Pre-hospital Hypoxemia in Trauma Patients

Trauma patients in the United States frequently receive high-flow high-concentration
supplemental oxygen in the pre-hospital setting, yet their physiologic need is rarely known.
Providing oxygen to everyone regardless of need may seem straightforward, but the practice
has extensive implications in logistically challenging areas such as a combat arena or mass
casualty event, and is not supported by care guidelines. Indeed, too much oxygen can be
harmful for some patients.1, 2 If it is the case, that not all trauma patients require
oxygen, this would decrease the logistical burden of providing oxygen in the pre-hospital
environment. No study has yet been performed that describes the proportion of patients
requiring oxygen, the amount of oxygen they require, and whether or not oxygen is beneficial
to outcomes. This prospective observational cohort investigation aims to bridge the
knowledge gap surrounding the need and possible benefits or harms arising from oxygen
therapy. In our Emergency Medical Services (EMS) systems, the written standard of care is to
provide oxygen only to maintain oxygen saturation at 95% or when hemorrhagic shock or
traumatic brain injury are suspected.3 We will observe patterns of oxygen treatment and
outcome for patients treated according to this written standard of care, and compare this to
the treatment and outcomes for patients transported by EMS units who continue their usual
practice pattern.

Specifically, we aim to:

1. Identify the proportion of trauma patients who are hypoxemic or who have traumatic
brain injury or hemorrhagic shock at the time of initial EMS contact

2. Identify the proportion of trauma patients who develop hypoxemia or hemorrhagic shock
while in the pre-hospital setting

3. Identify differences in clinically important outcomes associated with treatments driven
by written standard of care compared with the usual practice pattern of EMS units.
These outcomes include requirement for advanced airway management, hospital and
intensive care unit lengths of stay, and disposition (including in-hospital and 30-day
mortality)

4. Determine the amount of oxygen (Liters per minute) required to reverse hypoxemia

Inclusion Criteria:

- acute traumatic injury

- transported directly to study hospital

- meets at least one trauma consult/trauma stat criteria

Exclusion Criteria:

- lack of continuous peripheral pulse oximetry data

- age <18 years

- on prescribed home oxygen therapy prior to trauma