METHODS After our Animal Care Committee approved the study, eight mongrel dogs were anaesthetized with 30 mg.kg-1 pentobarbitone iv, and were paralysed with 200 micrograms.kg-1.hr-1 pancuronium. The trachea was intubated with an endotracheal tube (ID 7 mm) that had a second lumen for insertion of a superfine fibreoptic bronchoscope (OD 2.2 mm) to measure the bronchial cross-sectional area (BCA) continuously. The tip of the bronchoscope was placed at the level of the second or third bronchial bifurcation of the right bronchus. A videoprinter printed the BCA which was then measured with a NIH image program. Bronchoconstriction was produced with histamine (H) 10 micrograms.kg-1 followed by 500 micrograms.kg-1.hr-1. Thirty minutes later, 0 [saline], 0.01, 0.1 and 1.0 mg.kg-1 midazolam and 25 micrograms.kg-1 flumazenil were given. The BCA was assessed before (basal area) and 30 min after the start of H infusion, and was also measured five minutes after each midazolam and flumazenil iv. At the same time, arterial blood was sampled for plasma catecholamine measurement. RESULTS Histamine infusion decreased BCA to 49.7 +/- 17.3% of basal BCA. More than 0.1 mg.kg-1 midazolam increased BCA up to 71.7 +/- 15.3% of the basal (1.0 mg.kg-1) (P < 0.01). Plasma adrenaline concentration was decreased from 6.9 +/- 3.8 to 3.7 +/- 1.9 ng.ml-1 by 1.0 mg.kg-1 midazolam (P < 0.05). Flumazenil did not antagonize the relaxant effect of midazolam but reversed the inhibitory effect of midazolam on histamine-induced adrenaline release. CONCLUSION Midazolam has a spasmolytic effect on constricted airways but this bronchodilatation was not reversed by flumazenil.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Mode of action of halothane on histamine-induced airway constriction in dogs with reactive airways.

To determine if clinical concentrations of halothane have direct relaxant effects on airway smooth muscle, the authors compared dose-response curves to histamine in the control state (thiopental) and during halothane anesthesia (1.0 and 1.5 MAC), in six basenji-greyhound (BG) dogs untreated and pretreated with atropine aerosols (10 mg X ml-1). Pulmonary resistance (RL) and dynamic compliance (C...

متن کامل

In vivo assessment of droperidol-induced bronchial relaxation in dogs using a superfine fibreoptic bronchoscope.

Droperidol has been reported to cause bronchodilatation but its mechanism(s) of action is unknown. We have evaluated the spasmolytic effect of droperidol on histamine- and serotonin (5-HT)-induced bronchoconstriction in dogs. Bronchial cross-sectional area was assessed with a superfine fibreoptic bronchoscope. Twenty-eight mongrel dogs were allocated randomly to one of two groups (histamine and...

متن کامل

I.v. lidocaine worsens histamine-induced bronchoconstriction in dogs.

We have assessed the effect of lidocaine (lignocaine) on histamine-induced bronchoconstriction by direct visualization with a superfine fibreoptic bronchoscope. Seven mongrel dogs were anaesthetized with pentobarbital (pentobarbitone) 30 mg kg-1 followed by 2 mg kg-1 h-1 and pancuronium 200 micrograms kg-1 h-1. The trachea was intubated with a tracheal tube containing a second lumen for inserti...

متن کامل

Mathematical Model to Find the Role of Histamine in Alcohol Induced Bronchoconstriction in Asthmatic Patients

In this paper we try to evaluate the effect of terfenadine, a selective H1-receptor antagonist on alcoholic beverage – induced bronchoconstriction. The size distribution proves that for each inflammatory action the hormone histamine is released in a large number and we conclude that the release of histamine makes a major contribution to alcoholic beverage – induced bronchoconstriction in asthma...

متن کامل

Effects of intravenous and aerosol nifedipine on prostaglandin F2 alpha and histamine-induced bronchoconstriction in anesthetized dogs.

The effect of nifedipine, a calcium slow channel blocking drug, was investigated by varying routes of administration in a canine model of pharmacologically induced bronchoconstriction. Control bronchopulmonary responses, i.e., increases in pulmonary resistance (RL) and decreases in dynamic lung compliance were accomplished by aerosols of prostaglandin F2 alpha and histamine in normal pentobarbi...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Canadian journal of anaesthesia = Journal canadien d'anesthesie

دوره 44 10  شماره 

صفحات  -

تاریخ انتشار 1997