Hyperkalemic periodic paralysis

What is hyperkalemic periodic paralysis?

Hyperkalemic periodic paralysis is a condition that causes episodes of extreme muscle weakness or paralysis, usually beginning in infancy or early childhood. Most often, these episodes involve a temporary inability to move muscles in the arms and legs. Episodes tend to increase in frequency until mid-adulthood, after which they occur less frequently. Factors that can trigger attacks include rest after exercise, potassium-rich foods such as bananas and potatoes, stress, fatigue, alcohol, pregnancy, exposure to cold temperatures, certain medications, and periods without food (fasting). Muscle strength usually returns to normal between attacks, although many affected people continue to experience mild stiffness (myotonia), particularly in muscles of the face and hands.

Most people with hyperkalemic periodic paralysis have increased levels of potassium in their blood (hyperkalemia) during attacks. Hyperkalemia results when the weak or paralyzed muscles release potassium ions into the bloodstream. In other cases, attacks are associated with normal blood potassium levels (normokalemia). Ingesting potassium can trigger attacks in affected individuals, even if blood potassium levels do not go up.

How common is hyperkalemic periodic paralysis?

Hyperkalemic periodic paralysis affects an estimated 1 in 200,000 people.

What genes are related to hyperkalemic periodic paralysis?

Mutations in the SCN4A gene can cause hyperkalemic periodic paralysis. The SCN4A gene provides instructions for making a protein that plays an essential role in muscles used for movement (skeletal muscles). For the body to move normally, these muscles must tense (contract) and relax in a coordinated way. One of the changes that helps trigger muscle contractions is the flow of positively charged atoms (ions), including sodium, into muscle cells. The SCN4A protein forms channels that control the flow of sodium ions into these cells.

Mutations in the SCN4A gene alter the usual structure and function of sodium channels. The altered channels stay open too long or do not stay closed long enough, allowing more sodium ions to flow into muscle cells. This increase in sodium ions triggers the release of potassium from muscle cells, which causes more sodium channels to open and stimulates the flow of even more sodium ions into these cells. These changes in ion transport reduce the ability of skeletal muscles to contract, leading to episodes of muscle weakness or paralysis.

In 30 to 40 percent of cases, the cause of hyperkalemic periodic paralysis is unknown. Changes in other genes, which have not been identified, likely cause the disorder in these cases.

Read more about the SCN4A gene.

How do people inherit hyperkalemic periodic paralysis?

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.

In most cases, an affected person has one parent with the condition.

Where can I find information about diagnosis or management of hyperkalemic periodic paralysis?

These resources address the diagnosis or management of hyperkalemic periodic paralysis and may include treatment providers.

• Gene Review: Hyperkalemic Periodic Paralysis Type 1
• Genetic Testing Registry: Familial hyperkalemic periodic paralysis
• Genetic Testing Registry: Hyperkalemic Periodic Paralysis Type 1
• Lab Tests Online: Potassium
• MedlinePlus Encyclopedia: Hyperkalemic Periodic Paralysis
• Periodic Paralysis International: How is Periodic Paralysis Diagnosed?

You might also find information on the diagnosis or management of hyperkalemic periodic paralysis in Educational resources and Patient support.

General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.

To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.

Where can I find additional information about hyperkalemic periodic paralysis?

THANKS :   http://ghr.nlm.nih.gov/condition/hyperkalemic-periodic-paralysis

Hyperkalemic periodic paralysis

Hyperkalemic periodic paralysis (HYPP, HyperKPP) is a genetic disorder that occurs in horses and humans, where it is also known as Impressive syndrome. It is aninherited autosomal dominant disorder that affects sodium channels in muscle cells and the ability to regulate potassium levels in the blood. It is most commonly associated with horses, but occurs in humans, where it may be called Gamstorp episodic adynamy. It is characterized by muscle hyperexcitability or weakness which, exacerbated by potassiumor cold, can lead to uncontrolled shaking followed by paralysis. Onset in humans usually occurs in early childhood.

