Oximeter reliability in a subzero environment.

A J Macnab; M Smith; N Phillips; P Smart

Home/Archive/PubMed

PubMed · 8908343

Oximeter reliability in a subzero environment.

A J Macnab·M Smith·N Phillips·P Smart

View original source ↗Export metadata ↓

Abstract

BACKGROUND: Pulse oximeters optimize care in the pre-hospital setting. As British Columbia ambulance teams often provide care in subzero temperatures, we conducted a study to determine the reliability of 3 commercially-available portable oximeters in a subzero environment. NULL HYPOTHESIS: We hypothesized that there is no significant difference between SaO2 readings obtained using a pulse oximeter at room temperature and a pulse oximeter operating at sub-zero temperatures. METHODS: Subjects were stable normothermic children in intensive care on Hewlett Packard monitors (control unit) at room temperature. The test units were packed in dry ice in an insulated bin (temperature - 15 degrees C to -30 degrees C) and their sensors placed on the subjects, contralateral to the control sensors. Data were collected simultaneously from test and control units immediately following validation of control unit values by co-oximetry (blood gas). RESULTS: No data were unacceptable. Two units (Propaq 106EC and Nonin 8500N) functioned well to < -15 degrees C, providing data comparable to those obtained from the control unit (p < 0.001). The Siemens Micro O2 did not function at the temperatures tested. CONCLUSIONS: Monitor users who require equipment to function in subzero environments (military, Coast Guard, Mountain Rescue) should ensure that function is reliable, and could test units using this method.

Explore related subjects

Analysis of Variance Child Child, Preschool Cold Temperature Confidence Intervals Critical Care Electrocardiography Equipment Failure Evaluation Studies as Topic Freezing Humans Infant Linear Models Oximetry Reproducibility of Results Journal Article Research Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

A J Macnab, M Smith, N Phillips, P Smart. 1996. Oximeter reliability in a subzero environment.. https://pubmed.ncbi.nlm.nih.gov/8908343/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2025

Chemical defibrillation in acute myocardial ischaemia: a hypothesis.

Explore the source record for details and available documents.

Analysis of Variance↗

PubMed2014

Molecular heterochrony and the evolution of sociality in bumblebees (Bombus terrestris).

Sibling care is a hallmark of social insects, but its evolution remains challenging to explain at the molecular level. The hypothesis that sibling care evolved from ancestral maternal care in primitively eusocial insects has been elaborated to involve heterochronic changes in gene expression. This elaboration leads to the prediction that workers in these species will show patterns of gene expression more similar to foundress queens, who express maternal care behaviour, than to established queens engaged solely in reproductive behaviour. We tested this idea in bumblebees (Bombus terrestris) using a microarray platform with approximately 4500 genes. Unlike the wasp Polistes metricus, in which support for the above prediction has been obtained, we found that patterns of brain gene expression in foundress and queen bumblebees were more similar to each other than to workers. Comparisons of differentially expressed genes derived from this study and gene lists from microarray studies in Polistes and the honeybee Apis mellifera yielded a shared set of genes involved in the regulation of related social behaviours across independent eusocial lineages. Together, these results suggest that multiple independent evolutions of eusociality in the insects might have involved different evolutionary routes, but nevertheless involved some similarities at the molecular level.

Analysis of Variance↗

PubMed2005

Population structure and properties of Candida albicans, as determined by multilocus sequence typing.

We submitted a panel of 416 isolates of Candida albicans from separate sources to multilocus sequence typing (MLST). The data generated determined a population structure in which four major clades of closely related isolates were delineated, together with eight minor clades comprising five or more isolates. By Fisher's exact test, a statistically significant association was found between particular clades and the anatomical source, geographical source, ABC genotype, decade of isolation, and homozygosity versus heterozygosity at the mating type-like locus (MTL) of the isolates in the clade. However, these associations may have been influenced by confounding variables, since in a univariate analysis of variance, only the clade associations with ABC type and anatomical source emerged as statistically significant, providing the first indication of possible differences between C. albicans strain type clades and their propensity to infect or colonize different anatomical locations. There were no significant differences between clades with respect to distributions of isolates resistant to fluconazole, itraconazole, or flucytosine. However, the majority of flucytosine-resistant isolates belonged to clade 1, and these isolates, but not flucytosine-resistant isolates in other clades, bore a unique mutation in the FUR1 gene that probably accounts for their resistance. A significantly higher proportion of isolates resistant to fluconazole, itraconazole, and flucytosine were homozygous at the MTL, suggesting that antifungal pressure may trigger a common mechanism that leads both to resistance and to MTL homozygosity. The utility of MLST for determining clade assignments of clinical isolates will form the basis for strain selection for future research into C. albicans virulence.

Analysis of Variance↗