Electrolyte disturbance

For patient information, click here

WikiDoc Resources for Electrolyte disturbance
Articles
Most recent articles on Electrolyte disturbance Most cited articles on Electrolyte disturbance Review articles on Electrolyte disturbance Articles on Electrolyte disturbance in N Eng J Med, Lancet, BMJ
Media
Powerpoint slides on Electrolyte disturbance Images of Electrolyte disturbance Photos of Electrolyte disturbance Podcasts & MP3s on Electrolyte disturbance Videos on Electrolyte disturbance
Evidence Based Medicine
Cochrane Collaboration on Electrolyte disturbance Bandolier on Electrolyte disturbance TRIP on Electrolyte disturbance
Clinical Trials
Ongoing Trials on Electrolyte disturbance at Clinical Trials.gov Trial results on Electrolyte disturbance Clinical Trials on Electrolyte disturbance at Google
Guidelines / Policies / Govt
US National Guidelines Clearinghouse on Electrolyte disturbance NICE Guidance on Electrolyte disturbance NHS PRODIGY Guidance FDA on Electrolyte disturbance CDC on Electrolyte disturbance
Books
Books on Electrolyte disturbance
News
Electrolyte disturbance in the news Be alerted to news on Electrolyte disturbance News trends on Electrolyte disturbance
Commentary
Blogs on Electrolyte disturbance
Definitions
Definitions of Electrolyte disturbance
Patient Resources / Community
Patient resources on Electrolyte disturbance Discussion groups on Electrolyte disturbance Patient Handouts on Electrolyte disturbance Directions to Hospitals Treating Electrolyte disturbance Risk calculators and risk factors for Electrolyte disturbance
Healthcare Provider Resources
Symptoms of Electrolyte disturbance Causes & Risk Factors for Electrolyte disturbance Diagnostic studies for Electrolyte disturbance Treatment of Electrolyte disturbance
Continuing Medical Education (CME)
CME Programs on Electrolyte disturbance
International
Electrolyte disturbance en Espanol Electrolyte disturbance en Francais
Business
Electrolyte disturbance in the Marketplace Patents on Electrolyte disturbance
Experimental / Informatics
List of terms related to Electrolyte disturbance

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Synonyms and keywords: abnormal electrolytes, abnormal lytes, lytes

Overview

Electrolytes are electrically charged solutes necessary to maintain body homeostasis. The main electrolytes include Sodium (Na), Potassium (K), Chloride (Cl), Calcium (Ca), Phosphorus (P), and Magnesium (Mg). These electrolytes are involved in multiple physiologic and neurohormonal reactions necessary to maintain neuromuscular, neuronal, myocardial, and acid-base balance. Their balance are mainly regulated by renal and endocrine systems, any changes in their balance may be life threatening. Electrolytes are in balance to achieve neutral electrical charges. Electrolytes could be classified based on their electrical charge to Anions and Cations. Anions include Bicarbonate, Chloride, and Phosphorus. Cations are Calcium, Magnesium, Potassium, and Sodium. Sodium and Chloride are the major extracellular ions that has the greatest impact on serum osmolality (solute concentration in 1 liter of water). Calcium and bicarbonate are the other major extracellular electrolytes. Main intracellular electrolytes are, Potassium, Phosphorus, and Magnesium.

Nomenclature

There is a standard nomenclature for electrolyte disorders:

1. The name starts with a prefix denoting whether the electrolyte is abnormally elevated ("hyper-") or depleted ("hypo-").
2. The word stem then gives the name of the electrolyte in Latin. If no Latin equivalent exists, then the corresponding term in English is used.
3. The name ends with the suffix "-emia," meaning "in the blood." (Note, this doesn't mean that the disturbance is only in the blood; usually, electrolyte disturbance is systemic. However, since the disturbance is usually detected from blood testing, the convention has developed.)

For instance, elevated potassium in the blood is called "hyperkalemia" from the Latin term for potassium, "kalium".

Causes

• Drug side effect: Hydrochlorothiazide, Pergolide

Table of common electrolyte disturbances

Electrolyte	Ionic formula	Normal limits (mg/dl)	Elevation disorder	Depletion disorder
Sodium	Na+	135-145	hypernatremia	hyponatremia
Potassium	K+	3.5-5	hyperkalemia	hypokalemia
Calcium	Ca2+	8.9-10.1	hypercalcemia	hypocalcemia
Magnesium	Mg2+	1.5-2.5	hypermagnesemia	hypomagnesemia
Chloride	Cl-	96-106	hyperchloremia	hypochloremia
Phosphate	PO43-	2.5-4.5	hyperphosphatemia	hypophosphatemia
Bicarbonate	HCO3-	22-28 (mmol/l)	hyperbicarbonatemia	hypobicarbonatemia

General Function

Electrolytes are important because they are what your cells (especially nerve, heart, muscle) use to maintain voltages across their cell membranes and to carry electrical impulses (nerve impulses, muscle contractions) across themselves and to other cells. Your kidneys work to keep the electrolyte concentrations in your blood constant despite changes in your body. For example, when you exercise heavily, you lose electrolytes in your sweat, particularly sodium and potassium. These electrolytes must be replaced to keep the electrolyte concentrations of your body fluids constant.

