There is arguably nothing more heart-wrenching than a patient who is suffocating. How you handle these patients could be the difference between life and death. Some colleagues can be hesitant to admit these patients and may advise clients to take them to an emergency or referral facility that may be much farther away. It doesn’t have to be that way.
Short-term, there really is no risk to oxygen therapy. So even if the disease process were not oxygen-responsive, there is no harm in providing therapy while you figure things out, assess the severity of the disease, and obtain diagnostics. Providing oxygen is an easy way to buy time.
Empower your nurses to start some sort of oxygen therapy when your patient is exhibiting any of the following situations:
• dyspnea of any kind;
• shortness of breath;
• abnormal respiratory sounds;
• cyanotic gums;
• severe anemia or hemorrhage;
• increased respiratory rate;
• head trauma; and/or
• lateral recumbency.
Although arterial blood gas analysis would be the most accurate way to assess pulmonary function, it is rarely available in general practice. Pulse oximetry is a cheaper and more available option. You are looking for an SpO₂ of at least 93 to 95 percent.
Regardless of the reason for oxygen therapy, try to use the least stressful delivery modality.
Short-term therapy does not require humidification, but long-term treatment does in order to help prevent drying of the epithelium and possibly causing infections.
Even five minutes of oxygen therapy can alleviate the struggle or turn the tides for that patient. Here are seven modalities to deliver oxygen supplementation to dogs and cats in everyday practice.
Flow-by oxygen is the simplest to provide. This is administered by placing the end of the oxygen hose (most often from your anesthesia machine) by the animal’s nose. Since this technique does not require using a mask, most pets tolerate it with little to no fighting.
This modality only increases the oxygen concentration slightly above room air, so it’s not ideal for respiratory distress. However, it’s a good, quick first step, which gives you a moment to think about your next best option.
Incidentally, this technique is most often used to pre-oxygenate patients prior to induction or during sedation.
Administering oxygen with a mask provides the patient with a higher concentration than flow-by oxygen. Obviously, keeping the black rubber on the mask allows a tighter fit and higher oxygen concentration. The main drawback is that not all patients will tolerate the mask over their face.
In a respiratory distress situation, the last thing you want your patient to do is panic, so it is not an ideal option in nervous patients. You may have to resort to flow-by oxygen or use another modality, such as moving your patient to an oxygen cage.
The oxygen saturation increase is highly dependent on how tightly the mask is fitted to the patient’s face. If the mask is very secure, carbon dioxide may build up, which may result in CO2 rebreathing. Therefore, it is recommended to aerate the mask periodically. This method also is used for patients undergoing a quick procedure.
Commercially available or makeshift oxygen cages range from independent units utilized only for this purpose to a Plexiglas panel that replaces a cage door. In a pinch, when it’s truly your only option, you can even create an oxygen cage by placing plastic or Saran wrap taped over a cage door and pumping oxygen in through it. You can use a similar system with a small patient in a carrier covered by a large plastic bag. Please understand these are not ideal solutions, but merely replacement options when you are desperately trying to save a life.
Regardless of which style you use, you must keep a close eye on temperature and humidity inside the cage. A closed cage does not take very long to heat up. Some top-of-the-line cages have internal controls you can preset to automatically make the adjustments needed to provide the appropriate environment. Cheaper alternatives include the use of a digital thermometer and ice packs and replacing them regularly during the therapy. If the oxygen cage is out of line of sight, make sure to check on a dyspneic patient every few minutes.
If you don’t have an oxygen cage or your patient is too large, you can use an “oxygen hood.” Place an e-collar over the patient’s head—choose a size larger than ideal. Then place Saran wrap over the wide end of the cone, ideally secured by your MacGyver-like nurse. Leave room for ventilation. The same temperature and humidity concerns apply here. Administer the oxygen by feeding a small oxygen line or a red rubber catheter into the hooded area. And speaking of red rubber…
Nasal oxygen is a very efficient way to provide oxygen supplementation and can be delivered by a nasal cannula or by a number 5 or 8 French red rubber catheter placed with the use of local analgesia. It is then secured with tape and staples or sutures. One line is usually adequate. Placing two cannulas or catheters allows you to get the same oxygen saturation as one while using a lower flow rate. The main challenge is premature removal, which can be prevented with the use of an e-collar.
A nasotracheal catheter also can be used to help a patient in respiratory distress or pets recovering from anesthesia. A red rubber catheter is placed through a nostril and advanced until you visualize it past the soft palate and into the proximal trachea. The catheter is secured and protected like a nasal cannula. Once your patient has sufficiently recovered, you can easily remove the catheter without much discomfort.
Of course, the most effective way to deliver 100 percent oxygen is to intubate the patient and inflate the cuff, which requires anesthetizing the patient. This extreme situation is usually reserved for intractable dyspnea. Real-life examples include end-stage laryngeal paralysis, laryngeal collapse, or brachycephalic syndrome. If the patient can’t breathe on his own, you will either need to ask a nurse to “breathe” for the patient, or you can use a ventilator if it’s available. The presence of a tracheostomy tube is the only situation where the patient can be “intubated” though awake.
Even if you don’t currently have oxygen in your facility or all your oxygen tanks are empty, you can still save a life. Visit your local medical supply store and pick up an oxygen tank with a regulator and a line. This can buy time before your client drives to the closest specialty facility.
Bottom line: oxygen supplementation is an easy way to stabilize a dyspneic patient while you decide what the next best step is.
Phil Zeltzman, DVM, DACVS, CVJ, Fear Free Certified is a board-certified veterinary surgeon and author. His traveling surgery practice takes him all over Eastern Pennsylvania and Western New Jersey. You can visit his websites at www.DrPhilZeltzman.com and www.VeterinariansInParadise.com. AJ Debiasse, a technician in Stroudsburg, Pa., contributed to this article.