The mutation which causes this disorder is dominant on SCN4A with linkage to thesodium channel expressed in muscle. The mutation causes single amino acid changes in parts of the channel which are important for inactivation. In the presence of high potassium levels, including those induced by diet, sodium channels fail to inactivate properly.

Equine hyperkalaemic periodic paralysis occurs in 1 in 50 quarter horses and can be traced to a single ancestor, a stallion namedImpressive.

Thanks:   http://en.wikipedia.org/wiki/Hyperkalemic_periodic_paralysis

Trastornos del potasio

1. Introducción

Las alteraciones del metabolismo del potasio se encuentran entre las más frecuentes en la práctica clínica. Su espectro de gravedad es variable, desde la hipopotasemia leve inducida por diuréticos a la hiperpotasemia grave de consecuencias fatales. Tanto la hipopotasemia como la hiperpotasemia ocasionan alteraciones de la polarización de la membrana celular que dan lugar a diversas manifestaciones clínicas, de las que las más graves son las que afectan al sistema cardiovascular.

2. Factores reguladores de la homeostasis del potasio

La concentración de potasio plasmático es el resultado de la relación entre su ingesta, eliminación y distribución transcelular. Los requerimientos mínimos diarios de potasio son de unos 1.600-2.000 mg (40-50 mmol; 40 mg = 1 mmol). Su principal vía de eliminación es la renal. Aproximadamente el 80% del potasio ingerido es excretado por los riñones, el 15% por el tracto gastrointestinal y el 5% restante por el sudor.

Continúen en esta página:           http://nefrologiadigital.revistanefrologia.com/modules.php?name=libro&op=viewCap&idpublication=1&idedition=13&idcapitulo=63

What are the symptoms of low potassium?

Potassium affects the way neuromuscular cells discharge energy (depolarize) and then regenerate (repolarize) that energy to be able to fire again. When potassium levels are low, the cells cannot repolarize and are unable to fire repeatedly, so the  muscles and nerves can function normally. The effects of low potassium include can cause the following symptoms:

• muscle weakness,
• muscle aches,
• muscle cramps, and
• palpitations (irregular heartbeats)

How is low potassium diagnosed?

Potassium levels in the blood may be easily measured by routine blood tests.

Low potassium is often a potential complication of medication, for example, patients with high bloodpressure who are being treated with diuretics such as hydrochlorothiazide (Hydrodiuril) or furosemide (Lasix) often have their potassium levels monitored.

Patients who become ill with vomiting and diarrhea, may develop dehydration And  weakness. Part of the patient evaluation may include having theirelectrolyte levels tested in order to determine whether body potassium losses may need to be replaced.

There can be electrocardiogram (EKG, ECG) changes associated with low potassium, and sometimes the diagnosis of low potassium is made incidentally by finding the characteristic "U" waves on the EKG tracing. In severe cases, hypokalemia can lead to dangerous disturbances in heart rhythm (dysrhythmia).

Treatment of Hypokalemia in Children

Potassium less than 3.5 mEq / L but not less than 3 mEq / L

In general it is sufficient to increase the contribution to 1 or 2 mEq per 100 mL of water intake calculated as if fasting or potassium salts administered orally if this diet.

Potassium Less than 3 mEq / L but not less than 2 mEq / L

Check with serum determination

Taking electrocardiogram tracing if 12 lead better.

If hypokalemia data with electrocardiographic effect, administer potassium to 0.5 mEq per kg of body weight diluted in 100 mL 4mEq SSF for peripherally to 1 mEq plus 5 mL of SSF if the patient is fluid restriction and has central catheter .

Potassium less than 2 mEq / L

Check potassium levels

Take ECG and ECG changes secondary to verify hipokelemia.

Administer 1 mEq potassium per kg, for each mEq of potassium calculated, add 5 mL of 0.9% saline or 5% glucose solution or double-distilled water for central line and up to 4 mEq / l by the peripheral route.

Not everything ends there, you should increase the amount of potassium in parenteral solutions, between 1-2 mEq per 100 mL of solution administered.

