Importance of determination of body fluid electrolytes in emergency clinical conditions
Editors:
- Dr. Praful B. Godkar (Ph.D)
Eminent Author, Medical Biochemist and Scientist, Technical Education consultant. AGD Biomedicals (Pvt) LTD. - Dr. Gauri Kulkarni MD (Pathology)
AGD Biomedicals (Pvt) LTD.
Electrolyte imbalances in body fluids lead to many serious emergency and insidious clinical conditions and point of care (POCT) IVD tests for diagnosing electrolyte imbalances could be an important part of patient management(1-4,12) (Ref. Case study). The causes, severity, treatment, and outcomes of electrolyte imbalances differ on the basis of implicated electrolytes(12). Derangement in electrolyte metabolism occurs frequently in patients with infectious diseases and also in diseases related to endocrine glands(4). Elderly, pregnant female and infants are mainly vulnerable to the electrolyte disorders(5). The most serious electrolyte disturbances involve abnormalities in the levels of major electrolytes such as sodium, potassium, chlorides, bicarbonate and calcium. Electrolyte analysers based of the fifth generation IVD tests can diagnose a clinical condition related to electrolyte imbalances accurately and precisely in less than five minutes and could significantly impact management and patient outcomes(12).
Note : Electrolyte imbalances can be a contributing factor to death in various emergency situations. It is important to note that they often occur alongside other health issues, and the severity of the electrolyte imbalance plays a significant role in the treatment outcome.
Q1. What are electrolytes?
ANS: The electrolyte is a substance containing free ions that make the substance electrically conductive. Electrolytes are electrically charged. Main body fluid electrolytes are sodium, potassium, chlorides, bicarbonate and calcium.
Q2. What are the various functions of electrolytes?
ANS:The maintenance of osmotic pressure and water distribution in the various body compartments is the primary function of four major electrolytes such as sodium, potassium, chlorides, and bicarbonate. In addition to homeostasis, these electrolytes also play an important role in the maintenance of blood pH, proper heart and muscle functions, normal oxidation-reduction reactions, and as co-factors for enzyme activities. Almost all metabolic reactions are dependent on balanced amounts of electrolytes.
Q3. What are common emergency clinical conditions that may cause electrolyte imbalance?
ANS: Emergency clinical conditions are the conditions which require immediate medical attention as they can cause potential harm or even death if unattended to. Some of the clinical conditions that can cause electrolyte imbalance include severe dehydration, kidney disease, gastrointestinal disorders (like severe vomiting or diarrhea), certain endocrine disorders (like adrenal insufficiency or diabetes), and severe burns. These conditions can disrupt the body’s ability to regulate electrolyte levels, leading to imbalances that can be life-threatening if not addressed promptly.
Q4. What are the specific symptoms associated with electrolyte imbalance?
ANS : The specific symptoms associated with electrolyte imbalance are: Headache, fatigue, confusion, muscle weakness, cramps, irregular heartbeat, dizziness, numbness in the limbs and extremities, changes in urination, confusion, and irritability.
CASE STUDY
A 65-year-old man visited a physician with postural deformity, severe muscular weakness, nausea, headache, vomiting, and stupor. From the history of the patient it was found out that, he was hypertensive and was being treated by calcium channel-blocker drugs. He was not diabetic and his thyroid function tests were normal. His blood examination reports related to serum electrolytes were as follows:
| TEST | RESULT | REFERENCE RANGE |
| Serum sodium | 120 mEq/l | 133–146 mEq/l |
| Serum potassium | 3.8 mEq/l | 3.8–5.6 mEq/l |
| Serum chlorides | 90 mEq/l | 95–106 mEq/l |
Q5. What is the probable diagnosis?
ANS : Hyponatremia (Low level of serum sodium in blood circulation).
Q6. What is the biochemical basis for the significant decrease in serum sodium of a patient?
ANS :
The various reasons for low serum sodium could be as follows:
(A) Older individuals are more prone to hyponatremia due to impaired water-excretory capacity which is specifically attributed to aging-related decrease of glomerular filtration rate (GFR).
(B) Inappropriate antidiuretic hormone secretion (SIAD) which is more frequently observed in elderly persons(13).
(C ) Diuretics are one of the most common causes of hyponatremia in the elderly. Thiazide diuretics are usually associated with hyponatremia(6).
