NACE Physiological Adaptation 5 — Questions and Answers
Question 1: A patient with cirrhosis develops asterixis, confusion, and elevated ammonia levels. Which physiological process is occurring?
- Cerebral infarction from portal hypertension
- Hepatic encephalopathy from impaired ammonia detoxification (Correct answer)
- Wernicke's encephalopathy from thiamine deficiency
- Subdural hematoma from coagulopathy
Correct answer: Hepatic encephalopathy from impaired ammonia detoxification
Hepatic encephalopathy results from the failing liver's inability to convert ammonia to urea, allowing ammonia to cross the blood-brain barrier and impair neurological function.
Question 2: A patient on mechanical ventilation has a PaCO2 of 55 mmHg and pH of 7.28. The ventilator rate is 12 breaths/min. What adjustment would correct the respiratory acidosis?
- Decrease the tidal volume
- Increase the FiO2
- Increase the respiratory rate (Correct answer)
- Add PEEP to the circuit
Correct answer: Increase the respiratory rate
Increasing the respiratory rate increases minute ventilation, eliminating more CO2 and correcting respiratory acidosis.
Question 3: A patient develops compartment syndrome in the left leg after a tibial fracture. Which assessment finding is most diagnostic?
- Skin discoloration and loss of peripheral pulse
- Pain out of proportion to injury unrelieved by opioids, worsened with passive stretch (Correct answer)
- 2+ pitting edema extending to the knee
- Decreased sensation in the plantar surface only
Correct answer: Pain out of proportion to injury unrelieved by opioids, worsened with passive stretch
Pain disproportionate to the injury that worsens with passive muscle stretching is the hallmark early sign of compartment syndrome due to elevated intracompartmental pressure.
Question 4: A patient with heart failure is prescribed furosemide. Which electrolyte imbalance is the priority concern?
- Hypernatremia
- Hyperkalemia
- Hypokalemia (Correct answer)
- Hypercalcemia
Correct answer: Hypokalemia
Loop diuretics like furosemide inhibit sodium-potassium-chloride reabsorption in the loop of Henle, causing significant potassium wasting and hypokalemia.
Question 5: A patient with Addison's disease presents with severe hypotension, hyponatremia, and hyperkalemia. Which pathophysiological mechanism explains these findings?
- Excess cortisol causing fluid shifts
- Aldosterone deficiency impairing sodium retention and potassium excretion (Correct answer)
- ADH excess causing water retention
- Epinephrine excess stimulating the renin-angiotensin system
Correct answer: Aldosterone deficiency impairing sodium retention and potassium excretion
Aldosterone deficiency in Addison's disease prevents sodium reabsorption and potassium excretion in the kidney, leading to hyponatremia, hyperkalemia, and volume depletion.
Question 6: A patient with severe burns covering 40% TBSA is in the first 24 hours post-injury. Which physiological change requires the most aggressive fluid resuscitation?
- Increased insensible water loss through eschar
- Massive fluid shift from intravascular to interstitial space due to increased capillary permeability (Correct answer)
- Hemolysis of red blood cells causing anemia
- Decreased cardiac output from pain-induced vasoconstriction
Correct answer: Massive fluid shift from intravascular to interstitial space due to increased capillary permeability
Burn injury causes massive capillary leak syndrome, shifting large volumes from the intravascular to interstitial compartment, causing hypovolemic shock within hours.
Question 7: A post-operative patient develops a fever of 38.9°C on day 3 after abdominal surgery. Which is the most likely physiological cause?
- Pulmonary atelectasis resolving
- Wound infection establishing at the surgical site (Correct answer)
- Deep vein thrombosis in the lower extremities
- Urinary tract infection from catheterization
Correct answer: Wound infection establishing at the surgical site
Wound infection typically presents between post-operative days 3-5 as bacteria proliferate and the inflammatory response produces systemic fever.
NACE Physiological Adaptation 5
A patient with cirrhosis develops asterixis, confusion, and elevated ammonia levels.
Which physiological process is occurring?