John Griffith Toffaletti

John Griffith Toffaletti
Professor in Pathology

Research Abstract

Use of lactate measurements as indicator of inadequate oxygen utilization and/or mitochondrial dysfunction in critical care. Blood lactate measurements are correlated to clinical progress of patients with sepsis, during and after surgery, during ECMO, and for triage use in the Emergency Department.

Effects of changes in ionized calcium and magnesium on concentrations of parathyroid hormone (PTH) in blood. Normal blood donors are given an infusion of a physiologic solution after donating blood, which should alter free calcium and/or magnesium to help determine the relative effects of calcium and magnesium on PTH secretion.

The changes and variation over time of serum creatinine, cystatin C, eGFR, and GFR measurements in healthy persons and how this relates to diagnosing changes in renal function.

Effects of albumin and other colloids on hematocrit measured by impedence. Blood from patients on cardiopulmonary bypass often shows lower hematocrit results by impedence compared to centrifugation. We have examined the effects of albumin and Hespan (Hetastarch) on impedence-measured hematocrit on different analyzers.

The effects on pO2 of transport by pneumatic tube. Increases in pO2 have been noted if blood contains even tiny air bubbles in the syringe when sent by pneumatic transport.

Current Appointments & Affiliations

Professor in Pathology, Pathology, Clinical Science Departments 2006

Contact Information

Duhs Central Automated Lab Rm, Durham, NC 27705
Duke Box 3015, Durham, NC 27710
john.toffaletti@duke.edu (919) 684-4754

