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A P Shepherd - One of the best experts on this subject based on the ideXlab platform.
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co oximetry interference by hemoglobin based blood substitutes
Anesthesia & Analgesia, 2001Co-Authors: Aaron Ashoka Ali, Genevieve Shepherd Ali, J M Steinke, A P ShepherdAbstract:The blood substitutes now being developed from molecularly modified hemoglobin interfere with a wide variety of clinical analyzers, but their effects on cooximeters are unknown. Therefore, we investigated the effects of five hemoglobin-based blood substitutes on the measurements of eight different oximeters and cooximeters: the AVL Omni 6, the AVOXimeters 1000 and 4000, the Ciba Corning (now Bayer) CC270 CO-oximeter, the Instrumentation Laboratory Synthesis 35, the IL482 and IL682 CO-oximeters, and the Radiometer OSM3 Hemoximeter. The five blood substitutes in this study were obtained from Apex Bioscience (Research Triangle Park, NC), Baxter Healthcare Corp. (Deerfield, IL), Biopure Corp. (Cambridge, MA), Hemoglobin Therapeutics, and Hemosol, Inc. (Etobicoke, Ontario, Canada). A cooximeter control was used to compare the eight different instruments’ measurements on unaltered human hemoglobin. The instruments yielded measurements of total hemoglobin concentration in undiluted blood substitutes that were generally not more variable than those on the control material. By contrast, when compared with readings on controls, the test instruments yielded measurements of the fractional concentrations of oxy-, deoxy-, carboxy-, and methemoglobin that showed greater instrument-to-instrument disparities and larger standard deviations about the all-instrument means. In some cases, the interference was even more obvious: five of six cooximeters gave negative carboxyhemoglobin readings on one particular product. Our findings indicate that the instruments will give less accurate but clinically useful measurements in the presence of these hemoglobin-based blood substitutes.
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co oximetry interference by hemoglobin based blood substitutes
Anesthesia & Analgesia, 2001Co-Authors: J M Steinke, A P ShepherdAbstract:UNLABELLED: The blood substitutes now being developed from molecularly modified hemoglobin interfere with a wide variety of clinical analyzers, but their effects on cooximeters are unknown. Therefore, we investigated the effects of five hemoglobin-based blood substitutes on the measurements of eight different oximeters and cooximeters: the AVL Omni 6, the AVOXimeters 1000 and 4000, the Ciba Corning (now Bayer) CC270 CO-oximeter, the Instrumentation Laboratory Synthesis 35, the IL482 and IL682 CO-oximeters, and the Radiometer OSM3 Hemoximeter. The five blood substitutes in this study were obtained from Apex Bioscience (Research Triangle Park, NC), Baxter Healthcare Corp. (Deerfield, IL), Biopure Corp. (Cambridge, MA), Hemoglobin Therapeutics, and Hemosol, Inc. (Etobicoke, Ontario, Canada). A cooximeter control was used to compare the eight different instruments' measurements on unaltered human hemoglobin. The instruments yielded measurements of total hemoglobin concentration in undiluted blood substitutes that were generally not more variable than those on the control material. By contrast, when compared with readings on controls, the test instruments yielded measurements of the fractional concentrations of oxy-, deoxy-, carboxy-, and methemoglobin that showed greater instrument-to-instrument disparities and larger standard deviations about the all-instrument means. In some cases, the interference was even more obvious: five of six cooximeters gave negative carboxyhemoglobin readings on one particular product. Our findings indicate that the instruments will give less accurate but clinically useful measurements in the presence of these hemoglobin-based blood substitutes. IMPLICATIONS: We investigated the effects of five hemoglobin-based blood substitutes on the measurements of eight different cooximeters. Some blood substitutes caused obvious interference, such as negative carboxyhemoglobin readings; however, the findings indicate that cooximeters will generally give less accurate but clinically useful measurements in the presence of the hemoglobin-based blood substitutes that were tested.
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Effects of carboxyhemoglobin on hemoglobinometers.
