Postoperative Fever

Question 1

Why is there such a huge risk of postoperative infection after a total joint replacement?

Answer 1

Prosthesis provides culture medium

Question 2

What are the differential diagnoses for a postoperative fever?

Answer 2

Infective
- UTI
- Pneumonia
- Wound infection
- Septic arthritis
Non-infective
- Transfusion
- DVT/PE
- Allergic reaction
- Medication reactions - rare

Question 3

What are the “big five” causes of postoperative fever?

Answer 3

Surgical site - late
IV sites - probably most common cause
UTI
Pneumonia
DVT - 5-7 days post-op

Question 4

What are the possible causes of fever between days 0 and 2 post-op?

Answer 4

Mild fever (<38)
- Common
- Likely inflammatory response to iatrogenic wound
Tissue damage and necrosis at operation site
Haematoma
Atelectasis
Specific infections related to surgery
Blood transfusion
Drug reaction
Infection prior to surgery
Malignant hyperthermia - very rare

Question 5

What are the possible causes of fever between days 3 and 5 post-op?

Answer 5

Bronchopneumonia
Sepsis
Wound infection
Drip site infection/phlebitis
Abscess formation
DVT
UTI

Question 6

What are the possible causes of fever after 5 days post-op?

Answer 6

Specific complications related to surgery
Wound infection
Distant sites of infection
DVT/PE
IV sites
Drug reactions
Other nosocomial infections, especially if in ICU

Question 7

What are the possible causes of fever one month after surgery?

Answer 7

Surgical site

Viruses and transfusion; eg: CMV

Question 8

What does spiking temperatures suggest?

Answer 8

Abscess

Question 9

How are IV sites, arterial lines, central lines, and drain sites assessed for possible source of postoperative fever?

Answer 9

Inspect all sites
Note date inserted
When were they changed?

Question 10

How are drain sites associated with postoperative fever?

Answer 10

May get infected

Indicator of deep infection - see purulent fluid

Question 11

What are the signs of central line-associated bloodstream infections?

Answer 11

Usually have no localising signs

Question 12

What should be assessed if you suspect a urinary tract infection as the source of the postoperative fever?

Answer 12

Was a catheter used? Is it still in situ?
Is the catheter blocked?
What colour is the urine?

Question 13

Does asymptomatic bacteraemia in catheterised patients need treatment?

Answer 13

No

Question 14

What signs can be seen in the chest that may indicate it as the source of the postoperative fever?

Answer 14

Crepitations

Dullness to percussion

Question 15

What assessment is done in the legs to determine if they could be the source of postoperative fever?

Answer 15

DVT
- Swelling
- Tender calf
- No signs, but high risk
Check thromboprophylaxis
- TEDS
- Clexane
- Pneumatic calf compressors
Investigate with US

Question 16

What is the usual anti-Staphylococcus cover in a postoperative patient?

Answer 16

First generation cephalosporin
Whether you do/don’t start with vancomycin depends on several factors
- Get ID input
- Consider vancomycin use

Question 17

What are the host risk factors for a surgical site infection?

Answer 17

Age
Obesity
Malnutrition
Diabetes
Steroids
Smoking
Infection at another site
Skin carriage of S aureus

Question 18

What are the environmental risk factors for a surgical site infection?

Answer 18

Type of surgery
Wound class
Surgical technique
Operation duration
Hair removal
Skin prep used
Hypothermia
Inadequate surgical Abx prophylaxis
- Choice
- Timing
Theatre traffic

Question 19

What should you consider in anyone with a positive blood culture for S aureus, especially if they’re not responding to antibiotics?

Answer 19

Endocarditis > do transoesophageal echocardiogram (TOE)

Question 20

Why is general anaesthesia preferred over spinal anaesthesia in a patient returning to theatre in the case of postoperative fever?

Answer 20

Spinal anaesthesia could introduce bacteria into CSF

Question 21

When does ventilator-associated pneumonia (VAP) develop?

Answer 21

More than 48 hours after intubation

Question 22

What are most cases of hospital acquired pneumonia related to?

Answer 22

Micro-aspiration

These patients often can’t cough properly because of neurological impairment

Question 23

What are the common organisms causing hospital acquired pneumonia?

Answer 23

Most commonly, aerobic Gram -ve bacilli
- E coli
- Klebsiella
- Enterobacter
- Pseudomonas
S aureus, including MRSA

Question 24

In whom are resistant pathogens more likely in the context of hospital acquired pneumonia?

Answer 24

VAP
ICU
Longer hospital stay
Previous Abx
Immunosuppression

Question 25

How can hospital acquired pneumonia be avoided?

Answer 25

Avoid excessive sedation
Mobilise - sit out of bed
Avoid H2 blockers and PPIs, unless ulcer risk