Biomedical subjects

P Treanor

Publications and source records attributed to P Treanor.

10 recordsLinked to original sources

PubMed1998

Effect of anticoagulation protocol on outcome in patients undergoing CABG with heparin-bonded cardiopulmonary bypass circuits.

BACKGROUND: We have demonstrated that the use of heparin-bonded cardiopulmonary bypass circuits (HBCs) combined with a lower anticoagulation protocol as an adjunct to an integrated blood conservation strategy decreases the incidence and magnitude of homologous transfusion and improves clinical outcome in patients undergoing primary coronary artery bypass grafting. It is not known whether it is the lower anticoagulation protocol that influences outcome in patients treated with HBCs. Furthermore, the thrombogenic risk of using lower anticoagulation with HBCs still is debated. METHODS: To answer these questions, a prospective randomized study was conducted in which 244 patients undergoing primary coronary artery bypass grafting were treated with HBCs and randomized to undergo either a full (activated clotting time, > 450 seconds) or a lower (activated clotting time, > 250 seconds) anticoagulation protocol. In addition to clinical outcome, levels of thrombin generation markers during and after cardiopulmonary bypass were assessed in a consecutive subset of 58 patients (full anticoagulation profile = 28, lower anticoagulation profile = 30) by measuring thrombin-antithrombin complexes and prothrombin fragment 1.2. Levels of these markers also were correlated with the activated clotting time during cardiopulmonary bypass. RESULTS: Preoperative and intraoperative risk profiles and other characteristics were similar in both groups, with more than 60% of patients undergoing nonelective operation. Compared with the full anticoagulation protocol group, patients in the lower anticoagulation protocol group were less likely to require blood products (24.2% versus 35.8%, respectively; p = 0.047) and received substantially fewer homologous donor units (0.50 +/- 0.92 versus 1.08 +/- 2.10 U, respectively; p = 0.005). Clinical outcomes were uniformly outstanding (but similar) in both treatment groups, with a modest reduction in the length of the hospital stay in the lower anticoagulation protocol group (5.26 +/- 1.23 versus 5.63 +/- 1.73 days, respectively; p = 0.05). The use of HBCs with a lower anticoagulation protocol was not associated with any adverse clinical events. Thrombin generation increased during cardiopulmonary bypass in both treatment groups, but was unrelated to the anticoagulation protocol or the activated clotting time (r2 = 0.03). No differences between the full and lower anticoagulation protocol groups were noted in the number of microemboli detected by transcranial Doppler analyses during cardiopulmonary bypass (n = 40) or in the postoperative neurologic and neuropsychologic outcomes (n = 30). CONCLUSIONS: This study definitively demonstrates that, when used appropriately, patients who are treated with HBCs and a lower anticoagulation protocol have a lower incidence and magnitude of homologous transfusion and are not at any added risk for clinical, hematologic (thrombin-antithrombin complex and fragment 1.2 measurements), or microscopic (transcranial Doppler analyses) thromboembolic complications or for neurologic or neuropsychologic deficits.

Aged↗

PubMed1997

Heparin-bonded circuits decrease myocardial ischemic damage: an experimental study.

BACKGROUND: Heparin-bonded cardiopulmonary bypass circuits reduce complement activation, but their effect on myocardial function is unknown. This study was undertaken to determine whether heparin-bonded circuits reduce myocardial damage during acute surgical revascularization. METHODS: In 16 pigs, the second and third diagonal vessels were occluded with snares for 90 minutes followed by 45 minutes of cardioplegic arrest and 180 minutes of reperfusion with the snares released. During the period of coronary occlusion, all animals were placed on percutaneous bypass followed by standard cardiopulmonary bypass during the periods of cardioplegic arrest and reperfusion. In 8 pigs, heparin-bonded circuits were used, whereas 8 other pigs received nonbonded circuits. RESULTS: Animals treated with heparin-bonded circuits had the best preservation of wall motion scores (3.5 +/- 0.3 versus 2.3 +/- 0.2; 4 = normal to -1 = dyskinesis; p < 0.05), least tissue acidosis (change in pH = -0.31 +/- 0.02 versus -0.64 +/- 0.08; p < 0.05), smallest increase in lung H2O (1.7% +/- 0.7% versus 6.1% +/- .5%; p < 0.05), and the lowest area of necrosis/area of risk (20.3% +/- 2.2% versus 40.4% +/- 1.6%; p < 0.05). CONCLUSIONS: We conclude that heparin-bonded circuits significantly decrease myocardial ischemic damage during acute surgical revascularization.

Acid-Base Equilibrium↗

PubMed1996

Heparin-bonded circuits with a reduced anticoagulation protocol in primary CABG: a prospective, randomized study.

