What is the appropriate diagnostic and management approach for a patient presenting with intermittent left upper quadrant abdominal pain, nausea, and lung pressure when lying down, with slight discomfort in the left lower quadrant on examination?

Diagnostic and Management Approach for Intermittent Left Upper Quadrant Pain with Positional Symptoms

This patient requires CT abdomen and pelvis with IV contrast as the initial diagnostic test to evaluate for splenic pathology, gastric disease, pancreatic abnormalities, diaphragmatic hernia, or atypical presentations of colonic pathology, given the combination of left upper quadrant pain with positional respiratory symptoms and discordant left lower quadrant tenderness on examination. 1

Initial Diagnostic Strategy

Obtain CT abdomen and pelvis with IV contrast immediately rather than relying on clinical assessment alone, as this presentation has multiple concerning features that require imaging clarification. 1 The American College of Radiology rates CT with IV contrast as 8/9 (usually appropriate) for evaluating left upper quadrant pain, providing comprehensive assessment with excellent diagnostic accuracy. 1

Key Clinical Features Requiring Imaging

• Positional component with lung pressure sensation: This suggests possible diaphragmatic pathology, hiatal hernia, or splenic flexure syndrome that requires anatomic visualization. 1
• Discordant examination findings: Pain reported in left upper quadrant but tenderness elicited in left lower quadrant indicates either referred pain or multiple pathologic processes. 2
• Intermittent nature with postural aggravation: While functional disorders can present this way, structural causes (splenic pathology, gastric volvulus, diaphragmatic hernia) must be excluded first. 1

Why CT is Essential in This Case

CT abdomen and pelvis with IV contrast provides several critical advantages:

• Detects splenic pathology including infarction, abscess, or subcapsular hematoma that may present with referred shoulder pain or respiratory symptoms. 1
• Identifies gastric abnormalities such as gastric outlet obstruction or volvulus that worsen when supine. 1
• Visualizes diaphragmatic hernias that cause both abdominal pain and respiratory symptoms when lying down. 1
• Reveals unexpected findings including malrotation with atypical appendicitis or colonic pathology presenting in unusual locations. 1
• Alters diagnosis in 49% of cases with nonlocalized abdominal pain according to prospective data. 1

Alternative Diagnoses to Consider

If Imaging is Negative or Equivocal

Splenic flexure syndrome: Trapped gas in the splenic flexure can cause left upper quadrant pain radiating to the chest, worsened by lying down. However, this is a diagnosis of exclusion after imaging rules out structural pathology. 1

Functional dyspepsia with gastroesophageal reflux: The positional component and nausea suggest possible GERD, but the lack of meal association and presence of left lower quadrant tenderness make this less likely as the sole diagnosis. 1

Musculoskeletal pain: Costochondritis or intercostal muscle strain can cause positional chest/upper abdominal pain, but would not explain left lower quadrant tenderness. 2

Critical Pitfalls to Avoid

• Do not dismiss as benign without imaging when clinical suspicion exists, as the American College of Radiology emphasizes that CT findings frequently alter management. 1
• Do not order plain radiography as it has very limited diagnostic value for left upper quadrant pain and will not visualize the pathology needed to guide management. 1
• Do not rely on ultrasound in this location due to overlying bowel gas and rib shadowing, though it may identify splenic or renal pathology if CT is contraindicated. 2
• Do not assume diverticulitis based on left lower quadrant tenderness alone, as clinical diagnosis has 34-68% misdiagnosis rates without imaging. 3

Management Algorithm Based on CT Findings

If CT Shows Uncomplicated Diverticulitis (WSES Stage 0)

• Conservative management without antibiotics for immunocompetent patients. 3
• Clear liquid diet advancement with oral analgesics for pain control. 3
• Outpatient follow-up in 2-3 days to ensure clinical improvement. 3

If CT Shows Complicated Diverticulitis with Small Abscess (<4 cm)

• Antibiotic therapy alone for 7 days without drainage. 3
• Use Ertapenem 1 g q24h or Eravacycline 1 mg/kg q12h as standard regimens. 3
• Admission for IV antibiotics if unable to tolerate oral intake. 3

If CT Shows Complicated Diverticulitis with Large Abscess (≥4 cm)

• Percutaneous drainage plus antibiotics for 4 days in immunocompetent, non-critically ill patients. 3
• Interventional radiology consultation for CT-guided drainage. 3
• Stop antibiotics at 4 days if source control is adequate. 3

If CT Shows Alternative Pathology

• Splenic pathology: Surgical consultation for infarction, abscess, or traumatic injury. 1
• Gastric pathology: Gastroenterology referral for endoscopy if mass or outlet obstruction identified. 1
• Diaphragmatic hernia: Surgical evaluation for repair if symptomatic. 1

Red Flags Requiring Emergency Surgery

Immediate surgical consultation is required for:

• Signs of peritonitis (diffuse tenderness, guarding, rebound tenderness, absent bowel sounds). 4
• Free air on CT indicating perforation. 4
• Hemodynamic instability (hypotension, tachycardia, altered mental status). 4
• Clinical deterioration despite medical management. 4

Special Considerations

If IV contrast is contraindicated (severe renal disease or contrast allergy), CT without contrast is acceptable but less accurate for detecting abscesses, rated 6/9 by the American College of Radiology. 2

For women of reproductive age, obtain pregnancy testing before CT and consider gynecologic causes if clinically appropriate, though the left upper quadrant location makes this less likely. 2

MRI may be considered if CT is contraindicated and available, with sensitivity of 86-94% and specificity of 88-92% for diverticulitis, though less studied for left upper quadrant pathology. 2