What is the initial workup and management for a patient with a suspected splenic infarct?

Workup for Splenic Infarct

Initial Diagnostic Imaging

Contrast-enhanced CT scan is the gold standard for diagnosing splenic infarction, with 90-95% sensitivity and specificity, showing characteristic peripheral wedge-shaped low-density areas. 1, 2

• Perform CT abdomen with IV contrast as the primary diagnostic modality in hemodynamically stable patients 3, 1
• On CT, splenic infarcts appear as peripheral, wedge-shaped, low-density areas that do not enhance with contrast 1, 2
• MRI offers similar diagnostic accuracy to CT and can be used as an alternative imaging modality 1
• Doppler ultrasound should be added to evaluate splenic vascularization and detect vascular complications 1, 2
• Contrast-enhanced ultrasound (CEUS) is useful as an adjunct for follow-up monitoring 3
• Avoid nuclear medicine scans (99mTc liver-spleen scans, labeled WBC scans, gallium scans) as they are obsolete and provide no diagnostic value 1

Clinical Assessment

Assess hemodynamic stability immediately (systolic BP ≥90 mmHg without skin vasoconstriction, altered consciousness, or dyspnea) as this determines the entire management pathway. 3, 2

Key Clinical Features to Identify:

• Left upper quadrant pain is the predominant symptom, present in approximately 69% of patients 4, 5
• Fever and chills occur frequently, especially in embolic causes (70% of cases) 4
• Constitutional symptoms may be present 4
• Note that 31% of patients may be asymptomatic, particularly those with nonmalignant hematologic conditions (55% asymptomatic) 4
• Clinical splenomegaly is present in only 30% of cases and is not a reliable indicator 1, 2

Laboratory Workup

• Complete blood count: look for anemia (53% of cases), leukocytosis (49%), and thrombocytosis (7%) 5
• Serial hematocrit measurements to monitor for bleeding 1, 2
• Blood cultures if fever is present to rule out progression to abscess 1, 2

Etiologic Investigation

Evaluate for three main categories of underlying causes: hematologic disorders (most common in patients <40 years), thromboembolic disorders (most common in patients >41 years), and other conditions. 4, 5

Specific Conditions to Investigate:

• Hematologic disorders: chronic myeloid leukemia, other myeloproliferative disorders, sickle cell disease 4, 6, 5
• Thromboembolic sources: atrial fibrillation (including paroxysmal), infective endocarditis (causes 40% of left-sided endocarditis cases to have splenic infarction), acute myocardial infarction, dilated cardiomyopathy, prosthetic valves 1, 6, 7
• Other causes: collagen vascular diseases, pancreatic disorders, splenic vascular abnormalities, aortic atheromatous debris 3, 5, 7

Cardiac Workup for Embolic Sources:

• ECG to detect atrial fibrillation 6, 7
• Echocardiography (transthoracic or transesophageal) to identify cardiac thrombi, valvular vegetations, or structural abnormalities 7
• Blood cultures if endocarditis is suspected 1, 7

Monitoring for Complications

Watch vigilantly for signs suggesting progression to splenic abscess: persistent or recurrent fever, ongoing abdominal pain, recurrent bacteremia, and persistence or enlargement of splenic defects on serial imaging. 1, 2

Imaging Differentiation:

• Bland infarcts: peripheral wedge-shaped low-density areas that show clinical and radiographic improvement with appropriate therapy 1, 2
• Splenic abscess: single or multiple contrast-enhancing cystic lesions with ongoing sepsis and recurrent positive blood cultures 1, 2

When to Repeat CT:

• Consider repeat CT scanning in patients with moderate/severe lesions, decreasing hematocrit, vascular anomalies, underlying splenic pathology, coagulopathy, or neurologic impairment 2
• Repeat imaging before hospital discharge or when complications are suspected 3

Initial Management Protocol

Admit patients to an institution with 24/7 capacity for emergency interventions, provide continuous monitoring for at least 24 hours in an ICU, and implement bed rest for 48-72 hours. 3, 1, 2

• Clinical and laboratory observation for minimum 3-5 days 3
• Hydration and analgesics for symptom control 5
• Serial clinical examinations and laboratory monitoring with immediate access to surgery and blood products 1
• Monitor for abdominal compartment syndrome as a potential complication 3

Common Pitfalls to Avoid

• Do not rely on clinical splenomegaly as it is present in only 30% of cases 1, 2
• Do not miss concomitant infarcts in other organ systems, which occur in 62% of thromboembolic cases 7
• Do not delay imaging in patients with known hematologic or thromboembolic conditions who develop left upper quadrant pain 4, 5
• Remember that delayed splenic rupture can occur within the first 48 hours but more commonly between 4-10 days, requiring vigilant monitoring 2, 8