Pain Management In Cats Research Articles

Optimising postoperative pain management in cats undergoing ovariohysterectomy.

Optimising postoperative pain management in cats undergoing ovariohysterectomy.

Ex-vivo study of the percutaneous absorption of a tramadol formulation through feline inner pinna skin

ObjectivesOral medication of small animals, particularly cats, is often challenging. The transdermal route may provide an easier option for owners to administer chronic treatment. Tramadol is an analgesic mainly used in humans; it is also commonly used in dogs, despite some controversy over its clinical efficacy. Recent studies have suggested that tramadol is efficacious for pain management in cats. In cats, the inner pinna is the most commonly used site for transdermal drug therapy; the use of this site has been validated in experimental studies of methimazole and mirtazapine treatment. This ex vivo study aimed to characterise the percutaneous absorption pharmacokinetics of a formulation of tramadol in Pentravan through feline inner pinna skin. MethodsHigh-performance liquid chromatography was used to assess the stability of the tramadol formulation (100 mg/ml in Pentravan) over three months at room temperature. Forced degradation was also assessed in neutral, acidic, alkaline, and oxidative conditions. A Franz cell system was employed to evaluate percutaneous absorption of a finite dose of tramadol. ResultsThe tramadol formulation was stable for three months at room temperature. Tramadol penetrated through ex vivo feline inner pinna skin, but considerable intra- and inter-individual variability in kinetics was observed. Comparison with another vehicle, Lipoderm, revealed no significant difference in the percutaneous absorption of tramadol. Conclusions and relevanceThe Pentravan formulation assessed in this study supported tramadol absorption across the feline inner ear skin. In vivo studies are necessary to evaluate the pharmacokinetics and efficacy of this formulation.

Antinociceptive and analgesic effect of continuous intravenous infusion of maropitant, lidocaine and ketamine alone or in combination in cats undergoing ovariohysterectomy

BackgroundMultimodal analgesia consists of the combination of analgesic drugs at low doses to act in different places along the path of pain. Studies with continuous infusion of analgesic drugs in cats are not common. This study aimed to evaluate the analgesic effect of maropitant, lidocaine and ketamine alone or in combination (intravenous bolus + subsequent continuous intravenous infusion) in the management of acute postoperative pain in cats undergoing ovariohysterectomy. Seventy healthy cats undergoing an ovariohysterectomy received a standard anesthetic protocol consisting of acepromazine and morphine, propofol (anesthesia induction), and isoflurane (anesthesia maintenance). The animals were stratified into seven groups (n = 10 in each group): control (CG), maropitant (MG), lidocaine (LG), ketamine (KG), maropitant + lidocaine (LMG), maropitant + ketamine (KMG), and maropitant + lidocaine + ketamine (LKMG). All drugs were injected first as an intravenous bolus and then by continuous intravenous infusion. During surgery, esophageal temperature, respiratory rate, heart rate, oxygen saturation, expired isoflurane concentration, and partial pressure of carbon dioxide at the end of expiration were evaluated at 7 time points. Postoperative pain was evaluated for 6 h after extubation using the visual analogue scale and the UNESP-Botucatu multidimensional composite pain scale for assessing postoperative pain in cats.ResultsAdverse effects related to maropitant, lidocaine and ketamine infusion were not observed. Pain scores were lower in the MG, KG and LG groups when compared to the CG group using both scales. Although pain scores were also lower in all combination groups than CG, more animals in these groups required rescue analgesia compared to MG. This indicates that the postoperative analgesic effect of all drugs, either alone or in combination, confers analgesia, although the combinations did not promote greater analgesia.ConclusionsContinuous intravenous infusion of maropitant, lidocaine, and ketamine alone induces postoperative analgesic effect in cats undergoing ovariohysterectomy, but combinations of these drugs did not increase the analgesic effect. No adverse effect was observed with any drug or their combination.