BACKGROUND: A substantial proportion of patients undergoing primary coronary revascularization require homologous transfusions. To address this problem, a comprehensive strategy to diminish perioperative blood loss was developed. METHODS: A prospective randomized trial was undertaken to test the hypothesis that "tip-to-tip" heparin-bonded cardiopulmonary bypass circuits (HBC) can further enhance blood conservation and clinical outcomes in patients undergoing primary coronary artery bypass grafting. Two hundred thirty-four patients were treated with either HBC and lower anticoagulation therapy (activated clotting time > 280 seconds) or with conventional, nonheparin-bonded circuits and full anticoagulation therapy (activated clotting time > 480 seconds). RESULTS: Preoperative and intraoperative risk profiles and characteristics were similar in both groups, with 69.7% of the patients undergoing nonelective coronary artery bypass grafting. Compared with the group with nonheparin-bonded circuits, patients treated with HBC had a lower chest tube output in the first 24 hours (561 +/- 257 versus 651 +/- 403; p = 0.04), were less likely to receive blood products (31.6% versus 47.9%; p = 0.01), and required substantially fewer homologous donor units (1.98 +/- 4.8 versus 4.29 +/- 10.1; p = 0.029). Patients treated with HBC required a shorter duration of ventilatory support (13.2 +/- 16.9 versus 23.4 +/- 50.0 hours; p = 0.04), spent less time in the surgical intensive care unit (20.7 +/- 17.4 versus 35.5 +/- 61.7 hours; p = 0.01), spent fewer days in the hospital (6.0 +/- 2.5 versus 7.3 +/- 5.2 days; p = 0.02), and had fewer postoperative complications (25.6% versus 39.3%; p = 0.03). The use of HBC with a lower anticoagulation protocol was not associated with any adverse events. CONCLUSIONS: This study demonstrates that the use of HBC with a lower anticoagulation protocol in primary coronary artery bypass grafting safely and effectively reduces the incidence and magnitude of homologous transfusion, the duration of ventilation, and surgical intensive care unit and hospital stays.

Aged↗

PubMed1995

Combining percutaneous bypass with coronary retroperfusion limits myocardial necrosis.

After an acute coronary occlusion that results in hemodynamic instability, the institution of percutaneous bypass (PB) can effectively support the failing myocardium. However, PB cannot augment coronary blood flow, and substantial regional myocardial necrosis can still occur. This experimental study was undertaken to determine whether combining PB with coronary venous retroperfusion using pressure-controlled intermittent coronary sinus occlusion (PICSO) would limit myocardial necrosis after an acute coronary occlusion. In 30 pigs, the second and third diagonal vessels were occluded with snares for 90 minutes followed by 30 minutes of cardioplegic arrest and 180 minutes of reperfusion with the snares released. During the period of coronary occlusion, 10 pigs were placed on PB, 10 pigs received PB+PICSO, and 10 pigs received no support (unmodified). Hearts treated with the combination of PB+PICSO had the highest wall motion scores (unmodified, 1.4 +/- 0.3; PB, 1.4 +/- 0.3; PB+PICSO, 2.8 +/- 0.3 [p < 0.05 versus unmodified and PB]) and the lowest area of necrosis in the area at risk (unmodified, 73% +/- 3%; PB, 43% +/- 2%; PB+PICSO, 14% +/- 2% [p < 0.05, PB and PB+PICSO versus unmodified; p < 0.05, PB+PICSO versus PB]). We conclude that combining PB with coronary venous retroperfusion significantly limits myocardial necrosis.

Animals↗

PubMed1995

Role of leukocyte depletion during cardiopulmonary bypass and cardioplegic arrest.

BACKGROUND: Leukocyte depletion (LD) has been shown to be beneficial during the reperfusion of acutely ischemic myocardium; however, its role during cardiopulmonary bypass (CPB) in hearts protected with blood cardioplegia (BCP) is unknown. This experimental study sought to determine whether LD filters inserted in the CPB circuit before cardioplegic arrest and in the BCP circuit during arrest would decrease ischemic myocardial damage. METHODS: In 20 pigs, the second and third diagonal vessels were occluded for 90 minutes, followed by 45 minutes of BCP arrest and 180 minutes of reperfusion on CPB. In 5 pigs, LD filters were inserted in both the CPB and BCP circuits (LD-CPB+BCP). Five pigs had LD during BCP (LD-BCP), 5 pigs had LD during CPB (LD-CPB), and 5 pigs had no LD. Ischemic damage was assessed by wall motion scores using two-dimensional echocardiography and the area of necrosis/area of risk. RESULTS: The LD-CPB and LD-CPB+BCP groups had the highest wall motion scores and the lowest area of necrosis/area of risk. The addition of LD to BCP alone did not significantly alter wall motion scores or the area of necrosis/area of risk. CONCLUSION: Leukocyte depletion filters significantly reduce ischemic damage during acute surgical revascularization and appear to be most effective when placed in the CPB circuit before cardioplegic arrest.

