Hypokalemia resident survival guide

Revision as of 16:28, 29 July 2018 by Iqra Qamar (talk | contribs) (→‎Causes)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Rim Halaby, M.D. [2] Iqra Qamar M.D.[3]

Overview

Hypokalemia is defined as plasma potassium concentration less than 3.5 mEq/L. Hypokalemia may present as ileus, muscle cramps, rhabdomyolysis, and polyuria. Electrocardiography findings may include U wave, flat or inverted T waves, prolonged QT interval, and ventricular ectopy.

Causes

Life Threatening Causes

Life-threatening conditions which may result in death or permanent disability within 24 hours if left untreated. Severe hypokalemia may be life-threatening and must be treated as such irrespective of the underlying cause.

Common Causes

Shown below is a table summarizing the different pathophysiological processes that can lead to hypokalemia.

Trans-cellular shifts Renal loss GI loss Increased hematopoiesis Decreased intake of potassium

Subject is normo or hypotensive
Associated with acidosis

Associated with alkalosis

Variable acid/base status

Subject is hypertensive
Primary hyperaldosteronism

  • Conn's syndrome

Secondary hyperaldosteronism

  • Renovascular disease
  • Renin secreting tumor

Non aldosterone increase in mineralcorticoid

Associated with metabolic acidosis

Associated with metabolic alkalosis


Diseases Clinical manifestations Para−clinical findings Gold standard Additional findings
Symptoms Physical examination
Lab Findings Imaging
Fatigue Fever Urinary symptoms Blood Pressure Skin lesions Edema ABG Urinalysis Transtubular potassium gradient Urine Potassium:Creatinine Other Ultrasonography CT scan
Polyuria Oliguria Nocturia
Renal and adrenal disorders Loop diuretic use[1] +/− − + − +/− ↓ − + Metabolic alkalosis ↑K+ > 7 >20mEq/g ↑Na+ − − History of medication use −
Primary hyperaldosteronism[2] + − + − + ↑ Facial flushing − Metabolic alkalosis ↑K+, ↓Na+ ↓PRA, ↑PAC, ↓Na+ Unilateral adrenal hyperplasia Hypodense unilateral adrenal macroadenoma (>1 cm)  PAC:PRA ratio Mood disturbance, paresthesia, muscle cramps
Cushing syndrome[3] + +/− +/− − − ↑ Facial plethora, purple striae + Metabolic alkalosis Glucosuria ↑BS Unilateral adrenal hyperplasia − Urinary free cortisol (24−hour) Dorsicocervical fat pad, obesity, hirsutism
Hemodialysis[4] +/− +/− +/− − − Normal Pustular lesions − Metabolic alkalosis Normal ↓Na+ − − History Carpal tunnel syndrome
Bartter syndrome[5] + − + − +/− Normal or ↓ − − Metabolic alkalosis ↑K+, ↑Ca+2, ↑Cl- − − − Laboratory findings Mental retardation, sensorineural hearing loss
Gitelman syndrome[6] + − + − + Normal − − Metabolic alkalosis ↑K+, ↓Ca+2, ↑Cl- − − − Laboratory findings Growth retardation, tetany, muscle cramp
Liddle syndrome[7] − − +/− − − ↑ − +/− Metabolic alkalosis ↑K+, ↓Na+ ↓PRA, ↓PAC − − Laboratory findings Pseudohyperaldosteronism
Gastrointestinal disorders GI bleeding[8] + − − + − ↓ − − Normal Normal < 3 < 20 mEq/g Anemia − − Laboratory findings Orthostatic hypotension, bradycardia
Vomiting[9] + − − + − ↓ − − Metabolic alkalosis Cl- <20 mEq/L − − − Laboratory findings Dry mucous membranes, lethargy
Severe diarrhea[10] + − − + − ↓ − − Metabolic alkalosis K+<20 mEq/L − − − Laboratory findings Dry mucous membranes, lethargy
Villous adenoma[11] + − − + − ↓ − − Normal K+ and Cl- <20 mEq/L Anemia − − Colonoscopy Hematochezia
VIPoma[12] + +/− − + − ↓ Facial flushing, skin rash + Normal K+<20 mEq/L Stool osmolar gap <50 mOsm/kg Endoscopic ultrasound for VIPomas of 2−3 mm Pancreatic VIPomas >3 cm Laboratory findings Weight loss
Neuropsychiatric disorders Primary polydipsia[13] − − + − + Normal − +/− Normal ↓Urine osmolarity ↓Na+ − − Water restriction test Psychosis
Central diabetes insipidus[14] + − + − + Normal or ↓ − − Normal ↓Urine osmolarity ↑Na+ − − Water restriction test Ischemic encephalopathy
Bulimia nervosa[15] − − − +/− − Normal or ↓ Asteatotic skin Carotenodermia − Normal ↑K+, ↓Cl- − − − Psychological interview  Parotid gland enlargement, lanugo−like hair
Anorexia nervosa[16] + − − +/− − ↓ Xerosis, hair effluvium − Normal ↑K+, ↓Cl- − − − Psychological interview Orthostatic hypotension, bradycardia
Hypokalemic periodic paralysis[17] + − − − +/− Normal or ↓ − +/− Metabolic alkalosis K+<20 mEq/L Thyrotoxicosis, ↓Mg+, ↓PO4-3 − − Laboratory findings Paralytic episodes, arrhythmias
Systemic diseases Hypothermia[18] − − − +/− − Normal Frostbite − Normal Normal − − − Clinical findings Impaired mental state
Alcoholism[19] + +/− + − + Normal or ↓ Icterus, caput medusae + Metabolic alkalosis Ketonuria Anemia − − Clinical findings Digital clubbing, gynecomastia
Diabetic ketoacidosis[20] + +/− + − + ↓ Xerosis − Metabolic acidosis Ketonuria ↑Serum ketone, ↑ blood glucose − − Laboratory findings Dry mucous membranes, shock
Hypomagnesemia[21] + − − +/− − Normal − +/− Metabolic alkalosis − ↓Ca+2 − − Laboratory findings Trousseau and Chvostek signs
Burns[22] +/− − − + − ↓ Vesicle and bullae, erythema + Normal − Acute phase reactant − − Clinical findings Dehydration
Cystic fibrosis[23] +/− +/− − +/− − ↓ Early aquagenic skin wrinkling +/− Normal − − - Pulmonary infiltration Sweat chloride test Pancreatic insufficiency

