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HLT-RESP80-05 · Lesson 3 · 37.5 clock hours · lab

Basic Airway Adjuncts: OPA, NPA, and Bag-Mask Ventilation

Objective. Students will correctly size, insert, and remove an oropharyngeal airway (OPA) and a nasopharyngeal airway (NPA) on adult and pediatric manikins, and will deliver effective bag-mask ventilation with visible chest rise.

⚠ Pending professional review

This lesson, its worked examples and its practice questions has not yet been verified by a licensed clinician in the field or by a certification or approval body. It is a study draft and may contain errors. Do not use it to make decisions about any patient or medication. Always follow your instructor, your supervising professional, and current official references and regulations.

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Why Basic Airway Adjuncts Matter

Maintaining a patent airway is the single most critical step in any resuscitation or emergency care situation. When a patient loses consciousness or muscle tone, the tongue and soft palate fall against the posterior pharynx and obstruct airflow. Two simple mechanical devices — the oropharyngeal airway (OPA) and the nasopharyngeal airway (NPA) — keep that passage open so you can ventilate effectively. Knowing how to select the right size, insert the device correctly, and then deliver bag-mask ventilation (BMV) with adequate tidal volume is a core competency for every respiratory therapist and is tested on both the NBRC credentialing exams and your state license application.

Oropharyngeal Airway (OPA)

The OPA is a curved, rigid plastic device that sits between the tongue and the posterior pharynx. It is intended only for unconscious patients who have no gag reflex. Inserting an OPA in a patient who is awake or semi-conscious risks stimulating the gag reflex and causing vomiting and aspiration — a life-threatening complication.

Sizing: Hold the OPA against the patient's face. The correct size spans from the corner of the mouth to the earlobe (or, alternatively, from the center of the mouth to the angle of the jaw). If the device is too short, it will push the tongue back and worsen the obstruction. If it is too long, it may stimulate the larynx or epiglottis and cause laryngospasm.

Adult insertion technique: Open the mouth using a cross-finger or tongue-jaw lift technique. Insert the OPA with the curve pointing toward the roof of the mouth (inverted, tip pointing toward the hard palate), then rotate 180° as it passes the soft palate so the curve follows the natural contour of the tongue. In pediatric patients, do not use the rotation method — the soft palate is more easily damaged. Instead, use a tongue depressor to displace the tongue forward and insert the OPA with the curve already directed downward (toward the floor of the mouth).

Confirm position: The flange should rest at the lips, the tip should be in the hypopharynx, and the tongue should be displaced forward. Bag-mask ventilation should produce visible bilateral chest rise without significant air leak around the mouth.

Nasopharyngeal Airway (NPA)

The NPA is a soft, flexible tube inserted through a nostril and advanced along the floor of the nasal passage to sit just above the epiglottis in the nasopharynx. Unlike the OPA, the NPA is tolerated by patients who are semiconscious or have an intact gag reflex. It is the preferred adjunct when the mouth cannot be opened, there is oral trauma, or trismus is present.

Contraindications: Exercise caution or avoid NPA use when there is known or suspected basilar skull fracture (clinical signs include Battle's sign, raccoon eyes, or cerebrospinal fluid from the nose or ears), significant nasal trauma, or coagulopathy with high bleeding risk. Always follow your institution's clinical protocol and the supervising physician's order.

Sizing: Choose a size based on inner diameter (ID) and length. A common field estimate is to match the outer diameter to the patient's nostril opening and the length to the distance from the tip of the nose to the earlobe. Sizes are typically expressed in millimeters of internal diameter.

Insertion technique: Apply a generous amount of water-based lubricant to the external surface of the NPA. Insert the bevel (angled tip) toward the nasal septum. Advance straight back along the floor of the nasal cavity, not upward toward the top of the skull. If resistance is met, do not force the device — try the other nostril. The flange should rest at the naris when fully seated. Never use oil-based lubricants, as these can damage nasal mucosa and are harmful if aspirated.

Bag-Mask Ventilation (BMV)

Bag-mask ventilation delivers positive-pressure breaths when a patient cannot breathe adequately on their own. The bag-valve-mask (BVM) resuscitator consists of a self-inflating bag, a one-way valve, and a mask. An oxygen reservoir on the bag allows delivery of high-concentration oxygen.

