Congress on Demand 2021: Anaesthesia and Analgesia

Acupuncture is now established as a physical therapy which interacts which the patient’s body and brain in ways that can be demonstrated experimentally and clinically. Acupuncture has effects locally, segmentally, heterosegmentally and generally (humeral and brain effects). The main brain effect of manual acupuncture (i.e. without electrical stimulation of the needles) is on the limbic system, which is the main system influencing emotion. This is one explanation of why owners of animals who have received acupuncture often describe them as "happier" and perhaps "picking up a toy for the first time in ages”. Acupuncture makes the patient feel better about the problem from which it is suffering; they are less concerned about the pain and, therefore, stress and suffering are reduced. This is not all acupuncture does, but it is an important effect and should be evaluated in clinical studies and in clinical practice. Acupuncture is not a difficult technique to learn. The skill comes in examining the patient for the ‘targets’ of acupuncture; deciding whether to use needles; where to put them; which needles to use; and what to do with them once inserted. The techniques learned enhance the chronic pain examination and are rewarding for patient, owner and clinician.

Drug free management: Owners must understand that medical analgesia is often vital to reduce suffering, especially at the start of the treatment of chronic pain. We cannot, by explaining that chronic and acute pain are distinguishable by the threat they pose to survival, teach our animal patients to be to be unafraid of their pain. We therefore need to reduce both the sensation and the emotion of pain and this process sometimes needs medication. Where the pain field has become exaggerated and expanded, physical therapies may be contraindicated until that field has been reduced. Rather than ‘drug free’ (which tends to give ‘drug use’ a negative sense), the physical therapies should be thought of as integrated; relatively safe; and relatively free of side effects. Their use may reduce the use of medicines; may positively contribute to the animal’s health and mobility; and, often, indirectly contribute to owner compliance because the therapist can continue to educate and to build on the plan. Physical therapies include but are not limited to: acupuncture; physiotherapy and hydrotherapy; laser; manipulation; and myotherapies of various kinds. This lecture will briefly describe the most common therapies, their indications, advantages and possible drawbacks.

Foundations of drug therapy – building the plan and an overview of NSAIDs: Medical treatments provide the cornerstone of most pain management plans, but how effective are they in addressing chronic pain? Osteoarthritis is a major cause of chronic pain and it is an excellent example of the need to properly understand how pain is being generated before attempting to resolve it. Management involves controlling the local disease, a source of nociceptive stimulation, while at the same time separately addressing non-nociceptive mechanisms, neuropathy and central processing. NSAIDs have been used widely and successfully to address pain in OA. We almost know too much about these drugs and our knowledge restricts our use and client acceptance due to risk of toxicity. However, there are other limitations in managing chronic pain using NSAIDs. The use of unlicensed medications to treat chronic pain about has increased greatly. But are they safe or effective? Properties do not easily translate between species as we found in the past with NSAIDs and more recently with tramadol. Medical agents are important tools in building a management plan but due consideration must be given to therapeutic targets, effectiveness, duration of use, practicality and common sense.

Is it cold in here? Hypothermia under anaesthesia: Hypothermia is one of the most common complications that occur during anaesthesia. This session explores why hypothermia occurs; why do we need to worry about hypothermia – what are the negative effects?; prevention is better than cure!; heat loss is more likely to occur during certain periods during the patients anaesthetic journey – when are these and what are the most suitable strategies to combat this heat loss during these different periods?; the evidence behind some patient warming modalities; the importance of safety and the prevention of patient harm from warming devices – what strategies can be used to prevent these events?; what techniques are available to monitor temperature? The aim is to provide practical hints and tips that can be translated into day to day clinical practise.

Get the suction! Regurgitation under anaesthesia: Why do patients regurgitate during anaesthesia? How do we recognise that a patient has regurgitated? And what should we do when it happens? This session reviews reflux and regurgitation during anaesthesia in dogs and cats, exploring the literature to enable us to best focus our management of this situation. Reflux and regurgitation are common anaesthetic complications, requiring recognition and treatment to reduce the risk of unwanted sequelae. The number of cases of sequelae reported is low, but the development of an oesophageal or nasopharyngeal stricture, or oesophagitis can prolong hospitalisation and increase patient morbidity. What is the best approach to managing this complication – is suctioning the oesophagus alone enough, or should we be flushing with water/saline and administering any medications? What signs can we look out for to warn us that a patient has regurgitated, when is it most likely to happen and are there any risk factors we should be aware of? Finally, the session explores whether any preventative or prophylactic measures can be helpful, and what, if any treatments to consider for at risk patients or for a particular procedure with an increased risk.

How capnography can help you identify problems with your patient: Capnography is arguably the most reliable and least error prone anaesthetic monitoring modality available, and it can contribute significantly to patient safety. Capnography relies on the measurement of inspired and expired carbon dioxide and primarily gives information about respiratory adequacy. Distinctive capnograph trace patterns can also alert the user to breathing system faults, endotracheal tube problems and acute lung pathology. Additionally, capnography is recommended to prognosticate and judge the effectiveness of chest compressions during CPR. This session discusses an approach to using and interpreting the capnograph to diagnose problems under anaesthesia.

