USMLE Forum Archives - USMLE Step 1 - 3824
3824
babbu5508 - 10-21-10 01:35
A 34-year-old man with AIDS is brought to the emergency department with a severe form of shock characterized by fever, systemic hypotension, tachycardia, and depressed consciousness. Blood cultures are positive for Aspergillus. Which of the following factors is crucial in the pathogenesis of this form of shock?
Options:
A. C3a and C5a
B. Histamine
C. Interferon-V
D. Prostaglandin E
E. Tumor necrosis factor
babbu5508 - 10-21-10 01:35
A 34-year-old man with AIDS is brought to the emergency department with a severe form of shock characterized by fever, systemic hypotension, tachycardia, and depressed consciousness. Blood cultures are positive for Aspergillus. Which of the following factors is crucial in the pathogenesis of this form of shock?
Options:
A. C3a and C5a
B. Histamine
C. Interferon-V
D. Prostaglandin E
E. Tumor necrosis factor
The correct answer and explanation will be available after you answer.
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#2
Re: 3824
babbu5508 - 10-22-10 04:27 The correct answer is E. The form of shock presenting in this AIDS patient is septic shock, which has a high mortality rate (approximately 50%). Septic shock is usually due to sepsis from endotoxin-producing gram-negative bacteria, but may also result from gram-positive bacteria and fungi. Endotoxins produced by gram-negative bacteria are lipopolysaccharides (LPS) that may reproduce all of the hemodynamic effects of septic shock when injected into experimental animals. Macrophages respond to LPS by producing tumor necrosis factor (TNF), which, in turn, triggers a cytokine cascade (IL-1, IL-6 and IL-8, NO and PAF) leading to a number of potentially deleterious systemic responses. Depressed inotropism and generalized vasodilatation result in acute hypotension (shock), and widespread activation of the coagulation cascade may cause disseminated intravascular coagulation (DIC).
#7
Re: 3824 sudha2015 - 01-18-11 14:53 man with AIDS is brought to the emergency department with a severe form of shock characterized by fever, systemic hypotension, tachycardia, and depressed consciousness. Blood cultures are positive for Aspergillus.factors is crucial in the pathogenesis of this form of shockie tnf
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