Newly Published
Perioperative Medicine  |   September 2018
Ultrasound Elastography for Rapid, Real-time Detection of Localized Muscular Reaction in Malignant Hyperthermia–susceptible Pigs
Author Notes
  • From the Department of Anaesthesia and Critical Care, University of Wuerzburg, Wuerzburg, Germany.
  • Submitted for publication January 19, 2018. Accepted for publication August 1, 2018.
    Submitted for publication January 19, 2018. Accepted for publication August 1, 2018.×
  • Part of the work presented in this article has been presented as an abstract at the Scientific Days (WAT) of the German Society of Anesthesiology and Intensive Care Medicine in Wuerzburg, Germany, February 24 and 25, 2017, and at the Annual Meeting of the European Malignant Hyperthermia Group in Antwerp, Belgium, June 1 and 2, 2017.
    Part of the work presented in this article has been presented as an abstract at the Scientific Days (WAT) of the German Society of Anesthesiology and Intensive Care Medicine in Wuerzburg, Germany, February 24 and 25, 2017, and at the Annual Meeting of the European Malignant Hyperthermia Group in Antwerp, Belgium, June 1 and 2, 2017.×
  • Acknowledgments: The authors thank Judith Skirde, chief technician, Center for Malignant Hyperthermia, University of Wuerzburg, Wuerzburg, Germany, for essential advice and technical assistance with this study.
    Acknowledgments: The authors thank Judith Skirde, chief technician, Center for Malignant Hyperthermia, University of Wuerzburg, Wuerzburg, Germany, for essential advice and technical assistance with this study.×
  • Research Support: Support was provided solely from institutional and/or departmental sources.
    Research Support: Support was provided solely from institutional and/or departmental sources.×
  • Competing Interests: The authors declare no competing interests.
    Competing Interests: The authors declare no competing interests.×
  • Correspondence: Address correspondence to Dr. Johannsen: Department of Anaesthesia and Critical Care, University of Wuerzburg, Oberduerrbacher Strasse 6, 97080 Wuerzburg, Germany. johannsen_s@ukw.de. Information on purchasing reprints may be found at www.anesthesiology.org or on the masthead page at the beginning of this issue. Anesthesiology’s articles are made freely accessible to all readers, for personal use only, 6 months from the cover date of the issue.
Article Information
Perioperative Medicine / Patient Safety / Radiological and Other Imaging
Perioperative Medicine   |   September 2018
Ultrasound Elastography for Rapid, Real-time Detection of Localized Muscular Reaction in Malignant Hyperthermia–susceptible Pigs
Anesthesiology Newly Published on September 10, 2018. doi:10.1097/ALN.0000000000002424
Anesthesiology Newly Published on September 10, 2018. doi:10.1097/ALN.0000000000002424
Abstract

Editor’s Perspective:

What We Already Know about This Topic:

  • Awareness of a patient’s malignant hyperthermia predis position based on diagnostic testing is essential to preventing serious malignant hyperthermia events

  • The in vitro contracture test after surgical muscle biopsy is a well-established and comprehensive diagnostic test

  • Genetic testing can be used to confirm malignant hyper thermia susceptibility but not to exclude it

What This Article Tells Us That Is New:

  • In vivo ultrasound (shear-wave) elastography detected a temporary increase in local tissue stiffness soon after intramuscular injection of halothane and caffeine in malignant hyperthermia–susceptible pigs

  • Quantitative shear-wave elastography allowed earlier detection of reactions to halothane and caffeine than did measurement of local lactate concentrations in microdialysis fluids, although the responses were analogous

Background: Halothane and caffeine induce excessive sarcoplasmic calcium liberation and skeletal muscle contracture in patients susceptible to malignant hyperthermia (MH) and are utilized for diagnosis in the in vitro contracture test. Intramuscular injection previously caused a marked local lactate increase in MH-susceptible but not in MH-nonsusceptible individuals in vivo. Using shear-wave elastography, this study evaluated localized changes in muscle stiffness after intramuscular injection of halothane and caffeine.

Methods: Microdialysis probes were placed into the gracilis muscle of 16 pigs (9 MH-susceptible and 7 MH-nonsusceptible). After local injection of either halothane or caffeine in different concentrations, changes of tissue elasticity surrounding the probe were examined by quantitative shear-wave elastography. Local lactate concentrations were analyzed spectrophotometrically.

Results: Ultrasound elastography detected a temporary increase in local muscle rigidity in MH-susceptible but not in MH-nonsusceptible pigs after 2.5 and 5 vol% halothane and after 10, 40, and 80 mM caffeine, whereas there were no differences in the control groups (median [interquartile range] for maximum effect after 5 vol% halothane: MH-susceptible: 97 [31 to 148] vs. MH-nonsusceptible: 5 [−6 to 18] kPa; P = 0.0006; maximum effect after 80 mM caffeine: 112 [64 to 174] vs. −3 [−6 to 35] kPa; P = 0.0002). These effects were seen rapidly within 5 min. Local lactate concentrations were higher in MH-susceptible versus nonsusceptible pigs after 1 and 2.5 vol% halothane and 10, 40, and 80 mM caffeine (2.5 vol% halothane: MH-susceptible: 2.8 [1.9 to 4.4] vs. MH-nonsusceptible: 0.6 [0.6 to 0.7] mmol/l; P < 0.0001; 80 mM caffeine: 5.2 [4.1 to 6.3] vs. 1.6 [1.2 to 2.4] mmol/l; P < 0.0001). After 10 vol% halothane, rigidity and lactate levels were increased in both MH-susceptible and MH-nonsusceptible animals.

Conclusions: This pilot study revealed shear-wave elastography as a suitable technique for real-time detection of altered tissue elasticity in response to pharmacologic stimulation. By considering the variability of these results, further test protocol optimization is required before elastography could serve as a minimally invasive MH diagnostic test.