OCC OCC Neurovascular Assessment & Monitoring 2 — Questions and Answers
Question 1: A patient with a recently applied long leg cast reports numbness of the little toe and the lateral aspect of the foot. Which nerve is most likely compressed?
- Deep peroneal nerve
- Superficial peroneal nerve
- Sural nerve (Correct answer)
- Tibial nerve
Correct answer: Sural nerve
The sural nerve provides sensation to the lateral foot and little toe, and is vulnerable to compression along the lateral ankle area.
Question 2: How frequently should neurovascular checks be performed during the first 24 hours after application of a new cast?
- Every 30 minutes
- Every 1–2 hours (Correct answer)
- Every 4–6 hours
- Once per nursing shift
Correct answer: Every 1–2 hours
Neurovascular checks every 1–2 hours during the first 24 hours are the standard of care to detect early signs of vascular compromise or compartment syndrome.
Question 3: The posterior tibial pulse in a patient with a short leg cast is best assessed by palpating:
- On the dorsum of the foot between the first and second metatarsals
- Behind the medial malleolus (Correct answer)
- Over the lateral malleolus
- At the popliteal fossa
Correct answer: Behind the medial malleolus
The posterior tibial artery passes posterior to the medial malleolus and is palpated there to assess distal perfusion of the foot.
Question 4: Testing motor function of the ulnar nerve is best accomplished by asking the patient to:
- Extend the wrist against resistance
- Oppose the thumb to the index finger
- Abduct the fingers (spread them apart) (Correct answer)
- Flex the elbow against resistance
Correct answer: Abduct the fingers (spread them apart)
Finger abduction is performed by the dorsal interossei, which are innervated by the ulnar nerve, making this the primary motor test for ulnar integrity.
Question 5: A patient with a short arm cast reports numbness and tingling in the little finger and the medial half of the ring finger. Which nerve is most likely compromised?
- Radial nerve
- Median nerve
- Ulnar nerve (Correct answer)
- Anterior interosseous nerve
Correct answer: Ulnar nerve
The ulnar nerve provides sensory innervation to the little finger and the medial half of the ring finger on both palmar and dorsal surfaces.
Question 6: Cyanosis of the toes in a patient with a lower extremity cast most likely indicates:
- Arterial occlusion
- Venous congestion and impaired venous return (Correct answer)
- Normal post-casting discoloration
- Superficial skin irritation from casting material
Correct answer: Venous congestion and impaired venous return
Cyanosis (blue discoloration) results from deoxygenated blood pooling in the tissues, indicating impaired venous return rather than arterial occlusion.
Question 7: When assessing the neurological status of a hand in a cast, a patient's inability to make an 'OK' sign (circle between thumb and index finger) suggests compromise of which nerve?
- Ulnar nerve
- Radial nerve
- Anterior interosseous nerve (branch of median) (Correct answer)
- Musculocutaneous nerve
Correct answer: Anterior interosseous nerve (branch of median)
The 'OK' sign tests the anterior interosseous nerve (a motor branch of the median nerve), which innervates the flexor pollicis longus and index finger flexor digitorum profundus.
OCC OCC Neurovascular Assessment & Monitoring 2
A patient with a recently applied long leg cast reports numbness of the little toe and the lateral aspect of the foot.
Which nerve is most likely compressed?