Initial Pain Management Research Articles

SOMATIC VERSUS SYMPATHETIC MEDIATED CHRONIC LIMB PAIN

It has been helpful in our practice to separate somatic from sympathetic-mediated peripheral nerve pain. We would recommend application of the new nomenclature of type I complex regional pain (sympathetic dystrophy) and type II complex regional pain (causalgia) (see Table 1). We believe it is essential that both of these conditions be separated into their early and late phases and that the treatment alternatives be customized for the individual patient and the peripheral nerve involved. If a cast, pin, or external fixation apparatus is associated with peripheral nerve pain, the offending apparatus must be removed immediately and other forms of treatment initiated for the underlying injury. For acute injury and postsurgical pain, narcotic pain medications should be used no longer than 72 hours and careful patient re-examination must be performed if pain persists. Prescription of narcotic pain medications on a continuing basis is often the primary reason for the development of chronic pain syndromes. Physical therapy for the patient with chronic peripheral limb pain must be performed in a pain-free environment. "No pain, no gain" does not apply in the treatment of chronic limb pain-rather the reverse: "Only gain with no pain." In differentiating between sympathetic pain and somatic pain, the use of the reflex sympathetic dystrophy (RSD) score can be helpful (Table 4). If the pain is somatic, treatment options include: Somatic Pain: Treatment Isolated nerve block Continuous nerve block TENS (external) Direct electrical nerve stimulation (internal) Nerve ablation If the pain is sympathetic in origin, treatments to be considered are: Sympathetic Nerve Pain: Treatment Protection of limb (garment or splint) Combine with active use Sympathetic blocks single continuous Sympathectomy In addition, the treatment of each of those conditions must be directed at the primary condition. Once the two conditions are separated, a careful program of pain management is required. In patients who present with late pain dysfunction, the more commonly observed phenomenon at our institution, the combination of physician, surgeon, and anesthesiologist is essential. The role of physical therapist in restoring function to the injured limb must be discussed and planned carefully. Initial pain management is organized through a qualified anesthesiologist dedicated to this field. Physical therapy follows but only in a pain-free environment. The surgeon's role is to assist and direct the pain management program. Surgeons can be involved in the placement of percutaneous catheters, as well as isolated peripheral nerve blocks. Surgical intervention is limited to the release of compressive neuropathies, nerve transfers, and revascularization of the peripheral nerve bed. The surgeon occasionally may be involved in the manipulation and pinning of contracted joints, as well as release of muscle or joint contractures, followed by a supervised program of early range of motion. Finally, it is important that both physician and surgeon serve as patient advocates when questions of workers' compensation intervene that could deter proper treatment programs or when the patient needs the encouragement and guidance to continue with treatments that don't always initially appear to have immediate results. Finally, requests to the surgeon to find an operative cure must be resisted while continued psychological encouragement is provided.

COMPARTMENT SYNDROME IN TIBIAL SHAFT FRACTURE MISSED BECAUSE OF A LOCAL NERVE BLOCK

Compartment syndrome is a serious complication of fractures of the tibial shaft and its clinical presentation and evaluation have been well documented (Holden 1975; Kikuchi, Hasue and Watanabe 1978). The most important diagnostic feature is the presence of inappropriate pain even after stabilisation of the fracture by a cast or by external or internal fixation. Pain is made worse by passive stretching of the muscles involved and there is an associated sensory disturbance. The prognosis is directly related to the speed at which the diagnosis is made and treatment begun. It has been shown that muscle can tolerate only four hours of ischaemia without injury (Heppenstall et al 1988; Heckman et al 1993). We describe a patient with a fracture of the tibial shaft in whom the diagnosis of compartment syndrome was delayed because of the use of a local nerve block given in the operating theatre after intramedullary nailing. Case report. A 28-year-old man presented after a football injury with a closed fracture of the tibial shaft (42-A2.2 according to the AO classification (Muller et al 1990)). Before operation there were no signs of neurovascular compromise or of a compartment syndrome. The fracture was initially stabilised in a plaster back slab and closed, unreamed locked intramedullary nailing then performed. At the end of the operation, the patient was given a triple nerve block (femoral, obturator, lateral cutaneous nerve of thigh) using bupivacaine 0.5% for pain control. After operation, he was entirely free from pain, although he did complain of areas of altered sensation in his foot and leg, but these varied in site and were initially thought to be a result of the nerve block rather than a symptom of a developing compartment syndrome. Pressure measurements were made 48 hours after operation because symptoms persisted and there was inability actively to extend the big toe. They showed a pressure of 108 mmHg in the anterior compartment. We performed fasciotomy urgently but all the muscles in the anterior compartment were dead. No other compartment was involved. The whole of the anterior tibial compartment was debrided 48 hours later as there was no sign of recovery. The patient now walks with an orthosis. Discussion. The treatment of postoperative pain in patients whose tibial fractures have been stabilised is usually by elevation of the injured leg and the use of oral or intramuscular analgesics, especially non-steroidal anti-inflammatory agents. Local anaesthetic nerve blocks are now also commonly given to patients with fractures of the lower limb; they are effective and especially useful after fracture of the femoral shaft. A nerve block using bupivacaine persists for about eight hours (Macrae and Davies 1993), but recovery from the block may be patchy and erratic over a period of several hours. The diagnosis of compartment syndrome is essentially

Pain management in the opioid-addicted patient with cancer

Two patients with an active or recent history of opioid abuse had painful complications of cancer that required narcotic analgesic therapy. Initial pain management was difficult due to issues of distinguishing tolerance from disease progression, concurrent methadone maintenance, and drug-seeking behavioral patterns. Pain control was achieved with psychological support, medication contracts, and attention to proper dosing of opioids. Suggested guidelines for management of these cases are offered.