Critical Care Mgmt of Poisonings
Download
Report
Transcript Critical Care Mgmt of Poisonings
Elliot Melendez, MD
Objectives
Discuss Principles of Toxin Assessment
and Screening
Discuss toxidromes and their management
Discuss specific toxins
I will try not talk about decontamination or
elimination of toxins
I will not follow Fuhrman word-for-word
You should have read the 2 chapters (98,99)
Epidemiology
> 2 million calls to poison control centers per
year
~ 66% involve < 20 years
~ 52% < 6 years
Only 25% require referral to a health care
facility
1 of 8 require critical care admission
Mortality
2.1% < 6 years
8.1% < 20 years
Epidemiology
Highest incidence in 1-3 year olds
(accidental)
Boys > girls
Children with developmental delay or pica
Second peak in adolescents
suicide attempt or experimentation
Females >>> males
Anorexia and psychiatric conditions risk
factors
Epidemiology
Most occur when parents distracted at
home
2nd most common site is at grandparents’
homes
91% occur in the home
Many involve household products or meds
that are left open and being used at the
time
Pediatric Ingestions (< 6 yrs)
Cosmetics
Cleaning
Analgesics
Plants
FB
Cough/cold
Topicals
13.3%
11.0%
7.6%
7.1%
6.3%
5.5%
5.4%
Insecticides
Vitamins
Antimicrobials
GI preps
Arts/crafts
*Hydrocarbons
Antihistamines
3.9%
3.3%
3.1%
3.0%
2.5%
2.2%
1.9%
Epidemiology
Agents involved known in most cases
In unknown cases, recognition of a toxic
syndrome may help in management
Common toxic agents leading to
hospitalization
Caustics
Rx Meds (antidepressants)
Analgesics (acetaminophen)
Heavy metals (lead)
Agents Leading to ICU
Rx meds
TCA
Anticonvulsants
Digitalis
Opiates
Alcohol
Hydrocarbon household products
Pediatric Pitfalls
Suspicious if:
Altered mental status
Multiple organ dysfunction
New onset, afebrile sz
Acute onset of presenting sx
Hx of previous ingestions
Current household stress/pregnancy/visitors
Pediatric Pitfalls
Difficult Hx:
Uncooperative/preverbal patient
Abuse
Fear of parental discipline
Get the bottle!
Assessment of Poisoned Patient
An accurate history is vitally important.
Parents usually minimize the child’s
exposure to a toxin in order to deny
threat of injury or assuage guilt
However, frequently, the precise time
and toxin are accurately known.
Evaluating for the Unknown
Substance
History
Obtain ingredients in suspected toxins
Ask to see containers
Assume the worst possible scenario in
calculating max dose
Use max amt of missing tablets or liquid
Concentration of drug or chemical
Child’s weight
Priorities
Assess for medical stability
A, B, C, D’s
Airway/Breathing – Consider intubation?
Upper airway obstruction
Excessive bronchial secretions
Loss of airway reflexes
Respiratory failure
Priorities
Circulation
Assess and treat hypertension and tachycardia
○ Typically if patient is agitated, use sedatives first
○ Avoid non-selective blockers
Treat hypotension with fluids first, and if needed,
use direct agonists
Disability
Protect patient from self-harm
Treat seizures and protect airway
Diagnosis via Toxidromes
Why don’t they work?
Memorization?
Not all clinical criteria may be present
Polysubstance ingestion complicates clinical
signs and symptoms
What Works?
Exam
And what poison control wants to hear!
Vital signs: Temp, HR, BP, RR, Sats
Pupil size
Skin (dry or wet)
Level of Consciousness/Mental status
Let’s Work this Through
Temperature
Fever
Sympathomimetics/Anticholinergics
ASA
Neuroleptic malignant syndrome, MH
Hypothermia
Depressants
Alcohol
Barbiturates
Let’s Work this Through
Heart Rate
Tachycardia
– Sympathomimetics/Anticholinergics
– Antihistamines
– TCA
–
Bradycardia
Ca channel and beta blocker, pure alpha
agonists
Digoxin
Opiates/Sedative hypnotics
Clonidine
Cholinergics/Organophosphates
Let’s Work this Through
Blood Pressure
Hypertension
– Clonidine?
