CASE STUDY IN HYPONATREMIA - Welcome to CCEHS · CASE STUDY IN HYPONATREMIA 25th Annual Clinical...
Transcript of CASE STUDY IN HYPONATREMIA - Welcome to CCEHS · CASE STUDY IN HYPONATREMIA 25th Annual Clinical...
CASE STUDY IN HYPONATREMIA
25th Annual Clinical Update in Geriatric Medicine Conference
DAVID J. LEVENSON MD
APRIL 6, 2017
CASE PRESENTATION
• YOUR MEDICAL ASSISTANT SENDS YOU THE FOLLOWING MESSAGE:
• “YOUR PATIENT JOAN SMITH, AGE 76, HAD LAB WORK DONE LAST WEEK.
• THE SERUM SODIUM IS 120 meq/L.”
WHAT COMES TO MIND?
• SIADH
• Cancer
• Psych meds
• Normal saline
• Tolvaptan
• CHF
• Head CT
• Osmotic demyelination
• Urea
• Urine osmolality
• 3% saline
• Hypothyroid
• Urine lytes
• Hyperosmolar
hyponatremia
• Central pontine myelinolysis
• Salt tablet
• Free water excretion
• Cirrhosis
• Thiazides
UNSPOKEN PHRASES
“WHY DOES IT HAVE TO BE SO COMPLICATED?”
“NORMAL SALINE”
“LET THE NEPHROLOGISTS DEAL WITH IT.”
A SIMPLE APPROACH
1. What does the patient have?
2. Why does she have it? What is the DDX?
3. How bad is it?
4. What shall we do -
– Diagnostically?
– Therapeutically?
1. WHAT DOES SHE HAVE?
• HYPONATREMIA
• HYPOOSMOLAR (MEASURE IF NEEDED)
• THE RATIO OF SALT TO WATER IS LOW – EXCESS WATER BUT NORMAL SALT CONTENT
or
– GREATER EXCESS OF WATER THAN SALT
or
– GREATER DEFICIT OF SALT THAN WATER
• IMPAIRED WATER EXCRETION
2. WHY DOES SHE HAVE IMPAIRED WATER EXCRETION?
• CAUSES FOR IMPAIRED WATER EXCRETION – ADH (VASOPRESSIN)
– (LOW GFR)
IF KIDNEY FUNCTION IS NORMAL,
SHE MUST HAVE ADH EXCESS
IS A VOLUME DISORDER STIMULATING ADH RELEASE?
• IF YES, THE PRESENCE OF ADH IS APPROPRIATE FOR
THE SITUATION – FIXING THE VOLUME DISORDER MAY SOLVE THE
HYPONATREMIA PROBLEM
– DETERMINE IF VOLUME STATUS IS LOW OR HIGH, AND WHAT ELSE IS WRONG WITH THE SYSTEMIC HEMODYNAMICS;
• IF NO, THEN THE PRESENCE OF ADH IS NOT APPROPRIATE – i.e., VOLUME NORMAL, OSM NOT HIGH
– THIS IS SIADH
– (OR A FEW OTHER THINGS: • hypothyroid, cortisol deficiency, reset osmostat, malnutrition)
WHAT CAUSES SIADH?
• ABNORMAL STIMULI OF ADH RELEASE – PAIN, NAUSEA, ANXIETY, – MEDS – CNS DISEASE – LUNG DISEASE
• ECTOPIC ADH PRODUCTION – CANCER - Lung, small intestine, pancreas, brain, etc.
• INCREASED RENAL SENSITIVITY TO ADH – NSAID, OTHER MEDS
• OTHER – HIV – Etc.
3. HOW BAD IS IT? THREE CRITERIA
• ABSOLUTE SODIUM LEVEL
– COMMON THRESHOLD: Na <120 MEQ/L
• NEUROLOGIC STATUS
– ABNORMAL MENTAL STATUS
– NEUROLOGIC DEFICITS
– SEIZURES, COMA
– CEREBRAL EDEMA
• ACUTE (24 HR) vs. CHRONIC
3. HOW BAD IS IT? THREE CRITERIA
• ABSOLUTE SODIUM LEVEL
– COMMON THRESHOLD: Na <120 MEQ/L
• NEUROLOGIC STATUS
– ABNORMAL MENTAL STATUS
– NEUROLOGIC DEFICITS
– SEIZURES, COMA
– CEREBRAL EDEMA
• ACUTE (24 HR) vs. CHRONIC
4. WHAT SHOULD WE DO - DIAGNOSTICALLY?
• ESTABLISH THE HISTORY
– MEDS, FLUID INTAKE, TIME COURSE
• IS VASOPRESSIN PRESENT?
