Point care testing in blood gas and electrolyte analysis : examples of implementation and cost analysis

An increasing proportion of laboratories manage and organize point of care testing (POCT). The purpose of this article is to describe the implementation made at Lariboisière hospital for three remote blood gas analysers. The most important aspect in this achievement is the comprehensive computerization, making possible real time management of POCT in agreement with the Point of Care unit Management team. In addition, we present a running cost analysis, comparing three Blood gas systems (Rapidlab860, Rapidpoint 400--Bayer Diagnostics and i-Stat Abbott Diagnostics). This study indicates that cost per test hugely varies based on the daily sample demand. In addition to analytical and organizational items, the clinical chemist should consider the testing demand as a key factor in choosing an analyser for POCT.     

Cost analysis. Bedside blood glucose testing.

Cost analysis of the bedside blood glucose testing program at a Veterans Affairs medical center indicated a per-test cost of $11.50, as opposed to the conventional laboratory testing cost for serum glucose of $3.19. Extrapolated to the 172 Veterans Affairs hospitals, the extra cost of the procedure is estimated to be in excess of $3 million each year.     

Air bubbles and temperature effect on blood gas analysis.

The effect of temperature, time of storage, and presence of air bubbles in specimens for blood gas analysis was studied. The results show that air bubbles in a 10% proportion are undesirable because of significant elevation in the PO2, and the storage of anaerobic blood samples at room temperature (25 degrees C) is acceptable when measurements are done within the first 20 minutes.     

The rise and fall of i-STAT point-of-care blood gas testing in an acute care hospital

In response to a $350,000 laboratory budget cut and closure of an intensive care unit-based laboratory and a desire to maintain turnaround times of 10 minutes or less, a multidisciplinary group developed and implemented point-of-care (POC) testing. Only blood gases (pH, PO2, and PCO2) and ionized calcium values were deemed essential stat tests. Three commercially available POC blood gas devices were evaluated; all yielded results comparable to in-house reference methods. The 1 device with a US Food and Drug Administration-approved method for ionized calcium testing and with an existing interface for laboratory information systems was selected. Fiscal analysis predicted annual savings of approximately $225,000. POC blood gas analysis was implemented in April 1996 coincident with closure of the intensive care unit-based laboratory. Clinical laboratories and POC blood gas test volumes remained constant through August 1998; in contrast, the number of ionized calcium tests decreased dramatically after April 1996. In August 1998, clinically significant (i.e., artificial ventilation parameters would have been altered based on test results) discrepant PCO2 values were observed sporadically and noted only with patient specimens, not with commercial controls or electronic simulators. Because investigation failed to identify the cause, use of the POC device was discontinued in September 1998.     

Reasons for proficiency testing failures in clinical chemistry and blood gas analysis: a College of American Pathologists Q-Probes study in 665 laboratories

OBJECTIVE: To determine the reasons for proficiency testing (PT) failures from 41 chemistry and blood gas analytes using data collected to benchmark performance. DESIGN: Self-administered survey requesting number of challenges by analyte encompassing nine PT events. When the challenge resulted in a self-defined failure, further information was requested concerning the magnitude of the failure (as a standard deviation index) and categorization of the type of failure into six major groups (Methodologic, Technical, Clerical, Survey, Unexplained, or Other) and then into subgroups. PARTICIPANTS: Laboratories enrolled in the 1992 College of American Pathologists Q-Probes program. MAIN OUTCOME MEASURES: Rate of PT failures and reasons for failure. RESULTS: Proficiency testing data from 670,489 challenges performed in 665 laboratories revealed 9268 (1.4%) unacceptable results. Failure types were distributed as follows: Methodologic, 33.5%; Technical, 17.4%; Clerical, 11.1%; Survey, 7.8%; Unexplained, 25.7%; and Other, 7.4%. CONCLUSIONS: Individual analyte PT failure is a common event in the participating laboratories, but failures in successive or alternate events are rare. Analysis of the reasons for failed events indicates that most identified reasons occurred in either the Methodologic or Technical categories (50.9%). Analysis of the failure types suggested investigation pathways based on the magnitude of the failure that could reduce the 25.7% rate of unexplained failures.     

Smoking induced changes in EEG two-dimensional maps and blood gas analysis

Summary The effects of smoking on mental function were investigated by the two-dimensional EEG mapping method, and the results were analyzed in conjunction with blood gas data that had been obtained simultaneously. Healthy medical students from the National Defense Medical College were used as the subjects for this experiment. They live in the same dormitory and a similar lifestyle to regular military personnel. Tests were carried out on two successive days, and in between the two testing sessions, each subject was requested to refrain from smoking for 24 hours. During the testing sessions, EEGs were recorded with eyes closed, before and after smoking. Two-dimensional maps were generated by unbiased polynomial interpolation for alpha activity. Various blood chemical measurements were made, among which, partial pressure of carbon dioxide (pCO₂) and percentage of carbon monoxide hemoglobin (%COHb) were studied in relation to EEG changes. The smoking induced wide-spread amplitude decrease in the alpha maps. After 24 hours of withdrawal, alpha amplitude increased, although it decreased again when smoking resumed. Either the correlation between EEG amplitude and %COHb, or the correlation between EEG amplitude and pCO₂, was examined in three regions (anterior: A, middle: M and posterior: P) of the two-dimensional maps in both slow and quick smokers. There were no correlations observed between changes in the EEG amplitude and changes in %COHb induced by smoking, in any of the three regions in either fast or slow smokers. However, there was a clear correlation between changes in the EEG amplitude and changes in pCO₂ in quick smokers, the correlation coefficient being approximately -0.7. It is possible that this relationship was due to hyperventilation, since the same tendency was not observed in slow smokers.This work was supported by a grant from the Smoking Research Center.