What options you have in managing hypotension under anaesthesia if fluids don’t work: This session presents an update on recent advances and controversies in managing hypotension during general anaesthesia. Hypotension is one of the most common adverse effects of general anaesthesia. Options for managing anaesthetic-induced hypotension include: 1. reducing the inhaled anaesthetic requirement: this can be achieved directly or indirectly (e.g. by providing analgesia). 2. fluid administration: the efficacy and duration of crystalloid fluid boluses are limited but a number of tools are available to identify patients that will benefit from a fluid bolus (e.g. pulse pressure variation) 3. vasoactive agents (e.g. dexmedetomidine, dopamine, ephedrine): there are pros and cons to the different agents available. These options and practical approaches are discussed.

This lecture covers the basic anatomy we need to know to choose the right loco-regional technique and shows easy techniques that can provide good analgesia for celiotomy.

Although regarded as a routine operation, neutering is probably the most invasive procedure undertaken in the majority of pets in the UK. Anaesthesia should be tailored to each patient to ensure not only anaesthesia adequate depth for the operation, but also to ensure preservation of normal physiology as well as excellent analgesia. This session explores the possible approaches that could be applied in practice. It examines the importance of a thorough clinical examination, benefits of tailored premedication, and outlines best practice in anaesthetic induction, maintenance and recovery. Finally, examples are given of how the approach could be modified when dealing with commonly encountered breed specific and clinical problems.

Safe sedation and sedation versus anaesthesia: when is it ok to not intubate?: When is it ok to use sedation safely and not induce anaesthesia? Are there any circumstances where anaesthesia should be chosen? This session reviews options for sedation and explores factors, both with regard to the patient and the procedure, that will enable best practice. Most diagnostic and minor procedures require our patients to be sufficiently immobilised to allow for good patient safety and a successful procedure. In the healthy patient the use of sedation for most procedures will have little, if any impact on the animal. What about those more challenging cases – the aggressive or fearful cat, the geriatric patient with multiple comorbidities, or the cardiac case requiring a prolonged procedure. A question useful to ask is, can we safely give sufficient sedation to allow the procedure to be completed successfully and for the patient and veterinary team to be stress free? If the answer to this is yes, then sedation is most likely to be sufficient. What if it’s not? Finally, we explore options for providing good sedation in a number of case examples.

Monitoring for sedation: The importance of monitoring of patients during sedation is often underestimated. During the session we explore: why is close monitoring of these patients is so important?; the importance of an understanding of the agents used to sedate the patient and how these effect the monitoring picture; what should be monitored during sedation?; how can we maximise patient safety?; tailoring your monitoring techniques for different patients – practical hints, tricks and tips; techniques to maximise the effectiveness of monitoring devices – how to check they are accurate?; when sedation goes wrong – the early warning signs that the patient may not be coping and what to do; the recovery period – the forgotten period!

Establishing pain through owner questioning: Where to start can depend on whether the consultation was booked to specifically discuss pain or whether pain was detected as part of a routine examination. Validated pain scores are an essential resource to provide a structure to owner questioning. For the planned consultation these can be emailed to the owner prior to the consultation or where pain is noted in a routine consultation can be given to the owner for completion after the consultation. Pain scores are really useful not only for providing a baseline prior to initiating treatment, but as a basis for discussion and further history taking. I find they stimulate owners to mention additional information that can be useful. Options to consider are: Canine Brief Pain Inventory (CBPI); Liverpool Osteoarthritis in Dogs (LOAD); Helsinki Chronic Pain Index (HCPI); Feline Musculoskeletal Pain Index (FMPI); Vetmetrica Health Related Quality of Life System. During history taking I aim to establish 3-5 pain behaviours to use as a baseline. These may be new behaviours associated with pain or behaviours that the pet doesn’t do anymore where the change could be attributed to pain. This introductory session covers the different attributes of these pain scoring systems and when you may choose one over another.

What can be achieved in a 10 minute consult? Chronic pain takes time to develop and will take time to resolve or manage, therefore the first thing to emphasise to the client is that this initial consultation (or from wherever the clinician is picking up the case) is just that: initial, and that there will be a plan to progress the treatment. The first consultation should identify the owner’s concerns; try to establish the sources and classifications of pain present; identify some clear, initial outcome measures; and begin the process of reducing the patient’s suffering. Owner concerns include: their pet’s suffering; inability to exercise; withdrawal and reduced interaction (especially cats); unwanted changes in behaviour (including toileting irregularities; restlessness at night; fearful behaviours); possible side effects of medication; absence of a firm diagnosis; and a potential misunderstanding of what can be achieved with chronic pain problems (i.e. management versus cure). The clinician should observe movement, gait and postural abnormalities. The examination should be performed on as relaxed a patient as possible; aim to establish the presence or absence of secondary sensitisation; and minimise pain and fear. From the history and the examination, the sources and classification of pain may be established; the clinician should aim to identify at least one sign of suffering and/or physical outcome measure, start on appropriate analgesia and arrange a review.