The clinical importance of hyperkalaemia following suxamethonium administration

Perioperative Pharmacologic Management of Patients with End Stage Renal Disease

The pharmacokinetics of numerous medications used in the perioperative period are altered in patients with end-stage renal disease. Clearance of drugs, or their metabolites, that are normally excreted by the kidney is markedly reduced in ESRD. In addition, patients with ESRD may also have alterations in gastrointestinal absorption, volume of distribution, protein binding, and metabolic clearance of pharmacologic agents. Finally, drug removal may be augmented during dialysis. All of these factors contribute to the need for dose adjustment of medications, including analgesics, anesthetics, neuromuscular blockers, and antimicrobial agents, which may be used in the perioperative management of the ESRD patient.

Advances in transplantation 1940-2014

The history of medicine is that what was inconceivable yesterday and barely achievable today often becomes routine tomorrow. Liver transplantation began with almost no resources at the same time as the tentative first steps were taken to land a man on the moon. Because human lives would be at stake, both objectives had a sacramental element from the outset: a solemnly binding commitment to perfection. The gift of an organ is really a gift of life, and something as valuable as a life-saving organ is more important to a suffering patient than wealth or power. The concept of a team approach to the care of the transplant patient is an important factor in the development of a successful program. This has resulted in recipient survival rates reaching 90% at one year.

Tetanus in developing countries: a case series and review

PURPOSE

Few anesthesiologists have expertise in the diagnosis and treatment of tetanus, a disease that remains prevalent in developing countries. We report on a series of four cases of tetanus cases recently encountered in Rwanda. We review the clinical epidemiology, pathophysiology, diagnosis and the treatment of tetanus, and provide implications for anesthesiologists and critical care physicians.

CLINICAL FEATURES

We report four cases, two involving adults who were inadequately vaccinated and experienced injuries, and two involving neonates, both of whom underwent umbilical cord transection using unsterilized equipment. All patients required tracheal intubation, and were mechanically ventilated when equipment was available. One adult and one neonate succumbed to the disease. These cases highlight the difficulties of diagnosis and management of complicated diseases in the resource-challenged health care setting of developing countries.

CONCLUSIONS

The differential diagnosis of tetanus may be confusing, and survival depends on the rapidity of treatment with antitoxin, as well as adequate supportive care. High doses of sedatives and muscle relaxants, as well as prolonged mechanical ventilation, are usually necessary. Mortality remains high, usually resulting from late respiratory failure and cardiovascular collapse, associated with autonomic instability. Anesthesiologists and critical care physicians have an important role to play in the management of these patients. Increased involvement in humanitarian health organizations, immigration from developing countries, and emergence of high risk groups in developed countries will likely result in more exposure of anesthesiologists to the complexities of this disease.

Can succinylcholine be used safely in hyperkalemic patients?

The use of succinylcholine in hyperkalemic patients (serum potassium >5.5 mEq/L) is often viewed as relatively contraindicated, although there are no systematic data to define what preoperative potassium level is safe. We retrospectively reviewed more than 40,000 general anesthetics administered over 70 mo in which succinylcholine was given at the induction. This search yielded 38 patients with a preoperative potassium of 5.6 mEq/L or greater. Survival of the anesthetic was 100%, and no dysrhythmias or other major morbidity were documented upon manual review of the intraoperative automated record keeper charts or the patient medical records. These data allow a 95% confidence interval assessment of maximal risk for an event of 7.9%, which is not negligible, but which almost certainly grossly overestimates the risk for patients with moderately increased potassium levels. A prospective trial to definitively assess the safety margin for succinylcholine use in hyperkalemic patients would be difficult. Therefore, these data, taken in the context of a compelling case for rapid intubating conditions without long-term paralysis, suggest safety in succinylcholine use in patients with modest hyperkalemia.

IMPLICATIONS

In a review of more than 40,000 general anesthetics in which succinylcholine was given at induction, 38 patients had a preoperative potassium of 5.6 mEq/L or greater. All patients survived the anesthetic with no dysrhythmias or other major morbidity documented. Succinylcholine may be appropriate and safe for use in certain patients with moderate hyperkalemia.

Tetanus in the emergency department: A current review

Despite the availability of effective immunization to prevent tetanus, there are still up to one million cases per year worldwide. Although the majority of tetanus cases occur in third world countries, there are still significant numbers of cases occurring in countries such as the United States, where preventive immunization is easily accessible. The Emergency Physician has the opportunity to contribute to the decline of the incidence of tetanus through knowledge of those at greatest risk for inadequate immunization and through providing proper wound care and immunization prophylaxis.