Background
Education, Training, & Certifications
- Assistant Professor of Pathology, Pathology, Duke University 1979 - 1986
- Postdoctoral Fellow, Clinical Chemistry, University of North Carolina at Chapel Hill 1977 - 1979
- Ph.D., University of North Carolina at Chapel Hill 1977
- B.S., University of Florida 1972
Duke Appointment History
- Associate Professor of Pathology, Pathology, Clinical Science Departments 1989 - 2005
Research
Selected Grants
- GEM® Premier¿ 5000 Critical Care System Pleural Fluid pH External Method Comparison Protoco awarded by Instrumentation Laboratory Company 2018 - 2019
- EDAN i15 Compartive Method Study awarded by EDAN Diagnostics, Inc 2016 - 2017
- GLUCOSE Monitor Meter with the GLUCOSE Monitor Test Strip High Altitude awarded by Roche Laboratories, Inc. 2014 - 2015
- GLUCOSE Monitor Meter with the GLUCOSE Monitor Test Strip Hyperbaric Chamber Evaluation awarded by Roche Laboratories, Inc. 2014 - 2015
- GEM Premier 5000 Pre-Beta 2 External Evaluation awarded by Instrumentation Laboratory 2014 - 2015
- GEM Premier 5000 IUO awarded by Instrumentation Laboratory 2013 - 2014
Publications & Artistic Works
Selected Publications
- Academic Articles
  - Toffaletti, JG, Hammett-Stabler, C, and Handel, EA. "Effect of beef ingestion by humans on plasma concentrations of creatinine, urea, and cystatin C." Clinical Biochemistry 58 (August 2018): 26-31. Full Text
  - Rosenbaum, MW, Flood, JG, Melanson, SEF, Baumann, NA, Marzinke, MA, Rai, AJ, Hayden, J, Wu, AHB, Ladror, M, Lifshitz, MS, Scott, MG, Peck-Palmer, OM, Bowen, R, Babic, N, Sobhani, K, Giacherio, D, Bocsi, GT, Herman, DS, Wang, P, Toffaletti, J, Handel, E, Kelly, KA, Albeiroti, S, Wang, S, Zimmer, M, Driver, B, Yi, X, Wilburn, C, and Lewandrowski, KB. "Quality Control Practices for Chemistry and Immunochemistry in a Cohort of 21 Large Academic Medical Centers." American Journal of Clinical Pathology 150, no. 2 (July 2018): 96-104. Full Text
  - Toffaletti, JG, Hammett-Stabler, CA, Gearhart, M, Roy Choudhury, K, and Handel, EA. "The analytical change in plasma creatinine that constitutes a biologic/physiologic change." Clinica chimica acta; international journal of clinical chemistry 459 (August 2016): 79-83. Full Text
  - Toffaletti, JG, and Rackley, CR. "Monitoring Oxygen Status." Advances in clinical chemistry 77 (January 2016): 103-124. (Review) Full Text
  - Louie, RF, Curtis, CM, Toffaletti, JG, Handel, EA, Slingerland, RJ, Fokkert, MJ, Muller, W, Weinert, SE, Lee, DM, and Kotagiri, S. "Performance Evaluation of a Glucose Monitoring System for Point-of-Care Testing With the Critically Ill Patient Population—A Multicenter Study." Point of Care: The Journal of Near-Patient Testing & Technology 14, no. 1 (March 2015): 37-41. Full Text
  - Brazg, R, Hughes, K, Martin, P, Coard, J, Toffaletti, J, McDonnell, E, Taylor, E, Farrell, L, Patel, M, Ward, J, Chen, T, Alva, S, and Ng, R. "Clinical evaluation of the freestyle precision pro system." Clinica Chimica Acta 421 (2013): 243-250. Full Text
  - Toffaletti, JG. "Clarifying the fog of natural and manmade renal function tests: Creatinine, clearances, glomerular filtration rate, and estimated glomerular filtration rate." Point of Care 10, no. 1 (2011): 45-50. Full Text
  - Toffaletti, JG. "Improving the clinical value of estimating glomerular filtration rate by reporting all values: a contrarian viewpoint." Nephron Clin Pract 115, no. 3 (2010): c177-c181. (Review) Full Text Link to Item
  - Toffaletti, JG, and McDonnell, EH. "Variation of serum creatinine, cystatin C, and creatinine clearance tests in persons with normal renal function." Clinica Chimica Acta; International Journal of Clinical Chemistry 395, no. 1-2 (September 2008): 115-119. Full Text
  - Toffaletti, JG, McDonnell, EH, Ramanathan, LV, Tolnai, J, Templin, R, and Pompa, L. "Validation of a quality assessment system for blood gas and electrolyte testing." Clin Chim Acta 382, no. 1-2 (July 2007): 65-70. Full Text Link to Item
  - Toffaletti, J, and Zijlstra, WG. "Misconceptions in reporting oxygen saturation." Anesthesia and Analgesia 105, no. SUPPL. 6 (2007): S5-S9. Full Text
  - Toffaletti, JG. "Controlling magnesium in surgery, intensive care, and beyond." Point of Care 6, no. 2 (2007): 129-133. Full Text
