What is the likely cause of fever in a female of reproductive age, 10 days post-surgery for an ectopic pregnancy and fallopian tube removal, who was discharged from hospital after 7 days?

Likely Cause of Fever 10 Days Post-Ectopic Surgery

At 10 days post-surgery for ectopic pregnancy with fallopian tube removal, the most likely cause of fever is a surgical site infection, followed by urinary tract infection if a catheter was used, or other infectious complications such as pelvic abscess or retained products.

Timing and Probability of Infection

• Fever occurring at postoperative day 10 is highly likely to represent an infectious cause rather than benign inflammatory response, as the normal surgical inflammatory response resolves within 48-72 hours 1
• After 96 hours (day 4) post-surgery, fever is equally or more likely to be caused by infection, and by day 10, infectious etiology becomes the predominant concern 1, 2
• Only about 40% of fever episodes in hospitalized patients are caused by infection, but fever continuing more than three days after surgery should raise strong suspicion of persistent illness or new complication 3

Most Likely Causes in This Clinical Context

Surgical Site Infection (Primary Concern)

• Surgical site infections are the leading consideration at this timepoint, particularly given the pelvic/abdominal nature of the surgery 1, 2
• For operations on the female genital tract, infections often involve both aerobic and anaerobic bacteria 1
• The incision must be inspected for purulent drainage, spreading erythema (>5 cm from incision), induration, warmth, tenderness, swelling, or any necrosis 1, 2

Pelvic Abscess or Deep Infection

• Given the gynecologic nature of the surgery (ectopic pregnancy with tube removal), pelvic abscess formation is a significant concern at this timepoint 1
• These may not be evident on superficial wound examination and may require imaging if clinical suspicion is high 1

Urinary Tract Infection

• Duration of catheterization is the single most important risk factor for UTI development 2, 4
• If a urinary catheter was in place for >72 hours during the hospitalization, UTI becomes a strong possibility 1

Thromboembolic Disease

• Maintain high suspicion for deep venous thrombosis or pulmonary embolism in this patient given risk factors including recent pelvic surgery, potential oral contraceptive use (reproductive age female), and sedentary status post-discharge 1, 2

Retained Products or Endometritis

• In the context of ectopic pregnancy surgery, consider retained gestational tissue or endometritis as potential causes 1

Immediate Evaluation Required

Wound Examination (First Priority)

• Remove any dressings and thoroughly inspect the surgical incision for purulent drainage, erythema, induration, warmth, tenderness, or swelling 2, 4
• If erythema extends >5 cm from incision with induration or any necrosis is present, immediate intervention with wound opening, empiric antibiotics, and dressing changes is required 1, 2
• Obtain Gram stain and culture of any purulent drainage before starting antibiotics 1, 4

Urinalysis and Culture

• Perform urinalysis and urine culture, especially if catheter was in place for >72 hours or if urinary symptoms are present 1, 4

Blood Cultures

• Obtain blood cultures if temperature ≥38°C with systemic signs of infection beyond isolated fever (hemodynamic instability, altered mental status, signs of bacteremia/sepsis) 1, 2, 4

Imaging Considerations

• Chest radiograph is indicated only if respiratory symptoms develop, not for isolated fever 1, 2
• CT imaging of the pelvis/abdomen should be considered in collaboration with surgery if initial workup does not identify the source, particularly to evaluate for pelvic abscess or fluid collection 1
• Pelvic ultrasound may be useful given the gynecologic nature of the surgery and to evaluate for retained products or abscess 1

Empiric Antibiotic Coverage (If Infection Confirmed)

• For infections related to female genital tract surgery, empiric coverage must include both aerobic and anaerobic bacteria 1, 2
• Recommended regimens include: cephalosporin + metronidazole, levofloxacin + metronidazole, or carbapenem 1, 2
• Do not start antibiotics before obtaining appropriate cultures unless patient shows signs of severe sepsis or hemodynamic instability 4

Red Flags Requiring Immediate Escalation

• Hemodynamic instability (hypotension, tachycardia out of proportion to fever) 1, 2
• Altered mental status 1, 4
• Respiratory compromise 4
• Signs of severe infection or sepsis 2
• Severe systemic toxicity or organ dysfunction 1

Common Pitfalls to Avoid

• Do not assume atelectasis as the cause—atelectasis should be a diagnosis of exclusion and does not typically cause fever at this timepoint 1, 4
• Do not delay investigation because other findings seem unremarkable—isolated fever on day 10 warrants thorough evaluation 4
• Do not start empiric antibiotics before obtaining cultures unless clinically unstable, as this compromises diagnostic accuracy 4
• Do not overlook thromboembolic disease in a young female post-pelvic surgery 1, 2