What is the PECARN rule used to evaluate the baby in the Pitt Season 2?

In the 7 a.m. season 2 premiere of The Pitt, the emergency department (ED) at Pittsburgh Trauma Medical Center begins the day with a case that quickly becomes one of the episode’s main points: a very young baby found alone in the hospital. The baby’s age and unclear condition place the care team under pressure to make hard decisions. This mirrors the real-world challenges faced daily in pediatric EDs.

As the episode unfolds, the doctors, led by Samira Mohan, MD, and Michael Robinavitch, MD, take the responsibility of caring for the baby. They then started a rapid evaluation to determine the cause of the infant’s symptoms and whether the baby is at risk for a serious infection. The storyline highlights a situation that happens often when caring for very young infants. Something particularly true when fever or other subtle signs of illness can signal a dangerous condition. In this moment, The Pitt introduces viewers to a real clinical decision tool used in pediatric emergency medicine: the PECARN febrile infant rule.

The baby’s evaluation reflects the type of decision-making clinicians use when assessing infants younger than three months with fever. The care team reviews laboratory results, considers infection risk and weighs whether invasive procedures — such as a lumbar puncture — are necessary. This approach aligns with how clinicians apply the PECARN febrile infant rule in practice. They use specific test results to determine which infants are at low risk for serious bacterial infection and which need more aggressive evaluation and treatment.

By grounding the baby’s storyline in this type of medical reasoning, the show connects fictional drama with real clinical tools that guide pediatric care.

What is the PECARN Febrile Infant Rule?

The PECARN febrile infant rule is a clinical prediction tool designed to help clinicians safely evaluate young infants with fever, particularly those younger than 60 days who present to the ED and other outpatient settings. Fever in this age group has traditionally prompted extensive testing and hospital admission because infants can have serious bacterial infections without obvious symptoms.

The PECARN rule identifies infants who are at low risk for invasive bacterial infections, including bacteremia and bacterial meningitis, using three routinely available laboratory criteria:

• A negative urinalysis
• An absolute neutrophil count (ANC) of 4,000 cells per mm³ or less
• A serum procalcitonin level of 0.5 ng/mL or less

When all three criteria are met, an infant is classified as low risk. Large, multi-center studies have shown that infants meeting these criteria have an extremely low likelihood of having an invasive bacterial infection. This evidence allows clinicians to make more individualized decisions and, in some cases, avoid unnecessary invasive procedures while maintaining patient safety.

How the PECARN Rule Came to be

The PECARN febrile infant rule was developed through the Pediatric Emergency Care Applied Research Network (PECARN) — the largest pediatric emergency medicine research network in the United States. PECARN brings together investigators from children’s hospitals nationwide to answer critical questions about emergency care for children using rigorous, collaborative science.

One of the key leaders in this work is Nathan Kuppermann, MD, MPH, pediatric emergency medicine physician and chief academic officer at Children’s National Hospital. Dr. Kuppermann and his colleagues recognized the need for a more precise, evidence-based approach to evaluating young febrile infants — one that could accurately identify low-risk patients without compromising safety.

Through large, prospective studies involving thousands of infants across multiple institutions, the PECARN team developed and validated the rule, demonstrating its ability to safely reduce unnecessary testing while maintaining a near-zero risk of missed serious bacterial infections. This work reflects the power of team science and national collaboration to improve care for children.

From Screen to Clinical Practice

By weaving a realistic infant evaluation into its season 2 premiere, The Pitt brings attention to the complexity of caring for the youngest patients, and to the research-driven tools clinicians rely on when the stakes are highest. This mention is already driving interest in the rule, as shown by Google Trends, showing the importance of these types of connections. The PECARN febrile infant rule, developed through years of collaboration and led by Dr. Kuppermann and other PECARN investigators, including those at Children’s National, continues to shape how EDs nationwide deliver safer, more precise care for infants, older children and their families.