Transcript Acute Water Intoxication

Acute Water Intoxication
December 17, 2003
Bruce R. Wall, MD
Good old fashioned nephrology
(with a large dose of pulmonary)
• Most nephrologists would chose to evaluate
and treat a SODIUM of 110 mEq/L rather
than a BUN of 110mg%
• “Be careful what you ask for… you just
might get it…”
• Lt.Col. Theodore R. Wall, USMC, Retired
• Patient admitted from ER with hyponatremia
and respiratory failure… no problem…
Today’s lecture:
• Chronic polydipsia – not this case
• Case presentation
• Laboratory review
• Brief discussion of water intoxication
• Pulmonary aspects @ Dr Weinmeister
Input minus output equals
accumulation
• 75 kg male
• 60% water = approx 45 Liters TBW
• Intracellular
30 L
280mosm/kg
[K+] 140mEq/l
Extracellular
15 L
280mosm/kg
[Na+] 140mEq/l
How much water was ingested?
• Initial TB solute: 280 X 45 =12,600 mosmol
• Initial ECF solute: 280 X 15 = 4,200 mosmol
• Initial intracellular: 12600 – 4200 = 8,400 mosmol
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TBW : 45kg + 6 kg = 51 kg
TB OSM: 12,600 / 51kg = 251mosm/kg
ECF volume: 4200 / 251 = 16.7kg
intracellular volume: 8400 / 251 = 33.4kg
How much water?
• Assume an ingestion of 6 liters:
serum osmolality of 251mosmol/kg
• Estimated nadir [Na+] = osmolality / 2 =
125.5mEq
• Effective Posm is approximately 2 X [Na+]
Case Presentation
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21 year old AAM student at SMU
CC: can not be obtained (intubation)
History obtained from family members
Patient was asked to drink 3 - 4 gallons of water
(with hot sauce), as part of a fraternity hazing on
Friday evening
Post ingestion, patient was confused, and became
‘less responsive’
At 4AM, patient developed a seizure, yet was not
transported to Presby ER until 7AM
Hospital day:one
• Profound shock/hypotension – poor
response to high dose pressor medications
• Immediate respiratory failure with severe
agitation and hypoxemia; endotracheal
intubation confirmed “drowning”
• Transfer to ICU maximal support: 100%
oxygen, maximum PEEP, IV norepinephrine
• Initial SODIUM = 126mEq/L (IV @KO NS)
Case presentation: continued
• Past medical history: none
• Social history: 2 year football player for
Austin College. No drug or alcohol history
Mother arrived from Houston; Father
arrived from US Virgin Islands (lives in
Wash D.C.)
• Medications: IV pressors, antibiotics
• ROS: not available
Physical exam:
• BP 100/60 on very high dose IV pressors; pulse
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110 sinus tachycardia; R per vent; high pressures
Very muscular patient, intubated PO, who
eventually developed subQ crepitation from
barotrauma
HEENT: mild swelling; anicteric NECK: WNL
LUNGS: bilateral breath sounds; increased rate
COR: no murmur, increased HR
ABD: benign, although later the CT was
abnormal…
Ext: no cyanosis; warm; slowly progressive edema
Neuro: unresponsive pupils; ? signs of herniation
prompted use of IV mannitol
Admit labs
• WBC 17K
76%neutrophils, 6%lymphs
Hgb/Hct 13.2g%/38%
Plts 380K
• Urinalysis: 2+ blood, few RBC’s, 360mOs/kg
• Initial Serum Osm: 272, falling to 263 in
8hrs
• Toxicology screen negative for tylenol, PCP,
ethylene glycol, MDMA, salicylate, ethanol,
cocaine, barbiturates, and narcotics
• CXR: ? RUL pneumonia
• CT Head: cerebral edema, especially in
retrospect
Additional admit labs:
• Calcium 8.6mg/dl
Phos 4.2g/dl
• Total protein 7.6g/dl
Albumin 4.8g/dl
• Alk phos 63
LFT’s mildly elevated
• INITIAL CPK 2100
• INITIAL BUN 10mg%
CREAT 1.0mg%
• ANION GAP 21
• Therefore, working diagnosis of (+) AG
lactic acidosis from seizure, 3 hours PTA
Electrolytes day one, as serum
osmolality fell from 272 to 263…
Na+
K+
ClCO2
AG
Creat
U osm
PO4
CPK
0800
126
4.6
89
16
21
1.0
360
4.0
2100
1130
117
3.8
88
19
10
1.1
1320
120
3.6
1800
116
4.0
90
22
9
1.1
5
1.2
473
4.4
3400
2300
117
3.8
4000
Electrolytes: day 2
0300
1045
1300
1600
2000
Na+
116
128
130
132
134
K+
4.6
4.4
CO2
26
25
AG
6
8
Creat
1.1
1.3
PO4
1.7
2.5
CPK
6200
U osm
803
therapy
1.2
10,500
122
600
DDAVP
Hospital course
• Hemodynamics and oxygenation were tenuous on
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day one…
Patient was considered for extra-coporeal