(D) A wide range of psychotropic medications, including antipsychotic drugs (butyrophenones), benzodiazepines, phenothiazines and antidepressants, is associated with hyponatremia(7).
(E) Pituitary adrenal dysfunction(11): Adrenal insufficiency is caused by Primary Addison’s disease: Dysfunction of the adrenal gland by self-antibody destruction, failure of development of adrenal gland (e.g., adrenal dysgenesis), or enzyme deficiency (e.g., congenital adrenal hyperplasia). Adrenal insufficiency also takes place due to adrenocorticotropic hormone (ACTH) deficiency (Secondary Addison’s disease) or in deficiency of corticotropic releasing hormone (CRH) deficiency (Tertiary Addison’s disease).
Note
ACTH and CRH play important role in the regulation of adrenal function. In Adrenal insufficiency the adrenal glands do not produce adequate amounts of steroid hormones such as cortisol and mineralocorticoids. These hormones are important in regulating electrolytes, blood pressure, and various metabolic reactions. Deficiency of these hormones leads to symptoms such as fatigue, vomiting, abdominal pain, muscle weakness, low blood pressure, depression, mood changes, etc. In severe cases (Adrenal crisis) a patient may suffer from organ failure and shock.
(F) Uncontrolled diabetes mellitus can also induce osmotic diuresis and hypovolemic hyponatremia(8).
(G) “Tea and toast” hyponatremia: This type of hyponatremia may occur in elderly individuals with a low glomerular filtration rate (GFR); who follow a diet poor in salt and protein but drink a large amount of water.
(H) Hyponatremia, or low sodium levels in the blood, can occur in patients with hypothyroidism, particularly in severe cases of myxedema(8).
(I) Pseudohyponatremia: It is observed in patients with hyperproteinemia (In multiple myeloma and other monoclonal gammopathies, with intravenous immunoglobulin administration) and in severe hyperlipidemia (hypertriglyceridemia and hypercholesterolemia)(14).
Note
(1) The reasons indicated in points A, B and C could be applicable in this Case. Refer points A and E respectively: Determination of Glomerulus Filtration Rate (GFR) and levels of serum Cortisol in the morning and afternoon sessions could be useful to arrive at the right diagnosis.
(2) Simultaneous determination of urine and serum osmolarity (SPOT osmolarity test) could be useful to find out Syndrome of Inappropriate Antidiuretic Hormone secretion (SIAD). Urine osmolarity/Serum osmolarity > 1.0 indicates concentration of solutes in urine are more than in serum and indicates SIAD.
Q7. What additional laboratory tests are recommended?
ANS :
- Determination of GFR,
- Determination of SPOT test for Urine and Serum osmolarity, and
- Serum cortisol (8 am and 2 pm).
Q8. What is the biochemical basis for severe muscular weakness in sodium deficiency?
ANS : Severe muscular weakness in sodium deficiency, is mainly due to the disruption of nerve and muscle functions. Adequate sodium ions are required for nerve impulses that trigger muscle contractions. When plasma sodium levels decrease below normal levels, this process is impaired, leading to muscle weakness, cramps and spasms.
Q9. Why a person with sodium deficiency suffers from postural deformity?
ANS : Low sodium levels may lead to cerebral edema, leading to increased intracranial pressure and neurological symptoms, which can manifest as impaired balance, gait disturbances, and an increased risk of falls, all these conditions leading to postural abnormalities.
References
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(11) Huecker, Martin R.; Bhutta, Beenish S.; Dominique, Elvita (2022), “Adrenal Insufficiency”, StatPearls, Treasure Island (FL): StatPearls Publishing, PMID 28722862, retrieved 2022-11-02.
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(13) Rainer U. Pliquett, MD and Nicholas Obermüller, MD. Endotext. December 22, 2022.
(14) Aziz, Fahad; Sam, Ramin; Lew, Susie Q.; Massie, Larry; Misra, Madhukar; Roumelioti, Maria-Eleni; Argyropoulos, Christos P.; Ing, Todd S.; Tzamaloukas, Antonios H. (2023-06-15). “Pseudohyponatremia: Mechanism, Diagnosis, Clinical Associations and Management”. Journal of Clinical Medicine. 12 (12). MDPI AG: 4076. doi:10.3390/jcm12124076. ISSN 2077-0383. PMC 10299669. PMID 37373769.
