II. Indications
- Extremity Gunshot Wound evaluation (in which bullet trajectory is in vicinity of a major blood vessel)
III. Definition
- Arterial Pressure Index (API)
- Compares systolic pressure in injured extremity with uninjured extremity
- Contrast with Ankle Brachial Index (ABI)
- ABI is indicated in Peripheral Vascular Disease evaluation to compare systolic Blood Pressure between ankle and Forearm
IV. Technique
- Measure systolic Blood Pressure readings
- Injured extremity systolic Blood Pressure
- Contralateral uninjured extremity systolic Blood Pressure
- Arm is injured extremity: Obtain bilateral standard brachial systolic pressure
- Leg is injured extremity: Ankle systolic pressure in both legs
- Cuff applied to calf
- Record first doppler sound as cuff is deflated
- Use Doppler Ultrasound device
- Record dorsalis pedis pressure
- Record posterior tibial pressure
V. Calculation
- Arterial Pressure Index = (SBP injured) / (SBP uninjured)
VI. Interpretation
- Arterial Pressure Index > 0.9 suggests no arterial injury