13 Suctioning the Airway

Note 1: This book is written to cover every item listed as testable on the Entry Level Examination (ELE), Written Registry Examination (WRE), and Clinical Simulation Examination (CSE).

The listed code for each item is taken from the National Board for Respiratory Care’s (NBRC) Summary Content Outline for CRT (Certified Respiratory Therapist) and Written RRT (Registered Respiratory Therapist) Examinations (http://evolve.elsevier.com/Sills/resptherapist/). For example, if an item is testable on both the ELE and WRE, it is shown simply as (Code: …). If an item is testable only on the ELE, it is shown as (ELE code: …). If an item is testable only on the WRE, it is shown as (WRE code: …).

Following each item’s code, the difficulty level is indicated for the questions on that item on the ELE and WRE. (See the Introduction for a full explanation of the three difficulty levels.) Recall [R] level questions typically expect the exam taker to recall factual information. Application [Ap] level questions are more difficult, because the exam taker may have to apply factual information to a clinical situation. Analysis [An] level questions are the most challenging, because the exam taker may have to use critical thinking to evaluate patient data to make a clinical decision.

Note 2: A review of the most recent versions of the Entry Level Examination (ELE) has shown that an average of 4 questions (out of 140), or 3% of the exam, will cover suctioning of the airway. A review of the most recent versions of the Written Registry Examination (WRE) has shown that an average of 3 questions (out of 100), or 3% of the exam, will cover suctioning of the airway. The Clinical Simulation Examination (CSE) is comprehensive and may include everything that an advanced respiratory therapist should know.

MODULE A

Oropharyngeal suction devices

1. Manipulate suctioning devices by order or protocol (ELE code: IIA8) [ELE Difficulty: R, Ap, An]

2. Suction catheters

Suctioning catheters are used to remove secretions and foreign material from the trachea. They come sterile and individually packaged. It is highly recommended that the outer diameter (OD) of the catheter be no more than one-half the inner diameter (ID) of the airway that it is passing through. This guideline is intended to minimize obstruction of the airway, so that the patient is able to breathe around the catheter.

Exam Hint 13-1 (ELE, WRE)

Remember that the outer diameter of the suction catheter should be no more than one half the inner diameter of the endotracheal or tracheostomy tube.

Table 13-1 presents the recommended suction catheter sizes for the various endotracheal or tracheostomy tubes. The practitioner also can easily compare the relative sizes of the tube and suction catheter at the bedside before suctioning. Suction catheters are sized by the French (Fr) scale of the OD. Endotracheal and tracheostomy tubes are sized by ID and OD in millimeters and often by OD in French. Review Table 12-1 if necessary.

TABLE 13-1 Recommended Suction Catheter French Sizes for Endotracheal and Tracheostomy Tubes ^*

Age	Tube Internal Diameter (mm)	Size of Suction Catheter (Fr)
NEWBORN
1,000 g	2.5	5
1,000-2,000 g	3	6
2,000-3,000	3.5	8
3,000 g to 6 mo	3.5-4	8
PEDIATRIC
18 mo	4	8
3 yr	4.5	8
5 yr	5	10
6 yr	5.5	10
8 yr	6	10
ADULT
16 yr	7	10
Normal-size woman	7.5-8	12
Normal-size man	8-8.5	14
Large adult	9-10	16

(TT), the suction catheter’s one half the inner diameter of the ET or TT.

* For suctioning of endotracheal tubes (ET) and tracheostomy tubes

a. Calculations related to catheter size (math review)

The following formula can be used to calculate the OD of any suction catheter to determine the endotracheal or tracheostomy tube size with which the suction catheter may be used:

Suction catheter size (Fr) × 0.33=OD(mm) of suction catheter

EXAMPLE 2

Calculate the largest suction catheter that should be used with a size 8 (ID) endotracheal tube:

Therefore, a 12 Fr suction catheter could be used with an 8-mm ID endotracheal (or tracheostomy) tube (see Figure 13-3).

Knowing the ID of a suction catheter is helpful because it relates to the maximum particle size that can pass through it. The following formula can be used to interconvert from French OD to millimeters ID:

EXAMPLE 3

What is the ID in millimeters of a 12 Fr suction catheter?

mm = 2.5(see Figure 13-3)

Therefore, a 12 Fr suction catheter (with a 4-mm OD) can be used to suction particles up to 2.5 mm in diameter.

b. Get the necessary equipment for the procedure

The term open-airway suctioning is used here to refer to a suctioning procedure on a patient who is spontaneously breathing room air after being disconnected from the source of supplemental oxygen. For example, in a patient with a normal upper airway, the oxygen mask is removed for nasotracheal suctioning. Also, in a patient with an endotracheal or a tracheostomy tube, the aerosol T-piece (Briggs adapter) or ventilator circuit is removed to allow suctioning.

