injuries poisoning
Ear and Sinus Barotrauma
Introduction
Barotrauma is tissue injury caused by a pressure-related change in body compartment gas volume. It can affect the ear (causing ear pain, hearing loss, and/or vestibular symptoms) or the sinuses (causing pain and congestion). Diagnosis sometimes requires audiometry and vestibular testing. Treatment, when required, may involve decongestants, analgesics, and sometimes oral corticosteroids or surgical repair of serious inner or middle ear or sinus injuries. (See also Overview of Diving Injuries and Diving can affect the external, middle, and inner ear. Typically, divers experience ear fullness and pain during descent; if pressure is not quickly equilibrated, middle ear hemorrhage or tympanic membrane rupture may occur. Inflow of cold water to the middle ear may result in vertigo, nausea, and disorientation while submerged. On examination of the ear canal, the tympanic membrane may show congestion, hemotympanum, perforation, or lack of mobility during air insufflation with a pneumatic otoscope; conductive hearing loss is usually present. When pressure within the middle ear remains elevated during or after ascent from a dive, the facial nerve can be compressed (facial baroparesis), resulting in ipsilateral upper and lower facial paresis. Weakness of both upper and lower face distinguishes facial baroparesis from stroke or arterial gas embolism ( General references ). occurs due to rupture of the labyrinthine window (round or oval window) or tears of the Reissner, basilar, or tectorial membranes. Symptoms, which include tinnitus, hearing loss, dizziness, disequilibrium, vertigo, nystagmus, ataxia, nausea, and vomiting, often worsen with activity and loud noise, and improve with rest. Symptoms usually start during descent when there is difficulty equalizing middle ear pressure, but can occur during ascent, possibly due to air expansion within the cochlea or vestibular apparatus. Symptoms can also occur days after a dive, often provoked by lifting or straining ( General references ). most often affects the frontal sinuses, followed by the ethmoid and maxillary sinuses ( General references ). Divers experience mild pressure to severe pain, with a feeling of congestion in the involved sinus compartments during ascent or descent and sometimes epistaxis. Pain can be severe, sometimes accompanied by facial tenderness on palpation. Maxillary sinus overpressurization can compress the maxillary branch of the trigeminal nerve, causing hyperesthesia over the cheek. Overpressurization in the sphenoid sinus occasionally compresses the optic nerve, causing decreased vision or blindness ( Rarely, the sinus may rupture and cause pneumocephalus with facial or oral pain, nausea, vertigo, or headache. Rupture of a maxillary sinus can cause retro-orbital air with diplopia due to oculomotor dysfunction. Compression of the trigeminal nerve in the maxillary sinus can cause facial paresthesias. Physical examination may detect tenderness in the sinuses or nasal hemorrhage. Barotrauma can also occur due to the reduction in ambient pressure during ascent to altitude. 