Review Question - QID 221208

This patient who presents with shoulder pain with any range of motion on postoperative day (POD) 11, most likely has an abscess given the well-healed incision sites.

The causes of postoperative fever can be divided into 6 distinct phases. During or immediately after surgery (POD 0), the most common causes are malignant hyperthermia or febrile non-hemolytic transfusion reactions. The most common causes of fever in the following 5 phases can be remembered using the “wind, water/womb, walking, wound, weird/wonder drugs” mnemonic. On POD 1-2, fever is generally caused by atelectasis (“wind”). On POD 3, fever is generally caused by a urinary tract infection (“water”) or endometritis (for obstetric cases, “womb”). Around POD 7, fever is caused by deep vein thrombosis or pulmonary embolism (“walking”). Wound complications, such as cellulitis, cause fever around POD 7. Finally, patients presenting with fever from POD 8-14 should prompt suspicion for abscesses or medication-induced fever.

Abdelmaseeh et al. review the causes, evaluation, and management of postoperative fever. They discuss how pneumonia, pulmonary embolism, wound infection, urinary tract infection, transfusion reaction, and sinusitis as important components of the differential diagnosis. They recommend using a systematic approach in order to narrow the differential and arrive at the right diagnosis.

Figure/Illustration A is a clinical photograph demonstrating a well-healing incision from a total shoulder arthroplasty (red circle). In the setting of a well-healing incision, a deep abscess is the most likely cause of a post-operative fever.

Incorrect Answers:
Answer 2: Malignant hyperthermia occurs soon after exposure to anesthetic agents. Patients present with dangerously high body temperatures that often exceed 105°F (40.6°C) and muscle rigidity. This patient’s fever developed on POD 11, well after exposure to anesthetics.

Answer 3: Pulmonary embolism can occur around POD 7 due to the period of relative immobility in the perioperative period. This can also occur for up to 5 weeks; however, it is relatively rare after upper extremity surgery as opposed to lower extremity surgery. This would present with fever, chest pain, tachycardia, and dyspnea with decreased oxygen saturation.

Answer 4: Urinary tract infection can occur around POD 3 and presents with fever, dysuria, and suprapubic tenderness. This patient has no urinary symptoms. Treatment of urinary tract infections is with antibiotics such as ceftriaxone or trimethoprim and sulfamethoxazole.

Answer 5: Wound cellulitis is a superficial infection that occurs around POD 7 and presents as fever and tenderness, erythema, and/or drainage around the wound site. This patient’s incisional sites are well-healed, making superficial wound infection unlikely.

Bullet Summary:
The most common causes of postoperative fever can be recalled using the 5 W’s: wind (atelectasis; days 1-2), water/womb (urinary tract infection, endometritis; day 3), walking (deep vein thrombosis, pulmonary embolism; day 5), wound (cellulitis, day 7), and weird/wonder drugs (abscess, medication fever; days 8-14).