IBCC Episode 128 - ABG, VBG and Pulse Oximetry

This podcast addresses the use of arterial and venous blood gases and pulse oximetry in assessing oxygenation and ventilation in critical care. It highlights the importance of matching oxygen delivery to consumption, noting that while pulse oximetry is generally the default for monitoring oxygenation due to its non-invasive nature and continuous monitoring capabilities, arterial blood gases (ABGs) are crucial in specific situations such as poor arterial waveforms, dyshemoglobinemia, and assessing the PF ratio in ARDS patients. The discussion covers the limitations of pulse oximetry in patients with dark skin and explores the utility of venous blood gases (VBGs) as an alternative for assessing pH and ventilation, especially when the venous oxygen saturation is high, indicating low metabolic activity in the sampled limb. The hosts also discuss the perfusion index as a reflection of pulsatile blood flow, which can indicate stroke volume and vascular tone.