As we are now into the winter months, exposures to ethylene glycol (antifreeze) and methanol (windshield washer fluid) increase. Here is a good mnemonic for sorting through an anion gap metabolic acidosis:
C – cyanide, carbon monoxide
A – alcoholic ketoacidosis, acetaminophen (massive OD)
T – toluene (chronic from glue sniffing)
M – methanol, metformin
U – uremia
D – diabetic ketoacidosis
P – propofol infusion syndrome, propylene glycol, paraldehyde
I – iron, isoniazid, ibuprofen (massive OD)
L – lactic acidosis
E – ethylene glycol
S – salicylates, starvation ketoacidosis
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The newest antidote for cyanide poisoning, hydroxocobalamin, has several advantages over the older Cyanide Antidote Kit (amyl nitrite, sodium nitrite, sodium thiosulfate). Hydroxocobalamin works rapidly, does not induce methemoglobinemia, and does not cause vasodilation/hypotension.
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Zanamivir (Relenza) is another neuraminidase inhibitor effective against influenza strains A and B. We are currently reserving its use for patients with H1N1 that may develop resistance to oseltamivir (Tamiflu) since it has been effective in these situations with past influenza strains.
A 34 y/o m presents to the ED agitated and combative with the following vitals signs: T 104.6, P 136, BP 198/124. His urine toxicology screen is positive for amphetamines.
Most hand sanitizers contain ethanol, while some contain isopropyl alcohol. The concentration of alcohol in these products varies from 45% to 95%, with the most commonly used products containing 62%. How much would a 15 kg child have to ingest to obtain a blood alcohol concentration of 100 mg/dL (or 0.1%)?
Assuming a volume of distribution of 0.6 L/kg and 100% bioavailability, only 15-20 mL is required to produce this toxic level. That is equivalent to 3-4 teaspoons or approximately 8-10 “squirts” of hand sanitizer!
One of the treatment options for NYHA class III and IV pulmonary hypertension is prostanoids. All of the prostanoid formulations have the limitations of a short half-life and a heterogeneous response to therapy. Because the drugs need to be given by continuous infusion, patients may present to the ED due to pump failure. Sudden cardiopulmonary collapse can occur with infusion interruption. Here are some important points to remember regarding kinetics:
One of the options in our armamentarium prior to inserting an NG tube or performing a non-emergent nasotracheal intubation is nebulized lidocaine. However, the total dose is always a concern with this anesthetic agent before we have to worry about toxicity such as lightheadedness, tremors, hallucinations, seizures, and cardiac arrest. Here are some points to remember:
Patients who present to the ED with an elevated INR due to vitamin K antagonists many times do not need to be reversed. Simply holding a dose is all that is usually necessary for patients with an INR < 9. Fortunately, guidelines published in CHEST are available to help guide management.
Reference:
Ansell, J, Hirsh, J, Hylek, E, et al. Pharmacology and management of the vitamin K antagonists: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest 2008; (6 Suppl):160s.
Your patient presents unresponsive with an empty bottle of alprazolam (Xanax). You order a urine and blood toxicology screen. The blood comes back negative for benzodiazepines but the urine test is positive. How do you interpret this result?
Overdoses of insulin glargine (Lantus) are rarely reported in the literature. In fact, there are only 6 case reports. We recently had a patient in our ED who was hypoglycemic from insulin glargine. The hypoglycemic episode was quite prolonged (> 24 hours) in the ED before being the patient was transferred to the MICU. Here are a few points to remember:
Add metoclopramide (Reglan) to the laundry list of medications with black box warnings from the FDA. Why was a black box warning added?
You have a 44 y/o female patient with an arterial line monitoring her blood pressure which is reading 302/156 mm Hg. Her heart rate is 140 bpm. Her history reveals she is taking a monoamine oxidase inhibitor (MAOI) and has inadvertantly ingested tyramine at her friend's cheese/wine party. What do you do?
A few previous pearls have touched on identifying drugs that cause QT prolongation. In our patient population, methadone is one of the more common causes of drug-induced prolonged QT syndrome. Of 692 physicians surveyed (35% family practitioners, 25% internests, 22% psychiatrists, and 8% self-identified addiction specialists) only 41% were aware of methadone's QT-prolonging properties and just 24% were aware of methadone's association with torsade de pointes.
Now that you know, what do you do when a patient on methadone presents with a QTC of 580 msec and intermittent runs of vtach and torsade de pointes?
The answer is... the exact same thing you would do with any other patient who presents this way, regardless of the cause.
Buprenorphine, an alternative to methadone, is not associated with prolonged QT syndrome.
A search of the toxicology literature will reveal that naloxone has been tried in many different overdose situations. It is thought that the endogenous opioid system mediates several physiologic and pharmacologic pathways.
Bottom line: In none of these instances was improvement as dramatic or consistent as in the reversal of the toxic effects of an opioid. Naloxone can certainly be tried in non-opioid overdoses but should not be considered a first-line antidote. The most benefit appears to be with clonidine.
How many times have you had a patient with an allergy to codeine described as stomach upset? Or how about a rash with morphine (probably secondary to histamine release)? True anaphylactic reactions to opioids are very rare (< 1%). But what happens when you have a patient with a true allergy, but still need to give an opioid? No problem, you just need to choose one that is structurally different.
All of the group 1 and 2 agents are structurally very similar to each other and should not be given if a true allergy exists to any other natural or semi-synthetic derivative. Group 3 agents have structures different enough that they can be given to a patient intolerant to the natural or semi-synthetics without fear of cross reactivity. They are also very different from others in this same group.
Methods: A large retrospective case series evaluated 121 children under 6 years old with hypoglycemia from a sulfonylurea ingestion.
Results:
Authors' Conclusion: Octreotide administration decreases the number of hypoglycemic events and increases blood glucose concentrations in children with sulfonylurea ingestion.