  - Patteril, M, Stafford-Smith, M, Toffaletti, JG, Bute, BP, Milano, CA, and Welsby, IJ. "Changing systems for measuring activated clotting times: impact on the clinical practice of heparin anticoagulation during cardiac surgery." Clin Chim Acta 356, no. 1-2 (June 2005): 218-224. Full Text Link to Item
  - Lanzinger, MJ, Moretti, EW, Wilderman, RF, El-Moalem, HE, Toffaletti, JG, and Moon, RE. "The relationship between ionized and total serum magnesium concentrations during abdominal surgery." Journal of Clinical Anesthesia 15, no. 4 (June 2003): 245-249. Full Text
  - Boldt, J, Goerlach-Graw, A, Halwachs-Baumann, G, Hindinger, J, Leinberger, R, Luebke, B, Nagel, D, Normand, H, Quintel, M, Riegebauer, J, Semmelrock, HJ, Toffaletti, J, and Zerback, R. "Multicenter Study on the Analytical Performance of a New Point-of-Care Blood Gas Analyzer." Plastic Surgical Nursing 2, no. 3 (January 1, 2003): 214-219.
  - Toffaletti, JG, McDonnell, EH, Welsby, I, Shearer, IR, Sketch, MH, and Tcheng, JE. "Implementing a New Method for Activated Clotting Time." Plastic Surgical Nursing 2, no. 2 (January 1, 2003): 125-128.
  - Wang, S, McDonnell, EH, Sedor, FA, and Toffaletti, JG. "pH effects on measurements of ionized calcium and ionized magnesium in blood." Arch Pathol Lab Med 126, no. 8 (August 2002): 947-950. Full Text Link to Item
  - Welsby, IJ, McDonnell, E, El-Moalem, H, Stafford-Smith, M, and Toffaletti, JG. "Activated clotting time systems vary in precision and bias and are not interchangeable when following heparin management protocols during cardiopulmonary bypass." J Clin Monit Comput 17, no. 5 (July 2002): 287-292. Link to Item
  - Vote, DA, Doar, O, Moon, RE, and Toffaletti, JG. "Blood glucose meter performance under hyperbaric oxygen conditions." Clin Chim Acta 305, no. 1-2 (March 2001): 81-87. Link to Item
  - Toffaletti, JG, and Wildermann, RF. "The effects of heparin anticoagulants and fill volume in blood gas syringes on ionized calcium and magnesium measurements." Clin Chim Acta 304, no. 1-2 (February 2001): 147-151. Link to Item
  - Toffaletti, J. "Wireless POCT data transmission." MLO: medical laboratory observer 32, no. 6 (2000): 44-50.
  - Toffaletti, JG, and Wildermann, RF. "Use of turbidity-correction algorithm eliminates the effect of perflubron emulsion on CO-oximeter results." Clin Chem 46, no. 1 (January 2000): 136-137. (Letter) Link to Item
  - Vote, DA, Doar, PO, Moon, RE, and Toffaletti, JG. "Measurement of plasma glucose under hyperbaric oxygen conditions." South Pacific Underwater Medicine Society Journal 30, no. 4 (2000): 182-186.
  - Toffaletti, J. "Blood gas testing in the laboratory and at the point of care. Finding the right mix." MLO: medical laboratory observer Suppl (1997): 14-17.
  - Astles, JR, Lubarsky, D, Loun, B, Sedor, FA, and Toffaletti, JG. "Pneumatic transport exacerbates interference of room air contamination in blood gas samples." Archives of Pathology & Laboratory Medicine 120, no. 7 (July 1996): 642-647.
  - Astles, JR, Sedor, FA, and Toffaletti, JG. "Evaluation of the YSI 2300 glucose analyzer: algorithm-corrected results are accurate and specific." Clin Biochem 29, no. 1 (February 1996): 27-31. Link to Item
  - Toffaletti, J. "Elevations in blood lactate: Overview of use in critical care." Scandinavian Journal of Clinical and Laboratory Investigation, Supplement 56, no. 224 (1996): 107-110.
  - Toffaletti, J, and Hansell, D. "Interpretation of blood lactate measurements in paediatric open-heart surgery and in extracorporeal membrane oxygenation." Scandinavian Journal of Clinical and Laboratory Investigation 55, no. 4 (1995): 301-307.
  - Toffaletti, J, and Thompson, T. "Effects of blended lithium-zinc heparin on ionized calcium and general clinical chemistry tests." Clinical Chemistry 41, no. 2 (1995): 328-329.
  - Toffaletti, J. "Physiology and regulation: Ionized calcium, magnesium and lactate measurements in critical care settings." American Journal of Clinical Pathology 104, no. 4 SUPPL. 1 (1995): S88-S94.
  - Toffaletti, J. "Use of novel preparations of heparin to eliminate interference in ionized calcium measurements: Have all the problems been solved?." Clinical Chemistry 40, no. 4 (1994): 508-509.
