Differential Diagnosis for 78F Day 6 post total shoulder replacement

• Single most likely diagnosis
  • Constipation with opioid-induced worsening pain: The patient is on post-operative day 6 after a major surgery, and opioids are commonly used for pain management. Constipation is a well-known side effect of opioid use, and worsening pain could be due to constipation or inadequate pain control.
• Other Likely diagnoses
  • Surgical site infection: Although it's early for a surgical site infection, it's possible, especially if the patient has been experiencing worsening pain.
  • Deep vein thrombosis (DVT): Immobility after surgery increases the risk of DVT, which can cause pain.
  • Pulmonary embolism (PE): Similar to DVT, immobility after surgery increases the risk of PE, which can cause sudden worsening of pain and increased lactate levels.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Sepsis: An elevated lactate level of 2.4 is concerning for sepsis, which can be caused by a variety of sources, including surgical site infection, pneumonia, or urinary tract infection.
  • Myocardial infarction: Although less likely, myocardial infarction can cause worsening pain and increased lactate levels.
  • Spinal epidural hematoma: A rare but potentially devastating complication of surgery, especially if the patient has been on anticoagulation therapy.
• Rare diagnoses
  • Adhesive capsulitis (frozen shoulder): Although unlikely to cause acute worsening of pain, it's a possible complication of shoulder surgery.
  • Nerve injury: Direct nerve injury during surgery or compression from a hematoma can cause worsening pain.
  • Osteonecrosis: A rare complication of shoulder replacement surgery, but unlikely to cause acute worsening of pain on post-operative day 6.