Pressure distribution of intraoperative chest pad designs in patients with adolescent idiopathic scoliosis.

ABSTRACT

STUDY DESIGN: A prospective, comparative study. OBJECTIVE: To evaluate the resultant force and pressure distribution between chest pad designs for scoliosis patients while in the prone position. SUMMARY OF BACKGROUND DATA Scoliosis affects the anatomy of the lungs and the chest wall, which can adversely affect pulmonary function. Scoliosis surgery requires that patients remain prone for several hours with their body weight supported by pads under the chest and pelvis. As a significant portion of the patient's weight is on the chest, this extrinsic pressure may further affect the pulmonary status of already compromised lungs. METHODS: Fourteen female subjects with right main thoracic adolescent idiopathic scoliosis of at least 45 degrees were evaluated. A Jackson Spinal Surgery and Imaging Table (Orthopaedic Systems Inc.) was used with commercially available (Vista Medical) pressure transducer mats that were overlaid on the chest and hip supports. Awake subjects were positioned on the table during 2 testing conditions 1 chest pad versus 2 chest pads on the table. Over a 60-second testing period for each condition, the average and maximum pressures and resultant force were found for each pad. RESULTS: The 1 and 2 pad systems had average chest pressures of 4.51±1.07 versus 3.10±0.64 kPa (P<0.05), and maximum chest pressures of 12.9±3.1 versus 9.44±3.14 kPa (P<0.05). The 1 and 2 pad systems had average pelvic pressures of 2.67±0.57 versus 2.98±0.56 kPa (P<0.05), and maximum pelvic pressures of 15.1±7.8 versus 19.4±0.8 kPa (P<0.05). CONCLUSIONS: The 2 pad chest support system resulted in lower maximum and average pressures at the chest and higher maximum and average pressures at the pelvis as compared with the 1 pad design.