Normal Ionized calcium levels
4.5 to 5.5 mg/dL
Normal phosphorus leve
2.8 to 4.5mg/dL
normal magnesium
1.3 to 2.2mEq/dL
Most cases of hypermagnesium are due to..
other cuases inclued
Mg greater than 2.2mEq/L are iatrogenic causes
DKA, Theophylline poison, kidney failure
signs and symptoms of hyperMagnesemia include
weakness, fatigue, respiratory failure, cardiac failure, hypotension, tendor hyporeflexes
Mg levels of > 5-10 can cause what on ECG
prolonged QT, QRS, PR
Treatment for hypermagnesemia
normal saline for renal excreation
calcium gluconate,
dialysis,
Hypomagnesemia most common cause is
Mg < 1.3mEq/L commonly impaired digestion and proton pump inhibitors alcohol vomit/diarrhea nasogastric aspiration
renal over excretion osmotic diuresis resoving acute tubular necrosis loop diuretics bartter and Gitleman syndrome
drugs that cause hypomagnesemia include
aminoglycosides, cyclosporin
Signs and symptoms of hypomagnesemia
lethargy confusion, tremor fasciculations ataxia nystagmus, tetany seizures arrhythmias ( especially with digoxin
diagnostic signs of hypomagnesemia
low K and Ca
urine magniesium excreation >24mg
ECG torsades de pointes**
treatment of hypomagnesemia in patient with renal failre
slow and low administration of magnesium administration with frequent checks
Treatment of asymptomatic mild hypomagnesemia (<1.3mEq/L), what to watch for»
240mg daily (MagOx 240mg, UroMg 84mg, SlowMg 64mg)
Watch for diarrhea and reflexes
Fluid shifts may be deceving
Treatment of asymptomatic severe hypomagnesemia (<1.3mEq/L), what to watch for»
720mg daily
watch for diarrhea, hyporeflexes
fluid shifts may be deceiving
Treatment of symptomatic severe hypomagnesemia (<1.3mEq/L), what to watch for»
1-2g Mg sulfate IV over 15minutes for 3-7 days maintain Mg level below 2.5mEq/L
watch for hyporeflexia
treatslow too fast leads to kidney excretion
normal Anion Gap is
10 (+or - 2) mEq
normal HCO3 is
24(+or-) 2 mEq/L
normal CL levels
97 to 107 mEq/L
PCO2 normal levels are
40 (+or-5) mEq/L
causes of metabolic acidosis
ketoacids methanol, ethylene glycol, salicylates lactic acid (shock, drugs) profound uremia Non-gaP diarrhea (nonrenal hco3 los) renal bicarb los decrease H secreation hypoaldosteronism
metabolic acidosis is characterized by
decrease plasma HCO3 due to HCO3 loss or acucumlation of acid
eleveated AG mean metabolic acidosis
metabolic alkalosis characterized by
elevation in plasma HCO3 due to H+ loss or HCO3 gain
respiratory acidosis characterized by
elevation of pCO2 from hypoventalation
respiratory alkalosis characterized by
decrease pCO2 from hyperventilation
Diagnosis of acid base balance
Step1: check arterial blood gas step2; distinguish whether it was a change in PCO2 or HCO3 Step3: determine in compensattion step 4: determine anion gap step 5: asses delta gap
proxima type 2 Rta caused by
impaired proximal tube absorption
serum k low
Distal type 1 RTA cause by
impaired H Secreation hypercalcium autoimmune renal disorder amphotericin B
Distal Type 4 RTA (hyperkalemia) cause by
low aldosterone diabetes nSAIDS bblockers cyclosporin
treatment of metabolic acidosis ketoacidosis
treated the cause etoh, starvation, or dka
treatement of metabolic acidosis lactic acidosis
resove underlying cause
watch for rebound alkalosis
treatment of RTA type 1
oral HCO3
Can NaHCO3 be used to correct respiratory acidosis
NO
paradoxical worsens the ph and will increase the pCO2 causing hypercapnic situation
Gold standard for assessment of daily electrolyte excreation
24 hour urine collection
Explain fractional excretion
can be used in place of 24 hour urine collection for faster results
low fraction mean high avidity or electroly retention
high fraction mean low avidity or electrolyte wasting
What is tonicity
osmolytes that are impermeable to cell membranes
what is essential in determining etiology of hyponatrememia
volume status and serum osmolality
hypotonic fluids can cause sodium to
decrease
low serum osmolality would be
<280 mOsm/kg
Hyponatremia with low serum osmolality (<280 mOsm/kg) with euvolemic volume status could be due to
- SIADH
- post operative hyponatremeia
- hypothyroidism
- . psychogenic polydipsism
- beer potomania
- idiosyncritic drug reactio
- endurance exercise
- adrenocorticotropin deficiency
Hyponatremia with low serum osmolality (<280 mOsm/kg) with hypovolemic volume status and Uring Na of <10mEq/L (extrarenal loss) could be due to
1) dehydration
2. diarrhea
3. vomiting
Hyponatremia with low serum osmolality (<280 mOsm/kg) with hypovolemic volume status and Uring Na of >20mEq/L (renal loss) could be due to
- diuretics
- ACE inhibitor
- Nephropatheis
- mineralocorticoid deficiency
- cerebral sodium wasting syndrome
Hyponatremia with low serum osmolality (<280 mOsm/kg) with hypervolemic volume status could be due to
Edematous states
- heart failure
- liver disease
- nephrotic syndrome
- advanced kidney disease
Hyponatremia with normal serum osmolality (280 to 295 mOsm/kg) could be due to
- hyper proteinemiea
2. hyperlipidemia
Hyponatremia with high serum osmolality (<295 mOsm/kg) could be due to
- hyperglycemia
- mannitol
- radiocontrast agents
most serious complication of hyponatremia
iatrogenic cerebral osmotic demyelination (central pontine myelonosis)
Treatment of Hyponatremia first step
limit free water intake, 1 to 1.5 L/day
Treatment of hypovolemic Hyponatremia
isotonic fluids
Treatment of hypovolemic cerebral salt wasting Hyponatremia
hypertonic solution and fludrocortisone
Treatment of hypervolemic Hyponatremia
diuretics, dialysis,
Treatment of euvolemic Hyponatremia
water restriction
Treatment of severe and symptomatic Hyponatremia
4-6 mEq/L
calculate sodium deifcite and give 3% saline
.25ml/kg/h
Treatment of severe and symptomatic acute Hyponatremia with neurologic manifestation
like exercise hyponatremia
100ml 3% saline over 1min
Treatment of severe and symptomatic chronic Hyponatremia
correction rates are low (like 6mEq/L over 24hr)
Treatment of severe and symptomatic chronic Hyponatremia corrected too rapidly
DDAVP and iv dextrose 5%
when should patient with hypvolemic hyponatremia be refered
servere symptomatic, refractory, or complicated hyponatremia,
aggressive therapy liek hypertonic sline demeclocycline, or vasopressin antagonist or dialysis mandate specialist
endstage liver or heart disease
when should patient with hyponatremia be admitted
sign and symptoms of severe hyponatremia