Diagnostic Algorithm

Shown below is an algorithm depicting the possible laboratory findings and their interpretation.

 
 
 
 
 
 
Hypokalemia
[K+] < 3.5
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Order:
❑ 24 hours urinary K+ (UK)
❑ Transtubular potassium gradient (TTKG)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
UK > 25-30 mEq/L/day
TTKG > 7
 
UK < 25 mEq/L/day
TTKG < 3
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Renal loss of potassium
 
GI loss of potassium
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
What is the blood pressure?
 
Possible etiologies are:
Diarrhea
Laxatives
Villous adenoma
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Normal or ↓
 
 
 
 
 
 
 
 
 
↑
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Check the acid/base status
 
 
 
 
 
 
 
 
 
Possible etiologies are:
Primary aldosteronism
Secondary aldosteronism
Non aldosterone increase in mineralcorticoids
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Acidemia
 
Alkalemia
 
Variable
 
 
 
Order:
❑ Aldosterone
❑ Renin
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Check urinary chloride (UCl)
 
Hypomagnesemia
 
↑ Aldosterone
↓ Renin
 
↑ Aldosterone
↑ Renin
 
↓ Aldosterone
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
UCl < 20
 
UCl > 20
 
 
 
Primary aldosteronism
 
Secondary aldosteronism
 
Non aldosterone increase in mineralcorticoids
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Possible etiologies are:
Vomiting
Nasogastric tube
 
Possible etiologies are:
Diuretics
Bartter's
Gitelman's

Management

  • Treat the underlying etiology.
  • Potassium repletion for the deficit (for every 1 mEq/L decrease in potassium, there is 200 mEq loss of total body potassium):
    • PO: 40 mEq KCL Q 4-6 hours
    • IV (if urgent): 10 mEq/hour KCL
  • Recheck potassium levels in 2-4 hours.
  • Provide IV hydration if necessary.

Do's

  • Avoid excessive potassium repletion, particularly in the cases of transcellual shifts of potassium that can be reversed when the initial cause of hypokalemia is treated.
  • Treat low magnesium blood concentration.

Dont's

  • If hydration is needed, do not administer dextrose solutions because dextrose increases insulin which can causes intracellular shift of potassium, and further exacerbates hypokalemia.

