Calculators & Tools

Palchak (UC Davis) Rule

Predicts traumatic brain injury on CT in children with blunt head trauma.

1 What is the Palchak (UC Davis) Rule?

The Palchak (UC Davis) Rule is a Neurology & trauma scoring tool used in paediatric practice. Predicts traumatic brain injury on CT in children with blunt head trauma. It scores 5 criteria and interprets the total across 2 bands, so the number always arrives with the severity it implies rather than on its own. In PediAid each criterion is shown as a labelled option with the weight it carries, so the total can be checked rather than taken on trust.

2 When to use it

  • Grading severity at the bedside in Neurology & trauma
  • Recording an objective severity band in the case notes
  • Deciding when a total crosses the threshold for escalation
  • Re-scoring to track whether a child is improving or deteriorating
  • Checking the exact criteria of a score used infrequently

3 Formula & method

The score sums 5 criteria: Abnormal mental status; Clinical signs of skull fracture; History of vomiting; Scalp haematoma (in children ≤ 2 years); Headache. Totals are then banded: any score - Very low risk: none of the five predictors - negative predictive value ≈100% for traumatic brain injury on CT. Imaging can reasonably be withheld; 1 predictor or more - Not low risk: one or more predictors present - the rule does not exclude TBI; consider CT or observation per clinical judgement and local guidance.
  • Source: Palchak MJ et al. A decision rule for identifying children at low risk for brain injuries after blunt head trauma. Ann Emerg Med 2003;42:492-506.

4 Frequently asked questions

How many criteria does the Palchak (UC Davis) Rule use?

5. They are Abnormal mental status; Clinical signs of skull fracture; History of vomiting; Scalp haematoma (in children ≤ 2 years); Headache.

What do the bands of the Palchak (UC Davis) Rule mean?

The total is interpreted as: any score - Very low risk: none of the five predictors - negative predictive value ≈100% for traumatic brain injury on CT. Imaging can reasonably be withheld; 1 predictor or more - Not low risk: one or more predictors present - the rule does not exclude TBI; consider CT or observation per clinical judgement and local guidance.

Does the score replace clinical judgement?

No. It is a structured way to record and communicate severity. A clinician concerned about a child should act on that concern regardless of the total.

Where does this score come from?

Source: Palchak MJ et al. A decision rule for identifying children at low risk for brain injuries after blunt head trauma. Ann Emerg Med 2003;42:492-506.

Does it work offline?

Yes. Score definitions are bundled with the PediAid app, so the score computes without a connection.

For qualified clinicians. This page and the PediAid app are a clinical aid only. Calculations and reference data must be verified against the patient's clinical context, the source guideline and your local protocols before any treatment decision is made.