Indicators of Health-Related Quality of Life in Cats With Degenerative Joint Disease: Systematic Review and Proposal of a Conceptual Framework

Objectives: The assessment of health-related quality of life (HRQoL) is becoming increasingly important in companion animals. This study describes a systematic review and development of a proposed conceptual framework to assess HRQoL in cats with osteoarthritis (OA).Methods: The conceptual framework was developed according to published guidelines. A comprehensive search of the CAB Direct, Scopus, PubMed, and Web of Science databases was carried out for publications in English from inception to November 12, 2019. Search words used were “cat”, “feline”, “chronic pain”, “pain”, and “quality of life”. Publications were selected if they were full-text and peer-reviewed, based on primary data, and identified or measured behavioral symptoms of chronic musculoskeletal pain in cats. A systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A data extraction form was developed from categories identified in the literature review and piloted on a small number of studies to ascertain the appropriateness for relevant data extraction. Categories were then finalized, and key domains were identified. The domains were then synthesized to develop a conceptual framework.Results: A total of 454 studies were identified, of which 14 met the eligibility criteria and were included in the meta-synthesis. All 14 were assessed to be of good quality. Seven domains related to HRQoL in cats with OA were thematically identified from the data: mobility, physical appearance, energy and vitality, mood, pain expression, sociability, and physical and mental wellbeing. The three main HRQoL domains were pain expression, mobility, and physical and mental wellbeing, which impacted all the others. Pain and mobility impacted all six other domains, with increased pain and decreased mobility negatively impacting physical appearance, energy and vitality, mood, sociability, and physical and mental wellbeing.Conclusions and Relevance: This is the first study to develop an evidence-based conceptual framework for the assessment of HRQoL in cats with OA. The proposed conceptual framework suggests that effective management of chronic pain in cats may improve their overall HRQoL.

Attitudes and practices of veterinarians in Australia to acute pain management in cats.

ObjectivesUp-to-date information on the current practices and attitudes of veterinarians in Australia to acute pain management in cats was sought in 2017–2018 in the first nationwide survey in over 20 years.MethodsAn online survey was created, consisting of 54 questions in four sections, with 18 feline-specific questions. Veterinarians throughout Australia were invited to participate in the survey through advertisements in the veterinary press, electronic and regular mail, and through in-clinic visits and promotional materials.ResultsA total of 614 veterinarians completed the survey, with 513 (83.6%) completing the feline-specific section. The demographics of the respondents of this survey were an accurate representation of the registered veterinarians in Australia at the time. Multiple different opioids and non-steroidal anti-inflammatory drugs (NSAIDs) were widely available in practices to manage pain, with analgesic efficacy reported as the primary factor influencing drug selection. Opioids were most commonly used in the preoperative period and NSAIDs were most commonly used postoperatively. Despite the wide availability in clinic (>99%), only 55% of respondents reported regularly using local anaesthetic techniques in cats. Pain assessment of hospitalised patients was primarily performed by veterinarians (91.1%); however, 84.7% of respondents did not routinely use a validated pain scale.Conclusions and relevanceVeterinary practitioners in Australia are adequately equipped with analgesic medication to treat pain in their patients. In the management of acute pain in cats, they frequently use a multimodal approach and practice a variety of analgesic protocols. Based on the results of this survey, potential areas for improvement in feline pain management include an increase in duration of postoperative analgesia and more routine use of validated pain scales, performed by nurses and veterinarians alike, to assess individual analgesic needs.

Pain management in cat

Although cats are very popular pets, pain in this species is often underestimated. The reasons for this may include difficulties in pain recognition, unfamiliarity with the use of opioids or non-steroidal analgesic drugs, and with the application of local analgesic techniques. Proper pain management should always be undertaken mainly for medical and humane purposes. Pre-emptive and multimodal analgesia can aid significanly in postoperative pain alleviation. Nowadays, the veterinarian's armamentarium is equipped with a variety of agents in order to alleviate pain in cats. Non-steroidal anti-inflammatory drugs are often as effective as opioids. The latter are now used successfully for pain management in cats. Both classes provide safe analgesia, taking into account the differences in metabolism between cats and other species. Adjunctive analgesic therapy may be provided with the use of ketamine or a2-adrenergic receptor agonists. Loco-regional analgesic techniques can be used to effectively manage pain in a variety of clinical settings.

