[Post-spinal anesthesia headache--some other physiopathological mechanism?].

The authors carried out a study on patients in whom spinal anaesthesia was performed for various surgical procedures. In a first group of patients neither ephedrine nor other sympathicomimetic drugs were administered before spinal anaesthesia, while in the second group ephedrine was given on a systematic basis as premedication, with the exception of patients who had an absolute contraindication for this drug. In the first group headache following spinal anaesthesia was much more frequent and it was inferred that hypotension with consecutive hypoxia could be considered as a pathophysiological mechanism of headache, beside the already known and accepted mechanisms.