PHTLS - Prehospital Trauma Life Support Prehospital Trauma Life Support Airway and Ventilation 1 — Questions and Answers
Question 1: What is the recommended ventilation rate when providing BVM ventilation to an apneic adult trauma patient?
- One breath every 5–6 seconds (10–12 breaths/min) (Correct answer)
- One breath every 3 seconds (20 breaths/min)
- One breath every 8–10 seconds (6–8 breaths/min)
- Two rapid breaths followed by a 30-second pause
Correct answer: One breath every 5–6 seconds (10–12 breaths/min)
PHTLS guidelines recommend 10–12 breaths per minute (one breath every 5–6 seconds) for apneic adult trauma patients. This rate maintains adequate oxygenation and CO2 clearance without the risks of hyperventilation, such as increased intracranial pressure or impaired venous return.
Question 2: A restrained driver involved in a high-speed collision becomes increasingly agitated and then unresponsive. Assessment reveals absent breath sounds on the left, distended neck veins, and hypotension. What is the priority prehospital intervention?
- Needle decompression of the affected side (Correct answer)
- Immediate endotracheal intubation
- Spinal immobilization and rapid transport only
- Application of a thoracic pressure dressing
Correct answer: Needle decompression of the affected side
The triad of absent unilateral breath sounds, distended neck veins, and hypotension indicates tension pneumothorax. Needle decompression on the affected side is the immediate life-saving intervention to relieve intrathoracic pressure before it causes cardiac arrest.
Question 3: A nasopharyngeal airway (NPA) is preferred over an oropharyngeal airway (OPA) in which of the following trauma scenarios?
- A semiconscious patient with an active gag reflex (Correct answer)
- A deeply unresponsive patient with no gag reflex
- A patient with suspected basilar skull fracture
- A patient with active epistaxis and facial trauma
Correct answer: A semiconscious patient with an active gag reflex
The NPA is tolerated by patients with an intact or active gag reflex who are semiconscious, because it bypasses the oropharynx where the gag reflex is triggered. The OPA is reserved for deeply unresponsive patients without a gag reflex to avoid inducing vomiting.
Question 4: What is the most clinically significant limitation of pulse oximetry (SpO2) monitoring in a hemorrhagic trauma patient?
- It may display falsely normal readings in the presence of poor peripheral perfusion or carbon monoxide poisoning (Correct answer)
- It cannot be applied to fingers, only earlobes
- It directly measures arterial oxygen partial pressure (PaO2)
- It requires a minimum blood pressure of 80 mmHg to function
Correct answer: It may display falsely normal readings in the presence of poor peripheral perfusion or carbon monoxide poisoning
In hemorrhagic shock, peripheral vasoconstriction reduces signal quality and can cause inaccurate readings. Additionally, carbon monoxide binds hemoglobin similarly to oxygen, causing pulse oximeters to display falsely high SpO2 values. Clinicians must correlate oximetry with the overall clinical picture.
Question 5: In the prehospital setting, when is a surgical airway (cricothyrotomy) indicated for a trauma patient?
- After failed endotracheal intubation attempts when oxygenation cannot be maintained by BVM alone (Correct answer)
- As the first-line airway for any unconscious trauma patient
- When SpO2 falls below 94% despite supplemental oxygen
- When a suspected cervical spine injury prevents head-tilt maneuvers
Correct answer: After failed endotracheal intubation attempts when oxygenation cannot be maintained by BVM alone
Cricothyrotomy is a rescue technique for the 'can't intubate, can't oxygenate' scenario. It is only performed after less invasive airway methods have failed, because it is an invasive procedure with significant risks and is not a first-line intervention.
Question 6: What is the correct tidal volume target when ventilating an adult trauma patient with a bag-valve-mask device?
- Sufficient to produce visible chest rise, approximately 500–600 mL (Correct answer)
- Maximum volume the bag can deliver with each compression
- A fixed volume of 1,000 mL regardless of patient size
- Determined solely by age and body weight formulas
Correct answer: Sufficient to produce visible chest rise, approximately 500–600 mL
PHTLS recommends delivering just enough volume to produce visible chest rise, roughly 500–600 mL for an average adult. Excessive tidal volumes cause gastric insufflation, regurgitation risk, and increased intrathoracic pressure, which can compromise venous return and cardiac output in trauma patients.
PHTLS - Prehospital Trauma Life Support Prehospital Trauma Life Support Airway and Ventilation 1
What is the recommended ventilation rate when providing BVM ventilation to an apneic adult trauma patient?