These types of catheters have been in use for many years. The two basic types are shown in Figure 13-4. Closing the thumb control, as shown in Figure 13-5, allows the vacuum to be selectively applied to the secretions when desired. The tips of the catheters can vary greatly. A considerable amount of effort has been spent trying to develop a catheter tip that most effectively removes secretions without damaging the tracheal mucosa. Figure 13-6 shows some of the catheter tips that have been developed to minimize mucosal damage. Note that all feature at least one opening in the catheter that is back from the opening at the tip. Compare this with the single end opening found on the oral suction catheter (see Figure 13-2). The side openings are designed to prevent the vacuum from being applied to the tip when it makes contact with the mucosa.

Figure 13-4 Features of two types of suction catheters with angle-cut tips and side holes. A, This catheter has its own thumb control valve. B, This catheter must have a thumb control valve constructed from a Y-connector.

Figure 13-5 Close-up of a thumb control valve showing how room air is drawn into vacuum tubing when the valve is left open. Closing the valve creates a vacuum at the catheter tip, allowing secretions to be suctioned.

Figure 13-6 Close-ups of the ends of three suction catheters. A, Bevel-cut tip with two offset side holes. B, Ring tip with several side holes around it. C, Coudé (curved-tip) catheter; the curve may help guide the catheter into either the left or right mainstem bronchus.

(From Rarey KP, Youtsey JW: Respiratory patient care, Englewood Cliffs, NJ, 1981, Prentice-Hall.)

Notice in Figures 13-4 and 13-6 that most catheters are straight throughout their length. All of these catheters tend to enter the right mainstem bronchus during deep suctioning. This is because the right mainstem bronchus’s angle off of the trachea is less acute than that of the left mainstem bronchus. Therefore, it is difficult, if not impossible, to use any of these catheters to suction the left mainstem bronchus. The Coudé catheter has an angled tip to make it easier to guide into the left (or right) mainstem bronchus (see Figure 13-6, C). When these catheters are used, the direction of the thumb control valve can help determine the angle of the bent tip.

Use of these traditional types of catheters during open-airway suctioning always results in some level of hypoxemia. The newer, insufflating suction catheter is designed to provide alternatively oxygen through the catheter or vacuum for suctioning. The thumb control end of the catheter is modified with two male-type tubing connectors and a way to switch the lumen of the catheter between them. The thumb control is set to direct the oxygen through the catheter and into the patient as the catheter is advanced. After the catheter has been deeply placed into the trachea for suctioning, the thumb control is switched from delivering oxygen to applying suction.

c. Get the necessary equipment for the procedure

The term closed-airway suctioning is used here to refer to a suctioning procedure in which the patient remains connected to the original source of oxygen. This may be done through a special aerosol T-piece or, more commonly, for an intubated patient receiving mechanical ventilation with positive end-expiratory pressure (PEEP). In addition, closed-airway suctioning may reduce the risk of ventilator-associated pneumonia (VAP). This suctioning method is preferred in patients who are likely to become hypoxic when disconnected from their oxygen source.

In closed-airway suctioning systems, a flexible, clear plastic sheath covers the catheter to maintain its sterility (Figure 13-7). The practitioner does not need gloves. When used for patients who need frequent suctioning, self-contained systems have a financial advantage over the traditional catheter and gloves suctioning method, because they can be reused. Closed-system suction catheters come with either the traditional straight tip or the Coudé tip for selective bronchial suctioning.

Figure 13-7 Self-contained catheter and sheath suctioning system for closed-airway suctioning (based on the Kimberly-Clark/Ballard Trach Care closed endotracheal suction device).

Another device used to create a sealed system for endotracheal tube suctioning consists of an elbow adapter that has an inner plastic sleeve or diaphragm. As the traditional catheter is inserted into the opening on the elbow adapter, the sleeve or diaphragm conforms to the catheter so that no air leakage occurs (Figure 13-8). This ensures that the ventilator-delivered volumes and pressures are not lost through a leak.

Figure 13-8 Features and placement of a special elbow adapter, which allows closed-airway suctioning without loss of tidal volume or pressure during mechanical ventilation.

d. Put the equipment together andmake sure that it works properly

Figure 13-4 shows the attachment of an open-airway suction catheter to the vacuum tubing, and Figure 13-7 shows the attachment of a closed-airway suction catheter to the vacuum tubing. The other end of the vacuum tubing is attached to the vacuum regulator system.

With open-airway suctioning, only a hand covered by a sterile glove can be allowed to touch the area of the catheter that enters the patient’s trachea. The practitioner’s other hand also should be gloved. A clean glove is acceptable for that hand, because it does not touch the part of the catheter that will enter the patient’s trachea.

