Cardiovascular responses to intraosseous injections containing catecholamines.

The cardiovascular responses to Adrenaline and Noradrenalin, given intraosseously, are reported. Intraosseous injections of anesthetic containing catecholamines clearly demonstrate the rapidity with which the catecholamines are absorbed into the general circulation. Adrenalin-containing local anesthetic gave rise to rapid increases in the heart rate and blood pressure within a few seconds of the injection. Such cardiovascular responses, in many instances, were unacceptable to the subject because of the tachycardia and a feeling of intense tightness across the thorax. With Noradrenalin, on the other hand, the cardiovascular responses were asymptomatic, although it was usual for the heart rate to fall while the peripheral resistance and the blood pressure increased. Direct comparison was made, in the same persons, of infiltration and intraosseous injection of a Noradrenalin-containing local anesthetic. Insignificant responses were found with infiltration injections of catecholamines (0.9 ml. of 1/80,000 solutions) which is in agreement with previously published data. However, similar solutions injected intraosseously elicited cardiovascular responses. Although intraosseous injection of lidocaine hydrochloride containing 1/80,000 Noradrenalin appears clinically acceptable, a further search for anesthetics without effects on the cardiovascular system is desirable.