Tracheal Suctioning

If the foal is unable to generate an effective cough or if coughing is ineffective at removing airway secretions, they may be removed by tracheal suctioning. This procedure is not without risk. Aseptic techniques and short time intervals are required. Cardiac arrhythmias may occur.

I. Pressures

1. Safest pressure ranges for suction equipment range between 60 and 150 mmHg. The lowest pressure and flow rate that will effectively aspirate secretions from the airway should be used.

II. Catheters

1. Suction catheters should be soft and flexible in order to minimize epithelial trauma during suctioning, and long enough to pass the end of the endotracheal tube.
2. Suction catheters should have more than one hole in their tip to prevent excessive attraction of the catheter to the tracheal wall. When this occurs an epithelial plug is sucked into the hole and it is likely to be ripped away when the catheter is withdrawn.
3. The suction catheter should have as large a lumen as possible to facilitate the removal of thick secretions.
4. The outside diameter of the catheter should be no larger than 50% of the inside diameter of the smallest portion of the airway through which the catheter is placed.

1. The air which is suctioned through the catheter comes from the room and must be able to flow freely down along the outside of the catheter. If this does not occur excessive reductions in intrapulmonary pressure will occur which increase the magnitude of the small airway and alveolar collapse.

5. The suction catheter should have a proximal thumb hole so that suction can be applied in a controlled manner.
6. The tracheal suctioning procedure must be aseptic to prevent contamination of the lower respiratory tract.

1. Trauma may be secondary to excessive manipulation of the catheter within the trachea or excessive attraction of the catheter to the tracheal wall.

III. Technique of Tracheal Suctioning

1. The airway should be well humidified, either by nebulization or by the direct installation of 2-5 ml of saline, immediately prior to the suctioning procedure.
2. If the foal is not receiving continuous oxygen, supplemental pre-oxygenation may help minimize suctioning-induced hypoxemia.
3. Mobilization of peripheral secretions to the central airways by postural drainage and percussion just prior to suctioning may improve the results of the suctioning procedure.
4. Gently insert the sterile catheter into the trachea as far as it will advance (without applying suction) with a sterile gloved hand.
5. Suction is applied while the catheter is removed. The negative pressure should not be applied to the airway for more than a total of 10 seconds to minimize the development of airway collapse and hypoxemia.
6. The catheter is withdrawn with a winding motion of the hand.
7. The suctioning procedure should cease immediately if excessive patient discomfort or restlessness, or changes in cardiac or respiratory rhythm occur.
8. The foal should be manually hyperinflated with 100% O2 following the suctioning procedure to alleviate small airway collapse and hypoxemia.
9. The foal should breathe an enriched oxygen mixture for several minutes following the procedure.
10. The entire procedure may be repeated several times at each interval if necessary and should be repeated at approximately 2 hour intervals or sooner if secretions accumulate more rapidly.