What goes wrong when PO₂ and PCO₂ leave their normal range, and the named breathing patterns that give the diagnosis away at the bedside. Your book says plainly that long questions are not set from this chapter: examiners take asphyxia, hypercapnia, hypocapnia, periodic breathing and Cheyne-Stokes respiration as short notes, and the viva lives on definitions — what is Kussmaul breathing, what is Biot’s respiration, and in what conditions is each seen.
Topics, in the book’s order
- Asphyxia, hypercapnia and hypocapnia · pp. 957–958 · asked 6 times
- Abnormal breathing patterns · pp. 958–960 · asked 5 times
When you’ve read them: Quiz 112 · Respiration in Abnormal Conditions and Abnormal Respirations, 15 questions.
After this chapter you should be able to
- define asphyxia, hypocapnia and hypercapnia, and list the causes of each
- explain the physiological basis of the abnormalities each of them produces
- describe the respiratory changes in drowning, respiratory acidosis and respiratory alkalosis
- define periodic breathing, give its causes and explain the mechanism behind it
- explain the physiological basis of Kussmaul breathing, Biot’s respiration and sleep apnea syndrome
Viva checklist
- What asphyxia is, and why it is not the same as hypoxia alone
- The three stages of asphyxia in order, and roughly how long each lasts
- The features of each stage, and which one carries convulsions and a rise in blood pressure
- Definition of hypercapnia, and its causes
- How much CO₂ production rises for each 1°C of fever
- Effects of hypercapnia, and the plasma bicarbonate of profound hypercapnia
- Type I versus type II respiratory failure
- Definition of hypocapnia, and the PCO₂ and PO₂ reached in voluntary hyperventilation
- What hypocapnia does to cerebral blood flow, and why tetany can appear
- Respiratory acidosis and respiratory alkalosis: cause, and how each is compensated
- Fresh-water versus sea-water drowning, and why some victims have dry lungs
- What periodic breathing is, what Cheyne-Stokes respiration is, and where it is seen
- Kussmaul breathing and Biot’s respiration: the pattern, and the conditions behind each
- Sleep apnea syndrome, sudden infant death syndrome, hysteric hyperpnea and Ondine’s curse, in a line each