A neonate on CPAP via nasal prongs at 5 cmH2O; the high-pressure alarm is sounding. Which of the following sets of conditions could cause this?

• A. 1 and 2 only
• B. 1 and 3 only
• C. 3, 4 and 5 only
• D. 1, 3, 4 and 5 only

Answer: (C)

A high-pressure alarm on CPAP means airway pressure is rising above what the set CPAP level would produce, usually from increased resistance in the airway or circuit, or from reduced compliance in the lungs. In a neonate with nasal CPAP, this can happen when there’s airway obstruction or increased resistance such as secretions or mucus plugging, when the patient coughs or gags which transiently raises intrathoracic pressure, or when the delivery tubing or nasal prongs are kinked, occluded, or not fitting well, all of which make it harder for air to flow and push the pressure up. These scenarios are the ones that elevate the measured pressure and trigger the alarm. By contrast, issues that cause leaks or disconnections tend to lower the pressure or create a low-pressure alarm rather than a high-pressure one. So the best-fitting set includes those conditions that increase resistance in the airway or circuit.