You are intubating a 68 year old male in the emergency department for hypoxic respiratory failure. After direct visualization of the endotracheal tube passing through the vocal cords you connect the colorimetric end tidal CO2 detector and begin to ventilate with a BVM. After delivery of 3 breaths via BVM there is no color change and the respiratory therapist is concerned the ETT is not in the trachea. After how many breaths can you reliably determine whether the tube is in the trachea using a qualitative end tidal CO2 detector? 

A. 2 

B. 3 

C. 4 

D. 5 

E. 6 

Answer: E. You should wait 6 breaths to determine if there is appropriate color change. Any less than this and you may prematurely remove a properly placed ETT. Remember in certain pathologic states of low pulmonary perfusion such as cardiac arrest you may not get immediate color change on the qualitative end tidal CO2 detector