Specialized Medical Emergencies Flashcards

A 28-year-old female is found unconscious after a suspected intentional overdose. Her ECG shows a heart rate of 120, a QRS complex of 140 ms, and a prominent terminal R wave in lead aVR. Which medication overdose is most likely responsible for these findings, and what is the primary treatment?

Answer: Tricyclic antidepressant (TCA) toxicity; Sodium Bicarbonate

The classic ECG findings of sinus tachycardia, a widened QRS complex (>100 ms), and a prominent terminal R wave in aVR are pathognomonic for significant cardiotoxicity from a tricyclic antidepressant overdose. [3, 9, 21] This toxicity is caused by the blockade of fast sodium channels in the myocardium. Sodium bicarbonate is the primary antidote; it increases the extracellular sodium concentration to overcome the channel blockade and increases serum pH, which reduces the affinity of the TCA for the sodium channels. [15, 18]

A flight crew is transporting a 34-week pregnant female with severe preeclampsia who begins to have a tonic-clonic seizure. Which of the following is the first-line medication for seizure control in this eclamptic patient?

Answer: Magnesium Sulfate

Magnesium sulfate is the drug of choice for both the prevention and treatment of eclamptic seizures. [1, 14, 19] It acts as a central nervous system depressant and membrane stabilizer to control and prevent further seizure activity. While benzodiazepines like lorazepam may be used for refractory seizures, magnesium sulfate is the initial and primary intervention recommended by major clinical guidelines. [12, 32]

You are transporting a hiker found unconscious after being lost in the mountains during winter. His core temperature is 27°C (80.6°F) and the cardiac monitor shows ventricular fibrillation. According to advanced life support guidelines for severe hypothermia, what is the most appropriate action?

Answer: Attempt a single defibrillation, then focus on high-quality CPR and active rewarming, withholding further shocks and drugs until the core temperature is >30°C.

In severe hypothermic cardiac arrest (core temperature <30°C or 86°F), the myocardium is extremely cold and irritable, making it refractory to both medications and repeated electrical shocks. [2] Current guidelines recommend attempting a single defibrillation for a shockable rhythm. If unsuccessful, the focus should shift to continuous high-quality CPR and rapid, active core rewarming. Further defibrillation attempts and the administration of IV drugs are typically withheld until the core temperature has been raised to at least 30°C (86°F), as drug metabolism is slowed and repeated shocks are unlikely to be effective. [2, 31]

Which of the following laboratory and clinical findings is most characteristic of Diabetic Ketoacidosis (DKA) as opposed to Hyperosmolar Hyperglycemic State (HHS)?

Answer: Significant metabolic acidosis with an elevated anion gap.

The defining feature that distinguishes DKA from HHS is the presence of significant ketosis and a subsequent anion gap metabolic acidosis. [4, 23] In DKA, an absolute insulin deficiency leads to lipolysis and the production of acidic ketone bodies. HHS is characterized by a relative insulin deficiency, which is enough to prevent significant ketosis but not enough to prevent extreme hyperglycemia, leading to more profound dehydration and hyperosmolality. [10, 16, 27]

A 22-year-old male with a history of sickle cell disease is being transported with acute-onset chest pain, fever, and a new infiltrate on his chest x-ray. He is hypoxic with an SpO2 of 88% on a non-rebreather mask. This clinical picture is most consistent with which life-threatening complication?

Answer: Acute Chest Syndrome (ACS)

Acute Chest Syndrome (ACS) is a form of acute lung injury and a leading cause of death in patients with sickle cell disease. [35] It is clinically defined by the presence of a new pulmonary infiltrate on chest x-ray combined with fever and/or respiratory symptoms such as chest pain, cough, or hypoxia. [11, 30, 34] While a vaso-occlusive crisis causes severe pain, the combination of respiratory symptoms and a new infiltrate specifically points to ACS.

A farm worker presents with diaphoresis, lacrimation, urination, defecation, and pinpoint pupils. He has copious bronchial secretions and is bradycardic. This presentation is classic for exposure to which class of toxin?

Answer: Organophosphates

This patient is exhibiting signs of a cholinergic crisis, caused by excessive acetylcholine stimulation. Organophosphates, commonly found in insecticides, are acetylcholinesterase inhibitors. They prevent the breakdown of acetylcholine, leading to its accumulation and the overstimulation of muscarinic and nicotinic receptors. [6, 24] The symptoms can be recalled using mnemonics like DUMBELS (Diaphoresis/Diarrhea, Urination, Miosis, Bradycardia/Bronchorrhea, Emesis, Lacrimation, Salivation) or SLUDGEM. [13, 26, 29]