Abstract
It is shown that microdialysis-based blood gas (pH, pCO2 and pO2) optical sensors are stable for durations of several hours in blood. This performance is uncommon with many types of membrane sensor. Microdialysis techniques can be designed to ensure that the sweep microflow samples are in biochemical equilibrium with the bulk media, even after hours of exposure to the complex composition of blood. The rate of diffusion through the membrane is not the determining factor in sensor reading, as it is with other sensor techniques that consume the analyte. The sweep fluid 95% equilibration times for microdialysis fibres were approximately double in blood compared with buffer, reflecting slower diffusion of ions. This is in contrast to the equilibration of gases through silicone hollow-fibre membranes in blood, which showed unchanged equilibration times between blood and buffer. Sensor measurements correlate well with a blood gas analyser for up to 9h in blood, with correlation coefficients of 0.973 for the pO2 sensor 0.974 for the pCO2 sensor and 0.947 for the pH sensor. In blood, the sensors have precisions of 1.7 mmHg, 3.7 mmHg and 0.019 pH units and bias levels of −0.7 mmHg, 1.2mmHg and 0.002pH units, for pO2, pCO2 and pH, respectively.
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Asimos, A., Gibbs, M., Marx, J., Jacobs, D., Erwin, R., Norton, J., andThomason, M. (2000): ‘Value of point-of-care blood testing in emergent trauma management’,J. Trauma,48, pp. 1101–1108
Bland, J., andAltman, D. (1986): ‘Statistical methods for assessing agreement between two methods of clinical measurement’,The Lancet,1, pp. 307–310
Bland, J., andAltman, D. (2003): ‘Applying the right statistics: analyses of measurement studies’,Ultrasound Obstet. Gynecol.,22, pp. 85–93
Cooney, C., andTowe, B. (1997): ‘Intravascular carbon dioxide monitoring using micro-flow colorimetry’,Biosens. Bioelectron.,12, pp. 11–17
Cooney, C., Towe, B., andEyster, C. (2000): ‘Optical pH, oxygen, and carbon dioxide monitoring using a microdialysis approach’,Sensors & Actuators B,69, pp. 183–188
Halpern, M., Palmer, C., Simpson, K., Chesley, F., Luce, B., Suyderhoud, J., Neibauer, B., andEstafanous, F. (1988): ‘The economic and clinical efficiency of point-of-care testing for critically ill patients: a decision-analysis model’,Am. J. Med. Qual.,13, pp. 3–12
Kyrolainen, M., Rigsby, P., Eddy, S., andVadgama, P. (1995): ‘Bio-/haemocompatibility: implications and outcomes for sensors?’Acta Anaesthesiol. Scand.,104, pp. 55–60
Prause, G., Ratzenhofer-Komenda, B., Offner, A., Lauda, P., Voit, H., andPojer, H. (1997): ‘Prehospital point of care testing of blood gases and electrolytes — an evaluation of IRMA’,Crit. Care,1, pp. 79–83
Seghatchian, M., Alfonso, M., andVickers, M. (1997): ‘Effect of pH and buffering condition on dMPV of three types of platelet concentrates’,Transfus. Sci.,18, pp. 109–113
Trager, S., Pignataro, M., Anderson, J., andKleinert, J. (1993): ‘Color-flow Doppler-imaging the upper extremity’,J. Hand Surg. Am. Vol.,18A, pp. 621–625
Vanderline, R., Goodwin, J., Koch, D., Scheer, D., Steindel, S., Cembrowski, G., andSchwartz, M. (1987): ‘Guidelines for providing quality state laboratory services’ (AACC Press, 1987)
Wolfbeis, O., andPosch, H. (1985): ‘Fiber optical fluorosensor for determination of halothane and/or oxygen’,Anal. Chem.,57, pp. 2556–2561
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Cooney, C.G., Towe, B.C. Evaluation of microfluidic blood gas sensors that combine microdialysis and optical monitoring. Med. Biol. Eng. Comput. 42, 720–724 (2004). https://doi.org/10.1007/BF02347556
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DOI: https://doi.org/10.1007/BF02347556