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Biomedical subjects

I A Sloan

Publications and source records attributed to I A Sloan.

11 recordsLinked to original sources
PubMed1991

Effects of age and cardiac shunts on the measured uptake of nitrous oxide in children.

The uptake of nitrous oxide (N2O) was calculated by using a new application of pharmacokinetics involving cumulative fractional expired N2O concentration at 90 percent steady state. The effect of age on N2O uptake was investigated in 33 normal children undergoing non-cardiac surgery. Uptake was also investigated in 17 children with right-to-left cardiac stunts and 18 children with left-to-right shunts undergoing corrective or palliative cardiac surgery. There was a significant correlation of N2O elimination half-life (T1/2) with age for normal children (p less than 0.001), and for children with right-to-left (p less than 0.001) or left-to-right (p = 0.05) shunts. Elimination T1/2 in children with left-to-right shunts correlated significantly with the calculated shunt fraction (p less than 0.05). By providing a useful means for comparison, this method of measuring N2O uptake permits determination of the effects of age, weight and cardiac shunts on the uptake kinetics of N2O.

Age Factors↗
PubMed1985

Evaluation of the jet injector in paediatric fibreoptic bronchoscopes.

The use of the Sanders venturi system during bronchoscopy in adults has been studied extensively. Its use in paediatric bronchoscopy has been limited because small changes in the characteristics of the system may produce large changes in the patient. With jet ventilation, peak inflation pressures and flow rates are influenced by the driving pressure, diameter and shape of the bronchoscope, the diameter of the injector and its length and angle from the axial line of the bronchoscope. Storz 3 mm, 4 mm and 5 mm rigid fibreoptic bronchoscopes were evaluated in a test lung with an injector of 1.5 mm internal diameter fixed in the side-arm at 20 degrees to the axial line. Pilling 3 mm, 4 mm and 5 mm rigid fibreoptic bronchoscopes were also examined using the standard injector with a 0.89 mm orifice in the axial line. The Storz bronchoscopes produced consistently higher peak inflation pressures and flow rates at all driving pressures in spite of the relatively large angle of the injector from the axial line. Caution is advised in the use of the Storz injector system as excessively high inflation pressures may be reached.

Anesthesia, General↗
PubMed1984

Internal mis-mating of breathing system components.

A patient anaesthetized for bronchoscopy could not be ventilated when components of the breathing system met too closely and prevented the out flow of expired gas. This type of obstruction within the system may occur in the Ayre's T-piece, and when "low dead space" mask angles or co-axial systems are used with "low dead space" tracheal connectors or bronchoscopes. The problem is especially dangerous because it is not easily identified and subjects the patient to a very high airway pressure.

Aged↗