An endobronchial tube is provided that includes a medical tube comprising an endotracheal portion and a bronchial portion having a common single lumen extending between a proximal end and a distal end of the tube, a first endotracheal inflatable cuff for sealing against a trachea of a patient, a second endotracheal inflatable cuff positioned distal to the first endotracheal inflatable cuff for sealing against the trachea of the patient; a bronchial inflatable cuff positioned near a distal end of the medical tube after the first endotracheal inflatable cuff and the second endotracheal inflatable cuff, for sealing the left main stem bronchi of the patient, an intraluminal balloon blocker positioned along an inner surface of the bronchial portion for sealing the common single lumen at the distal end of the bronchial portion, and an aperture positioned between the endotracheal portion and the bronchial portion.

Disclosed embodiments include apparatuses, systems, and methods for assessing collateral ventilation. An illustrative embodiment includes an occlusion device insertable into a bronchial passageway to selectively seal the bronchial passageway to occlude a lobe of a lung. A flow lumen sealably extends through the occlusion device to a distal end and has a proximal end receptive of a positive pressure flow. A check valve is coupleable with the flow lumen to permit the positive pressure flow to pass to the distal end of the flow lumen and prevent a backflow of pressure from the flow lumen. A flow meter is couplable with the flow lumen to measure the positive pressure flow through the flow lumen. The occlusion device is insertable into the passageway to the isolated lobe. Measurements of the flow meter of the positive pressure flow into the occluded lobe are monitorable to assess collateral ventilation from the occluded lobe.