The spine intra-abdominal pressure (SIAP) trial. A prospective, observational, single arm, monocenter study looking at the evolutions of the IAP prior, during and after spine surgery

Background and aims: Both anaesthesiologists and spine surgeons consider the intra-abdominal pressure (IAP) as an important peri-operative factor affected by patient positioning.We assessed the change in IAP caused by using a thoraco pelvic support (inflatable prone support, IPS) with the subject under general anesthesia. The IAP was measured before, during and immediately after surgery.Methods: The Spine Intra-Abdominal Pressure study (SIAP trial) is a prospective, single-arm, monocenter, observational study looking at changes in IAP prior, during and after spine surgery. The objective is to assess the change in IAP, measured via an indwelling urinary catheter, using the inflatable prone support (IPS) device during prone positioning of patients in spinal surgery.Results: Forty (40) subjects requiring elective lumbar spine surgery in prone position were enrolled after providing informed consent. The inflation of the IPS results in a significant decrease of IAP (from a median of 9.2 mmHg to 6.46 mmHg (p < 0.001)) in patients undergoing spine surgery in prone position. This decrease in IAP was maintained throughout the procedure despite the discontinuation of muscle relaxants. No serious adverse events or unexpected adverse events occurred.Conclusion: The use of the thoraco-pelvic support IPS device was able to significantly lower the IAP during spine surgery.