Fluid and electrolyt

1. Fluid and electrolyt

2. Basic physiology Water • largest single component of the body • Total body water approx 75% of body wt at birth. & decreases with age. • TBW – divided into 2 main compartments a, ICF (30-40%) b, ECF (20-25%) –plasma (5%) - interstitial (15%) * transcellular (2%)- GI secretions, urine, CSF, pleural, peritonial, synovial

3. Age & TBW

4. Basic physiology • Plasma Osmolality –concn of solute particles in plasma – 285-295mosm/kg/H2O • H2O is distributed b/w ICF & ECF according to amount of osmotically active solute in each compartment. • ECF solutes- Na+,Cl-,HCO3, glucose & urea • ICF solute - mainly K+ • Other solutes-ethanol, mannitol,glycerol may contribute to an extent to plasma osmolality • * At steady state- -Osmolality of ICF= ECF = Plasma

5. Body water osmolality • Normal osmolality = 285 – 295 mOsm/kg • Change in ECF osmolality leads to change in ICF osmolality • Calculated from E&u and glucose conc. • 2xNa + Glucose (mmol/L) + Urea (mmol/L) • Glu m/dl ÷ 18 = glummo/L • Urea mg/dl ÷ 2.8 = urea mmol/L • Calculated value usually slightly less than measured value

6. What is the plasma osmolality • Na = 140 mmol/L • Cl = 102 mmol/L • K = 4.6 mmol/L • Urea = 30 mg/dl • BGL = 80 mg/dl

7. answer • 295 mOsm/kg • Urea produces “in-effective” osmolality since it diffuses freely across the cell membrane

8. What is the osmolality? • 4.3% dextrose / 0.18% saline • Answer • Dextrose = 4300mg ÷ 18 = 237 mmol/L • Sodium = 0.9 (154mmol) ÷ 5 = 30.8mmol x 2 = 62 • Answer = 299 mmol/kg

9. Maintenance fluid

10. Adjustments in maintenance fluid

11. The commonest indication for fluid therapy in children is Diarrhea. Diarrheal diseases contribute 19% under-five deaths in developing countries and 65% diarrheal deaths are attributable to dehydration • Fluid therapies in children require careful planning, administration and monitoring as complications, some of which may be fatal, may complicate careless fluid therapy.

12. DETERMINATION OF REQUIREMENTS Fluid Requirements are categorized into 3: • Maintenance fluid requirement • Replacement of deficits: • Supplemental fluid therapy: • Replaces ongoing losses of fluids and electrolytes • Administered in addition to the maintenance and deficit fluid replacement therapies

14. Electrolyte content of ivf

15. Mode of fluid therapy • Oral fluid therapy • Parenteral fluid therapy • Others intraosseous

16. Types of dehydration Classification based on: • Fluid volume depletion-Mild, Moderate and Severe dehydrations • Plasma tonicity [osmolality]-Hypotonic, Isotonic and hypertonic dehydrations • Sodium conc: Hyponatraemic, Isonatraemic and Hypernatraemic dehydrations

17. Isotonic dehydration • Commonly caused by diarrhoea • Net losses of water and sodium are in the same proportion as normally found in the Extracellular fluid • Features- • Balanced deficit of water and sodium • Serum sodium concentration is normal[130-150mmol/l • Serum osmolality is normal[275-295 mOsmol/l • Hypovolaemia occurs as a result of a substantial loss of ECF • Signs appear when losses exceed 5% body wt and worsen with increasing losses

18. Hypertonic dehydration • Results from ingestion of fluids with high sodium or electrolyte content with poor intake of water or other hypo-osmolar fluids and poor absorption of the administered fluids. There is osmotic diarrhoea with loss of fluid from ECF • Features: • There is deficit of water and sodium, but the deficit of water is greater • Serum sodium concentration is elevated[>150 mmol/l]; • Serum osmolality is elevated[> 295mOsmol/l] • Thirst is severe and out of proportion to the apparent degree of dehydration; the child is very irritable; • Seizures may occur, especially when serum sodium concentration exceeds 165 mmol/l

19. Hypotonic dehydration • Results from intake of water or fluids with low solute content e.g. Dextrose infusions. The water is absorbed while sodium loss continues • Features • There is deficit of water and sodium but the deficit of sodium is greater • Serum sodium concentration is low-<130mmol/l • Serum osmolality is low-<275 mOsmol/l • The child is lethargic and infrequently may have seizures

20. Hypernatremic dehydration • This is the most dangerous form of dehydration due to complication of hypernatremia and of therapy. • Brain haemorrhage is the most devastating consequence of hypernatremia, other complications of hypernatremia include; thrombosis, central pontine myelinosis, extrapontine myelinosis. • Hypernatremia may cause fever, hyperglycaemia and mild hypocalcaemia

21. pathophysiology • Increase in ECF osmolality movement of water out of the brain cells • decrease brain volume tearing of intracerebral veins and bridging blood vessels Brain haemorrhage seizures and coma

22. Pathophysiology therapy • Rapid treatment of hypernatremia may cause significant morbidity and mortality • Idiogenic osmoles are generated within the brain during the development of hypernatremia. • They increases the osmolality within the brain, providing protection against brain shrinkage caused by the movement of water out of the brain cell into the hypertonic ECF. • Idiogenic osmoles dissipate slowly during correction of hypernatraemia • Rapid lowering of the ECF during correction causes water movement from the ECF into the brain, producing cerebral oedema

23. Pathophysiology-therapy

24. Treament of hypernatremic dehydration • 5% dextrose in half normal saline. • Correction is over 48-72hrs or more depending on the serum level of sodium

25. Hyperkalaemia and hypok • What are the ECG features and correction moderlaities

27. What is the sign