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Biomedical subjects

K Turley

Publications and source records attributed to K Turley.

At least 37 records · Page 2Linked to original sources
PubMed1990

Iodine toxicity secondary to continuous povidone-iodine mediastinal irrigation in dogs.

Mediastinitis is a devastating complication following median sternotomy. Continuous povidone-iodine (PVP-I) irrigation has been advocated as therapy because of its broad antimicrobial spectrum and its apparent safety. However, several recent clinical reports have warned of suspected local and systemic iodine toxicity. The purpose of this study is to determine if significant amounts of iodine can be absorbed systemically via the mediastinum, and if so, what toxicity (local and/or systemic) may result. PVP-I (0.5%) was continuously irrigated into the pericardial sacs of three dogs via catheters for 48 hr. Serial serum and urine iodine levels were determined. The serum steady-state concentration (Css), the rate elimination constant (k), the urinary clearance (Cl), and the serum half-life (t 1/2) for iodine were assessed. Serum electrolytes, Bun, Cr, and arterial pH were measured to assess systemic iodine toxicity. Tissue samples of the heart, pericardium, liver, and kidney were examined histologically for evidence of local or end-organ iodine toxicity. This study demonstrated that the absorption of iodine during continuous mediastinal irrigation with PVP-I follows zero-order pharmacokinetics, just as if it were being given by continuous intravenous infusion. The baseline serum iodine concentration was 145.9 +/- 64.3 micrograms/dl, Css was 29,290 +/- 101.4 micrograms/dl, k was 0.0996 +/- 0.009/hr, Cl was 872.4 +/- 119.3 ml/hr, and t1/2 was 6.22 hr. Urinary excretion of iodine increased in proportion to the serum iodine. Measured serum chloride increased in a linear manner (r = 0.949), while serum Na, K, Bun, Cr, and pH were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗
PubMed1990

Intraoperative echocardiography in infants and children with congenital cardiac shunt lesions: transesophageal versus epicardial echocardiography.

To determine the utility and limitations of intraoperative transesophageal echocardiography in infants and children with congenital intracardiac shunts, intraoperative transesophageal (n = 50) and epicardial (n = 49) echocardiograms were performed before and after cardiopulmonary bypass in children from 4 days to 16 years old and 3 to 45 kg in body weight. A miniaturized transesophageal probe (6.9 mm maximal diameter) was used in 36 patients weighting less than or equal to 20 kg. Epicardial imaging was performed with a 5 MHz precordial probe. The intraoperative transesophageal echocardiographic findings before and after cardiopulmonary bypass were correct and complete in 94% of patients. Transesophageal echocardiography correctly identified atrial septal defects, most types of ventricular septal defects, anomalous pulmonary veins, atrioventricular septal defects, tetralogy of Fallot, truncus arteriosus and double inlet ventricles. It failed to provide a correct diagnosis in only three patients, all of whom had doubly committed subarterial ventricular septal defects. Epicardial echocardiography identified all cases that had a doubly committed subarterial ventricular septal defect. A correct and complete intraoperative diagnosis was obtained with the use of epicardial imaging in 92% before and after cardiopulmonary bypass, but this technique required interruption of surgery and could not be completed in three patients because of induced arrhythmias and hypotension. These results demonstrated that intraoperative transesophageal echocardiography consistently defined important morphologic, color and pulsed Doppler ultrasound features of most congenital shunt lesions. Lesions that involved the right ventricular outflow tract are sometimes difficult to image with uniplane transesophageal echocardiography. There were no complications in any of the 50 subjects.

Cardiopulmonary Bypass↗
PubMed1990

Neonatal aortic stenosis.

