Blood loss and transfusion in elective abdominal aortic aneurysm surgery

347

261

DEFINITION OF THE PROBLEM Purpose of these guidelinesThe Clinical Practice Council of the Society for Vascular Surgery charged a writing committee with the task of updating practice guidelines, initally published in 2003, for surgeons and physicians who are involved in the preoperative, operative, and postoperative care of patients with abdominal aortic aneurysms (AAA). 1 This article is an executive summary of the main practice guidelines document and provides recommendations for evaluating the patient, including risk of aneurysm rupture and associated medical co-morbidities, guidelines for selecting surgical or endovascular intervention, intraoperative strategies, perioperative care, longterm follow-up, and treatment of late complications. 2 Decision making related to the care of patients with AAA is complex. Aneurysms present with varying risks of rupture, and patient-specific factors influence anticipated life expectancy, operative risk, and the need to intervene. Careful attention to the choice of operative strategy, as influenced by anatomic features of the AAA, along with optimal treatment of medical co-morbidities is critical to achieving excellent outcomes. Moreover, appropriate postoperative patient surveillance and timely intervention in the case of a late complication is necessary to minimize subsequent aneurysm-related death or morbidity. All of these clinical decisions are determined in an environment where cost-effectiveness will ultimately dictate the ability to provide optimal care to the largest possible segment of the population. Currently available clinical data sets have been reviewed in formulating these recommendations. However, an important goal of this document is to clearly identify those areas where further clinical research is necessary. Methodology and evidenceA comprehensive review of the available clinical evidence in the literature was conducted in order to generate a concise set of recommendations. The strength of any given recommendation and the quality of evidence was scored based on the GRADE system (Table). 3 When the benefits of an intervention outweighed its risks, or, alternatively, risks outweighed benefits, a strong recommendation was noted. However, if benefits and risks were less certain, either because of low quality evidence or because high quality evidence suggests benefits and risks are closely balanced, a weak recommendation was recorded. The quality of evidence that formed the basis of these recommendations was scored as high, moderate, or low. Not all randomized controlled trials are alike and limitations may compromise the quality of their evidence. In addition, if there is a large magnitude of effect, the quality of evidence derived from observational studies may be high. Thus, quality of evidence was scored as high when additional research is considered very unlikely to change confidence in the estimate of effect; moderate when further research is likely to have an important impact on in the

Section: Hematologic Disordersmentioning

confidence: 93%

SVS practice guidelines for the care of patients with an abdominal aortic aneurysm: Executive summary

Chaikof

Brewster

Dalman

et al. 2009

347

261

“…79, 106 Ho and colleagues 106 documented that a hemoglobin level of less than 10.5 g/dL was an independent determinant of blood loss. A hematocrit less than 28% has also been associated with an increased incidence of postoperative MI in patients undergoing vascular surgery.…”

Section: Level Of Recommendation: Strong Quality Of Evidence: Lowmentioning

confidence: 98%

“…108 While not specifically addressing the impact on mortality, Ho and others did document in 129 patients undergoing elective AAA repair that a platelet count of 130,000 platelets/L or less was associated with increased risk of bleeding. 106 In addition, it is well recognized that following aortic clamping, platelet sequestration and thrombocytopenia occur in the early postoperative period. Patients subsequently develop hyperfibrinogenaemia and thrombocytosis, which may persist for several weeks.…”

Section: Level Of Recommendation: Strong Quality Of Evidence: Lowmentioning

confidence: 99%

The care of patients with an abdominal aortic aneurysm: The Society for Vascular Surgery practice guidelines

Chaikof

Brewster

Dalman

et al. 2009

625

520

DEFINITION OF THE PROBLEM Purpose of these guidelinesThe Clinical Practice Council of the Society for Vascular Surgery charged a writing committee with the task of updating practice guidelines, initally published in 2003, for surgeons and physicians who are involved in the preoperative, operative, and postoperative care of patients with abdominal aortic aneurysms (AAA). 1 This document provides recommendations for evaluating the patient, including risk of aneurysm rupture and associated medical co-morbidities, guidelines for selecting surgical or endovascular intervention, intraoperative strategies, perioperative care, long-term follow-up, and treatment of late complications.Decision making related to the care of patients with AAA is complex. Aneurysms present with varying risks of rupture and patient specific factors influence anticipated life expectancy, operative risk, and the need to intervene. Careful attention to the choice of operative strategy, as influenced by anatomic features of the AAA, along with optimal treatment of medical co-morbidities is critical to achieving excellent outcomes. Moreover, appropriate postoperative patient surveillance and timely intervention in the case of a late complication is necessary to minimize subsequent aneurysm-related death or morbidity. All of these clinical decisions are determined in an environment where cost-effectiveness will ultimately dictate the ability to provide optimal care to the largest possible segment of the population. Currently available clinical data sets have been reviewed in formulating these recommendations. However, an important goal of this document is to clearly identify those areas where further clinical research is necessary. Methodology and evidenceA comprehensive review of the available clinical evidence in the literature was conducted in order to generate a concise set of recommendations. The strength of any given recommendation and the quality of evidence was scored based on the GRADE system (Table I). 2 When the benefits of an intervention outweighed its risks, or, alternatively, risks outweighed benefits, a strong recommendation was noted. However, if benefits and risks were less certain, either because of low quality evidence or because high quality evidence suggests benefits and risks are closely balanced, a weak recommendation was recorded. The quality of evidence that formed the basis of these recommendations was scored as high, moderate, or low. Not all randomized controlled trials are alike and limitations may compromise the quality of their evidence. In addition, if there is a large magnitude of effect, the quality of evidence derived from observational studies may be high. Thus, quality of evidence was scored as high when additional research is considered very unlikely to change confidence in the estimate of effect; moderate when further research is likely to have an important impact in the estimate of effect; or low when further research is very likely to change the estimate of the effect.

“…Surgeon fatigue may be associated with errors of both judgment and technique. 11, 12 Clagett has emphasized the benefit of using a two-team approach to complete the entire NAIS procedure: harvest the deep veins, obtain vascular control in a hostile abdomen, excise the infected graft, repair associated bowel injuries, and then perform complex revascularization.…”

mentioning

confidence: 99%

Staging the neoaortoiliac system: Feasibility and short-term outcomes

Ali

McLeod

Kalapatapu

et al. 2008