Q: How many breaths should be allowed after intubation before accepting "change of color" on end-tidal carbon dioxide (EtCO2) as a proper placement of Endotracheal tube (ETT)?
Answer: 5 or more
GI tract (esophagus) may emit detectable amounts of CO2 during the first few positive pressure breaths. 5 or more exhalations with a consistent "color change" (usually purple to yellow) should be allowed before declaring proper placement of Endotracheal tube (ETT). To note, this is not applicable to patients who are getting intubated during full cardiac arrest, as due to absence of spontaneous circulation there will be no gas exchange and no detectable EtCO2.