When a 3-year-old girl is brought into your remote emergency department after being struck by a car, she has gurgling respirations and is unconscious with a pediatric GCS of 4 (no eye opening, no verbal response, and decerebrate posturing). You need to intubate her, but the smallest endotracheal tube (ETT) you have is size 7.0 mm; she needs a 5.0 mm (ID) or smaller tube. How do you rapidly make an ETT for her?
Any hollow tubing that can go through the airway also can be used as an ETT, at least temporarily. If the tube is straight and rigid (like a rigid bronchoscope), such as a small pipe or a piece of bamboo, the patient must be kept fully sedated and, if possible, paralyzed, to avoid breaking the teeth or causing other trauma. The patient must also be in a condition to have his head extended (i.e., no neck injury).
In emergency situations, uncuffed endotracheal, cricothyrotomy, and tracheostomy tubes can be made from the wide variety of medical tubing available in hospitals and clinics. Getting tubes from these sources offers the benefits of cleanliness, various degrees of flexibility, and a variety of sizes. Two examples are the connector tubing for suction devices (Figure 1) and for chest tubes. Note, however, that while very large urethral catheters can be used for infant ETTs if their tips are cut off, their soft rubber walls may collapse.
Also, some polyvinyl tubes and heavier rubber tubes offer less flexibility than others. However, the main problem when selecting a tube to use as an improvised ETT is that the tube’s wall thickness will often be greater than that of an ETT, so the ID may be slightly smaller than desired. However, in a lifesaving emergency, you may need to use whatever is immediately available.
Most chest tubes have an ID:OD ratio similar to that of ETTs (between 2.5:4 and 3.5:5). That means that a chest tube used as the 5mm ID ETT as in this case should have an OD between 7 mm and 8 mm. Typical chest tube sizes (OD) that work appropriately as neonatal and pediatric ETTs are 16 Fr (5.3 mm OD)—similar to a 3.5 mm ETT, 20 Fr (6.7 mm), and 24 Fr (8.0 mm)—similar to a 5 to 5.5 mm ETT.
The typical chest tube for an adult ETT is 32F, which equates to about a 6.5 to 7.5 mm ETT. A 36F (12 mm OD) chest tube approximates a size 8 to 9 mm ETT and a 28F tube, about a 6 to 7 mm ETT.
When improvising ETTs, the tube’s length also needs to be considered. Cut the tube to the appropriate length for the patient. Shortening an ETT significantly reduces its resistance to airflow.
Once you make an ETT, how do you connect it to a bag-valve-mask (BVM) or ventilator? Whatever tubing is used and no matter what size is needed—from neonatal to large adult—the tube can quickly and easily be adapted to fit a standard ventilator or bag-valve connector. This technique can also be applied if a standard ETT does not fit the ventilation device being used, or if the standard adapter that fits the ventilation device is lost or broken.
Made from the nipple of a standard infant feeding bottle, this adapter is similar to a Foregger-Racine adapter and other more-complex equipment described for the same purpose. Enlarge the nipple hole so that the ventilator end of the ETT can just fit through with a tight seal (Figure 2). Push the tube through the hole so that the BVM/ventilator end is inside the nipple (Figure 3). The other, wide end of the nipple connects to the ventilation device (Figure 4). Experience shows that any size pediatric or adult ETT, or any equivalent that is being used as a makeshift endotracheal, cricothyrotomy, or tracheostomy tube, will fit.
Improvising an ETT “Cuff”
ETTs in adults work best if they are cuffed. If an adult ETT (regular or improvised) is not cuffed or if its balloon breaks, there may be a significant air leak, which may increase the chance of aspiration. To improvise an ETT cuff, use the same technique as the early anesthetists; pack the pharynx under direct vision with a wide piece of saline-soaked gauze or cloth, using Magill or similar forceps. Do not use petroleum jelly (e.g., Vaseline) or other petroleum containing products to soak the gauze, since that might cause pneumonitis.
As when packing the nose or an abscess, use only one length of packing material so that, when it is removed, there is no chance of leaving an unobserved second piece behind. Tie one end of the packing to the ETT to ensure its removal when the patient is extubated.
Despite sounds of disbelief from the staff, an appropriately sized ETT was made for the child and tested with a BVM before using it to intubate her. She did not require ventilation, only airway protection and supplemental oxygen. No packing was used around the cuff. Eight hours later, she was extubated.
Much of the material in this article is taken from Improvised Medicine: Providing Care in Extreme Environments (McGraw-Hill, 2012).