What labs are recommended for the initial evaluation of necrotizing enterocolitis (NEC)?

From the Guidelines

For the initial evaluation of necrotizing enterocolitis (NEC), complete blood count (CBC), blood cultures, comprehensive metabolic panel, arterial blood gases, C-reactive protein, procalcitonin, coagulation studies (PT, PTT), and stool samples for occult blood and bacterial pathogens are essential laboratory tests. These tests help establish the diagnosis, assess disease severity, guide management decisions, and monitor for complications. According to the most recent and highest quality study 1, a high index of suspicion in patients undergoing conservative treatment with positive radiologic signs is mandatory. The study also suggests that immediate broad-spectrum antibiotic therapy must be initiated once the diagnosis is confirmed.

The following laboratory tests are recommended:

• Complete blood count (CBC) to assess for leukocytosis, leukopenia, or thrombocytopenia
• Blood cultures to identify any bacteremia
• Comprehensive metabolic panel to evaluate electrolyte imbalances and liver function
• Arterial blood gases to reveal metabolic acidosis
• C-reactive protein and procalcitonin as useful inflammatory markers
• Coagulation studies (PT, PTT) to check for coagulopathy
• Stool samples for occult blood and bacterial pathogens

It is crucial to note that early detection through these laboratory evaluations is vital as NEC can progress rapidly, particularly in premature infants, leading to intestinal perforation, sepsis, and significant mortality if not promptly identified and treated 1. Abdominal radiographs remain the cornerstone imaging study, looking for pneumatosis intestinalis, portal venous gas, or pneumoperitoneum.

In patients with suspected NEC, it is also important to consider the patient's clinical presentation, including fever, abdominal pain, nausea, vomiting, and diarrhea, as well as their medical history, including recent chemotherapy or immunocompromised status 1. The decision to perform laboratory tests should be guided by the physical examination and clinical presentation.

Overall, the initial evaluation of NEC requires a comprehensive approach, including laboratory tests, imaging studies, and clinical evaluation, to establish the diagnosis, assess disease severity, and guide management decisions.

From the Research

Initial Evaluation of Necrotizing Enterocolitis (NEC)

The initial evaluation of NEC involves various laboratory tests to diagnose and assess the severity of the disease.

• The following labs are recommended for the initial evaluation of NEC:
  • C-reactive protein (CRP) 2
  • Intestinal fatty acid binding protein (I-FABP) 2
  • Platelet-activating factor (PAF) 2
  • Leukocyte and platelet counts 3
  • Hemoglobin 3
  • Lactate 3
• A simple presurgical NEC-mortality scoring system can be used to assess the relationship between early laboratory parameters, disease severity, and outcome in NEC 3.
• Newer definitions of NEC, such as the Non-Bell definitions, may be more effective in identifying NEC compared to traditional definitions like Bell's staging 4.

Laboratory Parameters

Laboratory parameters play a crucial role in the diagnosis and management of NEC.

• CRP is a sensitive but nonspecific marker for NEC 2.
• I-FABP and PAF are both sensitive and specific markers for NEC 2.
• Leukocyte and platelet counts, hemoglobin, and lactate levels can be used to assess disease severity and predict outcomes in NEC 3.