Intubation is used to keep a person’s airway open and deliver oxygen when they cannot breathe adequately on their own. This includes planned situations like surgery under general anesthesia and emergencies like respiratory failure, severe trauma, or loss of consciousness. A flexible plastic tube is placed through the mouth (or sometimes the nose) into the windpipe, connecting the lungs to a ventilator or other breathing device.
Surgery and General Anesthesia
The most common planned use of intubation is during surgery. General anesthesia involves medications that put you into a deep, unconscious state and paralyze your muscles, including the ones you use to breathe. Without an endotracheal tube in place, your airway could collapse or your lungs could stop moving air entirely. The tube ensures a steady flow of oxygen and anesthetic gases throughout the procedure.
Intubation during surgery also protects against aspiration, which is when stomach contents travel up and enter the lungs. This can cause serious pneumonia. The tube has a small inflatable cuff near its tip that seals the windpipe, creating a barrier between the digestive tract and the lungs. For shorter or less invasive surgeries, anesthesiologists sometimes use a laryngeal mask airway (LMA) instead. This device sits above the vocal cords rather than passing through them, which reduces throat irritation. LMAs work well for procedures lasting two hours or more in patients who haven’t recently eaten and aren’t at high aspiration risk.
Respiratory Failure
When someone’s lungs can no longer take in enough oxygen or expel enough carbon dioxide, intubation connects them to a mechanical ventilator that does the work for them. This happens in conditions like severe pneumonia, acute respiratory distress syndrome (ARDS), chronic lung disease flare-ups, and drug overdoses that suppress breathing. Doctors assess two main problems: whether oxygen levels in the blood are dangerously low, and whether carbon dioxide is building up because the lungs aren’t clearing it fast enough. Either situation can require intubation.
Trauma and Altered Consciousness
In emergency and trauma settings, intubation is often necessary when a patient loses the ability to protect their own airway. A conscious, alert person naturally keeps the tongue, throat muscles, and reflexes working to prevent choking. When consciousness drops, those protective reflexes weaken or disappear.
Emergency teams use the Glasgow Coma Scale to measure how responsive a person is, scoring eye opening, verbal responses, and physical movement on a scale from 3 to 15. A score of 8 or below generally triggers intubation because the patient can no longer reliably keep their airway clear. Scores in the 7 to 9 range also correlate with the most technically difficult intubations, which means the medical team needs to be especially prepared.
Other emergency scenarios that call for intubation include airway obstruction from swelling, burns, or allergic reactions; penetrating injuries to the neck or chest; and cardiac arrest, where breathing has stopped entirely.
How the Procedure Works
In an emergency, the process often follows a protocol called rapid sequence intubation. A fast-acting sedative is given intravenously to induce unconsciousness, followed immediately by a muscle relaxant that temporarily paralyzes the throat and jaw muscles. This combination creates a brief window, usually under a minute, for the tube to be placed. The most commonly used sedative in emergency departments is etomidate, used in roughly 89% of rapid sequence intubations.
The doctor uses a laryngoscope, a lighted blade-shaped instrument, to lift the tongue and visualize the vocal cords. The endotracheal tube is then guided between the cords and into the windpipe. In adults, tubes typically have an internal diameter of 7.0 to 8.0 millimeters. Correct placement is confirmed by listening to both lungs with a stethoscope and checking carbon dioxide levels in exhaled air. During planned surgeries, the process is essentially the same but performed in a more controlled environment with more time to prepare.
Differences in Children
Intubating infants and children requires different techniques because their anatomy is not simply a smaller version of an adult’s. Newborns have proportionally large heads, short necks, small mouths, and small lower jaws, all of which make airway management more challenging. The voice box sits higher in the neck (around the third or fourth vertebra, compared to the sixth in adults) and tilts at a steeper angle. The area just below the vocal cords is the narrowest part of a child’s airway and the most vulnerable to damage from the tube, which can cause scarring and narrowing if sizing or technique isn’t carefully managed.
Risks and Complications
Intubation is generally safe, but it does carry risks, particularly when it lasts for extended periods. In a study of 200 surgical patients, 2.5% had some form of laryngeal injury after intubation. These injuries included vocal cord bruising, small granulomas (tissue growths), and arytenoid dislocation, which affects one of the small cartilages that controls the vocal cords. Most of these injuries healed within three to six weeks. Permanent vocal cord paralysis occurred in 0.5% of patients, and nerve damage to the vocal cords is reported at a rate of roughly 0.1% to 0.2% across larger studies.
Sore throat and hoarseness are the most common complaints after the tube is removed. These typically resolve within a few days. A more serious long-term risk is ventilator-associated pneumonia (VAP), a lung infection that can develop after 48 hours on a ventilator. About 1.8% of all mechanically ventilated hospital patients develop VAP, though rates have been declining over the past decade thanks to better prevention practices like elevating the head of the bed and regular oral care.
Coming Off the Ventilator
Removing the tube, called extubation, isn’t as simple as pulling it out once a patient seems better. Doctors evaluate four things, sometimes remembered by the acronym MOVE: mental status, oxygenation, ventilation, and expectoration (the ability to cough and clear secretions). The patient needs to be alert enough to protect their own airway, typically scoring above 8 on the Glasgow Coma Scale, and able to produce a strong cough.
Before the tube comes out, most patients undergo a spontaneous breathing trial. The ventilator support is dialed back so the patient breathes mostly on their own for a set period, usually 30 minutes to two hours. Doctors monitor whether breathing stays steady and efficient. A cuff-leak test may also be performed, where the seal around the tube is deflated to check whether air can pass around it freely, suggesting the airway isn’t swollen shut. If the patient passes these tests, the tube is removed and they’re monitored closely for any signs of breathing difficulty in the hours that follow.