Karla G Christian
Research interests
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InterestsCardiac Surgery, Congenital Heart Disease
Publications
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2.38Impact points
Angiotensin-converting enzyme inhibition alters the inflammatory and fibrinolytic response to cardiopulmonary bypass in children.
Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies. 10/2010; 12(5):532-8.
Many children with a congenital heart defect undergo surgical correction requiring cardiopulmonary bypass. One-sixth of these patients take an angiotensin-converting enzyme inhibitor for heart failure treatment. The effect of angiotensin-converting enzyme inhibition on the fibrinolytic and inflammat... [more] Many children with a congenital heart defect undergo surgical correction requiring cardiopulmonary bypass. One-sixth of these patients take an angiotensin-converting enzyme inhibitor for heart failure treatment. The effect of angiotensin-converting enzyme inhibition on the fibrinolytic and inflammatory response in children undergoing cardiopulmonary bypass is unknown. In adults, angiotensin-converting enzyme inhibition attenuates the increase in plasminogen activator inhibitor-1 after cardiopulmonary bypass, whereas the effect on the interleukin-6 response is uncertain. This study tests the hypothesis that preoperative angiotensin-converting enzyme inhibition attenuates postoperative plasminogen activator inhibitor-1 and interleukin-6 expression after cardiopulmonary bypass in children. Single-center prospective, randomized, nonblinded study. University-affiliated pediatric hospital. Children undergoing elective surgical correction of a congenital heart defect requiring cardiopulmonary bypass and taking an angiotensin-converting enzyme inhibitor. Children were randomized to continue angiotensin-converting enzyme inhibitor until the morning of surgery (angiotensin-converting enzyme inhibitor group, n = 11) or to discontinue therapy 72 hrs before surgery (no angiotensin-converting enzyme inhibitor group, n = 9). Blood samples were collected at baseline before cardiopulmonary bypass, at 30 mins of cardiopulmonary bypass, on arrival to the intensive care unit, and on postoperative day 1. Baseline bradykinin concentrations were significantly higher and angiotensin-converting enzyme activity significantly lower in the angiotensin-converting enzyme inhibitor group compared with the no angiotensin-converting enzyme inhibitor group (p = .04 and .001, respectively). Plasminogen activator inhibitor-1 antigen increased 15-fold after cardiopulmonary bypass and peaked on postoperative day 1 (from 4.6 ± 1.2 to 67.7 ± 9.5 ng/mL; p < .001). Postoperative day 1 plasminogen activator inhibitor-1 antigen correlated significantly with cardiopulmonary bypass time (r2 = 0.40, p = .03) and was significantly lower in the angiotensin-converting enzyme inhibitor group compared with the no angiotensin-converting enzyme inhibitor group (p = .03). The proinflammatory markers interleukin-6 and interleukin-8 as well as the anti-inflammatory marker interleukin-10 increased significantly after cardiopulmonary bypass (all p < .001). Interleukin-6 concentrations were significantly higher in the angiotensin-converting enzyme inhibitor group after cardiopulmonary bypass (p = .02) even after controlling for potential confounding factors such as age, cardiopulmonary bypass time, and transfusion volume. Angiotensin-converting enzyme inhibition attenuates the increase in postoperative plasminogen activator inhibitor-1 but enhances the interleukin-6 response in children undergoing cardiopulmonary bypass.
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1.15Impact points
Congenitally Corrected Transposition of the Great Arteries: A Unique Case from Iraq.
Pediatric cardiology. 09/2009;
A severely cyanotic 27-month-old Iraqi child was transferred to the United States for surgical treatment of suspected tetralogy of Fallot. Her diagnostic studies showed dextrocardia, congenitally corrected transposition of the great arteries, hypoplastic left-sided ventricle, interrupted inferior ve... [more] A severely cyanotic 27-month-old Iraqi child was transferred to the United States for surgical treatment of suspected tetralogy of Fallot. Her diagnostic studies showed dextrocardia, congenitally corrected transposition of the great arteries, hypoplastic left-sided ventricle, interrupted inferior vena cava, and severe pulmonic stenosis. Given the anatomic constraints as well as the absence of long-term medical care, the decision was made to pursue single-ventricle palliation. The patient recovered from a superior cavopulmonary anastomosis without event and has since returned to her native Iraq.
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1.15Impact points
Right-Sided Pulmonary Venous Obstruction Between a Right Aortic Arch and an Amplatzer Septal Occlusion Device Following Closure of a Secundum Atrial Septal Defect.
