Donati PA, Gogniat E, Madorno M, Guevara JM, Guillemi EC, Lavalle MDC, Scorza FP, Mayer GF, Rodriguez PO. Sizing the lung in dogs: the inspiratory capacity defines the tidal volume.
Rev Bras Ter Intensiva 2018;
30:144-152. [PMID:
29995078 PMCID:
PMC6031426 DOI:
10.5935/0103-507x.20180028]
[Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 01/10/2018] [Indexed: 11/20/2022] Open
Abstract
Objective
To evaluate a novel physiological approach for setting the tidal volume in
mechanical ventilation according to inspiratory capacity, and to determine
if it results in an appropriate mechanical and gas exchange measurements in
healthy and critically ill dogs.
Methods
Twenty healthy animals were included in the study to assess the tidal volume
expressed as a percentage of inspiratory capacity. For inspiratory capacity
measurement, the mechanical ventilator was set as follows: pressure control
mode with 35cmH2O of inspired pressure and zero end-expiratory
pressure for 5 seconds. Subsequently, the animals were randomized into four
groups and ventilated with a tidal volume corresponding to the different
percentages of inspiratory capacity. Subsequently, ten critically ill dogs
were studied.
Results
Healthy dogs ventilated with a tidal volume of 17% of the inspiratory
capacity showed normal respiratory mechanics and presented expected
PaCO2 values more frequently than the other groups. The
respiratory system and transpulmonary driving pressure were significantly
higher among the critically ill dogs but below 15 cmH2O in all
cases.
Conclusions
The tidal volume based on the inspiratory capacity of each animal has proven
to be a useful and simple tool when setting ventilator parameters. A similar
approach should also be evaluated in other species, including human beings,
if we consider the potential limitations of tidal volume titration based on
the calculated ideal body weight.
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