1. MANAGEMENT OF DISORDERS OF SODIUM
Prof.S.SHIVAKUMAR’S UNIT
Dr.MADHU SHANKAR.G

2. DYSNATREMIA Normal values 135-145 mEq/L.
Disorder primarily of water balance which manifests as hypo/hypernatremia.
Accompanied by various component of negative solute balance.
Most common of the electrolyte disorders encountered in clinical practice.
Major cation of ECF.

3. Total body Na determines ECF Volume(Interstitial & intravascular).
Ratio of Na to Water determines plasma osmolality(inturn ICF volume).
Plasma Osmolality = 2*Na + Glucose/18 + Urea/6
2*Na + 10

4. OSMOREGULATION VOLUME REGULATION Hypothalamic osmoreceptors
Plasme osmolality
ADH & thirst
Water intake & excretion
VOLUME REGULATION
Carotid sinus,atria,Aff arteriole
Effective circulating volume
RAAS,Sympathetic nervous sys,ANP & Urodilantin
Urinary Na excretion

5. HYPONATREMIA(<135) True or pseudohyponatremia Serum Osmalality
Urine Osmalality
ECF volume
Urinary Na

6. HYPONATREMIA PLASMA OSMOLALITY 2*Na+Glucose/18+Urea/6
APPROACH TO DIAGNOSIS
HYPONATREMIA PLASMA OSMOLALITY 2*Na+Glucose/18+Urea/6

7. Plasma osmolality high normal LOW 1. Hyperglycemia 1
Plasma osmolality high normal LOW 1.Hyperglycemia 1.Hyperproteinemia 2.I.V.Mannitol 2.Hyperlipidemia 3.TURP For every 100mg/dl rise in plasma glucose,Na value drops by 1.6mEq/L

8. APPROACH TO DIAGNOSIS
HYPONATREMIA PLASMA OSMOLALITY 2*Na+Glucose/18+Urea/6 URINARY OSMOLALITY

9. Plasma osmolality high normal LOW 1. Hyperglycemia 1
Plasma osmolality high normal LOW 1.Hyperglycemia 1.Hyperproteinemia 2.I.V.Mannitol 2.Hyperlipidemia 3.TURP Urine osmolality >100 mosm/kg <100 1.Primarypolydipsia 2.Reset osmostat

10. APPROACH TO DIAGNOSIS
HYPONATREMIA PLASMA OSMOLALITY 2*Na+Glucose/18+Urea/6 URINARY OSMOLALITY ECF VOLUME

11. Hypovolemic Euvolemic Hypervolemic
Plasma osmolality
high normal LOW
1.Hyperglycemia 1.Hyperproteinemia
2.I.V.Mannitol 2.Hyperlipidemia
3.TURP Urine osmolality
>100 mosm/kg <100
ECF volume Primary polydipsia
2.Reset osmostat
Hypovolemic Euvolemic Hypervolemic
TBW TBW TBW
TB Na TB Na TB Na

12. APPROACH TO DIAGNOSIS
HYPONATREMIA PLASMA OSMOLALITY 2*Na+Glucose/18+Urea/6 URINARY OSMOLALITY ECF VOLUME URINARY Na

13. Contd…
Hypovolemic Euvolemic Hypervolemic U Na>20 U Na<10 U Na>20 U Na>20 Diuretic-Thiazide Vomitting SIADH Heart failure Osmotic diuretic Diarrhoea Hypothyroidism Liver cirrhosis Salt losing nephritis Third space Glucocorticoid Nephrotic syndrome Mineralocorticoid losses deficiency Renal insufficiency deficiency Burns Pancreatitis Bicarbonaturia RTA Vomitting

14. Hyponatremia (ICF ) 45 % 20% Eg: SIADH
INTRACELLULAR
PNa+
20%
Eg: SIADH
Increased ADH Increased total body H2O leads to decreased plasma Na ( Osmolarity ) Increased ICF due to shift of H2O from ECF to ICF.

15. Hypernatremia (ICF ) 20% 30% PNa Eg: D.Insipidus
INTRACELLULAR
Eg: D.Insipidus
Polyuria Pure water depletion Decreased body H2O leads to increased plasma Na ( Osmolarity)
H2O shifts from ICF to ECF.

