Shock Index, Pediatric Age-Adjusted (SIPA)

Shock Index Pediatric Age-Adjusted (SIPA)

Heart Rate

bpm

Systolic Blood Pressure

mmHg

Age Group

Score:–

–

Predicts mortality in children with blunt trauma.

Why Use

Better differentiates severely injured children from those with mild injury than the Shock Index (SI) . In the original study, an elevated SIPA was shown to identify approximately 25% of the most severely injured children, regardless of age, while SI >0.9 has been shown to identify anywhere from 32-71% of injured children, depending on age. Being able to accurately identify severely injured children is critical in reducing the over-triage of children that have sustained injuries. Elevated SIPA is associated with the following outcomes ( Acker 2015 ; Nordin 2017 ): Higher injury severity. Need for blood transfusion in the first 24 hours. Longer ICU and hospital length of stay. Higher number of ventilator days. Discharge to a rehabilitation facility. Increased risk of mortality.

When to Use

Patients 4-16 years old who have sustained blunt trauma. Do not use in young infants, toddlers, or patients with penetrating trauma.

Formula

SIPA = maximum heart rate/minimum systolic blood pressure, where normal values are as follows: Age Heart rate Systolic blood pressure Maximum normal SIPA 4–6 years 65–110 90–110 1.22 7–12 years 60–100 100–120 1.00 13-16 years 55–90 100–135 0.90

Pearls / Pitfalls

SIPA should be calculated on presentation to the emergency department. Uptrending SIPA between the field and ED may predict poor outcomes but was not examined by the original authors. The use of SIPA to predict morbidity and mortality following admission has not yet been validated. However, a prognostic study in the Journal of Pediatric Surgery ( Vandewalle 2018 ) found that patients who developed an elevated SIPA within the first 24 hours of admission were at increased risk of complications compared to those whose SIPA remained normal throughout the first 48 hours of admission. In addition, time to normalize SIPA directly correlated with length of hospital and ICU stay. Per the authors, the age-specific cutoffs originally chosen will require further validation in a second cohort.

Management

General management of pediatric blunt abdominal trauma includes primary and secondary survey and determination of extent, type, and severity of injury. A thorough abdominal exam is extremely important as abdominal injuries are often not apparent on exam. The use of imaging may be warranted depending on exam findings.

Critical Actions

Remember that there is no value or finding that necessarily defines shock, and children can compensate more readily than adults. Hypotension is often a late finding in children with hypovolemic shock.

Advice

Patients that present with an elevated SIPA are at higher risk of morbidity and mortality following blunt trauma. Early recognition and treatment in these cases, including a possible decision to transfer to a higher level of care, will improve outcomes in these children.

More Information

Interpretation: Age SIPA Risk of blunt injury if SIPA is elevated 4–6 years >1.22 22.0% 7–12 years >1.00 25.1% 13-16 years >0.90 32.0% Overall in-hospital mortality for elevated SIPA (at each cutoff) was 11%, versus 7% for non-age-adjusted shock index.