Always after each load of potassium should be checked a new ECG tracing and blood levels.

Analyze each particular case, for example patients with amphotericin require high potassium contributions due to an increase in glomerular membrane permeability to this ion, we have had cases in which potassium intake can reach 150-200 mEq m2sc .

Keep magnesium levels within normal limits, as the conditions hypomagnesemia renal potassium loss.

THANKS TO:http://cuidadosintensivospediatricos.com/2013/04/29/tratamiento-de-la-hipokalemia-en-ninos/

Tratamiento de la Hipokalemia en Niños

Potasio menor de 3.5 mEq/L pero no menor de 3 mEq/L

1. En general es suficiente con incrementar el aporte en 1 o 2 mEq por cada 100 mL de solución calculada como aporte hídrico si esta en ayuno o administrar sales de potasio por vía oral si esta con dieta.

Potasio Menor de 3 mEq/L pero no menor de 2 mEq/L

1. Verificar con determinación sérica
2. Tomar trazo de electrocardiograma, si es de 12 derivaciones mejor.
3. Si hay datos de hipokalemia con repercusión electrocardiográfica, administrar potasio a 0.5 mEq por Kg de peso diluidos 4 mEq en 100 mL de SSF para vía periférica  y 1 mEq mas 5 mL de SSF si el paciente se encuentra con restricción de líquidos y tiene catéter central.

Potasio menor de 2 mEq/L

1. Verifica los niveles de potasio
2. Tomar electrocardiograma y verificar alteraciones electrocardiográficas secundarias a hipokelemia.
3. Administrar potasio a 1 mEq por cada kg, por cada mEq de potasio calculado, agregar 5 mL de solución salina al 0.9%  o solución glucosa al 5% o agua bidestilada, por vía central y máximo 4 mEq/l por vía periférica.
4. No todo termina ahí, se debe incrementar el aporte de potasio en las soluciones parenterales, entre 1 – 2 mEq por cada 100 mL de solución administrada.
5. Siempre después de cada carga de potasio se deberá verificar un nuevo trazo electrocardiográfico y niveles en sangre.
6. Analiza cada caso en particular, por ejemplo los pacientes con anfotericina requieren aportes elevados de potasio debido a un aumento en la permeabilidad de la membrana glomerular a este ión, hemos tenido casos en lo que el aporte de potasio puede llegar hasta 150 – 200 mEq m2sc.

Mantén los niveles de magnesio en límites normales, ya que la hipomagnesemia condiciona pérdida renal de potasio.

 

INFORMACIÓN OBTENIDA EN: http://cuidadosintensivospediatricos.com/2013/04/29/tratamiento-de-la-hipokalemia-en-ninos/

Hipokaliemia o hipopotasemia - Definición

Definición

La hipopotasemia significa una disminución en la cantidad de potasio que contiene la sangre. 

Causas

Puede ser debida a la pérdida excesiva de potasio por la orina o por el intestino como en el caso de diarreas importantes, vómitos graves o la ingesta inadecuada ... 
Algunos medicamentos también pueden estar implicados. Los síntomas pueden incluir debilidad muscular o calambres, estreñimiento, aumento de la sed y de la cantidad de orina. La principal complicación son los problemas como por ejemplo las arritmias. 

Tratamiento

Mediante un análisis de sangre se puede determinar la dosis de potasio en sangre y cuantificar la pérdida. Además de tratar las causas que la han provocado los suplementos de potasio pueden ser necesarios en caso de deficiencia severa.



Continuen aqui: http://salud.kioskea.net/faq/10308-hipokaliemia-o-hipopotasemia-definicion

The Fight Against Hypokalemic Periodic Paralysis

Family and HKPP

Big news from my corner of the world. As of this week..........

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A calcium channel mutation causing hypokalemic periodic paralysis

https://www.uni-ulm.de/fileadmin/website_uni_ulm/med.herti/Forschungsprojekte/Publikationen_Downloads/Periodic_paralyses/A_Ca_channel_mutation_causing_hypokalemic_PP_Hum_Mol_Genet_1994.pdf

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