Neonatal cerebral Doppler: arterial and venous flow velocity measurements using color and pulsed Doppler system.

OBJECTIVE: To contribute to the establishment of reference values of blood flow velocity assessed by cerebral Doppler in healthy infants related to gestational age and birth weight during the first week of life. METHODS: Five arteries and three veins were evaluated respectively in 120 (74 premature) newborns and in 100 (70 preterm) infants. In a quarter of the latter three recordings at 5-minute intervals were made to assess reproducibility. The relation between flow measurements and gestational age was assessed by linear regression, means by analysis of variance (or Kruskall-Wallis test) and paired samples by Student's t test. RESULTS: There was a significant increase of arterial velocities with increasing gestational age and birth weight, but not for venous velocities. Significant higher values were found in the internal carotid artery followed by the medium cerebral artery. The venous velocities were highly reproducible and the main patterns observed were bandlike and sinusoid type. CONCLUSION: The knowledge of normal cerebrovascular physiology is essential to understand the pathogenesis of neonatal brain damage and can help pediatricians in an accurate interpretation of the flow profile in neurological pathology.

Does umbilical vein catheterization to exchange transfusion lead to portal vein thrombosis?

UNLABELLED: The aetiopathology of extrahepatic portal vein obstruction is unknown. In retrospective studies, umbilical vein cannulation and sepsis have been alleged to cause portal thrombosis. This prospective study was undertaken to detect whether thrombosis and consequent obstruction of the splenoportal venous system develops after umbilical vein catheterization for exchange transfusion in newborns using Doppler ultrasound. Forty children (M = 24; F = 16) who had undergone exchange transfusion for hyperbilirubinaemia were studied at school age. Maximal duration of the venous umbilical cannulation was 120 min and sepsis did not occur. Clinical, biological and sonographic examinations were normal, except in 3 children. In 2 the left branch of portal vein could not be identified (normal variant). CONCLUSION: Our results show that, in these children, umbilical vein catheterization did not lead to development of portal vein thrombosis. However, when other risk factors such as umbilical infection, traumatic catheterization are associated, children should be screened for obstruction of the portal vein.

[The noise in neonatal intensive care units]. / Le bruit dans une unité de soins intensifs néonatals.

BACKGROUND: Noise constitutes a significant problem in Neonatal Intensive Care Units (NICU) because of its potential deleterious effects on the newborn patients and staff. The aim of this study was to evaluate the degree of noise in the NICU of Hospital S João, Oporto, in order to identify its origin and possibility of reducing it. MATERIAL AND METHODS: Measurements of noise were made for 24 hours, between 13 and 14 June 1994, in five different locations inside the NICU, using a slow time constant sonometer. RESULTS: The surrounding noise level changed between 61 and 67 dB (A), with spikes over 100 dB (A). CONCLUSIONS: Our results were similar to those previously reported in the literature. The following measures to reduce the level of noise were taken: 1) reduction of alarm sounds to minimal safe level; 2) replacement of doors; 3) instructions to visitors and staff.

[Sepsis in the very low-birth-weight newborn infant]. / Sépsis no recém-nascido de muito baixo peso.

Sepsis is a common pathology during the neonatal period. Low-birth weight is the most important isolated risk factor. With the purpose of determining the prevalence of nosocomial infection in newborns of very low birth weight (VLBW), finding the microbial flora and the mortality of these patients, the authors retrospectively analysed the clinical processes of the hospitalized VLBW in the Neonatal Intensive Care Unit (NICU) in S. João Hospital in 1993 and 1994. Of the 1091 newborns admitted to the hospital in these two years, 112 were VLBW (10%). Of these, 48 had sepsis-31 (28%) confirmed sepsis and 17 (15%) probable sepsis. The agents most commonly found were Staphylococcus epidermidis (44%) and Klebsiella pneumoniae (21%). Thirteen patients (27%) died, with infection as the cause of death in nine (19%). Our results confirm the importance of nosocomial neonatal infection, which should involve the strict observance of the asepsis norms and a proper policy of antibiotics.