Chapter 29 — Self-Check Quiz

20 questions. Answers with explanations at the end. Aim for 16+.

Questions

1. Ivor's nine days of near-starvation resulted from:

• a) Negligence by an identifiable individual
• b) Nine individually reasonable decisions, with nobody positioned to see the total
• c) A shortage of food
• d) His refusal to eat

2. The commonest reason nutritional screening fails on admission is:

• a) The tools are inaccurate
• b) Weight isn't measured — you cannot screen without it
• c) Patients decline
• d) It takes too long

3. Modern preoperative fasting guidance permits:

• a) Nil by mouth from midnight
• b) Clear fluids up to about 2 hours and a light meal up to about 6 hours before
• c) Nothing for 24 hours
• d) Unrestricted eating

4. Bed rest causes measurable loss of muscle mass and strength within:

• a) Three months
• b) Days — faster in older adults, accelerated by inflammation
• c) Six weeks
• d) It does not

5. The governing principle for choosing a feeding route is:

• a) Parenteral is most reliable, so use it first
• b) If the gut works, use it — and the least invasive adequate route wins
• c) Always use a tube
• d) Oral supplements before food

6. Oral nutritional supplements work best when:

• a) Taken instead of meals
• b) Taken between meals, as an addition to food
• c) Left on the locker
• d) Given only at night

7. Nasogastric tube position must be confirmed by:

• a) The whoosh test
• b) Aspirate pH testing (pH ≤5.5) and/or radiographic confirmation by someone competent to interpret it
• c) Bubbling in water
• d) Asking the patient

8. PEG feeding in advanced dementia has been shown to:

• a) Prolong survival
• b) None of these — it does not prolong survival, prevent aspiration, improve pressure ulcers, function or comfort
• c) Prevent aspiration pneumonia
• d) Improve comfort

9. Aspiration continues after PEG placement in dementia because:

• a) The tube leaks
• b) Aspiration is largely of saliva and refluxed gastric contents, not food
• c) The feed is too thin
• d) Patients pull the tube out

10. The mechanism of refeeding syndrome begins with:

• a) Excess protein
• b) An insulin surge driving phosphate, potassium and magnesium rapidly into cells while serum levels crash
• c) Dehydration
• d) Vitamin D deficiency

11. The hallmark electrolyte abnormality in refeeding syndrome is:

• a) Hypernatraemia
• b) Hypophosphataemia
• c) Hypercalcaemia
• d) Hyperkalaemia

12. Before feeding a person at high refeeding risk you must give:

• a) Potassium only
• b) Thiamine — before feeding, not with it — plus B vitamins
• c) Nothing special
• d) A full-calorie feed to correct the deficit quickly

13. In the highest-risk patients, feeding commonly starts at approximately:

• a) Full estimated requirements
• b) 5–10 kcal/kg/day, increasing gradually over days
• c) 30 kcal/kg/day
• d) Nothing for a further week

14. Large trials in critical illness found that early full-dose feeding:

• a) Substantially improved survival
• b) Did not improve outcomes, and in the case of early supplemental parenteral nutrition was associated with worse recovery than later initiation
• c) Was never tested
• d) Halved mortality

15. One proposed explanation is that critically ill patients:

• a) Cannot absorb anything
• b) Generate substantial endogenous energy from their own tissue, so added feeding produces overfeeding
• c) Have no protein requirement
• d) Metabolize nothing

16. The EFFORT Protein trial found that higher protein delivery in critical illness:

• a) Clearly improved outcomes
• b) Did not improve outcomes, with signals of possible harm in some subgroups including acute kidney injury
• c) Was universally beneficial
• d) Reduced ICU stay by half

17. The correct advice about warfarin and vitamin K is:

• a) Avoid green vegetables
• b) Keep intake consistent — erratic intake destabilizes the INR
• c) Eat as much as possible
• d) Vitamin K is irrelevant

18. In an acutely unwell inpatient eating poorly, a restrictive "diabetic diet" is:

• a) Essential
• b) Usually the wrong trade — adjust the medication instead
• c) The only option
• d) Required by law

19. §29.13's key distinction is that a dying person:

• a) Is dying because they stopped eating
• b) Has stopped eating because they are dying — not the reverse
• c) Should always be tube fed
• d) Feels hunger acutely

20. §29.11 identifies the most dangerous sentence in the book as:

• a) "Eat more protein"
• b) "Eat less"
• c) "Avoid ultra-processed food"
• d) "Take a supplement"

Answers

1. b) Nine individually reasonable decisions. ⚠️ Fasting for theatre is correct, bumping a list happens, nausea is expected, X-ray had to be done. Nobody decided to starve him — and no single person was positioned to see the total. That is what clinical malnutrition looks like. §29 hook.

2. b) Weight isn't measured. ⚠️ Scales absent, broken, or the patient can't stand. You cannot screen without a weight. (The others: forms compete, nobody owns the result, and nutrition has no monitor — nothing alarms.) §29.2.