Pediatric cardiology. 05/2009;
Right-sided pulmonary venous obstruction between a right aortic arch and an Amplatzer Septal Occluder device developed following closure of a large secundum atrial septal defect. The obstruction was not apparent on postprocedure transesophageal echocardiogram but developed over time. The patient rec... [more] Right-sided pulmonary venous obstruction between a right aortic arch and an Amplatzer Septal Occluder device developed following closure of a large secundum atrial septal defect. The obstruction was not apparent on postprocedure transesophageal echocardiogram but developed over time. The patient recovered completely following surgical removal of the device.
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3.06Impact points
Pharmacokinetics and safety of intravenously administered citrulline in children undergoing congenital heart surgery: potential therapy for postoperative pulmonary hypertension.
The Journal of thoracic and cardiovascular surgery. 09/2007; 134(2):319-26.
OBJECTIVE: Pulmonary hypertension may complicate surgical correction of congenital heart defects, resulting in increased morbidity and mortality. We have previously shown that plasma levels of the nitric oxide precursors citrulline and arginine drop precipitously after congenital cardiac surgery and... [more] OBJECTIVE: Pulmonary hypertension may complicate surgical correction of congenital heart defects, resulting in increased morbidity and mortality. We have previously shown that plasma levels of the nitric oxide precursors citrulline and arginine drop precipitously after congenital cardiac surgery and that oral citrulline supplementation may be protective against the development of pulmonary hypertension. In this study, we assessed the safety and pharmacokinetic profile of intravenous citrulline as a potential therapy for postoperative pulmonary hypertension. METHODS: The initial phase of this investigation was a dose-escalation study of intravenously administered citrulline in infants and children undergoing one of five congenital cardiac surgical procedures (phase 1). The primary safety outcome was a 20% drop in mean arterial blood pressure from the baseline pressure recorded after admission to the intensive care unit. Based on our previous work, the target circulating plasma citrulline trough was 80 to 100 micromol/L. Each patient was given two separate doses of citrulline: the first in the operating room immediately after initiation of cardiopulmonary bypass and the second 4 hours later in the pediatric intensive care unit. Stepwise dose escalations included 50 mg/kg, 100 mg/kg, and 150 mg/kg. After model-dependent pharmacokinetic analysis, we enrolled an additional 9 patients (phase 2) in an optimized dosing protocol that replaced the postoperative dose with a continuous infusion of citrulline at 9 mg/(kg.h) for 48 hours postoperatively. RESULTS: The initial stepwise escalation protocol (phase 1) revealed that an intravenous citrulline dose of 150 mg/kg given after initiation of cardiopulmonary bypass yielded a trough level of in the target range of approximately 80 to 100 micromol/L 4 hours later. The postoperative dose revealed that the clearance of intravenously administered citrulline was 0.6 L/(h.kg), with a volume of distribution of 0.9 L/kg and estimated half-life of 60 minutes. Because of the short half-life, we altered the protocol to replace the postoperative dose with a continuous infusion of 9 mg/(kg.h). An additional 9 patients were studied with this continuous infusion protocol (phase 2). Mean plasma citrulline levels were maintained at approximately 125 mumol/L, with a calculated clearance of 0.52 L/(h.kg). None of the 17 patients studied had a 20% drop in mean arterial blood pressure from baseline. CONCLUSIONS: In this first report of the use of intravenous citrulline in humans, we found citrulline to be both safe and well tolerated in infants and young children undergoing congenital cardiac surgery. Because of the rapid clearance, the optimal dosing regimen was identified as an initial bolus of 150 mg/kg given at the initiation of cardiopulmonary bypass, followed 4 hours later by a postoperative infusion of 9 mg/(kg.h) continued up to 48 hours. Using this regimen, plasma arginine, citrulline, and nitric oxide metabolite levels were well maintained. Intravenous citrulline needs to be studied further as a potential therapy for postoperative pulmonary hypertension.
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3.64Impact points
Recombinant factor seven therapy for postoperative bleeding in neonatal and pediatric cardiac surgery.
The Annals of thoracic surgery. 08/2007; 84(1):161-8.