Aortic stenosis in the neonate has been associated in the past with a high operative mortality. As a result, in the current era of percutaneous balloon dilatation, the optimal mode of therapy remains controversial. An approach of stabilization with cardiopulmonary bypass, followed by relief of left ventricular outflow tract obstruction, was used at three institutions, and the results are presented. During the period 1983 to 1989, 40 neonates with isolated aortic stenosis and patent ductus arteriosus or coarctation of the aorta, or both, underwent operative therapy. Ages ranged from 1 to 30 days, median of 12 days, including 17 patients in the first week of life. There were 30 boys and 10 girls; weights ranged from 2.5 to 5.5 kg with a mean of 3.6 kg. Perioperative conditions included congestive heart failure in 38 and mitral regurgitation in 16; left ventricular-aortic gradients ranged from 15 to 130 mm Hg, with a mean of 67 mm Hg. There were 30 open valvotomies and 10 transventricular dilatations. The hospital survival rate was 87.5% (35/40) with no significant difference between the methods of valvotomy (9/10 in the transventricular dilatation group, 90%; 26/30 in the open valvotomy group, 87%). Although multiple methods of perfusion and valvotomy were used, the single unifying factor of cardiopulmonary bypass stabilization was present in all 40 patients. No significant difference in survival was noted between institutions, methods of cardiopulmonary bypass, cardiopulmonary bypass times, crossclamp times, or method of valvotomy. There have been five reoperations, with one late death in a patient requiring mitral valve replacement and an apical-aortic conduit. One sudden death occurred; autopsy revealed endocardial fibroelastosis. Results demonstrate that in the three institutions using the methods described, a high operative and late survival rate is possible. The results of this technique, against which percutaneous dilatation should be compared, are standard in the current era.

Aortic Valve↗
PubMed1989

Effect of surgical blood loss and volume replacement on antibiotic pharmacokinetics.

Antibiotic prophylaxis is used widely to prevent postoperative infection associated with cardiac operations. The influence of perioperative blood loss on antibiotic pharmacokinetics has not been well studied. Plasma cefazolin sodium samples from 8 patients undergoing a cardiac operation were collected postoperatively and analyzed. The results suggest that blood loss has a minimal effect on the elimination of cefazolin and that therapeutic concentrations are maintained without altering the dosage regimen.

Aged↗
PubMed1989

Aortic allografts: reconstruction of right ventricle-pulmonary artery continuity.

The use of aortic allografts in the repair of congenital cardiac lesions has increased as a result of both the advent of cryopreservation and the effects of increased donor availability secondary to infant transplantation. During the period 1986 through 1987, 38 cryopreserved aortic allografts were placed for right ventricle-pulmonary artery discontinuity. Size of the allografts ranged from 11 to 26 mm (mean size, 19 mm), and age of the patients ranged from 6 weeks to 26 years (mean age, 5 years). Twenty-one patients had primary placement of aortic allografts, and 17 underwent replacement of previous conduits. There were 5 hospital deaths (13%) overall, only 1 among the 10 patients younger than 6 months of age with truncus arteriosus, and none among the 17 patients having conduit replacement. A large conduit could be placed with a low incidence (10.5%) of postoperative hemorrhage related to the conduit. The aortic allograft is our conduit of choice for both conduit replacement and primary repair of right ventricle-pulmonary artery discontinuity.

Adolescent↗
PubMed1989

Systemic-to-pulmonary artery shunt using the internal mammary artery.

Systemic-to-pulmonary artery shunts may be useful for palliation of cyanotic congenital heart disease. We report the case of a 5-year-old boy in whom the internal mammary artery was used to create a systemic-to-pulmonary artery shunt after failure of a previous Blalock-Taussig shunt. This technique may have distinct advantages in selected cases and should be considered as an alternative during investigation of the older child who requires a systemic-to-pulmonary artery shunt.

Anastomosis, Surgical↗
PubMed1989

Lord Brock--the direct approach.

The contributions of Sir Russell Brock to the early development of cardiac surgery are multiple. However, one of the most telling was his description of 3 cases of pulmonary stenosis in 1948 treated by direct transventricular valvulotomy. His subsequent treatise, The Anatomy of Congenital Pulmonary Stenosis, published in 1957, outlined this direct approach to cardiac lesions, a philosophy commonly adopted in modern care of cardiac lesions and a major contribution to cardiac surgical thinking.

Cardiac Surgical Procedures↗
PubMed1989

Diagnosis of coronary artery fistula by two-dimensional echocardiography, pulsed Doppler ultrasound and color flow imaging.

