title: Percutaneous needle cricothyroidotomy with repetitive airway obstruction.
abstract: To develop a technique for needle cricothyrotomy that mimics the normal respiratory cycle (using repetitive obstruction of the upper airway and relatively low flow oxygen through small catheters), a controlled trial in three anesthetized dogs was performed. Oxygen from a standard bottle and pressure reducer was delivered through the cricothyroid membrane at 0.36 L/kg/min, which is metabolically equivalent to 0.2 L/kg/min in an adult human. The upper airway was obstructed until the chest rose and then was unobstructed to allow exhalation. The animals were ventilated for 5 minutes to allow equilibration. Arterial PCO2 was measured after 2-minute periods of apnea and 3 minutes of ventilation, each repeated four times. The procedure was repeated in three other dogs at a flow of 0.18 L/kg/min to simulate a 50% air leak. Cricothyroid ventilation at 0.36 L/kg/min lowered the PCO2 from 65 mm Hg to 43 mm Hg, F = 258, P = .004. All PCO2 after 25 minutes were in the normal range. Ventilation at 0.18 L/kg/min stabilized the PCO2 at approximately 1.5 times normal (67 mm Hg versus 79 mm Hg for the preceding apnea, F = 77, P = .013). Flow rates achievable with 18- to 20-gauge catheters and standard oxygen sources are adequate for cricothyroid ventilation when the airway is repetitively obstructed to allow a normal respiratory cycle.
authors.affiliation: University of New Mexico School of Medicine, Department of Emergency Medicine, Albuquerque 87131-5246, USA.
authors.forename: M
authors.initials: M
authors.lastname: Hauswald
authors.forename: G
authors.initials: G
authors.lastname: Ong
authors.forename: E
authors.initials: E
authors.lastname: Yeoh
mesh_terms: D000402:Airway Obstruction; D000818:Animals; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000378:metabolism; D003413:Cricoid Cartilage / Q000601:surgery*; D004285:Dogs; D006611:High-Frequency Jet Ventilation / Q000379:methods*; D010100:Oxygen / Q000378:metabolism; D011677:Punctures / Q000379:methods*; D013961:Thyroid Gland / Q000601:surgery*
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen