May 2025

In this VETgirl online veterinary continuing education blog, Lexi Dickens, BS, LVT, RVT, VTS (ECC) reviews shock in veterinary medicine. Last week, she reviewed the definition of shock, the pathophysiology of shock, and the stages/types of shock. In this two-part blog, she’ll focus on treatment of shock. If you haven’t read Part 1, make sure to read that first HERE!

By Lexi Dickens, BS, LVT, RVT, VTS (ECC)
Senior Patient Care Training Coordinator, BluePearl Pet Hospital, Cary, NC

Understanding Shock, Part 2

In a previous blog, we discussed types and stages of shock. Today, we’ll discuss initial diagnostic approach to the shocky patient and how to treat the shocky canine or feline patient.

Initial Interventions and Treatments

The most important aspect of treating shock is early recognition and rapid intervention. Continuous monitoring and frequent assessments of goal directed therapies can help clinicians form a complete treatment plan. Point of care testing should be done to aid in initial stabilization. At minimum, a PCV/TS, blood glucose, and plasma lactate should be obtained. It is ideal to complete additional labs, like an arterial or venous blood gas, electrolyte panel, complete blood count, and base line chemistry. In cases of hemorrhagic shock, it may be necessary to complete a prothrombin time (PT), partial thromboplastin time (PTT), and species-specific blood typing.

Other hands-on diagnostics that can help direct treatment are non-invasive blood pressure, pulse oximetry, and a focused assessment with sonography for trauma (FAST) of the abdomen (aFAST) and thorax (tFAST).1

Vascular Access

Vascular access is essential for treatment, regardless of the type of shock a patient is suffering from.1 Focus should be placed on obtaining access in the most appropriate place based on the type of shock and patient presentation. Most often, this will be a cephalic vessel. Placement of an additional intravenous catheter may be beneficial at presentation or after the patient has received initial treatment. Ideally, jugular venipuncture should be avoided in the emergent or critically ill patient in the event a central line must be placed later.

IV catheter supplies. Photo courtesy of Amanda M. Shelby.

Oxygen Therapy

Oxygen therapy can be beneficial to patients in shock as they have some level of hypoxemia. A few options for oxygen support include short term use of flow-by or a mask, and long-term use such as an oxygen cage or nasal cannulas. Based on the patient’s response, or failure to the initial oxygen therapy a secondary decision may need to be made if the patient would benefit from high flow oxygen therapy (HFOT). The benefit of HFOT is the ability to provide up to 100% fraction of inspired oxygen (FiO2), as well as providing small levels of positive end expiratory pressure (PEEP).1

Fixed PEEP valves. Photo courtesy of Amanda M. Shelby.

 

Volume Resuscitation

Volume resuscitation is a staple treatment with hypovolemic, obstructive, and distributive shock. The categories of fluid therapy that can be utilized are crystalloids, synthetic colloid solutions, and blood products. Crystalloids, such as Lactated Ringer’s solution (LRS), are commonly bloused in 10-20 mL/kg increments to help achieve normotension.1 A downfall of crystalloid fluid therapy is the brief time it spends in the vascular space before moving to interstitial spaces. Colloid solutions, such as Vetstarch®, contain larger molecules that help maintain intravascular volume and are given in smaller bolus such as 2.5-5 mL/kg.1 Synthetic colloids are less prevalent due to concerns for acute kidney injury (AKI), changes in coagulation ability, and increased mortality, especially in those that are critically ill.1

While synthetic colloid solutions have become less prevalent over time, natural colloid solutions such as blood or plasma products have fallen into favor. Blood products such as fresh whole blood (FWB), stored whole blood (SWB), packed red blood cells (pRBC), plasma products such as fresh frozen plasma (FFP), fresh plasma (FP), and serum albumin can be utilized to help volume resuscitate a patient.1 It is important to blood type your patient to ensure blood products are used responsibly, by providing type specific blood whenever possible in canine patients, and ensuring feline patients only receive type specific blood. Use of commercially available immunochromatographic in- house blood typing tests can provide rapid bed side results.2, 3 Patients that have a known history of blood transfusion should have a cross match performed prior to administration of another blood product.3

‘Tree of life support’ syringe pumps and fluid support for critical patient. Photo courtesy of Amanda M. Shelby.

