Transcript poisoning 2004

POISONING 2004
Kent R. Olson, MD, FACEP
Medical Director, SF Division
California Poison Control System
Case 1: Metabolic Acidosis
20 year old woman found in her
parked car, comatose (GCS 8)
3 empty bottles of Tylenol
BP 100/50 HR 140-160 RR 38
Na 150
pH 6.98
K 3.5
Cl 124
pCO2 12
HCO3 6
pO2 198
“MUDPILES”
Methanol
Uremia
DKA
Phenformin, Paraldehyde
INH
Lactate
Ethylene glycol, Ethanol
Salicylate
Lactic Acidosis
Many possible causes:
Hypoxia-ischemia
Cyanide poisoning
Carbon monoxide poisoning
Metformin
INH . . . and many others
Order a serum lactate level
“SALAD”
Gives you a quick “what to order”:
Salicylate (order a stat [ASA])
Alcohols (toxic alcohols – order Osm)
Lactate (order a state [Lactate])
Anuria (BUN, Cr)
DKA (check glucose)
If the [Lactate] = normal
Then, you have fewer things to
consider, e.g.:
Toxic alcohols
Methanol = formic acidosis
Ethylene glycol = glycolic acidosis
Ketoacidosis
Mostly beta-hydroxybutyrate
Case, continued . . .
Salicylate negative
BUN/Cr = 5/1.1
Glucose 400 mg/dL
Lactate 18 mmol/L
COHgb not detected
Osmolality not sent
“MUDPILES”
Methanol
Uremia
DKA
Phenformin, Paraldehyde
INH
Lactate
Ethylene glycol, Ethanol
Salicylate
What was it?
Serum acetaminophen = 917 mg/L !!
She was treated with NAC, IV
NaHCO3 (repeat pH 7.29), insulin
Next day AST, ALT began to rise
Peak measured ALT 5318
Bili to 2.8, INR 3.1
Acetaminophen overdose
Acidosis, coma uncommon without
fulminant liver failure as prior cause
Occasional cases of early coma,
severe acidosis with very high drug
levels - despite absent liver failure
Mnemonics . . just remember:
“Today’s clinical pearl
may end up as
tomorrow’s fecalith.”
. . .John Wallace, MD c.1979
Serum acetaminophen (APAP) levels after
ingestion of “Tylenol Extended Relief”
1000
Serum APAP level
100
APAP
(mg/L)
10
Probably Toxic
Possibly Toxic
1
0
5
10
15
20
Note: co-ingestion of Nyquil plus up to 44 g Tylenol ER
Ref: Bizovi K et al: J Toxicol Clin Toxicol 1995; 33:510
25
hrs
New drug: Acetadote™
IV formulation of N-acetylcysteine
FDA approved January 2004
Not yet on the market
Dose? The UK-European protocol:
150 mg/kg in 200 mL D5W over 15 min +
50 mg/kg in 500 mL D5W over 4 hours +
100 mg/kg in 1 L, over 16 hrs
Duration of NAC treatment?
Current US oral NAC protocol = 72 hr
Acetadote IV = 20 hr
Onset of rising AST, ALT ~ 24-30 hr
We recommend Rx (or at least
observation) until ~36 hrs after the
ingestion to r/o liver damage
Case 2: Little Blue Lady
80 year old woman just returned from
transeophageal echocardiogram
Perioral cyanosis and blue nail beds
Otherwise asymptomatic
Pulse oximetry 87% - did not improve
with high-flow oxygen
Arterial blood gases:
pH = 7.43
pCO2 = 36
pO2 = 266
Methemoglobinemia
Fe2+ in heme is oxidized to Fe3+
Unable to carry oxygen
Many causes: (oxidants)
Benzocaine spray (in Hurricaine™)
Dapsone
Phenazopyridine
Nitrites (eg, amyl nitrite)
Another crappy hemoglobin
67 year old man found unresponsive
and covered with vomitus
Barbeque was heating the trailer
COHgb 33%
Intubated, hypotensive on Levophed
Candidate for HBO?
Carbon monoxide poisoning
CO poisoning, continued . . .
Can cause coma, seizures, death
Survivors may have varying degrees of
neurological sequelae
Persistent coma, vegetative state, etc
Subtle mood and memory disorders
Incidence up to 30-40%
Controversy over treatment
Hyperbaric oxygen (2.5 ATM)
versus
Normobaric oxygen ?
Literature is inconclusive
Most reports are uncontrolled case
series
Only two RCTs
Australian study: no difference
Weaver study: small benefit with HBO
Weaver recommends HBO if:
COHgb > 25%
History of loss of consciousness
Metabolic acidosis
Age > 50 years
Cerebellar findings on neuro exam
Another CO case:
55 year old man found unconscious on
his yacht
He had gone downstairs 10 min earlier
to check on a burning odor
Pulled out to fresh air, awake in 10
minutes
In ER 2.5 hrs later, COHgb 14.4%
alert and normal neuro exam
Child with a Seizure
14 month old boy had a seizure at
home. No prior Hx of seizures.
Had been playing with Effexor bottle
Second seizure on arrival in ER
BP 138/87
Pupils dilated
HR 150
RR 28
T nl
Common causes of seizures
Tricyclic antidepressants
Newer antidepressants (SSRIs)
especially bupropion (Wellbutrin™)
Amphetamines/cocaine
INH
Diphenhydramine
Tramadol (Ultram™)
Toxicology screen showed:
Positive for methamphetamine
Not tested for venlafaxine (Effexor™)
Potential false (+) for amphetamines:
Ephedrine, MDMA, pseudoephedrine, etc
Bupropion, Labetalol, Ranitidine,
Sertraline, Selegiline, Trazodone,
others . . .
Final case:
22 year old man ingested 60 lithium
tablets (300 mg)
Asymptomatic 1 hour later in ER
How to decontaminate the stomach?
Gut decontamination
Goal: limit systemic absorption
Possible methods:
Induced emesis
Gastric lavage
Activated charcoal
Cathartics/whole bowel irrigation
Induced emesis
Don’t use:
Salt water
Finger gag
Ipecac?
Soapy water?
Ipecac syrup
Easy to perform, but
NOT very effective
Risks:
Pulmonary aspiration
Wretching, GI injury
Delay in administering charcoal
Bottom line: OUTDATED
“Pumping the
stomach”
NOT very effective
Risks:
Aspiration
GI trauma
Delay to administering AC
Bottom line: RARELY used
Activated charcoal
Finely divided powder
Huge surface area
Drugs and poisons are
adsorbed to surface
Does NOT bind:
Iron
Lithium
Activated charcoal . . .
More effective than ipecac, lavage
First choice for most drugs & poisons
Whole Bowel Irrigation
Mechanical flush
GoLytely or COLYTE
Balanced salt solution
Nonabsorbable PEG
No net fluid loss or gain
Good for:
Lithium, iron, foreign bodies
1-800-222-1222
New national toll-free hotline #
Dial from anywhere in the USA
Connects to regional poison center
24-hr consultation
PharmDs with physician back-up