Surgical Abdomen in Children: Causes, Diagnosis, and Treatment
Most Common Causes
Acute appendicitis is the most common abdominal surgical emergency in children, accounting for the majority of cases requiring urgent intervention 1, 2. The leading causes of surgical abdomen in pediatric patients include:
- Acute appendicitis (most common in developed settings) 1
- Intestinal obstruction including intussusception, malrotation with volvulus, and adhesions 3, 4
- Incarcerated/strangulated hernias 5, 4
- Meckel's diverticulum with complications (bleeding, perforation, obstruction) 4
- Abdominal trauma with solid organ injury or hollow viscus perforation 5
- Necrotizing enterocolitis (primarily in premature and full-term stressed neonates) 1
- Typhoid perforation (in endemic regions, can account for up to 68% of cases) 5
- Primary peritonitis 5
Diagnostic Approach
Clinical Assessment
Begin with focused evaluation for characteristic findings: abdominal pain pattern (especially migration to right lower quadrant), localized tenderness, fever, and laboratory evidence of acute inflammation 1, 2. Key clinical features include:
- Pain migration to right lower quadrant (LR+ = 4.81) strongly suggests appendicitis 6
- Cough/hop pain or percussion tenderness (LR+ = 7.64) is highly predictive 6
- Rovsing's sign (LR+ = 3.52) in patients with suspected appendicitis 6
- Psoas sign and fever increase likelihood of appendicitis 7
- Vomiting before pain onset makes appendicitis less likely 7
No single clinical finding or scoring system can definitively rule in or rule out appendicitis—imaging is required for most patients 1, 2, 6.
Imaging Strategy (Age and Gender-Specific)
For Non-Pregnant Children and Adolescents:
Ultrasound is the recommended initial imaging modality to avoid radiation exposure, with sensitivity of 76% and specificity of 95% 1, 7. However:
- Point-of-care ultrasound by emergency physicians or surgeons achieves higher accuracy (sensitivity 91%, specificity 97%) 7
- If ultrasound is non-diagnostic or negative but clinical suspicion remains high, proceed to CT with IV contrast 1
- CT abdomen/pelvis with IV contrast achieves sensitivity of 96-100% and specificity of 93-95% 1, 7
- Children aged <3 years should always undergo imaging when diagnosis is uncertain 1, 2
For Female Patients of Childbearing Age:
All female patients should undergo diagnostic imaging, with pregnancy testing prior to any radiation-based study 1, 2. If pregnant:
- First trimester: ultrasound is initial modality; if inconclusive, proceed to MRI without IV contrast (sensitivity 94%, specificity 96%) 1, 7
- Avoid CT in first trimester unless ultrasound and MRI are unavailable or non-diagnostic 1
For Adult-Sized Adolescents and Young Adults:
CT abdomen/pelvis with IV contrast only (no oral or rectal contrast) is the preferred imaging modality 1, 7. Key technical points:
- IV contrast increases sensitivity to 96% compared to unenhanced CT 7
- Oral contrast is unnecessary and delays diagnosis 1, 7
- CT reduces negative appendectomy rates from historical 14.7% to current 1.7-7.7% 7
CT Findings Suggesting Complicated Disease:
Look for extraluminal appendicolith, abscess formation, extraluminal air, appendiceal wall enhancement defects, and extensive periappendiceal fat stranding 7. These findings indicate need for urgent surgical consultation and possible source control procedures.
Management After Imaging:
If imaging is negative but clinical suspicion persists, 24-hour follow-up is mandatory due to measurable false-negative rates 1. Options include:
- Hospital observation if index of suspicion remains high 1, 2
- Discharge with strict return precautions and scheduled reassessment 1, 7
Treatment
Antibiotic Therapy
Administer broad-spectrum antibiotics immediately once appendicitis is diagnosed or strongly suspected, covering aerobic gram-negative organisms and anaerobes 1, 7.
For Perforated Appendicitis with Peritonitis:
Appropriate regimens include carbapenems (imipenem or meropenem), piperacillin-tazobactam, ticarcillin-clavulanate, or extended-spectrum cephalosporin (cefotaxime, ceftriaxone, ceftazidime, or cefepime) with metronidazole 1.
The traditional triple therapy of gentamicin, ampicillin, and clindamycin (or metronidazole) remains effective in children 1.
Duration and Step-Down Therapy:
Continue IV antibiotics until fever resolves, pain is controlled, patient tolerates oral fluids, and can ambulate 1. For oral step-down:
- Second- or third-generation cephalosporin with metronidazole, or amoxicillin-clavulanate if organisms are susceptible 1
- Fluoroquinolones (ciprofloxacin or levofloxacin) with metronidazole for resistant gram-negatives in older children 1
- Base selection on intraoperative culture results when available 1
Surgical Management
Appendectomy should be performed as soon as reasonably feasible once diagnosis is established 7. Surgical approach:
- Both laparoscopic and open appendectomy are acceptable 7
- Laparoscopic approach is preferred in children when expertise is available 7
- Large periappendiceal abscess or phlegmon may warrant percutaneous drainage rather than immediate appendectomy 7
Special Surgical Conditions
Necrotizing Enterocolitis (Neonates):
In very low birth weight neonates with perforation, peritoneal drainage may be used instead of immediate operation 1. Management options:
- Some surgeons use drainage as definitive treatment with antibiotics 1
- Others use drainage as temporizing measure before formal operation 1
- Formal operation involves bowel resection with stomas or reanastomosis 1
- Survival rate is 95% for localized disease but drops to 10-60% when entire bowel is involved 1
Malrotation with Volvulus:
This is a true surgical emergency requiring immediate operation to prevent bowel necrosis and death 4. Any delay significantly worsens prognosis.
Intussusception:
Attempt pneumatic or hydrostatic reduction first in stable patients without peritonitis 4. Surgical reduction is required if:
Clinical Pearls and Pitfalls
Critical Pitfalls to Avoid:
Never withhold pain medication while awaiting diagnosis—this outdated practice impairs examination without improving diagnostic accuracy 8. Provide:
Do not proceed directly to surgery without imaging in patients with incomplete or atypical presentations—this risks unnecessary surgery and missing alternative diagnoses 7. The exception is young males under 40 with classic presentation where immediate surgery may be appropriate 2.
Ultrasound accuracy is highly operator-dependent, and both ultrasound and MRI may incorrectly classify up to half of perforated appendicitis cases as simple appendicitis 7. Maintain high clinical suspicion despite reassuring imaging.
Low Alvarado scores do not reliably exclude appendicitis—studies show 8.4% of appendicitis patients had scores below 5, and one study found 72% with very low scores (1-4) ultimately had appendicitis 7.
System-Level Recommendations:
Hospitals should establish standardized clinical pathways involving surgeons, emergency physicians, radiologists, infectious disease specialists, and pharmacists to ensure comprehensive management from presentation through discharge 1, 2. These pathways:
- Reduce unwarranted clinical variation 1
- Prevent avoidable morbidity 1
- Decrease length of stay and antibiotic usage 1
- Ensure reliable documentation of follow-up 1
High-Risk Populations Requiring Expedited Care:
Pregnant women and immunocompromised patients should undergo timely surgical intervention to decrease complications 2. Delays in these populations significantly increase morbidity and mortality.
Elderly children (adolescents) have higher rates of complicated appendicitis and require aggressive diagnostic workup with CT imaging 7.
When Persistent Symptoms Occur Post-Operatively:
Patients with persistent peritoneal irritation, failure of bowel function to return, or continued fever/leukocytosis require investigation for ongoing intra-abdominal infection 1. Obtain: