[Sympatho-adrenergic reactions following theophylline administration with the use of various anesthesia technics]

The mechanism of action of theophylline is still the subject of controversy. Possible mechanisms that have been suggested are inhibition of phosphodiesterase, release of catecholamines, effects on intracellular calcium, and adenosine antagonism. With regard to these aspects, it was the aim of this study to compare sympatho-adrenal responses after theophylline application during different anesthetic techniques. A total of 60 patients scheduled for orthopedic surgery were investigated: they were divided into three groups of 20 patients who received either halothane anesthesia with thiopentone induction, modified neurolept anesthesia with fentanyl and midazolam, or spinal anesthesia with bupivacaine and mepivacaine. Within these three groups, the patients were randomly allocated to a theophylline collective receiving an injection of theophylline, 4 mg/kg body weight and to the control group. Plasma levels of epinephrine and norepinephrine (by HPLC/ECD), glucose, lactate and free glycerol and MAP and HR were determined over a period of 120 min. In all groups, epinephrine levels increased immediately after injection of theophylline; group levels of epinephrine were higher in the theophylline-groups than in controls (P less than 0.0001). A remarkable increase was observed within 60 min. Peak epinephrine concentrations were comparable after single injections of 100 micrograms or infusions of 5 micrograms/min. The norepinephrine increase after theophylline injection was brief and less pronounced. MAP, HR, glucose, lactate and free glycerol were not influenced by theophylline. A comparison of the theophylline patients showed no statistical differences attributable to the different anesthetic techniques.(ABSTRACT TRUNCATED AT 250 WORDS)