Ten consecutive patients with a coronary artery fistula, aged 1 day to 4 years, were studied by two-dimensional echocardiography, pulsed Doppler ultrasound and color flow imaging. All patients underwent cardiac catheterization, and seven patients had surgical closure of the fistula. The origin, course and site of drainage of the coronary artery fistula were correctly identified prospectively by echocardiographic examination in all patients. Color flow imaging was particularly helpful in visualizing the site of drainage of the fistula. Diameters of the right and left coronary arteries at their origin and of the aortic root were measured from two-dimensional echocardiographic frames and compared with measurements obtained in normal children. The ratio of coronary artery diameter to aortic root diameter in normal children was 0.14 +/- 0.03 (mean +/- SD) for the right coronary artery and 0.17 +/- 0.03 for the left coronary artery. These normal ratios were greatly exceeded for coronary arteries feeding the fistula, and ranged from 0.68 to 0.84 for the right coronary artery and from 0.34 to 0.52 for the left coronary artery. All anatomic information needed for surgical treatment of coronary artery fistula was consistently obtained by echocardiography with color flow imaging. The fistula was closed from within the heart in five patients and by ligation from the epicardial surface in two patients. In these latter patients, intraoperative color flow imaging at the time of ligation proved to be extremely valuable in achieving complete closure.

Cardiac Catheterization↗
PubMed1989

Surgery of right-sided endocarditis: valve preservation versus replacement.

Surgical treatment of right-sided endocarditis has in the past been centered on valve resection or resection with valve replacement. From 1981 to 1989, we attempted tricuspid valve repair in 19 patients with right-sided endocarditis. Fourteen of these were successful. The methods of valve repair and classification of the lesions that allow evaluation for repair are discussed, including the use of transesophageal echo and a hand-held color Doppler unit for intraoperative assessment.

Echocardiography↗
PubMed1988

The fate of the 12 mm porcine valved conduit from the right ventricle to the pulmonary artery. A ten-year experience.

The 12 mm Dacron conduit containing a porcine valve is the smallest valved conduit manufactured and is used in the youngest infants with the most diminutive pulmonary arterial system. The outcome of patients with such a conduit is unknown. Between 1975 and 1985 there were 49 hospital survivors after placement of a 12 mm extracardiac valved conduit from the right ventricle to the pulmonary artery. Follow-up is available in 42 patients, aged 1 to 16 months (mean 3.5) and weighing 2.5 to 8.7 kg (mean 3.8). Twenty-eight patients (67%) have undergone subsequent conduit replacement, and 11 (26%) are alive and asymptomatic with a mean follow-up of 56 months. There were three late deaths. The interval between implantation and conduit change was 4.5 to 101 months (mean 44), allowing a weight gain of 2.7 to 23 kg (mean 10.4) before reoperation at age 12 to 117 months (mean 49). Despite elevated right ventricular pressures equaling systemic values, 37% of these patients were clinically asymptomatic. The gradient across the 12 mm valved conduit before explantation ranged from 30 to 173 torr (mean 83) with an almost equal predilection for stenosis at the proximal anastomosis, valve, conduit, distal anastomosis, and main pulmonary artery. The intervening pulmonary artery growth determined the size of the replacement conduit, 14 to 25 mm (mean 16), and was the main factor influencing the results of reoperation. This study demonstrates that the 12 mm porcine valve-containing conduit affords palliation in this difficult subset of patients with the smallest pulmonary arterial tree.

Bioprosthesis↗
PubMed1988

The Mustard procedure in infants (less than 100 days of age). Ten-year follow-up.

Surgical treatment of transposition of the great arteries and intact ventricular septum has changed markedly in the past 10 years. However, long-term follow-up on new approaches is not available. In a unique group of patients, operated on in the first 100 days of life with the Mustard procedure, such follow-up is available, and the results of these true infant repairs represent a benchmark against which subsequent techniques applied to infants should be compared. During the period of 1975 to 1980, 36 infants, less than 100 days of age, who had transposition of the great arteries and intact ventricular septum, underwent Mustard repair at the University of California, San Francisco. Ages ranged from 4 to 98 days (mean 46 days) and weights from 2.3 to 6.6 kg (mean 3.5 kg). There were no early deaths, and late follow-up was available from 8 to 13 years (mean 10 years). The late survival rate was 97% (mean 10 years). There was a 62% rhythm disturbance-free survival rate, 89% reoperation-free survival rate, and 91% pacemaker-free survival rate. Echocardiographic evaluation revealed obstruction of the superior vena cava in eight patients, tricuspid insufficiency in four, right ventricular dysfunction in two, and left ventricular outflow tract obstruction in three. The Mustard procedure, performed in the first 100 days of life, results in a high rate of survival (early 100% and late 97%, at a mean of 10 years) and a low incidence of late complications against which other techniques of infant repair should be compared.

