Biomedical subjects

K M McRae

Publications and source records attributed to K M McRae.

3 recordsLinked to original sources

PubMed1991

Simple developmental speech delay: a follow-up study.

The authors followed 38 children with delayed speech development approximately two to four years after initial diagnosis, assessing and comparing their subsequent speech and language, and over-all development. Nearly all of the children had appropriate language levels for their general development. Just over half had less articulation competence than expected for their age, but this was not related to language achievement or age. It appears that the prognosis for future language development is favourable for these children. The results suggest that articulation might be a developmentally related process with a good prognosis, but further follow-up is necessary to determine ultimate competence of children in whom this is delayed.

Articulation Disorders↗

PubMed1989

A randomized comparison of total extracorporeal CO2 removal with conventional mechanical ventilation in experimental hyaline membrane disease.

Apnoeic oxygenation (AO) combined with extracorporeal CO2 removal (ECCO2R), using venovenous perfusion across a membrane area of 0.1 m2 has been shown to be feasible in six healthy anaesthetized rabbits. In a further twelve rabbits, ECCO2R has been randomly compared with conventional mechanical ventilation (CMV) following saline lavage to induce respiratory failure. Blood gases were maintained for up to 6 h within the same range (PaO2 = 8-20 kPa, PaCO2 = 4-6 kPa) in two groups of six by varying airway pressures and the oxygen fraction delivered either to the membrane lung (ECCO2R group) or to the ventilator (CMV group). The influence of single hourly sustained inflations (SI) on oxygenation was studied. ECCO2R subjects remained stable and survived. CMV subjects deteriorated and had 80% mortality. Hyaline membranes were absent from ECCO2R subjects and present in all CMV subjects. The response to SI suggests that a lung volume recruitment is maintained during AO for up to 1 h but is ineffective during CMV.

Animals↗

PubMed1989

Haemolysis during in vitro CO2 removal from human blood using a membrane lung.

Haemolysis of human blood has been examined in vitro as a function of pH in the range 7.2-8.0. The hydrogen ion concentration of freshly donated blood from 11 donors was manipulated in 42 experiments, entirely by altering the carbon dioxide fraction of air with which the blood was equilibrated using a membrane lung. In contrast to the known alkalaemic haemolysis which occurs in canine blood, we observed no correlation between plasma haemoglobin concentrations and blood pH. We conclude that alkalaemic haemolysis is unlikely to complicate the clinical application of extracorporeal carbon dioxide removal in the management of acute respiratory failure.

Acid-Base Equilibrium↗