Professor - University Medical Line, Anesthesiology, Perioperative and Pain Medicine
Member, Cardiovascular Institute
- Independent Studies (5)
P-Wave Characteristics on Routine Preoperative Electrocardiogram Improve Prediction of New-Onset Postoperative Atrial Fibrillation in Cardiac Surgery
JOURNAL OF CARDIOTHORACIC AND VASCULAR ANESTHESIA
2014; 28 (6): 1497-1504
To test the hypothesis that including preoperative electrocardiogram (ECG) characteristics with clinical variables significantly improves the new-onset postoperative atrial fibrillation prediction model.Retrospective analysis.Single-center university hospital.Five hundred twenty-six patients,≥18 years of age, who underwent coronary artery bypass grafting, aortic valve replacement, mitral valve replacement/repair, or a combination of valve surgery and coronary artery bypass grafting requiring cardiopulmonary bypass.Retrospective review of medical records.Baseline characteristics and cardiopulmonary bypass times were collected. Digitally-measured timing and voltages from preoperative electrocardiograms were extracted. Postoperative atrial fibrillation was defined as atrial fibrillation requiring therapeutic intervention. Two hundred eight (39.5%) patients developed postoperative atrial fibrillation. Clinical predictors were age, ejection fraction<55%, history of atrial fibrillation, history of cerebral vascular event, and valvular surgery. Three ECG parameters associated with postoperative atrial fibrillation were observed: Premature atrial contraction, p-wave index, and p-frontal axis. Adding electrocardiogram variables to the prediction model with only clinical predictors significantly improved the area under the receiver operating characteristic curve, from 0.71 to 0.78 (p<0.01). Overall net reclassification improvement was 0.059 (p = 0.09). Among those who developed postoperative atrial fibrillation, the net reclassification improvement was 0.063 (p = 0.03).Several p-wave characteristics are independently associated with postoperative atrial fibrillation. Addition of these parameters improves the postoperative atrial fibrillation prediction model.
View details for DOI 10.1053/j.jvca.2014.04.034
View details for PubMedID 25263779
Factor VIII Inhibitor Bypass Activity and Recombinant Activated Factor VII in Cardiac Surgery
JOURNAL OF CARDIOTHORACIC AND VASCULAR ANESTHESIA
2014; 28 (5): 1221-1226
Postcardiopulmonary bypass hemorrhage remains a serious complication of cardiac surgery. Given concerns regarding adverse effects of blood product transfusion and limited efficacy of current antifibrinolytics, procoagulant medications, including recombinant factor VIIa (rFVIIa) and factor eight inhibitor bypass activity (FEIBA), increasingly have been used in managing refractory bleeding. While effective, these medications are associated with thromboembolic complications. This study compared the efficacy and risk of adverse events of rFVIIa and FEIBA in cardiac surgical patients with refractory bleeding.This retrospective study evaluated 168 patients who underwent cardiac surgery and received either FEIBA or rFVIIa to manage postbypass hemorrhage. Demographic, clinical, and outcomes data were collected and statistical analysis performed to compare thromboembolic event rates, relative efficacy, and 30-day mortality following administration of these medications.Single university hospital.Patients undergoing cardiac surgery.None.Sixty-one patients received rFVIIa, and 107 received FEIBA. Demographics, surgical procedures, and preoperative anticoagulation were similar between the cohorts; however, the rFVIIa cohort had longer durations of cardiopulmonary bypass (305.1 v 243.8 min, p<0.01). There were no significant differences in the number of thromboembolic events, 30-day mortality, or rates of revision surgery. Neither group demonstrated a clear relationship between dosage and occurrence of thromboembolic events. The rFVIIa cohort received more platelets than the FEIBA cohort (3.13 v 1.67 units, p = 0.01), but transfusion rates of other blood products were similar.This study suggests that rFVIIa and FEIBA have similar efficacy and adverse event profiles in managing intractable postbypass hemorrhage in cardiac surgical patients. Further prospective studies are required.