If fluid therapy is not adequate in restoring a normal blood pressure, or the patient has refractory hypotension, other form of treatment such as vasopressors or inotropes can be considered. Depending on what is available you may consider medication such a norepinephrine (mixed adrenergic agonist), dopamine (catecholamine), dobutamine (beta-1 agonist), phenylephrine (alpha-1 adrenergic), or vasopressin (ADH).1 These medications are most administered as a CRI and some can cause phlebitis (or even necrosis) if given through a peripheral intravenous catheter. It is ideal to consider placement of a central venous catheter (CVC) or peripherally inserted central catheter (PICC).

Central venous catheter kit. Photo courtesy of Amanda M. Shelby.

Cardiogenic shock is the only form of shock that you would not administer additional fluids. By definition it occurs in the face of adequate vascular volume and is secondary to cardiac dysfunction.4 Focus of treatment in these situations is often diuretic therapy such as furosemide, or inotropic intervention such as dobutamine or pimobendan.

Pain Management

Pain management is one of the most important parts of treating any veterinary patient. Not only are there behavior changes when a patient is in pain, there are also physiologic changes. An example of a few physiologic changes seen in a painful patient as well as a patient in shock are tachycardia or tachypnea.5 With appropriate pain management it can be easier to determine if those abnormalities are stemming from pain, or another underlying cause. Upon initial triage it is common to administer a single agent for pain management such as methadone or hydromorphone. Once a patient has appropriate diagnostics and a treatment plan it is ideal to lean on multimodal analgesia to address various parts of the pain pathway, lessen side effects from higher doses of a single agent, and improve pain control.5 Appropriate pain management can help relieve stress and promote healing.

Continuous monitoring of a patient perfusion parameters, oxygenation status, electrocardiogram, repeated point of care ultrasounds, pain score, and point of care testing can allow for goal directed therapy. A patient’s response to interventions should be frequently communicated between the doctor and technician as they function together as the patients care team. Escalation of treatment for patients that may not response to the primary intervention can include vasopressor therapy, colloid administration, or blood product transfusions. 1, 6

Summary

The most successful cases of treating shock include early recognition, rapid and aggressive intervention, and continued monitoring and communication. Goal directed therapy allows the medical team to determine the success of current treatments as well as prognosis for survival.

Abbreviations

AKI: acute kidney injury
CO: cardiac output
CRI: constant rate infusion
CVC: central venous catheter
DO2: delivery of oxygen
FAST: focused assessment with sonography for trauma; of the abdomen (aFAST); thorax (tFAST)
FFP: fresh frozen plasma
FiO2: fraction of inspired oxygen
FP: fresh plasma
FWB: fresh whole blood
HFOT: high flow oxygen therapy
HR: heart rate
PICC: peripherally inserted central catheter
PEEP: positive end expiratory pressure
PT: prothrombin time
PTT: partial thromboplastin time
SWB: stored whole blood
SVR: systemic vascular resistance

References

  1. Arenth, J., Norkus, C. Shock and Initial Stabilization. In Veterinary Technician’s Manual for Small Animal Emergency and Critical Care (2nd ed), 17-34. Wiley; 2019.
  2. Yagi, K., Holowaychuk, M. Manual of Veterinary Medicine Blood Bank. Wiley
  3. Yagi, K., Spomber, L. Transfusion Medicine. In Veterinary Technician’s Manual for Small Animal Emergency and Critical Care (2nd ed), 505-530. Wiley; 2019.
  4. Brown, A., Madell, Cardiogenic Shock. In Small Animal Critical Care Medicine (2nd ed), 210-225. Wiley; 2015.
  5. Gottlieb, A. Pain Management for the Emergency and Critical Care Patient. In Veterinary Technician’s Manual for Small Animal Emergency and Critical Care (2nd ed), 479-503. Wiley; 2019.
  6. Laforcade, A., & Silverstein, D. C. Shock. In Small Animal Critical Care Medicine (2nd ed), 26–30. Wiley; 2015.

Please note that the opinions in this blog are expressed by the author, and not directly endorsed by VETgirl.

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