Muscle relaxants in renal disease

The use of neuromuscular blocking drugs during anaesthesia for patients with chronic renal failure is discussed. The disadvantages of the older non-depolarizing agents, such as tubocurarine, alcuronium, and pancuronium are outlined, as are the significant benefits of the use of atracurium or vecuronium in these patients. Preliminary reports on the new non-depolarizing drugs, pipecuronium, mivacurium, doxacurium, and rocuronium are also noted.

Adverse effects of depolarising neuromuscular blocking agents. Incidence, prevention and management

Muscle relaxants block neuromuscular transmission, acting at nicotinic acetylcholine receptors of the neuromuscular junction. Suxamethonium (succinylcholine) is a depolarising agent, whereas all other relaxants in clinical use are nondepolarising. The desired neuromuscular block results from the structural similarity of muscle relaxants to acetylcholine, enabling the interaction with receptors at the neuromuscular junction. Adverse effects of suxamethonium are generally related to its agonist mode of action. Autonomic cardiovascular effects may result. Other adverse effects include anaphylactic or anaphylactoid reactions, and histamine release. Various disease states may present specific considerations in the use of muscle relaxants. Although many complications of muscle relaxants (such as prolonged block or resistance) are easily treated, others may require immediate intervention and vigorous therapy. Careful selection of appropriate relaxants for particular patients will usually prevent the occurrence of complications.

Serum potassium and sodium levels following intravenous suxamethonium in pediatric dental anesthesia

The effects of rectally administered midazolam (.35 mg/kg), diazepam (.70 mg/kg), and placebo used as preanesthetic medications on serum levels of potassium after intravenous suxamethonium in children undergoing dental extractions under halothane anesthesia were examined. Ninety patients between the ages of 2 and 7 years were randomly allocated into three groups in this double-blind parallel study. Blood samples were taken immediately after induction with halothane (Pre-S) and at 1, 3, 5, 10, and 15 minutes after administration of suxamethonium (Post-S). Serum from these samples was analyzed in duplicate for potassium and sodium and the data analyzed statistically. The results showed that mean serum potassium levels tended to remain higher in the two groups that had received a benzodiazepine than in the controls at 5, 10, and 15 minutes Post-S. Although the increases in plasma potassium differed significantly from Pre-S at the various times within each patient group, no significant intergroup differences could be shown except at the 15 minute Post-S stage, when the mean serum potassium level of the placebo group was significantly closer to its Pre-S value than that of the diazepam group. At all stages Post-S the mean serum sodium levels for each of the three groups showed statistically significant decreases from their Pre-S values. However, no statistically significant intergroup differences could be shown.

Emergencies in continuous dialysis patients: diagnosis and management

The number of patients undergoing long-term hemodialysis and peritoneal dialysis is growing in the United States. To provide adequate emergent care to these patients emergency physicians must understand the alterations in normal physiologies present in these patients and how this may affect care. Cardiovascular disease and infection (especially Staphylococcus aureus sepsis) are the leading causes of death among dialysis patients. These patients are also subject to a significantly higher incidence of life-threatening electrolyte disturbances, particularly hyperkalemia and hypercalcemia, than the general population. Suicide, cardiac tamponade, intracranial hemorrhage, bleeding disorders, and bowel infarction are also much more frequent. The inability of dialysis patients to excrete drugs, metabolites, toxins, and fluids significantly alters their responses to common emergencies and should directly influence their care. Failure to recognize these differences in physiology may result in the use of standard forms of emergency therapy that may compound, rather than treat, the underlying disorder. Although most dialysis patients who come into an emergency department have conditions that can, and should, be managed by their nephrologist, the presence of a life threatening emergency requires prompt, appropriate therapy by the emergency physician.

Suxamethonium and hyperkalaemia

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.

Neuromuscular blockade in the emergency department

This article presents a comprehensive review of neuromuscular blocking agents and their uses in the emergency department. These medicines are divided into two categories: depolarizing relaxants (including succinylcholine and decamethonium) and nondepolarizing relaxants (including d-tubocurarine, pancuronium, atracurium, and vecuronium). Also reviewed are pharmaco-kinetics, toxicity, and principal applications of these important agents.

Surgery in the patient with acute or chronic renal failure

Medical management of the surgical patient with renal dysfunction revolves primarily around the application of sound medical principles used in the care of all patients. In this article, the unique peculiarities associated with renal failure are stressed. Knowledge of these points is vital in securing a favorable outcome for the patient.

Suxamethonium-induced hyperkalaemia following cold injury

Within the space of 9 days, a 4-month-old baby requiring cardiac surgery was exposed to two periods of hypothermic circulatory arrest for surgery, and prolonged surface cooling postoperatively. At the end of this period, the administration of suxamethonium was associated with a marked rise in serum potassium.