View details for DOI 10.1053/j.jvca.2014.04.015
View details for Web of Science ID 000343188500009
Trends in acute kidney injury, associated use of dialysis, and mortality after cardiac surgery, 1999 to 2008.
Annals of thoracic surgery
2013; 95 (1): 20-28
The development of acute kidney injury (AKI) after cardiac surgery is associated with significant mortality, morbidity, and cost. The last decade has seen major changes in the complexity of cardiac surgical candidates and in the number and type of cardiac surgical procedures being performed.Using data from the Nationwide Inpatient Sample, we determined the annual rates of AKI, AKI requiring dialysis (AKI-D), and inpatient mortality after cardiac surgery in the United States in the years 1999 through 2008.Inpatient mortality with AKI and AKI-D decreased from 27.9% and 45.9%, respectively, in 1999 to 12.8% and 35.3%, respectively, in 2008. Compared with 1999, the odds of AKI and AKI-D in 2008, adjusted for demographic and clinical factors, were 3.30 (95% confidence interval [CI]: 2.89 to 3.77) and 2.23 (95% CI: 1.78 to 2.80), respectively. Corresponding adjusted odds of death associated with AKI and AKI-D were 0.31 (95% CI: 0.26 to 0.36) and 0.47 (95% CI: 0.34 to 0.65.) Taken together, the attributable risks for death after cardiac surgery associated with AKI and AKI-D increased from 30% and 5%, respectively, in 1999 to 47% and 14%, respectively, in 2008.In sum, despite improvements in individual patient outcomes over the decade 1999 to 2008, the population contribution of AKI and AKI-D to inpatient mortality after surgery increased over the same period.
View details for DOI 10.1016/j.athoracsur.2012.05.131
View details for PubMedID 23272825
Case report: a thrombus in the venous reservoir while using bivalirudin in a patient with heparin-induced thrombocytopenia undergoing heart transplantation.
Anesthesia and analgesia
2010; 111 (3): 609-612
Direct thrombin inhibitors are heparin alternatives for anticoagulation during cardiopulmonary bypass in patients with heparin-induced thrombocytopenia. We report a case of a large thrombus forming in the venous reservoir while using bivalirudin. We suggest that blood stasis associated with the full venous reservoir maintained in this case led to formation of a large thrombus at the top of the venous canister. Furthermore, activated clotting times may not accurately reflect the magnitude of anticoagulation when using direct thrombin inhibitors.
View details for DOI 10.1213/ANE.0b013e3181e9ead3
View details for PubMedID 20686010
Predictive value of the National Institutes of Health Stroke Scale and the Mini-Mental State Examination for neurologic outcome after coronary artery bypass graft surgery
JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY
2010; 139 (4): 901-912
We intended to define the role of the National Institutes of Health Stroke Scale and the Mini-Mental State Examination in identifying adverse neurologic outcomes in a large international sample of patients undergoing cardiac surgery.We evaluated 4707 patients undergoing cardiac surgery with cardiopulmonary bypass at 72 centers in 17 countries between November 1996 and June 2000. Prespecified overt neurologic outcomes were categorized as type I (clinically diagnosed stroke, transient ischemic attack, encephalopathy, or coma) or type II (deterioration of intellectual function). The National Institutes of Health Stroke Scale and Mini-Mental State Examination were administered preoperatively and on postoperative day 3, 4, or 5. Receiver operating characteristic curves were plotted to determine the predictive value of worsening in National Institutes of Health Stroke Scale and Mini-Mental State Examination scores with respect to type I and II outcomes.The receiver operating characteristic area under the curve for changes in National Institutes of Health Stroke Scale score (n = 4620) was 0.89 for type I outcomes and 0.66 for type II outcomes. A 1-point worsening in National Institutes of Health Stroke Scale score provided excellent discrimination (86% specificity; 84% sensitivity) of type I outcomes. The receiver operating characteristic area under the curve for changes in Mini-Mental State Examination score (n = 4707) was 0.75 for type I outcomes and 0.71 for type II outcomes. A 2-point worsening in Mini-Mental State Examination score provided only fair discrimination (73% specificity; 62% sensitivity) of type II outcomes.We used baseline controls and postoperative worsening in National Institutes of Health Stroke Scale and Mini-Mental State Examination scores to predict both serious adverse neurologic outcome and deterioration of intellectual function. Our findings provide the only reference for evaluating these tests that are used in cardiac surgical clinical trials.
