Case 1- M.H. (Chico State U., California)

18M presents after 3 grand-mal seizures after collapsing during fraternity hazing ritual

Pledges were forced to do push-ups/exercises for hours in raw sewage that had leaked into basement of fraternity

Kept drinking from 5 gallon jug of water which was continuously refilled

Vomitted and urinated on themselves

Case 1

Initial vitals: 120/60 70 20 98% RA T=37.5 Clinically euvolemic Confused

Case 1

Initial labs Na = 110, urine Na <10, serum osmol = 270 How would you treat?

Hyponatremia

Sultana Qureshi, R2Lab RoundsFeb 8, 2007

Matthew Harrington

HypoNa Basics

HypoNa is a symptom of disease Na <135 mEq/L Most common lyte abn in hospital

pts Incidence 1%, increases with age Acute, symptomatic cases,

mortality up to 18%

Quick Physiology Review 3 fluid compartments

(2/3) ICF & (1/3)ECF (InterstitialF + IVF) Na concentration governs movement of

water across these spaces

Body tightly maintains serum osmolality within 1-2% of 275-295 mosmol/kg

Na balance = Renin-angiotensin Water balance = ADH

Quick Physiology Review

Hypotension or low ECF renin release from JGAangiotensin II aldosterone production Na reabsorption and K excretion

Incr serum osmolality, Decr. BP or volume ADH release from post. Pituitary More sens to hypovolemia than low

osmol.

Clinical Features

Absolute Na level not as important as RATE OF DECLINE

SymptomsSerum Na+ (mEq/L) Symptoms

135 - 130 Decreased taste

130 - 125 ThirstAnorexia, N + VMuscle cramps

125 - 120 WeaknessLethargy

RestlessnessConfusion

< 120 DeliriumComa

SeizuresThanks to Moritz!

Approach

Classify Osmolality and Volume status Osmolality

Hyperosmolar – excess solutes (ie glucose) draw water into ECF diluting Na

Iso-osmolar – psuedohyponatremia Hypo-osmolar (MOST COMMON) – excess

water in relation to Na stores (may be incr, decr or n) – categorized by volume status

Hypo-osmolar HypoNa Hypervolemic

CHF, ARF, CRF, cirrhosis/ascites, pregnancy Euvolemic

SIADH, adrenal insuff, hypothyroid, psychogenic polydipsia, sports

Hypovolemic Diuretics, diarrhea, sweating, third-spacing,

salt-wasting nephropathy

Causes of SIADH CNS disease

Brain tumor infarction injury abscess Meningitis/  Encephaliti

s

 Pulmonary disease Pneumonia Tuberculosis Lung abscess Pulmonary

aspergillosis

 Drugs  

Exogenous vasopressin (enuresis)

  Diuretics   Chlorpropamide   Vincristine   Thioridazine   Cyclophosphamide

Most common is hypo-osmolar hyponatremia

Case 2

75F – weak and dizzy x 1 week, falls at home presenting with hip #

PMHx – Hyperlipidemia, HTN, chronic diarrhea NYD

Meds: HCTZ, lipitor Vitals: 85, 110/70, 14, 95% RA

Case 2

Labs: Na- 112, K-4.5, Cl- 82, CO2 -12

Serum osmol – 240 Urine osmol – 300 Urine Na - <10 Cause of HypoNa? How would you treat?

Management

Guided by severity of symptoms and acuity

Chronic Gradual correction <0.5 mEq/L/hr

Acute/Symptomatic Tolerate faster correction up to 1-2

mEq/l/hr

Management CNS symptoms/seizures

Correct with hypertonic saline (3%) until resolved

usually need to increase Na by 4-6 mEq/L only Then correct 8-10mEq/L/day Formula

(Desired [Na+] – measured [Na+] ) x 0.6Wt(kg) = mEq Na+ req’d

Eg (117-112) X 0.6(70) = 210 mEq

Case 2 (continued) It’s July 1st and the Ortho R1 decides to

fluid resuscitate her with NS 2L bolus, then runs it at 200cc/hr

Pt admitted to Ortho Next morning, Na corrected to 136 Later that evening, pt develops

confusion, dysarthria, unable to move her arms and legs

What’s happening? Call stroke team?

Central Pontine Myelinolysis (CPM) Overaggressive correction of the serum sodium level

(usually >12 mEq/L/day)

Destruction of myelin in the pons (due to rapid changes in cell volume?)

Pts may develop confusion, cranial nerve palsies, spastic quadriplegia, or coma

More likely to occur in patients with chronic hyponatremia

Most cases reported in alcoholic, malnourished, and elderly patients

Can develop 1-3 days after rapid Na correction

Diagnosed by MRI

Supportive Management

Treatment (mild-mod symptoms) Hypovolemic hyponatremia

Correct with NS (0.9%) Euvolemic hyponatremia:

Restrict free water intake Treat underlying cause No NS in SIADH:

Worsens due to excessive water retention Lithium and demeclocycline

Hypervolemic hyponatremia: Restrict free water intake +/- diuretics (may increase Na loss)

Case 3 (Jan 12, 2007 – Sacremento, CA)

28F enters radio station competition “Hold your Wee for a Wii” Contestant who could drink the most water

without urinating won Possibly drank up to 2 gallons Nurse called into radio station during

competition stating danger Last heard from while driving home with

severe headache Found dead next morning

Questions?