ICU Vivas · Applied physiology
Data viva — the blood gas and the oxygen delivery
A data viva applying the oxygen-delivery physiology — the DO2, the VO2, the extraction, the SvO2, the lactate, and the cause of the shock.
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Prompt
An arterial and a mixed venous gas from a shocked patient, to be interpreted via the Fick principle.
Stimulus
You are shown the gases from a shocked patient:
| Variable | Value | Normal |
|---|---|---|
| PaO2 (FiO2 0.5) | 65 mmHg | (90-110) |
| SaO2 | 92 per cent | (96-100) |
| SvO2 | 55 per cent | (65-75) |
| Hb | 75 g/L | (130-170) |
| Lactate | 4.5 mmol/L | (below 2) |
Interpret and reason through the oxygen delivery.[3]
References2ShowHide
- [3]Flick M, et al. Personalized hemodynamic management targeting preoperative baseline cardiac index. Trials, 2026.PMID 41904483
- [9]Bersten AD, Soni N (eds) Oh's Intensive Care Manual. 8th edition, Elsevier, 2018.