Quote from NicuGal
you shouldn't be taking them off the vent to suction, you lose pressures.
It's actually not the disconnection from the vent that causes loss of pressure/derecruitment. That is a result of suctioning itself (i.e. because you're occluding the airway -- the ETT -- with the suction catheter for the purpose of suction.)
In my unit we use a suction port on the ETT/vent circuit connection. So, we don't use in-line, but we don't have to disconnect. However we find the process is often fiddly and difficult because passing a catheter through the one way valve of the suction port is difficult and you don't tend to get as many secretions as you do when you disconnect the vent and suction.
A number of nurses on my unit recently went to a high frequency ventilation conference and attended a seminar purely on suctioning whilst kiddo is on the vent. Numerous things that they heard in this seminar were applicable to conventional ventilation. They were shown two images of lungs following suction and asked to chose which patient had been disconnected during suction and which had not. Everyone chose the worse looking, more de-recuited pair of lungs as being disconnected for suction. In fact, the opposite was true.
Suction itself causes de-recruitment, not disconnection.