Pain management in the emergency or critical care setting

It can be difficult for clients to understand if pets are in pain or not

It can be difficult for clients to understand if pets are in pain or not. Compare what the animal might be feeling to something a human can relate to so they get a sense of what is needed to treat the pain. Photo ©BigStockPhoto.com
It can be difficult for clients to understand if pets are in pain or not. Compare what the animal might be feeling to something a human can relate to so they get a sense of what is needed to treat the pain.

Pain has become known as the fifth vital sign and is now assessed in addition to temperature, pulse, respiratory rate, and blood pressure. One study showed 56 percent of dogs and 54 percent of cats were painful when they presented to the emergency service.1

Pain assessment can be difficult, even more so in a patient that has experienced trauma or is anxious and frightened. Pain assessment is beyond the scope of this article but there are a wide variety of pain assessment protocols available to assist with assessment and response to pain management.2

Analgesic needs

One study showed that, while most owners understand a surgical procedure requires analgesia, they do not all believe an ear infection is painful or lameness indicates pain.3 Many owners do not understand what pain looks like in their pets and do not believe their pets are painful unless they can see the injury.3

Emphasizing pain management when the patient is initially assessed will keep the door open to continue the conversation when the patient is hospitalized and/or discharged. It is often helpful to compare patients’ condition to something owners may be familiar with (i.e. a twisted ankle or earache) to help them understand the degree of pain their pet is experiencing.

When a technician speaks to an owner and the history implies the patient may be painful, they can briefly mention analgesia to the owner, opening the door for future discussions with the doctor. If the technician retrieves a painful patient from a car, they should get permission to place an IVC and give pain medications, making sure the owner understands analgesics will only be given if the veterinarian deems it appropriate.

There is always the owner who will not give permission without speaking to the doctor first. If this is the case, the doctor should address analgesia as soon as possible. While it is the owner’s choice, compliance may be increased if pain management is presented as a necessary treatment rather than an option.

Pain can be difficult to assess in nervous, frightened, aggressive, or stoic patients. Therefore, it is best to assume anything appearing painful is painful and that some level of pain exists until proven otherwise.

The patients seen at the ER can experience anything from mild to severe pain, and pain management is often a challenge, requiring a multimodal approach. For this reason, most emergency hospitals keep a variety of analgesics on hand.

Several analgesic options are available to be used on initial evaluation. Dogs usually do well with hydromorphone or methadone, both of which are fast acting and last several hours. Hydromorphone should be avoided if the side effects (i.e. panting) would be detrimental to the patient.

Opioids are a good option for moderate to severe pain in cats (including fentanyl, hydromorphone, oxymorphone, and methadone) although morphine, hydromorphone, and oxymorphone can cause nausea, ptyalism, and vomiting.

Methadone does not typically cause these side and is an excellent choice for cats on presentation and during hospitalization.4 Methadone at a dose of 0.05-0.5mg/kg IV or IM can be administered as often as every four hours.5 

Hospitalization

Multi-modal pain management is advantageous as it decreases the amount of any one drug required.

Because they provide a consistent dose of analgesia, CRIs (constant rate infusion) are commonly used for hospitalized patients. If a CRI pump is not available, intermittent injections of a longer acting analgesic can be used (i.e., methadone or hydromorphone).

Fentanyl at a dose of 2-4mcg/kg/hr should provide excellent relief for severe pain. Because of its short half-life of approximately 45 minutes, it should be used for short procedures or as a CRI.5

A lidocaine bolus of 1-2mg/kg followed by a CRI at 25-50mcg/kg/min can be used in addition to fentanyl and will provide adjunctive analgesia for abdominal pain not well controlled with an opioid alone.5

Ketamine, which does not fall under the category of analgesia, can be used as an adjunct therapy for hyperalgesia or persistent post-operative pain unresponsive to opioids.6 The recommended dose is a bolus of 0.5mg/kg followed for by a CRI at 0.1-0.6mcg/kg/min.5

If the patient can tolerate (and adequately absorb) oral medications, gabapentin, tramadol, or an NSAID can be started before the patient is off intravenous medications, providing a smooth transition from intravenous to oral pain management. Tramadol has fallen out of favor as a stand-alone analgesic unless used for mild pain. Gabapentin, while still controversial, has taken tramadol’s place as the go-to analgesic to send home with patients. The combination of gabapentin with an NSAID (i.e. carprofen in dogs or meloxicam in cats) will likely provide adequate pain relief for patients when they are discharged. 

Nursing care

Nursing care is vitally important. Performing PROM and massage will contribute to patient comfort as will ensuring the animal has a comfortable bed, is being rotated (if recumbent), and is in a comfortable position. Nurses can advocate for their patients by asking for additional analgesics, placement of a urinary catheter in recumbent patients, or the removal of any tubes or drains no longer necessary. If placement of a urinary catheter is contraindicated, monitoring the patient’s urination and expressing the urinary bladder as needed should alleviate anxiety and increase the patient’s comfort.

Reducing stress reduces anxiety and allows patients to relax, enabling pain medications to be more effective. Housing cats away from barking dogs or noisy areas and giving them a box to hide in will help relieve stress. If the patient is finally comfortable and a scheduled treatment is not time sensitive, it is advantageous to wait, allowing the patient to rest. Cats can be given gabapentin to mitigate stress and fear, as well as provide post-operative analgesia.4 Some dogs will benefit from trazadone for anxiety.5

Technicians should be trained to calculate dosages quickly and accurately as most patients are painful when they come in and need pain medications quickly. While there are several CRI calculators available, the ability to calculate a CRI is a valuable skill and technicians should be encouraged to learn and perfect this skill.

Pain management can be a challenging aspect of veterinary medicine. The variety of medications available provide the clinician with a multitude of options, which can be tailored to each individual patient’s needs. Client education can increase compliance and the comfort of their pets, which increases their satisfaction. Each patient should be looked at as an individual and falling into the rut of treating each patient the same should avoided.

Brandy Tabor, CVT, VTS (ECC), graduated from Colorado State University in the spring of 2003 with a BS in equine sciences. While attending CSU, she worked as a nurse’s assistant in the critical care unit at the Colorado State University Veterinary Teaching Hospital, where she learned how far one can go as a veterinary technician. Upon graduating from the veterinary technician program at Front Range Community College, Tabor moved to Parker, Colo., and began her career as a CVT at Animal Emergency & Specialty Center. She is currently the head technician of the ER/ICU at AESC. She had the honor of becoming a member of the Academy of Veterinary Emergency & Critical Care Technicians and Nurses in 2008.

References

  1. Ashley J. Wiese, B., William W. Muir III, & Thomas E. Wittum, P. Characteristics of pain and response to analgesic treatment in dogs and cats examined at a veterinary teaching hospital emergency service. Journal of the American Veterinary Medical Association. 2005 June
  2. James S. Gaynor, Handbook of Veterinary Pain Management. 3rd ed. 2015. Elsevier Mosby.
  3. Simon BT, Perceptions and opinions of pet owners in the United Sates about surgery, pain management, and anesthesia in dogs and cats. Veterinary Surgery. 2018 47(2), pp. 277-284. July
  4. Paulo V. Steagall, 2020. Analgesia What Makes Cats Different/Challenging and What is Critical for Cats?. Veterinary Clinics of North America Small Animal Practice. 2020. 50(4), pp. 749-767.
  5. Anon., 2021. Plumb’s Veterinary Drugs, s.l.: Brief Media.
  6. Merk E. Epstein, Ketamine: To Use or Not to Use for Pain Management. Today’s Veterinary Practice. 2011 Vol. July/August.
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