16. Volume depletion & Hyponatremia (ECF & ICF )
45 %
Hypotension, skin turgor loss, Drowsiness
INTRACELLULAR
H2O
PNa
10 %
Na +
Eg: Diarrhea, replaced by 5 % GDW
Total body Na decreased by Diarrhea
Increasaed H2O retention due to 5 % GDW ( Plasma Na low)
ECF volume depletion + Increased ICF volume

17. Volume excess & Hyponatremia ( ECF & ICF )
25 %
45 %
INTRACELLULAR
H2O
edema
& P Na +
Eg: Cirrhosis + 5 % GDW
Cirrhosis leads to increased total body Na & ECF
Excess H2O leads to decreased plasma Na & increased ICF

18. 30 % 10% Volume depletion & Hyperosmolarity ( ECF & ICF ) Osmolarity
INTRACELLULAR
Osmolarity
Na+
H2O
Eg: Hyperosmolar Non- Ketotic syndrome ( DM)
Polyuria of DM leads to ECF volume depletion ( H2O> Na)
Increased plasma Glucose leads to hyperosmolarity & ICF depletion
Plasma Na can be Normal OR High ( Instead of being low)

19. PRESENTATION Normal values 135 – 145 mEq/L Hyponatremia <135 mEq/L
Mild
Moderate
Severe <

20. MANIFESTATION Asymptomatic Symptomatic-Pred.NEUROLOGICAL
<125-Nonspecific GI complaints,nausea,
malaise
<120-Headache,lethargy,obtundation
< Seizures,coma
Focal deficit uncommon

21. CEREBRAL ADAPTATION Subsequently after 3 hrs Initial 3 hrs
plasma osmolality  ICF volume  interstitial pressure
shunting of ECFCSFcirculation.
Subsequently after 3 hrs
reduction in intracellular solutes(potassium)
Ensuing 72 hrs
loss of intracellular osmolytes viz glutamine,glutamate,
taurine,myo-inositol

22. CEREBRAL ADAPTATION BOON OR BANE……
CEREBRAL ADAPTATION BOON OR BANE……. CENTRAL PONTINE MYELINOLYSIS OSMOTIC DEMYELINATION SYNDROME

23. AT RISK Postop menstruating women On thiazides Alcoholics Malnourished
Hypokalemic patients
SEVERITY AND CHRONICITY
<120 mEq/L
>48 hrs

24. MANAGEMENT Presence or absence of symptoms Severity Chronicity
Volume status

25. OPTIONS Masterly inactivity Volume correction Water restriction
Infusion of hypertonic saline

26. Body wt*0.6(Desired Na – calculated Na)
Hyponatremia
Asymptomatic
Chronic ( > 48 hrs)
Symptomatic
Chronic > 48 hrs
Body wt*0.6(Desired Na – calculated Na)
Acute < 48 hrs

27. Management Symptomatic Hyponatremia
Treatment: Emergency: 3 % NaCl ml/ kg/ hr with co-administration of Furosemide
STRATEGY: Removal of H2O
Furosemide: Natriuresis -- Na + H2O
Replace Na with 3 % NaCl – Excretion of H2O
Urine output > fluid intake

28. Hypovolemic Hyponatremia:
Asymptomatic Hyponatremia: ( Euvolemia& Hypervolemia)
1.Water restriction : < 1L / day
2.Demeclocycline – 600 mg / day
3.Identify & treat the causes
Hypovolemic Hyponatremia:
IV Fluids -- NaCl / RL
Hypervolemic Hyponatremia:
Water and Salt restriction
Diuretics
Treat the cause

29. GUIDELINES Acute hyponatremia(<48 hrs)
Raise Na rapidly by approx 2 mEq/L/hr until symptoms resolve
Max correction 15 mEq/L/day
Chronic(>48 hrs)
Prompt increase by 10% or 10 mEq/L
Max correction 1.5mEq/L/hr or 15mEq/l/day
Serial neurological examination
Measure serum and urine electrolytes 1-2 hrly

30. HYPERNATREMIA Plasma Na >145mEq/L
Reflects a state of Hyperosmolality

31. HYPERNATREMIA Hypovolemic Euvolemic Hypervolemic TBW TBW TBW TB Na TB Na TB Na Diuretics loop/osmotic Diabetes insipidus Hypertonic PD Excess insensible water loss Hypodipsia Cushings GI loss diarrhea,fistula Conn’s syn Diuretic phase of ATN

32. MANIFESTATION Values >145 mEq/L Pred Neurological Hyperreflexia
Damage to intravascular structures

33. REPLACE THE EXISTING LOSS AND ONGOING DEFICIT
PRINCIPLES
Recognition
Identifying the cause
Correcting volume disturbances
REPLACE THE EXISTING LOSS AND ONGOING DEFICIT
Body wt*0.6(P Na/140 – 1)

34. Treatment: Hypovolemic Hypernatremia : -- isotonic saline
% NaCl
-- 5 % GDW
-- Oral fluids
Euvolemic Hypernatremia: 5 % GDW Oral fluids
Hypervolemic Hypernatremia: Dialysis

35. GUIDELINES Correct at a rate of 2 mEq/L/hr
Replace half the water deficit over 24 hrs
Replace the remaining over next 24 hrs
Perform serial neurological examination
Measure serum and urine electrolytes every 1-2 hrs

36. TAKE HOME
Dysnatremias are primary disorders of water balance,with variable component of negetive solute balance
Prompt recognition
Dont do overzealous correction
Identify and treat the cause

37. THANK YOU