Sub-phrenic abscess

Question 1

You are asked by the nursing staff on the surgical ward to review a 68 year old woman with a swinging fever and right shoulder tip pain. She underwent a laparotomy for perforated peptic ulcer seven days earlier. What is the likely diagnosis and appropriate treatment?

Answer 1

Impression
Given the post-op timeframe in constellation with symptoms; namely swinging fever and shoulder tip pain, am concerned about a sub-phrenic abscess that has formed as post-op complication.

DDx

• Phlegmon
• Bowel perf and pneumoperitoneum
• hepatitis, pancreatitis, free abdo fluid
• REDS: ACS, PE, pleural effusion

Goals

• Targeted Hx/Ex/Ix to rule out red flag differentials
• US to gauge size and location of abscess/collection, likely for percutaneous drainage and antibiotics

Question 2

Sub-phrenic abscess - Assessment

Answer 2

Assessment

Take A to E approach to ensure HD stability, rule out systemic signs of infection/illness

Question 3

Sub-phrenic abscess - History

Answer 3

History
- sx: swinging fevers, R shoulder tip pain, developed 5-7 days post-op. Is hardest region of abdomen to effectively wash out. Any pain on breathing?
- REDS: chest pain, SOBOE, dyspnoea, diaphoresis, other sites of pain (abdo, etc), persistent fevers, chills, sweats, etc
- other: low mobilisation
- Check medications chart and PRNs + medical management plan in place currently
RISKS: immunocompromised: steroids, DM, etc

Question 4

Sub-phrenic abscess - Examination

Answer 4

Examination

• General appearance
• Vitals, review nursing obs
• Abdo exam: rule out peritonism, tenderness, organomegaly
• Review surgical site for signs of infection +/- lines, drains
• Cardioresp examination

Question 5

Sub-phrenic abscess - Investigations

Answer 5

Investigations
Diagnostic
- CT abdo with IV contrast for abscess identification
- ABdo US
- MCS on percutaneous drainage sample (if possible)

• Bloods: UEC, LFT, CRP, cultures, lipase
• Imaging: CXR for resp DDX

Question 6

Sub-phrenic abscess - Management

Answer 6

Management
- consult gen surgery team
- US-guided drainage;
   o percutaneous
   o endoscopic
   o surgical
- antibiotics: Gent + amp + metro if not already on, switch to directed once sensitivities return. 5 days of treatment if source is controlled and no more symptoms. Longer if cannot drain or unresolving symptoms.