The SIAP study will evaluate the effect of the use of Ergotrics' Inflatable Prone Supports (IPS) on the Intra-Abdominal Pressure (IAP) during spinal surgery.
Read the study summary
Spine-Intra-Abdominal Pressure (SIAP) study
(Prospective, observational, single-arm, monocenter study)
The objective of this study is to demonstrate the ability of the inflatable Prone Supports (IPS) to lower the IAP of patients in the prone position. Whenever the patients' position is changed to prone, the IAP is increased due to abdominal compression.
It has been demonstrated previously that an increased IAP is linked to increased bleeding. The ability to reduce IAP will be assessed by measuring IAP before and after inflation of the IPS.
The METC (Medical Ethics Review Committee) has approved the SIAP study submitted by dr. van Eijs (anesthesiologist at ETZ, Tilburg, The Netherlands). The study will enroll 40 patients, aged between 18-70 and a body weight < 120 kg.
What is IAP?
Intra-abdominal pressure (IAP) is defined as the steady-state pressure within the abdominal cavity. Under physiological conditions, values of up to 5 mmHg are considered normal in adults. The incidence of complications arising from increased IAP in critically ill patients, is high and its impact is significant. IAP impacts the cerebrospinal venous system and the jugular venous system via two pathways (see fig. 1).
Fig 1. The concept of the two pathways. In the first pathway, an increase in IAP can cause backflow through the sacral venous plexus and the vertebral venous into the spinal canal. This can cause congestion of venous blood in the spinal canal and can cause flow of venous blood into the brain. In the second pathway, an increase in IAP can cause an increase in ITP (intrathoracic pressure) which in turn results in a back pressure on the jugular veins and decreases the drainage of the CSF (Cerebrospinal fluid) and the venous blood.
How is IAP measured?
The enrolled patients undergo spine surgery in prone position and have a transurethral bladder catheter during the procedure. The urinary catheter will be used to measure the IAP. The urinary bladder pressures reflects well the pressures in the abdominal cavity.
The IPS cushion is designed as a mirror image of the human skeleton. In this way it supports the ribcage and pelvis, while leaving the abdomen free. Patients are positioned in a manner to offload the abdomen as much as possible to avoid an increased IAP.
How do the IPS supports for prone surgery reduce the IAP?
Ergotrics is a Med-Tech company which specializes in the use of compressed air in healthcare. We develop and manufacture products which allow for optimal positioning or moving of patients. Without heavy physical labour and with special attention given to ease of use, patient safety and hygiene.