pathology of infectious disease - small group notes - julia

Question 1

what is a normal white cell count in CSF?

Answer 1

2-4 cells per mL of CSF

Question 2

what is purpura (review)?

Answer 2

rash due to bleeding into the skin not due to trauma - in the case in class, due to coagulation problem, which was indicated by long PT and PTT

Question 3

why would a patient with DIC have a low RBC count?

Answer 3

platelets are being used up/get stuck in the thromi in the small vessels

Question 4

why would a patient with DIC have greyish and pale fingers and toes?

Answer 4

• suggests poor/no circulation - due to microthrombi from DIC blocking small vessels in the extremities
• will eventually lead to infarction and necrosis of tissue - will turn black

Question 5

what is the consequence of DIC on the kidney and adrenal glands?

Answer 5

• swelling due to microthrombi in the glomeruli
• adrenal glands will be hemorrhagic

Question 6

what would a brain look like in a patient who died of meningitis?

Answer 6

• if the case went untreated for a long time, would have a creamy white coating (pus)
• if treated with antibiotics early though, would not have that coating, even if the case was fatal
• brain likely to be swollen
• likely areas of infarction due to DIC blocking small blood vessels and hypotension

Question 7

what causes waterhouse-friderichsen syndrome?

Answer 7

• overwelming bacterial infection
• commonly associated with neisseria meningitidis septicemia
• can also be caused by other highly virulent organisms such as pseudomonas, pneumoccocci, haemophius, influenzae or staphylococci

Question 8

what is the clinical presentation of waterhouse-friderichsen syndrome?

Answer 8

• infection/septicemia that rapidly progresses to hypotension and shock
• DIC with widespread purpura
• rapidly developing adrenocortical insufficiency associated with massive bilateral adrenal hemorrhage

Question 9

what are the possible causes of adrenalcortical insufficiency in waterhouse-friderichsen syndrome?

Answer 9

• overall due to hemorrhagic infarction
• direct bacterial seeding of small vessels in the adrenal - commonly associated with N. meningitidis
• DIC
• endotoxin-induced vascultitis
• hypersensitivity vasculitis

Question 10

what is DIC?

Answer 10

• complex systemic thrombohemorrhagic disorder
• intravascular fibrin
• consumption of procoagulatns and platelets
• aka consumptive coagulopathy

Question 11

what is DIC seen in association with?

Answer 11

• sepsis
• major trauma
• coagulopathy

Question 12

what is the mechanism by which DIC causes clinical problems?

Answer 12

• initiation of coagulation via endothelial injury or tissue injury
• subsequent release of procoagulant material in the form of cytokines and tissue factors
• in the setting of sepsis, neutrophils and their secretory products may promote platelet-mediated fibrin formation

Question 13

what are the clinical problems caused by DIC?

Answer 13

• generalized bleeding
• petechiae to exsanguinating hemorrhage or microcirculatory and macrocirculatory thrombosis
• hypoperfusion
• infarction
• end-organ damage

Question 14

what does the following lumbar puncture data indicate:

34 wbc (84% lymphs, 15% monos)

3000 RBCs

protein 222

Answer 14

• normal 0-7 WBC, all lymphs and/or monos, no polys; allow 1 wbc for every 1000 rbc
• so WBC high
• since there’s no neutrophils, not an acute inflammatory process - indicates chronic inflammation
• normal protein = 15-45
• high protein indicates damage to blood brain barrier

Question 15

what do high blood amylase levels indicate?

Answer 15

damage to acinar cells in pancreas