Morbid Obesity Impairs Adequacy of Thoracic Compressions in a Simulation-Based Model

Abstract

Adequate cardiopulmonary resuscitation is an important predictor of survival, however, obesity provides a significant physical barrier to thoracic compressions. This study explores the effect of morbid obesity on compression adequacy. We performed a prospective randomised controlled crossover study, assessing the adequacy of thoracic compressions on a manikin modified to emulate a morbidly obese patient. Participants recruited from critical care departments were randomised to perform continuous compressions for two minutes on each manikin. Accelerometers were used to measure thoracic wall movement. The primary endpoint was a composite measure of compression adequacy (rate, depth and recoil). Secondary endpoints were the individual components of the composite outcome and measures of perceived effectiveness, fatigue, and pain. One hundred and one participants were recruited. There was a significant difference between the obese and control groups in the composite endpoint (4% versus 30%, P <0.001), as well as the individual components of adequacy (P <0.01 for all). Quartile data showed significant deterioration in adequacy of depth and recoil in both groups, and this occurred significantly earlier in the obese group (P ≤0.001). Participants' perception of effectiveness was significantly lower (P ≤0.001) in the obese group, and levels of fatigue (P ≤0.001) and pain (P ≤0.001) significantly higher. Morbid obesity impairs the adequacy of thoracic compressions for trained rescuers in a simulation-based model. Participants were not fully aware of how ineffective compressions were. There is evidence of earlier fatigue further reducing effectiveness. These findings have significant implications for the training of rescuers in a clinically relevant population and the planning of future research.

Emergencies in obese patients: a narrative review

“…The use of mechanical chest compression devices might be considered although body dimensions and slope of the anterior chest wall limit usability of most devices. The upper limits include sternum height of 303 or 340 mm and chest width of 449 or 480 mm for piston devices, chest circumference of 130 cm, chest width of 380 mm, and body weight of 136 kg for devices equipped with a load-distributing band [ 68 , 69 ].…”