Yamamoto New Scalp Acupuncture for postoperative pain management in cats undergoing ovariohysterectomy

ObjectiveTo evaluate the analgesic efficacy of Yamamoto New Scalp Acupuncture (YNSA) as an adjuvant for postoperative pain management in cats. Study designProspective, randomized, blinded, clinical study. AnimalsTwenty cats aged (mean ± standard deviation) 25 ± 9 months and weighing 2.7 ± 0.6 kg undergoing ovariohysterectomy. MethodsThe cats were sedated with intramuscular (IM) ketamine (5 mg kg−1), midazolam (0.5 mg kg−1) and tramadol (2 mg kg−1). The cats were randomly distributed before induction of anesthesia into two groups of 10 cats each: group YNSA, in which bilateral basic D points were stimulated with a dry needle from 20 minutes prior to anesthetic induction to the end of the surgery; group Control, in which no acupuncture was applied. Postoperative analgesia was assessed at 1, 2, 4, 8, 12, 18 and 24 hours postextubation using an Interactive Visual Analog Scale and Universidade Estadual Paulista-Botucatu Multidimensional Composite Pain Scale (UNESP-Botucatu MCPS). Rescue analgesia was provided with IM tramadol (2 mg kg−1), and the pain scores were reassessed 30 minutes after rescue intervention. If the analgesia remained insufficient, meloxicam (0.2 mg kg−1 as a single dose) was administered IM. Data were analyzed using Student t-test, Fisher exact test, Mann–Whitney U test and Friedman test (p < 0.05). ResultsSignificantly lower pain scores were observed in YNSA when compared with Control at 1–4 hours based on the UNESP-Botucatu MCPS scores. Although significant differences were not identified between groups requiring rescue analgesia, additional postoperative analgesia was administered to four of 10 cats in Control and no cats in YNSA. Conclusion and clinical relevancePerioperative YNSA resulted in decreased pain scores and a reduction in postoperative requirement for rescue analgesia in cats. This method should be considered a viable option as an adjuvant analgesic therapy for cats undergoing ovariohysterectomy.

Practical use of opioids in cats: a state-of-the-art, evidence-based review.

Recent recognition of the need to improve pain management in cats has led to the investigation of the pharmacokinetics and efficacy of opioid analgesic drugs in this species. The results of these studies may be difficult to interpret because the effect of these drugs varies with dose, route of administration and the method used to assess them. As equipotency of different opioids is not known, it is hard to compare their effects. Animals do not verbalise the pain they feel and, in cats, it may be more difficult to recognise signs of pain in comparison with other species such as dogs. This article reviews the use of opioid analgesics in cats. It must be remembered that not all drugs are licensed for use in cats, and that marketing authorisations vary between different countries.

Beyond-use date determination of buprenorphine buccal solution using a stability-indicating high-performance liquid chromatographic assay.

