Hyponatremia and hypernatremia (3)
-
Upload
aseem-watts -
Category
Health & Medicine
-
view
112 -
download
3
Transcript of Hyponatremia and hypernatremia (3)
![Page 1: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/1.jpg)
HYPONATEREMIA AND HYPERNATREMIA
DR ASEEM WATTS
DNB INTERNAL MEDICINE
MODERATOR -DR MEGHNA KABRA
![Page 2: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/2.jpg)
TBW=2/3(ICF)+1/3(ECF)=0.6* LBW in Male,0.5*LBW in females ECF =INTRAVASCULAR(plasma water)+INTERSTITIAL(extravascular)
with ratio of 1:3 to 1:4 Normal plasma osmolality-275-290 mosmol/kg Maximal urine osmolality our kidney can attain -1200 mosmol/kg Minimal urine osmolality our kidney can attain-50 mosmol/kg
requiring 12ltr/day urine output. Minimum urine output required to excrete daily solute
load(amount of salt consumed per day i.e. Roughly 600 to 800 mOsm/day) is 600/1200=500ml/day.
General Principle
![Page 3: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/3.jpg)
Major ECF electrolyte =Sodium (85-90%) Change in sodium concentration reflects-disturbed water homeostasis .
Contd.
Water lost in stool=200ml/day and produced by metabolism=250-350 ml/day.
Insensible losses=400 to 500ml/day (increase by 100-150ml/day for each 1 degree C rise above 37 degree C.
![Page 4: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/4.jpg)
WATER BALANCE:-
Water intake-Thirst by Osmorecepotors with threshold >295mosm/kg, in anterolateral hypothalamus(ineffective osmoles like Urea-no role in thirst)
Water excretion-ADH with major stimulus for its secretion is hypertonicity with threshold of 280-290mosmol/kg Nonosmotic stimuli for ADH release-Arterial Effective circulating volume,nausia,pain,stress,hypoglycemia, Pregnancy,numerous drugs.
![Page 5: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/5.jpg)
SODIUM BALANCE :-
INTAKE:- In Western Diet 150 mmol of NaCl/Day normally exceeds basal requirements-ECF Volume expansion promotes enhanced Na+ excretion to maintain balance.
EXCRETION:-Multiple factors Change in effective circulatory volume ➡️ Parallel change in GFR Major regulator of Na+ is Tubular Na+ reabsorption. (2/3 approx absorbed electro neutrally and iso oosmotically in
PCT.) Rest 1/3 absorbed in Thick ascending Loop of Henle via apical
Na+K+2Cl- Co Transporter as an electro neutral active process. DCT reabsorption 5% mediated by thiazide sensitive Na+Cl-
Cotransporter. Final reabsorption in medullary and cortical CD.
![Page 6: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/6.jpg)
Na+<135meq/l (primarily water balance or distribution disorder.) Symptoms:- Primarily neurogenic- Related to Osmotic intracellular
water shift ➡️ Cerebral edema.
Severity
Acute condition(<2 Days) :- Nausea and Malaise with Na+125 <125-Headache,Lethargy,Confusion and Obtundation <115-Stupor,Seizures and coma
HYPONATREMIA
Magnitude of Hyponatremia
Rapidity of disease
![Page 7: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/7.jpg)
Contd.
Chronic condition(>3 days) :-Osmotic Adaptation tend to minimise the symptoms
Diagnosis:-History and Physical Examination for ECF Volume status and Effective ciculatory volume.
![Page 8: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/8.jpg)
Hyponatremia(Too much water not enough salt)
Check Serum Osmolality(Serum Osmolality =2[Na+]+Glucose/18+BUN/2.8)
Approx =2*[Na]+10
Hypo-osmolar
<280
Iso-osmolar280-295
(Pseudohypernatremia)
Hyperosmolar>295
![Page 9: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/9.jpg)
Iso osmolar/Pseudohyponatrmia:- Old lab Artifact Underestimate level when TG high,Protein high>10,
Hyper-osmolar:- Infact sodium is normal High Glucose/Mannitol dilutes Na+
Corrected Na for high Glucose=[Na+] +2.4 for each 100mg/dl increase in blood glucose.
