What is the most likely diagnosis for a postoperative patient with fever, tachycardia, leukocytosis, and hypotension following a laparoscopic cholecystectomy?

Postoperative SIRS Following Laparoscopic Cholecystectomy

This patient most likely has SIRS (Systemic Inflammatory Response Syndrome), which is the expected physiologic response to surgical trauma in the early postoperative period, particularly within the first 48 hours after laparoscopic cholecystectomy. 1

Clinical Reasoning

This patient meets at least 3 of 4 SIRS criteria: fever (38.6°C, >38°C), tachycardia (116 bpm, >90 bpm), leukocytosis (stated), and hypotension (BP 90/60, MAP approximately 70 mmHg). 1 The presence of ≥3 SIRS criteria in the early postoperative period strongly supports this diagnosis. 1

Why SIRS is Most Likely:

• SIRS occurs in approximately 63% of patients after laparoscopic cholecystectomy and represents the normal inflammatory response to surgical trauma rather than infection. 1

• The timing is critical: This patient is in the immediate postoperative period. During the first 48 hours after surgery, SIRS commonly results from the stress of surgery and pneumoperitoneum, not infection. 2, 1

• Surgical site infections rarely occur within 48 hours postoperatively, with the rare exceptions being group A streptococcal or clostridial infections. 1, 3 The wound shows only "slight erythema" without purulent drainage, which is insufficient for SSI diagnosis. 1

Excluding Other Diagnoses:

Surgical Site Infection (Option C) is unlikely because:

• SSI requires purulent drainage, positive culture, or significant local signs requiring surgical opening of the wound. 1
• Slight erythema alone without pus formation does not meet SSI criteria. 1
• The timing is too early for typical SSI development. 3

UTI (Option B) is less likely because:

• No urinary symptoms are mentioned in the clinical presentation. 3
• While UTI should be considered in the differential, the constellation of findings with hypotension and meeting full SIRS criteria points more toward systemic inflammatory response. 1

Thrombophilia (Option A) does not explain the clinical picture:

• This would not account for fever, leukocytosis, and the full SIRS presentation. 1

Critical Management Considerations

However, this patient requires urgent evaluation and monitoring because:

• The presence of hypotension (BP 90/60) with SIRS criteria raises concern for progression to septic shock. 1 Mean arterial pressure should be calculated and aggressive fluid resuscitation initiated if needed. 1

• A structured bedside assessment must be performed immediately to determine if the patient is hemodynamically stable or unstable, assess for end-organ dysfunction, and guide appropriate treatment. 2

• Passive leg raise (PLR) testing should be considered to determine if hypotension is preload-responsive (only 50-54% of postoperative hypotensive patients respond to fluid). 2 If PLR does not correct hypotension, vasopressor or inotropic support may be required rather than additional fluid. 2

Red Flags Requiring Immediate Action:

Do not dismiss this as "normal postoperative fever" when accompanied by hypotension and tachycardia. 1 While SIRS is common, the combination with hemodynamic instability warrants:

• Abdominal CT scan to detect fluid collections, biloma, or ductal dilation (bile duct injury complications). 2, 1
• Liver function tests and inflammatory markers (CRP, PCT, lactate) to evaluate severity and monitor response. 2
• Thorough wound examination for purulent drainage, extensive erythema (>5 cm from incision), or signs of toxic shock syndrome. 1, 3 If TSS is suspected, open the wound immediately and begin anti-staphylococcal therapy. 4
• Transfer to higher level of care if the patient shows signs of end-organ dysfunction or remains unstable. 2

Common Pitfalls to Avoid:

• Do not assume SSI based solely on slight erythema without purulent drainage in the first 48 hours. 1, 3
• Do not delay investigation when hypotension accompanies fever and tachycardia, even if SIRS is the most likely diagnosis. 1
• Do not automatically give fluid boluses without assessing fluid responsiveness, as approximately 50% of hypotensive postoperative patients require vasopressor/inotropic support rather than preload augmentation. 2