Animals↗

PubMed1994

Enhanced recovery of ischemic myocardium by combining percutaneous bypass with intraaortic balloon pump support.

Although percutaneous bypass (PB) can support the failing myocardium, regional ischemic damage may still occur beyond a coronary occlusion. This study sought to determine whether the addition of intraaortic balloon pump (IABP) support to PB would result in more optimal salvage of ischemic myocardium. In 30 pigs, the second and third diagonal vessels were occluded with snares for 90 minutes followed by 30 minutes of cardioplegic arrest and 3 hours of reperfusion with the snares released. During the period of coronary artery occlusion, 10 pigs were placed on PB, 10 pigs received PB plus IABP support, and 10 pigs received no support (the unmodified group). The hearts treated with the combination of PB and IABP support exhibited the highest wall motion scores (3.3 +/- 0.20 for the PB plus IABP group [p < 0.05 from the unmodified group and from the PB group]; versus 1.40 +/- 0.30 for the PB group versus 1.37 +/- 0.33 for the unmodified group), the least tissue acidosis (change in pH, -0.30 +/- 0.2 for the PB plus IABP group [p < 0.05 from the PB group] versus -0.60 +/- 0.10 for the PB group versus -0.41 +/- 0.13 for the unmodified group), and the least area of necrosis (25% +/- 5% for the PB plus IABP group [p < 0.05 from the unmodified group and from the PB group]; versus 43% +/- 2% for the PB group [p < 0.05 from the unmodified group] versus 73% +/- 3% for the unmodified group).(ABSTRACT TRUNCATED AT 250 WORDS)

Acidosis↗

PubMed1993

Warm versus cold blood cardioplegia--is there a difference?

This experimental study sought to compare the effectiveness of warm blood cardioplegia versus cold blood cardioplegia in protecting areas of ischemic myocardium during urgent coronary revascularization. In 40 adult pigs, the second and third diagonal vessels were occluded with snares for 90 minutes. All animals were then placed on cardiopulmonary bypass and underwent 45 minutes of cardioplegic arrest followed by 3 hours of reperfusion during which time the coronary snares were released. During the period of cardioplegic arrest, 10 pigs received antegrade continuous warm blood cardioplegic solution (37 degrees C) at 100 ml/min; 10 animals received retrograde warm blood cardioplegic solution at 100 ml/min; 10 received intermittent, antegrade cold blood cardioplegic solution (4 degrees C), and 10 animals received intermittent, antegrade/retrograde cold blood cardioplegic solution. Hearts protected with antegrade warm blood cardioplegic solution had the lowest pH values in the area at risk (6.59 +/- 0.10 antegrade warm blood cardioplegia versus 6.80 +/- 0.10 retrograde warm blood cardioplegia versus 6.72 +/- 0.18 antegrade cold blood cardioplegia versus 6.85 +/- 0.15 antegrade/retrograde cold blood cardioplegia and the highest area of necrosis (42% +/- 3% antegrade warm blood cardioplegia versus 26% +/- 2% [p < 0.05 from antegrade warm blood cardioplegia] retrograde warm blood cardioplegia versus 31% +/- 2% [p < 0.05 from antegrade warm blood cardioplegia] antegrade cold blood cardioplegia versus 21% +/- 2% [p < 0.05 from antegrade warm blood cardioplegia] antegrade/retrograde cold blood cardioplegia). We conclude that in the presence of an acute coronary occlusion with ischemic myocardium, warm blood cardioplegic solution should be given in a continuous retrograde fashion and does not result in myocardial protection superior to the protection that can be achieved with antegrade/retrograde cold blood cardioplegic solution.

Animals↗

PubMed1991

Role of percutaneous bypass in reducing infarct size after revascularization for acute coronary insufficiency.

