Vet360 Vet360 Vol 05 Issue 04 - Page 14

EMERGENCY MEDICINE animal is in shock, it’s vasoconstricting to shunt blood to its most important organs—the heart and lungs. If the gut and kidneys aren’t getting appropriate blood flow during a shocky state, we ideally want to avoid NSAIDs or steroids until the patient is more stable. When in doubt, perfuse the patient first. Again, it’s not corticosteroids or NSAIDs that save these patients. It’s perfusion, perfusion, perfusion. 4. Giving corticosteroids to head trauma patients In the patient with head trauma, we ideally want to avoid the use of corticosteroids due to the potential for hyperglycaemia. Recent studies have shown that human patients with head trauma and hyperglycaemia have a poorer return to cognitive function than do euglycaemic patients. Why is hyperglycaemia dangerous in these cases? Because elevated glucose concentrations provide a substrate for anaerobic metabolism and glycolysis in the brain. Hyperglycaemia is also associated with proconvulsant effects due to increased neuronal excitability. Instead of reaching for corticosteroids in the head trauma patient, consider these treatments instead: • • • • • • Osmotic agents such as mannitol, which have been found helpful in decreasing intracranial pressure (ICP) IV fluid resuscitation to help normalize or maintain blood pressure and maximize perfusion Oxygen therapy Elevation of the head 15 to 30 degrees (to lower ICP) (Elevate without kinking the neck as kinking will actually increase ICP. Ed) Minimal jugular restraint or pressure (to prevent increased ICP) (Preferably use cephalic veins for IV access and blood collection - Ed) Tight glycemic control 5. Not doing FAST ultrasounds The focused assessment with sonography for trauma (FAST) ultrasound is a two-minute procedure that detects the presence of fluid in the abdominal cavity to allow for rapid therapeutic intervention, such as fluid resuscitation, abdominocentesis, cytology or clinicopathologic testing. 1 This quick ultrasound method to determine “yes fluid/no fluid” is designed to be used by healthcare professionals with limited ultrasonographic training and is not designed for extensive examination of the abdomen. One of the benefits of the FAST examination is its ability to detect very small amounts of fluid. Typically, 5 to 25 ml/kg of fluid needs to be present to be removed by blind abdominocentesis; 10 to 20 ml/kg of fluid has to be present before it can be detected by fluid-wave assessment on physical examination; and approximately 9 ml/kg of fluid needs to be vet360 Issue 04 | SEPTEMBER 2018 | 14 FELINE MEDICINE present before it can be detected radiographically. But as little as 2 ml/kg of fluid can be detected on a FAST examination, allowing for rapid diagnosis and identification of underlying pathology. The FAST examination typically involves assessment of four sites of the abdomen: caudal to the xiphoid, cranial to the bladder, and the right- and left- dependent flank. 1 The presence of fluid at any of these sites is considered positive. Evaluation of the xiphoid region allows you to check for fluid between the liver and diaphragm and the liver lobes, as well as for pericardial or pleural effusion. 1 The bladder view evaluates for fluid cranial to the bladder and for the presence of a bladder. 1 The right-dependent flank allows for fluid detection between the intestines and the body wall, whereas the left-dependent flank view allows for identification of the spleen and any abdominal effusion near the spleen and body wall, the kidney and spleen, and the liver and spleen. 1 6. Reluctance to penetrate body cavities I believe every veterinarian should be comfortable doing an abdominocentesis and a thoracocentesis. These benign procedures are both diagnostic and therapeutic. Moving quickly but maintaining aseptic protocol, shave and surgically prep a wide area near the umbilicus (for abdominocentesis) or thorax (for thoracocentesis). Thoracocentesis should be performed either dorsally (for air) or ventrally (for effusion) at the seventh to ninth intercostal space (ICS). An imaginary line can be drawn from the end of the xiphoid to the lateral body wall, which is approximately the eighth ICS. This allows for rapid identification of where to perform an emergency thoracocentesis. For an abdominocentesis, a four- quadrant tap should be aseptically performed at the periumbilical region. ABDOMINOCENTESIS TECHNIQUE An abdominocentesis should be performed using sterile technique. The abdomen should be clipped, shaved and prepared aseptically. A four quadrant tap around the umbilicus should be performed. If you obtain fluid from one location, there is no reason to tap the other remaining 3 regions. Gently, but briskly, insert a sterile 22-ga. needle into these locations. One can use either a closed technique (e.g., needle attached to 3 ml syringe) or open technique (e.g., needle alone). If no fluid is obtained, a “2-tap technique” can be used; a second needle can be inserted several millimeters away from the first sterile needle insertion - this will often allow fluid to gently flow out. Once fluid is seen, gentle suction can be used with an attached 1-, 3- or 6-ml syringe to aspirate the ascites. Editor References available online: www.vet360.vetlink.co.za