Are Toxidromes interesting? Yup.
I have always seen
Like the AEIOU mnemonic
for indications for emergent dialysis.
Another pearl I picked up today--end-stage renal patients, in addition to accumulating electrolyte disturbances like they were on the clearance rack, also have no way to eliminate fluids. Duh. So they show up on your doorstep in pulmonary edema from volume overload. BNP>1000 not uncommon for walkie-talkies, of course in addition to K+ over 7 and creatinines hovering around 10 as their blood becomes more urine than plasma.
Today we got notified of a 27 year old, coming in with an OD of, wait for it, wait for it...chloral hydrate.
Yeah. It was bad, too. Breathing at 6 per minute. Comatose, unresponsive to prehospital D50 and Narcan. 1/4 full 400ml bottle of chloral hydrate (AKA "Mickey Finns" when combined with alcohol, until recently used for conscious sedation in the ER, in the 50's for insomnia, and as a surgical anaesthic in the distant past. Why the hell does she have it?) on the stretcher. Pupils miotic and nonreactive. Hypotensive. BGM wnl. GCS 4. Intubate! 40 of etomidate and 200 of sux. Go!
Husband, the precipitant for said OD, comes into resuscitation bay amid the chaos. He has obviously been crying, but is looking for a fight, arms akimbo, looking for someone to blame, watching as 4 doctors, 3 nurses, an RT and 2 medical students (quiet, out of the way, and wanting to help, like good little med students) manage the resuscitation. Oh, hell, no. Get out! He, shocked and hurt, returns to ambulatory triage where his guilt and shame ambush him. The second year struggles not to intubate the esophagus, calling out, "I see vallecula, I don't, I do, I don't," etc.). Finally, tube is in, resps in lungs. Good. Meanwhile the nurse has been Foleyifying her; at this point this waif is completely exposed. I'm watching and discussing the toxidrome with CHILL-AS-FRICK ATTENDING, while GOOD-TEACHER-ATTENDING leads the code. Meanwhile, HOPELESS PRICK ATTENDING (my supervisor for the day, grr) sees my 18 yr old upper middle class, 5 months pregnant, strangely without prenatal care, with abdo pain (eventually a UTI, which I knew at the time). I turn to present, stop for a sec, and turn back to the much more interesting resuscitation. Our pride in our 2nd year resident for successfully intubating the pt melts as results to our shotgun initial orders come back. Blood gas--metabolic acidosis with adequate and expected respiratory compensation (pH 7.3, which I would judge as expected given the patient's crashing, and actually encouraging). Normal anion gap. Chem essentialy normal except for the aforementioned low bicarb. A pregnant pause. "What do we know about chloral hydrate tox?" says GOOD-TEACHER-ATTENDING, in more of a "I don't know" tone than "Do you know?" one. Um. I whip out my trusty palm. "hypotension. Seizures. Leukopenia. N/V, diarrhea, and sleep walking," I lamely mumble. I seize upon seizures, and fire off questions about sz at the paramedic. Nope. I return to my gigantic, expensive, and supposedly comprehensive palm programs futilely.
The precise mechanism of action of chloral hydrate is unknown but is confined to the cerebral hemispheres (Sifton, 1998). It is a general central nervous system depressant with minimal analgesic effects and a low ratio of anticonvulsant to sedative effects. Chloral hydrate decreases sleep latency and nighttime awakenings with minimal effects on REM sleep (Gilman et al, 1985).
The toxidrome involves respitory depression, life-threatenting arrhythmias, possible seizures, and coma or obtundation (half-life of 4-9 hours). Does it have tricyclic-like activity? According to my lit review (keyword: "chloral hydrate overdose" on medline), it acts like a benzo. In our case, given the development of wide-complex tachycardia, and reversal following 2 amps of sodium bicarb (an amp of socium bicarb is 3% sodium as compared with 0.9% in normal saline
Flumazenil is a competitive antagonist with specific action at the central benzodiazepine receptor. It is used when benzodiazepine intoxication is suspected. Its use has also been reported in cannabis intoxication, chloral hydrate overdose, hepatic encephalopathy, and alcohol intoxication.