References

  1. ↑ Bourke E, Delaney V (1994). "Prevention of hypokalemia caused by diuretics". Heart Dis Stroke. 3 (2): 63–7. PMID 8199766.
  2. ↑ Wu C, Xin J, Xin M, Zou H, Jing L, Zhu C; et al. (2016). "Hypokalemic myopathy in primary aldosteronism: A case report". Exp Ther Med. 12 (6): 4064–4066. doi:10.3892/etm.2016.3864. PMC 5228118. PMID 28101185.
  3. ↑ Torpy DJ, Mullen N, Ilias I, Nieman LK (September 2002). "Association of hypertension and hypokalemia with Cushing's syndrome caused by ectopic ACTH secretion: a series of 58 cases". Ann. N. Y. Acad. Sci. 970: 134–44. PMID 12381548.
  4. ↑ Choi HY, Ha SK (2013). "Potassium balances in maintenance hemodialysis". Electrolyte Blood Press. 11 (1): 9–16. doi:10.5049/EBP.2013.11.1.9. PMC 3741441. PMID 23946760.
  5. ↑ Hebert SC (September 2003). "Bartter syndrome". Curr. Opin. Nephrol. Hypertens. 12 (5): 527–32. doi:10.1097/01.mnh.0000088732.87142.43. PMID 12920401.
  6. ↑ Knoers NV, Levtchenko EN (2008). "Gitelman syndrome". Orphanet J Rare Dis. 3: 22. doi:10.1186/1750-1172-3-22. PMC 2518128. PMID 18667063.
  7. ↑ Tetti M, Monticone S, Burrello J, Matarazzo P, Veglio F, Pasini B, Jeunemaitre X, Mulatero P (March 2018). "Liddle Syndrome: Review of the Literature and Description of a New Case". Int J Mol Sci. 19 (3). doi:10.3390/ijms19030812. PMC 5877673. PMID 29534496.
  8. ↑ Asmar A, Mohandas R, Wingo CS (2012). "A physiologic-based approach to the treatment of a patient with hypokalemia". Am J Kidney Dis. 60 (3): 492–7. doi:10.1053/j.ajkd.2012.01.031. PMC 4776048. PMID 22901631.
  9. ↑ Cheungpasitporn W, Suksaranjit P, Chanprasert S (February 2012). "Pathophysiology of vomiting-induced hypokalemia and diagnostic approach". Am J Emerg Med. 30 (2): 384. doi:10.1016/j.ajem.2011.10.005. PMID 22169581.
  10. ↑ Bazerbachi F, Haffar S, Szarka LA, Wang Z, Prokop LJ, Murad MH, Camilleri M (November 2017). "Secretory diarrhea and hypokalemia associated with colonic pseudo-obstruction: A case study and systematic analysis of the literature". Neurogastroenterol. Motil. 29 (11). doi:10.1111/nmo.13120. PMID 28580600.
  11. ↑ Sanchez Garcia S, Villarejo Campos P, Manzanares Campillo Mdel C, Gil Rendo A, Muñoz Atienza V, García Santos EP; et al. (2013). "Hypersecretory villous adenoma as the primary cause of an intestinal intussusception and McKittrick-Wheelock syndrome". Can J Gastroenterol. 27 (11): 621–2. PMC 3816940. PMID 24199207.
  12. ↑ Krejs GJ (May 1987). "VIPoma syndrome". Am. J. Med. 82 (5B): 37–48. PMID 3035922.
  13. ↑ Gill M, McCauley M (2015). "Psychogenic polydipsia: the result, or cause of, deteriorating psychotic symptoms? A case report of the consequences of water intoxication". Case Rep Psychiatry. 2015: 846459. doi:10.1155/2015/846459. PMC 4320790. PMID 25688318.
  14. ↑ Nguyen FN, Kar JK, Verduzco-Gutierrez M, Zakaria A (2014). "A case of hypokalemic paralysis in a patient with neurogenic diabetes insipidus". Neurohospitalist. 4 (2): 90–3. doi:10.1177/1941874413495702. PMC 3975788. PMID 24707338.
  15. ↑ Rushing JM, Jones LE, Carney CP (2003). "Bulimia Nervosa: A Primary Care Review". Prim Care Companion J Clin Psychiatry. 5 (5): 217–224. PMC 419300. PMID 15213788.
  16. ↑ Liang CC, Yeh HC (2011). "Hypokalemic nephropathy in anorexia nervosa". CMAJ. 183 (11): E761. doi:10.1503/cmaj.101790. PMC 3153553. PMID 21670105.
  17. ↑ "Hypokalemic periodic paralysis | Genetic and Rare Diseases Information Center (GARD) – an NCATS Program".
  18. ↑ Zydlewski AW, Hasbargen JA (October 1998). "Hypothermia-induced hypokalemia". Mil Med. 163 (10): 719–21. PMID 9795553.
  19. ↑ Elisaf M, Liberopoulos E, Bairaktari E, Siamopoulos K (March 2002). "Hypokalaemia in alcoholic patients". Drug Alcohol Rev. 21 (1): 73–6. doi:10.1080/09595230220119282. PMID 12189007.
  20. ↑ Davis SM, Maddux AB, Alonso GT, Okada CR, Mourani PM, Maahs DM (2016). "Profound hypokalemia associated with severe diabetic ketoacidosis". Pediatr Diabetes. 17 (1): 61–5. doi:10.1111/pedi.12246. PMC 4896141. PMID 25430801.
  21. ↑ Huang CL, Kuo E (October 2007). "Mechanism of hypokalemia in magnesium deficiency". J. Am. Soc. Nephrol. 18 (10): 2649–52. doi:10.1681/ASN.2007070792. PMID 17804670.
  22. ↑ Nielson CB, Duethman NC, Howard JM, Moncure M, Wood JG (2017). "Burns: Pathophysiology of Systemic Complications and Current Management". J Burn Care Res. 38 (1): e469–e481. doi:10.1097/BCR.0000000000000355. PMC 5214064. PMID 27183443.
  23. ↑ Bates CM, Baum M, Quigley R (February 1997). "Cystic fibrosis presenting with hypokalemia and metabolic alkalosis in a previously healthy adolescent". J. Am. Soc. Nephrol. 8 (2): 352–5. PMID 9048354.
Retrieved from "https://www.wikidoc.org/index.php?title=Hypokalemia_resident_survival_guide&oldid=1486102"