27.7.2013 Flashcards
Risk factors for developing central pontine myelinolysis
Hypokalemia
Malnutrition
Alcoholism
Correction of hyponatremia at a rate of more than 12mEq/L in a day
Presentation of central pontine myelinolysis
Flaccid paralysis
Dysarthria
Dysphagia
Initial allowable rate of correction of severe hyponatremia
1-2mEq/L/hr for first 3-4 hours
Change in Na+ from infusion of 1L of fluid
Na+i + k+i - Na+s/ TBW+1
TBW
Multiplying lean weight by 0.6 in men and 0.5 in women
Allowable rate of hyponatremia correction in chronic asymptomatic hyponatremia
5-8mEq/L in a 24 hr period
Drugs causing anterior ischemic optic neuropathy
Amiodarone
Interferon alpha
Dietary modifications in hyponatremia
High dietary solute load
High salt,high protein diet
Water restriction,calculations
Urine Na+ + K+/ serum Na+
Less than 0.5 1L/day
Btw 0.5-1 500ml/day
More than 1 indicates that all water is being reabsorbed
Most common GI cause of hypernatremia
Diarrhoea
Electrolyte disorders causing Nephrogenic diabetes insipidus
Hypokalemia
Hypercalcemia
Causes of Transcellular water shift from ECF to ICF
Rhabdomyolysis
Seizures
Urine osmolality in hypernatremia
More than 800 mosm/L
Urine osmolality in complete forms of CDI and NDI
Less than 300 mosm/L
Rate of correction of hypernatremia
10-12mEq/L/day
In chronic asymptomatic hypernatremia- 5-8 mEq/L/day
