The dangerously high levels of plasma potassium known to follow succinylcholine chloride administration in patients with burns or trauma have also been noted in patients with paraplegia or hemiplegia, muscular dystrophy, and multiple sclerosis. Of 40 patients with these neuromuscular diseases, 15 had increases in potassium levels between 1 and 6 mEq/liter after receiving succinylcholine chloride, 1 mg/kg of body weight. Most increases over 1 mEq/liter occurred in those patients who had been ill for less than six months or, if longer, who had disease of a progressive nature. The degree and extent of muscle paralysis seemed directly correlated with relaxant-induced hyperkalemia.

Succinylcholine-Induced Hyperkalemia in Neuromuscular Disease

THIS all began during the World Congress of Anaesthesiologists in Holland in June 1992, at an extramural multinational panel convened to prepare an educational videotape.† Speakers from the United States and Germany described pediatric cases of sudden rhabdomyolysis and hyperkalemic cardiac arrest after administration of succinylcholine. Despite prompt and apparently skilled resuscitation, the mortality rate was 40–55%. This surprising and puzzling mortality rate prompted considerable discussion and, over time, repeated reflection on what might be happening.

Cardiac arrest after succinylcholine: mortality greater with rhabdomyolysis than receptor upregulation.

Increasing numbers of patients with spinal cord injury present for surgery or obstetric care. Spinal cord injury causes unique pathophysiological changes. The most important peri-operative dangers are autonomic dysreflexia, bradycardia, hypotension, respiratory inadequacy and muscle spasms. Autonomic dysreflexia is suggested by headache, sweating, bradycardia and severe hypertension and may be precipitated by surgery, especially bladder distension. Patients with low, complete lesions, undergoing surgery below the level of injury, may safely do so without anaesthesia provided there is no history of autonomic dysreflexia or troublesome spasms. An anaesthetist should be present to monitor the patient in this situation. General anaesthesia of sufficient depth is effective at controlling spasms and autonomic dysreflexia but hypotension and respiratory dysfunction are risks. There is a growing consensus that spinal anaesthesia is safe, effective and technically simple to perform in this group of patients. We present a survey of 515 consecutive anaesthetics in cord-injured patients and a review of the current literature on anaesthesia for patients with chronic spinal cord lesions.

/pdf/anaesthesia-for-chronic-spinal-cord-lesions-1bgno6ylzo.pdf

Anaesthesia for chronic spinal cord lesions

Traumatic spinal cord injury is frequently associated with brain injury and with alterations in respiratory and cardiovascular function that require critical care management. Complications include respiratory failure, atelectasis, pneumonia, neurogenic shock, autonomic dysreflexia, venous thromboembolism, and sepsis. While complications may be managed with supportive care, the goal of ameliorating neurologic outcome has proved elusive. Methylprednisolone, when instituted <8 hours after traumatic spinal cord injury, was associated in two clinical trials with statistically significant improvements in motor scores at 6 months and 1 year; however, critical reappraisal of these data raises questions about their validity and clinical relevance. Until more evidence of clinically effective therapies is available, acute management must be driven by pathophysiologic principles, with emphasis on interventions that attenuate secondary neurologic injury; these include the rational use of immobilization, cautious airway management, and promotion of cord perfusion and oxygenation with the appropriate level of hemodynamic and respiratory support. Clinical trials of pharmacologic neuroprotection have yielded disappointing results, but the ongoing elucidation of spinal cord repair and regenerative mechanisms suggests new therapeutic prospects.

Critical care and perioperative management in traumatic spinal cord injury.

Severe life-threatening hyperkalaemia may occur following administration of suxamethonium during certain periods after burns, neurological injuries, and in certain other conditions. Although this response is well-known, there is disagreement about when it may occur. This review describes the normal hyperkalaemic response to suxamethonium, the factors affecting it, the conditions in which it may be exaggerated, and the periods of high risk.

William Hambelberg

Papers

Succinylcholine--danger in the spinal-cord-injured patient