  - Paschen, K, Hagemann, P, Lang, HR, Cortes, M, Weidemann, G, Toffaletti, J, Burritt, M, Leinberger, R, Tritschler, W, and Ramstetter, E. "Determination of potassium by dry reagent carrier technology: a multicentre evaluation." European journal of clinical chemistry and clinical biochemistry : journal of the Forum of European Clinical Chemistry Societies 31, no. 8 (August 1993): 545-552.
  - Paschen, K, Hagemann, P, Lang, HRM, Cortes, M, Weidemann, G, Toffaletti, J, Burritt, M, Leinberger, R, Tritschler, W, Ramstetter, E, and Vogel, P. "Determination of potassium by dry reagent carrier technology: A multicentre evaluation." European Journal of Clinical Chemistry and Clinical Biochemistry 31, no. 8 (1993): 545-552.
  - Toffaletti, J, Hammes, ME, Gray, R, Lineberry, B, and Abrams, B. "Lactate measured in diluted and undiluted whole blood and plasma: Comparison of methods and effect of hematocrit." Clinical Chemistry 38, no. 12 (1992): 2430-2434.
  - Toffaletti, J, Cooper, DL, and Lobaugh, B. "The response of parathyroid hormone to specific changes in either ionized calcium, ionized magnesium, or protein-bound calcium in humans." Metabolism 40, no. 8 (August 1991): 814-818. Link to Item
  - Anderson, DJ, Lente, FV, Apple, FS, Kazmierczak, SC, Lott, JA, Gupta, MK, McBride, N, Katzin, WE, Scott, RE, Toffaletti, J, Menendez-Botet, CJ, Schwartz, MK, Castellani, WJ, Hage, DS, Allen, RC, Griffiths, JC, Hepler, BR, Touchstone, JC, Skogerboe, KJ, Wang, J, Kuesel, AC, Kroft, T, Smith, ICP, Haas, RG, and Chou, D. "Clinical chemistry." Analytical Chemistry 63, no. 12 (1991): 165R-270R.
  - Toffaletti, J, Ernst, P, Hunt, P, and Abrams, B. "Dry electrolyte-balanced heparinized syringes evaluated for determining ionized calcium and other electrolytes in whole blood." Clinical Chemistry 37, no. 10 (1991): 1730-1733.
  - Toffaletti, JG. "Blood lactate: biochemistry, laboratory methods, and clinical interpretation." Crit Rev Clin Lab Sci 28, no. 4 (1991): 253-268. (Review) Full Text Link to Item
  - Christenson, RH, Clemmensen, P, Ohman, EM, Toffaletti, J, Silverman, LM, Grande, P, Vollmer, RT, and Wagner, GS. "Relative increase in creatine kinase MB isoenzyme during reperfusion after myocardial infarction is method dependent." Clinical Chemistry 36, no. 8 (1990): 1444-1449.
  - Christenson, RH, Ohman, EM, Clemmensen, P, Grande, P, Toffaletti, J, Silverman, LM, Vollmer, RT, and Wagner, GS. "Characteristics of creatine kinase-MB and MB isoforms in serum after reperfusion in acute myocardial infarction." Clin Chem 35, no. 11 (November 1989): 2179-2185. Link to Item
  - Bode, AP, Miller, DT, and Toffaletti, J. "Plasma levels of ionized and total calcium during storage of citrated platelet concentrate." Transfusion 29, no. 6 (1989): 534-538.
  - Toffaletti, J, and Abrams, B. "Effects of in vivo and in vitro production of lactic acid on ionized, protein-bound, and complex-bound calcium in blood." Clinical Chemistry 35, no. 6 (1989): 935-938.
  - Toffaletti, J, Abrams, B, Bird, C, and Schwing, M. "Clinical validation of an automated thin-film reflectance method for measurement of magnesium in serum and urine." Magnesium 7, no. 2 (1988): 84-90.
  - Toffaletti, J, Bird, C, Berg, C, and Abrams, B. "Aqueous and serum-based materials compared for use as simulated calibrators for three ionized calcium analyzers." Clinical Chemistry 32, no. 8 (1986): 1548-1550.
  - Toffaletti, J, Christenson, RH, Mullins, S, and Harris, RE. "Relationship between serum lactate and ionized calcium in open-heart surgery." Clinical Chemistry 32, no. 10 (1986): 1849-1853.
  - Toffaletti, J. "Chemistry analyzers for the physician's office." Pathologist 40, no. 5 (1986): 25-33.
  - Toffaletti, J, Nissenson, R, Endres, D, McGarry, E, and Mogollon, G. "Influence of continuous infusion of citrate on responses of immunoreactive parathyroid hormone, calcium and magnesium components, and other electrolytes in normal adults during plateletapheresis." Journal of Clinical Endocrinology and Metabolism 60, no. 5 (1985): 874-879.
  - Toffaletti, J, and Lee, KM. "Preparation and use of serum-based material as control and calibrator in evaluating ion-selective electrodes for calcium." Clinical Chemistry 31, no. 8 (1985): 1349-1352.
  - Toffaletti, J. "Analytical aspects and clinical applications of ionized calcium measurements." Health Care Instrumentation 1, no. 2 (1985): 66-73.
