Effects of pressure- and volume-controlled ventilation on the work of breathing in cats using a cuffed endotracheal tube

Abstract

Background and Aim: Mechanical ventilation is essential for supporting patients' respiratory function when they are under general anesthesia. For cats with limited lung capacity, the different effects of volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) on respiratory function remain elusive. The objective of the present study was to compare the efficacy of VCV and PCV in cats under general anesthesia using a cuffed endotracheal tube (ETT). Materials and Methods: Twelve healthy cats were randomly allocated to either a VCV or PCV group. Five tidal volumes (6, 8, 10, 12, and 14 mL/kg) were randomly applied to assess the efficacy of VCV, and respiratory rates were adjusted to achieve a minute ventilation of 100 mL/kg/min. Peak inspiratory pressures (4, 5, 6, 7, and 8 mmHg) were randomly applied to assess the efficacy of PCV, and respiratory rates were adjusted to achieve a minute ventilation of 100 mL/kg/min. Blood pressure, gas leakages, and end-tidal CO2 were recorded from 60 trials for airway control during the use of VCV or PCV. Data were compared using Fisher's exact test with a significance level of p<0.05. Results: Leakages did not differ between VCV (1/60 events) and PCV (0/60 events; p=0.500). Hypercapnia was identified when using VCV (6/60 events) less frequently than when using PCV (7/60 events; p=0.762), but did not reach statistical significance. Hypotension (mean arterial blood pressure <60 mmHg) occurred less frequently with VCV (0/60 events) than with PCV (9/60 events; p=0.003). Moreover, VCV provided a significantly lower work of breathing (151.10±65.40 cmH2O mL) compared with PCV (187.84±89.72 cmH2O mL; p<0.05). Conclusion: VCV in cats using a cuffed ETT causes less hypotension than PCV. It should be noted that VCV provides a more stable tidal volume compared with PCV, resulting in a more stable minute volume. Nonetheless, VCV should not be used in patients with an airway obstruction because higher peak airway pressure may occur and lead to lung injury.

Comparative study of ventilation techniques with supraglottic airway devices in cats: volume-controlled vs pressure-controlled techniques

“…This finding is in line with our previous study using an ETT. 39 Chronic use of a ventilator is associated with increased WOB and may lead to respiratory failure in humans. It is helpful to use a ventilator mode with a lower WOB for prolonged use of a ventilator in unconscious patients or those in the intensive care unit.…”

PCV‐VG combined individualized PEEP determination in one‐lung ventilated patients with PEEP step change direction: A randomized controlled trial

“…VCV, a ventilation model commonly used in clinical practice, ensures stable ventilation but generates high airway pressures, which in turn generates volume injury and leads to uneven gas distribution in the lungs 15 . PCV reduces airway pressure and decelerates airflow, but may cause lung injury by exerting traction on the alveoli 16 .…”

“…VCV, a ventilation model commonly used in clinical practice, ensures stable ventilation but generates high airway pressures, which in turn generates volume injury and leads to uneven gas distribution in the lungs. 15 PCV reduces airway pressure and decelerates airflow, but may cause lung injury by exerting traction on the alveoli. 16 However, PCV‐VG combines the advantages of VCV and PCV, which allows the use of decelerated airflow in the volume‐controlled mode and simultaneously ensures V T airflow declaration, reducing airway and alveolar damage from high airway pressures, and protecting the lungs in various fields.…”