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Biomedical subjects

K R Kanter

Publications and source records attributed to K R Kanter.

At least 37 records · Page 2Linked to original sources
PubMed1997

A comparison of the hemodynamic effects of amrinone and sodium nitroprusside in infants after cardiac surgery.

The phosphodiesterase inhibitor amrinone (AMR) increases cardiac output in children after cardiac surgery. In vitro, amrinone has both positive inotropic and vasodilatory effects. However the relative contribution of these effects to the increases in cardiac output observed clinically is unclear, and it has not been demonstrated that amrinone offers a hemodynamic advantage above that of pure vasodilators in infants. We compared the hemodynamic effects of AMR and sodium nitroprusside (SNP) in 10 infants after cardiac surgery. Cardiac index (CI) was measured by thermodilution after SNP administration, titrated to decrease mean blood pressure (MBP) by 20%, and then after a 1.5-mg/kg bolus dose of AMR. Each patient served as his or her own control. Preload, as measured by left atrial pressure and transesophageal echocardiography (in eight patients), was kept constant throughout the protocol. Both SNP and AMR caused significant decreases in MBP and systemic vascular resistance index (SVRI). However, only AMR resulted in a significant increase in CI. The ratio of fractional increase in CI to fractional absolute decrease in MBP was significantly greater for AMR than SNP, indicating greater efficacy for AMR in the treatment of low cardiac output syndrome and suggesting that, in infants after cardiac surgery, AMR has clinically relevant positive inotropic effects.

Amrinone↗
PubMed1997

Predicting and treating coagulopathies after cardiopulmonary bypass in children.

UNLABELLED: Coagulopathies in children after cardiopulmonary bypass (CPB) are complex. There are very limited data correlating coagulation tests with postoperative bleeding. We evaluated coagulation changes after CPB and after the administration of coagulation products to 75 children. Baseline coagulation tests were obtained and repeated after protamine administration, after transfusion of individual coagulation products, and on arrival in the intensive care unit (ICU). Regression analysis demonstrated no baseline coagulation test to predict postoperative chest tube drainage. Weight and duration of CPB were determined to be the only predictors of bleeding. Further analyses demonstrated that children <8 kg had more bleeding and required more coagulation products than children >8 kg. Postprotamine platelet count and fibrinogen level correlated independently with 24-h chest tube drainage in children <8 kg, whereas postprotamine platelet count and thrombelastographic values did so in patients weighing >8 kg. Platelet administration alone was found to restore effective hemostasis in many patients. With ongoing bleeding, cryoprecipitate improved coagulation parameters and limited blood loss. Fresh-frozen plasma administration after platelets worsened coagulation parameters and was associated with greater chest tube drainage and more coagulation product transfusions in the ICU. Objective data to guide post-CPB component therapy transfusion in children are suggested. IMPLICATIONS: Children <8 kg can be expected to have more severe coagulopathies, require more coagulation product transfusions, and bleed more after cardiopulmonary bypass. Correlations between coagulation tests and postoperative chest tube drainage are defined. Platelets and, if necessary, cryoprecipitate optimally restore hemostasis. Fresh-frozen plasma offers no benefits in correcting postcardiopulmonary bypass coagulopathies in children.

Anticoagulants↗
PubMed1997

Medium-term results of pediatric patients undergoing orthotopic heart transplantation.

To establish the medium-term results of our transplant population, we retrospectively reviewed the charts of 51 consecutive patients who underwent orthotopic heart transplantation between July 1988 and April 1995. These patients comprised two groups: group A consists of 26 patients (age 6 days to 16.4 years, median 1.4 years) with no previous heart surgery, and group B consists of 25 patients (ages 0.1 to 14.3 years, median 8.3 years), all of whom had heart surgery before undergoing transplantation. There was no difference between these groups in early or late survival rates, and neither age at transplantation nor sex was an indicator of survival. There have been 14 deaths, six early (before hospital discharge) and eight late. Early deaths have predominantly been attributed to long-term ventilation and hemodynamic instability before transplantation, and late deaths to graft coronary artery disease (n = 4), acute coronary vasculitis (n = 3), and acute cellular rejection (n = 1). Although infection has resulted in significant morbidity (57 hospital admissions), there have been no late deaths resulting from infection. Sepsis accounts for four early deaths in chronically ill patients. Orthotopic heart transplantation in the pediatric patient with and without previous heart surgery is a viable option for those with end-stage heart disease and those in whom other surgical options carry a prohibitively high mortality rate.

Actuarial Analysis↗
PubMed1996

Single lung transplantation followed by contralateral bullectomy for bullous emphysema.