Rx-Correct glucose
![Page 10: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/10.jpg)
Hypo-osmolar Hyponatremia(true Hyponatremia)
Assess Volume status Vitals:-BP,HR,Orthostatic
JVP-Overload Axillary Moisture Chest S4-Overload
Pulmonary-BiBasilar Crackles Pedal Edema
Lab:-Uric acid,BNP-<50,Specific gravity
Hypovolemic (High ADH) Euvolemic Hypervolemic
(High ADH)
![Page 11: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/11.jpg)
HYPOTHALAMUS
Posterior Pituitary
ADH
1. INCREASE IN OSMOLALITY(hypothalamus)2. DECREASE IN VOLUME(baroreceptor/Vagus)
➕
V1(Squeeze)V1a and V1b
V2 on P Cell of CD(GPCR)
Via adenyl cyclise Aquaporin 2
insertion into luminal surface.
At high concVasoconstriction
Induce glycogenolysisInc ACTH release
![Page 12: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/12.jpg)
Hypovolemic Hyposmolar Hyponatremia
Loss of salt more than water
Assess Renal Reaction(Urine Sodium)
Kidney got this UNa+ <10
Fault at kidney levelUNa+ >20
GI Loss-Diarrhea,Vomiting Skin loss-
Sweating,Burns,pancreatitis
Drugs-Ace inhibitors,Thiazide Other- Nephropathy,Mineralocorticoid
insufficiency,Bicarbonaturia, Ketonuria Cerebral salt wasting syndrome
(Including Head injury-increased ADH-Increased BNP-decreased Aldosterone.) also show refractory
hypotension
![Page 13: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/13.jpg)
Urinary osmolality
Euvolemic Hypo-osmolar Hyponatremia
<100 mOsm/L (Appropriate)
>100 mOsmol/l
(Inappropriate)
Primary Polydipsia Beer Protomania
Post-TURP
SIADH R/O Hypothyroidism
& Decreased Cortisol,drugs,stress
UNa+ >20meq/dlUrine Osmolality is low but higher than that of plasma
![Page 14: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/14.jpg)
SIADHCharacterised by hyponatremia caused by a sustained release of ADH
in absence of osmotic and non osmotic stimuli.
Diagnostic criteria are:-1. Hyponatremia2. ⬇ plasma Osmolality (<280 mosm/l)3. Inappropriately increased urine Osmolality (>100 mosm/dl)4. Urine sodium >20 meq/l (sodium excretion due to increase in ECF
occur because sympathetic nervous system,RAAS and Atrial natriuretic factor release are preserved)
5. Normal thyroid and adrenal functions
![Page 15: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/15.jpg)
![Page 16: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/16.jpg)
Urinary Osmolality low but higher than that of plasma
Low BUN and low serum Uric acid levels (because of dilution and increased clearance in personae to volume expanded state)
Glucocorticoids exert a negative feedback on AVP release by the posterior pituitary so that hydrocortisone replacement in these patients will rapidly normalize the AVP response to osmolality, reducing circulating AVP.
![Page 17: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/17.jpg)
HYPERVOLEMIC HYPO-OSMOLAR HYPONATREMIAFluid overall increase but in wrong space.
Body looks it as hypovolemic.
Assess Kidney function (kidney should be peeing a diluted urine[RAAS])
Urine Na+ <20meq/l
Kidney working fine CHF(Dec Renal Perfusion)
Liver Cirrhosis (Dec Intravascular volume +Splanchnic Vasodilation)
Nephrotic Syndrome
Urine Na+ >20meq/l
Renal Insufficiency Renal Failure
Rx-Loop Diuretics.In Liver failure Spironolactone / Octreotide
![Page 18: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/18.jpg)
![Page 19: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/19.jpg)
![Page 20: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/20.jpg)
TREATMENT
Issues:- 1. Rate of correction2. The appropriate intervention 3. Presence of other underlying disorder
Rate Of Correction-depends on acuity of its occurrence and neurological symptoms.
Risk of Rapid overcorrection➡️CPM➡️Quadriplegia
![Page 21: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/21.jpg)
B. Chronic Asymptomatic hyponatremia:-Risks of iatrogenic injury increases actually.
Osmotic adapted brain cells➡️osmotically destabilize after rapid correction.
Some suggest even modest rate for this i.e. 5-8 mEq/l over 24 hours.
