Epinephrine is effective in helping reverse the adverse effects of anaphylaxis. It is the drug of choice because it causes bronchodilation and vasoconstriction to improve respiratory effort and improve blood pressure. What other effect does epinephrine have on the patient's body during an anaphylactic reaction?

Correct Answer: A

Rationale: The correct answer is A: It reduces the release of chemical mediators from the mast cells. Epinephrine acts on adrenergic receptors to inhibit mast cell degranulation, reducing the release of histamine and other inflammatory mediators that contribute to anaphylaxis. This helps to prevent further systemic allergic reactions and stabilize the patient. Choice B is incorrect because while epinephrine does help reduce the overall inflammatory response by stabilizing mast cells, it is not the primary mechanism of action. Choice C is incorrect as epinephrine primarily causes an increase in heart rate through its positive inotropic and chronotropic effects on the heart, rather than peripheral vasoconstriction. Choice D is incorrect as while epinephrine does cause vasoconstriction, it is mainly focused on improving blood pressure and systemic vascular resistance rather than reducing itching.

Correct Answer: B

Rationale: The correct answer is B: Direct pressure on the wound. Direct pressure is the initial step to control bleeding from a wound. It helps to compress blood vessels and stop bleeding. A tourniquet (A) is not necessary and can lead to complications if used inappropriately. Packing the wound with gauze (C) may not be effective in controlling bleeding from a large wound and can cause further trauma. Direct pressure on the femoral artery at the groin (D) is not recommended as a primary measure and can be difficult to perform effectively in an emergency setting.

Correct Answer: A

Rationale: The correct answer is A: "The trachea is relatively short." During infant endotracheal intubation, the trachea in infants is shorter compared to adults, making it easier for the endotracheal tube to be inadvertently inserted into the right or left mainstem bronchus. This is due to the anatomy of infants where the distance from the vocal cords to the mainstem bronchi is shorter, increasing the risk of bronchial intubation. Summary: B: The distance from the lips to the larynx being short is not directly related to the risk of bronchial intubation. C: The use of tubes without cuffs is not a primary factor leading to bronchial intubation. D: The angulation of the mainstem bronchi is not a significant factor in the increased risk of bronchial intubation during infant endotracheal intubation.

Correct Answer: A

Rationale: The correct answer is A: "Perform needle cricothyroidotomy with jet insufflation". In this scenario, the infant is in respiratory distress with unsuccessful intubation. Needle cricothyroidotomy is the most appropriate procedure as it provides a rapid and effective way to establish a patent airway in an emergency. Jet insufflation helps provide oxygenation. Administering heliox and racemic epinephrine (B) is not appropriate for this immediate airway management situation. Nasotracheal intubation (C) is not recommended in the case of failed oral intubation and the urgency of the situation. Surgical cricothyroidotomy (D) is more invasive and time-consuming compared to needle cricothyroidotomy in this critical condition.

Correct Answer: A

Rationale: The correct answer is A: "Early gastric decompression is important." In pregnant patients following blunt trauma, there is a risk of delayed gastric emptying and aspiration due to compression of the stomach by the gravid uterus. Early gastric decompression helps to prevent aspiration pneumonia and improve respiratory outcomes. Choice B is incorrect because a hemoglobin level of 10g/dl does not specifically indicate recent blood loss in a pregnant patient. Choice C is incorrect as pregnant patients can have a normal or exaggerated CVP response to volume resuscitation. Choice D is incorrect as a lap belt can cause direct pressure on the gravid uterus, increasing the risk of fetal injury during blunt trauma.