Abstract
Objective. Tissue pH measurement has a number of clinical applications, including the monitoring of both muscle pH and organ pH as an indicator of compromised blood flow and anaerobic metabolism. The objective of this work was to demonstrate the feasibility of a noninvasive measurement of deep tissue pH using near-infrared reflectance spectroscopy and multivariate calibration techniques.Methods. Six studies were done on five New Zealand white rabbits. Two pH electrodes were implanted in the teres major muscle and a vascular clamp placed across the single artery feeding the muscle. Reflected light was collected through the skin from a site between the two electrodes as the pH was lowered by closing the clamp and raised by opening the clamp. Partial least squares analysis with cross-validation techniques was used to relate pH to light absorption at 201 evenly spaced wavelengths between 700 and 1100 nm.Results. On average, the tissue, pH started at 7.13 ± 0.09 and decreased to 6.74 ± 0.09, returning to 7.13 ± 0.09 after reperfusion. Calibration models fit for each rabbit had an average of nine factors with an R2 of 0.98 and a prediction error of 0.016 ± 0.002 pH units.Conclusions. We believe this to be the firstin vivo demonstration of a noninvasive method for measuring tissue pH in skin-covered muscle using near-infrared reflectance spectroscopy and multivariate calibration techniques.
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References
Hampson NB, Piantadosi CA. Near infrared monitoring of human skeletal muscle oxygenation during forearm ischemia. J Appl Physiol 1988; 64: 2449–2457
Parsons WJ, Rembert JC, Bauman RP, Greenfield JC, Piantadosi CA. Dynamic mechanisms of cardiac oxygenation during brief ischemia and reperfusion. Am J Physiol 1990; 259: H1477-H1485
Dunn RM, Kaplan IB, Mancoll J, Terzis JK, TrengoveJones G. Experimental and clinical use of pH monitoring of free tissue transfers. Ann Plast Surg 1993; 31: 539–545
Khuri SF, Josa M, Marston W, Braunwald NS, Smith B, Tow D, VanCisin M, Barsamian EM. First report of intramyocardial pH in man. II. Assessment of adequacy of myocardial preservation. J Thorac Cardiovasc Surg 1983; 86: 667–678
Stahl RF, Soller BR, Hsi C, BelleIsle J, Vander Salm TJ. Falling myocardial pH reflects ischemia during continuous warm retrograde cardioplegic arrest. Ann Thorac Surg 1994; 58: 1645–1650
Neethling WML, van den Heever JJ, Cooper S, Meyer JM. Interstitial pH during myocardial preservation: Assessment of five methods of myocardial preservation. Ann Thorac Surg 1993; 55: 420–426
Haan C, Lazar HL, Bernard S, Rivers S, Zalnick J, Shemin RJ. Superiority of retrograde cardioplegia after acute coronary occlusion. Ann Thorac Surg 1991; 51: 408–412
Fiddian-Green RG. Associations between intramucosal acidosis in the gut and organ failure. Crit Care Med 1993; 21: S103-S107
Khuri SF, Marston W, Josa M, Crowe W, Macera R, Zierler M, Lange R, Miller W. First report of intramyocardial pH in man: I. Methodology and initial results. Med Instrum 1984; 18: 167–171
Thomas EV. A primer on multivariate calibration. Anal Chem 1994; 66 (15): 795A-804A
Robinson MR, Eaton RP, Haaland DM, Koepp GW, Thomas EV, Stallard BR, Robinson PL. Noninvasive glucose monitoring in diabetic patients: A preliminary evaluation. Clin Chem 1992; 38: 1618–1622
Haaland DM, Thomas EV. Partial least-squares methods for spectral analyses. 1. Relation to other quantitative calibration methods and the extraction of qualitative information. Anal Chem 1988; 60: 1193–1202
Haaland DM, Robinson MR, Koepp GW, Thomas EV, Eaton RP. Reagentless near-infrared determination of glucose in whole blood using multivariate calibration. Appl Spectrosc 1992; 46: 1575–1578
Wilson JR, Mancini DM, McCully K, Ferraro N, Lanoce V, Chance B. Noninvasive detection of skeletal muscle underperfusion with near-infrared spectroscopy in patients with heart failure. Circulation 1989; 80: 1668–1674
Martens H, Naes T. Multivariate calibration. Chichester: John Wiley & Sons; 1989
Isaksson T, Miller C, Naes T. Nondestructive NIR and NIT determination of protein, fat, and water in plastic-wrapped, homogenized meat. Appl Spectrosc 1992; 46: 1685
Drennen JK, Lodder RA. Nondestructive near-infrared analysis of intact tables for determination of degradation products. J Pharm Sci 1990; 79: 622–627
Hall JW, Pollard A. Near-infrared spectrophotometry: A new dimension in clinical chemistry. Clin Chem 1992; 38/9: 1623–1631
Carney JM, Landrum W, Mayes L, Zou Y, Lodder RA. Near-infrared spectrophotometric monitoring of stroke-related changes in the protein and lipid composition of whole gerbil brains. Anal Chem 1993; 65: 1305–1313
Drennen JK, Gebhart BD, Kraimer EG, Lodder RA. Near-infrared spectrometric determination of hydrogen ion, glucose, and human serum albumin in a simulated biological matrix. Spectroscopy 1991; 6: 28–36
Alam MK, Franke JE, Niemczyk TM et al. Near infrared spectroscopy of lysed blood: pH effects. Biomedical Optics'96 Technical Abstract Digest 1996; 113
Hampson NB, Piantadosi CA. Near-infrared optical responses in feline brain and skeletal muscle tissues during respiratory acid-base imbalance. Brain Res 1990; 519: 249–254
Parsons WJ, Rembert JC, Bauman RP, Duhaylongsod FG, Greenfield JC, Piantadosi CA. Myocardial oxygenation in dogs during partial and complete coronary aretery occlusion. Circ Res 1993; 73: 458–464
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Soller, B.R., Micheels, R.H., Coen, J. et al. Feasibility of non-invasive measurement of tissue pH using near-infrared reflectance spectroscopy. J Clin Monitor Comput 12, 387–395 (1996). https://doi.org/10.1007/BF02077636
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DOI: https://doi.org/10.1007/BF02077636