Clinical chemistry, 2000Co-Authors: A P Shepherd, John M. Steinke, Alice K GongAbstract:During a recent comparison of two portable hemoglobinometers designed for near-patient testing, we noted disparate readings on a quality-control material derived from human hemoglobin (Level 1, Multi-4® CO-oximeter Controls; Instrumentation Laboratory). The insert sheet listed an acceptable range of total hemoglobin readings of 159–185 g/L (15.9–18.5 g/dL) for the OSM3 CO-oximeter (Radiometer A/S). Our results on the OSM3 were at the midpoint of this range, as were results with one of the hemoglobinometers, the Hb-Quick® hemoglobinometer from Avox Systems [mean (SD), 175 (0.5) g/L; n = 5]. By contrast, readings on a HemoCue hemoglobinometer (HemoCue AB) were 16 g/L higher than the mid-range value and averaged 188 ± 1.5 g/L. Both hemoglobinometers had recently been calibrated by factory-trained employees of the respective companies. Because Level 1 controls contained ∼60% carboxyhemoglobin, we made additional measurements on fresh whole blood from a nonsmoking donor and on …
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CO-Oximetry interference by perflubron emulsion: comparison of hemolyzing and nonhemolyzing instruments
Clinical chemistry, 1998Co-Authors: A P Shepherd, John M. SteinkeAbstract:Perflubron emulsion is expected to be in clinical use soon as a non-hemoglobin blood substitute. A preliminary report indicates that this new oxygen-carrying fluorocarbon interferes with the measurements of CO-oximeters. Therefore, we have quantified the interference that perflubron causes in the measurements of eight widely used oximeters and CO-oximeters. The AVL Omni 6, CC270, IL482, IL682, and OSM3 are conventional CO-oximeters that hemolyze blood samples before analyzing them. In contrast, the AVOXimeters 1000 and 4000 and the IL Synthesis 35 make their measurements without hemolyzing the samples. Because perflubron is expected to be used most frequently on surgical patients in a hemodiluted state, we conducted all tests on human erythrocytes suspended in plasma at a hemoglobin concentration standardized to 70 g/L (7 g/dL) and with oxyhemoglobin saturation set at 97%. When perflubron was added to the blood samples, the nonhemolyzing CO-oximeters were not seriously affected by perflubron concentrations in and above the therapeutic range. In contrast, some of the hemolyzing CO-oximeters experienced concentration-dependent interference in their measurements of all analytes except total hemoglobin concentration. Thus, we conclude that the nonhemolyzing CO-oximeters provide an effective means for determining whether a hemolyzing CO-oximeter is experiencing clinically important interference in blood from patients receiving perflubron.
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Effects of temperature on optical absorbance spectra of oxy-, carboxy-, and deoxyhemoglobin.
Clinical chemistry, 1992Co-Authors: John M. Steinke, A P ShepherdAbstract:The optical absorbance spectra of oxy-, carboxy-, and deoxyhemoglobin were recorded at wavelengths from 479 to 651 nm and at temperatures of 20, 30, and 40 degrees C. As noted in earlier reports, a major effect of lowering the temperature was an increase in the absorptivities at or near the absorbance maxima. However, at other wavelengths, reducing the temperature increased, decreased, or caused no change in absorbance. At wavelengths where temperature-induced shifts did occur, the absorbance change appeared to be a linear function of temperature. Unlike previous reports, the data presented here are quantitative and thus can be used to predict temperature-induced errors in spectrophotometric measurements of the relative concentrations of these hemoglobin species. Examples are given of the error that would occur in a widely used CO-oximeter, the IL482, if it were not temperature controlled. Thus, the data presented here should be particularly useful to the operators and designers of spectrophotometric instruments such as oximeters, CO-oximeters, and hemoglobinometers.
C Junghans - One of the best experts on this subject based on the ideXlab platform.