3. b) Clear fluids ~2 h, light meal ~6 h. ⚠️ "Nil by mouth from midnight" persists widely, is not supported, and produces discomfort, dehydration, insulin resistance and misery with no added safety. §29.3, §29.9.

4. b) Days. ⚠️ And acute illness accelerates it through inflammation-driven catabolism, on top of anabolic resistance in older adults. Which is why nutrition and mobilization are the same intervention: protein without loading does much less, and loading without protein has nothing to build with. §29.3b.

5. b) If the gut works, use it. Food first — fortified, with help, barriers fixed — then ONS, then enteral, then parenteral. §29.4.

6. b) Between meals, as an addition. ⚠️ "Sip feeds left on the locker, untouched, for three days" is the standard failure mode. §29.4.

7. b) pH ≤5.5 and/or radiographic confirmation. ⚠️ Misplacement into the lung is a recognized never event and has killed people. The whoosh test and bubbling in water are not valid and were abandoned for good reason. §29.5.

8. b) None of these. ⚠️ Most professional bodies now advise against it, and recommend careful hand feeding instead — assisted, unhurried, accepting limited intake. §29.5.

9. b) Saliva and refluxed gastric contents. ⚠️ Which is why bypassing the mouth doesn't prevent it. And the tube adds burdens: procedural risk, restraint to stop it being pulled out, and loss of the human contact of being fed. §29.5.

10. b) An insulin surge. ⚠️ Prolonged starvation depletes INTRACELLULAR phosphate, potassium and magnesium while serum levels stay normal. Feed carbohydrate → insulin surges → those electrolytes move rapidly into cells → serum crashes. And thiamine is consumed by carbohydrate metabolism when there isn't any. §29.7.

11. b) Hypophosphataemia. ⚠️ It can develop within 24–72 hours of starting feeding. The consequences include cardiac arrhythmia, cardiac and respiratory failure, rhabdomyolysis, seizures, Wernicke's encephalopathy and death. ⚠️ The syndrome was described in liberated prisoners of war and famine survivors who died after being fed — people survived starvation and were killed by food. §29.7.

12. b) Thiamine, before feeding. ⚠️ Not with it. Before it. Plus B vitamins, continued through the early days. §29.7.

13. b) 5–10 kcal/kg/day. ⚠️ Start low, go slow. Check phosphate, potassium and magnesium before feeding and daily thereafter, replace aggressively — and do NOT wait for normal levels before starting. ⚠️ The instinct "this person is starving, feed them properly" is exactly the instinct that causes the harm. §29.7.

14. b) Did not improve outcomes. ⚠️ EPaNIC found LATE initiation of supplemental parenteral nutrition was associated with better recovery than early; EDEN found trophic feeding no worse than full in ARDS; TARGET found no mortality benefit from higher energy delivery. Current consensus: start enteral early but LOW, advance gradually across the first week, don't chase targets in the acute phase. §29.8.

15. b) Endogenous energy production. ⚠️ A critically ill patient generates substantial energy from their own tissue, so feeding on top produces overfeeding even when the delivered amount looks like a deficit. (Also proposed: suppression of autophagy — a much better-supported use of that mechanism than Chapter 21's fasting literature made — and hyperglycaemia.) §29.8.

16. b) No improvement, possible harm in some subgroups. ⚠️ Optimal protein in critical illness is genuinely contested and is held at LOW confidence in this chapter. §29.8.

17. b) Consistency. ⚠️ The row most often got wrong in both directions. Patients are told to avoid green vegetables; avoidance costs them folate, fibre and INR stability. §29.10.

18. b) Usually the wrong trade. ⚠️ The restriction reduces intake in someone already not eating enough, to improve a reading that could be managed by adjusting medication. Chapter 26's tiers: glycaemia is rapidly correctable by other means; lean mass loss is not. §29.12.

19. b) Stopped eating because they are dying. ⚠️ Reversing the causality is intuitive, almost universal among families, and leads to requests for feeding that cannot help and may hurt — fluid overload, secretions, oedema, aspiration. What is appropriate is comfort feeding and mouth care. ⚠️ And the family's distress deserves addressing directly: feeding someone is what you do when you love them. §29.13.

20. b) "Eat less." ⚠️ §29.11's inversion table: almost all population dietary advice is calibrated for a person whose problem is EXCESS, and a substantial number of people in a hospital have the opposite problem. Energy density UP. Fortify everything. Sugar is irrelevant. Oral supplements ARE ultra-processed and they save lives. §29.11.

Scoring

Three items worth checking regardless of score.

Questions 10–13. ⚠️ Refeeding syndrome is the one place in this book where enthusiastic, well-intentioned feeding kills people. If any of those four were wrong, reread §29.7 properly.

Question 14. ⚠️ If you predicted that early full feeding helps, you reasoned correctly from clean physiology and the trials disagreed. That is the chapter's epistemic lesson, not a failure.

Question 20. ⚠️ The sentence that closes Part V — and the reason the last seven chapters kept inverting.