Perinatal stimulation and adaptation of the neonate

The present report describes psychobiological studies of behavior around the time of birth. An adaptive, ecological perspective is presented in which stimulation of the fetus and newborn is purported to instigate adaptive postpartum behavior. Studies describing the perinatal sensory environment are reviewed, with a consideration of emergent sensory function of the fetus. It is asserted that afferent input associated with parturition perturbs the fetus and neonate, producing a general arousal state that facilitates breathing, suckling, and early learning. The view developed herein is that perinatal sensory input induces and canalizes the newborn's behavior, thereby regulating adaptive postpartum function. Deviations in afferent input may alter ontogenetic trajectories and compromise developmental outcome by reducing availability of conditions necessary for adequate postpartum adaptation.     

Cardiac abnormalities in end stage renal failure and anaemia

Thirteen anaemic children on dialysis were assessed to determine the incidence of cardiac changes in end stage renal failure. Nine children had an increased cardiothoracic ratio on radiography. The electrocardiogram was abnormal in every case but no child had left ventricular hypertrophy as assessed by voltage criteria. However, left ventricular hypertrophy, often gross, was found on echocardiography in 12 children and affected the interventricular septum disproportionately. Cardiac index was increased in 10 patients as a result of an increased left ventricular stroke volume rather than heart rate. Left ventricular hypertrophy was significantly greater in those on treatment for hypertension and in those with the highest cardiac index. Abnormal diastolic ventricular function was found in 6/11 children. Children with end stage renal failure have significant cardiac abnormalities that are likely to contribute to the high cardiovascular mortality in this group. Anaemia and hypertension, or its treatment, probably contribute to these changes. Voltage criteria on electrocardiogram are of no value in detecting left ventricular hypertrophy. Echocardiography must be performed, with the results corrected for age and surface area, in order to detect and follow these abnormalities.     

Right heart pressure determination by Doppler in infants with tricuspid regurgitation

Doppler and direct measurements of right ventricle to right atrial pressure drop were made during cardiac catheterisation on 28 occasions in 26 infants with congenital heart disease. Age was 10 days to 12 months (median 4.5 months), and weight was 3.1 to 9.0 kg (median 4.7 kg). We measured peak velocity of tricuspid regurgitation by continuous wave Doppler, and the pressure drop was calculated using the modified Bernoulli equation (delta p = 4v2). There was a high correlation (r = 0.95) between direct and Doppler measurements. Doppler values tended to underestimate the right ventricle to right atrial pressure drop, but this was not of clinical significance (mean 2 mm Hg). The 95% confidence interval for the Doppler velocity was -0.41 to +0.26 m/sec, and was consistent across the range of pressures studied. Variability between observers was tested, by two observers performing sequential paired examinations on 16 newborn babies with tricuspid regurgitation. The coefficient of repeatability was 6.3 mm Hg (95% confidence interval 4.7 to 9.5 mm Hg) or 0.26 m/sec (0.18 to 0.50 m/sec). This method of right ventricular pressure estimation, validated previously only in older children and adults, is a reproducible and accurate technique in infants with tricuspid regurgitation.     

Beyond the Coronary Angiogram: Further Evaluation of the Coronary Vasculature and Endothelial Function

Coronary artery disease is a progressive and diffuse process. The focus in the past decade was on the late stage of coronary atherosclerosis, with efforts being devoted to the development of thrombolytic drugs and sophisticated interventional devices. However, in spite of the success in decreasing morbidity and mortality from coronary atherosclerosis, the disease process continues. Early diagnosis and treatment of patients with nonobstructive coronary artery disease, may prevent the development of unstable angina and myocardial infarction. It has become apparent that the endothelium is the primary target and/or participant in the early stages of coronary atherosclerosis. The endothelium is as an active paracrine organ capable of regulating coronary vascular tone as well as the atherosclerotic and restenosis process by releasing vasorelaxing factors with antiproliferative activity and vasoconstricting and growth factors. During the evolution of coronary atherosclerosis endothelial dysfunction occurs, which is characterized by attenuated release and activity of endothelium derived vasorelaxing factors and enhanced release of vasoconstricting factors. The goal of cardiology is to develop diagnostic methods and treatment for these patients who present to us with cardiac symptoms and nonobstructive coronary artery disease. This article will review the current knowledge of endothelial function as it applies to coronary circulation and describe a clinical approach to the patient with suspected coronary disease and a normal coronary angiogram. (J Interven Cardiol 1996;9:153–161)     

Nasal mask positive pressure ventilation in paediatric patients with type II respiratory failure

We report our experience with nasal mask ventilation in children and adolescents with type II respiratory failure admitted to the paediatric intensive care unit (PICU) over an 18-month period. Seven patients were treated with nasal mask ventilation during part of their PICU stay. All showed significant improvement in arterial pH, Pa_CO2, and Pa_O2/FiO₂ from presentation to discharge, although at discharge Pa_CO2 and Pa_O2/FiO₂ fell outside of the normal range. Complications occurred in four patients. When compared to 11 patients with type II respiratory failure not treated with nasal mask ventilation, the nasal mask ventilation group had a similar PICU length of stay and incidence of complications. We conclude that nasal mask ventilation may be useful in maintaining near normal alveolar ventilation in selected children with type II respiratory failure and that a prospective study of this technique is indicated.     

The effect of coronary artery bypass surgery on ventricular arrhythmias

The effect of coronary artery bypass surgery (CAB) on ventriculararrhythmias (VA) was studied in a prospective investigationinvolving 32 patients (mean age 54 years) who underwent CABbecause of severe stable angina pectoris. Prior to CAB as wellas 12 months later each patient was subjected to the followinginvestigational programme: resting ECG, exercise ECG, 24-h ECG,selective coronary arteriography, ventriculography and cardiaccatheterization. Exercise ECG showed VA in only three patients.The prevalence of VA during 24-h ECG was 56 and 66% on the twooccasions (NS), while complicated VA (multiform, repetitive,R on T) was seen in 18 and 28%, respectively (NS). The persistence(number of 6-h periods showing VA) was 33 and 47% with regardto any VA (P<0.05), while complicated VA occurred in 13 and15% of the 6-h periods (NS). Except for an increase in dp/dt_max/Pat the postoperative measurement (P<0.05), no significantchange in the performance of the left ventricle was seen afterCAB though the graft patency was 77%. It is concluded that inpatients with ‘medically intractable’ stable anginapectoris, CAB does not effect the occurrence of VA to any greatextent — probably because left ventricular function isunchanged one year after as compared with that prior to CAB.     

THE RESPIRATORY EFFECTS OF A POTENT ANALGESIC (GPA 2087) IN MAN

The respiratory depressant effects of a potent analgesic (GPA2087) were compared with morphine in a randomized double-blindcross-over study in human volunteers. Using a rebreathing technique,carbon dioxide response curves were plotted automatically witha special-purpose analog computer. The respiratory depressantrelative potency of GPA 2087 to morphine was found to be 1.21with lower and upper 95 per cent confidence limits of 0.88 and2.04. Our best estimate based on the displacement of the respiratoryresponse curve is that GPA 2087 8 mg is the equivalent of morphine10 mg in our population of volunteers. ^*Geigy Pharmaceuticals, Ardsley, New York, U.S.A. ^*Present address: Salisbury General Infirmary, Odstock Branch,Salisbury, Wiltshire, England.