The Color Purple
Purple. Dreaded purple. One of the scarier colors that we deal with in veterinary medicine. Why is my patient purple? Lack of oxygen and impending death, that’s why. Obviously there are things in life that occur which are completely beyond our control, some things however can be avoided. Keep your critical patients highly visible, remove clipboards from cage doors, walk cards, whatever, you need to be able to see that patient at all times.
So what constitutes a critical patient?
- HBCs (hit by cars). An animal hit by a car, with no obvious trauma, can die in a very short amount of time from pulmonary contusions and shock. Don’t be fooled by their spry behavior and constantly wagging tail. 2-view radiographs should always be performed to determine any internal injuries.
- Heart patients. The heart is a tricky muscle, which needs delicate medical control when it is not functioning properly. Cats suffering from saddle thrombus fall into this category as well. Pay close attention for any signs of abnormal breathing and rhythms. If you are not sure what you are seeing or hearing ask a doctor.
- Post-operative patients. Even when you think they are recovering normally, their condition can rapidly deteriorate; for example a cat with undiagnosed HCM (hypertrophic cardiomyopathy). Patients that are either brachiocephalic, have a history of tracheal collapse, or laryngeal paralysis are at particular risk and usually do better with one-on-one recovery.
- Patients experiencing anaphylaxis either from an insect bite, vaccine, or an allergic reaction to a medication can easily swell past the point of intubation if not treated immediately.
- Patients with severe upper or lower respiratory disease. These patients may be more difficult to monitor due to the need to keep them isolated from the rest of the hospital. Do not just assess through a window, go in and take visual vitals if they are highly contagious.
- Any patient coming in with dyspnea or abdominal breathing whether etiology is known or unknown.
Tips for avoiding the color purple.
- Note any allergies the patient may have, vaccine or otherwise.
- Review your patient’s medical history, any current problems or conditions.
- Before intubating a patient, check your endotracheal tubes to be sure they are not obstructed by blowing air through them, especially small tubes. (remember that healthy young cat that mysteriously turned blue immediately following intubation, but then quickly pinked up after the tube was pulled? This may have been why). Also pre-inflate the cuff to make sure there is no leak that will prevent your patient from being ventilated properly.
- Before starting an anesthetic procedure, make sure your oxygen tanks are adequately full and none of the connections are leaking. Each anesthetic machine should be checked for leaks every morning and documented on a log.
- During the anesthetic procedure, if your patient’s color is deteriorating and/or the pulse ox is decreasing, first check your anesthetic machine and connections! The oxygen may be off (oops – forgot to turn it on when the patient was moved from the prep area), or a connection may have become unattached or was never attached (oops – someone didn’t switch properly from a rebreathing system to a non-rebreather), or the pop-off valve is closed and you assumed it was open (oops – the breathing bag is huge, the patient has no room to breathe, and now you risk lung damage). All of these problems may happen more often than you may think.
- Always make sure the proper breathing system is being used for your size patient. Follow these guidelines:
- Animals weighing < 20 # nonrebreather with 1 liter bag
- Animals weighing 21-60# rebreather with 2 liter bag
- Animals weighing 61-120 rebreather with 3 liter bag
- Animals weighing >120 # rebreather with 4 or 5 liter bag
- Always use whatever monitoring equipment you have available, but never rely completely on it. They are just machines! The careful monitoring of mucous membrane color, CRT, pulse rate, heart rate, jaw tone, eye position, palpebral reflex, and pain response by a skilled technician is invaluable and cannot be replaced. The normal and abnormals of every parameter must be indelibly imprinted in your brain!
- Never leave a critical patient’s side without notifying another technician and conveying the patient’s vitals and risk for complications.
How to assess proper endotracheal tube (ET) placement.
- Learn to “feel” the cartilage tracheal rings as you intubate.
- Inflate the cuff slowly with your ear to the pet’s muzzle; inflate only to the point where you can no longer hear air leaking around the tube.
- After inflating the cuff, put your cheek to the tube’s end and feel the air being exhaled.
- There should be no air moving around the tube.
- Do not assume that if your patient is “moving the bag” that the ET is properly placed. It may still not be in the correct position for effective ventilation even though some air may be getting through.
- Chest excursion should occur when manually compressing the breathing bag.
- If in any doubt, re-intubate. Don’t wait several minutes to assess or wait for someone else to come and check – your patient may wake up or may turn purple!
- And yes, it is possible for a dog to swallow an ET that has been incorrectly placed in the esophagus.