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Cardiopulmonary effects of a new inspiratory impedance threshold device in acute hemorrhagic shock in dogs
Author(s) -
Vigani Alessio,
Shih Andre C.,
Buckley Gareth J.,
Londoño Leonel,
Bandt Carsten
Publication year - 2011
Publication title -
journal of veterinary emergency and critical care
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.886
H-Index - 47
eISSN - 1476-4431
pISSN - 1479-3261
DOI - 10.1111/j.1476-4431.2011.00692.x
Subject(s) - medicine , hemorrhagic shock , cardiology , anesthesia , shock (circulatory)
Abstract Objective To compare cardiovascular and respiratory effects of an inspiratory impedance threshold device ( ITD ) in dogs before and after induction of acute hemorrhagic shock. Study Design Prospective experimental randomized study. Animals Eight healthy adult dogs. Methods Dogs were anesthetized and maintained on spontaneous ventilation. Tidal volume (V T ), systolic, mean and diastolic arterial blood pressure ( SAP , MAP , DAP ), central venous pressure ( CVP ), gastric P CO2 ( GBF ) as an indicator of gastric perfusion, cardiac index ( CI ), systemic vascular resistance ( SVR ), oxygen delivery ( DO 2 ), and plasma lactate were monitored. To monitor respiratory compliance ( RC ) and respiratory resistance ( R es R ), animals were briefly placed on mechanical ventilation. Dogs were studied under 4 different conditions: (1) baseline (euvolemic state) ( MAP > 60 mm Hg) with and without the ITD and (2) acute hemorrhagic shock (hypovolemic state) (target MAP of 40 mm Hg) with and without ITD . These 4 conditions were performed during one anesthetic period, allowing time for stabilization of parameters for each condition. Data were analyzed by ANOVA for repeated measure mixed models. Results No cardiovascular changes were detected between groups with and without use of ITD during euvolemic states. During acute hemorrhagic hypovolemic state, CI and DO 2 were higher with the ITD (2.9 ± 0.6 L/min/m 2 ) and (326.5 ± 86.8 mL/min) compared with no ITD (1.8 ± 0.6 L/min/m 2 ) and (191.3 ± 58.1 mL/min), respectively. The use of ITD during hypovolemia also increased SAP and MAP . There was an increase in R es R and decreased RC with the ITD in both euvolemic and hypovolemic states. Conclusion and clinical relevance The use of an ITD in dogs during acute hemorrhagic hypovolemic shock improved cardiovascular parameters but had negative effects on RC and R es R .