Evaluation of three tidal volumes (10, 12 and 15 mL kg^-1) in dogs for controlled mechanical ventilation assessed by volumetric capnography: a randomized clinical trial

Publikationen als Autor:in / Herausgeber:in der Vetmeduni

Schramel, Johannes

Abstrakt

Objective To evaluate three routinely used tidal volumes (V-T; 10, 12 and 15 mL kg(-1)) for controlled mechanical ventilation (CMV) in lung healthy anaesthetized dogs by assessing alveolar ventilation (VTalv) and dead space (DS). Study design Prospective, randomized clinical trial. Animals A total of 36 client-owned dogs. Methods Dogs were randomly allocated to a VT of 10 (G(10)), 12 (G(12)) or 15 (G(15)) mL kg(-1). After induction CMV was started. End-tidal carbon dioxide tension was maintained at 4.7-5.3 kPa by changing the respiratory frequency (f(R); 6 < f(R) < 30 breaths minute(-1)). After 29 minutes, cardiovascular and respiratory variables were recorded for 3 minutes using a multiparameter monitor, volumetric capnography (VCap) and a blood gas analyser. The ratios of VTalv to body weight (VTalv kg(-1)) and airway DS to VT (VDaw/V-T), Bohr's DS (VDBohr), Enghoffs DS (VDBE) and the volume of expired carbon dioxide per breath (VTCO2,br) were calculated. Mean airway pressure (MawP), f(R) and peak inspiratory pressure (PIP) were recorded. Data were analysed using one-way ANOVA and Student-Newman-Keuls tests with a statistical significance set at p < 0.05. Results No differences were observed for demographic data and cardiovascular variables between groups. A total of three dogs were excluded because of technical difficulties and one because of fR > 30. VTalv kg(-1) (p = 0.001) increased and VDBohr (p = 0.002) decreased with greater V-T. VTCO2,br (p = 0.017) increased and VDaw/V-T (p = 0.006), VDBE (p = 0.008) and f(R) (p = 0.002) decreased between G(10) and G(15). PIP (p = 0.013) was significantly higher in G(15) compared with that in G(10) and G(12). No changes were observed in MawP. Conclusions and clinical relevance A V-T of 15 mL kg(-1) is most appropriate for CMV in lung healthy dogs (as evaluated by respiratory mechanics and VCap) and does not impair cardiovascular variables.

Dokumententyp

Originalarbeit

DOI

10.1016/j.vaa.2016.10.007

PubMed ID

MEDLINE:28807576