Image courtesy Stacey Reiling
Regurgitation is a potential complication in anesthetized small animal patients.1 A patient regurgitating under anesthesia can lead to more detrimental complications, such as aspiration pneumonia, rhinitis, and esophagitis, which can lead to strictures. All of these complications from regurgitation can vary from mild irritation to severe and can become potentially life threatening.
There are many conditions that may predispose a patient to be more likely to regurgitate under anesthesia. The goal of this article is to give some ideas of what we could do to prevent regurgitation in these higher risk patients, as well as what to do if regurgitation under anesthesia occurs.
In the case where there is a patient coming in with a known history that may predispose them to regurgitation or make them high risk for regurgitation, such as megaesophagus, there are some medications we can administer at home prior to them coming into the hospital, as well as throughout the anesthetic event.
These cases also sometimes regurgitate for days after the anesthetic event, and so some of the medications could be continued at home. In the case of a GI obstruction, some of the medications may be contraindicated. In these cases, surgical intervention usually will fix the cause of the regurgitation and so they might be less likely to do so afterward, in these cases it is best to prepare for the event to happen to address it as soon as possible.
Pre-anesthesia medications for vomiting and regurgitating patients2
Antiemetic/neurokinin-1 antagonist to prevent vomiting can be given prior to the anesthetic event and for a few days after for some of the higher-risk patients.
Histamine type-2 receptor antagonist and/or a proton pump inhibitor can decrease the incident of esophagitis and rhinitis in the case where regurgitation occurs. This can be given post-operative a few days prior to the anesthetic event, and can be given a few days after it for those higher-risk patients.
Prokinetic/motility modifier agent can be used in some of these patients; it is contraindicated in patients with GI obstruction. In patients who are high risk without a GI obstruction this can be used for a few days prior to, and also a few days after, the anesthetic event.
Tailored anesthesia protocols are important for each patient. (Author's note: Thorough pre-anesthetic assessment is key to make an individualized plan to achieve the best outcome. I do not want to go into anesthesia protocols for this article, other than to state avoidance of agents that may exacerbate or cause vomiting or regurgitation.)
Steps to decrease further complications
Prior to induction, have your equipment within reach and ready to go. Just like any anesthesia induction, have the anesthesia machine leak-tested and ready to go with the appropriate size bag and hoses. Endotracheal tubes should have been checked for leaks, the cuffs deflated, and sterile lubrication open and ready to go. A laryngoscopes should be handy, a tube tie of your choice should be handy, and your monitor and equipment should be on your patient.
In addition, have suction available for high-risk patients, as well as suction tubing, suction catheters, and either a long, red rubber catheters or Salem sump-type GI tube. An appropriate- sized endogastric tube with a bucket in the case of a stomach filled with fluid, should also be on hand.
I recommend a rapid sequence induction for these patients. There should be pre-oxygenation with monitoring already attached to the patient prior to induction. Induction agents of choice should be given in order to decrease any excitement or further delay to the integration process with smooth transition from one agent to another. The patient should be rapidly intubated with a pre-selected lubricated tube and the airway secured. Once the airway is secured and the patient is stable, the airway can be reassessed.
If the patient regurgitates during this induction process, the head should be dropped lower than the patient's body so the fluid leaks out of the mouth and is not inhaled. Suction should be done as soon as possible. Ideally, the patient should be intubated and airway secured so suction can be done in a more controlled manner; however, ideal does not always happen. Sometimes the patient needs to be suctioned while being intubated with the patient's head held lower than the body to allow the liquid to fall from the mouth.
Once the patient is intubated, and airway secured, the mouth, esophagus, and nasal passages all should be suctioned and flushed with either saline or water. The Salem sump is a very useful tube for achieving this as it can go down the esophagus, sometimes directly into the stomach, for suctioning as well as having an attachment for flushing.
Flushing is often an overlooked step in the process; however, flushing away the regurgitant from the mucous membranes can decrease irritation and thus decrease the severity of incident of rhinitis and esophagitis and prevent strictures. Checking the patient often is an essential part for preventing further complication. Suction and flushing should be done as needed throughout the anesthetic event; checking that the airway is secure each time.
At the end of the anesthetic procedures, the patient is evaluated and checked again for any evidence of further regurgitation. The patient is extubated in a sternal position with the head angled in a way that the fluid can leak out of the mouth. Ensure the patient has a good swallow reflex so if it is to regurgitate after extubation, it is awake enough to swallow versus inhaling the regurgitant. The tube cuff can also be slightly inflated with the goal to "squeegee" any fluid that has gone down the trachea, back up with the tube.3
As regurgitation is a common complication to general anesthesia and the agents that we deliver to these patients, it also is a condition, which we can treat and try to prevent further insult. We can't often predict which patients are going to develop this problem, but we can be prepared and react in an appropriate manner to prevent further complication.
Stacey Reiling CVT, VTS (anesthesia/analgesia), CVP, graduated from Harcum College in 2000 with an Associates of Science in Veterinary Technology degree. She became a certified veterinary technician in 2000, and worked as a veterinary anesthesia technician at the Matthew J. Ryan Veterinary Hospital of the University of Pennsylvania. Reiling obtained her specialty in Anesthesia/Analgesia in 2005. She left academia and joined a small animal specialty referral and emergency and became a certified veterinary pain practitioner in 2015. Reiling has interest in anesthesia in pain management for both surgical and nonsurgical, domestic and nondomestic patients, as well as a special interest in the mechanics of anesthesia machines and monitors. She has delivered many RACE-approved presentations for veterinary technicians
and veterinarians.
References
1 Veterinary Anesthesia and Analgesia, The fifth Edition of Lumb and Jones; Kurt A. Grimm, Leigh A Lamont, William J Tranquillity, Stephen A. Greene, Sheila A. Robertson; Section 1: General Topics, Chapter 2: Anesthetic Risk and Informed Consent, P. 14. 2015
2 Blackwell's Five minute Veterinary Consult: Canine and Feline Sixth Edition; Larry P. Tilley, Francis W.K. Smith, Jr; Vomiting, Acute; P. 1400. 2017
3 Veterinary Anesthesia and Analgesia, The fifth Edition of Lumb and Jones; Kurt A. Grimm, Leigh A Lamont, William J Tranquillity, Stephen A. Greene, Sheila A. Robertson; Section 8: Gastrointestinal and Endocrine Systems; Chapter 31: Physiology, Pathophysiology, and Anesthetic Management of Patients with Gastrointestinal and Endocrine Disease: P661 2015
