scholarly journals Continuous Measurement of Blood Glucose

2011 ◽  
Vol 114 (1) ◽  
pp. 120-125 ◽  
Author(s):  
Nils K. Skjaervold ◽  
Erik Solligård ◽  
Dag R. Hjelme ◽  
Petter Aadahl
Keyword(s):  
Blood Glucose ◽  
Glucose Sensor ◽  
Blood Glucose Control ◽  
Mean Value ◽  
Blood Gas ◽  
Limits Of Agreement ◽  
Intravenous Glucose ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Wide Range

Background Tight blood glucose control is used extensively in perioperative and critically ill patients. Several studies, however, have shown contradictory effects on patient outcomes. A major problem of these studies has been inadequate control of the prime variable, blood glucose. This paper describes the validation of a new intravascular continuous blood glucose sensor. Methods The glucose sensor was placed in the superior caval vein of seven anesthetized pigs. Sensor readings were compared with arterial blood gas readings. Fluctuations in blood glucose were created using intravenous glucose and insulin. A total of 807 paired sensor and blood gas readings were obtained. Results The sensor was tested with a range of blood glucose values (0.63-15.75 mM [mean bias, 0.0131 mM]). Analysis using Bland-Altman plots yielded 95% limits of agreement at -0.908 and 0.934 mM. There were 121 paired measurements with a mean value below 2.2 mM, yielding 95% limits of agreement at -0.553 and 0.466 mM. Conclusions The performance of the sensor was in agreement with blood gas measurements in a wide range of glucose values. For the clinician, it is noteworthy that performance was equally good in the hypoglycemic area.

scholarly journals Agreement between arterial and capillary pH, pCO2 and lactate in patients in the emergency department

2020 ◽  
Author(s):  
V. Collot ◽  
S. Malinverni ◽  
E. Schweitzer ◽  
J. Haltout ◽  
P. Mols ◽  
...  
Keyword(s):  
Lactic Acidosis ◽  
Sensitivity And Specificity ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Mean Difference ◽  
Blood Gas ◽  
Limits Of Agreement ◽  
Study Objective ◽  
Arterial Blood Gas ◽  
Arterial Blood

AbstractStudy objectiveThe primary objective of the study was a quantitative analysis to assess the mean difference and 95% confidence interval of the difference between capillary and arterial blood gas analyses for pH, pCO2 and lactate. Secondary objective was to measure the sensitivity and specificity of capillary samples to detect altered pH, hypercarbia and lactic acidosis.MethodsAdults admitted to the ED for whom the treating physician deemed necessary an arterial blood gas analysis (BGA) were screened for inclusion. Simultaneous arterial and capillary samples were drawn for BGA. Agreement between the two methods for pH, pCO2 and lactate were studied with Bland-Altman bias plot analysis. Sensitivity, specificity, positive and negative predictive value as well as AUC were calculated for the ability of capillary samples to detect pH values outside normal ranges, hypercarbia and hyperlactatemia.Results197 paired analyses were included in the study. Mean difference for pH, between arterial and capillary BGA was 0.0095, 95% limits of agreement were -0.048 to 0.067. For pCO2, mean difference was -0.3 mmHg, 95% limits of agreement were -8.5 to 7.9 mmHg. Lactate mean difference was -0.93 mmol/L, 95% limits of agreement were -2.7 to 0.8 mmol/L. At a threshold of 7.34 for capillary pH had 98% sensitivity and 97% specificity to detect acidemia; at 45.9 mmHg capillary pCO2 had 89% sensitivity and 96% specificity to detect hypercarbia. Finally at a threshold of 3.5 mmol/L capillary lactate had 66% sensitivity to detect lactic acidosis.ConclusionCapillary measures of pH, pCO2 and lactate can’t replace arterial measurements although there is high concordance between the two methods for pH and pCO2 and moderate concordance for lactate. Capillary blood gas analysis had good accuracy when used as a screening tool to detect altered pH and hypercarbia but insufficient sensitivity and specificity when screening for lactic acidosis.

scholarly journals Beyond PaO2: Relationships between Indices of Pulmonary Oxygen Transfer in Hospitalized Adults Undergoing Blood Gas Testing

2019 ◽  
Vol 4 (03) ◽  
Author(s):  
Mark Feldman, MD ◽  
Denise Rebel, BS, RRT
Keyword(s):  
Oxygen Transfer ◽  
Supplemental Oxygen ◽  
Blood Gas ◽  
Limited Information ◽  
Partial Pressure Of Oxygen ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Wide Range ◽  
Breathing Room ◽  
Supplemental Oxygen Therapy

