Wednesday January 16, 2008
Scenario: They ask you in ICU to evaluate this 22 yo previously healthy pt. after a craniotomy for GSW, who was supposed to get extubated this am but unexpectedly his pre-extubation paO2 is only 60. Also, "something happened" with his ETT. It was reported to you that earlier RT has to push it back. Patient was left on CPAP.
You look at the pt. and see the ETT goes across his mouth from one side to the other and is at 23 cm at the lips. He appears to be biting on the ETT a little and is a little sleepy but cooperative. SpO2 is 95 % on 40 % FiO2. You consider the cuff might be broken and try inflating it and it seems to be taking quite a bit of air. Eventually it seems to stay firm but you think there might be a very slow leak, like there is sometimes from minuscule holes. You think there may be some atelectasis that needs to be opened so you try the Ambu bag but the bag cannot hold the lungs inflated ! Actually you hear the air coming out the mouth. And as you inflate the cuff a little more still and the patient desaturates:
what happened ?
Answer: Patient had cough up the ET tube and is above the cords.
The pre-extubation paO2 was low as he was getting some room air from around the ETT by a Venturi effect. The T-E fistula is another possibility. As patient was extubated his saturation jumped to 100% - indeed he was ready for extubation. Patient desaturated with ambu bag as he got hypoxic he bit the ETT closed. Also, as you occluded the air coming in from around the cuff (balloon) - by inflating more air inside - he lost the venturi effect too.
Note: Objective of above question is to raise awareness about importance of secure and patent airway. You may feel this is a classic (or common & easy) scenario though but even seasoned intensivist can get scared and confused a little when facing it.
Moral of the story: Airway is no place to fool around (as in above scenario RT by pushing ETT inward and later physician by inflating more air in cuff and by ambu bagging - made situation worse).
Above pearl is contributed by :
Ivan Hronek MD at SFMC, Los Angeles