Echocardiography↗
PubMed1987

Infant total anomalous pulmonary venous connection: factors influencing timing of presentation and operative outcome.

The surgical experience in 75 patients with total anomalous pulmonary venous connection (TAPVC) between 1975 and 1986 was reviewed. Most of these patients underwent operation at less than 1 month of age (39 of 75, 52%). Operative approaches used were the standardized left-sided approach for supracardiac and infracardiac TAPVC, reserving transatrial repair for only the intracardiac lesions. Cardiopulmonary bypass was managed by deep hypothermia and circulatory arrest in 16 of 75 (29%) and continuous hypothermic bypass with low flow was used for the remaining 59 of 75 (71%). Operative policy included maintaining patency of existing patent ductus (1 patient) and atrial (4 patients) or ventricular (3 patients) defects to allow additional shunting in cases of severe obstruction. Operative mortality was 9.3% (7 of 75) and late mortality was 6.7% (5 of 75). The determinants of operative deaths were (1) the type of TAPVC (highest rates in types III and IV with 3 of 17 or 19%, and 2 of 8 or 25%, respectively) and (2) associated severe preoperative pulmonary-to-systemic venous obstruction. Determinants of late death were (1) residual pulmonary-to-systemic obstruction (two patients type III and 1 patient type I), and (2) associated intracardiac lesions (two patients type IV with atrioventricular canal). In summary, the timing of corrective surgery and outcome are influenced by the clinical condition of the infant as a direct reflection of the anatomic type and severity of associated lesions.

Age Factors↗
PubMed1986

Noninvasive evaluation of suspected thoracic aortic disease by contrast-enhanced computed tomography.

Traditionally, suspected thoracic aortic disease has been evaluated by aortography, which has associated risks because it is invasive. With the introduction of computed tomography (CT), a noninvasive alternative has become available. In the present retrospective study, the potential clinical value of CT in providing correct diagnoses and pertinent information required for current therapies is evaluated. For this purpose, results of CT in 200 patients examined for suspected thoracic aortic disease were compared with "hard" (surgical and autopsy findings) or "soft" (follow-up clinical information) evidence of the true diagnoses. Aortographic results, available in 51 patients (26%), were also compared with available clinical evidence. Excluding inadequate examinations, the diagnostic accuracy of the independently and blindly interpreted results of CT and aortography were similar (86% and 87%, respectively) in patients with true diagnoses confirmed by hard evidence. When patients evaluated for aortic damage from acute blunt chest trauma were also excluded, the accuracy was 90% for CT and 86% for aortography. Specifically, CT was 83% and 67% accurate in proved (i.e., confirmed by hard evidence) type A and type B dissections, respectively (75% for both type A and B by aortography). In the 183 patients suspected of having thoracic aortic disease not attributable to acute blunt chest trauma and with follow-up information, 91% would have been managed appropriately based on their CT evaluation alone. In the subset of patients who underwent aortographic evaluation as well, 91% would have been managed appropriately based on aortography alone. The accuracy for combined CT and aortography was 94%.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Dissection↗
PubMed1986

Infant coarctation: a spectrum in clinical presentation and treatment.

