Tracheal Tube - Endotracheal Tube

Endotracheal Tube

Most endotracheal tubes today are constructed of polyvinyl chloride, but specialty tubes constructed of silicone rubber, latex rubber, or stainless steel are also widely available. Most tubes have an inflatable cuff to seal the trachea and bronchial tree against air leakage and aspiration of gastric contents, blood, secretions, and other fluids. Uncuffed tubes are also available, though their use is limited mostly to pediatric patients (in small children, the cricoid cartilage, the narrowest portion of the pediatric airway, often provides an adequate seal for mechanical ventilation).

Types of endotracheal tube include oral or nasal, cuffed or uncuffed, preformed (e.g. RAE (Ring, Adair, and Elwyn) tube), reinforced tubes, and double-lumen endobronchial tubes. For human use, tubes range in size from 2 to 10.5 mm in internal diameter (ID). The size is chosen based on the patient's body size, with the smaller sizes being used for pediatric and neonatal patients. Tubes larger than 6 mm ID usually have an inflatable cuff. Originally made from red rubber, most modern tubes are made from polyvinyl chloride. Those placed in a laser field may be flexometallic. Robertshaw (and others) developed double-lumen endo-bronchial tubes for Thoracic surgery. These allow single-lung ventilation while the other lung is collapsed to make surgery easier. The deflated lung is re-inflated as surgery finishes to check for fistulas (tears). Another type of endotracheal tube has a small second lumen opening above the inflatable cuff, which can be used for suction of the nasopharngeal area and above the cuff to aid extubation (removal). This allows suctioning of secretions which sit above the cuff which helps reduce the risk of chest infections in long-term intubated patients.

The "armored" endotracheal tubes are cuffed, wire-reinforced, silicone rubber tubes which are quite flexible but yet difficult to compress or kink. This can make them useful for situations in which the trachea is anticipated to remain intubated for a prolonged duration, or if the neck is to remain flexed during surgery. Polyvinyl chloride tubes are relatively stiff in comparison. Preformed tubes (such as the oral and nasal RAE tubes, named after the inventors Ring, Adair and Elwyn) are also widely available for special applications. These may also be constructed of polyvinyl chloride or wire-reinforced silicone rubber. Other tubes (such as the Bivona Fome-Cuf tube) are designed specifically for use in laser surgery in and around the airway. Various types of double-lumen endotracheal (actually, endobronchial) tubes have been developed (Carlens, White, Robertshaw, etc.) for ventilating each lung independently—this is useful during pulmonary and other thoracic operations.