BACKGROUND AND METHODS: Single lung transplantation for emphysema is now standard practice despite initial concerns, including the possibility that the compliant diseased lung would compress the transplanted lung as a result of hyperinflation. We describe a patient with severe bilateral bullous emphysema and alpha-1-antitrypsin deficiency who underwent single lung transplantation after which hyperinflation of the native lung led to significant compression of the pulmonary allograft. The patient subsequently underwent bullectomy of the contralateral lung with marked improvement in his functional status. RESULTS: After bullectomy, the patient's forced expiratory volume in 1 second increased from 1.77 to 2.82 L, his total lung capacity fell from 7.23 to 6.19 L, and his 6-minute walk increased from 724 to 1269 feet. However, 7 months after bullectomy, there was evidence that the bullous disease in the native lung was recurring. CONCLUSIONS: Significant hyperinflation of the native lung with compromise of the pulmonary allograft can occur after single lung transplantation for bullous emphysema. Bullectomy of the diseased lung after transplantation improved allograft function in our patient. Alternatively, bilateral lung transplantation for severe bilateral bullous emphysema may be considered.

Humans↗
PubMed1995

Successful application of the Norwood procedure for infants without hypoplastic left heart syndrome.

Although the first-stage Norwood procedure mostly has been used for hypoplastic left heart syndrome, there are other anomalies in which the Norwood procedure can be applied. Since 1991, 18 newborns without hypoplastic left heart syndrome underwent a first-stage Norwood procedure. All had a hypoplastic aortic annulus, ascending aorta, and transverse aorta. Ten had normally related great arteries: aortic atresia or aortic stenosis with inadequate left ventricle in 4, mitral atresia or stenosis in 4, and interrupted aortic arch in 2. The 8 others had double-outlet right ventricle with mitral atresia or complete transposition with a hypoplastic right ventricle. Age ranged from 2 to 77 days (median, 6 days) and weight from 2.4 to 4.4 kg (mean, 3.0 kg). The patients with interrupted aortic arch simultaneously underwent primary repair of the interruption. There were 17 hospital survivors (94%). There have been no late deaths in follow-up from 4 to 30 months (mean, 15.5 months). Thirteen children have had subsequent creation of a bidirectional Glenn shunt with takedown of the original systemic to pulmonary shunt. The 2 with interrupted aortic arch underwent a Rastelli-type biventricular repair. These results show that the Norwood procedure can be applied to infants without hypoplastic left heart syndrome who have hypoplastic aortas and excessive pulmonary blood flow with very low mortality and excellent palliation.

Aorta↗
PubMed1993

Diagnosis of pulmonary toxoplasmosis by bronchoalveolar lavage in cardiac transplant recipients.

We report two cases of fatal, clinically unsuspected disseminated toxoplasmosis that developed following orthotopic cardiac transplantation. Toxoplasma gondii trophozoites, pseudocysts, and cysts were best visualized on hematoxylin and eosin and Giemsa-stained cytospin preparations of bronchoalveolar lavage fluid. Post-mortem examination in both cases revealed disseminated toxoplasmosis with extensive involvement of the lungs and heart. The patients, who were seronegative for antibody to T. gondii prior to transplantation, received organs from donors whose serology status was unknown. Demonstration of anti-toxoplasma antibodies post-transplantation occurred in both cases. Bronchoalveolar lavage may be useful in diagnosis of pulmonary toxoplasmosis. Clinicians, pathologists, and cytopathologists must consider T. gondii in the differential diagnosis of pneumonia in the immunocompromised patient, especially cardiac transplant patients.

Adult↗
PubMed1992

The usefulness of echocardiography in the surgical management of infants with congenital heart disease.

Between January 1988 and August 1991, at The Children's Heart Center, Atlanta, 83 infants with congenital heart defects were diagnosed by echocardiography and underwent surgery without cardiac catheterization. The diagnostic categories included 46 infants with left heart obstructive lesions, 19 infants with cyanotic heart lesions, and 18 infants with miscellaneous lesions. Forty-five infants (55%) underwent surgery under cardiopulmonary bypass. There were three errors in diagnosis, yielding a diagnostic accuracy of 95%. Many infants with congenital heart disease can be accurately and completely diagnosed by echocardiography and can safely undergo surgery without cardiac catheterization.

Aortic Coarctation↗
PubMed1989

Use of the Pierce-Donachy ventricular assist device in patients with cardiogenic shock after cardiac operations.

