RESUMO
We describe a scavenging device, primarily for use during inhalation induction of anaesthesia in children; it was designed to optimize the often conflicting requirements of clinical acceptability and adequate gas collection. The performance was assessed in three ways. The device reduced the nitrous oxide concentration in the breathing zone of the anaesthetist during inhalation induction to about 100 p.p.m. We also describe a method to measure the direct catchment of nitrous oxide expressed as a percentage of the total nitrous oxide used. In 46 patients the mean percentage collection was 82%. Using personal sampling devices, we found that comprehensive scavenging in paediatric anaesthesia can reduce the average exposure of anaesthetists to about 130 p.p.m. of nitrous oxide.
Assuntos
Anestesia por Inalação/instrumentação , Depuradores de Gases/normas , Poluentes Ocupacionais do Ar/análise , Criança , Pré-Escolar , Desenho de Equipamento , Estudos de Avaliação como Assunto , Humanos , Lactente , Óxido Nitroso/análiseRESUMO
The Ruben circle anaesthesia system was studied in the spontaneous breathing mode, and under certain conditions there was incompetence of the replaceable mushroom control valve. This causes a reverse flow of gas which results in rebreathing of expired gas when the system is used on spontaneously breathing patients. A patient simulator was used to investigate the way in which the reverse flow of gas depends on ventilatory parameters and fresh gas flow. The inspired concentration of carbon dioxide increased for increased fresh gas flow and for decreased tidal volume. These results were confirmed by observations on anaesthetised adult and paediatric patients during spontaneous breathing. We conclude that the system in its present form, is not suitable for use on spontaneously breathing paediatric patients.
Assuntos
Anestesia por Inalação/instrumentação , Respiração , Adulto , Dióxido de Carbono/análise , Criança , Estudos de Avaliação como Assunto , Humanos , Reologia , Volume de Ventilação PulmonarRESUMO
The use of perchlorate to block gastric uptake of free 99Tcm-pertechnetate after in vivo labelling of red cells was investigated. In 19 out of 20 cases there was no evidence that previous administration of perchlorate adversely affected red cell labelling using commercial stannous agents. Adequate scintigraphic images of the vascular system could be obtained for up to 24 h after the cells were labelled. The technique was found to be of value in the investigation of sites of gastrointestinal bleeding.
Assuntos
Hemorragia Gastrointestinal/diagnóstico por imagem , Percloratos , Compostos de Sódio , Colo/diagnóstico por imagem , Doenças do Colo/diagnóstico por imagem , Eritrócitos , Varizes Esofágicas e Gástricas/diagnóstico por imagem , Feminino , Humanos , Masculino , Cintilografia , Pertecnetato Tc 99m de Sódio , Estômago/diagnóstico por imagemRESUMO
A new technique has been introduced whereby test signals are injected acoustically into a diagnostic scanner under test--no direct electrical connection is therefore needed. A simple battery operated instrument has been produced which will operate with all types of imaging equipment and which is particularly suitable for the routine checking of velocity and caliper calibrations, the assessment of scale factors, measurement of dynamic range and the effect of signal processing options on grey-scale dynamic range and the effect of signal processing options on grey-scale behaviour and for the adjustment of display and hard copy units.
