When submandibular muscles relax while a person is in a recumbent position, the tongue falls against the posterior pharyngeal wall and may obstruct the pharynx. The oropharyngeal airway (OPA) is designed to create a conduit through the oropharynx and posterior pharynx, keeping the airway open. The OPA is a rigid, comma-shaped device that has either a hollow inner channel or a solid core and hollow side channels (Fig. 17-4). Because the placement of the OPA stimulates the posterior pharynx, its use should be reserved for the unconscious and unresponsive patient with no cough or gag reflex. There are three methods for placing the OPA: (1) invert the device and rotate it into place when it reaches the posterior pharynx, or (2) turn the device 90 degrees and rotate it into place when it reaches the posterior pharynx, or (3) insert it directly by following the curve of the tongue, with or without the help of a tongue depressor. Whichever technique is chosen, care must be taken not to push the tongue into the posterior pharynx, thus causing airway obstruction. If there are problems ventilating the patient after insertion of the OPA, the device should be removed and reinserted. Although studies have not specifically addressed use of the OPA in cardiac arrest, clinical experience shows that it may aid ventilation with a bag-mask device by preventing the tongue from occluding the airway.

The nasopharyngeal airway (NPA) is a soft rubber, Silastic, or plastic hollow tube that is inserted through the nose to the posterior pharynx, creating an opening
between the tongue and posterior pharyngeal wall (Fig. 17-5). NPAs are particularly useful when conditions such as a clenched jaw prevent placement of an OPA. NPAs are less likely than OPAs to stimulate the gag reflex, so are a better choice in patients who are not deeply unconscious. In studies of anesthetized patients, 5% to 30% have bleeding with insertion of an NPA.^18,19 To minimize or prevent bleeding, care must be taken to first lubricate the NPA well, then insert the airway with the beveled edge facing the septum pushing it into the nares while rotating the airway once it has passed the cartilaginous area of the septum, and directing it along the floor of the nose until the flared end of the NPA is against the nasal orifice. If available, a vasoconstricting nasal spray administered before placement may be helpful. Particular care must be taken when placing the NPA in patients with craniofacial injury: inadvertent intracranial placement of an NPA in patients with basilar skull fracture has been described in four case reports.^20,21,22,23

As with all adjunctive equipment, safe use of the NPA requires adequate training, practice, and retraining. Although studies have not specifically addressed the use of the NPA in cardiac arrest, clinical experience shows that it may aid ventilation with a bag-mask device by preventing the tongue from occluding the airway.

Regurgitation is a frequent occurrence in cardiac arrest, and survival to hospital discharge after aspiration of regurgitated materials is very low.²⁴ Suctioning is thus an essential aspect of airway management. Either a portable or installed suction device should be immediately available for resuscitation emergencies. An installed suction unit should be powerful enough to provide an airflow of >40 L/min at the end of the delivery tube and a vacuum of >300 mm Hg when the tube is clamped. The amount of suction should be adjustable to allow for use in children and intubated patients.

Portable units should provide vacuum pressure and flow that is adequate for pharyngeal suction. The suction device should be fitted with large-bore, nonkinking suction tubing and semirigid pharyngeal tips of sufficient size to suction thick fluids and large particulate matter. Also, suction units must be checked regularly and maintained. When 51 paramedics from nine paramedic units were anonymously surveyed, 26 paramedics (51%) reported difficulties with the portable suction equipment. The difficulty most commonly cited (21 times) was clogging of the tubing as a result of thick emesis. Poor suction power and battery problems were cited 13 times. As a result of frequent problems with portable suction units, some emergency medical services (EMS) systems may choose to carry both a battery-operated device and a manual hand-operated suction pump.²⁵

Both soft flexible and rigid suctioning catheters are available. Rigid catheters (e.g., Yankauer) are used to suction the oropharynx. These are better for suctioning thick secretions and particulate matter (Fig. 17-6). Soft, flexible catheters may be used in the mouth or nose. They can also be used for deep suctioning with an endotra-cheal (ET) tube. Soft, flexible catheters come in sterile wrappers.

Several methods can be used to suction the upper airway and trachea. Central to each of these is the prevention both of hypoxia during the procedure and stimulation of reflexes leading to bradycardia and hypotension. Care must
be taken to prevent damage to the airway structures. During the procedure, the patient’s heart rate, pulse, oxygen saturation, and clinical appearance during suctioning should be monitored. If bradycardia develops, oxygen saturation drops, or the patient’s clinical appearance deteriorates, suctioning must be interrupted at once. High-flow oxygen is then administered until the heart rate returns to normal and the patient’s clinical condition improves. Ventilation is assisted as needed.

One method for suctioning the oropharynx and trachea through an endotracheal tube is given in Tables 17-1 and 17-2.

For many years, mouth-to-mouth ventilation has been taught as the basic rescue ventilation technique. Mouth-to-barrier-device has now superseded mouth-to-mouth as the basic ventilation technique recommended for training and for resuscitation, because the interposition of a protective barrier between rescuer and patient addresses a concern that rescuers may have about disease transmission. Although the risk of contagion is very low—there are only 15 reported cases of possible disease transmission during CPR and none during CPR training—surveys of both health care providers and the lay public have repeatedly cited the concern of contagion as a factor affecting the respondent’s expressed willingness to perform mouth-to-mouth ventilation.^{26,27,28,29,30,31,32,33,34} While the interposition of a barrier device is likely to be more aesthetically pleasing to potential rescuers and will perhaps reduce their fears of contagion, whether rescuers actually undertake CPR more often when the device is available is unknown. Clearly, though, a barrier device can increase the likelihood of CPR performance only if health care providers and other potential rescuers carry such a device with them at all times.

