Does the idea of a dog presenting with pale mucous membranes, a weak pulse and a heart rate of 190 beats/min make your knees sweat? Do you get tachypneic when you see a dyspneic cat fish-mouth breathing in front of you?
If you don’t see emergency cases every day, you’re in the right place—this article discusses how to avoid common errors in emergency patients and save your patients’ lives. Having practiced everywhere from a busy inner-city emergency room to the ivory tower of academia, I’ve seen these mistakes made and I’ve made them myself.
Now you don’t have to—and your patients (or at least their owners) will thank you. Here’s what to avoid.
1. Not doing chest radiographs
I can’t tell you how many times I’ve had a case referred to the emergency clinic for abdominal ultrasound or postoperative supportive care, only to find a chest full of metastatic lesions. Chest radiographs need to be part of routine geriatric diagnostics.
Dogs older than 6 or 7 years of age and cats older than 12 with, for example, hepatosplenomegaly, icterus, hemoabdomen, immune-mediated disease or fever of unknown origin should have chest radiographs done at the same time as abdominal radiographs. Typically, a three-view chest set is the method of choice, but a right- and left-lateral chest radiograph is also an effective way to screen for metastasis.
While a met check is a “low-yield test” (the likelihood of identifying chest metastasis is relatively low), it’s an important screening tool that can help you counsel pet owners on end-of-life decision-making and overall prognosis. However, keep in mind that doing chest radiographs may be too stressful for dyspneic cats—stabilize them first.
2. Using the shock dose of fluids
The “shock dose” of fluids is extrapolated from a patient’s blood volume (60-90 ml/kg for dogs; 60 ml/kg for cats). But recently, emergency and critical care specialists have moved away from using the entire shock dose when trying to stabilize hypovolemic patients—smaller aliquots (one-quarter to one-third of a shock dose) of intravenous (IV) crystalloid fluids are preferred. Better to give small amounts frequently while monitoring!
3. Using the wrong dose of corticosteroids
Traditionally, emergency books have included “shock doses” of corticosteroids—for example, dexamethasone sodium phosphate (DexSP) 4-6 mg/kg. However, criticalists have moved away from giving corticosteroids with trauma because of potential deleterious effects, including gastric ulceration in a poorly perfused “shock gut” in the dog, exacerbation of hyperglycemia, and delayed wound healing.
Recently we have moved to administering different doses of DexSP. An anti-inflammatory dose of DexSP is generally considered 0.1 mg/kg, whereas immunosuppressive doses are as low as 0.25 mg/kg IV every 12 to 24 hours. For that reason, the 4-6 mg/kg dose for shock is no longer indicated. Remember that DexSP is approximately eight to 15 times stronger than prednisone.
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 hyperglycemia. Recent studies have shown that human patients with head trauma and hyperglycemia have a poorer return to cognitive function than do euglycemic patients. Why is hyperglycemia dangerous in these cases? Because elevated glucose concentrations provide a substrate for anaerobic metabolism and glycolysis in the brain. Hyperglycemia 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
Elevation of the head 15 to 30 degrees (to lower ICP)
Minimal jugular restraint or pressure (to prevent increased ICP)
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 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.
By avoiding these key common mistakes in emergency medicine, you can help more of your emergency patients survive.
1. Boysen SR, Rozanski, EA, Tidwell AS, et al. Evaluation of a focused assessment with sonography for trauma protocol to detect free abdominal fluid in dogs involved in motor vehicle accidents. J Am Vet Med Assoc 2004;225:1198-1204.
Note: When in doubt, all drug dosages should be confirmed and cross-referenced with a reference guide such as Plumb’s Veterinary Drug Handbook.