In spite of recent improvements in cardiac surgery, a small percentage of patients have severe postcardiotomy ventricular failure refractory to drugs and the intraaortic balloon. In our experience, the Pierce-Donachy external pneumatic ventricular assist device has proved to be one of the most effective devices for these patients. Since 1981, 30 patients aged 15 to 71 years (mean age, 52 years) with profound cardiogenic shock refractory to conventional therapy after cardiotomy were supported with the Pierce-Donachy ventricular assist device. Fourteen required left ventricular support, 7 needed right ventricular support with an intraaortic balloon, and 9 had biventricular assistance. Duration of support ranged from three hours to 22 days (mean length, 3.6 days). Seven of the first 11 patients seen died in the operating room of bleeding, biventricular failure, or both. However, 16 patients (53%) had improved cardiac function, 15 (50%) were weaned, and 11 (37%) were discharged. Of the last 19 patients in the series, 47% survived. Factors affecting survival were myocardial infarction (75%) and renal failure (90%). Common complications were bleeding (73%) and biventricular failure (83%).

Adolescent↗
PubMed1989

Left subclavian-left coronary artery anastomosis for anomalous origin of the left coronary artery. Long-term follow-up.

From 1972 to 1987, seven patients, from two to 28 months of age, underwent left subclavian artery-left coronary artery anastomosis for anomalous origin of the left coronary artery from the pulmonary trunk. All of these infants, median age 4 months, had severe congestive heart failure caused by anterolateral myocardial infarctions. There were two hospital deaths (29% mortality rate) with no late deaths after an average 10-year follow-up. All survivors have good exercise tolerance New York Heart Association class I), reduction in heart size, and significant improvement or normalization of ventricular function by echocardiography. Patency of the subclavian-left coronary artery anastomosis has been documented in two of four patients who have undergone catheterization. In contrast to other revascularizing procedures for treatment of an anomalous origin of the left coronary artery, anastomosis of the left subclavian to the left coronary artery may be performed without cardiopulmonary bypass or aortic occlusion. Moreover, this procedure appears to have an acceptable mortality rate with excellent long-term functional results in critically ill infants.

Anastomosis, Surgical↗
PubMed1988

The changing profile of the patient undergoing coronary artery bypass surgery.

The first 100 consecutive patients undergoing isolated coronary artery bypass surgery in 1975 were evaluated with respect to the incidence of operative risk factors and outcome. When compared with an identically selected group from 1985, there was significant worsening of the preoperative condition over the decade with regard to mean age (p less than 0.0005), presence of congestive heart failure (p less than 0.05), left ventricular dysfunction (p less than 0.05), severity of coronary artery disease (p less than 0.001) and incidence of emergency operation (p less than 0.05). More patients in 1985 had associated medical diseases such as diabetes (p less than 0.01) and chronic lung disease (p less than 0.005). There was an increase in the occurrence of vascular diseases (hypertension, renal dysfunction, peripheral vascular and cerebrovascular disease) (p less than 0.05). Overall operative mortality increased from 1 to 8% (p less than 0.05) over the decade. Despite the deterioration in the clinical profile of the patient undergoing coronary bypass surgery, elective procedures were still performed with low mortality. The significant increase in overall mortality was chiefly in patients undergoing emergency operation (p less than 0.05). There were also increases in operative morbidity including low output syndrome (p less than 0.01) and respiratory (p less than 0.005) and neurologic (p = 0.06) complications.

Age Factors↗
PubMed1988

Indwelling transbronchial catheter drainage of pulmonary abscess.

Adequate cavitary drainage is of paramount importance in the treatment of pulmonary abscesses. Occasionally this cannot be achieved despite vigorous chest physical therapy and the utilization of bronchoscopy. Intermittent transbronchial catheterization under fluoroscopic guidance has been suggested as a method to facilitate drainage. We have modified this technique by placing an indwelling intracavitary catheter, which allows irrigation and drainage over a prolonged period. This report describes this technique and our experience with 3 patients managed in this fashion.

Adult↗
PubMed1988

The changing mortality of myocardial revascularization: coronary artery bypass and angioplasty.

