2022 ISFM Consensus Guidelines on the Management of Acute Pain in Cats

Practical relevance: Increases in cat ownership worldwide mean more cats are requiring veterinary care. Illness, trauma and surgery can result in acute pain, and effective management of pain is required for optimal feline welfare (ie, physical health and mental wellbeing). Validated pain assessment tools are available and pain management plans for the individual patient should incorporate pharmacological and non-pharmacological therapy. Preventive and multimodal analgesia, including local anaesthesia, are important principles of pain management, and the choice of analgesic drugs should take into account the type, severity and duration of pain, presence of comorbidities and avoidance of adverse effects. Nursing care, environmental modifications and cat friendly handling are likewise pivotal to the pain management plan, as is a team approach, involving the cat carer. Clinical challenges: Pain has traditionally been under-recognised in cats. Pain assessment tools are not widely implemented, and signs of pain in this species may be subtle. The unique challenges of feline metabolism and comorbidities may lead to undertreatment of pain and the development of peripheral and central sensitisation. Lack of availability or experience with various analgesic drugs may compromise effective pain management. Evidence base: These Guidelines have been created by a panel of experts and the International Society of Feline Medicine (ISFM) based on the available literature and the authors’ experience. They are aimed at general practitioners to assist in the assessment, prevention and management of acute pain in feline patients, and to provide a practical guide to selection and dosing of effective analgesic agents.

Serratus anterior plane block for cardiothoracic surgeries: a meta-analysis of randomized trials

Background Comparison of serratus anterior plane block to different analgesic methods for anterolateral thoracic wall incisions. Meta-analysis was used to address this concern. Authors systemically searched the MEDLINE, EMBASE, PubMed, and Cochrane databases to identify all published randomized and prospective clinical trials, comparing the SAPB with other methods that used for analgesia in different thoracic surgical procedures and trauma. Results Ten studies were identified for inclusion in this study, involving a total of 735 patients. Meta-analysis showed that, compared with thoracic wall analgesia and PCA methods, the SAPB group resulted in a significant decrease in pain scores, significant decrease in consumption of analgesic drugs, and a significant decrease in the incidence of nausea and vomiting with no difference in the rate of hypotension. Conclusions The use of SAPB in cardiothoracic surgery and trauma is a safe and effective option for thoracic analgesia.

The effectiveness and safety of paediatric prehospital pain management: a systematic review

Background Clinically meaningful pain reduction with respect to severity and the adverse events of drugs used in prehospital pain management for children are areas that have not received sufficient attention. The present systematic review therefore aims to perform a comprehensive search of databases to examine the preferable drugs for prehospital pain relief in paediatric patients with acute pain, irrespective of aetiology. Methods The systematic review includes studies from 2000 and up to 2020 that focus on children’s prehospital pain management. The study protocol is registered in PROSPERO with registration no. CRD42019126699. Pharmacological pain management using any type of analgesic drug and in all routes of administration was included. The main outcomes were (1) measurable pain reduction (effectiveness) and (2) no occurrence of any serious adverse events. Searches were conducted in PubMed, Medline, Embase, CINAHL, Epistemonikos and Cochrane library. Finally, the risk of bias was assessed using the Joanna Briggs Institute (JBI) checklist and a textual narrative analysis was performed due to the heterogeneity of the results. Results The present systematic review on the effectiveness and safety of analgesic drugs in prehospital pain relief in children identified a total of eight articles. Most of the articles reviewed identified analgesic drugs such as fentanyl (intranasal/IV), morphine (IV), methoxyflurane (inhalational) and ketamine (IV/IM). The effects of fentanyl, morphine and methoxyflurane were examined and all of the included analgesic drugs were evaluated as effective. Adverse events of fentanyl, methoxyflurane and ketamine were also reported, although none of these were considered serious. Conclusion The systematic review revealed that fentanyl, morphine, methoxyflurane and combination drugs are effective analgesic drugs for children in prehospital settings. No serious adverse events were reported following the administration of fentanyl, methoxyflurane and ketamine. Intranasal fentanyl and inhalational methoxyflurane seem to be the preferred drugs for children in pre-hospital settings due to their ease of administration, similar effect and safety profile when compared to other analgesic drugs. However, the level of evidence (LOE) in the included studies was only three or four, and further studies are therefore necessary.