• IS THERE A VOLUME DISORDER?
• WHAT IS THE NEUROLOGIC STATUS?
• IS THERE OTHER STUFF GOING ON?
– ACUTE ILLNESS, CANCER, ALCOHOLISM, MALNUTRITION, THYROID, ADRENAL DISEASE
4. WHAT SHOULD WE DO - DIAGNOSTICALLY?
• ESTABLISH THE HISTORY
– MEDS, TIME COURSE, FLUID INTAKE,
• IS VASOPRESSIN PRESENT? Uosm >100-150
• IS THERE A VOLUME DISORDER?
• WHAT IS THE NEUROLOGIC STATUS?
• IS THERE OTHER STUFF GOING ON?
– ACUTE ILLNESS, CANCER, ALCOHOLISM, MALNUTRITION, THYROID, ADRENAL DISEASE
4. WHAT SHOULD WE DO - DIAGNOSTICALLY?
• ESTABLISH THE HISTORY
– MEDS, TIME COURSE, FLUID INTAKE,
• IS VASOPRESSIN PRESENT? Uosm >100-150
• IS THERE A VOLUME DISORDER?
• WHAT IS THE NEUROLOGIC STATUS?
• IS THERE OTHER STUFF GOING ON?
– ACUTE ILLNESS, CANCER, ALCOHOLISM, MALNUTRITION, THYROID, ADRENAL DISEASE
IS THERE A VOLUME DISORDER?
• HISTORY:
– MEDS, WATER INTAKE, WEIGHT CHANGE,
• EXAMINATION
– ORTHOSTATIC SIGNS, SKIN TURGOR, AXILLARY SWEAT,
• LABS
– BUN/Cr ratio, UNa <20, FENa <1%,
– BNP, ALBUMIN, URIC ACID
4. WHAT SHOULD WE DO DIAGNOSTICALLY?
• ESTABLISH THE HISTORY
– MEDS, TIME COURSE, FLUID INTAKE,
• IS VASOPRESSIN PRESENT? Uosm >100-150
• IS THERE A VOLUME DISORDER?
• WHAT IS THE NEUROLOGIC STATUS? MSE!
• IS THERE OTHER STUFF GOING ON?
– ACUTE ILLNESS, CANCER, ALCOHOLISM, MALNUTRITION, THYROID, ADRENAL DISEASE
4. WHAT SHOULD WE DO DIAGNOSTICALLY?
• ESTABLISH THE HISTORY
– MEDS, TIME COURSE, FLUID INTAKE,
• IS VASOPRESSIN PRESENT? Uosm >100-150
• IS THERE A VOLUME DISORDER?
• WHAT IS THE NEUROLOGIC STATUS? MSE!
• IS THERE OTHER STUFF GOING ON?
– ACUTE ILLNESS, CANCER, ALCOHOLISM, MALNUTRITION, THYROID, ADRENAL DISEASE
MINIMUM ORDER SET
• ORTHOSTATIC SIGNS
• DAILY WEIGHT
• INTAKE AND OUTPUT
• URINE: LYTES, Cr, OSM, U/A
– BEFORE DIURETICS OR IV FLUIDS
• REPEAT BMP, THEN Q3-6H
• GLUCOSE
• REGULATE THE VOLUME OF FLUID INTAKE
4. WHAT SHOULD WE DO - THERAPEUTICALLY?
• GOALS: – RAISE SODIUM ENOUGH TO ELIMINATE THE RISK
OF NEUROLOGIC DYSFUNCTION AND BRAIN INJURY.
– AVOID RISK OF EXCESSIVELY RAPID CORRECTIOIN
• ISSUES: – HOW MUCH TO INCREASE THE SODIUM LEVEL?
– HOW FAST?
WHAT ARE THE RISKS AND DANGERS OF TREATMENT?