The objectives of this study included developing and validating a stability-indicating high-performance liquid chromatographic (HPLC) method with ultraviolet (UV) detection for the determination of buprenorphine in a buccal solution for veterinary use, and applying that method to determine the stability of a 3 mg/ml buprenorphine preparation in room temperature and refrigerated storage conditions. This preparation, intended for buccal administration in feline patients, plays an important role in pain management in cats. A stability-indicating HPLC method was developed and validated for system suitability, accuracy, repeatability, intermediate precision, specificity, linearity and robustness based on US Pharmacopeia (USP) General Chapter <1225>. The method was then applied to the study of potency changes over 90 days in a buccal buprenorphine solution stored at two temperatures. All HPLC-UV method data met acceptable criteria for the quantification of buprenorphine in a buccal solution formulation. The buprenorphine concentrations found in each stability sample remained within the 90-110% of label claim throughout the 90 days of study. All stability test bottles of the buprenorphine buccal solution retained their original appearance. For the room temperature bottles, some white particulate matter was noted in the threads of the container bottles starting at day 21. The pH of the preparations during the course of the study was in the range of 3.57-4.06 and 4.01-4.16 for the room temperature and refrigerated samples, respectively. Pharmacists have compounded a concentrated 3 mg/ml buccal solution to use easily in the home care or outpatient setting for treatment of feline pain. Prior to this investigation, pharmacists empirically assigned beyond-use dates to this formulation based on standards in USP General Chapter <795> Pharmaceutical Compounding - Nonsterile Preparations. This study of a 3 mg/ml buprenorphine buccal solution indicates stability through 90 days.

Laser Acupuncture for Postoperative Pain Management in Cats.

The aim of this study was to evaluate laser acupuncture as an adjuvant for postoperative pain management in cats. Twenty cats, undergoing ovariohysterectomy, were sedated with intramuscular (IM) ketamine (5 mg kg−1), midazolam (0.5 mg kg−1), and tramadol (2 mg kg−1). Prior to induction of anaesthesia, the subjects were randomly distributed into two groups of 10 cats: Laser: bilateral stomach 36 and spleen 6 acupoints were stimulated with infrared laser; Control: no acupuncture was applied. Anaesthesia was induced using intravenous propofol (4 mg kg−1) and maintained with isoflurane. Postoperative analgesia was evaluated by a blinded assessor for 24 h following extubation using the Dynamic Interactive Visual Analogue Scale and Multidimensional Composite Pain Scale. Rescue analgesia was provided with IM tramadol (2 mg kg−1), and the pain scores were reassessed 30 min after the rescue intervention. If the analgesia remained insufficient, meloxicam (0.2 mg kg−1 IM, single dose) was administered. Data were analyzed using t-tests, the Mann-Whitney test, and the Friedman test (P < 0.05). The pain scores did not differ between groups. However, postoperative supplemental analgesia was required by significantly more cats in the Control (5/10) compared with the Laser group (1/10) (P = 0.038). Laser acupuncture reduced postoperative analgesic requirements in cats undergoing ovariohysterectomy.

Evidence Based Alternative Medicines in Pain Management.

Evidence Based Alternative Medicines in Pain Management.

Plasma concentrations and behavioral, antinociceptive, and physiologic effects of methadone after intravenous and oral transmucosal administration in cats

To determine plasma concentrations and behavioral, antinociceptive, and physiologic effects of methadone administered via IV and oral transmucosal (OTM) routes in cats. 8 healthy adult cats. Methadone was administered via IV (0.3 mg/kg) and OTM (0.6 mg/kg) routes to each cat in a balanced crossover design. On the days of drug administration, jugular catheters were placed in all cats under anesthesia; a cephalic catheter was also placed in cats that received methadone IV. Baseline measurements were obtained ≥ 90 minutes after extubation, and methadone was administered via the predetermined route. Heart and respiratory rates were measured; sedation, behavior, and antinociception were evaluated, and blood samples were collected for methadone concentration analysis at predetermined intervals for 24 hours after methadone administration. Data were summarized and evaluated statistically. Plasma concentrations of methadone were detected rapidly after administration via either route. Peak concentration was detected 2 hours after OTM administration and 10 minutes after IV administration. Mean ± SD peak concentration was lower after OTM administration (81.2 ± 14.5 ng/mL) than after IV administration (112.9 ± 28.5 ng/mL). Sedation was greater and lasted longer after OTM administration. Antinociceptive effects were detected 10 minutes after administration in both groups; these persisted ≥ 2 hours after IV administration and ≥ 4 hours after OTM administration. Despite lower mean peak plasma concentrations, duration of antinociceptive effects of methadone was longer after OTM administration than after IV administration. Methadone administered via either route may be useful for perioperative pain management in cats.

