[Beta-adrenergic mediation of the central control of respiration: myth or reality]

Self poisoning with beta-blocking drugs might increase with the extension of their therapeutic fields. Usually the management of this intoxication is mainly directed toward antagonizing the beta-adrenoreceptor blocking effects. Thus attention is specially directed to the cardiovascular condition and to the bronchoconstrictor effect. Nonetheless, in spite of this treatment, fatal cases have been reported, suggesting that other complications are responsible of the clinical course of this acute poisoning. In fact, in some cases, a respiratory arrest appeared as the major determinant of death, although the cardiovascular effects were correctly antagonized. Furthermore, the few studies in animals and in healthy volunteers indicated that beta-adrenergic mechanisms in the brain stem stimulate the ventilatory control system. Beta 1 lipophilic antagonists induce a central ventilatory depression and consecutively a respiratory arrest, which is not antagonized by beta mimetic drugs. Awareness of this complication may lead to a greater care in managing the poisoned patients and in starting early mechanical ventilation, which influence the outcome favourably.