Electrolyte imbalance
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| Water–electrolyte imbalance | |
|---|---|
| Specialty | Nephrology  |
Electrolyte imbalance, or water-electrolyte imbalance, is an abnormality in the concentration of electrolytes in the body. Electrolytes play a vital role in maintaining homeostasis within the body. They help to regulate heart and neurological function, fluid balance, oxygen delivery, acid–base balance and much more. Electrolyte imbalances can develop by consuming too little or too much electrolyte as well as excreting too little or too much electrolyte.
Electrolyte disturbances are involved in many disease processes, and are an important part of patient management in medicine.[1] The causes, severity, treatment, and outcomes of these disturbances can vastly differ depending on the implicated electrolyte.[2] The most serious electrolyte disturbances involve abnormalities in the levels of sodium, potassium or calcium. Other electrolyte imbalances are less common and often occur in conjunction with major electrolyte changes. The kidney is the most important organ in maintaining appropriate fluid and electrolyte balance, but other factors such as hormonal changes and physiological stress play a role.[1] Chronic laxative abuse or severe diarrhea or vomiting (gastroenteritis) can lead to electrolyte disturbances along with dehydration. People suffering from bulimia or anorexia nervosa are at especially high risk for an electrolyte imbalance. At worst, electrolyte imbalance can lead to death by cardiac failure if not treated appropriately and rapidly enough,[3][4][5] as may be observed with the refeeding syndrome.
General function
Electrolytes are important because they are what cells (especially nerve, heart and muscle cells) use to maintain voltages across their cell membranes and to carry electrical impulses (nerve impulses, muscle contractions) across themselves and to other cells.[citation needed] Kidneys work to keep the electrolyte concentrations in blood constant despite changes in the body.[3][5] For example, during heavy exercise, electrolytes are lost in sweat, particularly in the form of sodium and potassium.[5] The kidneys can also generate dilute urine to balance sodium levels.[5] These electrolytes must be replaced to keep the electrolyte concentrations of the body fluids constant. Hyponatremia, or low sodium, is the most commonly seen type of electrolyte imbalance.[6][7]
Treatment of electrolyte imbalance depends on the specific electrolyte involved and whether the levels are too high or too low.[2] The level of aggressiveness of treatment and choice of treatment may change depending on the severity of the disturbance.[2] If the levels of an electrolyte are too low, a common response to electrolyte imbalance may be to prescribe supplementation. However, if the electrolyte involved is sodium, the issue is not a deficiency of sodium, but rather a water excess, causing the imbalance. Supplementation for these people may correct the electrolyte imbalance but at the expense of volume overload, which can be dangerous particularly for neonates.[3] Because each individual electrolyte affects physiological function differently, they must be considered separately when discussing causes, treatment, and complications.
Sodium
Sodium and its homeostasis in the human body is highly dependent on fluids. The human body is approximately 60% water, a percentage which is also known as total body water. The total body water can be divided into two compartments called extracellular fluid (ECF) and intracellular fluid (ICF). The majority of the sodium in the body stays in the extracellular fluid compartment.[8] This compartment consists of the fluid surrounding the cells and the fluid inside the blood vessels. ECF has a sodium concentration of approximately 140 mEq/L.[8] Because cells membranes are permeable to water and not sodium, the movement of water across membranes impacts the concentration of sodium in the blood. Sodium acts as a force that pulls water across membranes, and water moves from places with lower sodium concentration to places with higher sodium concentration. This happens through a process called Osmosis.[8] When evaluating sodium imbalances, both total body water and total body sodium must be considered.[2]
