Airway, Respiration & Ventilation Flashcards

A 68-year-old male with a history of COPD is being ventilated with a bag-valve mask. Quantitative waveform capnography shows a prolonged Phase II and a 'shark fin' appearance. What is the most likely cause of this finding?

Answer: Bronchospasm

The 'shark fin' waveform on a capnogram, characterized by a sloping and prolonged Phase II (expiratory upstroke) and a less distinct alveolar plateau, is a classic sign of bronchoconstriction or airway obstruction. [1] This shape indicates that alveoli are emptying at different rates due to the obstruction, leading to a slower rise in expired CO2.

You are transporting a 5-year-old child in respiratory distress. Which anatomical difference in a pediatric airway, compared to an adult, is most critical to consider when positioning the patient for basic airway management?

Answer: The occiput is proportionally larger.

In infants and young children, the proportionally larger occiput causes the neck to flex when the child is laid supine. [31] This flexion can obstruct the airway. To achieve a neutral or 'sniffing' position for optimal airway alignment, padding should be placed under the shoulders and torso to elevate the chest. [26, 31]

A paramedic is managing a mechanically ventilated patient following intubation. The high-pressure alarm on the ventilator sounds. After confirming the patient is not biting the tube and there are no kinks in the circuit, which of the following is the most appropriate next step?

Answer: Suction the endotracheal tube.

Common causes of a high peak airway pressure alarm include obstructions. [29] After ruling out external issues like a kinked tube or the patient biting it, an internal obstruction such as a mucus plug is a likely cause. [29] Suctioning the endotracheal tube is the appropriate intervention to clear such a blockage and resolve the high pressure.

Which of the following is a primary indication for performing a needle cricothyrotomy in the prehospital setting?

Answer: A 'can't intubate, can't ventilate' situation with massive maxillofacial trauma.

A cricothyrotomy is an invasive, rescue airway procedure indicated only when all other methods of securing an airway have failed or are impossible. [22] A 'can't intubate, can't ventilate' scenario, such as one caused by massive facial trauma that prevents bag-mask ventilation or intubation, is a primary indication. [8, 22]

You are setting up a ventilator for a 70 kg adult male patient diagnosed with Acute Respiratory Distress Syndrome (ARDS). According to the ARDSNet protocol, what should the initial tidal volume be set to?

Answer: 6 mL/kg

The ARDSNet protocol recommends a lung-protective ventilation strategy that includes low tidal volumes to prevent ventilator-induced lung injury. The standard initial tidal volume is 6 mL/kg of predicted body weight. [10, 14, 21, 24]

A patient in cardiac arrest has been intubated. Continuous waveform capnography shows an abrupt and sustained increase in the end-tidal CO2 (ETCO2) reading from 15 mmHg to 40 mmHg. This finding is most indicative of:

Answer: Return of Spontaneous Circulation (ROSC)

A sudden, sharp, and sustained increase in ETCO2 during CPR is a strong indicator of Return of Spontaneous Circulation (ROSC). [11] The restored circulation transports a large amount of accumulated CO2 from the tissues to the lungs, causing a spike in the ETCO2 reading.