Comparison of Point-of-Care and Laboratory Glucose Values in Cardiothoracic Surgery Patients

2.50
Hdl Handle:
http://hdl.handle.net/10755/156971
Category:
Abstract
Type:
Presentation
Title:
Comparison of Point-of-Care and Laboratory Glucose Values in Cardiothoracic Surgery Patients
Author(s):
Denfeld, Quin E.; Stafford, Kelly
Author Details:
Quin E. Denfeld, RN,BSN,CCRN, OHSU, Portland, Oregon, USA, email: denfeldq@ohsu.edu; Kelly Stafford
Abstract:
POSTER PURPOSE: This descriptive quality improvement study aimed to determine the difference between blood glucose values from point-of-care (POC) glucometers and laboratory blood glucose values in cardiothoracic surgery patients, particularly in comparison with hematocrit values. BACKGROUND/SIGNIFICANCE:Protocols for tight glycemic control (80-110 g/dL) have become standard practice in many intensive care units (ICUs). Subsequent results on this practice have been variable, and recently some have demonstrated that POC glucometers have variable accuracy, particularly if hematocrit values are less than 25%. At our institution, adult ICU insulin infusion protocols may result in hypoglycemia as we base our therapy on POC glucometer results that may be significantly different from laboratory values. METHOD: Our sample included cardiac surgery patients on postoperative day 0. Study participants had to have an arterial catheter in place and have ordered morning laboratory tests, including a renal function set and a complete blood cell count. A single sample of arterial blood was collected and analyzed both by the nurse at the bedside with the Precision XCeedPro glucometer to obtain a POC glucose value and in the OHSU hospitalÆs laboratory with the Beckman Coulter DXC 800 and LH 780 machines. The POC glucose value, the laboratory glucose value, and the hematocrit data were recorded along with demographic data. Data analysis included descriptive statistics, a paired t test to compare the mean differences, and Spearman correlation. RESULTS: In our preliminary analysis, data were collected from 41 adults; mean age was 61.2 years (SD 13.2), 39 (95%), were white, 27 (66%) were male, and 28 (68%) had undergone coronary artery bypass grafting. Mean hematocrit was 27.4 (SD 4.9), mean POC glucose was 110.3 mg/dL (SD, 29), and mean laboratory glucose was 97.2 mg/dL (SD, 25.1). The mean difference between POC and laboratory glucose was 13.2 mg/dL (SD, 9.8), with POC glucose the higher value. Difference scores ranged from 33 mg/dL to - 7 mg/dL. A paired t test revealed t = 8.6, P < .001. Nonparametric correlation was used because hematocrit was not normally distributed; the Spearman rho correlation between the difference scores and hematocrit was - 0.36, P = .02. CONCLUSIONS: These findings demonstrate that substantial differences may occur with POC and laboratory testing of blood glucose on identical samples, raising concerns about the safety and appropriateness of tight glycemic control in postoperative cardiothoracic surgery patients. The difference between POC and laboratory measurements of glucose was inversely related to hematocrit, suggesting that patients with postoperative anemia are at greater risk for hypoglycemia.
Repository Posting Date:
26-Oct-2011
Date of Publication:
26-Oct-2011
Citation:
2010 National Teaching Institute Research Abstracts. American Journal of Critical Care, 19(3), e15-e28. doi:10.4037/ajcc2010866
Conference Date:
2010
Conference Name:
National Teaching Institute and Critical Care Exposition
Conference Host:
American Association of Critical-Care Nurses
Conference Location:
Washington, D.C., USA
Note:
This is an abstract-only submission. If the author has submitted a full-text item based on this abstract, you may find it by browsing the Virginia Henderson Global Nursing e-Repository by author. If author contact information is available in this abstract, please feel free to contact him or her with your queries regarding this submission. Alternatively, please contact the conference host, journal, or publisher (according to the circumstance) for further details regarding this item. If a citation is listed in this record, the item has been published and is available via open-access avenues or a journal/database subscription. Contact your library for assistance in obtaining the as-published article.