View details for DOI 10.1016/j.jtcvs.2009.07.055
View details for Web of Science ID 000275815000014
View details for PubMedID 19744674
Aprotinin, blood loss, and renal dysfunction in deep hypothermic circulatory arrest
2001; 104 (12): I276-I281
The technique of deep hypothermic circulatory arrest (DHCA) for cardiothoracic surgery is associated with increased risk for perioperative blood loss and renal dysfunction. Although aprotinin, a serine protease inhibitor, reduces blood loss in patients undergoing cardiopulmonary bypass, its use has been limited in the setting of DHCA because of concerns regarding aprotinin-induced renal dysfunction. Therefore, we assessed the affect of aprotinin on both blood transfusion requirements and renal function in patients undergoing cardiovascular surgery and DHCA.We reviewed the records of 853 patients who underwent aortic or thoracoabdominal surgery at Stanford University Medical Center between January 1992 and March 2000. Two hundred three of these patients were treated with DHCA, and 90% (183) survived for more than 24 hours. Preoperative patient characteristics and intraoperative and postoperative clinical and surgical variables were recorded, and creatinine clearance (CRCl) was calculated for the preoperative and postoperative periods; renal dysfunction was prospectively defined as a 25% reduction in CRCl. The association between perioperative variables, including aprotinin use, and renal dysfunction was assessed by ANOVA techniques. Total urine output was 1294+/-1024 mL and 3492+/-1613 mL during and after surgery, respectively. CRCl decreased significantly after DHCA from 86+/-8 mL/min (before surgery) to 67+/-4 mL/min (in the intensive care unit) (P<0.01). Thirty-eight percent of patients (70 of 183) had postoperative renal dysfunction. Multivariate regression analyses identified 5 factors independently associated with a >25% reduction in CRCl: requirement for >/=5 U of packed red blood cells(P=0.0002; OR=2.1), =800 mL of urine collected in the operating room (P=0.0011; OR=1.9), nonuse of dopamine (P=0.0430; OR=1.6), hematocrit =21 mg% (P=0.0343; OR=1.5), and =2100 mL of urine during the first 24 hours in the intensive care unit (P=0.0039; OR=2.0). Aprotinin did not increase the likelihood of postoperative renal dysfunction (P=0.951), nor did it significantly reduce packed red blood cell transfusion requirements in either primary (n=107) (P=0.456) or reoperative cardiovascular (n=76) (P=0.176) procedures. During the operative period, the aprotinin group received a greater number of units of platelets (10.0 versus 6.6 U, P<0.012), fresh frozen plasma (4.8 versus 3.1 U, P<0.03), and cryoprecipitate (9.9 versus 5.4 U, P<0.002) than patients not prescribed aprotinin. Similarly, patients given aprotinin received more cryoprecipitate in the intensive care unit (7.3 versus 3.0 U, P<0.024).These data suggest that the administration of aprotinin to patients treated with DHCA does not increase the risk of renal dysfunction. However, aprotinin may not ameliorate the problem of perioperative blood loss in DHCA. Patients with greater requirements for packed red blood cell transfusions or reduced urine production are more likely to have postoperative renal dysfunction. Dopamine may provide renal protection in the setting of DHCA.
View details for PubMedID 11568069
Multicenter preoperative stroke risk index for patients undergoing coronary artery bypass graft surgery
1996; 94 (9): 74-80
View details for Web of Science ID A1996VP69000014