High frequency mechanical ventilation affects respiratory system mechanics differently in C57BL/6J and BALB/c adult mice

We tested the hypothesis that high frequency ventilation affects respiratory system mechanical functions in C57BL/6J and BALB/c mice. We measured respiratory mechanics by the forced oscillation technique over 1 h in anesthetized, intubated, ventilated BALB/c and C57BL/6J male mice.We did not detect any change in airway resistance, Rn, tissue damping, G, tissue elastance, H and hysteresivity, eta in BALB/c mice during 1 h of ventilation at 150 or at 450 breaths/min; nor did we find a difference between BALB/c mice ventilated at 150 breaths/min compared with 450 breaths/min. Among C57BL/6J mice, except for H, all parameters remained unchanged over 1 h of ventilation in mice ventilated at 150 breaths/min. However, after 10 and 30 min of ventilation at 450 breaths/min, Rn, and respiratory system compliance were lower, and eta was higher, than their starting value. We conclude that high frequency mechanical ventilation affects respiratory system mechanics differently in C57BL/6J and BALB/c adult mice.

► High frequency ventilation affected lung mechanics differently in C57 and BALB mice.
► In BALB, lung mechanics remained unchanged during ventilation at 150 or at 450 breaths/min.
► In C57, after 10 min of ventilation at 450 breaths/min lung mechanics differed from its starting value.
► It is important to determine if the ventilation rate itself alters lung mechanics.