HBC enters your clinic quiz

HBC enters your clinic: a ste-by-step approach

By Amy Breton, CVT, VTS (ECC)Veterinary Emergency & Specialty Care Center of New England

All pets that have been hit by cars (HBC) are emergencies. When animals experience blunt trauma, adrenaline is usually released in large quantities.  It acts as a pain reliever and helps to elevate the heart rate.  As a result, the animal may be hit and then act as if nothing happened.  This natural reaction can mask underlying signs, such as pulmonary contusions or internal bleeding. 

Immediately upon a HBC pet’s arrival a veterinarian should be notified.  In the meantime, non-invasive treatments should begin.

Assessing respiration, alertness, and perfusion (RAP system) is one of the fastest and most effective ways to triage. In most cases the pet is experiencing shock and will require emergency treatment. 

1. Triage using R.A.P.  Minimally obtain heart rate, pulse, mucous membrane colour and note respiratory effort.

2. Notify the owner of WHY, WHAT, HOW MUCH.

  • Get a signed form that allows you to treat

3. Obtain blood pressure, pulse ox, and attach ECG.

4. Administer oxygen if in shock, respiratory distress, or if you are unsure of pet’s condition.

Obtain official set of vitals (T, P, R) if there is time and if it is appropriate.

  • (If pet is in the decompensatory or terminal stage of shock procede to step 6)

Initiate CPR immediately at any point if pet arrests

  • Temperature

  • Heart rate with pulses
  • Respiratory rate with effort
  • Mucous membranes
  • Mentation
  • Capillary refill time

6. Place IV catheter(s), attach 3cc syringe and draw back to obtain ideally 3ml of blood.

  • Run PCV, TS, BG
  • Run any other bloodwork prescribed by veterinarian

7. Start fluid therapy if appropriate and consider pain medication.

8. Obtain approval for other treatments (radiographs, ultrasound, medications).

  • Update owner on pet’s status

Veterinarian should have a basic prognosis and should speak to owner at this point.          

10. Continue to work on stabilizing pet.

  • Prepare pet for hospitalization and further treatments

One of the first challenges involves dealing with the client’s reaction. It is important to remember to maintain a calm and professional attitude at all times.  Pet owners should be informed in a clear concise manner of why their pet needs emergency treatment, what is going to be done to their pet, and how much it is going to cost (rough estimate). The hospital staff should clearly explain what procedures will take place, to help avoid confusion as well as help to protect the practice and staff involved. As well, the client should be asked to sign a consent form for any treatment provided.

Oxygen is important for any patient in shock or respiratory distress and should be provided.  Depending on the nature of the emergency, collecting vital statistics may or may not be possible right away. For example, obtaining a temperature or capillary refill time may not be as important as initiating CPR.  When appropriate all vitals should be obtained at some point.  In addition to performing a full physical exam, blood pressure, ECG, and pulse oximeter percentage should be measured and recorded. 

Gaining venous access is important in all HBC pets.  Studies have shown that short, large diameter catheters allow for higher fluid flows, and increasing the diameter of the catheter by one size can cut the time it takes to bolus a litre of fluids by half.  This may mean the difference between life and death for a patient.  In hemodynamically unstable patients, a smaller gauge catheter may have to be used due to smaller-than-normal vein size or poor integrity of the vessels.  If venous access is too difficult to obtain, a cut-down or intra-osseous catheter should be considered.

When the peripheral catheter is placed, blood should be drawn before any fluids are initiated as this is the fastest way to obtain blood without performing another venipuncture stick.  All emergency patients should have a packed cell volume (PCV), total solids (TS) and blood glucose performed.  The veterinarian may prescribe other bloodwork for the pet (CBC, chemistry, blood gas). 
If blood cannot be obtained through the IV catheter, IV fluids should be initiated.  Once the patient is stable it may be easier to obtain blood from another peripheral vein.

It is important to treat pain as soon as possible to avoid it escalating and causing shock.  It has been proven that recovery time is greatly reduced when pets experience less pain. Opioids are useful because they have limited effects on hemodynamics.

While obtaining radiographs or an ultrasound may yield a better diagnostic picture, it is always important to stabilize the patient first. A team member should alert the owner as to the pet’s status, what is being done to help the pet, and how long it will be until the veterinarian is able to speak with them.

IV fluids

There are two types of fluids that can be given:  crystalloids (the most common) and colloids.

There are three types of crystalloids:  isotonic (LRS, Norm-R, P-Lyte), hypertonic (7-7.5% NaCl), and hypotonic (0.45% NaCl).  Isotonic crystalloids are still the most commonly used.  Like the body’s extracellular fluid, they contain similar electrolyte concentrations (sodium, chloride, potassium, magnesium, calcium, and bicarbonate-like anions). 

Isotonic crystalloids distribute rapidly; within 30 minutes 75-98% of the fluids shift into the extravascular space.  Large volumes are needed in order to make a difference and the infusion must be continuous.

Hypertonic fluids contain a higher osmotic pressure than isotonic. 
The use of hypertonic saline is also known as limited-volume resuscitation and is currently recommended in head trauma cases.  It helps to reduce cerebral swelling without worsening edema.

Hypotonic fluids contain a lower osmotic pressure than isotonic (
5% dextrose in water, 0.45% NaCl).  Hypotonic fluids s
hould NOT be used to treat shock because they c
ontain too much water and will redistribute too quickly.

Colloids (hetastarch, albumin, plasma, blood) are high molecular weight fluids that do not pass readily through the capillary membranes.  Colloids help to increase oncotic pressure because they keep fluids in the intravascular space.  Roughly 50-80% of the infused volume stays in the intravascular space. 

After stabilization

The emergency patient becomes a hospitalized patient once stabilized, defined by normal blood pressure, appropriate mentation, normal heart and respiratory rate, pink mucous membrane colour, normal capillary refill time, and normal temperature. 


This article is based on a presentation given at The Veterinary Emergency and Critical Care Society Conference in San Antonio, TX. CVT