{"id":916,"date":"2016-03-01T11:07:36","date_gmt":"2016-03-01T16:07:36","guid":{"rendered":"http:\/\/phosdev.com\/todaysveterinarynurse\/?post_type=articles&p=916"},"modified":"2022-06-20T18:22:45","modified_gmt":"2022-06-20T18:22:45","slug":"pain-recognition-and-management-in-critical-care-patients","status":"publish","type":"post","link":"https:\/\/navc.sitepreview.app\/todaysveterinarynurse.com\/emergency-medicine-critical-care\/pain-recognition-and-management-in-critical-care-patients\/","title":{"rendered":"Pain Recognition and Management in Critical Care Patients"},"content":{"rendered":"

Pain management is crucial in critical care patients. Pain has multiple negative effects that can delay or prevent healing, and veterinary technicians play a central role in pain management. Understanding pain, its consequences, and how it can be addressed increases veterinary technicians\u2019 ability to work with veterinarians to ensure that patients are comfortable both during hospitalization and when they go home.<\/p>\n

Physiology of Pain<\/h2>\n

Nociceptors are unmyelinated peripheral neurons sensitive to noxious stimuli. They are found throughout the body and are triggered by mechanical, chemical, or thermal stimuli.1<\/sup><\/p>\n

When a stimulus activates a nociceptor, a nerve impulse is produced. This impulse is transmitted to the dorsal horn of the spinal cord, where it causes the release of neurotransmitters (e.g., aspartate, glutamate \u03b3-aminobutyric acid [GABA]) and neuropeptides (substance P). Some of these are excitatory and continue to send the signal up the spinal cord to the brain, while others are inhibitory and inhibit the signal from traveling further. Inflammation causes an increase in excitatory neurotransmitters while reducing inhibitory neurotransmitters.2<\/sup><\/p>\n

There are three types of nerve fibers: A-delta, A-beta, and C fibers. A-delta fibers are medium to small, thinly myelinated, and conduct at a speed of 6 to 30 m\/sec. A-beta fibers are larger, myelinated, and conduct at a speed of 30 to 70 m\/sec. C fibers are small, unmyelinated, and conduct at a speed of 0.5 to 2 m\/sec.1 A fibers are sensitive to thermal or mechanical stimulation, causing a sharp, localized pain, while C fibers can be sensitive to thermal, mechanical, or chemical stimuli, causing a dull, aching pain that is more diffuse.1,3<\/sup><\/p>\n

Pathophysiology of Pain<\/h2>\n

Pain, whether from injury or surgery, can have many detrimental effects if left untreated. The release of catecholamines in response to a painful stimulus results in tachycardia, hypertension, and an increase in oxygen consumption by the myocardium. If prolonged, this can lead to left ventricular dysfunction, ischemia, and possible infarction. An increase in the release of cortisol and glucagon can cause insulin resistance and hyperglycemia. Stress caused by pain increases the activity of clotting factors, leading to an increased risk for developing a coagulopathy. Stress also suppresses the immune system, leading to an increased risk for infection.4<\/sup><\/p>\n

If thoracic pain is present, the patient may be unwilling to breathe normally, leading to atelectasis. Decreased gastrointestinal motility and the development of ileus and urine retention after abdominal surgery (secondary to pain and an unwillingness to posture to urinate) can cause decreased bladder function. The patient may also be anxious, agitated, and unable to rest, prolonging the recovery period.4<\/sup><\/p>\n

Recognition of Pain<\/h2>\n

Recognition of pain has always been difficult in veterinary patients. Some patients are stoic and do not demonstrate obvious signs of pain, while others are very sensitive and will react to the slightest touch. The patient may be hunched, splint (stiffen its muscles) with abdominal palpation, vocalize (growl, hiss), refuse to lie down, stretch (FIGURE 1)<\/strong>, be restless or agitated, be tachycardic or hypertensive, refuse to rise, or walk stiffly. If measures taken to relieve pain seem unsuccessful, it is helpful to ask the owner about the patient\u2019s normal behavior and attitude.<\/p>\n

\"FIGURE<\/a>

FIGURE 1.<\/strong> This type of stretch, called prayer posture, can be a sign of pain. This dog presented for vomiting. He was later taken to surgery and underwent foreign body removal.<\/p><\/div>\n

