Anaes Vivas · Applied cardiovascular & respiratory physiology
Data viva — the oxyhaemoglobin dissociation curve and its shifts
A data viva on the oxyhaemoglobin dissociation curve — the sigmoid shape (the cooperative binding), the P50 (about 26-27 mmHg), the steep portion (the saturation falls rapidly below 60 mmHg), and the right (the 2,3-DPG, the acidosis, the fever) and the left (the alkalosis, the hypothermia, the stored blood) shifts.
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ANZCAFRCAABAEDAIC
Prompt
The oxyhaemoglobin dissociation curve (the sigmoid SaO2-versus-PaO2 plot) with the P50 marked, and two shifted curves (one left, one right). Interpret the curve and the shifts.
Stimulus
The oxyhaemoglobin dissociation curve is shown — the sigmoid plot of the SaO2 against the PaO2 — with the P50 marked at about 26 to 27 mmHg. Two further curves are shown: one shifted LEFT and one shifted RIGHT. Interpret the shape, the P50, and the shifts.
References3ShowHide
- [6]Jaafar LS. 2,3-Diphosphoglycerate: the forgotten metabolic regulator of oxygen affinity. Br J Nutr, 2025.PMID 41070558
- [7]Kumar A, et al. Effects of inhaled anaesthetic agents on the oxygen dissociation curve. J Perioper Pract, 2025.PMID 39991860
- [41070559]Bersten AD, Soni N (eds) Oh's Intensive Care Manual. 8th edition, Elsevier, 2018.