Clinical applications of functional electrical stimulation.

Functional Electrical Stimulation (FES) allows the restoration of controlled muscle contractions, and hence limb function via computer control, in patients with irrecoverable upper motor neuron lesions. Wide experience has been recorded in spinal cord injured paraplegics and tetraplegics and to a lesser extent in cerebrovascular accident victims. The electrodes, either surface or implanted, stimulate muscles electrically through a stimulator activated by a control source which is in turn activated by the remaining functions of the user. Future advances in electrode technology and control and command sources activation systems as well as development of "close-loop" systems need to be made if wide patient acceptance of this modality is to be ensured.

Contractile characteristics on electrical stimulation of muscle with multiple motor points. An in vivo study in rabbits.

The purpose of this study was to investigate the significance of motor points in muscle and to determine their role in functional electrical stimulation. The long head of the triceps in adult female rabbits was used as the muscle model to study the contractile response to electrical stimulation of 1 motor point as opposed to simultaneous stimulation of multiple motor points in the muscle belly. The contractile response was studied with gradually increasing voltage amplitude and with or without added loads. Simultaneous stimulation of multiple motor points gave a consistently greater range of elbow extension when compared with stimulation of individual motor points. At low-voltage values, simultaneous stimulation of multiple motor points gave excursions obtainable only with high voltages on a single motor point. This pattern was observed with and without loads. These findings indicate that for optimal control of muscle contraction in functional electrical stimulation, electrodes may need to be inserted into multiple motor points for a given muscle. Stimulation for maximal muscle function then may be possible in the optimal low-voltage range without relying on spillover effect of high voltages. Nerve, muscle, and electrode damage also may be avoided.

Single-blind comparative analgesic and safety study of single doses of intramuscularly administered ketorolac tromethamine and pethidine hydrochloride in patients with pain following orthopaedic surgery.

Ketorolac tromethamine, a potent non-narcotic prostaglandin synthetase inhibiting analgesic was compared with pethidine for relief of moderate to severe postoperative pain. Forty-eight patients received Ketorolac 0.5 mg/kg and 52 received pethidine 1.25 mg/kg. The degree of pain prior to the administration of the drug and pain relief that followed were quantified using a vertical visual analogue scale (VAS) and monitored at hourly intervals. The safety profile was also studied by recording all adverse events noted. The mean pain (VAS) score at medication for Ketorolac was 7.04 and for pethidine 7.09. The pain relief obtained in the first four hours following administration of the drugs was similar for pethidine and Ketorolac. Although Ketorolac showed a longer sustained pain relief, time to peak analgesia after administration of this drug was slower than that after pethidine. It took 30 to 50 min for pethidine compared to 75 to 150 min for Ketorolac to achieve peak analgesia. The latter is therefore inappropriate if rapid pain relief is required. The incidence of side effects was significantly greater with pethidine (40.4%) as compared to Ketorolac (10.4%). The similar analgesic efficacy to pethidine makes Ketorolac an appropriate drug for the relief of postoperative pain especially in day surgery settings where observation following administration of the drug as in the case of pethidine can be dispensed with and patients sent home earlier because of the minimal side effects associated with its use. Caution must be exercised with the use of large doses of Ketorolac especially if the drug is used for more than 5 days to avoid serious complications like renal failure and gastrointestinal bleeding.