References

Divers S, Stahl S. Mader's Reptiles and Amphibian Medicine and Surgery, 3rd edn. St. Louis: Elsevier; 2019

Doneley B, Monks D, Johnson R, Carmel B. Reptile Medicine and Surgery in Clinical Practice.Oxford: Blackwell; 2018

Girling S, Raiti P. BSAVA Manual of Reptiles, 3rd edn. Gloucester: British Small Animal Veterinary Association; 2019

Lerche P, Thomas J. Anesthesia and Analgesia for Veterinary Technicians, 5th edn. St. Louis: Elsevier; 2017

Nugent-Deal J, Palmer Holtry K. Principles and Practice of Veterinary Technology, 3rd edn. St. Louis: Elsevier; 2011

Plumb D. Plumbs Veterinary Drug Handbook, 7th edn. Stockholm: Wiley-Blackwell; 2011

Wilson B. Exotic Animal Medicine for Veterinary Technician, 2nd edn. Ames: Wiley-Blackwell; 2010

Practical

How to intubate a reptile

02 December 2019
Practical
6 mins read
02 December 2019
Volume 10 · Issue 10

Abstract

Intubation in reptiles can be challenging in some species. From their anatomy, anaesthetic protocols, technique, and recovery, reptiles have several special considerations. With the right instruments, intubation can be performed successfully on reptiles. In this article, we will discuss the various tools that help to properly intubate reptiles. We will also discuss techniques that will help with intubation on reptile patients as well as protocols for anaesthesia and recovery.

The highest standard of care for anaesthesia and support should be attempted for all patients, including reptiles. Intubation is the preferred method to allow ventilation and emergency ventilation if required. Reptiles are best intubated due to the pressure on the simple lungs during positioning for procedures. The pressure can interfere with stimulation for reptiles to breathe on their own (Doneley et al, 2018). Reptiles require a different technique of intubation to mammals. In this article, we will discuss the reasons for intubation, the supplies needed to successfully intubate reptiles, and the techniques for proper intubation in reptiles.

Overview of intubation

The purpose of intubation is to establish an airway for better delivery of anaesthetics and to allow manual ventilation. Intubation is the act of placing a tube down the patient's trachea to have direct access to the airway before, during, and for a brief period after their procedure (Box 1).

Box 1.Pros of intubation

  • Access to patient's airway
  • Provide a consistent form of anesthetic drugs to the patient throughout the procedure
  • To provide a consistent flow of oxygen to patient
  • To provide oxygen to the patient when the patient is not breathing on its own
  • Have the ability to more efficiently provide oxygen during an emergency

Unique qualities and considerations for reptiles

Intubation can be challenging for any species. Reptiles represent a number of unique considerations. First, many reptiles have very strong jaw tone, so the patient must be at a certain plane of anaesthesia before intubation can be performed. Attempts to intubate before the patient is properly sedated can lead to broken tubes, damage to the patient's trachea, or trauma to the nurse. Attempts to intubate a reptile that is not at an appropriate plane of anaesthesia can lead to injury to the patient and is an unethical practice of medicine.

The challenge with proper pre-medication and induction is that it can take quite some time. Reptiles metabolise drugs at a very slow rate which can make achieving an appropriate plane of anaesthesia a lengthy process. The term anaesthesia may be defined as a loss of sensation (Lerche and Thomas, 2017). This is the desired effect on reptiles for a successful and safe intubation. Pre-medication and induction drugs can be given intravenously (IV) and intramuscularly (IM); IM administration is technically simpler but has a slower onset than IV administration. Plenty of time should be allotted before the procedure to be sure the reptile is prepared appropriately (Doneley et al, 2018) (Figure 1).

Figure 1. Proper handling of the head is key to successful intubation in reptiles. Pulling down on the skin around the mandible helps to make the epiglottis more prominent.

Keeping the reptile at its preferred temperature zone (PTZ) is important to maintain the metabolic rate of the reptile (Divers and Stahl, 2019). Be sure to provide supplemental heat as needed and monitor the ambient temperature of the reptile carefully.

Supplies for reptile intubation

There are several tools that can help with intubation in reptiles (Figure 2):

