Experimental Study On Acute Respiratory Distress Syndrome In Dogs

ObjectiveThe acute lung injury animal model caused by oleic acid in dogs was used to evaluate the feasibility of extravascular lung water (EVLW) as one of the diagnostic criteria to the acute respiratory distress syndrome (ARDS), to analyse the dynamics parameters' role on the diagnosis and treatment of ARDS, and to discuss the therapeutic effect and mechanism of lidocaine to ARDS. We try to provide scientific basis for the diagnosis and treatment of ARDS.MethodsSixteen healthy adult male mongrel dogs weighting 12 to 19 kg were randomly divided into control group (no lidocaine treatment) and test group (with lidocaine treatment). There were eight dogs in each group. All dogs were anesthetized with ketamine (8mg/kg), thiopentone (15mg/kg) and vecuronium (0.12mg/kg). A cuffed endobronchial tube was inserted and artificial respiration with 100% oxygen was provide by a respiratory pump, which respiratory rate was 15 bpm and the tide volume was 15ml/kg. Fentanyl (60μg/kg), vecuronium (0.12mg/kg) and midazolam (0.3mg/kg) were given per hour to maintain anaesthesia. Swan-Ganz catheter, thermal hemodilution catheter and central venous catheter were put respectively. Thirty minutes later, the experiment began and last three hours. The oleic acid (0.10mg/kg) was injected through central vein by microinfusin pump in ten minutes to cause acute lung injury. Lidocaine was given one hour later after the experiment began in test group, whereas the same quantity NS to control group. Arterial blood-gas analysis extra-vascular lung water (EVLW), hemodynamic parameters (PCWP, mPAP, MAP), and inflammatory cytokines (TNF-α, IL-6) were measured every one hour from beginning for 3 hours. Then oxygenation index (01), oxygen delivery (DO₂), oxygen consumption (VO₂), oxygen extraction rate (ERO₂), and...