A dedicated anesthetist should be assigned to monitor every patient during the perianesthetic period. The anesthetist is fundamental to patient safety because she assures the patient is not aware, not moving, and not in pain, all while maintaining stable anesthetic depth. A deep plane of anesthesia can lead to hypoventilation and hypoxemia, reduced cardiac output, hypotension, inadequate tissue perfusion, central nervous system (CNS) depression, and prolonged recovery. This review article first explores the stages of anesthesia and then discusses assessment of anesthetic depth in exotic companion mammals, birds, and reptiles.
Upon completion of this RACE-approved learning aid, the participant will have a basic clinical understanding of anesthetic monitoring of exotic animal patients: birds, exotic companion mammals, and reptiles.
Capnometry measures the maximum value of carbon dioxide (CO2) obtained at the end of expiration or end-tidal carbon dioxide (ETCO2). There is good correlation between ETCO2 and arterial CO2 in birds and mammals and capnography can be used as a reliable tool to evaluate the adequacy of ventilation in these species. Capnography can only be used to identify trends in reptiles because of cardiac shunting of blood past the reptilian lungs.
Even the most steadfast and seasoned veterinary anesthetist can find themselves intimidated by exotic animal patients. Standard veterinary anesthesia monitors are not designed to read the extremely high (or extremely low) heart rates and respiratory rates of some exotic animal patients. Despite these challenges, valuable information can be gathered from monitoring tools as well as hands-on techniques. Essential vital signs, such as heart rate and rhythm, respiratory rate and depth, body temperature, and mucous membrane color should all be evaluated.
Arterial blood pressure is a function of heart rate, blood volume, stroke volume, and arterial compliance. Indirect arterial blood pressure is most commonly measured by Doppler ultrasound or non-invasive oscillometric monitors. What are the limitations of indirect blood pressure measurements in exotic animal patients? How is this technique unique in exotic companion mammals when compared to dogs and cats? How is this technique performed in birds and can this procedure be used in reptiles?
Electrocardiography can be used to detect and diagnose arrhythmias and conduction abnormalities, particularly during long-term anesthesia. How are leads attached to exotic animal patients? And what is the normal appearance of normal electrocardiogram tracings in birds or reptiles?
Heart rate and oxygenation should ideally be monitored during every anesthetic event. Patient size can limit the accuracy of pulse oximetry readings in exotic companion mammals and this technique has not been validated in birds or reptiles, however trends during the course of anesthesia can still provide useful clues to patient clinical status.
Created by veterinary technician specialist, Katrina Lafferty, this anesthesia monitoring record is available for download as as both a Word document and PDF.
Download this anesthetic record, available as a PDF, and recommended by veterinary technician specialist, Katrina Lafferty.
Download this anesthesia & recovery record, suggested by veterinary technician specialist, Katrina Lafferty. This anesthetic record was created by the Association of Veterinary Anaesthetists and is from a collection of online resources recommended by the Royal College of Veterinary Surgeons Practice Standards Scheme.
Download this anesthesia monitoring sheet, available as a PDF, and recommended by veterinary technician specialist, Katrina Lafferty.
Guinea pigs are small, docile rodents, that must be approached with great care. Accurate evaluation of patient health status requires a thorough history, careful visual examination, and a detailed physical examination. Like most prey species, the guinea pig frequently hides signs of pain and illness. To improve clinical success, take measures to minimize stress by maintaining the animal in a quiet exam room and approaching the patient in a slow, quiet manner. The hospitalized guinea pig can also benefit greatly from the presence of a bonded cage mate. Monitor appetite and eliminations carefully in the guinea pig, and offer the same diet as fed in the patient’s home whenever possible as guinea pigs establish strong food preferences early in life.
Diagnostic and therapeutic procedures cannot be administered until you and your staff can safely handle and restrain the lizard patient. This article reviews patient transport and defense mechanisms of the lizard, including tail autotomy, as well as protective gear and restraint techniques.
The approach to analgesia and sedation in exotic companion mammals faces special challenges, including small patient size and unique features of the prey species mentality. Recognition of pain is more difficult in rabbits and rodents because many small mammals are very good at hiding the signs of pain commonly observed in predator species. Instead pain in a rabbit or rodent is often inferred from the patient’s clinical condition as well as the absence of normal behaviors. The diagnostic and therapeutic plan frequently requires some form of chemical restraint in exotic mammal medicine. When compared to general anesthesia, sedation is a safer option for the debilitated or critically ill small mammal.
Exotic small mammals can be challenging to safely induce, maintain and recover from general anesthesia. View the recording of this AAVSB R.A.C.E.-approved webinar, which explores clinical anesthesia in exotic companion mammals from patient assessment and anesthetic induction to monitoring and recovery. The use of common premedications, induction agents, maintenance drugs, and post-operative analgesics will be compared and contrasted in exotic companion mammals. Multimodal anesthetic techniques, such as epidural anesthesia and constant rate infusions, will also be discussed. After reviewing the recording, take the brief post-test to earn 1 hour of continuing education credit.
Due to their unique anatomy, physiology, and behavior, critically ill reptiles pose special challenges. Fortunately there are a host of tips and tricks that can increase clinical success in an intensive care setting.