The arterial partial pressure of oxygen in the arterial blood reveals limited information about pulmonary oxygen transfer. In 989 hospitalized patients undergoing arterial blood gas testing, we compared conventional indices of oxygen transfer: (1) P(A-a) O2 (A-a); (2) PaO2/PAO2 (a/A); and (3) the P/F ratio Nine hundred twenty-five of the patients were receiving supplemental oxygen therapy (FIO2 .24-1.00) and 65 were breathing room air. In patients receiving supplemental O2, the a/A ratio closely correlated with the P/F ratio (r = .98 to .99); the A-a O2 difference did not correlate as closely with the a/A ratio (r = -.77 to -.85) or with the P/F ratio (r = -.72 to -.80). In those breathing room air (FIO2 .21), the a/A ratio was closely and inversely correlated with the A-a difference (r= -.97 to -.98); correlations between the a/A and P/F ratios (r=.88 to .89) and between the P/F ratio and A-a O2 difference (r = -.78 to -.79) were less robust. We conclude that the a/A ratio is the preferred oxygen transfer parameter over the wide range of FIO2 levels encountered clinically.

scholarly journals A multicentre prospective observational study comparing arterial blood gas values to those obtained by pulse oximeters used in adult patients attending Australian and New Zealand hospitals

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Janine Pilcher ◽  
Laura Ploen ◽  
Steve McKinstry ◽  
George Bardsley ◽  
Jimmy Chien ◽  
...  
Keyword(s):  
New Zealand ◽  
Pulse Oximetry ◽  
Accurate Method ◽  
Blood Gas ◽  
Limits Of Agreement ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
High Dependency ◽  
Clinically Significant ◽  
Clinical Trials Registry

Abstract Background Pulse oximetry is widely used in the clinical setting. The purpose of this validation study was to investigate the level of agreement between oxygen saturations measured by pulse oximeter (SpO2) and arterial blood gas (SaO2) in a range of oximeters in clinical use in Australia and New Zealand. Methods Paired SpO2 and SaO2 measurements were collected from 400 patients in one Australian and two New Zealand hospitals. The ages of the patients ranged from 18 to 95 years. Bias and limits of agreement were estimated. Sensitivity and specificity for detecting hypoxaemia, defined as SaO2 < 90%, were also estimated. Results The majority of participants were recruited from the Outpatient, Ward or High Dependency Unit setting. Bias, oximeter-measured minus arterial blood gas-measured oxygen saturation, was − 1.2%, with limits of agreement − 4.4 to 2.0%. SpO2 was at least 4% lower than SaO2 for 10 (2.5%) of the participants and SpO2 was at least 4% higher than the SaO2 in 3 (0.8%) of the participants. None of the participants with a SpO2 ≥ 92% were hypoxaemic, defined as SaO2 < 90%. There were no clinically significant differences in oximetry accuracy in relation to clinical characteristics or oximeter brand. Conclusions In the majority of the participants, pulse oximetry was an accurate method to assess SaO2 and had good performance in detecting hypoxaemia. However, in a small proportion of participants, differences between SaO2 and SpO2 could have clinical relevance in terms of patient monitoring and management. A SpO2 ≥ 92% indicates that hypoxaemia, defined as a SaO2 < 90%, is not present. Trial registration Australian and New Zealand Clinical Trials Registry (ACTRN12614001257651). Date of registration: 2/12/2014.

scholarly journals Working accuracy of pulse oximetry in COVID-19 patients stepping down from intensive care: a clinical evaluation

2020 ◽  
Vol 7 (1) ◽  
pp. e000778
Author(s):  
Keir Elmslie James Philip ◽  
Benjamin Bennett ◽  
Silas Fuller ◽  
Bradley Lonergan ◽  
Charles McFadyen ◽  
...  
Keyword(s):  
Intensive Care ◽  
Pulse Oximetry ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Blood Gas ◽  
Limits Of Agreement ◽  
Arterial Blood Gas ◽  
Paired Samples ◽  
Arterial Blood ◽  
Step Down

