Surgery adds risk of perioperative bleeding
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Platelet inhibition test helps predict surgical bleeding

SAN FRANCISCO – Preoperative light transmission aggregometry assessments of platelet aggregation may help identify which patients on dual antiplatelet therapy are at greater risk of sustained bleeding from noncardiac surgery, a prospective study of 147 consecutive patients suggests.

The light transmission aggregometry (LTA) assessments of blood drawn immediately before noncardiac surgery were significantly lower in the 32% of patients with sustained bleeding than in the other patients.

All patients were on dual antiplatelet therapy, 95% of them on maintenance therapy with aspirin plus clopidogrel. Timing of the surgery was at the discretion of the surgeons. Treating physicians were blinded to LTA results. The mean preoperative washout period for dual antiplatelet therapy was 1.5 days. Patients had vascular (76%), orthopedic (10%), abdominal (7%), or other (7%) surgery.

The ongoing study might help define a "bleeding cutoff" measure by LTA to better individualize the timing of surgery, Dr. Wolfgang Toller and his colleagues said in a poster session at the annual meeting of the American Society of Anesthesiologists.

In general, approximately 5% of patients in their first year of dual antiplatelet therapy undergo noncardiac surgery, which creates a conundrum for management. Discontinuing dual antiplatelet therapy before noncardiac surgery has been associated with a 20% risk of major adverse cardiac events, but there’s a 20%-40% risk of moderate to severe bleeding if dual antiplatelet therapy is continued during noncardiac surgery, said Dr. Toller of the Medical University of Graz, Austria.

The 147 patients in the study underwent vascular surgery (76%), orthopedic surgery (10%), abdominal surgery (7%), or other surgical procedures (7%). All had been on P2Y12 receptor inhibitors within 7 days before surgery.

Investigators used the Chronolog 700 Lumi-Aggregometer to assess platelet aggregation in preoperative blood, using 5 mcm of adenosine diphosphate as the specific inductor for platelet aggregation.

Overall, they found an average 40% maximum change in light transmission from baseline after adding the adenosine diphosphate to blood samples. In patients with increased bleeding, however, the mean maximum change in light transmission was approximately 30% (suggesting less platelet aggregation), compared with a more than 40% change in patients who bled less from the surgery.

Dr. Toller reported having no financial disclosures.

Surgery adds risk of perioperative bleeding

Dr. Lary Robinson, FCCP, comments: The vast majority of patients on dual platelet therapy (aspirin plus another agent such as clopidogrel) have had implantation of a drug-eluting coronary stent, who need to remain on this regimen for 1 year, after which it may be safely reduced to aspirin alone in most cases. In this first year, urgent surgery, such as that needed for cancer, as well as vascular surgery for ischemia or trauma, comes with the added risk of significant perioperative bleeding.

Anesthesiologists Wolfgang Toller and associates describe using the in vitro platelet function test, called light transmission aggregometry, in 147 patients. When used just prior to surgery, the test was somewhat predictive of which patients were at elevated bleeding risk. They propose that this test may better define and individualize the timing of surgery. However, the differences in test results are small and recommendations are not yet definite. Nevertheless, refinements in testing may lead to more specific recommendations about which patients should have surgery postponed due to a much greater bleeding risk.

sboschert@frontlinemedcom.com

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Dr. Lary Robinson, FCCP, comments: The vast majority of patients on dual platelet therapy (aspirin plus another agent such as clopidogrel) have had implantation of a drug-eluting coronary stent, who need to remain on this regimen for 1 year, after which it may be safely reduced to aspirin alone in most cases. In this first year, urgent surgery, such as that needed for cancer, as well as vascular surgery for ischemia or trauma, comes with the added risk of significant perioperative bleeding.

Anesthesiologists Wolfgang Toller and associates describe using the in vitro platelet function test, called light transmission aggregometry, in 147 patients. When used just prior to surgery, the test was somewhat predictive of which patients were at elevated bleeding risk. They propose that this test may better define and individualize the timing of surgery. However, the differences in test results are small and recommendations are not yet definite. Nevertheless, refinements in testing may lead to more specific recommendations about which patients should have surgery postponed due to a much greater bleeding risk.

