Related Experiment Video
Updated: Apr 23, 2026
Assessment of Respiratory Function in Conscious Mice by Double-chamber Plethysmography
Published on: July 10, 2018
Respiratory inductance plethysmography calibration for pediatric upper airway obstruction: an animal model
Robinder G Khemani1, Rutger Flink2, Justin Hotz3
11] Department of Anesthesiology and Critical Care Medicine, Children's Hospital Los Angeles, Los Angeles, California [2] Department of Pediatrics, University of Southern California Keck School of Medicine, Los Angeles, California.
Background:
We sought to determine optimal methods of respiratory inductance plethysmography (RIP) flow calibration for application to pediatric postextubation upper airway obstruction.
Methods:
We measured RIP, spirometry, and esophageal manometry in spontaneously breathing, intubated Rhesus monkeys with increasing inspiratory resistance. RIP calibration was based on: ΔµV(ao) ≈ M[ΔµV(RC) + K(ΔµV(AB))] where K establishes the relationship between the uncalibrated rib cage (ΔµV(RC)) and abdominal (ΔµV(AB)) RIP signals. We calculated K during (i) isovolume maneuvers during a negative inspiratory force (NIF), (ii) quantitative diagnostic calibration (QDC) during (a) tidal breathing, (b) continuous positive airway pressure (CPAP), and (c) increasing degrees of upper airway obstruction (UAO). We compared the calibrated RIP flow waveform to spirometry quantitatively and qualitatively.
Results:
Isovolume calibrated RIP flow tracings were more accurate (against spirometry) both quantitatively and qualitatively than those from QDC (P < 0.0001), with bigger differences as UAO worsened. Isovolume calibration yielded nearly identical clinical interpretation of inspiratory flow limitation as spirometry.
Conclusion:
In an animal model of pediatric UAO, isovolume calibrated RIP flow tracings are accurate against spirometry. QDC during tidal breathing yields poor RIP flow calibration, particularly as UAO worsens. Routine use of a NIF maneuver before extubation affords the opportunity to use RIP to study postextubation UAO in children.
