3/4 - Sodium Disorders Flashcards
Normal Value for SODIUM
135 - 145 mEq / L
Primarily EXTRAcellular cation
Major Determinant of Plasma Osmolality:
2[Na] + Glucose/18 + BUN/2.8
Indications of HypoNatremia
Serum Sodium <135 mEq/L
Most commonly an EXCESS of Water vs Sodium
Hyper / hypo / isotonic
- *Non-Osmotic release of AVP**
- hypovolemia*, reduction in circulating volume, cirrhosis
- *SIADH**
MILD
Symptoms of HypoNatremia
< 135
None
Nausea / Malaise
MODERATE
Symptoms of HypoNatremia
< 120
HA / Lethargy
Restlessness / Disorientation
SEVERE
Symptoms of HypoNatremia
< 110
Seizure / Coma / Brain Dmg
Brain Stem Herniation / DEATH
CHRONIC HypoNatremia
CAN BE TOLERATED because of:
BRAIN ADAPTATION
Prevent SWELLING
Transport solutes EXTRAcellularly –> out
NaCl / K / Organic Solutes (glutamate / taurine / myo-inositol)
reduction in Brain Osmolality
induce water LOSS
Effect of RAPID SODIUM CORRECTION
on the BRAIN
Normal Brain & Normal Osmolality –> HypoTonic State
VVVV
Water Gain in Brain & low Osm –> RAPID ADAPTATION
VVVV
Loss of SODIUM / K / Cl & low osmolality
RAPID CORRECTION
VVVV
OSMOTIC DEMYELINATION
this is BAD, we need to correct the Sodium SLOWLY
HypoNatremia + HYPERtonic
Caused by what?
HYPERGLYCEMIA
or
Mannitol
Every ^100 mg/dL Glucose(serum) –> reduction of 1.7 mEq/L of Na
Increase of 100 mg/dL of Glucose
has what effect on Sodium?
↓1.7 mEq/L Na(serum)
HyperGlycemia / Mannitol
can cause:
HYPERtonic HypoNatremia
HypoNatremia + Isotonic
Caused by what?
PseudoHypoNatremia
HYPERlipidemia
HYPERproteinemia
HypoNatremia + HypoTonic
HYPERvolemic
Caused by what?
HYPERvolemic ↑ECF
CHF
Liver Failure
Nephrotic Syndrome
Acute/Chronic Renal Failure
HypoNatremia + HypoTonic
Euvolemic
Caused by what?
unchanged ECF
Euvolemic
HypoThyroidism
Addison’s Disease
SIADH
(Syndrome of Anappropriate ADH)
Causes of:
SIADH
Syndrome of Antidiuretic Hormone
- *CNS Disorders**
- *Stroke** / Mass Lesions
- *Trauma** / Acute Psychosis
Malignancy (Lung) // Infections / HIV
Pain / Severe Nausea
- *Medications**
- *Haloperidol** / Chlorpropamide / Carbamazepine
- *TCA / SSRI / Desmopressin**
Medications that can cause
SIADH
Syndrome of Inappropriate Antidiuretic Hormone
VV
Euvolemic HypoTonic HypoNatremia
TCA // SSRI
CARBAMAZEPINE
Chlorpropamide
DESMOPRESSIN
Haloperidol
HypoVolemic + HypoTonic + HypoNatremia
Caused by what?
Decreased ECF
- *RENAL LOSS**
- Cerebral Salt Wasting** / excessive Diuresis / Adrenal *Insufficiency
- NON-Renal Loss*
- *Bleeding / Vomiting / Diarrhea / Burns / Wounds / Sweating**
Acute / Severe Symptoms of HypoNatremia
HOW TO TREAT?
<48 hours & <110 mEq/L
Seizure / Coma / Brain Dmg
Brain Stem Herniation
3% NaCl , 1-2 mEq/L/Hr
with a SERUM SODIUM GOAL + TIMEFRAME
<125-130 mEq /l + monitor every 2-4 hours
HYPERnatremia is a SERIOUS issue
DO NOT EXCEED 8 mEq/L/DAY
vvv
Once stable –> treat underlying etiology
Chronic / Mild Symptoms of HypoNatremia
HOW TO TREAT?