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evaluation of point of care haemoglobin measuring devices a comparison of radical 7 pulse co oximetry hemocue and laboratory haemoglobin measurements in obstetric patients
Anaesthesia, 2013Co-Authors: V Skelton, N Wijayasinghe, S Sharafudeen, A Sange, N Parry, C JunghansAbstract:: We prospectively compared two point-of-care haemoglobin concentration measuring devices with laboratory measurements to determine their accuracy in women undergoing caesarean section delivery. The two devices were the Masimo Rainbow SET(®) Radical -7™ pulse CO-oximeter and the HemoCue(®) HB 201+, which is a cuvette-type system that uses photometry. CO-oximeter readings and HemoCue measurements were taken before and after surgery, and compared with laboratory measurements of haemoglobin concentration taken at the same time. We analysed data from 137 patients using Bland-Altman plots. Limits of agreement for CO-oximeter readings were -2.19 to 3.41 g.dl(-1) and for the HemoCue were -1.52 to 1.79 g.dl(-1) . The bias (mean difference) for the CO-oximeter was -0.61 g.dl(-1) (95% CI 0.36 to -0.86) and for the HemoCue was 0.13 g.dl(-1) (95% CI -0.015 to 0.28). [corrected] Overall, 110/274 (40%) CO-oximeter readings were within 1 g.dl(-1) of laboratory values compared with 247/274 (90%) HemoCue measurements (p < 0.001 for difference). The CO-oximeter gave lower readings and was less accurate than the HemoCue system when compared with laboratory measurements.
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Evaluation of point‐of‐care haemoglobin measuring devices: a comparison of Radical‐7™ pulse co‐oximetry, HemoCue® and laboratory haemoglobin measurements in obstetric patients*
Anaesthesia, 2012Co-Authors: V. A. Skelton, N Wijayasinghe, S Sharafudeen, A Sange, N. S. Parry, C JunghansAbstract:We prospectively compared two point-of-care haemoglobin concentration measuring devices with laboratory measurements to determine their accuracy in women undergoing caesarean section delivery. The two devices were the Masimo Rainbow SET(®) Radical -7™ pulse CO-oximeter and the HemoCue(®) HB 201+, which is a cuvette-type system that uses photometry. CO-oximeter readings and HemoCue measurements were taken before and after surgery, and compared with laboratory measurements of haemoglobin concentration taken at the same time. We analysed data from 137 patients using Bland-Altman plots. Limits of agreement for CO-oximeter readings were -2.19 to 3.41 g.dl(-1) and for the HemoCue were -1.52 to 1.79 g.dl(-1) . The bias (mean difference) for the CO-oximeter was -0.61 g.dl(-1) (95% CI 0.36 to -0.86) and for the HemoCue was 0.13 g.dl(-1) (95% CI -0.015 to 0.28). [corrected] Overall, 110/274 (40%) CO-oximeter readings were within 1 g.dl(-1) of laboratory values compared with 247/274 (90%) HemoCue measurements (p
Donald P. Tashkin - One of the best experts on this subject based on the ideXlab platform.
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Arterial Blood Gas Reference Values for Sea Level and an Altitude of 1,400 Meters
2013Co-Authors: Robert O. Crapo, Robert L. Jensen, Mathew Hegewald, Donald P. TashkinAbstract:Blood gas measurements were collected on healthy lifetime nonsmokers at sea level (n � 96) and at an altitude of 1,400 meters (n � 243) to establish reference equations. At each study site, arterial blood samples were analyzed in duplicate on two separate blood gas analyzers and CO-oximeters. Arterial blood gas variables included Pa O2, Pa CO2, pH, and calculated alveolar-arterial PO 2 difference (AaPO 2). CO-oximeter variables were Hb, COHb, MetHb, and Sa O2. Subjects were 18 to 81 yr of age with 166 male and 173 female. Outlier data were excluded from multiple regression analysis, and reference equations were fitted to the data in two ways: (1) best fit using linear, squared, and crossproduct terms; (2) simple equations, including only the variables that explained at least 3 % of the variance. Two sets of equations were created: (1) using only the sea level data and (2) using the combined data with barometric pressure as an independent variable. Comparisons with earlier studies revealed small but significant differences; the decline in Pa O2 with age at each altitude was consistent with most previous studies. At sea level, the equation that included barometric pressure predicted Pa O2 slightly better than the sea level specific equation. The inclusion of barometric pressure in the equations allows better prediction of blood gas reference values at sea level and at altitudes as high as 1,400 meters. Crapo RO, Jensen RL, Hegewald M, Tashkin DP. Arterial blood gas referenc
