Objective: To evaluate the use of the caudal vena cava collapsibility index (CVCCI) as a predictor of fluid responsiveness in hospitalized, critically ill dogs with hemodynamic or tissue perfusion abnormalities.

Serial US and CT help guide treatment for stable patients with penetrating stab injuries to the abdomen.

ObjectiveTo 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.MethodsTwenty 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.ResultsHealthy 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.ConclusionsThe 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.

Case summary A 9-year-old neutered male domestic shorthair cat was presented for evaluation of severe hemodynamic collapse and suspected lower urinary tract disease. On admission, severe metabolic acidosis, hyperkalemia and azotemia, and electrocardiographic findings consistent with cardiotoxicity were identified. The diagnosis of uroabdomen was made based on abdominal fluid to plasma concentration ratios of creatinine and potassium. A central line catheter was placed percutaneously into the abdomen for peritoneal drainage and used for peritoneal dialysis as a bridge to surgery. Retrograde contrast cystography confirmed rupture of the urinary bladder. Point-of-care ultrasound of the chest postoperatively revealed the presence of mild pleural effusion. Echocardiography was then performed showing no evidence of cardiac disease. Pleural fluid analysis revealed a transudate with a creatinine ratio of 2.38 ([Creatinine]pleural fluid/[Creatinine]plasma), consistent with the diagnosis of urothorax. The cat recovered uneventfully from surgery and was monitored for signs of respiratory distress during the rest of its stay in hospital. The cat was discharged 4 days later and the pleural effusion resolved without further medical intervention. Relevance and novel information There is limited information on the causes of urothorax and uroabdomen management of feline patients. Pleural effusion is a complication observed in critically ill cats secondary to fluid overload, underlying cardiomyopathy, primary thoracic pathology or a combination of these. To our knowledge, this is the first report of urothorax in a cat secondary to non-traumatic uroabdomen. Careful monitoring of respiratory signs consistent with pleural space disease is recommended in cases of uroabdomen.

Objective To evaluate the accuracy of selected echocardiographic variables used to predict fluid responsiveness in hospitalized dogs with compromised hemodynamics and tissue hypoperfusion. Design Diagnostic test study in a prospective cohort of hospitalized dogs. Setting Veterinary referral clinics. Animals Forty‐four hospitalized dogs with compromised hemodynamics and tissue hypoperfusion were utilized in this study. Interventions Echocardiographic examination before and after fluid replacement with 30 ml/kg of lactated Ringer's solution. Measurements and Main Results Pre‐fluid replacement measurements of velocity of transmitral E wave (E‐peak), the left ventricular end‐diastolic internal diameter normalized to body weight (LVIDdN), and the left ventricular end‐systolic internal diameter normalized to body weight (LVIDsN) were significantly lower in fluid‐responsive patients compared with nonresponders (P < 0.001). The area under the receiver operating characteristic curve (AUROC) with its 95% confidence interval (CI) for each significant predictor was as follows: E‐peak 0.907 (0.776–1.000, P < 0.001) and LVIDdN 0.919 (0.801–1.000, P < 0.001). The predictive capacity of LVIDsN was not significantly better than chance (AUROC, 0.753; 95% CI, 0.472–1.000, P = 0.078). A significant negative linear correlation was observed between the percentage of increase in velocity–time integral after expansion and the echocardiographic variables LVIDdN (rs = –0.452, P = 0.023) and E‐peak (rs = –0.396, P = 0.008) pre‐fluid replacement. The intraobserver and interobserver variability was very low (<5 %) for all measurements. Conclusions In this study using critically ill dogs with compromised hemodynamics and tissue hypoperfusion, pre‐fluid replacement measurements of LVIDdN and E‐peak adequately predict fluid responsiveness. Because a small number of fluid nonresponders were involved in the present study (11.4%), further studies that include larger numbers of fluid‐nonresponsive animals are required.