From the Guidelines
To examine for neurovascular compromise above and below a joint in a bone fracture, a systematic assessment of circulation, sensation, and motor function in the affected limb is crucial, and the Ankle-Brachial Index (ABI) should be measured if possible, as an ABI <0.9 has been shown to have a satisfactory sensitivity and specificity for diagnosing vascular injury 1. When assessing circulation, compare the injured limb to the uninjured side, checking for differences in skin color, temperature, and capillary refill. Palpate pulses distal to the injury, such as the radial and ulnar pulses for upper extremity fractures or dorsalis pedis and posterior tibial pulses for lower extremity fractures. The ABI measurement is performed with the patient in a supine position, using a Doppler probe positioned at an angle of 45° to detect arterial flow, and the ratio between the systolic blood pressure measured at the ankle and the arm is calculated 1. Some key points to consider when examining for neurovascular compromise include:
- Assessing sensation by testing light touch in all nerve distributions distal to the injury
- Evaluating motor function by having the patient perform gentle movements of the digits and joints distal to the fracture
- Documenting findings clearly and reassessing frequently, especially after any manipulation or immobilization of the fracture
- Notifying the treating physician immediately if any signs of compromise are detected, such as absent pulses, delayed capillary refill, numbness, tingling, weakness, or severe pain with passive movement. According to a recent meta-analysis, in the absence of clinical signs suggesting a vascular injury and in the presence of a normal ABI, the probability of vascular injury is virtually zero, with a negative likelihood ratio of 0.01 1.
From the Research
Examining for Neurovascular Compromise
To examine for neurovascular compromise above and below a joint in a bone fracture, the following steps can be taken:
- Assess the patient's neurovascular status by evaluating pain, warmth, color, movement, sensation, and pulses 2, 3, 4
- Monitor for signs of compartment syndrome, such as pain out of proportion to the injury, numbness, tingling, and coolness to the distal extremity 5, 6
- Check for decreased pulse oximetry and poor capillary refill, which can indicate compromised circulation 5
- Evaluate the patient's motor function and sensory nerves for any impairment 5, 3
- Continually assess the patient's neurovascular parameters to determine any deviation from the normal range 2
Prevention and Treatment
Prehospital treatment of extremity injuries can help prevent or limit compartment syndrome by:
- Immobilization, elevation, and cooling of the affected limb 5
- Avoiding constricting dressings or casts 6
- Optimizing tissue perfusion by keeping the limb at heart level 6
- Recognizing the need for medical evaluation of seemingly minor injuries 5
- Educating patients to seek care if symptoms of numbness, deep pain, and coolness to the distal extremity occur 5
Importance of Early Identification
Early identification of neurovascular compromise and compartment syndrome is critical to prevent long-term morbidity and mortality 2, 3, 6, 4