Endotracheal intubation is a medical procedure in which a flexible plastic tube is placed through the mouth (or sometimes the nose) and into the windpipe to keep the airway open and allow a machine to help with breathing. It’s one of the most common procedures in emergency rooms, intensive care units, and operating rooms, performed whenever a patient can’t breathe adequately on their own or needs their airway protected during surgery or a medical crisis.
Why Intubation Is Performed
The core purpose is simple: guarantee that air can move in and out of the lungs. But the specific reasons vary widely. During surgery, intubation delivers anesthesia gases and keeps you breathing while you’re unconscious. In emergencies, it can be lifesaving for people experiencing respiratory failure from pneumonia, emphysema, heart failure, or a collapsed lung.
Intubation also protects the lungs from aspiration, which is when fluids like blood or stomach contents enter the airway. This is a real danger for people who’ve had a stroke, a drug overdose, or massive bleeding in the esophagus or stomach. In those situations, normal protective reflexes like coughing and swallowing may not work, and the tube acts as a sealed barrier. Less commonly, the tube is placed to clear a physical blockage from the airway or to give doctors a better view of the upper airway structures.
What the Tube Looks Like
An endotracheal tube is a clear or semi-transparent plastic tube, typically 25 to 35 centimeters long, curved to follow the natural shape of the throat. Near the tip that sits in the windpipe, there’s a small inflatable balloon called a cuff. Once the tube is in position, this cuff is filled with air to create a seal against the walls of the windpipe, preventing air from leaking around the tube and stopping fluids from slipping past into the lungs.
Tubes come in different sizes measured by their inner diameter in millimeters. Adults typically receive a tube between 7.0 and 8.0 mm, with slightly larger sizes for taller individuals. Children require much smaller tubes, and doctors use age-based formulas to estimate the right fit. One common formula for kids over two calculates tube size as the child’s age divided by four, plus four. Because these formulas aren’t perfect, medical teams always have tubes a half-size larger and smaller ready to go.
How the Procedure Works
In a planned intubation, the process follows a structured sequence. First, the patient breathes pure oxygen through a mask for several minutes. This builds up an oxygen reserve in the lungs, buying extra time during the brief period when the patient won’t be breathing on their own.
Next, medications are given through an IV. A sedative puts the patient to sleep, and a muscle relaxant causes the jaw, tongue, and vocal cords to go limp, making it easier to pass the tube. After about 60 seconds for the medications to take full effect, the doctor opens the mouth using a scissoring motion with the thumb and middle finger, then inserts a laryngoscope, a handled instrument with a lighted blade that pushes the tongue aside and lifts it to reveal the vocal cords at the entrance to the windpipe.
With the vocal cords in view, the doctor slides the endotracheal tube between them and into the windpipe, then removes the stiff internal wire (called a stylet) that helped guide the tube. The cuff is inflated, and the tube is secured to the face with tape or a holder. The entire process, when it goes smoothly, takes under a minute.
Confirming the Tube Is in the Right Place
Getting the tube into the windpipe rather than the esophagus (the food pipe, which sits right behind it) is critical. Esophageal intubation, where the tube accidentally goes into the wrong pipe, occurs in roughly 7% of intubations in critically ill patients. If it’s not caught quickly, no oxygen reaches the lungs.
The gold standard for confirming correct placement is waveform capnography, a monitor that continuously measures carbon dioxide in exhaled breath. A normal rising-and-falling CO2 pattern on the screen confirms the tube is in the windpipe, because CO2 only comes from the lungs. Older methods people might assume are reliable, like listening to the chest with a stethoscope, watching for the chest to rise, or looking for condensation inside the tube, have proven unreliable on their own. After initial confirmation, a chest X-ray is taken to verify the tube is sitting at the right depth, not too deep into one lung or too shallow near the vocal cords.
Risks and Complications
Intubation is generally safe, but it’s not risk-free, especially in critically ill or emergency patients. A study of ICU intubations found that 39% involved at least one complication. The most common was a significant drop in blood oxygen levels, occurring in about 19% of cases. Dangerous drops in blood pressure happened in nearly 10%, and aspiration of stomach contents occurred in about 6%.
One of the strongest predictors of complications is how many attempts it takes. When the tube goes in on the first try, risks are considerably lower. Needing two or more attempts more than triples the odds of a severe complication. This is why hospitals stock alternative tools, including video-assisted devices, flexible scopes, and backup airway devices, so the team can switch approaches quickly if the first method isn’t working.
Other possible complications include chipped or damaged teeth from the laryngoscope blade, minor cuts or bleeding in the mouth or throat, and, rarely, injury to the vocal cords. Most of these are short-lived, but prolonged intubation (days to weeks in the ICU) carries additional risks, including damage to the lining of the windpipe from the cuff pressing against it over time.
What Recovery Feels Like
After a short intubation, like one lasting the duration of a surgery, the tube is removed once you’re awake enough to breathe on your own and protect your airway. A sore throat is the most common complaint afterward, and it can last anywhere from a few hours to a few days. Hoarseness is also typical, caused by mild irritation or swelling of the vocal cords. These symptoms usually resolve without treatment.
Some patients experience stridor after the tube comes out, a harsh, high-pitched breathing sound caused by swelling in the airway. It sounds alarming, especially to family members, but it’s usually mild and temporary. When doctors anticipate this risk, particularly after longer intubations, they may give a steroid medication several hours before removing the tube to reduce swelling. Studies have found that a single dose prevents stridor in about 88% of patients, and multiple doses push that figure to 93%.
For patients intubated in the ICU for days or longer, the recovery process is more involved. Muscles used for breathing can weaken from disuse, and some patients need a gradual weaning process where the ventilator does progressively less work as they rebuild the ability to breathe independently. Swallowing can also be temporarily impaired, so medical teams often test swallowing function before allowing food or drink after a prolonged intubation.