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arterial blood gas reference values for sea level and an altitude of 1 400 meters
American Journal of Respiratory and Critical Care Medicine, 1999Co-Authors: Robert O. Crapo, Robert L. Jensen, Mathew Hegewald, Donald P. TashkinAbstract:Blood gas measurements were collected on healthy lifetime nonsmokers at sea level (n = 96) and at an altitude of 1,400 meters (n = 243) to establish reference equations. At each study site, arterial blood samples were analyzed in duplicate on two separate blood gas analyzers and CO-oximeters. Arterial blood gas variables included Pa(O(2)), Pa(CO(2)), pH, and calculated alveolar-arterial PO(2) difference (AaPO(2)). CO-oximeter variables were Hb, COHb, MetHb, and Sa(O(2)). Subjects were 18 to 81 yr of age with 166 male and 173 female. Outlier data were excluded from multiple regression analysis, and reference equations were fitted to the data in two ways: (1) best fit using linear, squared, and cross-product terms; (2) simple equations, including only the variables that explained at least 3% of the variance. Two sets of equations were created: (1) using only the sea level data and (2) using the combined data with barometric pressure as an independent variable. Comparisons with earlier studies revealed small but significant differences; the decline in Pa(O(2)) with age at each altitude was consistent with most previous studies. At sea level, the equation that included barometric pressure predicted Pa(O(2)) slightly better than the sea level specific equation. The inclusion of barometric pressure in the equations allows better prediction of blood gas reference values at sea level and at altitudes as high as 1,400 meters.
J M Steinke - One of the best experts on this subject based on the ideXlab platform.
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co oximetry interference by hemoglobin based blood substitutes
Anesthesia & Analgesia, 2001Co-Authors: Aaron Ashoka Ali, Genevieve Shepherd Ali, J M Steinke, A P ShepherdAbstract:The blood substitutes now being developed from molecularly modified hemoglobin interfere with a wide variety of clinical analyzers, but their effects on cooximeters are unknown. Therefore, we investigated the effects of five hemoglobin-based blood substitutes on the measurements of eight different oximeters and cooximeters: the AVL Omni 6, the AVOXimeters 1000 and 4000, the Ciba Corning (now Bayer) CC270 CO-oximeter, the Instrumentation Laboratory Synthesis 35, the IL482 and IL682 CO-oximeters, and the Radiometer OSM3 Hemoximeter. The five blood substitutes in this study were obtained from Apex Bioscience (Research Triangle Park, NC), Baxter Healthcare Corp. (Deerfield, IL), Biopure Corp. (Cambridge, MA), Hemoglobin Therapeutics, and Hemosol, Inc. (Etobicoke, Ontario, Canada). A cooximeter control was used to compare the eight different instruments’ measurements on unaltered human hemoglobin. The instruments yielded measurements of total hemoglobin concentration in undiluted blood substitutes that were generally not more variable than those on the control material. By contrast, when compared with readings on controls, the test instruments yielded measurements of the fractional concentrations of oxy-, deoxy-, carboxy-, and methemoglobin that showed greater instrument-to-instrument disparities and larger standard deviations about the all-instrument means. In some cases, the interference was even more obvious: five of six cooximeters gave negative carboxyhemoglobin readings on one particular product. Our findings indicate that the instruments will give less accurate but clinically useful measurements in the presence of these hemoglobin-based blood substitutes.
