Management of Iron Toxicity
Iron toxicity is determined by the amount of elemental iron (Fe) ingested. Examples of Fe formulations and the amount of elemental Fe contained in each formulation are listed in the table below (adapted from 1).
SimLIFE-EM Challenge: Add to the conversation
Debriefings in medical simulation are meant to be the bow on top of the gift that is medical simulation. It is the ultimate delicious dessert, served after a grueling dinner course. All analogies aside, debriefings are meant to drive home the teaching points, to gain a deeper understanding of medical resuscitation as a group, and create mental frameworks of the approach to various patients. But this is often easier described than actually done. We here at ALiEM paired with Dr. Henry Curtis to come up with a creative way of developing debriefing skills and gain deeper understanding of mental frameworks.
PV Card: Pediatric Ingestion Dose Thresholds for ED Referral
Clinical Toxicology has published guidelines for out-of-hospital management of 16 distinct overdoses and their dose thresholds, above which, pediatric patients should be referred to the Emergency Department for evaluation. Clinical Toxicology is the official journal of the American Academy of Clinical Toxicology (AACT, @AACTinfo), the American Association of Poison Control Centers (AAPCC, @AAPCC), and the European Association of Poisons Centres and Clinical Toxicologists (EAPCCT). There are two caveats to be aware of regarding these guidelines.
- They were developed between 2005 and 2007. New medications have been approved since that time and there may be more recent data available.
- As with any poisoning, dose is only one factor when determining disposition. Consideration should also be given to intent, underlying medical conditions, co-ingestion of other medications, presence of symptoms, and drug formulation.
This PV Card summarizes the pediatric ingestion dose thresholds for referral to an ED.
PV Card: Pediatric Dose Thresholds
Adapted from [1–16]
Go to ALiEM (PV) Cards for more resources.
Thanks to Zlatan Coralic, PharmD (@ZEDPharm) for his excellently detailed expert peer review and suggestions for revisions for this important card.
References
- Wax P, Erdman A, Chyka P, et al. beta-blocker ingestion: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2005;43(3):131-146. [PubMed]
- Caravati E, Erdman A, Christianson G, et al. Ethylene glycol exposure: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2005;43(5):327-345. [PubMed]
- Manoguerra A, Erdman A, Booze L, et al. Iron ingestion: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2005;43(6):553-570. [PubMed]
- Olson K, Erdman A, Woolf A, et al. Calcium channel blocker ingestion: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2005;43(7):797-822. [PubMed]
- Dart R, Erdman A, Olson K, et al. Acetaminophen poisoning: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2006;44(1):1-18. [PubMed]
- Scharman E, Erdman A, Wax P, et al. Diphenhydramine and dimenhydrinate poisoning: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2006;44(3):205-223. [PubMed]
- Manoguerra A, Erdman A, Wax P, et al. Camphor Poisoning: an evidence-based practice guideline for out-of-hospital management. Clin Toxicol (Phila). 2006;44(4):357-370. [PubMed]
- Caravati E, Erdman A, Scharman E, et al. Long-acting anticoagulant rodenticide poisoning: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2007;45(1):1-22. [PubMed]
- Chyka P, Erdman A, Christianson G, et al. Salicylate poisoning: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2007;45(2):95-131. [PubMed]
- Woolf A, Erdman A, Nelson L, et al. Tricyclic antidepressant poisoning: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2007;45(3):203-233. [PubMed]
- Nelson L, Erdman A, Booze L, et al. Selective serotonin reuptake inhibitor poisoning: An evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2007;45(4):315-332. [PubMed]
- Chyka P, Erdman A, Manoguerra A, et al. Dextromethorphan poisoning: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2007;45(6):662-677. [PubMed]
- Scharman E, Erdman A, Cobaugh D, et al. Methylphenidate poisoning: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2007;45(7):737-752. [PubMed]
- Cobaugh D, Erdman A, Booze L, et al. Atypical antipsychotic medication poisoning: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2007;45(8):918-942. [PubMed]
- Caravati E, Erdman A, Christianson G, et al. Elemental mercury exposure: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2008;46(1):1-21. [PubMed]
- Manoguerra A, Erdman A, Woolf A, et al. Valproic acid poisoning: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2008;46(7):661-676. [PubMed]
Anxiolytics and Hypnotics: Are They Doing Harm?