Serum potassium following succinylcholine in patients with brain tumours

Serum potassium levels were measured in 15 patients with brain tumours between 3-7 cm diameter, during thiopentone/70 per cent N2O in O2 anaesthesia, with mask ventilation controlled to maintain a constant end-tidal CO2 concentration. Potassium levels were determined one minute before and one and ten minutes after administration of succinylcholine 1.0 mg X kg-1 IV. No statistically significant increase in serum potassium occurred following succinylcholine, nor were there any ECG changes associated with succinylcholine administration. Use of succinylcholine in patients with brain tumours does not appear to cause elevation of serum potassium levels or ECG changes.

Vecuronium in patients with and without renal failure

Fifteen patients with and ten patients without renal failure (RF) were given vecuronium as the sole muscle relaxant during anaesthesia. RF patients were divided into two subgroups according to the daily diuresis (RF I, below 0.5 l/d; RF II, over 0.5 l/d). Vecuronium was given in small doses until the electromyographic twitch response showed 90% relaxation. The results showed great individual variations, and there were no statistically significant differences between the study groups in the parameters studied (ED90 dose, total consumption of the drug in mg kg-1 min-1, vecuronium plasma concentrations, twitch response) during induction and anaesthesia. After reversal of relaxation, the twitch response recovered more slowly in the RF I group than in the others (P less than 0.05). No complications occurred and it is confirmed that it is safe to use vecuronium as a muscle relaxant in patients with RF.

[Prevention of hyperkalemia and muscular fasciculations induced by suxamethonium]

Suxamethonium has not yet been replaced to ease endotracheal intubation despite its many undesirable side effects. Hyperkalemia and muscle pain are two such side effects; they are not reliably prevented by giving, before suxamethonium, a small dose of a non depolarizing muscle relaxant, although it does decrease muscle fasciculations. The purpose of this study was to compare with a control group three different pretreatments of these undesirable effects of suxamethonium: 1) hyperventilation, 2) calcium chloride which are accepted means of lowering the serum potassium, and 3) magnesium sulfate which has been reported in a non-controlled study to decrease muscle fasciculations. The study was performed in 40 patients (10 per group) in whom changes of plasma potassium and calcium levels were determined and muscle fasciculations measured by an objective method. Serum electrolyte variations and the quantity and duration of muscle fasciculations were similar in all groups. None of the pretreatments administered had any adverse effect on the neuromuscular block induced by suxamethonium.

Anaesthesia for the patient with impaired renal function

Patients with renal disease are at risk of further deterioration of renal function and acute tubular necrosis when subjected to anaesthesia and surgery. Optimal fluid loading and careful selection of anaesthetic techniques and agents, appropriate monitoring and the use of mannitol and dopamine assist in the maintenance of renal blood flow and help preserve renal function in these patients. In association with renal failure, physiological changes in other systems result in reduced oxygen supply to the tissues, metabolic disturbances, impairment of the coagulation and immune defence mechanisms and an increased risk of cardiac and cerebrovascular catastrophe. Although many anaesthetic techniques including regional analgesia may be used successfully in these patients caution with most drugs, especially pethidine, phenoperidine, suxamethonium and all non-depolarising neuromuscular relaxants is recommended. Of the volatile anaesthetics currently available, halothane is the agent of choice. Oxygen therapy and close monitoring of cardiorespiratory function are necessary postoperatively.

Lignocaine pretreatment for suxamethonium. A clinicobiochemical study

Lignocaine pretreatment (2 mg/kg) significantly restricted the increase in serum potassium and decrease in serum calcium caused by suxamethonium. Suxamethonium muscle pains occurred in only 8% of patients who received lignocaine just before induction of anaesthesia. The incidence of muscle pains was 45% in those patients who were not given lignocaine.

Increased activation effects of succinylcholine in neurological patients

Succinylcholine, a depolarizing muscle relaxant with both activating and desensitizing effects, is used to facilitate endotracheal intubation. The activating effects were found to be above-normal on induction of anesthesia in 7 neurological patients: generalized muscle spasm in 1 myotonic patient, contractures or prolonged contractions in "anatomically" denervated muscles (1 patient), in "functionally" denervated muscles (1 patient) and in "centrally" denervated muscles (4 patients). One of these four presented hyperkalemia and cardiocirculatory collapse. It is important to differentiate these anomalous responses to succinylcholine from those occurring as early signs of rhabdomyolysis or malignant hyperthermia.

Plasma potassium after halothane--suxamethonium induction in children

The changes in plasma potassium following inhalation induction of anaesthesia with halothane followed by suxamethonium were studied in 48 normal children aged 1 to 10 years. Highly significant increases were found in both age groups studied (5 years and under, and 6 to 10 years). The mean percentage increase in plasma potassium and the proportion of children in whom an increase of 0.4 mmol/litre or greater was found, were both greater than in an earlier study on children after thiopentone induction and suxamethonium.