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co oximetry interference by hemoglobin based blood substitutes
Anesthesia & Analgesia, 2001Co-Authors: J M Steinke, A P ShepherdAbstract:UNLABELLED: The blood substitutes now being developed from molecularly modified hemoglobin interfere with a wide variety of clinical analyzers, but their effects on cooximeters are unknown. Therefore, we investigated the effects of five hemoglobin-based blood substitutes on the measurements of eight different oximeters and cooximeters: the AVL Omni 6, the AVOXimeters 1000 and 4000, the Ciba Corning (now Bayer) CC270 CO-oximeter, the Instrumentation Laboratory Synthesis 35, the IL482 and IL682 CO-oximeters, and the Radiometer OSM3 Hemoximeter. The five blood substitutes in this study were obtained from Apex Bioscience (Research Triangle Park, NC), Baxter Healthcare Corp. (Deerfield, IL), Biopure Corp. (Cambridge, MA), Hemoglobin Therapeutics, and Hemosol, Inc. (Etobicoke, Ontario, Canada). A cooximeter control was used to compare the eight different instruments' measurements on unaltered human hemoglobin. The instruments yielded measurements of total hemoglobin concentration in undiluted blood substitutes that were generally not more variable than those on the control material. By contrast, when compared with readings on controls, the test instruments yielded measurements of the fractional concentrations of oxy-, deoxy-, carboxy-, and methemoglobin that showed greater instrument-to-instrument disparities and larger standard deviations about the all-instrument means. In some cases, the interference was even more obvious: five of six cooximeters gave negative carboxyhemoglobin readings on one particular product. Our findings indicate that the instruments will give less accurate but clinically useful measurements in the presence of these hemoglobin-based blood substitutes. IMPLICATIONS: We investigated the effects of five hemoglobin-based blood substitutes on the measurements of eight different cooximeters. Some blood substitutes caused obvious interference, such as negative carboxyhemoglobin readings; however, the findings indicate that cooximeters will generally give less accurate but clinically useful measurements in the presence of the hemoglobin-based blood substitutes that were tested.
Robert O. Crapo - One of the best experts on this subject based on the ideXlab platform.
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Arterial Blood Gas Reference Values for Sea Level and an Altitude of 1,400 Meters
2013Co-Authors: Robert O. Crapo, Robert L. Jensen, Mathew Hegewald, Donald P. TashkinAbstract:Blood gas measurements were collected on healthy lifetime nonsmokers at sea level (n � 96) and at an altitude of 1,400 meters (n � 243) to establish reference equations. At each study site, arterial blood samples were analyzed in duplicate on two separate blood gas analyzers and CO-oximeters. Arterial blood gas variables included Pa O2, Pa CO2, pH, and calculated alveolar-arterial PO 2 difference (AaPO 2). CO-oximeter variables were Hb, COHb, MetHb, and Sa O2. Subjects were 18 to 81 yr of age with 166 male and 173 female. Outlier data were excluded from multiple regression analysis, and reference equations were fitted to the data in two ways: (1) best fit using linear, squared, and crossproduct terms; (2) simple equations, including only the variables that explained at least 3 % of the variance. Two sets of equations were created: (1) using only the sea level data and (2) using the combined data with barometric pressure as an independent variable. Comparisons with earlier studies revealed small but significant differences; the decline in Pa O2 with age at each altitude was consistent with most previous studies. At sea level, the equation that included barometric pressure predicted Pa O2 slightly better than the sea level specific equation. The inclusion of barometric pressure in the equations allows better prediction of blood gas reference values at sea level and at altitudes as high as 1,400 meters. Crapo RO, Jensen RL, Hegewald M, Tashkin DP. Arterial blood gas referenc
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arterial blood gas reference values for sea level and an altitude of 1 400 meters
American Journal of Respiratory and Critical Care Medicine, 1999Co-Authors: Robert O. Crapo, Robert L. Jensen, Mathew Hegewald, Donald P. TashkinAbstract:Blood gas measurements were collected on healthy lifetime nonsmokers at sea level (n = 96) and at an altitude of 1,400 meters (n = 243) to establish reference equations. At each study site, arterial blood samples were analyzed in duplicate on two separate blood gas analyzers and CO-oximeters. Arterial blood gas variables included Pa(O(2)), Pa(CO(2)), pH, and calculated alveolar-arterial PO(2) difference (AaPO(2)). CO-oximeter variables were Hb, COHb, MetHb, and Sa(O(2)). Subjects were 18 to 81 yr of age with 166 male and 173 female. Outlier data were excluded from multiple regression analysis, and reference equations were fitted to the data in two ways: (1) best fit using linear, squared, and cross-product terms; (2) simple equations, including only the variables that explained at least 3% of the variance. Two sets of equations were created: (1) using only the sea level data and (2) using the combined data with barometric pressure as an independent variable. Comparisons with earlier studies revealed small but significant differences; the decline in Pa(O(2)) with age at each altitude was consistent with most previous studies. At sea level, the equation that included barometric pressure predicted Pa(O(2)) slightly better than the sea level specific equation. The inclusion of barometric pressure in the equations allows better prediction of blood gas reference values at sea level and at altitudes as high as 1,400 meters.