  - Toffaletti, J. "Automated dry-film method for phosphorus in serum evaluated." Clinical Chemistry 31, no. 1 (1985): 148-149.
  - Toffaletti, J, Blosser, N, and Kirvan, K. "Effects of storage temperature and time before centrifugation on ionized calcium in blood collected in plain vacutainer tubes and silicone-separator (SST) tubes." Clinical Chemistry 30, no. 4 (1984): 553-556.
  - Toffaletti, J, Blosser, N, Hall, T, Smith, S, and Tompkins, D. "An automated dry-slide enzymatic method evaluated for measurement of creatinine in serum." Clinical Chemistry 29, no. 4 (1983): 684-687.
  - Toffaletti, J. "Changes in protein-bound, complex-bound, and ionized calcium related to parathyroid hormone levels in healthy donors during plateletapheresis." Transfusion 23, no. 6 (1983): 471-475.
  - Toffaletti, J. "Total, ultrafiltrable, dialysable and ionised calcium measurements in randomly selected samples compared with clinical diagnoses." Annals of Clinical Biochemistry 20, no. 6 (1983): 349-352.
  - Toffaletti, J, Holleman, C, and Bournique, J. "Interference in the Dow phosphorus procedure eliminated by ultrafiltration of icteric and hemolyzed samples with the Worthington Ultrafree Calcium Filter." Clinical Chemistry 28, no. 3 (1982): 560--.
  - Toffaletti, J, and Hemker, J. "Dialyzable calcium measured in 60 micro L of routinely processed serum by continuous-flow analysis with CO2/air segmentation." Clinical Chemistry 28, no. 8 (1982): 1815-1816.
  - Tompkins, D, and Toffaletti, J. "Enzymic determination of citrate in serum and urine, with use of the Worthington 'Ultrafree' device." Clinical Chemistry 28, no. 1 (1982): 192-195.
  - Toffaletti, J, Tompkins, D, and Hoff, G. "The Worthington 'Ultrafree' device evaluated for determination of ultrafiltrable calcium in serum." Clinical Chemistry 27, no. 3 (1981): 466-468.
  - Toffaletti, J, and Kirvan, K. "Spectrophotometric micro method for measurement of dialyzable calcium by use of cresolphthalein complexone and continuous-flow analysis." Clinical Chemistry 26, no. 11 (1980): 1562-1565.
  - Toffaletti, J, McComb, RB, and Jr, GNB. "Increase in dialyzable calcium associated with therapy with lithium." Clinical Chemistry 25, no. 10 (1979): 1806-1809.
  - Toffaletti, J, McComb, RB, and Jr, GNB. "Higher incidence of hypercalcemia in patients receiving lithium therapy as determined by measurements of dialyzable and total calcium in serum." Clinical Chemistry 25, no. 6 (1979): No.-388.
  - Toffaletti, J, and Jr, GNB. "The possible physiologic importance of calcium complexes: An opinion." Clinica Chimica Acta 97, no. 2-3 (1979): 101-105.
  - Toffaletti, J, and Jr, GNB. "Improvements in and clinical utility of a continuous-flow method for routine measurement of dialyzable (ultrafiltrable) calcium." Clinical Chemistry 25, no. 11 (1979): 1939-1943.
  - Toffaletti, J, Savory, J, and Gitelman, HJ. "Continuous flow determination of dialyzable calcium in serum." Clinical Chemistry 23, no. 7 (1977): 1258-1263.
  - Toffaletti, J, Savory, J, and Gitelman, HJ. "Use of gel filtration to examine the distribution of calcium among serum proteins." Clinical Chemistry 23, no. 12 (1977): 2306-2310.
  - Peron, LC, and Toffaletti, JG. "Concentration of lead in various endodontic filling materials." J Endod 2, no. 1 (January 1976): 21-24. Full Text Link to Item
  - Toffaletti, J, Gitelman, HJ, and Savory, J. "Separation and quantitation of serum constituents associated with calcium by gel filtration." Clinical Chemistry 22, no. 12 (1976): 1968-1972.
  - Toffaletti, J, and Savory, J. "An overview of the laboratory diagnosis of lead poisoning." Annals of Clinical and Laboratory Science 6, no. 6 (1976): 529-536.
  - Toffaletti, J, and Savory, J. "Use of sodium borohydride for determination of total mercury in urine by atomic absorption spectrometry." Analytical Chemistry 47, no. 13 (1975): 2091-2095. Full Text

Some information on this profile has been compiled automatically from Duke databases and external sources. (Our About page explains how this works.) If you see a problem with the information, please write to Scholars@Duke and let us know. We will reply promptly.

Education, Training, & Certifications

Duke Appointment History

Selected Grants

Selected Publications

Academic Articles