Fig. 8

Biomarkers to translate the laryngospasm evidence in our rat model to human subjects. Taken from [103, 104] with permission. A critical of finding during simulated laryngospasm was thoracic EMG bursts associated with attempts to inspire against the closed airway could be easily seen in ECG and even EEG records, especially when high-pass filtered (a). The presence of this extra effort clearly heralded the obstructive apnea period and steadily increased until stopping completely (a, b), which was the point of respiratory arrest. A second biomarker is also available, particularly late during the period of airway obstruction. This second biomarker is the development of significant RR interval variability due to both the bradycardia and conduction block as well as the development of very short intervals (c–e). EMG electromyogram, RR interval time interval between successive R-wave peaks in the PQRST sequence of each heart beat, SDNN standard deviation of the mean interval between successive R-waves in an ECG recording, PIP peak inspiratory pressure developed inside the closed respiratory system by inspiratory effort against the closed airway