The present disclosure relates to a ventilation system comprising: a ventilator; and a nasal interface in fluid communication with the ventilator, the nasal interface comprising: an outer tube having an inlet, an outlet, and a jet pump throat between the inlet and the outlet, the outer tube being dimensioned to fit at least partially inside a patient's nostril; a nozzle for delivering gas from the ventilator into the inlet of the outer tube; and a breath sensing lumen terminating in a breath sensing port within the outer tube. The disclosure further relates to a nasal interface for delivering ventilation gas to a patient.