Pulmonary stretch receptor activity during partial liquid ventilation in cats with healthy lungs

Aim: To study whether pulmonary stretch receptor (PSR) activity in
mechanically ventilated young cats with healthy lungs during
partial liquid ventilation (PLV) is different from that during gas
ventilation (GV). Methods: In 10 young cats (4.4 +/- 0.4 months,
2.3 +/- 0.3 kg; mean B SD), PSR instantaneous impulse frequency
(PSR f(imp)) was recorded from single fibres in the vagal nerve
during GV and PLV with perfluorocarbon (30 ml/kg) at increasing
positive inspiratory pressures (PIP; 1.2, 1.8, 2.2 and 2.7 kPa),
and at a positive end-expiratory pressure of 0.5 kPa. Results: All
PSRs studied during GV maintained their phasic character with
increased impulse frequency during inspiration during PLV. Peak PSR
fimp was lower at PIP 1.2 kPa (p < 0.05) and at PIP 2.7 kPa (p =
0.10) during PLV than during GV, giving a lower number of PSR
impulses at these two settings during PLV (p < 0.05).
Conclusion: The phasic character of PSR activity is similar during
GV and PLV. PSR activity is not higher during PLV than during GV in
cats with healthy lungs, indicating no extensive stretching of the
lung during PLV. Copyright (C) 2004 S. Karger AG, Basel.