The risk factors and outcome for the first 150 consecutive patients undergoing coronary artery bypass grafting (CABG) in 1985 (CABG '85) were compared with those of the first 150 patients undergoing CABG in 1975 (CABG '75) and those of the first 150 patients to have percutaneous transluminal coronary angioplasty (PTCA) in 1985 (PTCA '85). The CABG '85 patients had a significantly higher (p less than 0.05) incidence of known operative risk factors including advanced age, female sex, severity of angina, history of recent infarction, triple-vessel disease, left ventricular dysfunction, and emergency operation than the CABG '75 cohort. The clinical profile of the PTCA '85 patients closely resembled the low-risk profile found in the CABG '75 patients. Overall mortality following CABG more than doubled during the decade studied (3% versus 7%, p = 0.07). This study suggests that the increased mortality associated with CABG in 1985 is due in part to the inclusion of more high-risk patients in the surgical population. In addition, the application of PTCA removes low-risk patients from the surgical candidate pool and adds more patients requiring emergency operations, thereby further contributing to the overall decline in the clinical status of patients referred for operation.

Age Factors↗
PubMed1988

Bridging to cardiac transplantation with pulsatile ventricular assist devices.

As cardiac transplantation becomes more commonplace in the treatment of end-stage heart failure and as suitable donors become less available, an increasing number of patients will require mechanical circulatory assistance to bridge to transplantation. Since 1982, refractory hemodynamic instability requiring placement of pulsatile ventricular assist devices (VADs) has developed in 11 candidates for transplantation aged 24 to 54 years (mean, 39.6 years). A pneumatic Pierce-Donachy pump was used in 9 patients and an electrical Novacor pump in 2. The cause of the cardiomyopathy was ischemic in 6, postpartum in 2, idiopathic in 2, and doxorubicin hydrochloride toxicity in 1. Seven patients required left ventricular support (LVAD); 4 required biventricular mechanical support (BVAD). Duration of support ranged from 8 hours to 91 days with flows ranging from 4.1 to 8.5 L/min (mean, 5.5 L/min). Although hemodynamic stability was achieved in all 11 patients, contraindications to transplantation developed in 5 patients during VAD support (renal failure in 4, sepsis in 3, disseminated intravascular coagulopathy in 1). The remaining 6 patients (4 with an LVAD, 2 with a BVAD) remained good candidates for transplantation despite major complications in 5 (mediastinal bleeding in 3, driveline infection in 3, development of preformed antibodies in 2, small embolic stroke caused by device malfunction in 1). The 3 patients who were supported the longest (24, 75, and 91 days) were ambulatory while awaiting a donor heart. All 6 patients underwent successful transplantation after 8 hours to 91 days (mean, 24 days) of support. Other than one sternal wound infection, there were no major complications after transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗
PubMed1988

Coronary ostial stenosis.

From January 1970 to December 1986, 2.7% (228/8509) of all patients having coronary artery bypass grafting had atherosclerotic coronary ostial stenosis of 50% or more. There were 126 males (55%) and 102 females (45%) with mean ages of 60.2 +/- 9.0 and 59.2 +/- 10.2 years (P = NS), respectively. The left ostium was involved in 176 (77.2%) patients, the right in 41 (18.0%) and both in 11 (4.8%). Isolated ostial stenosis (no associated coronary disease of 50% or more) was present in 38/228 (17%) with females predominating (29/38, 76%). Isolated ostial stenosis occurred more frequently on the right (10/41, 25%) than on the left (18/176, 16%). Associated coronary disease occurred in a single vessel in 42 patients, in two vessels in 72 and in three vessels in 76 resulting in a mean of 2.0 diseased vessels per patient. If patients with isolated ostial stenosis are excluded there were 2.3 diseased arteries per patient. There were 687 grafts performed in these patients, an average of 2.3 grafts per patient. One month surgical mortality was 4.8% (11/228), but has been 2% (2/104) in the last 4 years. Nine of 27 late deaths were noncardiac with a mean follow-up of 49 +/- 44 months. Ostial stenosis is hemodynamically equivalent to left main disease when the left ostium is involved. Symptomatic ostial lesions, whether right or left, require operative therapy.

Adult↗
PubMed1988

Seven years' experience with the Pierce-Donachy ventricular assist device.