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

Background Multimodal 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. Results Adverse 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. Conclusions Continuous 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.

The effect of transcutaneous electrical nerve stimulation (TENS) on pain control and phenylethanolamine-N-methyltransferase (PNMT) gene expression after cesarean section

Transcutaneous electrical nerve stimulation (TENS) is one of the non-pharmacological methods of pain relief that has been able to reduce pain by 70 to 90% in postoperative pain control. This study aimed to determine the effect of TENS on pain control after cesarean section and its effect on PNMT gene expression. For this purpose, a double-blind randomized clinical trial was performed on 70 Chinese patients with elective cesarean section. Patients were divided into case and control groups. In the case group, TENS and analgesic drugs were used to relieve pain, and in the control group, the only analgesic drug was used. Then the severity of pain, recurrence of pain attacks, the number of analgesic drugs used and the amount of analgesic drug used in the first 24 hours after surgery were evaluated and compared. Blood samples were also taken from patients to evaluate PNMT gene expression. The semi-quantitative RT-PCR was used to study changes in gene expression. The results showed that the group treated with TENS had less pain intensity and less recurrence of pain attacks than the group that received only analgesic medication. Also, the frequency of analgesic drug use and its dose in the TENS group were significantly lower than in the control group. TENS, on the other hand, has been able to greatly reduce the expression of the PNMT gene, which is produced during times of stress. Therefore, it is recommended that TENS be used as a non-invasive and non-pharmacological adjuvant effective in reducing pain after cesarean section.

Acute pain

This chapter discusses the management of acute pain. It begins with an introduction which describes the benefits of acute pain management and the measurement of pain. Analgesic drugs are then described, including paracetamol; non-steroidal anti-inflammatory drugs (NSAIDs), and opioids (including their comparative efficacy). Patient-controlled analgesia (PCA), epidural analgesia, and continuous peripheral nerve blockade are described. Transcutaneous electrical nerve stimulation (TENS) and acupuncture are discussed. The management of the patient with persistent pain and a substance misuse disorder is also discussed. The chapter concludes with a discussion of non-opioid adjuvant analgesics.

Metabolomic Studies for Metabolic Alterations Induced by Non-Steroidal Anti-Inflammatory Drugs: Mini Review

Non-steroidal anti-inflammatory drugs (NSAIDs) are Food and Drug Administration (FDA) approved antipyretic, anti-inflammatory, and analgesic drugs to mitigate pain, however it is associated with gastrointestinal injury and cardiovascular disease in some individuals. Metabolomics has the potential to understand the interaction of host and the drugs, such as NSAIDs administration. This discipline has been used by many researchers to understand the serious side effects of NSAIDs. We highlighted (1) the potential of metabolomics in understanding the pathogenesis of adverse events due to NSAIDs administration; (2) choice of metabolomics techniques, bio sample handling; (3) review of metabolomics studies in the front of NSAIDs in different biofluids and tissues; (4) pathway analysis of the data presented in the published literature. In our analysis we find tricarboxylic acid cycle (TCA), “glycine serine and threonine metabolism,” “alanine, aspartate, and glutamate metabolism,” and fatty acid metabolism to be altered by the NSAIDs like ibuprofen, indomethacin, naproxen, aspirin, and celecoxib. In conclusion, metabolomics allows the use of biological samples to identify useful pathways involved in disease progression, and subsequently inform a greater understanding of the disease pathogenesis. A further in-depth investigation of the associated pathways mentioned above holds the potential for drug targets for side effects mitigation.