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Biomedical subjects

I E Hopkin

Publications and source records attributed to I E Hopkin.

41 records · Page 3Linked to original sources
PubMed1977

Effects of continuous distending pressure on lung volumes and lung mechanics in the immediate neonatal period.

The effects of CPAP and CNEP on lung mechanics and lung volumes were investigated in a group of 12 healthy newborn infants. Both resulted in a mild suppression of respiration. The fall in TPR50 was far greater during CPAP than during CNEP. Both led to a one third fall in dynamic compliance. Approximately 50% of the distending pressure was transmitted to the mediastinal structures whether applied as CPAP or CNEP.

Airway Resistance↗
PubMedDate not supplied

Calculation of mean airway pressure during neonatal intermittent positive pressure ventilation and high frequency positive pressure ventilation.

Because mean airway pressure (MAP) is extensively used to quantify ventilation administered during the neonatal period, the accuracy and reproducibility of the techniques currently used to define MAP were assessed. All techniques were found to compare closely with MAP measured by integration of the pressure wave form even at ventilator rates in excess of 100 breaths per minute. It was therefore concluded that all methods currently used are satisfactory for clinical use.

Humans↗
PubMedDate not supplied

Determinants of the first inspiratory volume and functional residual capacity at birth.

We have investigated the pattern of pressure and volume changes that occur in vaginally delivered, full-term infants during the onset of spontaneous respiration. Within a few seconds of delivery of the head, simultaneous measurements were made of stomach and esophageal pressure changes together with volume changes determined at the mouth. Values obtained for volume were very similar, but pressure changes were of a greater magnitude than previously reported. A significant correlation has been shown between first inspiratory volume and functional residual capacity (FRC) at the end of the first breath (p less than 0.004). No significant relationship was found between first inspiratory pressure and FRC. However, using a calculated index of inspiratory pressure and time ("inspiratory effort"), a significant relationship of this to FRC was observed (p less than 0.02).

Delivery, Obstetric↗
PubMedDate not supplied

Changing patterns in neonatal respiratory diseases.

Using the current Nottingham Health District, England, as a geographically defined population we have investigated the changing patterns of neonatal respiratory diseases. We have categorized all newborns who developed a respiratory problem during either 1977 or between April 1, 1983, and March 31, 1984 using a system based on that of Hjalmarson (Acta Paediatr Scand 1981; 70:773-783). There has been no change in the incidence of any of the disease types. However, the gestation of babies in two groups, idiopathic respiratory distress syndrome (IRDS) and minimal respiratory disturbance (requiring added oxygen for less than 6 hours), has shown a significant reduction. Overall, mortality for infants developing IRDS has shown a slight decrease, and for infants between 29 and 32 weeks gestation, mortality has shown a significant reduction. Overall, requirements for oxygen therapy and ventilation have shown a threefold increase, while hours in receipt of continuous positive airways pressure (CPAP) have increased sevenfold.

England↗