While pain management is a team effort, the veterinary technician plays a large role in recognition and treatment of pain. The patient should be assessed at the beginning of the shift so that any changes can be noted throughout the day.<\/p>\n

Pain Versus Anxiety<\/h3>\n

It is important to be able to distinguish between pain and anxiety because both can cause tachycardia, hypertension, and changes in posture. Removing the patient from its kennel or taking it out for a short walk may alleviate some anxiety. If an outside area is available, it is often advantageous to assess the patient outdoors to see if it is more relaxed out of the hospital environment.<\/p>\n

Patient comfort while in the kennel is equally important to reducing anxiety; however, individual preferences vary. A soft, thick bed can keep older patients more comfortable, while other patients prefer a thin blanket and refuse to lie down if the bed is too thick or soft. Cats often prefer a bed, although occasionally they prefer to lie in the litterbox. Cats that will not use a standard bed may be happier with a blanket placed in a second litterbox or no bed at all.<\/p>\n

Some canine breeds are normally vocal (e.g., beagles, Northern breeds). Veterinary technicians should be able to differentiate between normal vocalization and vocalization secondary to pain or discomfort.<\/p>\n

Assessing Pain<\/h3>\n

Gentle palpation of the abdomen can reveal abdominal pain. Some patients become tense immediately on being touched, and it is helpful to place your hands on either side of the abdomen, wait for the patient to relax, and then slowly palpate the abdomen. If the patient tenses, leave your hands where they are until the animal relaxes again; then continue palpating. If the patient does not relax or is vocal, pain is likely present, and the veterinarian should be notified.<\/p>\n

If the patient is tachycardic when auscultated, it is advantageous to leave the stethoscope in place for a minute or two to give the patient a chance to relax and the heart rate to normalize. Pain is only one cause of tachycardia and other causes (e.g., hypovolemia, anxiety, excitement) should be ruled out.<\/p>\n

Painful patients are reluctant to move and often refuse to lie down or stand up because they anticipate pain associated with changing position (FIGURE 2)<\/strong>. If a patient does not appear painful but refuses to lie down, it may be anticipating pain. It is often helpful to physically lay the patient down and sit with it until it has relaxed.<\/p>\n

\"FIGURE<\/a>

FIGURE 2.<\/strong> This dog was admitted to the hospital after being hit by a car. He is showing signs of pain, including refusing to lie down, panting, and an anxious expression. After receiving a bolus of fentanyl, he lay down and slept for several hours.<\/p><\/div>\n

Pain scales can be used to ensure pain assessment remains consistent. Colorado State University has developed pain scales for dogs and cats that assess behavior as well as response to environment and palpation (see CLINIC RESOURCES<\/strong><\/a> page).<\/p>\n

Cats<\/h3>\n

Cats are often difficult to assess. They may be fractious by nature, and so hissing or growling may not indicate pain. Tachycardia and increased respiratory rate may be signs of anxiety rather than pain, and hiding, while a possible sign of pain, can also be caused by simple fear. To decrease stimuli that may contribute to fear and anxiety, covering the cage with a blanket may be beneficial. If possible, keeping feline patients in quieter surroundings (e.g., away from noisy dogs) may also help.<\/p>\n

A painful cat may be quiet while refusing to move or may become aggressive and growl or hiss while rolling in its kennel.5<\/sup> It is worthwhile to try observing the cat from a distance in case your presence causes anxiety. When palpating for pain, it is recommended to palpate the area several times and watch for a repeatable pain response. If you are unsure whether the patient is painful, it is always best to assume that it is and administer analgesics.<\/p>\n

Team Communication<\/h3>\n

If the veterinary technician believes a patient is in pain, he or she should approach the clinician to discuss additional pain management. It is in the patient\u2019s best interest to obtain as much information as possible before going to the clinician with concerns (BOX 1)<\/strong>. When talking to the clinician, technicians should be ready to discuss observed signs of pain, what has been done to address other possible causes of discomfort (e.g., walking the patient, checking the bedding, ensuring the intravenous catheter is patent), and what analgesics the patient is receiving, including the dose, frequency, and time of last administration.<\/p>\n

BOX 1<\/strong> Pain Assessment Checklist<\/div>
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