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Dr. Lary Robinson, FCCP, comments: The vast majority of patients on dual platelet therapy (aspirin plus another agent such as clopidogrel) have had implantation of a drug-eluting coronary stent, who need to remain on this regimen for 1 year, after which it may be safely reduced to aspirin alone in most cases. In this first year, urgent surgery, such as that needed for cancer, as well as vascular surgery for ischemia or trauma, comes with the added risk of significant perioperative bleeding.

Anesthesiologists Wolfgang Toller and associates describe using the in vitro platelet function test, called light transmission aggregometry, in 147 patients. When used just prior to surgery, the test was somewhat predictive of which patients were at elevated bleeding risk. They propose that this test may better define and individualize the timing of surgery. However, the differences in test results are small and recommendations are not yet definite. Nevertheless, refinements in testing may lead to more specific recommendations about which patients should have surgery postponed due to a much greater bleeding risk.

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Dr. Lary Robinson, FCCP, comments: The vast majority of patients on dual platelet therapy (aspirin plus another agent such as clopidogrel) have had implantation of a drug-eluting coronary stent, who need to remain on this regimen for 1 year, after which it may be safely reduced to aspirin alone in most cases. In this first year, urgent surgery, such as that needed for cancer, as well as vascular surgery for ischemia or trauma, comes with the added risk of significant perioperative bleeding.

Anesthesiologists Wolfgang Toller and associates describe using the in vitro platelet function test, called light transmission aggregometry, in 147 patients. When used just prior to surgery, the test was somewhat predictive of which patients were at elevated bleeding risk. They propose that this test may better define and individualize the timing of surgery. However, the differences in test results are small and recommendations are not yet definite. Nevertheless, refinements in testing may lead to more specific recommendations about which patients should have surgery postponed due to a much greater bleeding risk.

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Surgery adds risk of perioperative bleeding
Surgery adds risk of perioperative bleeding

SAN FRANCISCO – Preoperative light transmission aggregometry assessments of platelet aggregation may help identify which patients on dual antiplatelet therapy are at greater risk of sustained bleeding from noncardiac surgery, a prospective study of 147 consecutive patients suggests.

The light transmission aggregometry (LTA) assessments of blood drawn immediately before noncardiac surgery were significantly lower in the 32% of patients with sustained bleeding than in the other patients.

All patients were on dual antiplatelet therapy, 95% of them on maintenance therapy with aspirin plus clopidogrel. Timing of the surgery was at the discretion of the surgeons. Treating physicians were blinded to LTA results. The mean preoperative washout period for dual antiplatelet therapy was 1.5 days. Patients had vascular (76%), orthopedic (10%), abdominal (7%), or other (7%) surgery.

The ongoing study might help define a "bleeding cutoff" measure by LTA to better individualize the timing of surgery, Dr. Wolfgang Toller and his colleagues said in a poster session at the annual meeting of the American Society of Anesthesiologists.

In general, approximately 5% of patients in their first year of dual antiplatelet therapy undergo noncardiac surgery, which creates a conundrum for management. Discontinuing dual antiplatelet therapy before noncardiac surgery has been associated with a 20% risk of major adverse cardiac events, but there’s a 20%-40% risk of moderate to severe bleeding if dual antiplatelet therapy is continued during noncardiac surgery, said Dr. Toller of the Medical University of Graz, Austria.

The 147 patients in the study underwent vascular surgery (76%), orthopedic surgery (10%), abdominal surgery (7%), or other surgical procedures (7%). All had been on P2Y12 receptor inhibitors within 7 days before surgery.

Investigators used the Chronolog 700 Lumi-Aggregometer to assess platelet aggregation in preoperative blood, using 5 mcm of adenosine diphosphate as the specific inductor for platelet aggregation.

Overall, they found an average 40% maximum change in light transmission from baseline after adding the adenosine diphosphate to blood samples. In patients with increased bleeding, however, the mean maximum change in light transmission was approximately 30% (suggesting less platelet aggregation), compared with a more than 40% change in patients who bled less from the surgery.

Dr. Toller reported having no financial disclosures.

Surgery adds risk of perioperative bleeding

Dr. Lary Robinson, FCCP, comments: The vast majority of patients on dual platelet therapy (aspirin plus another agent such as clopidogrel) have had implantation of a drug-eluting coronary stent, who need to remain on this regimen for 1 year, after which it may be safely reduced to aspirin alone in most cases. In this first year, urgent surgery, such as that needed for cancer, as well as vascular surgery for ischemia or trauma, comes with the added risk of significant perioperative bleeding.