A patient presents to the emergency department complaining of increasing insomnia due to anxiety. She states that she is not actively suicidal nor homicidal but she has trouble “turning off her brain” at night in order to sleep and her insomnia is worsening her anxiety. She has a history of morbid obesity and smokes 1 pack of cigarettes per day. In order to help you consider writing her a prescription for 5 mg of zolpidem as you presume it to be a benign way to deal with her current sleep disorder. But what does the evidence say about these drugs and the risks of harm? (more…)
tPA Administration: Don’t Forget the Leftover Volume in the Pump Tubing
Whether alteplase (tPA) is given for ischemic stroke, pulmonary embolism, or STEMI, there is an important practical issue to be aware of during administration. Dr. Charles Bruen (@resusreview) published a great step-by-step pictorial tPA Mixing Tutorial. Once the tPA is mixed, it will invariably be infused via a smart pump through its corresponding tubing. At my institution we use Alaris® CareFusion smart pumps, through the principle applies irrespective of which brand pump is used.
PV Card: Local anesthetic toxicity calculations
Local anesthetics (LAs) are widely employed to achieve tissue infiltration, peripheral and regional anesthesia, and neuraxial blockades. Despite their well-established toxic dose limits, these agents continue to pose a substantial risk of morbidity and mortality due to local anesthetic toxicity and overdose.
For example, LAs and epinephrine account for a large proportion of medication errors resulting in adverse patient outcomes due to drug dosing miscalculations or errors converting between units. Dosage calculations vary by patient weight as well as by pharmacokinetics and pharmacodynamics of individual LA formulations. Further, non-standard units, additives (epinephrine), and varying concentrations among LAs complicate correct dosage derivations.
Toxicity nomogram
In an effort to curb calculation errors and avert LA toxicity, Williams and Walker derived a helpful nomogram1 to calculate the maximum, weight-based volume of commonly used LAs (lidocaine, prilocaine, bupivacaine, and ropivacaine). This nomogram was validated against a calculator in the original article. Please note that while this nomogram may aid in dosage verification, there is no substitute for a second, independent derivation of the total maximum dose using a different method, as an additional safeguard to prevent dosage error.
Local anesthetic toxicity presentation
LA toxicity presents clinically as a constellation of symptoms including, but not limited to, tinnitus, circumoral tingling, metallic taste, and dizziness. Severe manifestations include altered mentation, arrhythmias, and cardiovascular collapse. Management is predicated upon stopping the offending agent, providing supportive measures, and administering weight-based intravenous 20% lipid emulsion. The authors, Williams and Walker, derived a separate nomogram to guide treatment by calculating the appropriate weight-based lipid therapy, specifying the initial bolus amount, infusion rate, and total maximum dose of lipid emulsion.
Both the toxicity and lipid emulsion nomograms are displayed in this Paucis Verbis card.
Go to ALiEM (PV) Cards for more resources.
Ideal Body Weight (IBW) Calculation
The Devine formulation is the most commonly accepted calculation (most applicable for people at least 60 inches, or 5 feet, tall):
- IBW for men (kg) = 50 + 2.3 * (Height (in)-60)
- IBW for women (kg) = 45.5 + 2.3 * (Height (in)-60)
See the MDCalc calculator for IBW.
Reference
- Williams D, Walker J. A nomogram for calculating the maximum dose of local anaesthetic. Anaesthesia. 2014;69(8):847-853. [PubMed]
Atrial Fibrillation Rate Control in the ED: Calcium Channel Blockers or Beta Blockers?
Rate control with IV medications is recommended for atrial fibrillation in the acute setting in patients without preexcitation. This was a Class 1 recommendation (Level of Evidence B) per the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation [1]. What does the evidence say? Are calcium channel blockers or beta blockers better?