BACKGROUND: Severe bleeding is a major complication in the postoperative pediatric cardiac surgery patients. We evaluated the efficacy and safety of recombinant factor seven (rFVIIa) therapy in this patient population. METHODS: A retrospective unmatched case-control study for the previous five years... [more] BACKGROUND: Severe bleeding is a major complication in the postoperative pediatric cardiac surgery patients. We evaluated the efficacy and safety of recombinant factor seven (rFVIIa) therapy in this patient population. METHODS: A retrospective unmatched case-control study for the previous five years in a single institution was undertaken. Patients with severe bleeding treated with rFVIIa therapy (study group) were compared with patients treated with blood products only (control group) using analysis of variance. Mediastinal bleeding, blood products transfusion, and coagulation studies before and six hours after the first dose of rFVIIa therapy were analyzed using the Student paired t test. The dose, frequency, and side-effects of rFVIIa therapy were studied. RESULTS: Forty-six patients with severe bleeding were studied. Twenty-three of 24 patients in the study group, including 12 patients placed on extracorporeal membrane oxygenation (ECMO), responded to rFVIIa therapy (mean dose 43 +/- 22.9 microg/kg/dose). There was significant reduction in chest tube drainage (from 52.3 +/- 36.1 mL/kg/hour to 18.8 +/- 20.9 mL/kg/hour, p = 0.0003) along with significant reduction of blood products transfusion (p < 0.001) in the study group patients as compared with control group patients. One patient who failed to respond had surgical bleeding. Two patients developed major thrombotic complications that included clots in the ECMO circuit and thrombosis at bleeding arterial line site resulting in limb ischemia. Four additional patients in the study group developed mediastinal clots. Overall, 25% of patients developed thrombosis after rFVIIa therapy. CONCLUSIONS: The rFVIIa therapy seems to be an effective treatment for severe bleeding in postoperative pediatric cardiac surgery patients in the absence of surgical bleeding. It must be judiciously used in patients bleeding from multiple sites or having preexistent clots in the ECMO circuit to prevent major thrombotic complications.
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4.15Impact points
Genetic variation in the mitochondrial enzyme carbamyl-phosphate synthetase I predisposes children to increased pulmonary artery pressure following surgical repair of congenital heart defects: a validated genetic association study.
Mitochondrion. 05/2007; 7(3):204-10.
Increased pulmonary artery pressure (PAP) can complicate the postoperative care of children undergoing surgical repair of congenital heart defects. Endogenous NO regulates PAP and is derived from arginine supplied by the urea cycle. The rate-limiting step in the urea cycle is catalyzed by a mitochon... [more] Increased pulmonary artery pressure (PAP) can complicate the postoperative care of children undergoing surgical repair of congenital heart defects. Endogenous NO regulates PAP and is derived from arginine supplied by the urea cycle. The rate-limiting step in the urea cycle is catalyzed by a mitochondrial enzyme, carbamoyl-phosphate synthetase I (CPSI). A well-characterized polymorphism in the gene encoding CPSI (T1405N) has previously been implicated in neonatal pulmonary hypertension. A consecutive modeling cohort of children (N=131) with congenital heart defects requiring surgery was prospectively evaluated to determine key factors associated with increased postoperative PAP, defined as a mean PAP>20 mmHg for at least 1h during the 48h following surgery measured by an indwelling pulmonary artery catheter. Multiple dimensionality reduction (MDR) was used to both internally validate observations and develop optimal two-variable through five-variable models that were tested prospectively in a validation cohort (N=41). Unconditional logistic regression analysis of the modeling cohort revealed that age (OR=0.92, p=0.01), CPSI T1405N genotype (AC vs. AA: OR=4.08, p=0.04, CC vs. AA: OR=5.96, p=0.01), and Down syndrome (OR=5.25, p=0.04) were independent predictors of this complex phenotype. MDR predicted that the best two-variable model consisted of age and CPSI T1405N genotype (p<0.001). This two-variable model correctly predicted 73% of the outcomes from the validation cohort. A five-variable model that added race, gender and Down's syndrome was not significantly better than the two-variable model. In conclusion, the CPSI T1405N genotype appears to be an important new factor in predicting susceptibility to increased PAP following surgical repair of congenital cardiac defects in children.
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3.64Impact points
Rapid diagnosis of cannula migration by cerebral oximetry in neonatal arch repair.
The Annals of thoracic surgery. 08/2006; 82(1):325-7.
Although it has gained much interest in other surgical specialties, the application of near-infrared spectroscopy to assess cerebral perfusion during cardiac surgery is relatively new. Regional cerebral oxygen saturation (rSO2) is a function of cerebral oxygen supply and demand. Continuous monitorin... [more] Although it has gained much interest in other surgical specialties, the application of near-infrared spectroscopy to assess cerebral perfusion during cardiac surgery is relatively new. Regional cerebral oxygen saturation (rSO2) is a function of cerebral oxygen supply and demand. Continuous monitoring of the rSO2 permits early detection of cerebral ischemia allowing for prompt intervention. The following is a description of a repair of truncus arteriosus with type A interrupted aortic arch during which continuous cerebral oximetry assisted with the positioning of the arterial cannula avoiding a prolonged episode of cerebral ischemia.
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3.06Impact points
Nitric oxide precursors and congenital heart surgery: a randomized controlled trial of oral citrulline.
The Journal of thoracic and cardiovascular surgery. 08/2006; 132(1):58-65.
