Related Experiment Video
Updated: May 13, 2026

An Educational Video Demonstration of How to Prone a Critically Ill Intubated Patient
Published on: November 30, 2022
Factors associated with low adherence to head-of-bed elevation during mechanical ventilation in Chinese intensive
Jing-tao Liu1, Hai-jing Song, Yu Wang
1Department of Critical Care Medicine, 309th Hospital of Chinese Peoples' Liberation Army, Beijing 100091, China.
Background:
Elevating the head of bed (HOB) 30° - 45° has been widely supported as a means of ventilator associated pneumonia (VAP) prevention. However, it was poorly adhered in clinical practice. This observational study aimed to investigate the factors impeding this simple practice at the bedside.
Methods:
This prospective study was conducted in 33 Chinese academic hospital intensive care units (ICUs). HOB angle was measured four times daily at 5 - 7 hour intervals. The predefined HOB elevation goal was an angle ≥ 30°.
Results:
The overall rate of achieving the HOB goal was 27.8% of the 8647 measurements in 314 patients during 2842 ventilation days. The HOB goal of ≥ 3 times/d was consistently achieved only in 15.9% of the cases. Almost 60% of patients had at least one 24 hours period during which the HOB goal was never documented. This low rate of protocol compliance was not associated with acute physiology and chronic health evaluation (APACHE) II score or dependence on vasopressors. In a survey, "nurse workload" was identified as the most important factor for non-compliance with the HOB goal. In addition, the rates of compliance were significantly different (P < 0.001) between physicians self-reporting that they either did or did not know the Institutes of Healthcare Improvement (IHI) ventilator bundle.
Conclusions:
Low adherence to a HOB angle of ≥ 30° was found in this nationwide survey. Nursing workload and lack of knowledge on VAP prevention were important barriers to changing this practice.
Related Concept Videos
Acute Respiratory Failure-IV
Mechanical Ventilation I: Indication and Settings
Mechanical Ventilation III: Noninvasive Ventilation
Noninvasive Positive-Pressure Ventilation (NIPPV)
Acute Respiratory Failure-III
Cardiopulmonary Resuscitation II: ACLS Airway Management
Factors Affecting Pulmonary Ventilation
Alveolar Surface Tension
The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each...