Hypernatremia
Hypernatremia means that the concentration of sodium in the blood is too high. An individual is considered to be have high sodium at levels above 145 mEq/L of sodium. Hypernatremia is not common in individuals with no other health concerns.[2] Most individuals with this disorder have either experienced loss of water from diarrhea, altered sense of thirst, inability to consume water, inability of kidneys to make concentrated urine, or increased salt intake.[2][8]
Causes
There are three types of hypernatremia each with different causes.[2] The first is dehydration along with low total body sodium. This is most commonly caused by heatstroke, burns, extreme sweating, vomiting, and diarrhea.[2] The second is low total body water with normal body sodium. This can be caused by Diabetes insipidus, renal disease, Hypothalamic dysfunction, Sickle cell disease, and certain drugs.[2] The third is increased total body sodium which is caused by increased ingestion, Conn's Disease, or Cushing's syndrome.[2]
Symptoms
Symptoms of hypernatremia may vary depending on type and how quickly the electrolyte disturbance developed.[8] Common symptoms are dehydration, nausea, vomiting, fatigue, weakness, increased thirst, excess urination. Patients may be on medications that caused the imbalance such as Diuretics or Nonsteroidal anti-inflammatory drugs.[8] Some patients may have no obvious symptoms at all.[8]
Treatment
It is crucial to first assess the stability of the patient. If there are any signs of shock such as Tachycardia or Hypotension, these must be treated immediately with IV saline infusion.[2][8] Once the patient is stable, it is important to identify the underlying cause of hypernatremia as that may affect the treatment plan.[2][8] The final step in treatment is to calculate the patients free water deficit, and to replace it at a steady rate using a combination of oral or IV fluids.[2][8] The rate of replacement of fluids varies depending on how long the patient has been hypernatremic. Lowering the sodium level too quickly can cause cerebral edema.[8]
See also
References
- ^ a b Balcı, Arif Kadri; Koksal, Ozlem; Kose, Ataman; Armagan, Erol; Ozdemir, Fatma; Inal, Taylan; Oner, Nuran (2013). "General characteristics of patients with electrolyte imbalance admitted to emergency department". World Journal of Emergency Medicine. 4 (2): 113–116. doi:10.5847/wjem.j.issn.1920-8642.2013.02.005. ISSN 1920-8642. PMC 4129840. PMID 25215103.
- ^ a b c d e f g h i j k l m Walls, Ron M.; Hockberger, Robert S.; Gausche-Hill, Marianne (2018). Rosen's Emergency Medicine: Concepts and Clinical Practice. Philadelphia, PA: Elsevier. pp. 1516–1532. ISBN 978-0-323-35479-0.
- ^ a b c Bockenhauer, D; Zieg, J (September 2014). "Electrolyte disorders". Clinics in Perinatology. 41 (3): 575–90. doi:10.1016/j.clp.2014.05.007. PMID 25155728.
- ^ Tisdall, M; Crocker, M; Watkiss, J; Smith, M (January 2006). "Disturbances of sodium in critically ill adult neurologic patients: a clinical review". Journal of Neurosurgical Anesthesiology. 18 (1): 57–63. doi:10.1097/01.ana.0000191280.05170.0f. PMC 1513666. PMID 16369141.
- ^ a b c d Moritz, ML; Ayus, JC (November 2002). "Disorders of water metabolism in children: hyponatremia and hypernatremia". Pediatrics in Review. 23 (11): 371–80. doi:10.1542/pir.23-11-371. PMID 12415016.
- ^ Dineen, R; Thompson, CJ; Sherlock, M (June 2017). "Hyponatraemia – presentations and management". Clinical Medicine. 17 (3): 263–69. doi:10.7861/clinmedicine.17-3-263. PMC 6297575. PMID 28572229.
- ^ Ályarez L, E; González C, E (June 2014). "[Pathophysiology of sodium disorders in children]". Revista chilena de pediatria (Review). 85 (3): 269–80. doi:10.4067/S0370-41062014000300002. PMID 25697243.
- ^ a b c d e f g h i j k Tintinalli, Judith E.; Stapczynski, J. Stephan; Ma, O. John; Yealy, Donald M.; Meckler, Garth D.; Cline, David M. (2016). Tintinalli's Emergency Medicine: A Comprehensive Study Guide. New York, NY: McGraw-Hill. ISBN 978-0-07-179476-3.