OBJECTIVE: The study sought to determine whether citrulline supplementation, a precursor to nitric oxide synthesis, is safe and efficacious in increasing plasma citrulline concentrations and decreasing the risk of postoperative pulmonary hypertension. STUDY DESIGN: Forty children, undergoing cardiop... [more] OBJECTIVE: The study sought to determine whether citrulline supplementation, a precursor to nitric oxide synthesis, is safe and efficacious in increasing plasma citrulline concentrations and decreasing the risk of postoperative pulmonary hypertension. STUDY DESIGN: Forty children, undergoing cardiopulmonary bypass and at risk for pulmonary hypertension, were randomized to receive 5 perioperative doses (1.9 g/m2 per dose) of either oral citrulline or placebo. Plasma citrulline and arginine concentrations were measured at 5 time points. Measurements of systemic blood pressure and presence of pulmonary hypertension were collected. RESULTS: Median citrulline concentrations were significantly higher in the citrulline group versus the placebo group immediately postoperatively (36 micromol/L vs 26 micromol/L, P = .012) and at 12 hours postoperatively (37 micromol/L vs 20 micromol/L, P = .015). Mean plasma arginine concentrations were significantly higher in the citrulline group versus the placebo group by 12 hours postoperatively (36 micromol/L vs 23 micromol/L, P = .037). Mean systemic blood pressure did not differ between groups (P = .53). Postoperative pulmonary hypertension developed in 9 patients, 6 of 20 (30%) in the placebo group and 3 of 20 (15%) in the citrulline group (P = .451), all of whom had plasma citrulline concentrations less than age-specific norms. Postoperative pulmonary hypertension did not develop in patients who demonstrated plasma citrulline concentrations in excess of 37 mumol/L (P = .036). CONCLUSIONS: Oral citrulline supplementation safely increased plasma citrulline and arginine concentrations compared with placebo after cardiopulmonary bypass. Postoperative pulmonary hypertension did not occur in children with naturally elevated citrulline levels or elevations through supplementation. Oral citrulline supplementation may be effective in reducing postoperative pulmonary hypertension.
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3.64Impact points
Plastic bronchitis: is thoracic duct ligation a real surgical option?
The Annals of thoracic surgery. 07/2006; 81(6):2281-3.
Plastic bronchitis is an unusual clinical scenario of unknown cause and occurs in multiple clinical settings. The disease is characterized by the development of arborizing, thick, tenacious casts of the tracheobronchial tree that results in airway obstruction. Patients with congenital heart disease ... [more] Plastic bronchitis is an unusual clinical scenario of unknown cause and occurs in multiple clinical settings. The disease is characterized by the development of arborizing, thick, tenacious casts of the tracheobronchial tree that results in airway obstruction. Patients with congenital heart disease who have undergone a Fontan operation are at high risk for having this problem develop. Management of this distressing situation is difficult with only palliative options being available, such as repeated bronchoscopies, inhaled heparin, tissue plasminogen activator, inhaled bronchodilators, or azithromycin. The patients with Fontan circuits have a myriad of unique complications develop, such as atrial arrhythmias, recurrent pleural effusions, chylothoraces, protein-losing enteropathy, and plastic bronchitis. High intrathoracic lymphatic pressures with nondemonstrable lympho-bronchial fistulas were believed to be the cause for the development of these recurrent bronchial casts in plastic bronchitis. Faced with recurrent plastic bronchitis resistant to medical management in 2 Fontan patients with normal Fontan pressures on cardiac catheterization, we decided to explore a surgical solution by performing a thoracic duct ligation. This resulted in complete resolution of the formation of casts in both patients, who were discharged home and remain asymptomatic on continued follow-up. Thoracic duct ligation provides a surgical cure for plastic bronchitis by decreasing intrathoracic lymphatic pressure and flow.
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3.64Impact points
Inhaled nitric oxide use in bidirectional Glenn anastomosis for elevated Glenn pressures.
The Annals of thoracic surgery. 04/2006; 81(4):1429-34.
