Pyrexia

Question 1

What is pyrexia?

Answer 1

Raised body temperature >37.5c

Question 2

What is the most common cause of post-op pyrexia? What helps indicate the underlying cause of this?

Answer 2

Infection
Day 1-2 post-op: consider respiratory, wind
Day 3-5: consider UTI, water
Day 5- 7: consider surgical site infection or abscess/collection formation, wound
Any day - infected IV lines or central lines

Question 3

What are other causes of post-op pyrexia apart from infection?

Answer 3

Iatrogenic - drug-induced reaction or transfusion reaction
Venous thromboembolism - PE/DVT but rare to cause fever
Secondary to prosthetic implantation
Pyrexia of unknown origin

Question 4

What is pyrexia of unknown origin?

Answer 4

Recurrent fever (>38c) perisisting for >3 weeks without obvious cause, despite >1week of inpatient investigation

Causes include - unknown source, malignancy, connective tissue disorder or vasculitis

Question 5

What investigations for pyrexia?

Answer 5

Septic screen
Blood tests - FBC, CRP, U&E
Urine dipstick
Cultures - blood, urine, sputum, wound swab
Imaging - CXR

Question 6

What is the management for pyrexia?

Answer 6

Empirical antibiotics
Anti-pyeretics and analgesia for support
Hydration - commence fluid balanced
Low threshold for sepsis

Question 7

What are example empirical antibiotic regime for:
LRTI
Lower UTI
Upper UTI
Surgical site/cellulitis
IV line
Intra-abdominal infection
Septic arthritis
Unknown

Answer 7

LRTI - co-amoxiclav 5 days
L UTI - TRimethoprim 3 days
Upper UTI co-amoxiclav 14 days
Surgical site - flucloxacillin 5 days
IV line - flucloxacillin 5 days
Intra-abdominal Cefuroxime+ metronidazole
Septic arthritis - flucloxacillin 
Unknown Cefuroxime + metronidazole +gentamycin