Trauma Registry Professionals Coming to Terms with Shock Index

By Michael Trelow, CSTR, CAISS

Sometimes, the need for a massive transfusion in trauma patients is immediately apparent when they arrive in the emergency department trauma room. However, occasionally, a seemingly stable trauma patient may suddenly experience a drop in blood pressure, surprising the trauma team.

In the trauma data world, trauma registry professionals must learn predictive tools that they can document accurately. Such predictive tools would include a Revised Trauma Score (RTS), Injury Severity Score (ISS), and Glasgow Coma Scale (GCS). We are going to look at another predictive tool, Shock Index (SI), and break it down into its predictions.

Blood pressure and heart rate, when used individually, fail to accurately predict the severity of hypovolemia and shock in major trauma. The Shock Index (SI) is a straightforward calculation derived by dividing the heart rate (HR) by the systolic blood pressure (SBP). Emergency Medical Services (EMS) can quickly determine this index, and it is valuable in assessing whether a patient needs transport to a trauma center.

Additionally, in the Emergency Department triage area, SI helps identify patients at risk of hemorrhagic shock (HS) and the potential need for massive transfusions. It has been researched in patients who are either at risk of or experiencing shock due to various causes, including trauma, hemorrhage, myocardial infarction, pulmonary embolism, sepsis, and ruptured ectopic pregnancy.

Shock Index Levels

When it is broken down, the SI is looking at different levels of shock:

• No Shock: <0.6
• Mild Shock: ≥0.6 to <1.0
• Moderate Shock: ≥1.0 to <1.4
• Severe Shock: ≥1.4

Trauma Registry professionals should be able to understand all the predictive tools and help them know the SI and not simply add it to the trauma registry should the trauma center be collecting the data but be able to understand that the higher the SI, looking for the use of the massive transfusion policy (MTP) and find the type and number of units of different blood products being used.  Linking their critical thinking to potential performance improvement issues will make the trauma registry professional stand out and aid in better care for the trauma patient.

To read more about the SI, in 2010, the paper was presented at the 23rd Annual Scientific Assembly of the Eastern Association for the Surgery of Trauma:

Identifying Risk for Massive Transfusion in the Relatively Normotensive Patient: Utility of the Prehospital Shock Index