CNOR Patient Positioning and Physiological Monitoring 2 — Questions and Answers
Question 1: When using a fracture table for a hip procedure, the well-leg stirrup must be positioned to avoid pressure on which structure?
- Femoral vein
- Saphenous nerve at the medial knee (Correct answer)
- Obturator nerve
- Popliteal artery
Correct answer: Saphenous nerve at the medial knee
The saphenous nerve runs medially near the knee and is susceptible to compression injury from the well-leg stirrup post used with fracture tables.
Question 2: Bispectral Index (BIS) monitoring in the perioperative setting is used primarily to:
- Measure neuromuscular blockade recovery
- Assess the depth of anesthesia and reduce awareness (Correct answer)
- Monitor cerebral oxygenation during carotid procedures
- Detect intraoperative seizure activity
Correct answer: Assess the depth of anesthesia and reduce awareness
BIS monitoring processes the EEG signal to provide a numeric index of anesthetic depth, helping clinicians titrate agents and reduce the risk of intraoperative awareness.
Question 3: A patient in the supine position develops hypotension shortly after positioning. The anesthesia provider suspects aortocaval compression. This is MOST likely in which patient population?
- Obese male patients undergoing abdominal surgery
- Pregnant patients beyond 20 weeks gestation (Correct answer)
- Elderly patients with pre-existing hypertension
- Pediatric patients under 10 kg
Correct answer: Pregnant patients beyond 20 weeks gestation
In pregnant patients beyond 20 weeks, the gravid uterus can compress the inferior vena cava and aorta in the supine position, causing significant hypotension.
Question 4: During intraoperative neurophysiological monitoring (IONM) for a spinal procedure, a significant loss of motor evoked potentials (MEPs) is noted. The FIRST priority of the scrub nurse should be to:
- Immediately increase the patient's blood pressure with vasopressors
- Alert the surgeon and pause or modify the surgical maneuver (Correct answer)
- Reposition the patient to relieve spinal cord pressure
- Increase the neuromuscular blockade reversal dose
Correct answer: Alert the surgeon and pause or modify the surgical maneuver
A significant MEP change is a signal that the spinal cord may be at risk; the scrub nurse must immediately alert the surgeon so the surgical maneuver can be paused or modified.
Question 5: Compartment syndrome can occur as a complication of which surgical position when procedures are prolonged?
- Supine with arms tucked
- Lithotomy with legs elevated in stirrups (Correct answer)
- Prone with chest rolls
- Reverse Trendelenburg with shoulder braces
Correct answer: Lithotomy with legs elevated in stirrups
Lithotomy position with elevated legs can impair venous drainage and arterial perfusion in the lower extremities, leading to well-leg compartment syndrome in prolonged cases.
Question 6: A patient's peripheral oxygen saturation (SpO2) reading is consistently 2–3% lower on the right hand compared to the left hand. The anesthesia provider is concerned about which condition?
- Carbon monoxide poisoning affecting both readings
- Right subclavian artery compression or thoracic outlet issue (Correct answer)
- Peripheral vascular disease in the lower extremities
- Artifact from the surgical warming blanket
Correct answer: Right subclavian artery compression or thoracic outlet issue
A persistent SpO2 discrepancy between upper extremities suggests impaired perfusion to one limb, raising concern for subclavian artery compression or thoracic outlet syndrome in that position.
Question 7: Which layer of padding is recommended FIRST when protecting bony prominences from pressure injury during surgery?
- Foam padding directly applied to skin
- A layer of egg-crate foam over a gel pad
- Soft absorbent material (e.g., cotton batting or foam) directly against the skin (Correct answer)
- Adhesive hydrocolloid dressing applied before foam
Correct answer: Soft absorbent material (e.g., cotton batting or foam) directly against the skin
Soft, non-adhesive padding material should be applied directly against the skin first to absorb moisture and cushion the bony prominence before additional supportive layers.
CNOR Patient Positioning and Physiological Monitoring 2
When using a fracture table for a hip procedure, the well-leg stirrup must be positioned to avoid pressure on which structure?