>48 hours & <135 mEq/L + Symptomatic
Nausea / Malaise
Moderate <120
HA / Lethargy / Restlessness / Disorientation
0.9% NaCl or LR @ 0.5 mEq/L/Hr
with a SERUM SODIUM GOAL + TIMEFRAME
<125-130 mEq /l + monitor every 2-4 hours
HYPERnatremia is a SERIOUS issue
DO NOT EXCEED 8 mEq / L / DAY!
Calculating:
Change in Serum Na+ per 1L of Infusate
Management of HypoNatremia
- ( Infusate Na+** **- Serum Na*+** )
- *( TBW* + 1 )**
TBW = X(weight in kg)
Male X = 0.6 // Female X = 0.5
Elderly = 0.5 // 0.45
Maximum Increase in Serum Na+?
Goal Serum Na+?
8 mEq/L/ DAY
or risk for CPM = Central Pontine Myelinosis (osmotic demyelination)
from correcting hyponatremia too fast (>12 mEq/L/day)
125-130 mEq/l or lower
&
Monitor Na+ Q2-4 hours
What is CPM?
Central Pontine Myelinolysis
Loss of OLIGODENDROCYTES & MYELIN in the PONS
associated with:
TOO FAST of a correction rate of HypoNatremia = >12 mEq/L/day
Severity = <120 mEq/L
Chronicity = >48 hours
(Osmotic Demyelination)
Clinical Manifestations & @Risk Population of
CPM
Central Pontine Myelinolysis
Dysarthria / Dysphagia / Quadraplegia
Speech / Swallow / 4limb paralysis
Seizure / Coma / Death
@Risk Population:
Hepatic Failure / HypoKalemia / Malnutrition
(Alcoholics + malnutrition)
- *TREATMENT** for
- *HYPERvolemic** + HypoTonic + HypoNatremia
Caused by:
CHF / Liver Failure
Nephronic Syndrome / Acute+Chronic Renal Failure
Treat the UNDERLYING Cause
Na Restriction
Loop Diuretics
Furosamide / Bumetanide
Conivaptan // Tolvaptan
not used too often, shouldnt be used for LONG
Vasopressin Receptor Antagonist
Conivaptan // Tolvaptan
Use / Drug Type / MoA
for HYPERVolemic or Euvolemic
HypoTonic HypoNatremia
VASOPRESSIN RECEPTOR ANTAGONIST
inhibits AVP
(AVP normally would INCREASE REABSORPTION)
VVVV
Inhibit Reabsorption
VVVV
Diuresis / Reduction in Sodium
Side effects : HypoTension / HypoKalemia / HypoVolemia
- *TREATMENT** of
- *Euvolemic** HypoTonic HypoNatremia
Caused by:
HypoThyroidism // Addison’s Disease
SIADH
Mild-Moderate Symptoms (<135)
- *FLUID RESTRICTION**, stop the free water
- *Convivaptan / Tolvaptan**
- *Furosemide** + NaCl tab or 0.9% NaCl
_SEVERE SYMPTOMS_ (\<120) **Furosemide + 3% NaCl**
Treatment of CHRONIC SIADH
Which causes:
Euvolemic HypoTonic HypoNatremia
DEMECLOCYCLINE
Inhibits Renal Response to ADH
via cAMP inhibition
300-600 mg PO BID, 1hr ac or 2hr pc
2-5 day onset
Lithium / Phenytoin
2nd line because their response is unpredictable
& ADR’s
- *TREATMENT** of
- *HypoVolemic** HypoTonic HypoNatremia
Causes:
Renal Loss - cereb salt wasting / diuresis / adrenal insufficiency
Non-Renal Loss - bleed/ NVD / wounds / sweat
Mild-Moderate Symptoms (symptoms & <135)
NaCl Tablet + 0.9% NaCl
_SEVERE Symptoms_ (\<110 + s/sx) **3% NaCl**
Indications for HYPERnatremia
Serum Sodium >145 mEq / L
HYPERnatremia is a:
HYPERosmolar State ALWAYS = HYPERtonic always
Usually a TBW deficit
MODERATE HYPERnatremia
S/sx
Most symptoms are CNS Manifestations
- may also see* Intense THIRST, since HIGH Osm –> THIRST
- issue with MENTAL issues & infants, no brian mech for THIRST*
>145 mEq / L
MUSCLE WEAKNESS
RESTLESSNESS
NAUSEA / VOMITING
SEVERE HYPERnatremia
S/Sx
>160 mEq / L
CNS Manifestations:
Intense THIRST
Confusion
Lethargy
Irritabilty / Stupor
COMA
HYPERvolemia HYPERnatremia
Caused By?
