Citations

Morphine sulfate, a narcotic analgesic, possesses the undesirable side effects of central depression, tolerance, and dependency. Opiate receptors have been found in the brain and the spinal cord. Intrathecally applied opiates produce potent analgesia that can be antagonized by naloxone. The time-response study with tail-flick response after intrathecal injections of a small dosage of morphine (25 μg) demonstrated a long-lasting analgesia. Intrathecal injections of morphine or opiate-like peptides may become a predictable modality of pain relief without attendant loss of other neurologic function.

The current study was conducted to establish a reliable method for the placement of a long (>5 cm) catheter in the axillary neurovascular sheath, and to assess the effect of proximal catheter position on postoperative pain management by continuous bupivacaine infusion. In 20 patients scheduled for upper extremity surgery, a Portex® epidural catheter was advanced a mean distance of 12 cm in the axillary neurovascular sheath and its correct position verified by onset of upper extremity anesthesia and x-ray examination. After operation a continuous infusion of bupivacaine 0.125% was initiated through this catheter. Excellent pain relief (score of 0-1 as evaluated on a visual analogue scale of 0 to 10), and sympathetic blockade was achieved in all patients with an average rate of bupivacaine administration of 7 ml/hr. Additionally administered systemic narcotics were in a mean range of 3-10 mg of morphine/day. Catheters remained in place for an average of 3.7 days. Catheter tips cultured on removal of the catheter (n = 11) yielded negative cultures in eight cases (placement 3.6 ± 0.6 days), and positive cultures in three cases (placement 8.6 ± 2.2 days, mean ± SE). No signs of local or systemic infection were noted in any patient and no specific antibiotic therapy was initiated. This technique is recommended for postoperative analgesia in selected patients. In this study there was a low risk of catheter displacement and no evidence of local anesthetic toxicity. Limiting the duration of continuous axillary catheter infusion to 4 days may minimize the risk of infection.