ET Tube: Parts and Functions

It’s not always that student nurses get assigned in the ICU, so Ria, being assigned to go on duty there for the first time took it very seriously. She treated everything as very important in learning and in becoming a good nurse someday. As they were conducting rounds with their Clinical Instructor, Ria heard a staff nurse say, “All materials are needed for extubation, doc.”

She then notices from afar that that same staff nurse enter one cubicle with the resident on duty, approach the patient and assist the doctor on whatever she is doing. After some moves, a tube was removed from the patient and he is then given a face mask for oxygenation.

“What was that?” asked Ria.

“They were extubating the patient,” answers the CI as she approached her.

“Extubating? Extubation? As in Endotracheal Tube, what? I don’t even understand what that was about,” she says to herself as curiosity builds inside her. Tonight she is going to read about Endotracheal Tube and tonight, she is going to find some answers to her questions.

Breaking down the ET

Not often do we find intubated patients in the wards. However, it isn’t an excuse for us nurses not to know more about it. Yes, we know that ET tubes are used to provide a passage for gases to flow between a patient’s lungs and an anesthesia breathing system, that it allows one to provide positive pressure ventilation and protects the lung from contamination from gastric contents and nasopharyngeal matter such as blood.

But breaking it down, let us find time, dig a bit deeper and gain some insights about the parts and functions of the ET tube and other need-to-knows.


  • The slant you see in the end of ET tubes makes it easier to pass through the vocal cords and give you a better vision ahead of the tip.

Murphy Eye

  • At the tip of the ET tube, there is an additional hole. This one is called Murphy’s eye. It comes in really handy in certain situations such as blockage of gas flow. For example, once the main opening of the ET tube gets blocked, with the help of the Murphy’s eye, gas flow can still occur. Without it, the ET tube would be obstructed.


  • This is the inflatable region at the patient end of the ET tube. Not all ET tubes have cuffs. Once inflated, it provides a seal against the tracheal wall and prevents gases from leaking past the cuff. It also allows positive ventilation and prevents matter from entering the trachea.


  • These connectors connect the ET tube to the breathing system. Sometimes, the ET tube is not directly connected to the breathing system, but is connected to a flexible catheter mount to provide a more flexible connection.

Other need-to-knows:

  • Most ET tubes are made of plastic, specifically Polyvinyl Chloride (PVC) and may either be visually clear or opaque.
  • Since plastic is not radio opaque, plastic tubes have a line of radio opaque material that makes them more visible on a chest X Ray
  • The size of an ET refers to it internal diameter. The narrower the tube, the higher the resistance to gas flow.
  • The length of the ET is in centimeters and is measured from the end that goes into the trachea. Length marking of the tube is referred to the teeth or lips as the landmark. The longer the tube, the more prone it is to kinking and obstruction.

Sometimes, we nurses become too focused on the procedure itself that we forget to stop and consider the little details we need to know. Sometimes, it is best to breathe and get to know the parts of an equipment or material and consider their significance to the procedure, not only to gain more knowledge but also to develop a better understanding on the procedure and the things needed to be thought about to make sure that all is going well as planned.


Liane Clores, RN MAN

Currently an Intensive Care Unit nurse, pursuing a degree in Master of Arts in Nursing Major in Nursing Service Administration. Has been a contributor of Student Nurses Quarterly, Vox Populi, The Hillside Echo and the Voice of Nightingale publications. Other experience include: Medical-Surgical, Pediatric, Obstetric, Emergency and Recovery Room Nursing.

What Do You Think?