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Updated: Jun 19, 2026

Ultrasonographic Assessment During Cardiopulmonary Resuscitation
Published on: October 24, 2020
Effects of bed height on the performance of chest compressions
1Department of Emergency Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
Objectives:
The correct chest compression technique was emphasised to enhance the result of cardiopulmonary resuscitation in the 2005 guidelines. The present study compared the effects of different bed heights, including a bed at knee height, on the performance of chest compressions.
Methods:
Twenty-four healthcare providers participated in this study. Knee height was defined as the baseline bed height. Bed heights were adjusted to 10 and 20 cm above the baseline and 10 and 20 cm below the baseline. At the five bed heights, chest compressions were performed for 2 minutes, and the compression rate was maintained at 100 per minute, with audible feedback.
Results:
The mean compression depths (MCD) were 28.3 mm (SD 10.7; knee height +20 cm), 32.3 mm (SD 9.2; knee height +10 cm), 32.7 mm (SD 8.5; knee height), 32.3 mm (SD 9.0; knee height -10 cm) and 31.1 mm (SD 8.5; knee height -20 cm). The MCD was significantly lower at knee height plus 20 cm (p<0.001).
Conclusion:
The performance of chest compressions decreased when the bed height was 20 cm higher than the knee height of the rescuer.
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Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.
Factors Affecting Respiration
Measurement of Blood Pressure
Anatomical Positions
The body is upright, facing forward, and standing erect.
The feet are parallel and flat on the floor.
The arms are hanging by the...

