Open AccessObservations from the IMPROVE trial concerning the clinical care of patients with ruptured abdominal aortic aneurysm
Author(s) -
Improve trial investigators,
J.T. Powell,
Robert J. Hinchliffe,
Matthew M. Thompson,
Michael Sweeting,
Raymond Ashleigh,
Rachel Bell,
Manuel Gomes,
Roger M. Greenhalgh,
Richard Grieve,
Francine Heatley,
Simon G. Thompson,
Pinar Ulug
Publication year - 2014
Publication title -
british journal of surgery
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.202
H-Index - 201
eISSN - 1365-2168
pISSN - 0007-1323
DOI - 10.1002/bjs.9410
Subject(s) - medicine , odds ratio , aneurysm , endovascular aneurysm repair , randomized controlled trial , abdominal aortic aneurysm , confidence interval , surgery , blood pressure , confounding , presentation (obstetrics) , general anaesthesia
Background Single‐centre series of the management of patients with ruptured abdominal aortic aneurysm ( AAA ) are usually too small to identify clinical factors that could improve patient outcomes.Methods IMPROVE is a pragmatic, multicentre randomized clinical trial in which eligible patients with a clinical diagnosis of ruptured aneurysm were allocated to a strategy of endovascular aneurysm repair ( EVAR ) or to open repair. The influences of time and manner of hospital presentation, fluid volume status, type of anaesthesia, type of endovascular repair and time to aneurysm repair on 30‐day mortality were investigated according to a prespecified plan, for the subgroup of patients with a proven diagnosis of ruptured or symptomatic AAA . Adjustment was made for potential confounding factors.Results Some 558 of 613 randomized patients had a symptomatic or ruptured aneurysm: diagnostic accuracy was 91·0 per cent. Patients randomized outside routine working hours had higher operative mortality (adjusted odds ratio ( OR ) 1·47, 95 per cent confidence interval 1·00 to 2·17). Mortality rates after primary and secondary presentation were similar. Lowest systolic blood pressure was strongly and independently associated with 30‐day mortality (51 per cent among those with pressure below 70 mmHg ). Patients who received EVAR under local anaesthesia alone had greatly reduced 30‐day mortality compared with those who had general anaesthesia (adjusted OR 0·27, 0·10 to 0·70).Conclusion These findings suggest that the outcome of ruptured AAA might be improved by wider use of local anaesthesia for EVAR and that a minimum blood pressure of 70 mmHg is too low a threshold for permissive hypotension.