This study compares the effectiveness of percutaneous bypass (PB) with that of the intra-aortic balloon pump (IABP) in reducing infarct size and ischemic damage after revascularization for acute coronary occlusion. In 30 adult pigs, the second and third diagonal vessels were occluded with snares for 1 1/2 hours, followed by 1/2 hour of cardioplegic arrest and 3 hours of reperfusion with the snares released. During the period of coronary occlusion before the institution of cardiopulmonary bypass, 10 pigs were placed on PB, 10 pigs received IABP, and 10 others received no intervention (unmodified). Ischemic damage in the area at risk was assessed by echo wall motion scores (ranging from 4 indicating normal to -1 indicating dyskinesia), changes in myocardial tissue pH (delta pH) from preischemia, and the area of necrosis/area of risk (AN/AR) ratio. Hearts treated with the IABP had the highest wall motion scores (1.27 +/- 0.33 for unmodified versus 1.40 +/- 0.30 for PB versus 2.04 +/- 0.30 for IABP), the least change in pH values from preischemia (delta pH: 0.41 +/- 0.13 for unmodified versus 0.60 +/- 0.10 for PB versus 0.25 +/- 0.09 for IABP, p less than 0.05 for IABP versus PB), and the least amount of myocardial necrosis (AN/AR ratio: 73 +/- 4% for unmodified versus 43 +/- 2 for PB versus 27 +/- 4 for IABP, p less than 0.05 for PB and IABP versus unmodified and for IABP versus PB). Although the PB group experienced less myocardial necrosis than did the unmodified group, the most optimal recovery occurred in the IABP group.

Angioplasty, Balloon, Coronary↗

PubMedDate not supplied

Heparin-bonded circuits improve clinical outcomes in emergency coronary artery bypass grafting.

Compared to patients undergoing elective or urgent coronary artery bypass grafting (CABG), those undergoing emergency CABG (EM-CABG) have a higher morbidity and mortality. The use of heparin-bonded circuits (HBC) has been shown to improve clinical outcomes in nonemergent CABG patients. It is not known, however, whether the improved hemostasis and attenuation of the inflammatory response to cardiopulmonary bypass, conferred by HBC, can overcome the high incidence of comorbid risk factors in (EM-CABG) patients and improve their outcomes. A retrospective analysis of 206 consecutive patients undergoing EM-CABG over 4 years (1993-1997) at one institution was performed. Eighty-one patients were treated with conventional non-heparin-bonded circuits (NHBC) with full anticoagulation protocol (FAP, activated clotting time [ACT] > 480 sec); 125 patients were treated with HBC and a lower anticoagulation protocol (LAP, ACT > 280 seconds). Outcomes and results were collected prospectively and are presented as mean +/- SD. Preoperative risk profiles were similar in both treatment groups. Postoperatively, compared with the NHBC group, patients treated with HBC/LAP required fewer homologous donor units (4.1 +/- 10.7 vs 8.2 +/- 13.6 units, p = 0.005), were less likely to require inotropic support (18.6% vs 38.3%, p = 0.005), and had a lower incidence of perioperative myocardial infarction (MI, 3.2% vs 12.3%, p = 0.04) and pulmonary complications (4.0% vs 12.3%, p = 0.04). The use of HBC/LAP resulted in a decreased incidence of postoperative complications (12.8% vs 28.4%, p = 0.01, odds ratio 0.37 with 95% confidence interval [CI] 0.18-0.76). This resulted in a shorter duration of ventilatory support (30.5 +/- 54.0 vs 72.8 +/- 16.7 hours, p = 0.009), ICU stay (38.2 +/- 36.5 vs 91.5 +/- 68.7 hours, p = 0.009), hospital stay (8.0 +/- 7.1 vs 11.0 +/- 8.9 days, p = 0.008), and therefore cost. In conclusion, the use of HBC/LAP in EM-CABG resulted in a reduction of homologous transfusion and postoperative complications associated with decreased hospital stays and cost.

Aged↗

PubMedDate not supplied

Retroperfusion and balloon support to improve coronary revascularization.

Coronary venous retroperfusion and Intra-Aortic Balloon Pump (IABP) support are methods currently utilized to reduce ischemic damage prior to revascularization of acutely ischemic myocardium. This study was undertaken to determine whether combining coronary venous retroperfusion using Pressure Controlled Intermittent Coronary Sinus Occlusion (PICSO) with the IABP would result in improved salvage of ischemic myocardium. In 40 adult pigs, the second and third diagonal vessels were occluded with snares for 1 1/2 hours followed by 1/2 hours of cardioplegic arrest and 3 hours of reperfusion with the snares released. During the period of coronary occlusion prior to arrest, 10 pigs received the IABP, 10 had PICSO, 10 had PICSO+IABP, while 10 had no intervention (Unmodified). Ischemic damage was assessed by echocardiographic wall motion scores, myocardial pH, and the area of necrosis/area of risk using histochemical staining. Both PICSO and the IABP alone significantly reduced ischemic damage. However, the best wall motion scores, highest pH, and least necrosis was seen in the IABP+PICSO group. We conclude that the combination of coronary venous retroperfusion using PICSO and the IABP results in the most optimal recovery of acutely ischemic myocardium during emergent surgical revascularization.

Animals↗