Pharmacokinetics of ofloxacin and levofloxacin for prevention and treatment of multidrug-resistant tuberculosis in children.

Limited data on fluoroquinolone pharmacokinetics and cardiac effects in children exist. Among 22 children receiving drug-resistant tuberculosis prophylaxis or treatment, serum concentrations following oral doses of levofloxacin (15 mg/kg of body weight) and ofloxacin (20 mg/kg) were lower than those expected from existing pediatric data, possibly due to differences in the formulations (crushed tablets). Drug exposures were lower than those in adults following standard doses and below the proposed pharmacodynamic targets, likely due to more rapid elimination in children. No QT prolongation was observed.

Repair of aortico-left ventricular tunnel associated with subpulmonary obstruction.

Aortico-left ventricular tunnel is a rare congenital cardiac defect. Because the tunnel traverses the upper portion of the interventricular septum, the potential exists for an aneurysmal tunnel to obstruct the outflow of the right ventricle. We report our clinical experience with such a patient, and emphasize the importance of a two-patch technique to avoid its occurrence.

Sydenham's chorea--analysis of 27 patients and a review of the literature.

The first documented epidemic of Sydenham's chorea was in 1418. In 1686 Thomas Sydenham was the first to describe the condition, but it was Richard Bright who in 1831 first made the association between chorea and rheumatic fever. Chorea is one of the major diagnostic criteria for rheumatic fever. Chorea is often considered a benign self-limiting condition. Little is known about the pathophysiological process. A link between the group A beta-haemolytic streptococcus through an antibody-mediated immune response targeting the basal ganglia has been described. Special investigations have been done to ascertain the pathophysiology, but none is of diagnostic value. The aims of this study were to analyse the clinical findings, the role of special investigations in the management and course of Sydenham's chorea and to review the literature. Data on 27 patients were analysed. Special investigations in these patients can be divided into those necessary to assist in diagnosing acute rheumatic fever and those to exclude other causes that mimic chorea. None of these tests was helpful in diagnosing chorea due to other causes; neither did they influence the management of these patients. In conclusion, Sydenham's chorea remains a clinical diagnosis and extensive and expensive special investigations are seldom warranted.

Secundum atrial septal defects - a review of 75 patients.

Secundum atrial septal defect (ASD) is the most common type of ASD within the spectrum of congenital cardiac abnormalities in children. In this retrospective study the data on 75 patients with a pure secundum ASD were analysed. The male/female ratio was 1:1,3. This is less than the reported male / female ratio, of 1:2. The symptoms most often found were shortness of breath, cough and susceptibility to fatigue. An ejection systolic heart murmur was found in the majority of the patients. A fixed split second heart sound was only found in 49% of patients. This could have been the result of incomplete documentation, inexperienced clinicians, a fast heart rate or the fact that a split second heart sound is not always present in patients with ASDs. On the chest radiograph the majority of patients presented with right ventricular enlargement, right atrial enlargement and increased pulmonary blood flow. A relatively unexpected finding on echocardiography was left atrial enlargement. This is usually caused by volume overload in the presence of large ASDs. Another unexpected finding was the high number of left QRS-axis deviations (10%) and indeterminate QRS-axis deviations, left rotation (7%) present on the electrocardiogram. This finding is much higher than the reported 3.8% of left QRS-axis deviation present in patients with secundum ASDs. The only explanation for this phenomenon is that during the embryological development of the atrial septum, not only does a secundum ASD develop, but the endocardial cushion becomes involved, giving rise to abnormal conductive pathways.

The influence of contrast media on serum osmolality, haematocrit and cardiac output. A comparative study in dogs.

Thirty-two mongrel dogs were used in a comparative study to assess the effect of normal saline solution, metrizamide and Cardioconray on serum osmolality, haematocrit and cardiac output. The study demonstrated that the higher the osmolality of the test substance, the greater the reduction in haematocrit and the higher the increase in cardiac output.

Cerebral oedema with coning in diabetic keto-acidosis. Report of 2 survivors.

Two children presented with a first episode of diabetic ketoacidosis. Initially both patients made a good clinical and biochemical recovery, but suddenly developed neurological signs consistent with a diagnosis of tentorial herniation. Cranial computed tomography showed signs of cerebral oedema in both cases with evidence of uncal and tentorial herniation in 1 patient, which resolved after the appropriate treatment. The excellent neurological outcome emphasises the need for early recognition and treatment of sudden onset brain oedema in diabetic keto-acidosis.