• UNDERTREATMENT – WORSENING HYPONATREMIA
• NEUROLOGIC DETERIORATION
• SEIZURE, COMA
• CEREBRAL EDEMA
• OVERTREATMENT – RAPIDLY RISING [Na+] > 8 MEQ/24H
• OSMOTIC DEMYELINATION SYNDROME
• “CENTRAL PONTINE MYELINOLYSIS”
• APPEARANCE MAY BE DELAYED BY DAYS
EMERGENCY SITUATIONS:
Na <120 and: • SEIZURES, COMA, HERNIATION, STROKE • ACUTE HYPONATREMIA (<24 HOURS) WITH SXS
– MARTHON RUNNERS – POST-OP – WATER INTOXICATION – ECSTASY (AMPHETAMINE) – CNS STRUCTURAL ANORMALITIES
GOAL of RX: RAISE Na by 4-6 meq QUICKLY – GIVE 100 CC OF 3% SALINE OVER 15 MINUTES, REPEAT prn. OTHERWISE: SLOW ONSET OF HYPONATREMIA-> SLOW CORRECTION
STANDARD OF PRACTICE
• DO NOT RAISE NA >8 MEQ IN ANY 24 HOUR PERIOD – ACTIVELY OR PASSIVELY!
• IF YOU DO , YOU MUST REVERSE COURSE AND CORRECT THE OVERSHOOT.
CAUTION
• SOME HYPONATREMIC PATIENTS WILL “AUTOCORRECT” SPONTANEOUSLY AND RAPIDLY, IF THE STIMULUS TO ADH ABATES:
– ACUTE PSYCHOSIS
– SEVERE VOLUME DEPLETION
– TRANSIENT SIADH
– THIAZIDE INDUCED
• THESE PATIENTS MAY REQUIRE VASOPRESSIN +/- D5W TO PREVENT OR REVERSE OVERCORRECTION.
• [Na] MUST BE MONITORED VERY CLOSELY
4. WHAT SHOULD WE DO - THERAPEUTICALLY?
• VOLUME DISORDERS – SALT DEFICIT: NS, 5% ALBUMIN, PRBCS
– SALT EXCESS: FLUID RESTRICTION, IV DIURETICS, INOTROPES, CARDIAC INTERVENTIONS, ?VAPTANS ETC.
• EUVOLEMIC = normal salt, excess water – STOP RELEVANT MEDS, e.g THIAZIDES
– FLUID RESTRICT
– ENHANCE WATER EXCRETION
– ALCOHOLISM, MALNUTRITION:
• INCREASE PROTEIN INTAKE
– ADDRESS DEFICIENCY OF T4, CORTISOL
WHAT’S WRONG WITH SALINE TO TREAT SIADH?
THEORY:
SALINE IS HYPEROSMOLAR VS PATIENT’S BLOOD
BUT:
• PATIENTS ARE EUVOLEMIC; THE SALT LOAD IS EXCRETED
• ADH LEVEL IS HIGH, SO THE WATER IS RETAINED
THE PATIENT WILL BECOME MORE HYPONATREMIC
NOT A SAFE OPTION!
4. WHAT SHOULD WE DO - THERAPEUTICALLY?
• VOLUME DISORDERS – DRY: NS, 5% ALBUMIN, PRBCS – VOLUME EXCESS: FLUID RESTRICTION, IV DIURETICS,
INOTROPES, CARDIAC INTERVENTIONS, ?VAPTANS ETC.
• EUVOLEMIC = normal salt, excess water – STOP RELEVANT MEDS, e.g THIAZIDES – FLUID RESTRICT – ENHANCE WATER EXCRETION – ALCOHOLISM, MALNUTRITION:
• INCREASE PROTEIN INTAKE – ADDRESS DEFICIENCY OF T4, CORTISOL – NO SALINE
THERAPY OF CHRONIC SIADH
GOAL: Na >120 and/or SX RESOLUTION
• ORAL FLUID RESTRICTION: 800-1500 CC/24H
• 3% SALINE 20-40CC/HR (IN ICU)
• SALT PILLS (NaCl 1 GM): 4-12/24H
• LASIX + SALT PILLS
• DEMECLOCYCLINE
• VAPTANS – IV: CONIVAPTAN – MUST INCREASE FLUID INTAKE AT
SAME TIME
– ORAL : TOLVAPTAN – LIMIT 30 DAYS
• ORAL UREA
TREATMENT: SUMMARY
1. TREAT BASED UPON THREE CRITERIA:
– ACUTE OR CHRONIC?
– SEVERE OR NOT?
– VOLUME DISORDER OR EUVOLEMIC?
2. EMERGENT SITUATIONS REQUIRE EMERGENT RX WITH CLOSE CONTINUOUS ICU MONITORING.
3. OVERCORRECTION (> 8 MEQ RISE/24 HRS) CARRIES THE RISK OF PERMANENT NEUROLOGIC INJURY AND DEATH, AND MUST BE REVERSED.
4. MOST CHRONIC HYPONATREMIA WITH Na >120 IS WELL TOLERATED, SO CORRECT SLOWLY.