1 / 18

Fluid, Electrolyte and Acid-Base Balance

Fluid, Electrolyte and Acid-Base Balance. Chapter 27 (26). Where’s the water?. Water content varies with age & tissue type. Infants – 73% Adult male – 60% Adult female – 50% Elderly – 45% Fat has the lowest water content (~20%). Bone is close behind (~22 – 25%).

ralph
Télécharger la présentation

Fluid, Electrolyte and Acid-Base Balance

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Fluid, Electrolyte and Acid-Base Balance Chapter 27 (26)

  2. Where’s the water?

  3. Water content varies with age & tissue type • Infants – 73% • Adult male – 60% • Adult female – 50% • Elderly – 45% Fat has the lowest water content (~20%). Bone is close behind (~22 – 25%). Skeletal muscle is highest at ~65%.

  4. Electrolyte concentrations are calculated in milliequivalents mEq/L = ion concentration (mg/L) x number of charges on one ion atomic weight Na+ concentration in the body is 3300 mg/L Na+ carries a single positive charge. Its atomic weight is approximately 23. Therefore, in a human the normal value for Na+ is: 3300 mg/L= 143 mEq/L 23 Note: One mEq of a univalent is equal to one mOsm whereas one mEq of a bivalent ion is equal to ½ mOsm. However, the reactivity of 1 mEq is equal to 1 mEq.

  5. Relative electrolyte concentrations:Plasma, Interstitial Fluid & ICF

  6. Sources of intake & output

  7. Regulation of water balance • It is not so much water that is regulated, but solutes. • osmolality is maintained at between 285 – 300 mOsm. • An increase above 300 mOsm triggers: • Thirst • Antidiuretic Hormone release

  8. The Thirst Mechanism An increase of 2 – 3% in plasma osmolality triggers the thirst center of the hypothalamus. Secondarily, a 10 – 15% drop in blood volume also triggers thirst. This is a significantly weaker stimulus.

  9. Dehydration • Chronic dehydration leads to oliguria. • Severe dehydration can result in hypovolemic shock. • Causes include: • Hemorrhage • Burns • Vomiting • Diarrhea • Sweating • Diuresis, which can be caused by diabetes insipidus, diabetes mellitus and hypertension (pressure diuresis).

  10. Hypotonic hydration • A severe drop in osmolality • Caused by: • Excessive water intake • Renal dysfunction • Major consequence is hyponatremia. • Hyponatremia results in: • Cerebral edema (brain swelling) • Sluggish neural activity • Convulsions, muscle spasms, deranged behavior. • Treated with I.V. hypertonic mannitol or something similar.

  11. A rather lame illustrationYou do remember how osmosis works, don’t you?

  12. Sodium regulation

  13. Blood pressure, sodium, and water

  14. Atrial Naturetic Peptide:The heart’s own compensatory mechanism.

  15. Buffers

  16. Reabsorption of bicarbonate

  17. Generation of new bicarbonate from phosphate

  18. Generation of bicarbonate from glutamine deamination

More Related