Neuronal blockade with morphine.

Abstract

Summary A patient with an apical lung tumour invading the brachial plexus (Pancoast's tumour) suffered from unbearable pain unmodified by daily treatment with morphine 180 mg subcutaneously. An interscalene brachial plexus block was performed using a solution containing 5 mg morphine hydrochloride in 10 ml isotonic saline. Complete analgesia was obtained after 20 minutes, an effect which lasted for the next 36 hours. Neuro‐axonal transport of morphine to the spinal cord may be the explanation of the effect, an hypothesis which ought to be subjected to controlled trials.

Does the addition of morphine to brachial plexus block improve analgesia after shoulder surgery?

“…In the case of opioids it would then become possible to induce analgesia via the mu, kappa and delta receptors found in the dorsal horn of the spinal cord. This theory has been invoked to explain how analgesia lasting 36 h was reported after interscalene injection of morphine 5 mg for a patient suffering from chronic pain [20]. However, Dahl and colleagues [14], who compared the effect of morphine injected extradurally with that injected perifemorally, concluded that if centripetal axonal transport existed it was not clinically significant.…”