Background: Emergency oral tracheal intubations in the pre-hospital setting can be more difficult because the rescuer's position with respect to a patient lying on the ground may not provide optimal conditions for intubation. Since optimal visualisation of the larynx often depends on the force generated during laryngoscopy, we measured the pressure required for intubation (P(i)) as well as the maximum pressure (P(max)) that can be generated with the laryngoscopy blade in seven intubator positions.
Methods: Nineteen hospital personnel with intubation experience participated in this study. A modified #3 Macintosh laryngoscope blade was used to measure the pressure exerted on the tongue of a manikin placed on the ground during intubation. The following positions were studied: standard, sitting, prone, kneeling, left and right lateral decubitus and straddling.
Results: Intubating in the straddling position required the lowest P(i), as a percent of P(max) (68+/-14%). This was significantly less than the prone, right lateral decubitus and sitting positions. (Tukey's W procedure, P<0.05)
Conclusion: The straddling position affords the intubator significantly more reserve force than the prone, right lateral decubitus or sitting position. We suggest that the straddling position may be an advantageous position for pre-hospital intubations especially when visualisation of the glottis is difficult.