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Gregory Fischer

Publications and source records attributed to Gregory Fischer.

2 recordsLinked to original sources

Effective management of refractory postcardiotomy bleeding with the use of recombinant activated factor VII.

BACKGROUND: Severe coagulopathy after cardiovascular surgery may lead to intractable bleeding and is associated with increased mortality and morbidity. Recent studies have suggested that recombinant activated factor VII (rFVIIa) may play a role in decreasing postoperative bleeding. Herein we report our experience with the off-label use of rFVIIa in patients with refractory postcardiotomy bleeding. METHODS: From June 2003 to December 2005, 17 patients (mean age, 65 +/- 18 years) received rFVIIa for refractory bleeding after cardiac surgery. Preoperative risk factors for bleeding included reoperation (n = 7), emergency surgery (n = 7), and renal or hepatic failure (n = 3). Surgical procedures were aortic surgery (n = 7), complex valve operations (n = 7), coronary artery bypass grafting (n = 2), and cardiac tumor resection (n = 1). RESULTS: The average dose of rFVIIa was 103.1 +/- 30.2 microg/kg. After the administration of rFVIIa the blood loss was reduced and chest tube output decreased from an average of 300 mL/h to 60 mL/h (p = 0.024). Coagulation variables normalized (mean prothrombin time, 18 +/- 7 versus 14 +/- 3 seconds; p = 0.03; mean partial thromboplastin time, 94 +/- 50 versus 49 +/- 14 seconds; p = 0.02), and the need for blood products was significantly reduced. Only 1 patient required mediastinal reexploration. No thromboembolic complications occurred during hospitalization. CONCLUSIONS: This study suggests that rFVIIa is safe and efficacious in the management of refractory postcardiotomy bleeding. The use of rFVIIa is associated with reduced blood loss, rapid improvement of coagulation variables, and decreased need for blood products. Further studies are necessary to determine the safety and efficacy of this new hemostatic agent and its precise role in the treatment of severe postoperative coagulopathy.

Adult↗

Image overlay for CT-guided needle insertions.

OBJECTIVE: We present a 2D image overlay device to assist needle placement on computed tomography (CT) scanners. MATERIALS AND METHODS: The system consists of a flat display and a semitransparent mirror mounted on the gantry. When the physician looks at the patient through the mirror, the CT image appears to be floating inside the body with correct size and position as if the physician had 2D 'X-ray vision'. The physician draws the optimal path on the CT image. The composite image is rendered on the display and thus reflected in the mirror. The reflected image is used to guide the physician in the procedure. In this article, we describe the design and various embodiments of the 2D image overlay system, followed by the results of phantom and cadaver experiments in multiple clinical applications. RESULTS: Multiple skeletal targets were successfully accessed with one insertion attempt. Generally, successful access was recorded on liver targets when a clear path opened, but the number of attempts and accuracy showed variability because of occasional lack of access. Soft tissue deformation further reduced the accuracy and consistency in comparison to skeletal targets. CONCLUSION: The system demonstrated strong potential for reducing faulty needle insertion attempts, thereby reducing X-ray dose and patient discomfort.

Animals↗