oxygenation therapy, resulting in a transfer from 3
ICU to 4 ICU
Post transfer, his BP and PO2 IMPROVED
Abnormal CXR: bilateral infiltrates, air under R
hemidiaphragm
CT scan: larger amt of air surrounds tail of
pancreas, (L) kidney, anterior aspect of psoas
muscle, tracking down from mediastinum
Hospital course: continued
• Electrolytes were normal, by hospital day 3
• EEG always showed electrical activity
(patient had been severely hypoxemic, but
never required ACLS)
• CNS began to improve by hospital day 4
• Ventilator support was weaned by day 7
• Transfer to floor day 8
• Discharged home day 10
CNS damage associated with acute
hyponatremia
• CPM: rare neurologic disorder reported in
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malnourished/alcoholic patients
MORE COMMON – brain edema, with uncal and
tonsillar herniation with diffuse cerebral
demyelination secondary to increased intracranial
pressure, with necrosis, and hypoxic brain damage
Compression of medullary respiratory center
because of brain swelling, above 5 to 8% of
baseline volume can lead to herniation -- fixed
pupils, hypoventilation, cardio instability, impaired
temperature control, pituitary and hypothalamic
infarction also possible
Water intoxication in cattle
• J AFR VET ASSOC 1999 DEC; 70(4)
• Water intoxication is common in cattle, and
also has been described in other domestic
animals. Comprehensive description is
lacking…
Fatal water intoxication: Journal of
Clinical Pathology Oct 2003 p 803
DJ Farrell et al
• 64 yo woman with known MV disease
• Compulsively drinking water, one evening, in range
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of 30 to 40 glasses
Hours later was described as “hysterical”
Fell asleep, and found dead next morning
Postmortem: no tumor, bilateral pleural effusions,
LVH with large heart; increased cortisols
Na+ = 92meq/L (vitreous fluid, usually stable)
Acute delirium, seizures, coma, and death
Autopsy case of rare iatrogenic water
ingestion; Chen et al, Tongji Med Univ,
Forensic Sci International: Nov 95
• 21 yo female suicide attempt (powder
scraped from 18 matches)
• 1700 hrs: 3L of water
1730 hrs: 800ml
• 1800 hrs: 4L of water, via NG tube
• Headache, dyspnea, cyanosis, then coma
• Autopsy: cerebellar herniation, Na+ 112,
pulmonary edema, trachea and bronchial
tubes full of fluid…
Literature review: Forensic Science
International (1995): continued
• 534 papers over 17 years – only 16
fatalities
• 15 cases diagnosed during hospitalization
for various types of psychosis
• Water intoxication is unusual in normal
people, and death is even rarer
• Case report of death within 2.5 hrs is rare
Fatal child abuse by forced water
intoxication
• Pediatrics 1999 JUN;103
Alan Arief,MD
• 3 children punished by forced intoxication
• > 6 liters
• Seizures, emesis, coma, hypoxemia,
average sodium 112mEq/L
• Autopsy confirmed cerebral edema
• Tried and convicted
Death by hyponatremia as result of
water intoxication in a
Army trainee
• MIL MED 1999 MAR;164
• Excessive water intake by athletes during
endurance races, to prevent heat injury has
been the recommendation
• Describe a case of programmed drinking >
8 liters during initial training
• One death, cerebral edema with seizure
Death by Water intoxication
MIL MED 2002 May; 167
• 3 deaths in recruits, usual water load of 6
to 10 liters in 2 to 3 hrs
• “safe limit” probably 1 liter per hour
Chronic Polydipsia and
hyponatremia
• Psychiatric patients, especially schizophrenia, often
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have problems with water balance
6% to 8% have a history compatible with
compulsive water drinking; ½ of these pts had
intermittent symptoms of hyponatremia
Normal patients can excrete 10 to 15 liters/d by
decreasing Uosm from 40 to 100 mosm/kg
Episodes of transient ADH release with acute
psychotic episodes
Carbamazepine and fluoxetine are associated with
SIADH
Chronic polydipsia
• This is an uncommon clinical scenario, but does
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not apply to our current case (which is rare)
“Rx” hypontremia with acute encephalopathy
rate of correction – 0.5 to 1 meq/l per hr
(until a sodium of 120meq/l)
Never actively correct > 130meq/l