Electrolyte Abnormalities and ECG Changes

The most notable feature of hyperkalemia is the "tent shaped" or "peaked" T wave. Delayed ventricular depolarization leads to a widened QRS complex and the P wave becomes wider and flatter. When hyperkalemia becomes severe, the ECG resembles a sine wave as the P wave disappears from view. In contrast, hypokalemia is associated with flattenting of the T wave and the appearance of a U wave. When untreated, hypokalemia may lead to severe arrhythmias.

The fast ventricular depolarization and repolarization associated with hypercalcemia lead to a characteristic shortening of the QT interval. Hypocalcemia has the opposite effect, lengthening the QT interval.

Differentiating electrolyte disturbances from other diseases

Electrolyte disturbance must be differentiated from other causes of headache, altered mental status and seizures such as brain tumors and delirium trmemns.

Diseases	Diagnostic tests				Physical Examination					Symptoms			Past medical history	Other Findings
	Na+, K+, Ca2+	CT /MRI	CSF Findings	Gold standard test	Neck stiffness	Motor or Sensory deficit	Papilledema	Bulging fontanelle	Cranial nerves	Headache	Fever	Altered mental status
Brain tumour		?	Cancer cells	MRI		?	?	?	?	?		?		Cachexia, gradual progression of symptoms
Delerium Tremens		?		Clinical diagnosis		?	?		?	?	?	?	Alcohal intake, sudden witdrawl or reduction in consumption	Tachycardia, diaphoresis, hypertension, tremors, mydriasis, positional nystagmus, tachypnea
Subarachnoid hemorrhage		?	Xanthochromia	CT scan without contrast	?	?	?	?	?	?	?	?	Trauma/fall	Confusion, dizziness, nausea, vomiting
Stroke		?	Normal	CT scan without contrast		?	?		?	?		?	TIAs, hypertension, diabetes mellitus	Speech difficulty, gait abnormality
Neurosyphilis		?	? Leukocytes and protein	CSF VDRL-specifc CSF FTA-Ab -sensitive	?	?	?	?		?		?	Unprotected sexual intercourse, STIs	Blindness, confusion, depression, Abnormal gait
Viral encephalitis		?	Increased RBCS or xanthochromia, mononuclear lymphocytosis, high protein content, normal glucose	Clinical assesment	?	?	?		?	?	?	?	Tick bite/mosquito bite/ viral prodome for several days	Extreme lethargy, rash hepatosplenomegaly, lymphadenopathy, behavioural changes
Herpes simplex encephalitis		?		Clinical assesment			?	?	?	?	?		History of hypertension	Delirium, cortical blindness, cerebral edema, seizure
Wernicke’s encephalopathy			Normal				?	?			?		History of alcohal abuse	Ophthalmoplegia, confusion
CNS abscess		?	? leukocytes >100,000/ul, ? glucose and ? protien, ? red blood cells, lactic acid >500mg	Contrast enhanced MRI is more sensitive and specific, Histopathological examination of brain tissue	?	?	?		?	?	?	?	History of drug abuse, endocarditis, ? immune status	High grade fever, fatigue,nausea, vomiting
Drug toxicity											?	?		Lithium, Sedatives, phenytoin, carbamazepine
Conversion disorder				Diagnosis of exclusion		?		?		?	?	?		Tremors, blindness, difficulty swallowing
Electrolyte disturbance	? or ?			Depends on the cause						?		?		Confusion, seizures
Febrile seizures			Not performed in first simple febrile seizures	Clinical diagnosis and EEG					?	?	?	?	Family history of febrile seizures, viral illness or gastroenteritis	Age > 1 month,
Subdural empyema		?		Clinical assesment and MRI	?	?	?	?	?			?	History of relapses and remissions	Blurry vision, urinary incontinence, fatigue
Hypoglycemia	? or ?			Serum blood glucose HbA1c		?				?		?	History of diabetes	Palpitations, sweating, dizziness, low serum, glucose

ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death (DO NOT EDIT)

Recommendations for Electrolyte Disturbances

Class I

"1. Potassium (and magnesium) salts are useful in treating ventricular arrhythmias secondary to hypokalemia (or hypomagnesmia) resulting from diuretic use in patients with structurally normal hearts. (Level of Evidence: B)"

Class IIa

"1. It is reasonable to maintain serum potassium levels above 4.0 mM/L in any patient with documented life-threatening ventricular arrhythmias and a structurally normal heart. (Level of Evidence: C)"

"2. It is reasonable to maintain serum potassium levels above 4.0 mM/L in patients with acute MI. (Level of Evidence: B)"

"3. Magnesium salts can be beneficial in the management of VT secondary to digoxin toxicity in patients with structurally normal hearts. (Level of Evidence: B)"

Related Chapters

• Acidosis
• Alkalosis
• Dehydration
• Malnutrition
• Starvation

Template:WikiDoc Sources