Treatment of intracranial hypertension using nonsurgical abdominal decompression

Background: Elevated intra-abdominal pressure (IAP) increases intracranial pressure (ICP) and reduces cerebral pel fusion pressure (CPP). We evaluated a nonsurgical means of reducing IAP to reverse this process, Methods: Swine with a baseline ICP of 25 mm Hg produced by an intracranial balloon catheter were studied. In group 1 (n = 5), IAP was increased by 25 mm Hg. Continuous negative abdominal pressure (CNAP) was then applied, Group 2 (n = 4) had neither IAP elevation nor CNAP. Group 3 (n = 4) had CNAP without IAP elevation. Results: Elevation of IAP by 25 mm Hg above baseline led to deleterious changes in ICP (25.8 +/- 0.8 to 39.0 +/- 2.8; p < 0.05) and CPP (85.2 +/- 2.0 to 64.8 +/- 2.6; p < 0.05), CNAP led to a reduction in IAP (30.2 +/- 1.2 to 20.4 +/- 1.3: p < 0.05) and improvements in cerebral perfusion (ICP, 33 +/- 2.7; CPP, 74.4 +/- 1.2; both p < 0.05). Group 2 had stable ICP (25.8 +/- 0.25 to 28.7 +/- 1.7: p > 0.05) and CPP (80.8 +/- 1.4 to 80.5 +/- 1.8; p > 0.05. In group 3, CNAP decreased cardiac index (2.9 +/- 0.2 to 1.1 +/- 0.4; p < 0.05). mean arterial pressure (105.2 +/- 4.0 to 38.2 +/- 12.0; p < 0.05), and CPP (74.2 +/- 4.7 to 14.5 +/- 12.2; p < 0.05). Conclusion: Elevations in IAP led to increased ICP and decreased CPP, CNAP ameliorated these intracranial disturbances, With normal IAP, CNAP impaired cerebral perfusion.