The influence of fazadinium on the potassium efflux produced by succinylcholine

Succinylcholine-induced potassium efflux was studied in two groups of healthy adult patients presenting for elective surgery. One group (Group 1) of 12 patients received alfathesin induction followed by succinylcholine. The other group (Group 2) of 12 patients were pre-treated with fazadinium 0.075 mg . kg-1 about three minutes before administration of alfathesin and succinylcholine. Serial blood samples were taken pre-induction, post-induction and after succinylcholine for estimation of plasma potassium. The results show that pre-treatment with fazadinium 0.075 mg . kg-1 was effective in preventing succinylcholine-induced potassium efflux.

Relation of precurarization to suxamethonium to provide ease of intubation and to prevent post-suxamethonium muscle pains

Tubocurarine 0.05 and 0.07 mg.kg-1, gallamine 0.1 and 0.2 mg.kg-1 and pancuronium 0.01 and 0.02 mg.kg-1 given three minutes before suxamethonium 1.0, 1.5 and 2 mg.kg-1 in groups of 10 patients each (total 210 patients) to compare ease of tracheal intubation and incidence of post-suxamethonium muscle pain. These were compared with a control group of suxamethonium 1.0, 1.5 and 2 mg.kg-1 given alone after thiopentone 5 mg.kg-1. On analysis, tubocurarine 0.07 mg.kg-1 and suxamethonium 2 mg.kg-1 was the ideal combination with the best intubation conditions and the lowest incidence of post-suxamethonium muscle pains. The second best combination was gallamine 0.2 mg.kg-1 and suxamethonium 2 mg.kg-1. Pancuronium 0.01 mg.kg-1 and 0.02 mg.kg-1 in combination with suxamethonium 2 mg.kg-1 were satisfactory, although less efficient than the combination with either tubocurarine or gallamine.

A case of rhabdomyolysis associated with suxamethonium

A boy presenting for oesophagoscopy developed myoglobinuria during convalescence from the procedure. A susceptibility to malignant hyperpyerexia was considered in the differential diagnosis but was felt to be unlikely on the basis of in vitro testing of muscle biopsy specimens. A review of relevant papers suggests that rhabdomyolysis of significant degree following suxamethonium administration may be more common than generally appreciated, particularly in children.

Prolonged curarisation following renal transplantation. A retrospective study

A retrospective study of postoperative respiratory morbidity in 247 patients requiring renal transplantation between 1955 and 1973 showed that 7 patients required postoperative controlled ventilation for up to 6 days. The nondepolarising relaxants tubocurarine and pancuronium were used in only 65 patients, but all 7 cases of respiratory failure occurred in this group. This suggests that the use of these drugsin anephric patients is potentially hazardous so far as postoperative respiratory insufficiency is concerned.

Head injury, spasticity, suxamethonium and hyperkalaemia

Cardiac arrest due to hyperkalaemia following suxamethonium in a patient with generalized spasticity due to head injury is reported and discussed.

Pancuronium bromide in emergency surgery

Pancuronium bromide, a steroid non-depolarising muscle relaxant has been used to assist intubation before emergency operations in 32 patients and has been found to be satisfactory for quick intubation in a dose of 0-1 mg per kg of body weight. There was no vomiting during induction.

Anaesthetic considerations in chronic renal failure

This paper discusses the anaesthetic problems presented by patients in chronic renal failure. The anaesthetic agents and techniques used in 181 patients who underwent 941 operations (including 218 renal transplants) are described.

The effects of modified electroconvulsive therapy and four induction agent-relaxant regimes on plasma potassium

Changes in plasma potassium following modified electroconvulsive therapy ‘were investigated using four induction agent-relaxant combinations. Small rises were found for three of the four regimes, but only methohexitone-suxamethonium was associated with a rise significantly greater than that in the control group. There was no correlation between the changes in plasma potassium and the degree of modification of the seizure. In no patient was a dangerous level of hyperkalemia found to occur.

Changes in serum potassium after suxamethonium in children

The effect of the administration of intravenous suxamethonium (1 · 5 mg/kg) on serum potassium was measured in 37 children, whose ages ranged from one month to 16 years. In all patients anaesthesia was induced with thiopentone, and maintained with nitrous oxide and oxygen.

Serum potassium concentrations were estimated using venous blood taken immediately after induction and at one, two, three and four minutes after suxamethonium.

No significant changes were found in the groups aged six to 10 years and 11 to 16 years. However, in the group aged five years and less, a small, but significant, mean increase of 0·23 mEq/l was found. Individual children in each group had significant increases in serum potassium, but this phenomenon was less common than has been reported in adults.

Different premedications had no effect on serum potassium, and changes could not be related to the presence or degree of muscular fasciculations.