Full metadata record

DC FieldValue Language
dc.type.categoryAbstracten_GB
dc.typePresentationen_GB
dc.titleComparison of Point-of-Care and Laboratory Glucose Values in Cardiothoracic Surgery Patientsen_GB
dc.contributor.authorDenfeld, Quin E.en_GB
dc.contributor.authorStafford, Kellyen_GB
dc.author.detailsQuin E. Denfeld, RN,BSN,CCRN, OHSU, Portland, Oregon, USA, email: denfeldq@ohsu.edu; Kelly Stafforden_GB
dc.identifier.urihttp://hdl.handle.net/10755/156971-
dc.description.abstractPOSTER PURPOSE: This descriptive quality improvement study aimed to determine the difference between blood glucose values from point-of-care (POC) glucometers and laboratory blood glucose values in cardiothoracic surgery patients, particularly in comparison with hematocrit values. BACKGROUND/SIGNIFICANCE:Protocols for tight glycemic control (80-110 g/dL) have become standard practice in many intensive care units (ICUs). Subsequent results on this practice have been variable, and recently some have demonstrated that POC glucometers have variable accuracy, particularly if hematocrit values are less than 25%. At our institution, adult ICU insulin infusion protocols may result in hypoglycemia as we base our therapy on POC glucometer results that may be significantly different from laboratory values. METHOD: Our sample included cardiac surgery patients on postoperative day 0. Study participants had to have an arterial catheter in place and have ordered morning laboratory tests, including a renal function set and a complete blood cell count. A single sample of arterial blood was collected and analyzed both by the nurse at the bedside with the Precision XCeedPro glucometer to obtain a POC glucose value and in the OHSU hospital&AElig;s laboratory with the Beckman Coulter DXC 800 and LH 780 machines. The POC glucose value, the laboratory glucose value, and the hematocrit data were recorded along with demographic data. Data analysis included descriptive statistics, a paired t test to compare the mean differences, and Spearman correlation. RESULTS: In our preliminary analysis, data were collected from 41 adults; mean age was 61.2 years (SD 13.2), 39 (95%), were white, 27 (66%) were male, and 28 (68%) had undergone coronary artery bypass grafting. Mean hematocrit was 27.4 (SD 4.9), mean POC glucose was 110.3 mg/dL (SD, 29), and mean laboratory glucose was 97.2 mg/dL (SD, 25.1). The mean difference between POC and laboratory glucose was 13.2 mg/dL (SD, 9.8), with POC glucose the higher value. Difference scores ranged from 33 mg/dL to - 7 mg/dL. A paired t test revealed t = 8.6, P < .001. Nonparametric correlation was used because hematocrit was not normally distributed; the Spearman rho correlation between the difference scores and hematocrit was - 0.36, P = .02. CONCLUSIONS: These findings demonstrate that substantial differences may occur with POC and laboratory testing of blood glucose on identical samples, raising concerns about the safety and appropriateness of tight glycemic control in postoperative cardiothoracic surgery patients. The difference between POC and laboratory measurements of glucose was inversely related to hematocrit, suggesting that patients with postoperative anemia are at greater risk for hypoglycemia.en_GB
dc.date.available2011-10-26T19:18:23Z-
dc.date.issued2011-10-26en_GB
dc.date.accessioned2011-10-26T19:18:23Z-
dc.identifier.citation2010 National Teaching Institute Research Abstracts. American Journal of Critical Care, 19(3), e15-e28. doi:10.4037/ajcc2010866en_GB
dc.conference.date2010en_GB
dc.conference.nameNational Teaching Institute and Critical Care Expositionen_GB
dc.conference.hostAmerican Association of Critical-Care Nursesen_GB
dc.conference.locationWashington, D.C., USAen_GB
dc.identifier.citation2010 National Teaching Institute Research Abstracts. American Journal of Critical Care, 19(3), e15-e28. doi:10.4037/ajcc2010866en_GB
dc.description.noteThis is an abstract-only submission. If the author has submitted a full-text item based on this abstract, you may find it by browsing the Virginia Henderson Global Nursing e-Repository by author. If author contact information is available in this abstract, please feel free to contact him or her with your queries regarding this submission. Alternatively, please contact the conference host, journal, or publisher (according to the circumstance) for further details regarding this item. If a citation is listed in this record, the item has been published and is available via open-access avenues or a journal/database subscription. Contact your library for assistance in obtaining the as-published article.-
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