Transfusion therapy in emergency and critical care medicine

Development of a severity scoring system for acute haemorrhage in anaesthetized domestic cats: the CABSS score

OBJECTIVE

To determine whether physiological, haematological, biochemical or electrolyte variables can predict severe haemorrhage in cats.

STUDY DESIGN

Randomized crossover study whereby each cat underwent mild and severe haemorrhage, with a 2 month period between events.

ANIMALS

A group of six domestic cats aged 21 ± 1 months and weighing 4.9 ± 1.2 kg, mean ± standard deviation.

METHODS

Cats were anaesthetized (buprenorphine, alfaxalone, isoflurane in oxygen at a fixed end-tidal concentration of 1.7%) before the haemorrhage event. In total, 34 variables were measured twice (prehaemorrhage and posthaemorrhage). The difference and percent change for each variable were compared between haemorrhage events (paired t test). Significant variables were placed into 13 different ratios (posthaemorrhage value of one variable divided by a posthaemorrhage value of a second variable) and compared (paired t test), and Cohen's d (d) was calculated. Receiver operating characteristic curves were plotted and cut-off values for weak, moderate and strong indicators of severe haemorrhage were obtained.

RESULTS

The blood loss was 4.5 ± 1.1 mL kg^-1 and 26.8 ± 5.5 mL kg^-1 for mild and severe haemorrhage events, respectively. The most significant variables with large effect sizes were heart rate (HR), systolic arterial blood pressure (SAP), end-tidal carbon dioxide (Pe'CO₂), serum albumin, haematocrit and actual bicarbonate ion concentration [HCO₃^-(act)]. The most robust ratios were: 1) shock index (d = -2.8; HR:SAP); 2) HR:Pe'CO₂ (d = -2.9); 3) serum albumin: haematocrit (d = 1.5); and 4) HR:HCO₃^-(act) (d = -1.6). These ratios were included in the final proposed Cat Acute Bleeding Scoring System (CABSS).

CONCLUSIONS

and clinical relevance Cats subjected to mild and severe haemorrhage demonstrated statistically and clinically relevant changes whereby four ratios could be created to make up the CABSS. The ratios detected and quantified the presence of severe haemorrhage in anaesthetized cats.

Dynamic left ventricular outflow tract obstruction secondary to hypovolemia in a German Shepard dog with splenic hemangiosarcoma

Dynamic left ventricular outflow tract obstruction (DLVOTO) is a common condition in cats and humans. In this case report, a dog is described with DLVOTO secondary to severe intra-abdominal hemorrhage caused by a hemangiosarcoma. The dog was a 9-year-old, 35.7-kg, spayed female German Shepard dog that presented with a history of tachypnea and collapse. A Levine II/VI systolic murmur was present at the heart base. Abdominal ultrasonography revealed a splenic mass and a large amount of ascites. Echocardiography showed a reduced left ventricular diameter and an increased aortic velocity caused by systolic anterior motion (SAM) of the mitral valve apparatus. The heart murmur and the SAM were resolved after treatment including a splenectomy and a blood transfusion.

Potential uses of recombinant human factor VIIa in veterinary medicine

In human beings, rFVIIa has been used successfully to promote hemostasis in patients with various bleeding disorders. Patients with hemophilia, thrombocytopenia, and thrombocytopathy have been effectively and safely treated as well as patients with severe trauma or surgery resulting in profuse bleeding and patients with impaired liver function. Given these successes, the possibility of using rFVIIa in veterinary medicine is appealing. The clinical indications and uses in veterinary medicine would be similar, but there are currently two major obstacles: immunogenicity and cost. If these problems can be addressed, rFVIIa may become a valuable and indispensable therapy, especially in the emergency and critical care settings. The use of rFVIIa could allow for successful treatment of otherwise intractable bleeding as well as decrease the number of blood transfusions needed.