A. Acute Symptomatic Hyponatremia:-- If Severe Use Hypertonic Saline or Saline Hypertonic to Urine of that patient.
Rate of correction should never be >10 to 12 meq/l over the 24 hr. In Severe Hyponatremia-immediate rise needed should not be > 1-2
meq/l/hr for first 3 to 4 hours
![Page 22: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/22.jpg)
✔ Change in [Na+] after giving 1 litre of fluid is determined by
🔼[Na+]={[iNa+]+[iK+]-[sNa+]}/{TBW +1}
(TBW=0.6 LBW in Men and 0.5 LBW in women) ✖ ✖
✔ Desired Rate of Correction in meq/l/hr devided by Delta [Na ] gives us rate of administration of that particular fluid in l/hr.
![Page 23: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/23.jpg)
Example-80kg woman is seizing.Her Na is 108 meq/l.calculate rate of type of fluid u will use in this case.??
ANS= IV Solution Osmolality Sodium Glucose
D5W 278 0 50
0.45% NaCl 154 77 0
0.9% NaCl 304 154 0
3% NaCl 1024 514 0
RL 274 130 0
RL has 109 meq/l chloride,4 meq/l of K+,1.5 meq/l of Ca2+ and 28 meq/l Lactate.
![Page 24: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/24.jpg)
Ans 200ml/ hr for 3 to 4 hrs and not more than 1 lt total in a day.
Rate of correction = 1 to 2 meq/l/hr for first 3 to 4 hours
Means of correction = hypertonic saline having Nai 513 meq/l➡️
One litre of 3% saline will raise Na+ by 🔼Na= (513-108)/(80 0.5+1)=10 meq/l✖
Rate = (2 meq/l/hr)/(10 meq/l per litre of 3%NS) = 200ml/hr for first 3 to 4 hrs
To prevent change of >10 to 12 meq/l over 24 hr, no more than 1ltr should be given.
![Page 25: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/25.jpg)
For Hypovolemic asymptomatic hyponatremia:-Isotonic saline.
For Hypervolemic asymptomatic hyponatremia:-in CHF and Cirrhosis.Although effective volume is decreased.
Water restriction and increasing water diuresis helps.
Oral intake<Daily urine output.
Use of loop diuretics -Reduce Cortico-medullary osmotic gradient by decreasing medullary osmolarity hence render ADH ineffective.[So Free water excretion>Na loss]
Role of Vasopressin # may also be useful in addition to SIADH(Euvolemic)
![Page 26: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/26.jpg)
For Euvolemic Asymptomatic Hyponatremia (SIADH):- First line therapy = Water Restriction and correction of any
contributing factors(Nausia,Pneumonia,Drugs) Water restriction:-roughly to 500ml less than urinary output.
o If (Urine Na+ + Urine K+)/Serum Na+ < 0.5 ➡️1 ltr /dayo If (Urine Na+ + Urine K+)/Serum Na+ 0.5 to 1 ➡️500ml/day o If (Urine Na+ + Urine K+)/Serum Na+ >1 ➡️ Means negative renal free
water clearance with active reabsorption of water.Any amount of water given may be retained.
Therapy directed to enhance free water excretion—Vaptans,Li and Demeclocycline(DOC 150-300mg PO tds to qid).
![Page 27: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/27.jpg)
For Euvolemic hyponatremia with severe symptoms or signs:-
Hypertonic saline can be infused at roughly <0.05 ml/kg body weight in per minute with hourly sodium levels measured until Sodium increases by 12 mew/l or to 130 meq/l,whichever occurs first.
Coinivaptan, a non peptide V2 receptor antagonist, given either PO (20-120 mg bid) or iv (10-40 mg)
![Page 28: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/28.jpg)
Plasma [Na+] >145 meq/L (a Hyperosmolar Condition) Primary Na+ gain or a Water Deficit due to -
o Impaired Thirst Response - Physical restrictions,or mentally impaired patient
o Due to Water loss :-1. Nonrenal Water Loss—Skin and respiratory tract(insensible),GI loss like diarrhea
mainly osmotic diarrhoea and viral gastroenteritis . 2. Renal water Loss - Either Osmotic Diuresis or DI.• Osmotic Diuresis:-High osmolar feeds,and glycosurea,stress dose of steroid. • DI-CDI or NDI (Li, Demeclocycline, amphotericin, hypercalcemia, Hypokalemia,
medulary wash out and intrinsic renal ailment.
