Management of Severe Infectious Colitis with Marked Leukocytosis and Acute Kidney Injury

Diagnostic Laboratory Workup

The presence of leukopenia with neutrophilia represents a paradoxical finding indicating severe infection with bone marrow exhaustion, which is a red flag for neutropenic enterocolitis or overwhelming bacterial sepsis, according to the American College of Emergency Physicians 5, 6, 7
Pyuria and microhematuria suggest concurrent urinary tract infection or systemic inflammatory response, as noted by the Infectious Diseases Society of America 8
Pus in feces confirms invasive bacterial enterocolitis requiring antibiotic therapy, as recommended by the American College of Gastroenterology 8, 9
Increased thirst indicates ongoing fluid losses and inadequate rehydration despite initial oral rehydration solution (ORS), highlighting the need for aggressive fluid resuscitation, as emphasized by the World Health Organization 8

Stool studies must include C. difficile toxin assay, bacterial cultures for Salmonella, Shigella, Campylobacter, E. coli (including O157:H7), and Yersinia, as recommended by the Centers for Disease Control and Prevention 8, 6, 10, 7, 9
Abdominal CT scan with IV contrast is mandatory to evaluate for neutropenic enterocolitis, bowel wall thickening (>10mm indicates 60% mortality risk), and complications such as perforation or abscess, as suggested by the American College of Radiology 5, 6, 11
Empirical antibiotic therapy should be started immediately with piperacillin-tazobactam, imipenem-cilastatin, or meropenem, which provide coverage for Pseudomonas, Staphylococcus aureus, E. coli, group A Streptococcus, and anaerobes, as recommended by the Infectious Diseases Society of America 5, 6, 7, 12

Bowel rest (NPO status) and nasogastric decompression may be necessary to reduce mechanical stress on the inflamed bowel and prevent complications, as noted by the American College of Surgeons 5, 6, 7, 12, 11
Electrolyte replacement, including potassium and sodium, should be guided by laboratory values, as recommended by the National Institute of Diabetes and Digestive and Kidney Diseases 8, 9
Surgical consultation is mandatory if there are signs of perforation, abscess, or clinical deterioration despite aggressive medical therapy, as emphasized by the American College of Surgeons 5, 6, 7, 12

IV antibiotics should be continued until the neutrophil count recovers or there is clinical improvement with resolution of fever and ability to tolerate oral intake, as recommended by the Infectious Diseases Society of America 5, 6, 13, 7
The typical duration of antibiotic therapy is 7-10 days, but may need to be adjusted based on culture results and susceptibility data, as noted by the Centers for Disease Control and Prevention 13, 14
Adjusting antibiotics based on culture results and susceptibility data is crucial to ensure effective treatment, as recommended by the Infectious Diseases Society of America 8, 13, 9