Subcutaneous Terbutaline Use in CKD to Reduce Potassium Concentrations

HYPERKALEMIA IN FOUR ANESTHETIZED RED WOLVES (CANIS RUFUS)

Four clinically healthy red wolves (Canis rufus) developed hyperkalemia during routine anesthetic procedures. All cases were anesthetized using a combination of dexmedetomidine (10-24 mcg/kg), ketamine (2-3 mg/kg), and either midazolam (0.25-0.5 mg/kg) or butorphanol (0.2-0.48 mg/kg). Additional anesthetics were given to effect. Total anesthetic time ranged from 60 to 420 min. Three out of four cases were treated using terbutaline (0.01 mg/kg SC), which successfully resolved the hyperkalemia. No bradyarrhythmias were seen in any cases where electrocardiography (ECG) was monitored (3/4). All cases recovered from anesthesia, with one prolonged recovery. All animals are clinically healthy at the time of writing. Factors including anesthetic duration, the use of α-2 agonists, hyperthermia, and genetics are discussed as possible triggers for hyperkalemia. Serial blood gases, with electrolyte measurements, are recommended during anesthesia of red wolves, particularly when anesthetic time may be prolonged or the patient suffers from hyperthermia. Terbutaline appears to be a successful treatment should hyperkalemia arise.

A novel loss-of-function mutation of the voltage-gated potassium channel Kv10.2 involved in epilepsy and autism

Background

Novel developmental mutations associated with disease are a continuous challenge in medicine. Clinical consequences caused by these mutations include neuron and cognitive alterations that can lead to epilepsy or autism spectrum disorders. Often, it is difficult to identify the physiological defects and the appropriate treatments.

Results

We have isolated and cultured primary cells from the skin of a patient with combined epilepsy and autism syndrome. A mutation in the potassium channel protein Kv10.2 was identified. We have characterised the alteration of the mutant channel and found that it causes loss of function (LOF). Primary cells from the skin displayed a very striking growth defect and increased differentiation. In vitro treatment with various carbonic anhydrase inhibitors with various degrees of specificity for potassium channels, (Brinzolamide, Acetazolamide, Retigabine) restored the activation capacity of the mutated channel. Interestingly, the drugs also recovered in vitro the expansion capacity of the mutated skin cells. Furthermore, treatment with Acetazolamide clearly improved the patient regarding epilepsy and cognitive skills. When the treatment was temporarily halted the syndrome worsened again.

Conclusions

By in vitro studying primary cells from the patient and the activation capacity of the mutated protein, we could first, find a readout for the cellular defects and second, test pharmaceutical treatments that proved to be beneficial. The results show the involvement of a novel LOF mutation of a Potassium channel in autism syndrome with epilepsy and the great potential of in vitro cultures of primary cells in personalised medicine of rare diseases.

Potassium Metabolism and Management in Patients with CKD

Potassium (K), the main cation inside cells, plays roles in maintaining cellular osmolarity and acid-base equilibrium, as well as nerve stimulation transmission, and regulation of cardiac and muscle functions. It has also recently been shown that K has an antihypertensive effect by promoting sodium excretion, while it is also attracting attention as an important component that can suppress hypertension associated with excessive sodium intake. Since most ingested K is excreted through the kidneys, decreased renal function is a major factor in increased serum levels, and target values for its intake according to the degree of renal dysfunction have been established. In older individuals with impaired renal function, not only hyperkalemia but also hypokalemia due to anorexia, K loss by dialysis, and effects of various drugs are likely to develop. Thus, it is necessary to pay attention to K management tailored to individual conditions. Since abnormalities in K metabolism can also cause lethal arrhythmia or sudden cardiac death, it is extremely important to monitor patients with a high risk of hyper- or hypokalemia and attempt to provide early and appropriate intervention.

Evidence in support of hyperkalaemia management strategies: A systematic literature review

BACKGROUND

Hyperkalaemia is a potentially life-threatening condition that can be managed with pharmacological and non-pharmacological approaches. With the recent development of new hyperkalaemia treatments, new information on safe and effective management of hyperkalaemia has emerged.

OBJECTIVES

This systematic literature review (SLR) aimed to identify all relevant comparative and non-comparative clinical data on management of hyperkalaemia in adults. Our secondary aim was to assess the feasibility of quantitatively comparing randomised controlled trial (RCT) data on the novel treatment sodium zirconium cyclosilicate (ZS) and established pharmacological treatments for the non-emergency management of hyperkalaemia, such as the cation-exchangers sodium/calcium polystyrene sulphonate (SPS/CPS).

METHODS

MEDLINE, Embase and the Cochrane Library were searched on 3^rd April 2017, with additional hand-searches of key congresses and previous SLRs. Articles were screened by two independent reviewers. Eligible records reported interventional or observational studies of pharmacological or non-pharmacological management of hyperkalaemia in adults.