BACKGROUND: Children frequently undergo bidirectional Glenn anastomosis in the staged surgical management of single ventricle physiology. The purpose of our study was to investigate the role of inhaled nitric oxide therapy in children with marked elevations in Glenn pressures after this surgery. MET... [more] BACKGROUND: Children frequently undergo bidirectional Glenn anastomosis in the staged surgical management of single ventricle physiology. The purpose of our study was to investigate the role of inhaled nitric oxide therapy in children with marked elevations in Glenn pressures after this surgery. METHODS: A retrospective study over a 30-month period was performed. The effect of inhaled nitric oxide therapy was analyzed in children with marked elevations of Glenn pressures resulting in decreased systemic perfusion. Effects on Glenn pressures, respiratory indices, and systemic perfusion were evaluated after initiation of nitric oxide therapy and compared with baseline parameters. RESULTS: Sixteen patients were placed on nitric oxide therapy for marked elevations of Glenn pressures (22.4 +/- 3.9 mm Hg). In the 11 responsive patients, there were significant reductions in Glenn pressures (from 22.4 mm Hg to 17.1 mm Hg, p < 0.001) and significant improvement in partial pressure of oxygen to fraction of inspired oxygen ratio (from 49 to 74.3, p = 0.001) and oxygenation index (from 17 to 12, p = 0.005). There was simultaneous significant reduction in inotrope score (from 14.9 to 11.4, p < 0.001) and fluid volume support (from 11.4 mL/kg to 2.3 mL/kg, p < 0.001) in the responsive patients. Five patients that failed to show any response were found, subsequently, to have an anatomic lesion. CONCLUSIONS: Inhaled nitric oxide produces significant reduction in Glenn pressures and improvement in systemic perfusion and pulmonary gas exchange in patients with marked elevations of Glenn pressures after bidirectional Glenn anastomosis. Patients who fail to respond should be investigated for an anatomic lesion.
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4.23Impact points
Specificity and sensitivity of automated external defibrillator rhythm analysis in infants and children.
Annals of emergency medicine. 09/2003; 42(2):185-96.
STUDY OBJECTIVES: The rhythm detection algorithms of automated external defibrillators have been derived from adult rhythms, and their ability to discriminate between shockable and nonshockable rhythms in children is largely unknown. This study evaluates the performance of 1 automated external defib... [more] STUDY OBJECTIVES: The rhythm detection algorithms of automated external defibrillators have been derived from adult rhythms, and their ability to discriminate between shockable and nonshockable rhythms in children is largely unknown. This study evaluates the performance of 1 automated external defibrillator algorithm in infants and children and evaluates algorithm performance with anterior-posterior versus sternal-apex lead placement. METHODS: We enrolled pediatric patients in a critical care unit, an electrophysiology laboratory, and a cardiac operating room. A monitor-defibrillator recorded ECGs by means of standard defibrillation-monitor pads. Selected 15-second rhythm samples were played into a LIFEPAK 500 automated external defibrillator, and the automated external defibrillator "shock/no shock" decision was documented. To determine sensitivity and specificity, the automated external defibrillator decision was compared with the "shockable" versus "nonshockable" rhythm classification provided by 3 expert clinicians who were blinded to the automated external defibrillator decision. RESULTS: We recorded 1,561 rhythm samples from 203 pediatric patients (median age 11 months; range, day of birth to 7 years). The automated external defibrillator recommended a shock for 72 of 73 rhythm samples classified as coarse ventricular fibrillation by expert review (sensitivity 99%; 95% confidence interval [CI] 93% to 100%); and correctly reached a "no shock advised" decision for 1,465 of 1,472 rhythm samples classified as nonshockable by experts (specificity 99.5%). Specificity was 99.1% (95% CI 97.8% to 99.8%) with the sternal-apex lead and 99.4% (95% CI 98.1% to 99.9%) with the anterior-posterior lead. CONCLUSION: This automated external defibrillator algorithm has high specificity and sensitivity when used in infants and children with either sternal-apex or anterior-posterior lead placement.
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3.64Impact points
A modified bronchial anastomosis technique for lung transplantation.
The Annals of thoracic surgery. 07/2003; 75(6):1697-704.
BACKGROUND: Low rates of major complications have been reported for the intussuscepting bronchial anastomotic technique but stenosis, malacia, and granulation tissue at the anastomosis may cause clinically important morbidity. We hypothesized that a modification of the telescoping technique that imp... [more] BACKGROUND: Low rates of major complications have been reported for the intussuscepting bronchial anastomotic technique but stenosis, malacia, and granulation tissue at the anastomosis may cause clinically important morbidity. We hypothesized that a modification of the telescoping technique that improves bronchial wall apposition might be associated with improved bronchial healing and clinical outcomes. METHODS: The telescoping horizontal mattress "U-stitch" suture technique was modified to incorporate figure-of-eight sutures placed in the cartilaginous wall between each of three intussuscepting U stitches. Serial videotape records of 152 individual anastomoses (99 modified, 53 telescoped) in 118 consecutive operative survivors were retrospectively reviewed by examiners blinded with respect to technique used. Stenosis, airway instability, mucosa quality, and devascularized luminal tissue were graded at 4 to 14 days (initial), 4 to 12 weeks (early), and 6 to 12 months (late) after transplantation. RESULTS: The incidence of anastomotic stenosis was significantly lower using the modified technique at the initial (p = 0.025) and late (p = 0.015) observations. In the initial phase airway instability (p = 0.015) and devascularization grades (p = 0.001) were also significant lower in the modified group. There were no significant differences in mucosal condition between techniques. The modified telescoping technique was associated with significant survival advantage (mean 17.7%; p = 0.029) by multivariate analysis. The incidence of major airway complications (dehiscences and stenoses required stents) tended to be lower (3% versus 6%) in the modified group. CONCLUSIONS: The modified telescoping bronchial anastomosis technique is associated with improved early and late bronchial healing and higher 5-year survival without increased major airway complications.
