Art.Nr.: 138-L-PA-7
In pulmonary physiology, shunt refers to the phenomenon that blood flows through the lungs, but does not take part in gas exchange. In young, healthy, spontaneously breathing patients, the shunt fraction (i.e. amount) is around 5%. Pathological factors such as pneumonia, ARDS, mechanical ventilation, obesity and non-physiological positions increase the shunt fraction and result primarily in hypoxemia and secondarily in hypercapnia. The berggren formula is an academic method to calculate the shunt fraction. This can be done most quickly and with clinically sufficient accuracy at the bedside by comparing arterial CO2 (paCO2) and end-tidal CO2 (etCO2). https://pubmed.ncbi.nlm.nih.gov/35323050/