  • Mouth speculum: sometimes patient's jaws are difficult to hold open due to their anatomy, and speculums help to hold the mouth open during intubation. Mouth speculums also aid in controlling the tongue in order to better visualise the glottis (Doneley et al, 2018). If the patient is not at an appropriate plane of anaesthesia repeat doses of drugs need to be administered before attempting intubation. Items used for speculums include rigid metal speculums. These should be used with care as they can cause injuries to the soft tissues of the mouth. Speculums can be tricky to use if you do not gauge the sizing correctly (Figure 3). To insert the tube, pass it through the speculum. If the connector part of the tube is larger than the speculum it can get stuck, so that the tube is not fully in place and the speculum is more or less attached to the patient. Instead of a mouth speculum, at the author's practice we prefer to use a plastic credit card (Figure 4). This performs a similar task of opening the reptile's mouth and flattening the tongue in order to see better for tube placement. It avoids having to pass the tube through a speculum with the potential of it being caught. The credit card is also flat, so it slips well between the reptile's lips in order to work the mouth open for tube placement, and it does not cause potential trauma to the patient's jawline.
  • Tracheal tube stylet: a stylet for your tube is extremely helpful when intubating reptiles. The stylet provides rigidity to the tube as it is being passed into the reptile's trachea. (Figure 5).
  • Pen Light: a pen light, head lamp or other light source is extremely useful for visualising the epiglottis (Figure 6).
  • Tongue depressor: the endotracheal tube can be tricky to keep placed when manipulating a reptile patient during surgery. The tendency for a reptile tube to slip is fairly high due to the length of tube and the fact that most reptile heads are not shaped well to hold tape. One way to alleviate this problem is to place a section of a tongue depressor under the patient's chin and tape the tube to the tongue depressor. This offers both rigidity for the tube and a solid platform for it to rest on. This also offers a nice surface for the tape to adhere to (Figure 7).
  • Endotracheal tube: typically, a non-cuffed endotracheal tube is used for intubating reptiles. Most reptiles have large oral cavities and their glottis is rostral inside the oral cavity, making intubation easy to visualise (Girling and Raiti, 2019) (Figure 5). A Coles® tube is best for intubation in reptiles due to the narrow tip of the tube which gradually gets larger. In reptiles the trachea bifurcates more cranially than in mammals. This tube allows for proper placement and a good seal on the trachea (Wilson, 2010).
Figure 2. Here are a variety of tools to aid in the reptile intubation process: (left-right, top-bottom) various masks to deliver anaesthetic gas if your patient is too light to intubate, cotton-tipped applicators can help in holding and manoeuvring the tongue during intubation, tongue depressor can help hold the tongue to visualise the epiglottis, tape is key to holding the tube in place once intubated, various un-cuffed tubes with stylets to help guide the tube in place, mouth speculums help to hold the mouth open during intubation, laryngoscope and pen lights help to visualise inside the mouth during intubation, an old credit card helps with initially opening the reptile's mouth.
Figure 3. One nurse holds the patient's head as well as holds the mouth open while the other nurse holds the patient's tongue and begins to insert the mouth speculum.
Figure 4. Mouth speculums and old credit cards aid in opening the mouth and helping keep the mouth open during intubation.
Figure 5. Here are un-cuffed intubation tubs of various sizes with stylets to help guide the tube and give it a bit of rigidity when being placed in the patient.
Figure 6. Pen lights and laryngoscopes provide a light source to visualise the intubation process in the patient's mouth.
Figure 7. Cotton-tipped applicators, tongue depressors, and tape are all used during the intubation process, mainly to secure the tube once placed in the patient.

Intubating a reptile

The steps in the author's practice for intubating a reptile are similar to that of intubating any other patient:

  • Administer pre-medications to the patient. Inject the patient with an opioid 30 minutes before administering anaesthetic drugs (Girling and Raiti, 2019). The author's anaesthetic drug of choice is alfaxalone given IM or IV (Plumb, 2011). The most common reptile venepuncture site is the caudal tail vein or ventral coccygeal vein (Nugent-Deal and Palmer Holtry, 2011). Multiple doses are typically required, given roughly 10 minutes apart to reach the necessary level of sedation. Alfaxalone may also be given IV to effect (Girling and Raiti, 2019).
  • The patient should be in sternal position facing the nurse for intubation. A second nurse may be used for restraint in larger patients or difficult intubations. If a patient is not at a proper level of anaesthesia, repeat doses may be given (Figure 1).
  • One hand is used to hold the patient's head as well as to position the speculum or credit card in the patient's mouth. The other hand holds the endotracheal tube and manoeuvres for placement (Figure 3).
  • In most reptiles, the epiglottis is at the base of the tongue and is fairly easily visualised (Doneley et al, 2018). Some reptile patients can hold their breath for quite some time, so patience is key to wait for the opportunity to place the tube (Figure 8).
  • Once the tube is in place, anaesthetic gas should be attached as soon as possible to ensure the reptile does not start to wake up and dislodge the tube (Figure 9).
  • The tube should be secured with tape either around the reptile's head or to the tongue depressor underneath the reptile's chin (Figure 10).
Figure 8. Here one nurse holds the patient's head steady and mouth open while the other nurse inserts the tube. You can see the opening of the glottis as the narrow slit just under the tube.
Figure 9. The patient is intubated and connected to oxygen. You can see how the tube is secured to the patient using tape around the tube and wrapped around the patient's head.
Figure 10. Taping the tube in after intubation can be the most difficult part. The tube can slip easily so care must be taken, and the tube taped securely to the patient. Tape should be wrapped around the patient's head at least once, but twice is preferred in a crisscross pattern.

Postoperative recovery

After surgery, the majority of reptiles will not recover from anaesthesia as quickly as mammals (Girling and Raiti, 2019). In the author's practice, reptiles are typically moved from the surgery suite to the recovery area with their endotracheal tube still in place. A bag valve mask (BVM) instead of pure oxygen is used for ventilation; once the reptile is consistently breathing spontaneously, assisted breathing can be discontinued and the endotracheal tube removed (Doneley et al, 2018). An BVM is preferred to give a mixture of oxygen and CO2 which inspires the reptile to spontaneously breathe.

Conclusion

Intubation in reptiles can have some challenges, but with the right tools and expectations, it can be successfully performed on any patient.

KEY POINTS

  • Picking the right instruments will help with intubation techniques in reptiles.
  • Providing adequate anaesthesia is essential for smooth intubation.
  • Proper taping techniques for reptiles ensure that tube placement is secure.
intubation
reptiles
anaesthesia
instruments