Between 1975 and 1985, 125 infants 2 to 365 days old (majority, 30 days old or less) with coarctation of the aorta underwent surgical repair. Forty-seven patients (38%) had severe congestive heart failure (CHF), metabolic acidosis, and poor systemic perfusion. The predominant operative technique was synthetic patch aortoplasty (100 patients); the remaining 25 had an end-to-end anastomosis. There were no operative deaths. Perioperative complications were minimized with the synthetic patch technique (less than 15%). For patients surviving at least 3 months after repair, the arm-leg systolic blood pressure gradient was relieved in 82% (71/87) of the patients having patch aortoplasty versus 65% (15/23) of the patients with end-to-end anastomosis. Although the rate of reoperation between the two groups was similar (patch, 5 [6%]; end-to-end, 3 [13%], two of the reoperations in the patch group were for preexisting hypoplastic transverse aortic arch. Late deaths (20 patients, 16%) were due to other major associated cardiac anomalies. Patch aneurysms have not occurred. Expedient use of synthetic patch aortoplasty has decreased perioperative complications, relieved coarctation gradients for CHF, increased early survival even in the presence of complex or associated cardiac anomalies, and has an acceptable rate of recurrent coarctation (6 to 13%).

Aortic Coarctation↗
PubMed1986

Aspirin anticoagulation in children with mechanical aortic valves.

The optimal method of anticoagulation in children with mechanical heart valves is controversial. Between 1975 and 1986, aspirin or aspirin with dipyridamole has been used for anticoagulation in children receiving a mechanical aortic valve at the University of California, San Francisco. Fifty-one patients (ages 1 to 23 years, mean 12.9 years) were treated with aspirin (n = 45) or aspirin with dipyridamole (n = 6) and observed a mean of 36.5 months (range 3 to 100 months). There were four late deaths: two from endocarditis and two from other medical problems, but none related to thrombosis or embolus. Follow-up was accomplished by direct contact with the patient, parent, or referring physician. Two patients (3.9%) were lost to late follow-up. One minor neurologic event occurred perioperatively and resolved spontaneously. There were no postoperative thromboembolic events. Eleven asymptomatic children were recently studied by magnetic resonance imaging or computed axial tomography of the brain and had no evidence of prior silent cerebral thromboembolic defects. There were four patients (5.9%) who had minor hemorrhagic complications: Three patients had nosebleeds and one patient had an upper gastrointestinal hemorrhage. Five patients were changed to warfarin anticoagulation: the patient with upper gastrointestinal hemorrhage and four older patients because of physician preference, all after uncomplicated aspirin therapy. There were no mechanical valve failures, although one patient required reoperation 9 months later for perivalvular leak. All children have remained in normal sinus or paced rhythm during follow-up. These results show that children with mechanical aortic valves in normal sinus rhythm can be safely treated with aspirin (or aspirin with dipyridamole) with little risk of thromboembolic events, valve thrombosis, or valve failure. Hemorrhagic complications resulting from aspirin are minor and easily treated.

Adolescent↗
PubMed1985

Iodine toxicity in a patient treated by continuous povidone-iodine mediastinal irrigation.

Continuous povidone-iodine irrigation is frequently used to treat mediastinitis after median sternotomy and has been considered safe and effective. We describe a 34-month-old patient with mediastinitis after median sternotomy who was treated with continuous povidone-iodine irrigation and who absorbed toxic quantities of iodine (total serum iodine, 9,375 micrograms/dl; normal range, 4.5 to 9.0 micrograms/dl). An unexplained metabolic acidosis developed, along with changes in mental status, and the patient died. This experience and a thorough review of the literature lead us to believe that continuous povidone-iodine irrigation of the mediastinum is contraindicated.

Acidosis↗
PubMed1985

Changes in the respiratory gas tensions of a pneumonectomy space and their application to the diagnosis of bronchopleural fistula.

The oxygen (pO2) and carbon dioxide (pCO2) gas tensions of a pneumonectomy space were studied in an animal model. The 2 gases were measured in a standard blood gas analyser. The space gas pO2 and pCO2 equilibrated to a steady state within 48 hours of thoracotomy (pO2 mean 53.9 +/- 9.3 SD torr; pCO2 mean 44.8 +/- 9.9 SD torr). In the presence of a bronchopleural fistula (BPF), the pO2 rose significantly (mean pO2 118.4 +/- 13.2 SD torr; p less than 0.001). The space pCO2 usually fell, but the response was inconsistent (mean pCO2 33.6 +/- 16.4 SD; p = NS). A further rise in space pO2 could sometimes be induced by allowing the animals to breathe 100% oxygen by face mask. Data from 4 clinical cases of BPF support the concept that measurement f the space gas pO2 could be used as a bedside test for BPF.

Animals↗