Recent advancements in the management of pain in cats and dogs.

Abstract Dogs and cats are popular pets and it is estimated that over one-third of households in the USA own a cat or dog, with an estimated national population of approximately 72 million dogs and 83 million cats. Many of these animals will undergo a surgical procedure such as an ovariohysterectomy or castration and because pets are living longer, chronic pain, for example that related to osteoarthritis, is of concern in senior animals. The number of published papers related to the recognition and treatment of pain in cats and dogs continues to grow exponentially; this is encouraging for those involved in small animal practice but keeping abreast of new developments can be a challenge. This review aims to discuss the value of current methods and to highlight new and emerging ideas in pain management for cats and dogs. Key topics include the physiology and pathobiology of pain, behaviour-based assessment of pain, the importance of pre-emptive treatment, the differences in the pharmacokinetics of drugs between cats and dogs and the place of complementary modalities such as acupuncture in veterinary pain management.

Pain management in cats—past, present and future. Part 1. The cat is unique

Cats are popular pets but until recently their perioperative and traumatic pain was seriously underestimated and under treated. There are several causes of this under treatment. First, it may be difficult to detect pain in cats, because they do not demonstrate overt pain-associated behaviour. Secondly, there are relatively few analgesic drugs with market authorisation for cats. Thirdly, cats have an unfortunate reputation for toxicity from analgesic drugs, particularly opioid-induced mania and classical non steroidal anti inflammatory drug toxicity. Fourthly, cats are deficient in some metabolic pathways used to metabolise analgesic drugs in other species; this may lead to genuine toxicity or to lack of effect. Recently, understanding of feline behaviour and physiology has improved, leading to better clinical management of this enigmatic species. Behavioural methods are proving to be the best means of assessing pain, and knowledge of unique feline physiology has enabled rational treatment protocols to be developed specifically for cats.

Pain management in cats—past, present and future. Part 2. Treatment of pain—clinical pharmacology

Opioids have an unjustified reputation for causing mania in cats, but with refinements in dosing they are now used successfully in this species. The mu-opioid agonists are generally considered the best analgesics. Morphine (0.1–0.3 mg/kg) is effective in a clinical setting. Methadone (up to 0.5 mg/kg) has a similar profile to morphine. Pethidine (Demerol, meperidine; 2–5 mg/kg) is a useful analgesic with a faster onset but shorter duration of action than morphine. Oxymorphone and hydromorphone (0.05–0.1 mg/kg) are widely used in the USA. These opioids are more potent (up to 10 times), and longer acting than morphine in cats. Butorphanol (0.1–0.4 mg/kg) is a mu-opioid antagonist that produces its analgesic actions through kappa agonist activity. It rapidly reaches a ceiling effect, is short acting and is a weaker analgesic than pure mu opioids. Buprenorphine (0.01–0.02 mg/kg), a partial mu-agonist, is the most popular opioid used in small animal practice in the UK, other parts of Europe, Australia and South Africa. In clinical studies it has produced better analgesia than several other opioids and appears to be highly suitable for perioperative pain management in cats. NSAIDs are also used in cats for pain management, although cats metabolise these differently from other species. With appropriate dosing, carprofen (1–4 mg/kg) and meloxicam (0.3 mg/kg) have proved highly effective with few side effects. The use of ketoprofen (2 mg/kg), tolfenamic acid (4 mg/kg) and vedaprofen (0.5 mg/kg) has been reported in cats. Other less traditional analgesics such as ketamine, medetomidine and local anaesthetics are also used for clinical pain management. The transmucosal, transdermal and epidural routes offer novel methods for administration of analgesic drugs and have considerable potential for improving techniques in feline pain management.