IntroductionUK guidelines suggest that pulse oximetry, rather than blood gas sampling, is adequate for monitoring of patients with COVID-19 if CO2 retention is not suspected. However, pulse oximetry has impaired accuracy in certain patient groups, and data are lacking on its accuracy in patients with COVID-19 stepping down from intensive care unit (ICU) to non-ICU settings or being transferred to another ICU.MethodsWe assessed the bias, precision and limits of agreement using 90 paired SpO2 and SaO2 from 30 patients (3 paired samples per patient). To assess the agreement between pulse oximetry (SpO2) and arterial blood gas analysis (SaO2) in patients with COVID-19, deemed clinically stable to step down from an ICU to a non-ICU ward, or be transferred to another ICU. This was done to evaluate whether the guidelines were appropriate for our setting.ResultsMean difference between SaO2 and SpO2 (bias) was 0.4%, with an SD of 2.4 (precision). The limits of agreement between SpO2 and SaO2 were as follows: upper limit of 5.2% (95% CI 6.5% to 4.2%) and lower limit of −4.3% (95% CI −3.4% to −5.7%).ConclusionsIn our setting, pulse oximetry showed a level of agreement with SaO2 measurement that was slightly suboptimal, although within acceptable levels for Food and Drug Authority approval, in people with COVID-19 judged clinically ready to step down from ICU to a non-ICU ward, or who were being transferred to another hospital’s ICU. In such patients, SpO2 should be interpreted with caution. Arterial blood gas assessment of SaO2 may still be clinically indicated.

Aberrant PO2 values in proficiency testing

1993 ◽  
Vol 39 (3) ◽  
pp. 467-471
Author(s):  
C E Fonzi ◽  
J L Clausen ◽  
J Mahoney
Keyword(s):  
Proficiency Testing ◽  
Repeated Measures ◽  
Mean Value ◽  
Repeated Measurements ◽  
Blood Gas ◽  
Mean Values ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Fluorocarbon Emulsion ◽  
The Mean

Abstract We prospectively determined the frequency of aberrant vials of fluorocarbon/buffer used for proficiency testing of measurements of pH, PCO2, and PO2, using 20 duplicate vials from 12 lots of fluorocarbon/buffer and two arterial blood gas analyzers in eight reference laboratories. We defined aberrant vials as vials for which both duplicate measurements differed from the mean value of repeated measurements for the specific instrument (for each lot of testing materials) by &gt; 0.04 for pH, &gt; 10% of the mean or 3.0 mm Hg, whichever was greater, for PCO2; or &gt; 10% of the mean or 6 mm Hg, whichever was greater, for PO2. Four of 1620 vials (0.25%) were aberrant, all based on PO2 measurements (&lt; 70 mm Hg); all would have failed in both American/California Thoracic Societies and College of American Pathologists proficiency programs. The average intra-instrument SDs of repeated measures (range of mean values: pH, 7.181-7.631; PCO2, 12.7-65.9; PO2, 32.5-150.1) were 0.0055 for pH, 0.67 mm Hg for PCO2, and 1.65 mm Hg for PO2. Deliberate contamination of the fluorocarbon emulsion with room air, as might occur during sampling from the vial, indicated that only minor increases in PO2 (e.g., 1.0 mm Hg at PO2 of 56 mm Hg) occur when samples are aspirated. Larger increases in PO2 (mean 7.1 mm Hg at a PO2 of 66 mm Hg) occurred when the syringe samples were contaminated with room air. We conclude that isolated aberrant measurements of PO2 in blood gas proficiency testing attributable to vial contents can occur, but the frequency is very low.

Accuracy of transcutaneous carbon dioxide monitoring in hypotensive patients

2013 ◽  
Vol 31 (4) ◽  
pp. 323-326 ◽  
Author(s):  
Jung-Youn Kim ◽  
Young-Hoon Yoon ◽  
Sung-Woo Lee ◽  
Sung-Hyuk Choi ◽  
Young-Duck Cho ◽  
...  
Keyword(s):  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Mean Difference ◽  
Blood Gas ◽  
Limits Of Agreement ◽  
Arterial Blood Gas ◽  
Blood Gas Monitoring ◽  
Arterial Blood ◽  
Arterial Blood Gas Analysis ◽  
The Mean

