A high clinical suspicion should be maintained even in patients who would traditionally be considered low-risk. The EP should have a low-threshold for ECG, cardiac biomarker testing, and stress testing for SLE patients presenting with chest pain. The treatment of ACS in SLE patients is the same as in the general population.
Libman-Sacks Endocarditis. A sterile, fibrinous valvular vegetation, Libman-Sacks endocarditis is unique to patients with SLE. When present, patients usually develop a subacute or chronic onset of dyspnea or chest pain. However, patients may become acutely ill if they develop severe valvular regurgitation. Additionally, the valve damage from Libman-Sacks endocarditis can predispose patients to developing infective endocarditis.20
Hematological Complications
Common Complications
Patients with SLE commonly have mild-to-moderate leukopenia (especially lymphopenia), anemia, and thrombocytopenia. This may be related to the disease process or may be secondary to prescribed medications. A comparison to recent baseline laboratory studies should be sought if there is suspicion for new or worsening cytopenia.
Antiphospholipid Syndrome. Nearly 40% of SLE patients also have APS, which is defined by a clinical history of thrombosis in conjunction with one of the antiphospholipid antibodies (anticardiolipin, anti-beta-2-glycoprotein, lupus anticoagulant). Antiphospholipid syndrome causes both venous and arterial thrombosis and may be associated with recurrent miscarriage. Acute thrombotic events should be treated with heparin or enoxaparin and transitioned to warfarin. The new generation of direct oral anticoagulants have not been well studied in APS, though, multiple small case series suggest a higher thrombotic risk with these drugs than with warfarin.23Patients who have recurrent venous thromboembolism, or who have any arterial thromboembolism should be on lifelong anticoagulation therapy.2
Emergent Complications
Thrombocytopenia. Severe thrombocytopenia or hemolytic anemia can be life-threatening, and often requires inpatient admission for immunosuppressive therapy, monitoring, and supportive care.
Catastrophic Antiphospholipid Syndrome. This condition should be suspected in patients with SLE who present with multiple sites of thrombosis or new multi-organ damage. Catastrophic APS (CAPS) may occur in SLE patients who have no prior history of APS. Since the mortality rate for CAPS approaches 50%, these patients require anticoagulation, immunosuppressant therapy (high-dose corticosteroids, cyclophosphamide, and/or plasma exchange), and admission to the ICU.24
Gastrointestinal Complications
Common Complications
Intestinal Pseudo-obstruction. Dysphagia related to esophageal dysmotility is present in up to 13% of SLE patients.25 Intestinal pseudo-obstruction may be seen in SLE patients, and is characterized by symptoms of intestinal obstruction caused by decreased intestinal motility, rather than from mechanical obstruction. Presenting symptoms may be acute or chronic, and include nausea, vomiting, and abdominal distension. Abdominal CT studies will show dilated bowel loops without evidence of mechanical obstruction. Manometry reveals widespread hypomotility. Intestinal pseudo-obstruction typically responds well to corticosteroids and other immunosuppressant therapies.26
Emergent Conditions
Acute Abdominal Pain. Approximately half of SLE patients who present to the ED with acute abdominal pain are found to have either mesenteric vasculitis or pancreatitis, both of which are thought to be related to SLE disease activity.27 Other causes of acute abdominal pain that are common in the general population remain common in SLE patients, including gallbladder disease, gastroenteritis, appendicitis, and peptic ulcer disease.
Mesenteric Vasculitis. Also known as lupus enteritis, mesenteric vasculitis is a unique cause of acute abdominal pain in SLE patients. The condition presents with acute, diffuse abdominal pain and may be associated with nausea and vomiting, diarrhea, or hematochezia. Abdominal CT findings suggestive of diffuse enteritis support the diagnosis. Medical management with pulse-dose corticosteroids and supportive care is generally sufficient, but if bowel necrosis or intestinal perforation is present or suspected, surgical consultation should be obtained immediately.15
Conclusion
Complications of SLE are diverse and may be difficult to diagnose. Understanding the common and emergent complications of SLE will help the EP to recognize severe illness and make appropriate treatment decisions in this complex patient population.