Iatrogenic = Caused by Medical exam/treatment
3% NaCl
Excessive Na Ingestion // Hypertonic Dialysis
Antibiotics containing Na:
-CILLINS // Cephalosporins // Carbapenem
HYPERaldosteronism
Cushing’s Syndrome
Euvolemia HYPERnatremia
Caused By?
- Non-Renal Loss*
- *Fever**
- *HYPERventilation**
Renal Loss
DIABETES INSIPIDUS
Central DI vs Nephrogenic DI
PolyUria / PolyDipsia
USG < 1.005
(Urine Specific Gravity, normal = 1.010)
CENTRAL DI
Define & What can it cause?
Lack of Production/release of AVP
ECF is Normal due to thirst mechanism
From:
Head Trauma / Surgery (pituitary)
Phenytoin / EtOH
Diabetes Insipidus
VVV
EUVOLEMIC HYPERNATREMIA
Nephrogenic DI
Define & What can it cause?
Lack of RESPONSE by AVP
From:
Renal Disease // ↑Ca2+ // ↓ K+
Drugs:
Lithium / Democlocycline (treatment for SIADH -> HypoNatremia)
Amphoteracin B / Foscarnet / CLOZAPINE / CIMETIDINE
Nephrogenic Diabetes Insipidus
VVVV
Euvolemic HYPERnatremia
HypoVolemia + HYPERnatremia
Caused by what?
Renal Loss
Osmotic Diuresis // LOOP DIURETIC
Acute+Chronic Renal Disease
Non-Renal Loss
Diarrhea / Vomiting
Fistulas
Burns / Excessive Sweating
Rapid Sodium DECREASE
leads to WHAT?
Water Loss = High Osm Brain
VVV
RAPID CORRECTION of HYPERTONIC STATE
Accumulation of Organic Osmolytes in brain
VVV
CEREBRAL EDEMA
- *TREATMENT** for ACUTE + SEVERE
- *HYPERnatremia**
<48 hours + Symptoms:
Confusion / Lethargy / Coma / Irritability Stupor
> 160
You would only treat ACUTE if you KNOW that it is acute
from being in a hospital
D5W
@ 1-2 mEq/L/hr
To prevent OVERCORRECTION:
goal sodium is 145-150 mEq/L
Maximum decrease is: 10 mEq/L/ DAY
monitor Na Q2-4hours
- *TREATMENT** for Chronic + Mild
- *HYPERnatremia**
>48 hours + >145 mEq / L
Moderate Symptoms:
Muscle Weakness / Restlessness / N+V
You would only treat ACUTE if you KNOW that it is acute
from being in a hospital
D5W or 0.45%NaCl
@ 0.5 mEq/L/hr
To prevent OVERCORRECTION:
goal sodium is 145-150 mEq/L
Maximum decrease is: 10 mEq/L/ DAY
monotor Na Q2-4hours
What FLUIDS used to treat
HypoNatremia?
Change in Serum Na+ per 1L of infusate =
( Infusate Na+ - Serum Na+ )
( TBW* + 1 )
3% NaCl
MOST POTENT HYPERtonic Solution
513 Infusate Na+ & 100%+ ECF distribution
- *0.9% NaCl**
- *154** Infusate Na+ & 100% ECF distribution
- *LR**
- *130 Infusate Na+** & 97% ECF distribution
What FLUIDS used for:
HYPERnatremia
D5W
is the MOST POTENT due to No Sodium & HypoTonicity
0 Infusate Na+ & 40% ECF Distribution
- *0.45% NaCl**
- *77 Infusate Na+ & 40**
Change in Serum Na+ per 1L of infusate =
( Infusate Na+ - Serum Na+ )
( TBW* + 1 )
Free Water Deficit
Calculation
TBW Deficit = Normal TBW + Current TBW
Normal TBW = BW x %water
Current TBW = 140 / serum Na** x **Normal TBW
Normal TBW x (1 - [140/Naserum ])
Replace 1/2 Deficit over the 1st 24hours
VVV
Replace the other half over the next 24-72 hours
- *TREATMENT** for:
- *HYPERvolemia** + HYPERnatremia
Caused by:
Iatrogenics: 3% NaCl / Antibiotics / Excessive Na
HYPERaldosteronism
Cushing’s Syndrome
- *DISCONTINUE_ _offending agent**
ex. 3% NaCl
Diuretics
to elim. Na/H2O excess