The three types of barrier devices are face shields, tubes, and masks (Fig. 17-7). The devices are typically plastic, they may be disposable or reusable, and they often incorporate a unidirectional valve that will direct the victim’s expired air away from the rescuer. In addition, a one-way valve is available that fits to the inlet of a regular face mask,
so that the mask may be used for mouth-to-mask or bag-mask ventilation. Each of the devices has its own performance characteristics, and effectiveness in protecting against infection transmission varies from device to device. Drawbacks associated with some devices include the creation of inspiratory or expiratory resistance and valve leakage. One study that tested a variety of barrier devices found that few of them had low inspiratory and expiratory resistances and that some of the one-way valves failed.³⁵ In another study, where cultures were performed after mock CPR, none of the masks with one-way valves were culture-positive but one of three face shields that incorporated a one-way valve was culture positive and five of five face shields that did not have a one-way valve were contaminated with the victim’s oral aerobic flora.³⁶ It has not been proven that a barrier device will prevent disease transmission in real-world use, and, given the very low rate of disease transmission that has been reported, it is unlikely that effectiveness will be established.

Mouth-to-barrier ventilation, like mouth-to-mouth ventilation, relies on the rescuer’s expired air to ventilate the victim. Most rescuers will have the vital capacity necessary to provide the 5 to 6 L/min of air required for lung inflation but will be able to provide only 17% oxygen, which is the approximate concentration of oxygen in expired air. If an oxygen source is available, the rescuer should wear a nasal cannula or should breathe from the oxygen source between rescue breaths. As soon as possible, the rescuer should switch to a barrier device that has an oxygen inlet, a bag-mask device with attached oxygen, or some other airway adjunct that will allow for the administration supplementary oxygen.

Both tube and face-shield devices fit adults of all sizes, but any given mask fits people only within a particular size range, so the rescuer must have masks of different sizes available. If a mask is too big or too small for the given patient, an air leak will occur, which may reduce the effectiveness of ventilation. A leak can often be tolerated, however, since a full breath often provides more air than is required. The mouth-to-mask technique is easier than bag-mask ventilation, since the rescuer is able to use two hands to correctly elevate the mandible, position the head, and seal the mask to the face. Studies on manikins have found that mouth-to-mask ventilation is capable of delivering significantly larger tidal volumes than bag-mask ventilation, and a similar study on patients after induction of anesthesia endorsed mouth-to-mask ventilation for its ease of use by inexperienced operators.^37,38,39,40 No matter which barrier device is used, adequate training is important to ensure effective ventilation.⁴¹

Pocket face masks can be used effectively by a provider who is trained in their use and effectively maintains an open airway. Most have side ports for the administration of oxygen. (Fig. 17-8).

Bag-mask ventilation (BMV) is a fundamental skill of emergency airway management that has been taught to health care providers as part of both basic and advanced airway management for more than 40 years. Effective BMV is difficult to perform: in several studies, both inexperienced and experienced providers delivered inadequate tidal volumes
when tested on manikins.^{42,43,44,45,46,47,48} When tested on anesthetized subjects, where the face is more malleable and the lungs are more compliant than in a manikin, ventilation with a bag-mask is still frequently inadequate: in a study of BMV use by 30 inexperienced nurses, the tidal volume averaged only 239 mL.⁴⁹ In another study, 10 nurses were able to adequately ventilate 100 patients only 43% of the time.⁵⁰ Ventilation is unlikely to be performed any better under resuscitation conditions than it is under the controlled conditions of a study.

In order to provide effective ventilation with a bag-mask, the head, neck, and mandible must be positioned so that the tongue does not obstruct the airway and a correctly sized mask must then be chosen so that a tight seal of the mask to the face can be achieved (Fig. 17-9). Next, the bag must be squeezed in a deliberate, consistent manner over 1 second so as to avoid high inspiratory pressures and thus prevent gastric inflation. Each of these steps may pose difficulty. The head must be tilted back and maintained in neutral or slightly extended position while pulling the jaw forward and pressing the mask down, all with one hand, while the second hand must hold and squeeze the bag (Fig. 17-9A, Table 17-3A). If the patient is edentulous or bearded, the mask seal will be more difficult to achieve. Maintaining a seal in the back of a moving ambulance can be especially challenging.

To improve the mask seal and ensure that the hand squeezing the bag is large enough to hold and compress a sufficient volume of air from the bag, an effective strategy
is for one rescuer to open the airway and seal the mask using both hands, while a second rescuer uses both hands to squeeze the bag. Two rescuers may provide more effective ventilation than one rescuer. When two rescuers use the bag-mask system, one rescuer opens the airway with a head tilt and jaw lift and holds the mask to the face while the other rescuer squeezes the bag (Fig. 17-9B, Table 17-3B). Squeezing the bag requires minimal explanation and can typically be performed even by untrained assistants.

Techniques for holding the mask are the same as those for the mouth-to-mask devices described above.^51,52,53,54,

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