Nurses guide to postoperative pain management in canines

Vet Times The website for the veterinary profession https://www.vettimes.co.uk Nurses guide to postoperative pain management in canines Author : Kerry Hall, Colette Jolliffe BVetMed Categories : RVNs Date : January 1, 2015 Kerry Hall Bsc(Hons), VN, DipAVN(Surgical), CertVN(ECC), VTS(ECC), offers advice to veterinary nurses on caring for pain-inflicted dogs, emphasising the importance of observation, communication and commencing postoperative care from the pre-operative period Reviewed by Colette Jolliffe BVetMed, CertVA, DipECVAA, MRCVS Summary Abstract POSTOPERATIVE pain management begins in the pre-operative period. The patient s degree of pain should be assessed, but pain assessment is very subjective. Effective communication is essential between veterinary nurses and veterinary surgeons. A multimodal approach should be undertaken. Key words Keywords: pre-emptive analgesia, multimodal analgesia, pain assessment THIS article will discuss postoperative (acute) pain management in dogs. The International Association for the Study of Pain defines pain as an unpleasant sensory and emotional experience, associated with actual or potential tissue damage, or described in terms of such damage. 1 / 14

Although the title of this article includes postoperative pain management, it is important to appreciate management begins in the pre-operative period. Pre-emptive analgesia, which can be defined as analgesia given before a noxious stimulus, reduces postoperative analgesic requirements, minimises detrimental effects of pain, improves patient handling, lowers sedation or anaesthetic requirements and reduces hypersensitisation (Shaffran, 2008). Multimodal analgesia refers to the practice of combining multiple analgesic drug classes or techniques to target different points along the pain pathway (Lamont, 2008). It would seem logical that using a combination of different drugs from different classes would be more effective and allow the use of lower doses, therefore reducing side effects. The RCVS Code of Professional Conduct states VNs must make animal health and welfare their first consideration when attending to animals. Veterinary nurses must take steps to provide pain relief to animals according to their skills and the specific situation. An analgesia plan should be devised pre-operatively for all elective procedures. Consideration should be given to the pre-operative stage, the peri-operative stage, the immediate postoperative period (in the hospital) and later on (at home). The plan should include the anticipated severity and duration of pain. Pain assessment Although it is of paramount importance for veterinary nurses to be able to recognise pain, this can be quite subjective. It is extremely useful to know normal breed behaviours. Some breeds for example, Dobermanns and huskies may be very vocal in a hospital environment (even when not in pain) and, as a result, are often considered more sensitive to pain. Other breeds, meanwhile, such as Labrador retrievers and bull terriers, are considered stoic, making pain assessment really difficult. Patients hospitalised prior to elective surgeries can be assessed as to what their normal hospital behaviour is. Are they calm and settled? Are they anxious and unsettled? How do they interact with staff? What is their appetite like? ( Figure 1 ). The Global Pain Council (GPC) was established by the World Small Animal Veterinary Association to develop pain assessment and treatment guidelines having universal relevance, taking into account regional differences in attitude, education and available analgesic modalities. The GPC recommend assessment of pain is incorporated into the temperature, pulse and respiration check, therefore making pain the fourth vital sign we should monitor for. We can t always know our patient does hurt, but we can do our best to ensure it doesn t hurt GPC (Mathews et al, 2014). 2 / 14

