Head-position angles in children for opening the upper airway

Abstract

Aims

Inexperienced health-care-providers may encounter severe problems to ventilate an unconscious child. Designing a ventilating device that could indicate how to open an upper airway correctly may be beneficial. Neutral position in young children and slight head extension in older children is recommended, although the optimal head angle is not clear. Thus, we compared effects of neutral head position and extension, measuring head-position angles and ventilation parameters.

Methods

Sixty-one children scheduled for tonsillectomy were enrolled, and were ventilated with pressure-controlled ventilation after anaesthesia induction.

Results

Children were divided into two groups: 1–5 years old (pre-school children, n = 38) and 6–10 years old (school children, n = 23). In neutral (mean ± SD: 1.3 ± 6.0) vs. head-extension position (13.2 ± 6.0; P < 0.001) in pre-school children, tidal volumes (132 ± 44,137 ± 49 ml), peak-expiratory flow (300 ± 90 vs. 310 ± 100 ml s⁻¹) and expiratory airway resistance (20 ± 8 vs. 18 ± 6 cmH₂O s l⁻¹) were comparable (P = NS). In neutral (−0.4 ± 5.4) vs. head-extension position (15.7 ± 6.4; P < 0.001) in school children, expiratory airway resistance (17 ± 7 vs. 13 ± 5 cmH₂O s l⁻¹; P = 0.048) differed, while tidal volume (224 ± 93 vs. 230 ± 92 ml) and peak-expiratory flow (427 ± 181 vs. 381 ± 144 ml s⁻¹) were comparable (P = NS).

Conclusions

Head-extension and neutral head-position angles differed in pre-school and school children. In pre-school children, neutral head position or head extension with an angle of −1° or 13°, and in school children head extension of 16°, may be used to achieve optimal ventilation of an unprotected airway.

Introduction

Ventilation may improve survival during cardiac arrest.¹ However, the ability to open and to maintain the airway patent is necessary to ensure efficient ventilation in an unconscious child with an unprotected airway. In a paediatric emergency, airway patency and bag–valve–mask ventilation are of utmost importance because a paediatric, when compared to an adult, cardiac arrest very likely is secondary to hypoxia, making oxygen delivery essential.2, 3 To open the upper airway of an unconscious pre-school child, positioning the head in a neutral head position is recommended, while in an unconscious school child an extended-head position is recommended.⁴ Interestingly, there are no clinical data to support this recommendation. If optimal head positions in pre-school and school children could be ascertained in a study in the operating room, they could then be extrapolated to the field by incorporating a built-in indicator within a bag–valve–mask device.⁵ Since retention of ventilation skills after training is low,6, 7 this strategy of incorporating self-explanatory features may improve built-in safety when managing an unprotected airway in pre-school and school children.

This study aimed to determine head-position angles reflecting a neutral position, and head extension in unconscious supine pre-school and school children to design a bag–valve–mask device to optimise ventilation of an unprotected upper airway.