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4.02Impact points
Effect of cardiopulmonary bypass on urea cycle intermediates and nitric oxide levels after congenital heart surgery.
The Journal of pediatrics. 02/2003; 142(1):26-30.
OBJECTIVE: To test the hypothesis that cardiopulmonary bypass used for repair of ventricular septal defects and atrioventricular septal defects would decrease availability of urea cycle intermediates including arginine and subsequent nitric oxide availability. STUDY DESIGN: Consecutive infants (n = ... [more] OBJECTIVE: To test the hypothesis that cardiopulmonary bypass used for repair of ventricular septal defects and atrioventricular septal defects would decrease availability of urea cycle intermediates including arginine and subsequent nitric oxide availability. STUDY DESIGN: Consecutive infants (n = 26) undergoing cardiopulmonary bypass for repair of an unrestrictive ventricular septal defect or atrioventricular septal defect were studied. Blood samples were collected immediately before surgery, immediately after surgery, and 12 hours, 24 hours, and 48 hours after surgery. Urea cycle intermediates, including citrulline, arginine, and ornithine, were measured by amino acid analysis. Nitric oxide metabolites were measured by means of the modified Griess reaction. RESULTS: Cardiopulmonary bypass caused a significant decrease in the urea cycle intermediates arginine, citrulline, and ornithine at all postoperative time points compared with preoperative levels. The ratio of ornithine to citrulline, a marker of urea cycle function, was elevated at all postoperative time points compared with preoperative values, indicating decreased urea cycle function. Nitric oxide metabolites were significantly decreased at all postoperative time points except for 48 hours, compared with preoperative levels. CONCLUSIONS: Cardiopulmonary bypass significantly decreases availability of arginine, citrulline, and nitric oxide metabolites in the postoperative period. Decreased availability of nitric oxide precursors may contribute to the increased risk of postoperative pulmonary hypertension.
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3.64Impact points
Left ventricular assist device implantation via left thoracotomy: alternative to repeat sternotomy.
The Annals of thoracic surgery. 04/2002; 73(3):997-9.
Repeat sternotomy for left ventricular assist device insertion may result in injury to the right heart or patent coronary grafts, complicating intraoperative and postoperative management. In 4 critically ill patients, left thoracotomy was used as an alternative to repeat sternotomy. Anastomosis of t... [more] Repeat sternotomy for left ventricular assist device insertion may result in injury to the right heart or patent coronary grafts, complicating intraoperative and postoperative management. In 4 critically ill patients, left thoracotomy was used as an alternative to repeat sternotomy. Anastomosis of the outflow conduit to the descending thoracic aorta provided satisfactory hemodynamic support.
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0.92Impact points
Cardiac surgery in patients with moderate renal impairment.
Southern medical journal. 03/2002; 95(3):321-3.
BACKGROUND: There is a paucity of information concerning the results of cardiac surgery in patients with moderate impairment of renal function. We reviewed our recent experience to determine the results of operation and the long-term outcome. METHODS: Since January 1992, we have performed cardiac su... [more] BACKGROUND: There is a paucity of information concerning the results of cardiac surgery in patients with moderate impairment of renal function. We reviewed our recent experience to determine the results of operation and the long-term outcome. METHODS: Since January 1992, we have performed cardiac surgical procedures utilizing total cardiopulmonary bypass on 57 adult patients with preoperative serum creatinine values > or = 2.0 mg/dL and no history of dialysis. Operative procedures done were coronary artery bypass (39 patients), repeated coronary artery bypass (2), valve replacement with or without coronary artery bypass (12), and other procedures (4). RESULTS: No operative deaths occurred. There were 3 hospital deaths. Only 5 patients required perioperative dialysis; in 5 additional patients, chronic dialysis was begun from 4 to 24 months postoperatively. The surviving patients who were not receiving dialysis had a mean creatinine value of 2.4 mg/dL at most recent follow-up. CONCLUSIONS: Adult patients with moderate renal impairment can safely have major cardiac procedures. The majority of patients maintain stable renal function postoperatively. The overall results of cardiac surgery in this patient population are good.
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1.15Impact points
Cardiac surgery after renal transplantation.