Mask seal — the E-C clamp: Place the mask over the nose and mouth with the narrow end over the nasal bridge. Form a "C" with the thumb and index finger pressing the mask down, and hook the remaining three fingers (forming an "E") under the mandible to perform a jaw thrust, lifting the face into the mask. This technique maintains airway alignment while sealing the mask.

Two-person BMV is superior to one-person BMV and is the standard of care in non-intubated patients whenever a second provider is available. One person holds the mask with both hands using a bilateral E-C clamp or thenar eminence technique; the second person squeezes the bag. This dramatically improves mask seal and tidal volume delivery.

Target tidal volumes: For adults, deliver enough volume to produce visible chest rise — approximately 500–600 mL or roughly 6–7 mL/kg of ideal body weight. Over-ventilation causes gastric insufflation, regurgitation, and can impede venous return. For pediatric patients, use the appropriately sized pediatric BVM and use the same visible chest rise guideline, adjusting squeeze pressure accordingly. Ventilation rate during CPR follows current resuscitation guidelines; in non-arrest patients with a pulse, ventilate at a rate appropriate for the patient's age and clinical condition.

Common errors to correct: poor mask seal (most common cause of inadequate tidal volume), head position not maintained in sniffing position, squeezing the bag too forcefully (barotrauma risk), and ventilating too rapidly (auto-PEEP and gastric distension risk).

Safety Summary

Key terms8

Oropharyngeal airway (OPA)A rigid curved plastic device inserted through the mouth to hold the tongue away from the posterior pharynx; used only in unconscious patients without a gag reflex.
Nasopharyngeal airway (NPA)A soft flexible tube inserted through a nostril and advanced to the nasopharynx to maintain airway patency; tolerated by semiconscious patients and those with an intact gag reflex.
Bag-valve-mask (BVM) resuscitatorA self-inflating bag connected to a one-way valve and mask used to deliver positive-pressure ventilation; includes an oxygen reservoir for high-concentration oxygen delivery.
E-C clamp techniqueA single-provider mask-holding method in which the thumb and index finger form a 'C' to press the mask onto the face while the other three fingers form an 'E' under the mandible to perform a jaw thrust.
Jaw thrustA manual airway maneuver that displaces the mandible anteriorly to open the airway without extending the neck; preferred when cervical spine injury is suspected.
Tidal volumeThe volume of air delivered in a single breath; during bag-mask ventilation of an adult, targeting visible chest rise corresponds to approximately 500–600 mL.
Gastric insufflationUnintended delivery of air into the stomach during bag-mask ventilation, typically caused by excessive tidal volumes or ventilation pressure; increases risk of regurgitation and aspiration.
Basilar skull fractureA fracture of the base of the skull that is a relative contraindication to NPA insertion because of the risk of inadvertent intracranial passage of the airway device.