– Sympathomimetics/Anticholinergics
– Trauma, CNS bleed from adrenergics
Hypotension
Ca channel and beta blocker
Barbiturates
Opiates
Sympatholytics - clonidine
Vasodilators/Diuretics
Let’s Work this Through
RR and O2 sats
Respiratory Depression
Opiates
Barbiturates
Respiratory distress
ASA (metabolic acidosis)
– Sympathomimetics/Anticholinergics
– Organophosphates
Let’s Work this Through
Pupil Size
Pupils Small (Miosis)
Cholinergics
Opiates
Clonidine
Organophosphates
Sedatives/Barbiturates
Pupils Dilated (Mydriasis)
Sympathomimetics/Anticholinergics
Antidepressants (SSRI, TCA)
Let’s Work this Through
Skin
Wet
– Sympathomimetics
– Organophosphates
– Cholinergics
Dry
Anticholinergics
Let’s Work this Through
Mental Status
Agitated/Confused/Seizures
Sympathomimetics/Anticholinergics
Withdrawal syndromes
Depressed
Alcohols
Opiates/Barbiturates
Sedatives/Hypnotics
TCA
Laboratory Studies
Chem 10
Calculate serum anion gap
Pregnancy test
EKG
Sosm
Calculate osmolar gap if alcohol suspect
LFTs, Coags
Blood gas
Urine pH
X-rays
Laboratory Studies
Blood levels useful to assess risk
ASA, Tylenol, anticonvulsants, alcohol
Tox Screens
Only occasionally reveals an unanticipated
toxin
Most commonly confirms what is suspected
from history and exam.
Tox Screens
Know you institutions screens and their
limitations
Suboxone, methadone, and
dextromethorphan do not show up on
urine tox
Benadryl, Tegretol cross-react with TCA
screen
ICU Management
Mostly Supportive
Very few antidotes
Consider “Coma” Cocktail
Naloxone
Glucose
Thiamine
Flumazenil
Physostigmine
Consult with local poison control
Specific Cases
16 y/o girl with history of anorexia is
brought to ED for confusion, agitation
What do you want to know?
Case #1
Temp 100.3
HR 130
BP 150/90
RR 20
O2 sat 99% RA
What else?
Case #1
Pupils dilated, poorly reactive
Skin: Dry
Mental Status
Agitated
Paranoid
Picking things from air
Case #1
Diagnosis?
Case #1
Anticholinergic syndrome
Drugs:
TCA
Antihistamines
Belladona
Others
Labs?
Labs
Chem 7 normal
CBC normal
Urine tox negative
Serum tox negative
Tylenol, ASA, TCA, EtOH
EKG normal
Mother asks, “Could this be from her new
appetite stimulant medication.”
Management
Treat agitation with sedatives as needed
Diagnostic test?
Diagnostic Test?
Physostigmine
Ach-ase inhibitor, transient
Risks:
○ Seizures
○ Asystole
○ Have atropine available!!!!
Case #2
16 y/o girl just broke up with her
boyfriend, presents with seizure.
What do you want to know?
Case #2
Temp 100.3
HR 130
BP 150/90
RR 20
O2 sat 99% RA
Seizing
What else?
Case 2
What do you mean what else?
Treat the seizure!!!
Ativan, Ativan seizure stops
Okay, now what else?
Case #2
Pupils dilated, poorly reactive
Skin: Dry
Mental Status
Depressed, intermittent agitation
Labs?
Labs
Chem 7 normal
CBC normal
Tox screens sent
EKG with QRS 0.12
Mother states no meds in home other
than her migraine meds
Case #2
What do you do next?
Case #2
Management
Depression
? Migraine medication
Seizure
Anticholinergic syndrome
Tachycardia with QRS >0.1
Case #2
TCA = Tachycardia, Convulsions,
Anticholinergic
Treatment?
Case #2
Treatment
Alkalinize the serum!!!
NOT THE URINE
NaHCO3 IVP until QRS < 0.1
How much?
As much as if takes!!!
If this symptomatic, start NaHCO3 drip once
QRS narrowed, goal pH 7.45-7.55.
If nonsymptomatic, NS infusion at 1.5
maintenance, with NaHCO3 at bedside
Case #2
Seizes again
Ativan doesn’t stop seizures after 2
doses.
Next?
Case #2
Still Seizing
DO NOT GIVE PHENYTOIN
Na channel blocker, which is what TCA’s do
and can make things worse
Continue NaHCO3 push and Ativan,
consider pentobarbital, Propofol
TCA Toxicity
TCAs block Na channels leading to effects
Seizures correlated with QRS > 0.1
Arrhythmias with QRS > 0.16
Rarely, prolonged QTc (but not without QRS
widening)
You don’t have TCA toxicity without
tachycardia.
If initially asymptomatic, and no symptoms by
6 hrs of ingestion, PICU monitoring not
needed.
Other Notable Ingestions
Serotonin Syndrome
Altered MS, Increased muscle activity, clonus,
autonomic instability
Seen with SSRI overdoses, combination of
ingestions leading to serotonin increase
ASA
Metabolic acidosis, but respiratory alkalosis
Alkalinize urine!!!
If tinnitus, level > 30.
Think of sources other than ASA
○ Bismuth, oil of wintergreen, topical acne meds
Summary
VS, Pupils, Skin, MS should give you a
clue to agent
Tox screens rarely helpful
Look at AG and Sosm when appropriate