Mitral valve prolapse: a study of 45 children.

The knowledge pertaining to mitral valve prolapse is mainly based on studies in adults. In this study, the clinical profile as described in adults was compared with that found in children up to the age of 13 years. Forty-five children with echocardiographic-proven mitral valve prolapse and who met the inclusion criteria were included in the study. The male:female ratio in this study was 1:1.37 and was not statistically significantly different from reported ratios. Most of the children were asymptomatic. Twenty-one of the 31 patients referred from outside the hospital had an incidentally found murmur. The symptoms found in this study were not similar to those described in adults. The most commonly found symptoms were shortness of breath and fatigue, in contrast to those of chest pain and palpitations described in adults. Comparing males to females in this study, significantly lower weight (p = 0.005) and body mass index (p = 0.003) were found in girls, and a significantly lower pulse rate (p = 0.002) in boys. Left-sided cardiac enlargement was diagnosed in 11 patients on chest X-ray and in six patients on electrocardiogram. One patient had Marfan syndrome and four others had a Marfanoid appearance. In conclusion, most children with mitral valve prolapse are asymptomatic. Mitral valve prolapse is not an uncommon finding in children younger than 13 years of age. Patients with mitral valve regurgitation were advised to take infective endocarditis prophylaxis prior to invasive procedures.

Isolation of the left subclavian artery in tetralogy of Fallot and bronchial anomalies.

In the normal left-sided aorta, the vertebral arteries arise from the respective subclavian arteries. Isolation of the left subclavian artery takes place when the distal subclavian artery arises as an extension of a patent ductus arteriosus. This report describes a patient with tetralogy of Fallot and a right-sided aortic arch with isolation of the left subclavian artery. In addition, the patient also has congenital tracheal and bronchial stenosis, with a horseshoe lung.

Progressive familial heart block. Part I. Extent of the disease.

Progressive familial heart block (type I) has been identified in the RSA. Since 1977 many families have been referred for pedigree tracing. The present probands of some 9 pedigrees are the descendants of specific children of an immigrant; other genetic diseases appear in these pedigrees. The necessity of identifying, diagnosing and possibly treating the descendants of carriers is emphasized.

Progressive familial heart block. Part II. Clinical and ECG confirmation of progression--report on 4 cases.

Two types of progressive familial heart block controlled by a single gene have been described; 4 cases show that type I is progressive and that the pathogenesis is still unknown.

Supraventricular tachycardia in children.

The mechanisms causing different supraventricular tachycardias can be identified with the aid of the 12-lead ECG using Tipple's approach. The main aims of this retrospective study were to use the 12-lead ECG to determine the underlying mechanisms of supraventricular arrhythmias and to evaluate the effectiveness of the treatment modalities used. Forty-one patients were included in the study. The main findings were: nine of the 41 patients had atrial tachycardias while junctional tachycardia occurred in 32/41 of our patients. The underlying mechanisms causing the junctional tachycardias were: AVNRT (n = 21), AVRT (n = 10) and JET (n = 1). Of the 10 patients presenting with AVRT, eight were less than one year old. AVNRT occurred more often in the older age group (>1 year of age). Fifteen of the 41 patients had spontaneous cessation of their supraventricular tachycardia. The drug most commonly used during the acute and long-term phases was digoxin. Amiodarone was used in six patients with an 80% success rate. In the early 80s verapamil was used in five patients with a 100% success rate. It is important to note that verapamil is no longer used in children due to its side effects. Lately, adenosine phosphate is the drug of choice in most supraventricular tachycardias. The management of supraventricular tachycardias in paediatric practice is mainly based on clinical studies and individual experience. Care must therefore be taken to choose medication regimens that are likely to be effective with the minimum risk of potentiating abnormal haemodynamics or conduction.

Factors influencing successful closure with indomethacin of the patent ductus arteriosus in premature infants.

The incidence of persistent patency of the ductus arteriosus (PDA) is inversely related to birth weight. A PDA contributes to pathological conditions in the neonate and timely closure in these low-L birth-L weight infants could potentially prevent these complications. Prostaglandin inhibition with indomethacin is one treatment strategy currently available. This retrospective descriptive study evaluated the parameters that influenced the effectiveness of indomethacin in closure of the PDA in 101 consecutive premature infants and the adverse effects of indomethacin in these infants. Independent variables found to increase the risk of unsuccessful closure with indomethacin significantly were caesarean section, lower haematocrit at delivery and severity of hyaline membrane disease. Non-L closure also resulted in prolonged ventilation. No significant adverse effects were recorded in the infants who received indomethacin but neonatal jaundice was more common in those infants who responded to indomethacin.