Signs of pain may include: change in body posture change in demeanour vocalisation change in reaction to people/handling As previously mentioned, pain assessment is subjective in our patients. Human patients can selfreport pain, which is the gold standard, but obviously this is not an option for our animal patients. How to perform a pain assessment At our clinic, the pain scoring assessment begins with observing the patient in the kennel, undisturbed. Questions to consider include: what is the dog s posture? is the dog vocalising? is the dog paying any attention to the surgical area? if this is an ophthalmology patient, is there any blepharospasm? ( Figure 2 a) The patient is then interacted with and consideration is given to the patient s behaviour. Does it appear depressed or disinterested? Does it appear nervous and anxious? Does it appear happy and content? ( Figure 2 b). The patient is then touched. The potentially painful area is palpated and the reaction noted ( Figure 2 c). A pain score is then assigned to the patient: 0 (no pain) to 10 (extreme pain). Even a score of 1 suggests the patient to be in pain (albeit mild), therefore further analgesia should be provided. A low score may be manageable with the addition of an NSAID or by increasing the dose or frequency of opioid administration (under veterinary supervision). The GPC guidelines suggest dogs should be assessed on a regular basis following surgery in the early recovery period every 15 to 30 minutes (depending on the surgical procedure) and on an hourly basis thereafter for the first six to eight hours. Thereafter, if pain is well controlled, three to six-hourly assessment is recommended. As part of this, it is also vitally important to re-check the patient on a regular basis even if analgesia has been administered. Regular assessment will allow for adjustments in analgesia 3 / 14

regime, such as increasing or decreasing infusion rates, the frequency of bolus dosing or the dose rate. It is important the pain scoring doesn t just become a box-ticking exercise. Ideally, the same person will perform the pain assessment to ensure continuity of care, but if there is any doubt as to the degree of pain, a second opinion should be sought. Understanding the patient s needs It is important for veterinary nurses to be confident in what questions to ask at handover. The following questions are aimed at surgical patients at a referral centre, so may not be applicable for all cases in general practice. What procedure has been performed? Veterinary nurses should be aware of what is involved in commonly performed procedures and the conditions/procedures where a greater degree of pain can be anticipated, such as spinal surgery, burns, ear canal ablations and aortic saddle thrombosis. What analgesic drugs have already been administered and when? Veterinary nurses should be aware of the commonly used analgesic agents in terms of routes of adminis tration, onset of actions, dose rates, duration of effect and potential side effects. They should also be aware of reversal agents that can be administered. Has an NSAID been administered? If not, is this because it is contraindicated? Contraindications may include renal disease, gastrointestinal disease, dehydration, hypovolaemia and concurrent use of steroids. Have any local anaesthetic blocks been performed? If so, what local anaesthetic agent has been used? VNs should be aware of the commonly used agents in particular, duration of effect and potential side effects. Has an epidural been administered? If so, what drugs have been administered? Are there any chest drains/wound soak catheters/epidural catheters ( Figure 3 ) in place? If so, what are the instructions for handling these and administering local anaesthetic agents? Is the patient to be started/continued on a constant rate infusion (CRI)? If so, what drug? What rate? Does a bolus need to be administered first? What are the potential side effects? CRIs allow a steady state of analgesia to be provided, thereby avoiding the peaks and troughs compared to bolus dosing. Drugs that can be administered via CRI include ketamine, morphine, lidocaine ( Figure 4 ) and alpha-2 agonists. Is the patient to receive bolus dosing of opioids? If so, what drug? What dose rate? How frequently? What route? Can any sedation be administered in recovery if needed? Has the patient s bladder been expressed? Especially if it had a long procedure/received large volumes of fluid therapy. It is important for veterinary nurses to be aware that if a veterinary licensed product exists, this 4 / 14

must be used. If there is no veterinary medicine authorised in the UK, the vet in charge may follow the cascade system to prescribe alternatives (visit www.bsava.com ). Nursing considerations to help alleviate pain and discomfort Provide the patient with a warm and quiet environment in which to recover. The kennel should be padded as appropriate. Ideally, dimmed lighting should be available and low-level music can be soothing for some patients. The patient should be given opportunity to toilet as soon as practicable. Offer food as soon as fully recovered (often, this will help settle a Labrador retriever). Give tender loving care (TLC). Warm/cold compresses/passive range of motion/hydrotherapy. Acupuncture. Frequent turning (at least every four hours) if recumbent will help reduce development of decubital ulcers and muscle stiffness. Medical massage may also be beneficial. This involves the manipulation of soft tissues to generate a change in texture, mobility, blood flow and lymphatic drainage and provide relief from stress, anxiety and pain. Stress and anxiety can intensify pain (Mathews et al, 2014). VNs will be able to take action, such as TLC, dimming the lights and decreasing loud noises to help alleviate these. Any particular special needs such as deafness or blindness should also be addressed. These patients may display signs such as vocalisation and anxiety that may be confused with pain. Although this article has focused on acute pain, consideration must be given to any concurrent chronic pain states (acute or chronic) such as osteoarthritis. It is recommended that for every time an animal is exposed to an uncomfortable situation, such as an intramuscular injection or rectal temperature, this should ideally be followed by three positive experiences such as TLC, feeding, taking it outside or grooming the three-one rule (Shaffran, 2008). Communication VNs are the primary care providers to hospitalsed patients. It is essential nurses have good knowledge of the physiology of pain and actions of the analgesics they are administering. Effective written and verbal communication is vital between the VN and the veterinary surgeon in charge of the case. If you are caring for a patient you believe to be in pain then this needs to be effectively communicated. Why do you think the patient is in pain? What is it doing? What analgesics have 5 / 14

