George Benzing

Glucose and insulin changes in infants and children undergoing hypothermic open-heart surgery☆

Marked hyperglycemia was observed in patients undergoing hypothermic open-heart surgery. To evaluate potential mechanisms responsible for hyperglycemia, paired samples were evaluated for glucose and insulin levels in 3 groups of patients. Group 1 consisted of 8 patients less than 2 years of age undergoing cardiac surgery requiring total circulatory arrest; Group 2 consisted of 9 patients less than 2 years of age undergoing open-heart procedures but not requiring total circulatory arrest; Group 3 consisted of 10 patients greater than 2 years of age, none of whom required total circulatory arrest. All 3 groups had striking hyperglycemia during cardiac surgery and in the first few hours after the operation. Despite elevated glucose levels during surgery, insulin levels failed to increase proportionately in response to hyperglycemic stimulus. Subsequently, in a fourth group of 10 patients less than 2 years of age not undergoing total circulatory arrest, the amount of glucose infused was restricted and they did not have hyperglycemia. In children, osmotic diuresis resulting from hyperglycemia after open-heart surgery may be misinterpreted as an index of satisfactory cardiorenal performance. Accordingly, it is recommended that the diluent added to the pump blood prime solution contain no supplemental glucose; also, intraoperative fluid should consist of a balanced electrolyte solution but no glucose.

Fiber Embolization — A Hazard of Cardiac Surgery and Catheterization

DURING the past 10 years, we have observed that anisotropic intra-arterial fibers, similar to cotton or cellulose libers, are a common incidental finding in pathological specimens, found almost exc...

Prolonged myasthenic syndrome after one week of muscle relaxants.

A child developed severe, generalized muscle weakness which persisted for 6 weeks, after receiving muscle relaxants for 1 week while requiring ventilator support. Electrodiagnostic studies indicated a presynaptic disorder of the neuromuscular junction which improved with high-frequency stimulation, similar to findings in Lambert-Eaton syndrome. Muscle specimens exhibited neurogenic targetoid fiber atrophy. Ultrastructure of the neuromuscular junction indicated terminal axon degeneration and atrophy with depletion of the secretory vesicles. Most reported patients with post-ventilator paresis have received steroids and muscle relaxants; muscle weakness commonly has been brief and attributed to steroids. We believe that this reversible myasthenic syndrome probably represents neurotoxicity due to high doses of steroidal nondepolarizing blocking agents; however, available data are insufficient to resolve this controversy.

Complications Following Homograft Replacement of the Right Ventricular Outflow Tract

Abstract Twenty-two patients who had surgical reconstruction of the pulmonary artery and right ventricular outflow tract with a complete or partial valve-bearing aortic homograft have been followed for 1 to 5 years. The following complications were noted: (1) calcification of the homograft (10 patients; noted within the first postoperative year in 6 patients and 2 to 4 years after operation in the remaining 4); (2) pulmonary valve insufficiency (12 patients, including 8 with complete three-cusped aortic homografts); (3) residual obstruction (4 patients), primarily at the distal anastomosis; and (4) sudden, unexpected death (1 patient), which occurred 18 months after operation from rupture of the right ventricular outflow tract. Although the immediate postoperative results with aortic homografts are good, late complications are frequent. We have concluded that aortic homografts are not ideal for right ventricular outflow tract reconstruction. Further development and evaluation of a suitable valve-bearing prosthesis is necessary since the goals of reconstruction in this group of patients continue to be relief of obstruction and establishment of a functionally competent right ventricle-to-pulmonary artery conduit.

Group C streptococcal sinusitis

The group C streptococci have emerged as important human pathogens. A case of group C streptococcal sinusitis in a 6-year-old girl is reported and four cases of group C streptococcal sinusitis are reviewed. Age less than 18 years, central nervous system complications, and a delay in the institution of adequate therapy were features common to all five cases. Three patients were bacteremic with group C streptococci and two patients died. These cases suggest that when beta-hemolytic streptococci are isolated from sinus culture, serogrouping should be performed. When group C streptococci are identified, appropriate antimicrobial therapy should be instituted and one should be alert for suppurative intracranial complications.

Iatrogenic Horner's syndrome

Abstract Recent reports appear to indicate that the incidence of iatrogenic Horner s Syndrome is increasing, perhaps due to an increased frequency of surgical procedures, anesthetic techniques, and vascular access methods applied to the cervical region. A case of Horners syndrome, due to a malpositioned thoracostomy tube, is described and iatrogenic causes of Horners syndrome are discussed.

Cardiac Performance and Oxygen Consumption during Intracardiac Operations in Children

Cardiac performance and oxygen consumption in 30 patients undergoing surgical treatment for congenital cardiac disease were determined from intraoperative measurements. Arterial pressure, cardiac index, mean left ventricular hydraulic output power, pulmonary artery oxygen saturation were obtained at average mean left atrial pressures of 8.1 and 15.2 cm H2O after cardiopulmonary bypass in 20 patients. These same variables were measured at an average pulmonary artery saturation of 65 and 75% in 30 patients. A composite of measurements of cardiac performance was desirable to guide precise patient care intraoperatively, especially if myocardial function was compromised. It is suggested that left atrial pressure be maintained at a level that results in a pulmonary artery saturation greater than 65%.

Low-cost daily pacemaker monitoring system.

To reduce the cost of pacemaker monitoring, we developed an inexpensive cardiac pacemaker interval monitor that detects electromagnetic radiation of the electrical pulse generated by an implanted pacemaker. The pulse interval is timed by logic systems and a piezoelectric crystal. Pulse interval is computed to the nearest 0.1 msec. The device is battery powered and can be used at home by the patient to monitor pulse interval daily with little cost after the initial expenditure. The unit may also be used by the physician to detect the stability or constancy of random variation of the pulse interval. From a daily record of measurements of the pulse interval, limits are set by the physician to predict impending battery exhaustion. Eight patients have been monitored for up to 24 months.

Basic Pediatric Electrocardiography

The author, Arno Hohn, MD, is professor of pediatrics and director of pediatric cardiology at the Medical University of South Carolina. From his 20 years of teaching experience, Dr. Hohn has described electrocardiography in a simple, straightforward presentation designed for the medical student, house staff officer, general practitioner, or pediatrician who desires to interpret the electrocardiograms of children. This point is evident from the double-spaced printing and undercrowding of pages. The book is divided into three parts that are concerned with general concepts of electrophysiology, the ECG in pediatric conditions, and arrhythmias. The treatise begins with a description of the electrical impulses generated within the heart and lead systems. Normal and abnormal ECG wave forms and electrical axis are illustrated and discussed. Principles of the vectorcardiogram are explained and correlated with the standard ECG. Although interpretation of the vectorcardiogram may seem to be a giant step for the neophyte, the

The Clinical Recognition of Congenital Heart Disease.

This book is written about congenital heart disease as observed in the pediatric and adult age groups. Most of the emphasis is placed on the clinical features of the relatively pure forms of cardiac anomalies, not the complex. The treatise is divided into 31 chapters, each concerned with a type of heart defect. The chapters begin with an introductory note about the anatomy of the disorder. This is followed by a characterization of the incidence, natural history, and symptoms peculiar to the defect. Then the author presents an elucidative description of the physical appearance of the patient, arterial pulse, venous pulse, precordial movement, and auscultatory findings. When appropriate the author has included illustrations of phonocardiograms, pressure recordings, and electrocardiograms. He explains the underlying concepts concerning the timing of heart sounds, configuration of recorded murmurs, and pressure wave changes. There are many reproductions of chest roentgenograms and angiocardiograms. This book presents