Diagnosis of haemodynamically significant patent ductus arteriosus in neonates-- is the ECG of diagnostic help?

The presence of a haemodynamically significant patent ductus arteriosis (PDA) in the premature newborn may contribute to the development of brochopulmonary dysplasia, intraventricular haemorrhage and necrotising enterocolitis. It is therefore essential that the diagnosis of such a PDA be made in time in order to intervene medically or surgically. Echocardiography is at present the prime diagnostic tool, but it is mainly available in tertiary hospitals. Chest roentgenography is of little diagnostic value especially in the presence of respiratory disease, which is often present in premature babies. Very little is known about the diagnostic value of the electrocardiogram (ECG) in premature babies. The aim of this study was to describe the standard 12-lead ECG findings in low-birth-weight babies with haemodynamically significant PDAs. Thirty-two babies with haemodynamically significant PDAs, as established by echocardiography, were included in the study. Standard 12-lead ECGs were done in all these babies. In 15 patients ECG abnormalities were found; only 22% had left atrial and left ventricular enlargement indicative of significant left-to-right shunting, while 78% had no ECG changes indicative of left-to-right shunting. In conclusion, the ECG cannot be used to identify haemodynamically significant PDAs.

An explanation of the unusual electrocardiographic findings in a patient with pulmonary agenesis and dextrocardia.

Interpretation of the electrocardiagram (ECG) is extremely helpful in distinguishing between the different forms of dextrocardia. The patient in this report had agenesis of the right lung and dextroposition; the ECG mimicked mirror-image dextrocardia, with elements of dextroversion also present.

Cardiac tamponade following umbilical vein catheterisation in a neonate.

Umbilical vein catheterisation (UVC) should not routinely be used in the neonatal intensive care unit, and when it is used special precautions should be taken and guidelines followed. We present an unusual complication which occurred following use of an umbilical vein catheter in a term neonate. This case highlights another potentially lethal complication of UVC, and emphasises the risks associated with the procedure. In order for the benefits of UVC to outweigh the risks, certain guidelines are reviewed. The importance of confirming the position of the catheter tip with both anteroposterior and lateral radiographs is emphasised.

Second-degree atrioventricular heart block after doxapram administration.

Doxapram, a respiratory stimulant, is used to treat idiopathic apnea of prematurity. The side effects reported are minimal. We present three cases of second-degree atrioventricular block caused by QT interval prolongation associated with doxapram administration. All three infants returned to normal sinus rhythm after doxapram administration was stopped.

The need to repeat lumbar puncture.

Four patients with bacterial meningitis are reported. On initial examination 1 patient had a slightly abnormal cerebrospinal fluid (CSF), and in the other 3 patients the CSF was completely normal. An obviously purulent CSF was obtained when lumbar puncture was repeated 14-48 hours later. All 4 patients presented initially with pyrexia, and either neck stiffness or convulsions. In 3 of the 4 patients a cause for pyrexia was found on initial examination but lumbar punctures were done for neck stiffness or convulsions to exclude meningitis. The problems and the need to repeat a lumbar puncture, as well as the importance of blood cultures in a patient with suspected meningitis, are discussed. The fact that a normal specimen of CSF does not exclude meningitis is stressed.

Progressive familial heart block (type I). A follow-up study after 10 years.

A follow-up study was done on 55 patients, all members of families with type I progressive familial heart block (PFHB) examined during 1977. Of the 55 patients 5 had died, 17 had normal ECGs while 7 with previously abnormal ECGs remained unchanged. All the others had progressed to a more severe form of heart block and 8 of them had received permanent pacemakers. These findings again emphasize the importance of regular ECG follow-up examinations of members of PFHB families.

[The correlation between ECG characteristics and hemodynamic results in isolated atrial septal defects]. / Die korrelasie tussen EKG-eienskappe en hemodinamiese gevolge van geïsoleerde atriale septale defekte.

Electrocardiographic characteristics and haemodynamic findings in 30 patients with secundum atrial septal defects were correlated retrospectively to determine whether any haemodynamic deductions could be made based on ECG findings. Although statistically significant correlations were found, no accurate haemodynamic estimations could be made based on ECG findings.