What are the components of a comprehensive abdominal physical assessment?

Abdominal Physical Assessment Components

A comprehensive abdominal physical assessment consists of four systematic components performed in sequence: inspection, auscultation, percussion, and palpation, supplemented by targeted laboratory and imaging studies when clinically indicated. 1

Inspection

• Observe the abdomen for distension, visible peristalsis, pulsations, skin changes, surgical scars, and asymmetry while the patient is supine and relaxed 1, 2
• Document any abdominal masses, noting their location, size, consistency, mobility, and whether they are pulsatile (which may indicate vascular pathology like abdominal aortic aneurysm) 2
• Look for signs of weight loss, cachexia, or dilated superficial veins that may suggest underlying pathology 2
• Remove the patient's shoes and socks to inspect feet for color, temperature, skin integrity, ulcerations, distal hair loss, trophic skin changes, and hypertrophic nails 3, 1

Auscultation

Auscultation must be performed before percussion and palpation to avoid artificially stimulating bowel sounds. 4

• Listen for bowel sounds in all four quadrants, noting their character, frequency, and pitch 1
• Auscultate the abdomen and flanks for bruits, which may indicate renal artery stenosis, mesenteric ischemia, or abdominal aortic aneurysm 3, 1
• Auscultate both femoral arteries for the presence of bruits 3

Percussion

• Percuss all four quadrants systematically to detect abnormal fluid accumulation, masses, or organomegaly 1
• Assess for shifting dullness and fluid thrill when ascites is suspected, which helps differentiate free fluid from other causes of abdominal distension 1
• Percussion can help identify the span of the liver and spleen 4

Palpation

• Begin with light palpation in areas away from reported pain, then progress to deeper palpation to assess for masses, organomegaly, and tenderness 1
• Palpate the abdomen for aortic pulsation and measure its maximal diameter, as this is critical for detecting abdominal aortic aneurysms 3, 1
• Palpate all peripheral pulses (brachial, radial, ulnar, femoral, popliteal, dorsalis pedis, and posterior tibial) and grade pulse intensity numerically: 0=absent, 1=diminished, 2=normal, 3=bounding 3, 5
• Palpate and inspect lower extremities for edema and presence of arterial pulses 3
• Assess for rebound tenderness, guarding, and rigidity, which indicate peritoneal irritation 2

Digital Rectal Examination

• Perform digital rectal examination when indicated, especially for suspected lower gastrointestinal pathology, constipation evaluation, or when assessing for occult blood 1, 2
• Evaluate for rectocele or consider gynecologic consultation when appropriate 1
• Test the anal reflex and observe perianal skin for evidence of fecal soiling 1

Vital Signs and General Assessment

• Record pulse rate and regularity, blood pressure (in both arms when vascular disease is suspected), temperature, respiratory rate, weight, and height 3, 1, 5
• Calculate body mass index from height and weight measurements 5
• Assess for signs of hemodynamic compromise including tachycardia, fever, and hypotension, which may indicate perforation or sepsis 2

Mandatory Laboratory Assessment

When acute abdominal pathology is suspected, obtain the following laboratory studies: 1

• Complete blood count to assess for anemia, thrombocytosis, or leukocytosis 1
• Electrolytes, liver enzymes, and renal function 1
• Inflammatory markers (ESR, CRP), which broadly correlate with clinical severity in inflammatory conditions 3, 1
• Albumin and iron studies 3
• Stool analysis for occult blood, ova and parasites, and C. difficile toxin when diarrhea is present 3

Imaging Studies When Indicated

• CT scan with IV contrast is the recommended primary imaging study for suspected acute abdominal pathology, with superior sensitivity (93-96%) and specificity (93-100%) for detecting complications such as perforation, abscess, obstruction, or bleeding 3, 1
• Abdominal ultrasound can be used as a screening test with moderate sensitivity (88%) when CT is unavailable or contraindicated 3, 1
• Plain abdominal radiography should be obtained during acute presentations to identify bowel obstruction, perforation, or masses 3, 2

Critical Pitfalls to Avoid

• Do not delay surgical consultation if there is high clinical suspicion and alarming signs (fever, weight loss, blood in stools, peritoneal signs), even with negative initial radiological assessment 1
• Do not skip auscultation or perform it after palpation, as this can artificially alter bowel sounds 4
• Do not assume all pulsatile masses are aortic aneurysms, as normal aortic pulsation can be prominent in thin patients 2
• Early involvement of a surgeon is required in cases of suspected perforation or peritonitis 1