Effects of bed height on the performance of endotracheal intubation and bag mask ventilation

Objectives. This study was performed to evaluate whether different bed heights af-fect the performance of airway procedures.

Methods. Thirty three medical doctors performed endotracheal intubation (EI) and bag mask ventilation (BMV) using three different bed heights; knee height, mid-thigh height, and anterior superior iliac spine (ASIS) height. For EI, perfor-mance was assessed based on intubation time, intubation success, and damage to teeth. For BMV, performance was assessed based on tidal volume, ventilation rate, peak pressure, minute ventilation, and air-way opening. In addition, three numeric rating scales (NRS; 1 to 10) were used to assess the level of difficulty for each proce-dure and the doctors’ self-confidence. NRS scoring was based on posture (comfort-able to uncomfortable), handling (easy to hard), and visual field (good to bad).

Results. No significant differences in per-formance were observed for EI or BMV at the three different bed heights. How-ever, all of the NRS scores were signifi-cantly different among the different bed heights (P<0.001), and were poorest for the knee height beds: knee height (EI: pos-ture 5.8~7.3, handling 4.3~5.7, visual field 3.9~5.5; BMV: posture 7.1~8.0, handling 5.9~7.2, 95% CI), mid-thigh height (EI: posture 2.9~4.0, handling 2.9~4.0, visual field 2.7~3.8; BMV: posture 2.4~3.2, han-dling 2.3~3.5) and ASIS height (EI: pos-ture 2.2~3.5, handling 2.6~3.8, visual field 2.1~3.4; BMV: posture 2.9~4.4, handling 4.7~6.1).

Conclusions. Although the participants re-ported that the knee height beds were the least comfortable, hardest to handle, and made seeing the vocal cord difficult, these caveats did not affect their performance during airway procedures.

endotracheal intubation, posi-tive pressure ventilation, bed, cardiopulmo-nary resuscitation

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