Windy City EM Joint Conference of all the Chicago Area EM Programs Held at the UIC Forum
Pick Your PoisonToxicology Topics
AKS Overview of Tox
The “Mickey Finn” started in Chicago. A bartender named Mickey Finn would slip a purgative in a patron’s drink causing vomiting/diarrhea. His buddies would then hustle the “sick” patron out into the alley and beat them up and rob them.
The first Poison Control Centerin the nation was in Chicago.
CheemaUrine Drug screens
A positive urine drug screen for amphetamines has about a 1 in 4 false positive rate. There are many meds that can cross react with the urine screen for amphetamines.
Surprisingly, Xanax, Ativan, andKlonopin won’t give a positive urine drug screen for benzos. That is because the screen looks for the metabolite oxazepam and these three benzos don’t get metabolized to oxazepam. It’s unfortunate that the drug screen won’t pick up these common benzos.
Second-hand marijuana smoke is very unlikely to trip a urine drug screen. A patient will not get a positive drug screen for marijuana by being at a concert near others smoking marijuana.
Fentanyl and methadone are not picked up on a urine drug screen. Hydrocodone and hydromorphone are picked up <60% of the time.
Research has shown that taking a history from the patient is superior to the drug screen for identifying illicit drug use. Drug screens rarely change how we manage patients.
Carlson Marajuana and THC Concentrates
50% of people will use marajuana at some point in their lifetime.
Alaska, Oregon, Washington, Colorado and Washington DC allow legal recreational use of marijuana.
In Colorado, there has been a large increase in the number of pediatric patients accidentally exposed to edible forms of marijuana (candy, brownies)
Concentrated marijuana (hash) can cause psychosis. Stopping use of marijuana products for 1-2 weeks can resolve psychosis.
Synthetic cannabinoids can also cause psychosis. There have also been reports of MI’s and strokes in young patients using synthetic cannabinoids. The cause is uncertain but it gets to the point that synthetic cannabinoids are metabolically complex molecules.
THC increases appetite. This is one of the medical benefits of marijuana.
Marajuana can result in amotivational syndrome and attention deficit symptoms.
In a young patient with new onset psychosis you really have to consider concentrated marijuana use as a cause.
Marajuana is stored in adipose tissue. Habitiual users can have a positive screen for up to 12 weeks. Synthetic cannabinoids do not trip a urine drug screen for marijuana. Single use of marijuana will cause a positive drug screen for 2-3 days.
Lank Psychiatric Medications
Bupropion, Citalopram, and Venlafaxine are the 3 SSRI’s that can cause seizures with overdose. Admit these overdoses for 23 hour OBS with telemetry. Citalopram can cause torsades. 2 patients with bupropion overdose have been reported to require ECMO to survive. So these drugs are not totally benign in overdose.
Patients on lithium can have a significant drug interaction with a prolonged course of NSAID’s. A patient on lithium can have a single or few doses of ibuprofen but not 600mg Q8 for 7 days. They can get lithium toxic.
Treat lithium toxicity with fluid and electrolyte management and if the patient appears ill, dialyze them. Dialysis may decrease the incidence of neuro-cognitive sequelae of lithium toxicity.
Bryant Hyperbaric O2for CO
Consider CO poisoning in patients presenting with headache, vomiting, vision changes, altered level of consciousness, and chest pain. CO poisoning is a chameleon and can masquerade as many other diagnoses.
VBG is adequate to measure the CO level.
Treat CO toxicity with HBO if the patient has neurologic symptoms, loss of consciousness, EKG changes, is pregnant, or has a CO level over 25% (some centers say 40%)
It is totally unclear from current data whether HBO is effective for CO poisoning. It may have a role in decreasing delayed neurologic sequelae.
The EP’s role is to identify CO poisoning and discuss management with a HBO center.
Jordan Body Packers , Body Pushers, and Body Stuffers
Packers swallow large amounts of well-packaged narcotics to smuggle thru customs
Body pushers conceal narcotics by placing them retrograde into the rectum or vagina
Body stuffers rapidly swallow unpacked drugs when they fear imminent arrest by police.
All these patients are initially unreliable because they are hiding narcotics.
As an emergency physcian caring for these patients you cannot force them to have imaging. If they refuse evaluation, they will need to remain in police custody and under observation in the ED until they have a bowel movement.
Sensitivity of x-rays for identifying body-packed narcotics ranges between 40-90%. Specificity is 93%.
Plain CT has a sensitivity and specificity of 97% for drug packets in GI tract.
Admit all confirmed body packers
Give them WBI or even just a laxative or cathartic to get the packets out.
Get confirmatory imaging (plain xray or CT?) to assure all packets are removed
Symptomatic patients should get exploratory lap to remove packets.
Chhabra Toxidromes
*Basically know your toxidromes. The big 4=Opioid, Sympathomimetic, Anticholinergic and Cholinergic.
Visual diagnosis
*Red cap mushrooms are amamita muscaria. These are hallucinogenic. Red top=hallucinogenic
*Death Cap mushrooms are aminita phylloides. These cause symptoms >6 hours after ingestion. These can kill you.
*Gyrometra mushrooms look like a brain (think gyri of the brain) but they can kill you as well. They get metabolized to the compound in rocket fuel.
The TOX EKG
A wide QRS is a marker for badness in toxicology. It is due to a depolarization/sodium channel dysfunction. Treat with 2 amps of NaHCO3.
Sodium channel problems get sodium bicarb.
Long QT interval (500ms) is a potassium channel problem. Treat with magnesium. Also give potassium up to the upper limits of normal.
Potassium channel problems get magnesium and potassium.
Fast atrial rhythms/Fast ventricular rhythms with AV block, bradycardia, afib with slow ventricular rate, and bidirectional ventricular tachycardia are all potential signs of digoxin poisoning. Treat tox patients with combined fast/slow problems on EKG with digibind.
Devgun Antidotes
Hydroxocobalamine has a deep purple color and can affect the colorimetric assays for creatinine and bilirubin. You can see a high creatinine and bilirubin in patients who have been treated with hydroxycobalamine.
Panel Discussion of Toxic Alcohol Management
Excellent discussion of management points of toxic alcohols
Use serum osmolality and osmolal gap as well as serum bicarb to raise your suspicion for toxic alcohol ingestion. You need to be aware that these labs are tricky with wide variation in normal values for patients and moving targets on both the osmolality and bicarb depending on time since ingestion.
Fomepizole basically prevents metabolism of toxic alcohols by competitively inhibiting alcohol dehydrogenase. It serves as a time bridge to allow you to set up dialysis to remove the toxic alcohol. A ph of 7.25 was recommended as a cut-off number indicating need for dialysis. This cut-off number is associated with increased incidence of renal failure and other morbidities. Another panel member made the point that if the patient still has an elevated osmolal gap that means they still have unmetabolized toxic alcohol on board and would benefit from dialysis.
There have been 50 episodes of mass methanol toxicity events in the last 15 years. In less developed countries or if fomepizole is not available, IV or oral ETOH is very effective to block alcohol dehydrogenase. You need to keep the blood alcohol level above 100.