Hypotensive hemostatis (permissive hypotension) for ruptured abdominal aortic aneurysm: are we really in control?

The purpose of this study was to investigate whether a protocol for permissive hypotension was feasible for patients admitted with a ruptured abdominal aortic aneurysm (RAAA). It was aimed to limit prehospital intravenous fluid administration to 500 mL and to maintain systolic blood pressure at a range of 50 to 100 mm Hg following admission, using nitrates when indicated. The diagnosis of RAAA was confirmed with sonography, and all patients with uncontrolled hypovolemic shock immediately underwent open aneurysm repair (OAR). In all other cases, computed tomographic (CT) angiography was performed to determine the eligibility for endovascular aneurysm repair (EVAR). From January 1, 2004, to December 31, 2006, 95 patients with a suspected RAAA were admitted. In 77 patients, the diagnosis of RAAA was confirmed. Twenty-eight cases (36%) underwent OAR for uncontrolled hemodynamic instability. Following CT-angiographic evaluation, 25 of the remaining 49 cases were considered unsuitable for EVAR and subsequently underwent OAR. In 24 of 77 cases (31%), the RAAA was treated with EVAR. Preoperative systolic blood pressure recordings in EVAR patients showed median values (+/- SD) of 98 (+/- 34.7) mm Hg in the emergency department and 114 (+/- 26.2) mm Hg in the operating theater. The desired systolic blood pressure range of 50 to 100 mm Hg was reached in 11 of 24 cases (46%). In 13 of 24 cases (54%), a systolic blood pressure higher than 100 mm Hg was recorded for a period longer than 60 minutes. The 30-day mortality was 32 of 77 (42%), with 6 of 24 (25%) in the EVAR group and 26 of 53 (49%) in the OAR group. This is the first published series of RAAA in which a protocol of permissive hypotension has been adopted. The concept appeared to be feasible in the majority of cases. Protocol violations were sparse (n = 5). Uncontrolled hypotension occurred in 36% (28 of 77) of all patients, and the desired systolic blood pressure range was achieved in 46% (11 of 24) of the EVAR patients.