Worked examples4

1. You are sizing an OPA for an adult manikin. Using the corner-of-mouth-to-earlobe technique, you measure the distance on the manikin and find that an 80 mm, 90 mm, and 100 mm OPA are available. The measured distance is approximately 90 mm. Which do you select, and why?
  1. Step 1: Identify the landmark — corner of mouth to earlobe — and note the measured distance of approximately 90 mm.
  2. Step 2: Compare available sizes: 80 mm would be too short and risk pushing the tongue backward, worsening obstruction. 100 mm would be too long and could contact the larynx or epiglottis, risking laryngospasm.
  3. Step 3: Select the 90 mm OPA as the best match to the measured landmark distance.
Answer: Select the 90 mm OPA. It matches the corner-of-mouth-to-earlobe distance, ensuring the tip reaches the hypopharynx to displace the tongue without extending so far as to stimulate the larynx.
2. During two-person bag-mask ventilation on an adult manikin, your instructor tells you the chest is not rising. You are the bag operator; your partner is holding the mask. List the corrective steps in priority order.
  1. Step 1: Ask your partner to recheck mask seal — the most common cause of failed chest rise is mask leak. Ensure the mask edges conform to the face, particularly at the nasal bridge and chin.
  2. Step 2: Confirm head position is in the sniffing position (slight neck extension for adults) to align oral, pharyngeal, and tracheal axes.
  3. Step 3: Ask your partner to improve jaw thrust — lifting the mandible anteriorly opens the airway and pulls soft tissue away from the posterior pharynx.
  4. Step 4: If an OPA or NPA is in place, verify it is seated at the correct depth and has not been displaced.
  5. Step 5: Once seal and position are corrected, squeeze the bag steadily over approximately one second and observe for visible bilateral chest rise.
Answer: Correct in order: mask seal → head position → jaw thrust → adjunct position → re-attempt ventilation. Visible bilateral chest rise confirms effective correction.
3. You need to estimate an appropriate NPA size for an adult patient. The available sizes are 6 mm, 7 mm, and 8 mm internal diameter. You note that the patient's nostril comfortably accommodates a diameter that appears to match the 7 mm device, and the tip-of-nose-to-earlobe distance is approximately 13 cm. Which NPA do you select?
  1. Step 1: Use the nostril fit guideline — the outer diameter of the NPA should fit snugly but without blanching the nasal ala. The patient's nostril matches the 7 mm ID device.
  2. Step 2: Confirm length is adequate — a 7 mm NPA typically has a corresponding length that spans approximately the nose-to-earlobe distance for an average adult; verify the selected device length is appropriate for the measured 13 cm.
  3. Step 3: Rule out the 6 mm (likely too narrow — reduced airflow and easier to obstruct) and the 8 mm (may be too wide for this patient's nostril, risking mucosal trauma and bleeding).
Answer: Select the 7 mm ID NPA. It fits the nostril without excessive pressure, and its length is appropriate for the nose-to-earlobe distance, ensuring proper nasopharyngeal placement.
4. An adult patient weighing 70 kg (ideal body weight) requires bag-mask ventilation. Using a target of 6–7 mL/kg of ideal body weight, calculate the acceptable tidal volume range.
  1. Step 1: Multiply the lower target by ideal body weight: 6 mL/kg × 70 kg = 420 mL.
  2. Step 2: Multiply the upper target by ideal body weight: 7 mL/kg × 70 kg = 490 mL.
  3. Step 3: Note that most clinical guidelines for BMV in adults simplify this to approximately 500–600 mL and instruct providers to use visible chest rise as the primary endpoint, which aligns closely with these calculated values.
Answer: The calculated acceptable tidal volume range is approximately 420–490 mL. In practice, target visible chest rise; this volume range supports adequate ventilation while minimizing gastric insufflation and barotrauma risk.
In class: Practice OPA sizing using the corner-of-mouth-to-earlobe landmark technique on at least three manikin sizes, then insert and confirm position without causing simulated trauma. · Size and lubricate an NPA for an adult manikin, insert along the floor of the nasal passage, and confirm patency; then repeat for a pediatric manikin using appropriate sizing. · Perform two-person bag-mask ventilation on a manikin with an instructor introducing simulated obstructions; student must correct mask seal, adjust head position, and maintain tidal volumes within the acceptable range for the patient size.
Materials: Adult and pediatric airway manikins, OPAs in assorted sizes, NPAs in assorted sizes, water-based lubricant, BVM resuscitators (adult and pediatric), disposable gloves, face shields, cleaning supplies
Check: Instructor-observed skills checklist: student selects correct size, inserts device without critical error, and achieves visible bilateral chest rise on bag-mask ventilation on two consecutive attempts; pass = zero critical errors.

Practice check8

Answer each question, then check it. Nothing is recorded; this is your own practice.

Airway Management / Patient Care
1. A patient is semiconscious following a seizure and has an intact gag reflex but cannot maintain airway patency. Which airway adjunct is most appropriate?
Airway Management / Equipment
2. When sizing an OPA for an adult patient, which anatomical landmark technique is standard?
Airway Management / Pediatric Care
3. During OPA insertion in a pediatric patient, the respiratory therapist should:
Airway Management / Ventilation
4. A respiratory therapist is performing one-person bag-mask ventilation on an unconscious adult and notes no chest rise. After repositioning the head, the chest still does not rise. What is the most effective next intervention?
Airway Management / Safety
5. Which of the following is a contraindication or reason for extreme caution before inserting a nasopharyngeal airway?
Airway Management / Safety
6. What type of lubricant must be used when inserting a nasopharyngeal airway, and why?
Ventilation / Patient Care
7. During adult bag-mask ventilation, which of the following tidal volume targets and primary clinical endpoint are correct?
Airway Management / Safety
8. An OPA that is too large for the patient is most likely to cause which complication?
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