J.L. Madrid

Intraventricular morphine for intractable cancer pain: rationale, methods, clinical results

The experience with the administration of intraventricular morphine for the control of malignant pain in 197 patients is analyzed. Small doses of morphine injected via a ventricular reservoir provided satisfactory control of otherwise intractable pain in terminal cancer patients. Complete analgesia together with a favourable behavioral response was obtained without noticeable neurological changes or side‐effects annoying or severe enough for the patients to discontinue therapy. Tolerance was much less marked than with parenteral opiates. Chronic intraventricular therapy can be safely performed on an outpatient basis by injecting the opiate once or twice a day. The method may be improved by using refillable continuous‐infusion devices and new drugs able to retain the analgesic effects of morphine while eliminating the unwanted ones.

Intrathecal therapy: rationale, technique, clinical results

In 35 patients a subcutaneously implanted injection port/reservoir was used to provide intrathecal morphine to relieve pain due to cancer. The reservoir offers an alternative to rather expensive devices. It can be used for repeated injections or for infusion. It is easy to locate and facilitates ambulatory treatment. The injections were carried out by members of the patients family after they had been taught how to do it. Initially, doses of 0.25–0.5 mg of morphine resulted in pain relief for 14 to 24 hours. After 5 weeks of treatment morphine requirements increased to 0.75–2 mg. Side‐effects were minimal, and three delayed CSF fistula, two of them confirmed by isotope tracking with Tc99m, closed spontaneoulsy.

Percutaneous compression of the gasserian ganglion for trigeminal neuralgia

The case of a 68 year-old man who developed a fatal intracranial hemorrhagic complication following percutaneous compression of the gasserian ganglion for trigeminal neuralgia is reported. The complication was likely related to improper placement of the Fogarty catheter into the temporal fossa out of the Meckels cave. The anatomical structures at risk of damage by misplaced needle or catheter and some relevant technical details aimed to prevent extratrigeminal complications related with this and other percutaneous trigeminal lesioning procedures are analyzed.

Plasma concentration of beta-endorphin as objetive tracer in the treatment of acute pain

AIM OF INVESTIGATION: To develop an assay using HPLC technique for the extraction of oxycodone from human plasma and its subsequent quantification. METHOD: The plasma concentrations of oxycodone have been determined after oral, rectal anmavenous methods of administration using the assay which has proved efficient in providing a high yield of oxycodone and clean chromatographs. RESULTS: Preliminary studies have demonstrated the expected variability in the plasma concentrations with oral and rectal routes of administration. Of importance, the time taken to reach maximum plasma concentration after oral administration is 1 hr and after rectal administration 3 hrs. The duration of sustained plasma concentration after rectal administration has been shown to be longer than expected. With the intravenous route, plasma levels are sustained after an initial fall. CONCLUSION: With the completion of the study, the pharmacokinetics of oxycodone will be better understood. More effective dosing schedules may be possible to maximise pain relief with oxycodone, a thebaine derivative which has been used clinically since 1917 for relief of moderate to severe pain associated with cancer.

Ambulatory intrathecal morphine in chronic malignant pain with an implantable reservoir

SUBARACHNOID ADMINISTRATION OF BUTORPHANOL FOR THE RELIEF OF POST-OPERATIVE PAIN. K.Z. Kodeirat I.A.-G. Ramadan*and S.E.-E. Shaheen,* (SPON: M.E. El-Sawy), Dept. of Anesthesiology, Al Hussien University Hospital, Cairo, Egypt Aim of Investigation: The present study was undertaken to evaluate the analgesic efficacy and safety of subarachnoid administration of butorphanol tartrate, a potent agonist antagonist narcotic analgesic, along side with bupivacaine for spinal anaesthesia. Methods: Two groups of patients undergoing transurethral prostate resminto which the first group received subarachnoid injection of 15 mg. bupivacaine as 3 ml. of 0.5% concentration in 10% dextrose solution, while the other group received the same above dose to which was added 0.4 mg. butorphanol. Results: There were no significant differences between the two groups as regarding age, cardiovascular or respiratory pathology, mental status and ASA grade. Also, there was no significant sensory block or the duration of block between the two groups. Only 9% of butorphanol group necessitated the administration of analgesic drugs post-operatively, while 36% of the other group needed the same requirements. Conclusion: The use of butorphanol along side with bupivacaine in subarachnoid anaesthesia reduces the need of post-operative analgesia, compared to the use of bupivacaine anaesthesia alone.

Poster cord electric stimulation in lower limb ischemia

Aim of investigation: To evaluate the analgesic and vasodilator effect of posterior cord electric stimulation in patients with lower limb ischemia refused for surgery. Methods: 12 patients have been studied in a prospective way, all of these included in trades III and IV of the Fontaines scale ( Dain at rest and trophic lesions respectively 1. The majority of the cases had been submitted previously to lumbar sympathectomy o revascularitation surgery. It had been used unipolar electrode model 3483s of Medtronic inserted by percutaneous punction, the electric stimulator was set pw: 0.05 msec, v: 1 volt, rate: 100 pps and amplitude according with the patient response. The evaluation of the results was made according to clinical response, sympathetic function probes and infrared teletermography, before and 7, 14 and 30 days after implantating the electrode. Results: It has been appreciated analgesia and subjective improvement in all patients, the sympathetic function probes and infrared teletermography showed us objective improvement of peripheral circulation, in some &se; the trophies lesions of the patients with chronic ischemia grade IV reverted. Conclusions: The posterior cord electric stimulation may be an analgesic method for the patients with lower limb ischemia also improves the peripheral circulation. The effect on the circulation may save a limb codemned to amputation or at least postpone it.