PUO / Influenza / HAI Flashcards
What is a PUO
> 3 febrile episodes
1 week of investigation
What is a fever
Elevation of temp above 37
Clinical cut off = 38
What causes a PUO
Infection Malignancy Inflammatory Drugs Venous thrombosis Neutropenia HIV associated Tropical disease
What infections tend to cause
Abscess
TB
What are inflammatory causes of PUO
SLE
Vasculitis
IBD
What is a neutropenic fever
Undiagnosed fever in patient with low neutrophils <500
What is HIV associated fever caused by
Commonly mycobacterium TB / avium
When is tropical disease unlikely
If fever <21 days
What tropical diseases cause fever
Malaria
Tyhpoid
Dengue
What is important in the Hx of fever
Pattern Travel Contact Food Sexual FH - age on onset Occupation PMH / drug / surgery
What do you ask in travel HX
Location Risk activities Purpose of trip Accommodation Vaccine Malaria prophylaxis - always Sexual contacts
What investigation should you do for fever
EXAM - REPEAT FBC, U+E, LFT, CRP Blood film Blood culture Urine / stool Urinanalysis CXR USS abdo
When do you do cultures
At time of fever
What are further tests that can be done if Dx still unknown
Blood culture / serology for tropical disease Bone marrow ECHO Biopsy - if headache TB test BBV Renal biopsy / USS Auto Ab CT PET
When do you do ECHO
New murmur
When do you do bone marrow
Malignancy
Leishmaniosis
When do you do renal biopsy
Haematuria
How do you treat PUO
Steroids if suspect vasculitis
Anti-TB
Steroids / NSAIDs - may respond even if no Dx
When is TB unlikely
If no response after 2 weeks of chemo
What is a fabricated fever
Fever is real but self induced
Multiple organisms on blood culture
What is a pyrogen
Substance which causes fever
Endogenous - cytokine
Exogenous - endotoxin
What do pyrogens do
Act on hypothalamic thermoregulatory centre Increases set point Vasoconstriction Decreased heat loss Causes fever
What is a HAI
Infection arise >48 hours after admission or discharge
What are common sources of HAI
Catheter Surgical site Intubation Central lines Break in skin
What does HAI transmit
Direct contact Respiratory Faecal - oral Penetrating injury Disruption bacteria / host = most common
Microbial RF in hospital
Increased resistance
Increased transmission
What are host RF
Devices Ax Wounds Immunosuppression Age Overcrowding