ObjectivesContinuous blood gas monitoring is frequently necessary in critically ill patients. Our aim was to assess the accuracy of transcutaneous CO2 tension (PtcCO2) monitoring in the emergency department (ED) assessment of hypotensive patients by comparing it with the gold standard of arterial blood gas analysis (ABGA).MethodsAll patients receiving PtcCO2 monitoring in the ED were included. We excluded paediatric patients, patients with no ABGA results during a hypotensive event, patients whose ABGA was not performed simultaneously with PtcCO2 monitoring, and patients who received sodium bicarbonate for resuscitation. The included patients were classified into hypotensive patients and normotensive patients. A hypotensive patient was defined as a patient showing a mean arterial pressure under 60 mm Hg. The agreement in measurement between PaCO2 tension (PaCO2) and PtcCO2 were investigated in both groups.ResultsThe mean difference between PaCO2 and PtcCO2 was 2.1 mm Hg, and the Bland–Altman limits of agreement (bias±1.96 SD) ranged from −15.6 to 19.7 mm Hg in the 28 normotensive patients. The mean difference between PaCO2 and PtcCO2 was 1.1 mm Hg, and the Bland–Altman limits of agreement (bias±1.96 SD) ranged from −19.5 to 21.7 mm Hg in the 26 hypotensive patients. The weighted κ values were 0.64 in the normotensive patients and 0.60 in the hypotensive patients.ConclusionsPtcCO2 monitoring showed wider limits of agreement with PaCO2 in urgent situations in the ED environment. However, acutely developed hypotension does not affect the accuracy of PtcCO2 monitoring.

Agreement between paired blood gas values in samples transported either by a pneumatic system or by human courier

2011 ◽  
Vol 49 (8) ◽  
Author(s):  
John Victor Peter ◽  
Shalom Patole ◽  
Jude Joseph Fleming ◽  
Ratnasamy Selvakumar ◽  
Petra L. Graham
Keyword(s):  
Accurate Assessment ◽  
Blood Gas ◽  
Study Analysis ◽  
Concordance Correlation ◽  
Tube System ◽  
Limits Of Agreement ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
The Mean ◽  
Pneumatic Tube System

AbstractRapid accurate assessment of metabolic derangements is crucial in the critically ill. We evaluated if arterial blood gas (ABG) samples transported through a pneumatic tube system (PTS) agreed with values transported by a human courier.In this prospective study of 50-paired ABG samples, the couriered reference ABG was compared with those transported by PTS. Agreement was summarised by the mean difference with 95% limits of agreement (LOA) and Lin's concordance correlation (The mean (±SD) time from sampling to analysis was 35.7±23.2 (courier) and 38.6±22.1 (PTS) minutes. Agreement was good between courier and PTS for pH, PaCOIn this study, analysis of samples transported through the PTS resulted in clinically unacceptable PaO

scholarly journals Five-Year Two-Center Retrospective Comparison of Central Laboratory Glucose to GEM 4000 and ABL 800 Blood Glucose: Demonstrating the (In)adequacy of Blood Gas Glucose

2019 ◽  
Vol 14 (3) ◽  
pp. 535-545
Author(s):  
George Cembrowski ◽  
Joanna Jung ◽  
Junyi Mei ◽  
Eric Xu ◽  
Tihomir Curic ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Time Of Day ◽  
Guidance Document ◽  
Blood Gas ◽  
Central Laboratory ◽  
Data Repositories ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Minute Interval ◽  
Average Patient

Purpose: To evaluate the glucose assays of two blood gas analyzers (BGAs) in intensive care unit (ICU) patients by comparing ICU BGA glucoses to central laboratory (CL) glucoses of almost simultaneously drawn specimens. Methods: Data repositories provided five years of ICU BGA glucoses and contemporaneously drawn CL glucoses from a Calgary, Alberta ICU equipped with IL GEM 4000 and CL Roche Cobas 8000-C702, and an Edmonton, Alberta ICU equipped with Radiometer ABL 800 and CL Beckman-Coulter DxC. Blood glucose analyzer and CL glucose differences were evaluated if they were both drawn either within ±15 or ±5 minutes. Glucose differences were assessed graphically and quantitatively with simple run charts and the surveillance error grid (SEG) and quantitatively with the 2016 Food and Drug Administration guidance document, with ISO 15197 and SEG statistical summaries. As the GEM glucose exhibits diurnal variation, CL-arterial blood gas (ABG) differences were evaluated according to time of day. Results: Compared to the GEM glucoses measured between 0200 and 0800, the run charts of (GEM-CL) glucose demonstrate significant outliers between 0800 and 0200 which are identified as moderate to severe clinical outliers by SEG analysis ( P < .002 and P < .0005 for 5- and 15-minute intervals). Over the entire 24-hour period, the rates of moderate to severe glucose clinical outliers are 3.5/1000 (GEM) and 0.6/1000 glucoses (ABL), respectively, using the 15-minute interval ( P < .0001). Discussion: The GEM ABG glucose is associated with a higher frequency of moderate to severe glucose clinical outliers, especially between 0800 and 0200, increased CL testing and higher average patient glucoses.

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