The American surgeon. 03/2002; 68(2):154-8.
Renal transplantation remains a mainstay of therapy for end-stage renal disease. Cardiac disease has a high prevalence in this patient population. This study reviews the factors and outcomes associated with cardiac surgery in renal transplant recipients. We performed a retrospective review of all pa... [more] Renal transplantation remains a mainstay of therapy for end-stage renal disease. Cardiac disease has a high prevalence in this patient population. This study reviews the factors and outcomes associated with cardiac surgery in renal transplant recipients. We performed a retrospective review of all patients at our institution with a functioning renal allograft at the time of their cardiac surgical procedure. Between June 1971 and April 2000, 2343 patients underwent renal transplantation at Vanderbilt University Medical Center. Twenty-six patients with a functioning renal allograft subsequently underwent a cardiac procedure requiring cardiopulmonary bypass. There were 11 women and 15 men. Twenty-four patients underwent coronary bypass, one had a double valve replacement, and one had a combined coronary bypass/valve replacement. The interval from renal transplant to heart surgery ranged between 0.6 and 227 months (mean 79.1). Operative mortality was zero but there were two hospital deaths: one due to multisystem organ failure and one due to pulmonary embolism. Six additional patients died late with only one due to heart disease. Four patients required perioperative dialysis, and one of these went on to require permanent dialysis. Two additional patients returned to dialysis late postoperatively. The requirement for acute perioperative dialysis was predicted by preoperative creatinine, hematocrit, and intraoperative urine output. The overall survival is 69 per cent (18 of 26) with a median follow-up of 38 months. The majority of long-term survivors have minimal cardiac symptoms. Standard cardiac surgery procedures can be performed with relative safety in patients with functioning renal allografts. The incidence of perioperative and late development of renal failure requiring dialysis is low. The long-term survival and symptomatic improvement achieved are favorable and warrant continued performance of cardiac surgery in patients with functioning renal allografts.
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3.64Impact points
Extracorporeal membrane oxygenation in children after repair of congenital cardiac lesions.
The Annals of thoracic surgery. 12/2001; 72(6):2095-101; discussion 2101-2.
BACKGROUND: The purpose of this study was to review our experience in the early application of extracorporeal membrane oxygenation (ECMO) in patients requiring mechanical assistance after cardiac surgical procedures. METHODS: The hospital records of all children requiring ECMO after cardiac operatio... [more] BACKGROUND: The purpose of this study was to review our experience in the early application of extracorporeal membrane oxygenation (ECMO) in patients requiring mechanical assistance after cardiac surgical procedures. METHODS: The hospital records of all children requiring ECMO after cardiac operation were retrospectively reviewed, and an analysis of variables affecting survival was performed. RESULTS: Fifty pediatric patients between May 1997 and October 2000 required ECMO for cardiopulmonary support after cardiac operation. Patients ranged in age from 1 day to 11 years (median age, 40 days). Forty-eight patients underwent repair of congenital cardiac lesions and 2 were included after receiving a heart transplant. Twenty-two children could not be weaned from cardiopulmonary bypass and were placed on ECMO in the operating room for circulatory support. Of the 28 children who required ECMO in the intensive care unit, 10 had ECMO instituted after cardiopulmonary arrest (mean cardiopulmonary resuscitation time 42 minutes; range, 5 to 110 minutes). In infants with single-ventricle physiology, survival to discharge was 61% (11 of 18 patients) as compared with 43% (14 of 32 patients) in those with biventricular physiology. Thirty of the 50 patients (60%) were successfully weaned from ECMO, of which 25 (83%) were discharged home. Overall survival to discharge in the entire cohort was 50%. Extracorporeal membrane oxygenation support greater than 72 hours was a grave prognostic indicator. Overall survival in this group was 36% (9 of 25 patients) compared with 56% (14 of 25 patients) in those with ECMO support less than 72 hours (p < 0.05). Univariate analysis revealed the presence of renal failure, extended periods of circulatory support, and a prolonged period of cardiopulmonary resuscitation as risk factors for mortality. The presence of shunt-dependent flow, operative procedure, and institution of ECMO in the intensive care unit did not alter survival. CONCLUSIONS: Extracorporeal membrane oxygenation provides effective support for postoperative cardiac and pulmonary failure refractory to medical management. Early institution of ECMO may decrease the incidence of cardiac arrest and end-organ damage, thus increasing survival in these critically ill patients.
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Methemoglobinemia: Toxicity of inhaled nitric oxide therapy.
Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies. 02/2001; 2(1):99-101.