Of currently available methods for mechanical circulatory support, the Pierce-Donachy external pneumatic ventricular assist device has proved to be one of the most versatile and effective. Since 1981, 48 patients, aged 15 to 71 years (mean 43.0), with profound cardiogenic shock refractory to conventional therapy with drugs and intra-aortic balloon support, were supported with the Pierce-Donachy ventricular assist device. There were four patient groups. The largest group consisted of 30 patients with cardiogenic shock after cardiac operations. Nine required left ventricular support, six needed right ventricular support plus an intraaortic balloon pump, and 15 had biventricular support. Duration of support ranged from 3 hours to 22 days (mean 3.6 days). Eight of the first 11 patients died in the operating room of bleeding and/or biventricular failure. However, 16 patients, (53%) had improved cardiac function, 15 (50%) were weaned, and 11 (36%) were discharged. Of the last 19 patients, 47% survived. Frequent factors in nonsurvivors were myocardial infarction (75%) and renal failure (90%). Common complications in all patients were bleeding (52%) and infection (27%). The second group consisted of 11 patients with end-stage cardiomyopathy or acute myocardial infarction in whom the Pierce-Donachy ventricular assist device was used as a bridge to transplantation (left ventricular support, four patients; biventricular support, seven patients). Renal failure, infection, or coagulopathy that precluded transplantation developed in five patients. Five patients were supported for 8 hours to 75 days (mean 20.7 days) before undergoing successful transplantation, with one late death (six months) from rejection owing to noncompliance. One has subsequently undergone successful transplantation after 84 days of support. The third group consisted of four patients, aged 40 to 56 years (means 47.2), who had refractory cardiogenic shock after cardiac transplantation caused by pulmonary hypertension (two patients), hyperacute rejection (one patient), or graft failure (one patient). Despite biventricular support in all four (biventricular assist devices, two patients; right ventricular assist device plus intraaortic balloon pump, two patients), all died of infection and/or renal failure after 12 hours to 6 days (mean 3.4 days) of support. The final group consisted of three patients, aged 36 to 51 years (mean 45), with cardiogenic shock caused by acute myocardial infarction. One patient was supported with biventricular assist devices (3.5 days) and two patients were supported with a left ventricular assist device (8.5 and 15 days).(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1988

Effect of perioperative myocardial infarction on survival of postcardiotomy patients supported with ventricular-assist devices.

Ventricular-assist devices (VAD) have increased survival in patients with postcardiotomy shock, but the predictors of success need to be elucidated. We evaluated 45 patients treated with centrifugal (n = 18) or pulsatile (n = 27) VAD for postcardiotomy cardiogenic shock to determine the effect of perioperative myocardial infarction (PMI) on survival. The patients ranged in age from 15 to 72 years (mean age, 55.1 years). VAD support was left ventricular in 29, right ventricular in seven, and biventricular in nine, and the flow-rate range was 1.6-5.2 l/min (mean rate, 3.97 l/min) for 0.2-22 days (mean time, 4.1 days). PMI was determined by analysis of postoperative electrocardiogram (EKG), enzyme levels, or at necropsy. PMI was considered "possible" if there were either EKG or enzyme level changes, and "definite" if there were EKG and enzyme level changes or necropsy evidence. Of the 45 patients, 19 were successfully weaned from ventricular assistance; 12 were discharged (Group 1), and seven died (Group 2); the remaining 26 patients could not be weaned from VAD support (Group 3). In Group 1, one patient had a definite PMI, and three had a possible PMI. Among the 33 nonsurvivors (Groups 2 and 3), 24 patients had PMI by necropsy examination. Definite PMI was much more common in nonsurvivors (72.7%) than in survivors (8.3%) (p less than 0.05). However, Group 2 nonsurvivors were weaned despite PMI in 100% of cases. These data suggest that, although PMI is a strong negative determinant of survival in postcardiotomy patients, it cannot be considered a contraindication because it does not preclude myocardial recovery.

Adolescent↗
PubMed1988

Coronary artery bypass for recent infarction. Predictors of mortality.

The role of coronary artery bypass (CAB) surgery in patients with recent myocardial infarction remains controversial. To more clearly define the operative risks, we reviewed 336 patients who underwent isolated CAB within 30 days of infarction. There were 129 patients with stable or no angina (Group 1), 163 with angina at rest (Group 2), 21 with angina requiring intra-aortic balloon counterpulsation for pain control (Group 3), and 23 with severe postinfarction ischemia or extension complicated by cardiogenic shock (Group 4). There were 26 (7.7%) deaths overall. The mortality was 2.3% in Group 1, 6.1% in Group 2, 9.5% in Group 3, and 47.8% in Group 4. Univariate analysis (Student's t and chi 2 tests) and multivariate analysis (stepwise logistic regression model) were performed on 17 variables: age, gender, clinical Group (1-4), number of diseased vessels, presence of left main artery disease, left ventricular wall-motion score, left ventricular end-diastolic pressure, presence of mitral insufficiency, extent of infarction (subendocardial vs. transmural), interval from infarction to CAB, number of distal anastomoses performed, preoperative hemodynamic status, aortic cross-clamp time, and total cardiopulmonary bypass time. Only advanced age (p = 0.002), left ventricular wall-motion score (p = 0.004), and clinical group (p = 0.048) proved to be independent predictors of mortality by multivariate analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