Anesthesiologists Wolfgang Toller and associates describe using the in vitro platelet function test, called light transmission aggregometry, in 147 patients. When used just prior to surgery, the test was somewhat predictive of which patients were at elevated bleeding risk. They propose that this test may better define and individualize the timing of surgery. However, the differences in test results are small and recommendations are not yet definite. Nevertheless, refinements in testing may lead to more specific recommendations about which patients should have surgery postponed due to a much greater bleeding risk.

sboschert@frontlinemedcom.com

SAN FRANCISCO – Preoperative light transmission aggregometry assessments of platelet aggregation may help identify which patients on dual antiplatelet therapy are at greater risk of sustained bleeding from noncardiac surgery, a prospective study of 147 consecutive patients suggests.

The light transmission aggregometry (LTA) assessments of blood drawn immediately before noncardiac surgery were significantly lower in the 32% of patients with sustained bleeding than in the other patients.

All patients were on dual antiplatelet therapy, 95% of them on maintenance therapy with aspirin plus clopidogrel. Timing of the surgery was at the discretion of the surgeons. Treating physicians were blinded to LTA results. The mean preoperative washout period for dual antiplatelet therapy was 1.5 days. Patients had vascular (76%), orthopedic (10%), abdominal (7%), or other (7%) surgery.

The ongoing study might help define a "bleeding cutoff" measure by LTA to better individualize the timing of surgery, Dr. Wolfgang Toller and his colleagues said in a poster session at the annual meeting of the American Society of Anesthesiologists.

In general, approximately 5% of patients in their first year of dual antiplatelet therapy undergo noncardiac surgery, which creates a conundrum for management. Discontinuing dual antiplatelet therapy before noncardiac surgery has been associated with a 20% risk of major adverse cardiac events, but there’s a 20%-40% risk of moderate to severe bleeding if dual antiplatelet therapy is continued during noncardiac surgery, said Dr. Toller of the Medical University of Graz, Austria.

The 147 patients in the study underwent vascular surgery (76%), orthopedic surgery (10%), abdominal surgery (7%), or other surgical procedures (7%). All had been on P2Y12 receptor inhibitors within 7 days before surgery.

Investigators used the Chronolog 700 Lumi-Aggregometer to assess platelet aggregation in preoperative blood, using 5 mcm of adenosine diphosphate as the specific inductor for platelet aggregation.

Overall, they found an average 40% maximum change in light transmission from baseline after adding the adenosine diphosphate to blood samples. In patients with increased bleeding, however, the mean maximum change in light transmission was approximately 30% (suggesting less platelet aggregation), compared with a more than 40% change in patients who bled less from the surgery.

Dr. Toller reported having no financial disclosures.

Surgery adds risk of perioperative bleeding

Dr. Lary Robinson, FCCP, comments: The vast majority of patients on dual platelet therapy (aspirin plus another agent such as clopidogrel) have had implantation of a drug-eluting coronary stent, who need to remain on this regimen for 1 year, after which it may be safely reduced to aspirin alone in most cases. In this first year, urgent surgery, such as that needed for cancer, as well as vascular surgery for ischemia or trauma, comes with the added risk of significant perioperative bleeding.

Anesthesiologists Wolfgang Toller and associates describe using the in vitro platelet function test, called light transmission aggregometry, in 147 patients. When used just prior to surgery, the test was somewhat predictive of which patients were at elevated bleeding risk. They propose that this test may better define and individualize the timing of surgery. However, the differences in test results are small and recommendations are not yet definite. Nevertheless, refinements in testing may lead to more specific recommendations about which patients should have surgery postponed due to a much greater bleeding risk.

sboschert@frontlinemedcom.com

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Platelet inhibition test helps predict surgical bleeding
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Platelet inhibition test helps predict surgical bleeding
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Preoperative light transmission, platelet aggregation, antiplatelet therapy, noncardiac surgery, LTA, clopidogrel,
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Major finding: The mean maximum change in light transmission on LTA assessment of preoperative blood was approximately 30% in patients with increased bleeding from surgery, significantly lower than the more than 40% change in those who bled less.

Data source: Prospective study of 147 patients on dual antiplatelet therapy who underwent noncardiac surgery at one institution.

Disclosures: Dr. Toller reported having no financial disclosures.