Ergonomic Consideration in Pillow Height Determinants and Evaluation.

(1) Background: Sleep problems have become one of the current serious public health issues. Pillow height affects the alignment of the cervical spine and is closely related to the mechanical environment of the cervical spine. An appropriate pillow height can provide adequate support for the head and neck to reduce the stress in the cervical spine and relax the muscles of the neck and shoulder, thereby relieving pain and improving sleep quality. (2) Methods: We reviewed the current trends, research methodologies, and determinants of pillow height evaluation, summarizing the evidences published since 1997. In particular, we scrutinized articles dealing with the physiological and mechanical characteristics of the head-neck-shoulder complex. (3) Results: Through the investigation and analysis of these articles, we presented several quantitative and objective determinants for pillow height evaluation, including cervical spine alignment, body dimension, contact pressure, and muscle activity. The measurement methods and selection criteria for these parameters are described in detail. However, the suggested range for achieving optimal cervical spine alignment, appropriate pressure distribution, and minimal muscle activity during sleep cannot yet be identified considering the lack of sufficient evidence. Moreover, there remain no firm conclusions about the optimal pillow height for the supine and lateral positions. (4) Conclusions: A comprehensive evaluation combining the above determinants provides a unique solution for ergonomic pillow design and proper pillow height selection, which can effectively promote the public sleep health. Therefore, it is necessary to develop a reasonable algorithm to weigh multiple determinants.

Effect of Head Elevation to Different Heights in Laryngeal Exposure with Direct Laryngoscopy.

BACKGROUND: The purpose of this study was to determine the optimal pillow height for the best laryngoscopic view in adult patients scheduled for elective surgery under general anaesthesia. METHODS: 150 adult patients undergoing surgery under general anaesthesia with endotracheal intubation with no features suggestive of difficult airway were enrolled for the study. After induction of anaesthesia the assessment of direct laryngoscopic views was done at head positions without a pillow and with non-compressible pillows of heights 5cm and 10cm. RESULTS: The laryngoscopic view with the 5cm pillow was significantly superior to other head position (p<0.01). The incidence of difficult laryngoscopy (Cormack and Lehane grade III) was 32.7% without a pillow which improved to (Cormack and Lehane grade III) 4% with 10cm pillow and there were no cases of difficult laryngoscopy with 5cm pillow. CONCLUSIONS: The use of 5cm pillow in the 'sniffing' position obtains the best laryngoscopic view during direct laryngoscopy.

Impact of pillow height on double-lumen endotracheal tube intubation with McGRATH MAC: a prospective randomized clinical trial.

STUDY OBJECTIVE: This study aimed to compare the impact of pillow height on double-lumen tracheal tube (DLT) intubation with McGRATH MAC (McG) in patients undergoing elective surgery. DESIGN: Randomized clinical trial. SETTING: Operating room. PATIENTS: Fifty adult patients scheduled for elective surgery under 1-lung ventilation with an American Society of Anesthesiologists physical status of 1 to 3. INTERVENTIONS: DLT intubation with McG was performed with a high pillow (HP group; 25 patients) or low pillow (LP group; 25 patients) by anesthesiologists. MEASUREMENTS: Intubation time, number of laryngoscopy, number of tracheal intubation attempts to successful intubation, percentage of glottic opening score, and subjective difficulty of laryngoscopy and tube passage through the glottis were assessed. MAIN RESULTS: Intubation time was significantly shorter in the HP group compared with the LP group (HP: 32.1±14.9seconds vs LP: 49.4±11.2seconds, P<.001). The number of laryngoscopy were 1 (HP group, 22 patients; LP group, 17 patients), 2 (HP group, 3 patient; LP group, 7 patients), and 3 (HP group, 0 patient; LP group, 1 patient), with no significant difference between the 2 groups (P=.197). Although the percentage of glottic opening score did not significantly differ between HP and LP groups (HP: 95.6%±6.7% vs LP: 96.0%±12.3%, P=.08), the number of tracheal intubation attempts was significantly lower in the HP group compared with the LP group (P=.009). The visual analog scale score for laryngoscopy did not significantly differ between the 2 groups (P=.54). However, the visual analog scale for tube passage through the glottis was significantly higher in the LP group than in the HP group (P<.001). CONCLUSIONS: Intubation with an HP was associated with a better DLT intubation profile than with an LP with McG, possibly due to smoother tracheal tube progression through the glottis.