already been given (and to what effect)? What else has been done to help with patient comfort? (Given the opportunity to toilet, food, TLC and so on). Vets should be able to trust nurses and this often has to be earned by displaying knowledge and competence. With these, vets will listen to the information given by their nurses and take action based on it. Effective communication is also vital between VNs at nursing ward rounds to ensure continuity of patient care. It should be communicated: what analgesic drugs the patient does and does not respond to what routes of administration are recommended what signs the patient displays when in pain In the later postoperative period the analgesia plan may be changed. Is the priority to provide a steady state of analgesia? Therefore, is a CRI the most appropriate? Or, is the priority to wean off analgesia, so a bolus dose (with increased time intervals/decreased dose) is most appropriate? Postoperative analgesia at home In most cases the priority will be to discharge the patient home as soon as possible. Until recently, options for analgesic agents to send the patient home with have been limited. Recuvyra contains fentanyl 50mg/ml as a transdermal solution for dogs. It is indicated for the control of postoperative pain associated with major orthopaedic and soft tissue surgery in dogs, when it would be anticipated the patient would require opioid analgesia for at least four days. Key points A single application should be administered topically to the dorsal scapular area (by a veterinary surgeon) two to four hours prior to surgery to provide analgesia for at least four days ( Figure 5 ). A minimum seven-day dosing interval must be observed. Dogs weighing more than 20kg must remain hospitalised for a minimum of 48 hours. There is a risk of small children who have direct contact with a dog more than 20kg treated with the product of having a serious exposure to fentanyl. VNs should be aware of the side effects observed with this drug. Common side effects include hypothermia, decreased respiratory rate, bradycardia and hypotension. Very common side effects include mild sedation (especially in the first 24 hours of application), loss of appetite and drinking less. 6 / 14

Patients weighing less than 20kg can be discharged when sedation is mild/absent and the patient is eating and drinking voluntarily. This provides an exciting opportunity to potentially discharge patients sooner, while still ensuring the patient is comfortable at home. Conclusion This article has highlighted the importance of the vital role VNs play in assessing patients for pain and in the provision of analgesia. References Lamont L A (2008). Multimodal pain management in veterinary medicine: the physiologic basis of pharmacologic therapies, The Veterinary Clinics of North America, Small Animal Practice 38(6): 1,173-1,186. Mathews K, Kronen P W, Lascelles D et al (2014). Guidelines for recognition, assessment and treatment of pain, Journal of Small Animal Practice 55(6): E10-E68. Shaffran N (2008) Pain management: the veterinary technician s perspective, The Veterinary Clinics of North America, Small Animal Practice 38(6): 1,415-1,428. 7 / 14

Figure 1. A puppy asleep and settled in hospital. 8 / 14

Figure 2a. When pain score assessing an ophthalmology patient, it is important to check for any blepharospasm. 9 / 14

Figure 2b. Check whether a patient seems both happy and content. 10 / 14

Figure 2c. Palpating a patient s potentially painful area and noting any reaction is useful in pain score assessment. 11 / 14

Figure 3. Epidural catheter. 12 / 14

Figure 4. Lidocaine constant rate infusion. 13 / 14