RESULTS

Database searches identified 2,073 unique records. Two hundred and one publications were included, reporting 30 RCTs, 29 interventional non-RCTs and 43 observational studies. Interventions investigated in RCTs included ZS (3), SPS/CPS (3), patiromer (4) and combinations of temporising agents (6 RCTs). A robust and meaningful indirect treatment comparison between ZS and long-established cation-binding agents (SPS/CPS) was infeasible because of heterogeneity between studies (including time points and dosing) and small sample size in SPS/CPS studies.

CONCLUSIONS

Despite hyperkalaemia being associated with several chronic diseases, there is a paucity of high-quality randomised evidence on long-established treatment options (SPS and CPS) and a limited evidence base for hyperkalaemia management with these agents.

A survey demonstrating lack of consensus on the sequence of medications for treatment of hyperkalemia among pediatric critical care providers

OBJECTIVE

Hyperkalemia is one of the reversible causes of cardiac arrest in children. The Advanced Cardiovascular Life Support guidelines have specific recommendations on the choice and sequence of medications for treatment of life-threatening hyperkalemia. However, the Pediatric Advanced Life Support guidelines have no specific treatment recommendations. The objective of this study was to measure the extent to which opinions diverge among pediatricians on the choice and sequence of medication administration in the management of hyperkalemia during cardiac arrest.

DESIGN

Scenario-based survey.

SETTING

A hypothetical hospital area covered by the pediatric rapid response team.

PATIENTS

A hypothetical scenario of a 7-year old child receiving a blood transfusion who is suddenly unresponsive and found to be in pulseless ventricular tachycardia with stat labs revealing a potassium level of 8.3.

INTERVENTIONS

A scenario-based survey of PICU fellows and attendings at a PICU Fellows Boot Camp.

MEASUREMENT AND MAIN RESULTS

Eighty-four fellows and 24 attendings responded to the survey. The response rate was 89%. Calcium was chosen most frequently as the first drug to be administered (calcium chloride, 40/115 [34.8%]; calcium gluconate, 62/115 [53.9%]) while 38 of 115 respondents (33%) chose a drug other than calcium. Only 17 of 115 respondents (15%) would use calcium, sodium bicarbonate, insulin, and dextrose in the advanced cardiovascular life support-recommended sequence. PICU attendings were significantly more likely to administer the advanced cardiovascular life support-recommended sequence than fellows (attendings, 8/24 [33%] vs fellows, 9/84 [11%]; p = 0.007).

CONCLUSION

This survey revealed notable variability in the choice and sequence of medications for treatment of life-threatening hyperkalemia with surprisingly few participants in compliance with the advanced cardiovascular life support hyperkalemia guidelines. A standardized approach for pediatric life-threatening hyperkalemia is recommended to improve resuscitation quality.

Hypokalemia and hyperkalemia in infants and children: pathophysiology and treatment

Potassium is the second most abundant cation in the body. About 98% of potassium is intracellular and that is particularly in the skeletal muscle. Electrical disturbances associated with disorders of potassium homeostasis are a function of both the extracellular and intracellular potassium concentrations. Clinical disorders of potassium homeostasis occur with some regularity, especially in hospitalized patients receiving many medications. This article will review the pathophysiology of potassium homeostasis, symptoms, causes, and treatment of hypo- and hyperkalemia.

A physiologic-based approach to the treatment of acute hyperkalemia

Hyperkalemia is a common and potentially lethal disorder. Given its variable presentation, clinicians should have a high index of suspicion, especially in patients with chronic kidney disease. The present case highlights key physiologic mechanisms in the development of hyperkalemia and provides an outline for emergent treatment. In this context, we discuss specific mechanisms of action of available treatments of hyperkalemia.

Management of hyperkalemia in dialysis patients

Hyperkalemia is common in patients with end-stage renal disease, and may result in serious electrocardiographic abnormalities. Dialysis is the definitive treatment of hyperkalemia in these patients. Intravenous calcium is used to stabilize the myocardium. Intravenous insulin and nebulized albuterol lower serum potassium acutely, by shifting it into the cells. Despite their widespread use, neither intravenous bicarbonate nor cation exchange resins are effective in lowering serum potassium acutely. Prevention of hyperkalemia currently rests largely upon dietary compliance and avoidance of medications that may promote hyperkalemia. Prolonged fasting may provoke hyperkalemia, which can be prevented by administration of intravenous dextrose.

[Daily problems involving contact with terminally ill patients with renal failure]

Practitioners and physicians working in emergency rooms are often confronted with dialysis patients or patients who have received a kidney transplant. For dialysis patients, the mode of dialysis treatment needs to be assessed and dialysis access should be secured. Furthermore, the indications for the next dialysis treatment need to be determined. Dialysis patients often present themselves because of fluid overload, hypo- or hypertensive episodes, electrolyte disturbances, fever or cardiovascular events. Patients undergoing continuous peritoneal dialysis are at an increased risk of infection of the catheter or of peritonitis. Patients with a renal transplant require continuation of their immunosuppression and the function of the transplant should be monitored. These patients often present with infections in which case the degree of immunosuppression may need to be reduced. Vaccinations as well as an increased risk for malignancies require special attention in these patients.