Endotracheal tube cuffs can leak. Why they leak and how the leak can be fixed is a task that can challenge the anesthesiologist or ICU physician. In the manuscript “Endotracheal Tube Cuff Leaks: Causes, Consequences, and Management,” Drs. Mohammad El-Orbany, Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin, and M. Ramez Salem, Department of Anesthesiology, Advocate Illinois Masonic Medical Center, Chicago, Illinois, reviewed this problem.
Why do endotracheal tubes leak?
Endotracheal tubes can leak either because not enough air was inserted into the cuff. This is usually the first item on every anesthesiologists checklist for a leaking endotracheal tube. They can also leak if nitrous oxide had been used for a period and was then discontinued. Endotracheal tube cuffs should be filled with air so that there is no leak at an airway pressure of 20 cm H2O and then intermittently checked to make sure that is still the case. Endotracheal tubes can also migrate cephalad, out of the trachea, particularly in ICUs. A gastric tube can also inadvertently be placed between the tube and the trachea. If the gastric tube is connected to suction, the bellows of the ventilator will probably collapse. An endotracheal tube too small for the trachea may leak. The inflation valve of the cuff can become incompetent because of a defect, due to either the manufacturer or the syringe used to inflate the cuff. The pilot balloon and/or tubing can become damaged, and the cuff itself can have a defect.
What’s the problem with having a leaky endotracheal tube cuff?
With the leak, there can be extra noise, probably of little consequence in the noisy clinical environment. A large leak can result in inadequate ventilation, a more serious concern. Gastric contents can come up from the stomach and enter the trachea around the cuff leak. This may lead to aspiration pneumonia. Large quantities of bilious stomach contents may even prove fatal.
When an anesthetic is going through the endotracheal tube, a leak can result in OR anesthetic pollution. Since the operating room is receiving the anesthetic vapor intended for the patient, the patient may be inadequately anesthetized. In the case of one-lung ventilation, leak around the bronchial cuff can result in a failure of separate lung ventilation. Patients who are particularly dependent on adequate ventilation can develop hypoxemia, hypercarbia, and respiratory failure.
How can cuff leaks be fixed?
Obviously the endotracheal tube can be replaced. However, there are instances when it may be difficult to insert the endotracheal tube; the stress of re-inserting the tube may be high (e.g., for patients with neurologic or elevated intracranial pressure or coronary artery disease); or lack of ventilation might be too tenuous, or, in special instances such as during surgery around the airway, if the patient is prone, or if the airway is edematous or traumatized, such that other solutions to fix the problem are needed.
Pharyngeal packing can help reduce airway leak. If the leak is due to problems with the pilot balloon valve, a stopcock can be inserted, though some newer stopcocks have shortened male ends. The pilot balloon can be can be cut and a 22-guage angiocath can be inserted into the tubing. If the cuff is leaking, gas flow can be continuously insufflated.
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Airway management is more generally discussed on OpenAnesthesia.
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