- Hemodialysis*
- IF RENAL FAILURE, no diuretics in renal failure*
Replace Free Water Deficit
TBW Deficit = Normal TBW x (1 - [140/Naserum])
1/2 deficit over 24hr –> remaining 1/2 over 24-72hr
- *TREATMENT** for:
- *Euvolemia** + HYPERnatremia
Caused by:
Renal Loss = Central or Neurogenic Diabetes Insipidus
Non-Renal Loss = Fever / HYPERventilation
Mild-Moderate Symptoms
Replace Free Water Deficit PO or IV
TBW Deficit = Normal TBW x (1 - [140/Naserum])
1/2 deficit over 24hr –> remaining 1/2 over 24-72hr
SEVERE SYMPTOMS
Replace Free Water Deficit with D5W > 0.45% NaCl IV
For CDI: VASOPRESSIN / DESMOPRESSIN
For NDI: HCTZ / AMILORIDE / Indomethacin
- *TREATMENT** for:
- *Euvolemia** + HYPERnatremia
Caused by:
CENTRAL DIABETES INSIPIDUS
DESMOPRESSIN
First line due to Greater Potency & less smooth muscle effects
Longer Duration of Action & Dosage Forms
Nasal / Rhinal Tube / IV / Oral
Aqeuous Vasopressin
Only for initial Tx b/c short duration
& Side effects = Smooth muscle contractions
only IV or SC
Desmopressin
Used for / ADR / Etc
- *CENTRAL DIABETES INSIPIDUS**
- -> Euvolemia HYPERnatremia
- *Dosage forms are NOT bioequivelant**, need to convert doses
- *Greater Potency / Duration // less smoothmuscle ADR**
Nasal Spray = 0.1 mg/mL
10-40 mcg/D, QD or TID
Rhinal Tube
dose similar to nasal spray
IV = 4mcg / ml *NOTE mcg
2-4 mcg/d IV or SC BID
- *Oral = 0.1mg or 0.2mg tab**
0. 1 - 0.8 mg daily (BID or TID)
Aqueous Vasopressin
CENTRAL DIABETES INSIPIDUS
Euvolemic HYPERnatremia
Second line, only for Initial Treatment due to SHORT DURATION
<30 min onset –> 3-6 hours
IM or SC
NEGATIVES:
HYPERSENSITIVITY to BOVINE / PORCINE
Fluid Overload
SMOOTH MUSCLE CONTRACTIONS
Ab pain / Nausea / HTN / Angina / Uterine Contractions
- *TREATMENT** for
- *Euvolemic HYPERnatremia**
Caused by:
NEUROGENIC DIABETES INSIPIDUS
HCTZ
Thiazide diuretic, must be combined with Na Restriction
Paradoxical effect of ↓UOP by causing EC volume contraction –> proximal tube Na/H2O reabsorption ENHANCED
HypoKalemia / HYPERcalcemia
50-100mg qd or BID, effective in UOP decrease by 50%
Onset = 2-4 hours // DUration = 1-2 days
- *Amiloride**
- *K+ sparing diuretic, inhibit uptake of **Lithium in distal tubule
- mild HYPEKalemia*
Indomethacin
NSAID, blocks prostaglandin antagonism of AVP’s action
- *TREATMENT** for
- *HypoVolemia HYPERnatremia**
Causes:
Renal Loss = Osmotic diuresis / Loop Diuretic / Renal disease
Non-Renal Loss = Diarrhea / Vomit / Fistula / Sweat / burns
- *Mild-Moderate Symptoms**
- *Replace Free Water Deficit PO or IV**
SEVERE SYMPTOMS = hypovolemic SHOCK
0.9% NaCl 500-1000 mL
over 30-60 Min
still use 0.9% NaCl just to bring them OUT OF SHOCK
then:
Replace Free Water Deficit with 0.45% NaCl** or **D5W IV
Which ELECTROLYTE issue causes
SEIZURES?
HypoNatremia
Headache Lethargy Restlessness Disorientation
Coma
Brain damage Brain stem herniation
Death
When do you have to
REPLACE THE FREE WATER DEFICIT?
TBW Deficit = Normal TBW * (1 – [140/Naserum])
HYPERkalemia
All forms of Volemia.
1/2 deficit over 24 hours
Other half over next 24-72 hours