Rough Recoveries
When a balanced anesthesia drug protocol has been utilized most of our patients will wake up smoothly from general anesthesia. Unfortunately, despite our best efforts, there will be times when a patient wakes up and displays a rough recovery. Rough recoveries are often characterized by the patient displaying behaviors such as excessive vocalization, paddling their legs, head bobbing or head thrashing, agitation (constantly attempting to move around) and disorientation.
The three most likely causes of a rough recovery are pain, emergence delirium and dysphoria.
The patient's temperament and anxiety level while in the hospital may also influence how the patient recovers from general anesthesia. It can be difficult to predict when a particular patient will have a rough recovery so having a plan to manage rough recoveries is recommended for every patient. History tends to repeat itself. If a patient was anesthetized in the past and had a rough recovery, chances are they will have a rough recovery the next time they are anesthetized. Also, if the patient has a rough induction there is a good chance that they will have a rough recovery as well. Before the inhalant is turned off, the anesthetist should evaluate the anesthesia record to determine the time that analgesic and sedative drugs were given in the premedications and if/when additional doses were administered during the procedure. If the duration of action of the analgesic and sedative agent has been exceeded, then additional doses should be available during recovery.
Because our patients cannot verbally communicate with us it is often difficult to determine if a rough recovery is due to pain or emergence delirium or anxiety. Therefore, it is better to treat with an analgesic drug (pure agonist opioid) and sedative agent together rather than give either drug alone. A tranquilizer agent such as acepromazine will cause sedation but it will not adequately address the painful state when given alone because it does not have any analgesic properties. Dexmedetomidine is superior to acepromazine because it also provides analgesia in addition to its sedative effects. An example of a treatment protocol for a rough recovery would be to administer a pure agonist opioid such as hydromorphone IV combined with microdosages of either acepromazine (0.01 mg/kg) IV or dexmedetomidine (1-2 mcg/kg) IV providing no contraindications exist for the sedative agent.
Microdosages of the sedative agent are usually sufficient enough to calm a patient that is having a rough recovery, so it is not necessary to use the dosages commonly used for premedication.
A painful patient will generally relax and stop vocalizing after an analgesic agent has been administered. They also are responsive to human interaction so it helps to talk calmly to them while providing gentle restraint. If the anesthetist suspects that the rough recovery was due to pain it is a reasonable option to just give the pure agonist opioid alone and wait 3-5 minutes to evaluate the effects of the drug on the patient. If there are no contraindications, microdosages of dexmedetomidine can be added if the opioid does not appear to be enough.
Emergence delirium is defined as a dissociated state of consciousness in which the patient is unaware of their surroundings. Patients can display excitement, agitation, restlessness and vocalization. In pediatric human patients, emergence delirium has been shown to occur with just about every anesthetic agent, including the inhalants. In veterinary medicine, emergence delirium is more likely to occur when there is no sedative agent on board during the recovery period. If dexmedetomidine was administered as a premedication and more than 2-3 hours have elapsed before recovery, there is a good chance that the patient will display emergence delirium behavior. The term is also used to describe the behavior seen when ketamine is the only agent on board during recovery and is more likely to be seen in cats than dogs. Dogs tend to have rough recoveries when given tiletamine/zolazepam because the zolazepam has a shorter duration of action than the tiletamine. These patients are usually treated with a combination of opioids and sedative agents so that both analgesia and sedation are addressed. In humans, other conditions that may result in disorientation and altered mental status in the recovery period include hypoxia, severe hypercapnia, hypotension, hypoglycemia, increased intracranial pressure and distended bladder. All of these conditions can occur in animals, so it is reasonable to consider them as causes for emergence delirium in animals as well. Appropriate monitoring of the patient should detect most of these conditions and prompt treatment is required if present. As long as there are no contraindications, expressing the bladder before a patient recovers can help rule out this source of a rough recovery.
Unfortunately, there are no clearly defined lines of where a patient is classified as experiencing emergence delirium verses when they are anxious. Emergence delirium usually occurs immediately after extubation when the patient regains consciousness, but it can be used to describe adverse behavior for a few hours after extubation as well. Once a patient is fully conscious, it is usually term anxiety. Like pain, anxious patients tend to calm down and stop being vocal when we interact with them.