Elevation in methemoglobin is a known toxicity of inhaled nitric oxide (NO) therapy. This article describes two significant episodes of methemoglobinemia. These cases illustrate the probable cause and the treatment strategies for the potential for delivery of high concentrations of NO, resulting in ... [more] Elevation in methemoglobin is a known toxicity of inhaled nitric oxide (NO) therapy. This article describes two significant episodes of methemoglobinemia. These cases illustrate the probable cause and the treatment strategies for the potential for delivery of high concentrations of NO, resulting in methemoglobinemia with moderate and even low-dose delivered NO. We propose mechanisms for this occurrence and means of prevention.
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3.64Impact points
Long-lasting improvement after septal myectomy for hypertrophic obstructive cardiomyopathy.
The Annals of thoracic surgery. 07/2000; 69(6):1732-5; discussion 1735-6.
BACKGROUND: The most effective treatment of symptomatic patients with hypertrophic obstructive cardiomyopathy is still disputed. Treatment options include medical therapy, pacemaker insertion, percutaneous transluminal septal myocardial ablation, mitral valve replacement, and surgical resection of o... [more] BACKGROUND: The most effective treatment of symptomatic patients with hypertrophic obstructive cardiomyopathy is still disputed. Treatment options include medical therapy, pacemaker insertion, percutaneous transluminal septal myocardial ablation, mitral valve replacement, and surgical resection of obstructing muscle. The long-term results of the various treatment options are not well defined. We aimed to demonstrate that septal myectomy is efficacious in reducing or abolishing left ventricular outflow tract gradient and leads to long-lasting symptomatic improvement in most patients. METHODS: Twenty-two consecutive patients had septal myectomy between 1981 and the present. Their records were reviewed to document the details of their preoperative status, hospital course, their subsequent clinical outcome, and current status. RESULTS: Mean age at operation was 31.3 years. Preoperatively all patients were disabled by typical symptoms despite aggressive medical treatment. Mean resting gradient was 78 mm Hg. Nine patients required simultaneous associated cardiac procedures. There were no perioperative deaths and minimal morbidity. Two patients died at 6 and 9 years postoperatively of congestive heart failure and arrhythmias. Long-term survivors have been followed up for a mean of 6.6 years. Currently all have minimal or no symptoms. The mean resting gradient was 12 mm Hg. No patient has required reoperation for residual obstruction. CONCLUSIONS: Septal myectomy reduces or abolishes left ventricular outflow tract gradient in hypertrophic obstructive cardiomyopathy. Myectomy provides long-lasting symptomatic improvement in most patients. The clinical status of patients late postoperatively can be affected by arrhythmias and myocardial dysfunction.
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1.39Impact points
Clinical outcomes of 84 children with congenital heart disease managed with extracorporeal membrane oxygenation after cardiac surgery.
ASAIO journal (American Society for Artificial Internal Organs : 1992). 51(5):504-7.
The purpose of our research was to study the clinical outcomes of children with congenital heart disease (CHD) requiring extracorporeal membrane oxygenation (ECMO) support after cardiac surgery at a tertiary care children's hospital. Retrospective review of all patients with CHD who required pos... [more] The purpose of our research was to study the clinical outcomes of children with congenital heart disease (CHD) requiring extracorporeal membrane oxygenation (ECMO) support after cardiac surgery at a tertiary care children's hospital. Retrospective review of all patients with CHD who required postcardiotomy ECMO between January 2001 and September 2004 (45 months) was undertaken. Various outcome predictors were tested for any association with survival to hospital discharge using univariate analysis. A total of 84 children were placed on ECMO after CHD surgery; 39 (46.4%) were placed on ECMO in the operating room. Median age of the patients was 128 days (1 day to 5 years) and median weight was 4.53 kg (2-18 kg). Active cardiopulmonary resuscitation was ongoing at the time of cannulation in 27 children (32%). Fifty-two children (61.9) survived > 24 hours after decannulation and 31 (36.9%) survived to discharge. High arterial serum lactate levels at the time of ECMO initiation were strongly correlated with nonsurvival (p = 0.004). Nonsurvivors had longer duration on ECMO than survivors (p = 0.003). The odds of survival dropped significantly after 144 hours (day 6) of ECMO. ECMO support results in improved outcomes in patients who suffered hemodynamic collapse post cardiac surgery. Underlying cardiac lesion, age, weight, gender, initial arterial pH, location of ECMO initiation, need for hemofiltration and placement of ECMO after active ongoing cardiopulmonary resuscitation did not increase the mortality risk. Initial arterial serum lactate level and inability to wean off by 6 days were strongly correlated with nonsurvival.
Following (4)
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Jason H Moore
Dartmouth College -
Marshall L Summar
Children's National Medical Center -
Marylyn D Ritchie
Pennsylvania State University -
Aaron P Milstone
Williamson Medical Center