While holding the body of the catheter, the thumb control valve, and the vacuum connector with the sterile-gloved hand and the vacuum tubing with the cleangloved hand, slip the vacuum tubing over the catheter’s vacuum connector. The seal should be tight so that no vacuum leak occurs. From now on, only the sterile-gloved hand may touch the part of the catheter that makes contact with the patient. The clean-gloved hand may touch only the thumb control valve and vacuum tubing. If the catheter is contaminated, it must be discarded.

The catheter can be tested for patency and vacuum at the tip by the three methods described earlier in the discussion on oropharyngeal suction devices. Note that only a sterile glove may be touched against the tip of the suction catheter to check for a vacuum.

The practitioner does not need gloves when a selfcontained catheter is used for closed-airway suctioning, because the sheath covers the catheter to prevent contamination.

Exam Hint 13-2 (ELE, WRE)

Remember that endotracheal suctioning is a sterile procedure. Gloves or a catheter that has become contaminated must be replaced with sterile equipment.

e. Troubleshoot any problems with the equipment

The three common causes of an equipment failure and how to troubleshoot them are described in the earlier discussion on oropharyngeal suction devices. Remember to withdraw the closed-airway suctioning catheter completely from the endotracheal tube into the sheath, or it will partially obstruct the tube.

3. Specimen collectors

a. Get the necessary equipment

A variety of specimen collectors (commonly called Lukens traps) are available. They are packaged as sterile so that no contamination of the sputum sample occurs with nonpatient organisms. Figures 13-9 through 13-12 show the key features and functions of several sputum sample collectors. The sputum sample is obtained through a suction catheter or bronchoscope.

Figure 13-9 Features of a collection system for sputum specimens that includes a thumb control valve.

Figure 13-10 Features of a collection system for sputum specimens that does not have a thumb control valve.

Figure 13-11 Features of a collection system for sputum specimens that has a thumb control valve built into catheter.

Figure 13-12 Features of the DeLee collection system for sputum specimens, showing the mouthpiece through which the practitioner can apply suction.

The specimen jar has volume markings. It screws into either a special lid used to suction the specimen or a regular lid. The regular lid is used for shipment to the laboratory. The special lids used in the systems featured in Figures 13-9 and 13-10 must be connected to a sterile catheter. Figure 13-11 shows a system with its own catheter. The vacuum source is provided to these specimen collectors by a length of vacuum tubing, as in the previously described suction catheter systems. Figure 13-12 shows a DeLee system, which is sometimes used in the delivery room. The physician, nurse, or practitioner uses mouth suction to remove secretions from the newborn. In all of these examples, after the sample has been collected, the special lid is unscrewed and replaced with the regular specimen jar lid.

b. Put the equipment together and make sure that it works properly

A properly working specimen collection system provides a vacuum to the tip of the suction catheter when the thumb control valve or mouthpiece is sealed and vacuum is applied. This is tested by dipping the catheter tip into a container of sterile water or saline solution. The liquid is drawn up the catheter and deposited in the specimen jar. (The water can be discarded from the jar.)

c. Troubleshoot any problems with the equipment

Failure to have a vacuum at the tip of the suction catheter may be caused by any of the previously mentioned possibilities. They can be checked and corrected by the methods listed earlier. Two causes of an inability to suction secretions are common. One cause is that the jar is not screwed tightly into the special lid, allowing room air to be drawn in. Simply screw the lid in tightly. The second cause is that the secretion channel is plugged. Discard it and replace it with a new specimen collector.

MODULE B

Vacuum regulator systems

1. Manipulate vacuum regulator systems by order or protocol (ELE Code: IIA21) [ELE Difficulty: R, Ap, An]

2. Get the necessary vacuum regulator system: vacuum pump, regulator, and collection bottle

3. Put the equipment together and make sure that it works properly

Vacuum regulators are preassembled by the manufacturer. The two basic types are described here. Components must be added to make them fully functional.

a. Portable vacuum systems

Portable units are designed to be moved with the patient. They may be mounted on a small platform (Figure 13-13) or on a wheeled cart. The portable systems generally include an electrically powered vacuum pump with an ON/OFF switch and a collection bottle. Some units have a control valve for adjusting the level of negative pressure. A negative-pressure gauge is used to determine how much vacuum is being applied. A length of rubber vacuum tubing is used to pass the negative pressure from the pump to the collection bottle. Another length of vacuum tubing is used to pass the vacuum through to the suction catheter. Portable systems are not as powerful as central vacuum systems. They are not very effective at suctioning out large amounts of thick secretions.