Airway management during spaceflight: A comparison of four airway devices in simulated microgravity

Background: The authors compared airway management in normogravity and simulated microgravity with and without restraints for laryngoscope-guided tracheal intubation, the cuffed oropharyngeal airway, the standard laryngeal mask airway, and the intubating laryngeal mask airway. Methods: Four trained anesthesiologist-divers participated in the study. Simulated microgravity during spaceflight was obtained using a submerged, full-scale model of the International Space Station Life Support Module and neutrally buoyant equipment and personnel. Customized, full-torso manikins were used for performing airway management. Each anesthesiologist-diver attempted airway management on 10 occasions with each device in three experimental conditions: (1) with the manikin at the poolside (poolside); (2) with the submerged manikin floating free (free-floating); and (3) with the submerged manikin fixed to the floor using a restraint (restrained). Airway management failure was defined as failed insertion after three attempts or inadequate device placement after insertion. Results: For the laryngoscope-guided tracheal intubation, airway management failure occurred more frequently in the free- floating (85%) condition than the restrained (8%) and poolside (0%) conditions (both, P 90%), and for the cuffed oropharyngeal airway, laryngeal mask airway, and intubating laryngeal mask airway, it was always a result of inadequate placement. Conclusion: The emphasis placed on the use of restraints for conventional tracheal intubation in microgravity is appropriate. Extratracheal airway devices may be useful when restraints cannot be applied or intubation is difficult

An investigation of endemic goitre during the centuries in sacral figurative arts.

Physical appearances of goitrous people as they appear in figurative sacral arts of Italy are documented and discussed. The investigation is a contribution to historical pathology

Direct measurement of mucosal pressures exerted by cuff and non-cuff portions of tracheal tubes with different cuff volumes and head and neck positions

We measured directly mucosal pressures against the cuff and non-cuff portions of the tracheal tube in different head-neck positions and tested the reliability of calculated mucosal pressures, in vivo intracuff pressures and cuff volume as determinants of directly measured mucosal pressures. We studied 10 anaesthetized, paralysed adult patients. An 8.5-mm, high volume, low pressure PVC tracheal tube was used. Microchip sensors were attached to three cuff locations (anterior, lateral and posterior) and two non-cuff locations (anterior tip and anterior aspect of the tube, 5 cm proximal to the cuff). Directly measured mucosal pressures, in vivo intracuff pressures and calculated mucosal pressures (in vivo minus in vitro intracuff pressures) were determined after brief inflation (< 15 s) to 0, 5, 10 and 15 ml. In vivo intracuff pressures were then set at 30 mm Hg and the measurements repeated, first in the neutral position and then with the head-neck extended, flexed and rotated. Cuff mucosal pressures were highest anteriorly and lowest posteriorly. Non-cuff mucosal pressures did not vary with cuff volume and were approximately 15 mm Hg. Compared with the neutral position, in vivo intracuff pressures were higher in the rotated, extended and flexed positions. Compared with the neutral position, mucosal pressure increased on the anterior aspect of the tube in the flexed position by 22 mm Hg (P = 0.003), at the anterior tip in the extended position by 11 mm Hg (P = 0.002) and at the anterior tip (5 mm Hg, P = 0.05) and lateral aspect of the cuff (5 mm Hg, P = 0.03) in the rotated position. In vivo intracuff pressures and calculated mucosal pressures were moderate predictors of measured mucosal pressures; cuff volume was a poor predictor. We conclude that tracheal mucosal pressures were highest anteriorly, that non-cuff portions of the tube exerted substantial mucosal pressures and that the rotated position caused a greater increase in tracheal mucosal pressure than the extended or flexed position. Indirect methods of measuring mucosal pressure were of moderate predictive value