If emergence delirium is suspected to be a cause of a rough recovery immediately after extubation then sedative agents (acepromazine or dexmedetomidine) should be administered IV. The sedative is usually given in combination with an opioid to rule out pain. If it is several hours out from recovery and pain has been addressed, then oral calming agents such as trazodone can be used. Sileo® (dexmedetomidine gel), gabapentin and pregabalin are also options that can be used as calming agents.
Dysphoria has been described as a profound state of unease or dissatisfaction accompanied by anxiety or agitation. In dogs, it has been described as causing agitation, excitement, restlessness, excessive vocalization and disorientation. Dysphoria in cats has been described as causing hallucinatory behavior, open-mouth breathing, agitation, vocalization and pacing. When classifying a rough recovery the term 'dysphoria' is often inappropriately used to describe the behavior.
Just because a patient is vocalizing in recovery does NOT mean the patient is dysphoric.
As you can see, the words used to describe dysphoria can also be used to describe emergence delirium and pain in recovery. From an anesthesia standpoint, dysphoria is often associated with administering excessively high dosages of opioids to patients' not experiencing a painful condition. It is usually associated with pure agonist opioids, but the other opioid drug classes (e.g., partial agonists, agonists/antagonists) can also result in dysphoria.
Although it can be difficult to determine if a patient is painful verses dysphoric there are some key differences with how a patient responds to treatment. The source of the pain is often difficult to identify in a truly dysphoric patient whereas it is easily identified in a painful patient. Unlike a painful patient, a dysphoric patient is unresponsive to human interaction. They will not respond to being talked to and will continue to be vocal and agitated even when properly restrained. Administering an analgesic agent (opioid) will either do nothing or make the condition worse. If a patient does not respond to the administration of an opioid, the patency of the catheter should be checked first to ensure that the drugs actually went IV.
Administering a sedative agent is the treatment of choice for a dysphoric patient and should be given concurrently with the opioid. If dysphoria is determined to be the cause of the rough recovery, then a sedative such as demedetomidine may need to be administered as a continuous rate infusion in order for the patient to be comfortable in the recovery period. Another option for treatment of dysphoria is partial reversal with butorphanol. Butorphanol will antagonize the mu receptor and will reverse the sedative and analgesic effects associated with the mu receptor but will still provide some analgesia due to the kappa agonist activity. This is called sequential analgesia. Partial reversal with butorphanol is a viable option for treatment if sedative agents are contraindicated but it might not provide enough analgesia to address pain associated with a surgical procedure. Other means of analgesia should be implemented before using butorphanol as a treatment for dysphoria. Complete reversal of the opioid with naloxone should only be considered in the event of an opioid overdose. It should not be used as a treatment for dysphoria unless all other treatment options have been attempted and were unsuccessful. In non-verbal patients, titrating naloxone for "partial reversal" should be used cautiously. The potential for full reversal is always a possibility even when titrating the drug. Acute awareness of pain can lead to catecholamine surges that result in death.
When dogs are administered opioids alone, they usually respond with some degree of sedation regardless if they are painful or not. However, some breeds of dog such as arctic breeds (e.g., Husky, Malamute, Akita, etc.) tend to display behavior that is commonly termed dysphoria after the administration of pure agonist opioids. These breeds tend to be very vocal in recovery no matter what procedure was performed but that does not necessarily mean they are dysphoric or adversely responding to the opioid. It is important to provide these patients with appropriate sedatives in combination with opioids to help smooth out the recovery period. Opioids are not contraindicated in these breeds simply because of this tendency to respond in this manner.
Cats tend to show excitement or euphoria when opioids are used alone in non-painful patients. They tend to display behavior such as rolling around, excessive kneading of an object with their paws and extreme friendliness. Adverse behavior associated with excitement such as agitation and restlessness can be treated with sedative agents. Not all cats will respond with an excited reaction when given an opioid alone. In fact, some might not even respond at all and appear completely normal as if they were not administered any opioid.