HYPERNATREMIA
![Page 29: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/29.jpg)
o Hypernatremia due to Primary Na + gain :-1. After repeat hypertonic saline 2. Chronic mineralocorticoid Excess.
o Transcellular shift of water from ECF to ICF :-In transient intracellular hyperosmolality as in Seizures or Rhabdomyolysis.
![Page 30: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/30.jpg)
Clinical presentation:- Contraction of brain cells➡️Altered mental
status,weakness,neuromuscular irritability,Focal neurological deficit,even coma and Seizures.
If CDI/NDI - Polyuria and thirst. Signs of volume depletion or neurological signs are
generally absent unless associated with thirst abnormality.
![Page 31: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/31.jpg)
DIAGNOSTIC APPROACH
![Page 32: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/32.jpg)
Issues:- 1. rate of correction 2. the appropriate intervention 3. presence of other underlying disorders
Rate of correction-depends on acuity and neurological symptoms.
Should be reduced by roughly 10 to 12 meq/l/day in Symptomatic hypernatremia.
In Chronic asymptomatic case-more moderate rate 5 to 8 meq/l/day.
TREATMENT
![Page 33: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/33.jpg)
Intervention: By administration of Water preferably by mouth/RT IVF- D5W,or 1/4NS Free Water Deficit ={([Na+]-140)/140}✖TBW It is although helpful in estimating water deficit but don't tell rate.
Ongoing Water Losses
Calculate electrolyte-free water clearance, CeH2O
CeH2O = V (1 − UNa + UK)/Pna
where V is urinary volume, UNa is urinary [Na+], UK is urinary [K+], and PNa is plasma [Na+]
![Page 34: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/34.jpg)
Insensible loss:-10 mL/kg per day: less if ventilated, more if febrile
Total:-Add components to determine water deficit and ongoing water loss; correct the water deficit over 48–72 h and replace daily water loss.
Avoid correction of plasma [Na+] by >10 mM/d
![Page 35: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/35.jpg)
Specific therapy for underlying cause :-
Hypovolemic Hypernatmia – IVF/Oral fluids
Primary Na gain hypernatremia-Stop iatrogenic Na+
DI without Hypernatremia-means thirst mechanism is intact .Rx is for symptomatic polyuria only.
CDI-Vasopressin analog DDAVP
NDI-Low Na+ diet combined with Thiazide diuretic will decrease polyuria through inducing mild volume depletion.IT enhances proximal reabsorption of salt and water,decreasing free water loss.
Low protein diet-futher decrease urine output by minimizing solute load that must be excreted.
![Page 36: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/36.jpg)
Example question:A 70 kg man with diarrhea(2ltr/d) from laxative abuse presents with obtundation. And [Na+]=164meq/l,[K+]=3.A replacement fluid of D5W with 20meq KCL/L is chosen. Give Fluid infusion rate.??
Ans=
IV Solution Osmolality Sodium Glucose
D5W 278 0 50
0.45% NaCl 154 77 0
0.9% NaCl 304 154 0
3% NaCl 1024 514 0
RL 274 130 0
![Page 37: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/37.jpg)
Ans= D5W at 500ml/hr for first 3 hrs and total of 3 lt in a day
Choice of fluid= D5W with 20 meq KCL/litre
🔼Na= (0-164)/(70 0.5+1)=-4 meq/lt✖
Total fluid req per day=12/4=3 litre over a day
Rate in first 3 to 4 hr = (2 meq/lt/hr)/(4meq/lt)=500ml/hr for first 3 hrs at the max
Not more than 3 lt should be given in a day.
![Page 38: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/38.jpg)
Vaptans
![Page 39: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/39.jpg)
![Page 40: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/40.jpg)
![Page 41: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/41.jpg)
![Page 42: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/42.jpg)
![Page 43: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/43.jpg)
![Page 44: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/44.jpg)
![Page 45: Hyponatremia and hypernatremia (3)](https://reader030.fdocuments.net/reader030/viewer/2022013115/55b6d88fbb61eb100f8b47eb/html5/thumbnails/45.jpg)