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Biomedical subjects

P Howat

Publications and source records attributed to P Howat.

33 records · Page 2Linked to original sources
PubMed1979

Clinical events relating to intraventricular haemorrhage in the newborn.

Continuous measurements of arterial pressures, heart rates, respiratory movements, and respiratory rates were made from birth in 44 infants at risk from intraventricular haemorrhage (IVH). 17 babies died with IVH, in 10 of whom the event was timed objectively. Events in these babies were compared with survivors of similar birthweights, gestational ages, severity of birth asphyxia, and severity of hyaline membrane disease (HMD). IVH followed severe HMD and was associated with cessation of the babies' own respiratory efforts while on a ventilator and also with characteristic cardiorespiratory events. The minimum arterial pressure before IVH was lower than in comparable babies who survived. It is suggested that fluctuations of systemic blood pressure from initial low levels may be important in the pathogenesis of IVH. It is possible that changes in cerebral blood flow are of even greater significance.

Asphyxia Neonatorum↗
PubMed1977

Obstetric practice and infant morbidity.

A method is described of using matched pairs of index infants and controls to examine the hypothesis that induction or some other obstetric practice is associated with increased morbidity in the mature infant. All infants over 2250 g and 37 weeks gestation, without severe congenital defect or history of severe maternal disorder, born in the John Radcliffe and admitted to the Special Care Baby Unit in 1975 were identified. For each of these index infants a matched control was chosen using strict criteria. Contrast between the 109 matched pairs showed no significant differences between maternal characteristics, induction of labour, use of forceps or duration of labour. There was an excess of index infants born to mothers who had had epidural anaesthesia (P less than 0.05).

Extraction, Obstetrical↗
PubMed1977

Timing of intraventricular haemorrhage.

The detection of the onset of intraventricular haemorrhage (IVH) during life is a necessary preliminary to understanding the cause of this condition. In 10 infants of very low birthweight treated with serial transfusions of adult blood the proportions of transfused cells circulating after each transfusion were compared with the proportion of transfused cells found in the intraventricular clot at necropsy. This allowed the timing of IVH to be restricted retrospectively to the period between consecutive blood transfusions. In addition, the proportional changes of transfused cells produced by infusion of a known red cell mass allow changes in the babies' original red cell mass to be followed during life. A fall in this value occurred in 8 infants dying with IVH and was taken to indicate haemorrhage. Comparison of the two methods in 9 infants suggested that, while in some cases intraventricular bleeding occurs rapidly, in others it takes place over a period of time. The interval between birth and the onset of haemorrhage was directly proportional to the gestational age of the infant.

Blood Transfusion↗
PubMed1977

Effect of blood transfusion in low birthweight infants.

143 fresh blood transfusions were given to 32 low birthweight babies, 28 of whom had hyaline membrane disease. The arterial or central venous pressure was raised by a blood transfusion if before transfusion the mean arterial pressure was less than 35 mmHg or if the diastolic central venous pressure was less than -- 0-5 mmHg. There was no effect of blood transfusion on pH. It therefore appears either that metabolic acidosis in hyaline membrane disease is not caused by poor peripheral perfusion or that blood transfusion does not increase peripheral blood flow in this condition. The safety of the procedure is assessed.

Blood↗
PubMed1976

Contribution of preterm delivery to perinatal mortality.

A detailed retrospective analysis was made of the records of 486 preterm infants, who accounted for 5-1% of all births during 1973 and 1974. Whereas preterm delivery did not contribute to perinatal mortality in terms of stillbirth, it outweighed all other causes in terms of early neonatal deaths. Preterm birth was responsible for 85% of the early neonatal deaths not due to lethal congenital deformities. Early neonatal mortality rates were closely linked both to gestational age and birth weight and to the reason for preterm birth. Early neonatal mortality was high (97 per 1000) when preterm labour was spontaneous, whether or not associated with material or fetal disease or with multiple pregnancy, but low (27 per 1000) when preterm delivery was elective. Preventing spontaneous preterm labour would considerably reduce neonatal mortality in our community.

England↗
PubMed1975

Hypernatraemia as a cause of intracranial haemorrhage.

29 definite intracranial haemorrhages and 4 suspected ones occurred during a 25-month period during which 10 072 live infants were born. There were 4 subdural haemorrhages (all fatal), 4 isolated subarachnoid haemorrhages (2 fatal), and 21 intraventricular haemorrhages (all fatal--2 beyond the neonatal period). There was no evidence of a causal relation between intraventricular haemorrhage and either hypernatraemia or large sodium intakes. There were too few cases of other types of intracranial haemorrhage to draw any aetiological conclusions.

Birth Weight↗