Errors in Veterinary Medicine can be broadly classified into two categories. These two categories include errors in thought process and technical errors. Both categories of errors are equally dangerous to patient health, relationships with clients, and financial success of a practice. The good news is that both categories of errors can be properly analyzed, trained for, and protocols developed for their prevention. In this section, we will explore the most common types of errors in each of these two categories.
Errors in thought process are often the most difficult errors for a veterinarian to accept and understand, and on the whole are less understood, and discussed far less in terms of types of medical errors within the veterinary community. The attending veterinarian in a case is often the responsible party for these types of errors, and can suffer a great deal of emotional turmoil in the form of shame, humiliation, and regret when these type of errors occur. Familiarizing yourself with these types of errors and applying them to the cases you commonly see in your practice is an excellent way to prevent these types of errors in your practice. Errors can also be role played at staff meetings to further understand how they occur and how to prevent them. Dr. Phil Zeltman, DVM, DIPL. ACVS effectively explores this category of errors in an article titled “Medical Errors and How to Avoid Them”. In this publication, Dr. Zeltzman effectively breaks this category of errors down into 7 types; anchoring error, attribution error, availability error, commission bias error, satisfaction of search error, and affective error.
- Anchoring errors may also be known as distorted pattern recognition, or a shortcut in thinking. “This type of error occurs when we cherry pick symptoms to confirm our (biased) impression. Dr. Zeltzman uses the example of an 6 year old Labrador with a lameness of 3 months duration that is progressively getting worse. In the example, he highlights how easy it is to latch on to a diagnosis of an ACL tear due to experience, breed, and presentation. Dr. Zelzman reminds us how important it is to be sure that all of the signs fit with your working diagnosis to avoid this type of error. In this example, the pet can “sit squarely”, has no obvious joint effusion, no stifle pain, and no appreciable drawer sign. Not considering these signs, or lack thereof makes it very easy to “latch on” to or rationalize a partial ACL tear diagnosis without considering hip dysplasia in the differential diagnosis.
- Availability errors are described as errors where the “tendency to judge the likelihood of an event by the ease with which relevant examples come to mind” occurs. “In other words, if you see a string of 10 similar cases (pneumonia, SQ lipomas, foreign bodies…), you are more likely to assume the 11th patient with somewhat similar signs has the same diagnosis. That diagnosis is “available”, it’s familiar, it’s top of mind”. Dr. Zeltzman states that you can, “Avoid this error by considering each patient as an individual, independently of previous patients’ diagnosis”.
- Commission Bias Errors can be one of the most humiliating and humbling type of thought process errors, as “it is more likely to occur with a doctor who is overconfident, whose ego is inflated”, but can also occur “when a (doctor) is desperate and gives in to the urge to do something. This can be caused by a call to action by an impatient client”. This error is based in “the tendency towards action rather than inaction”. The very effective example that Dr. Zeltzman uses for this type of error are cases where the timing of surgery is unclear, such as a gastric dilation volvulus, diaphragmatic hernia repair, or jejunal foreign body, and you are faced with the decision to immediately intervene surgically vs. provide further stabilization of the patient. The statement he makes, “Cutting a patient open is an easy thing to do. Knowing when to cut is an art form”, resonates strongly with each and every one of us in the field of veterinary medicine.
- Satisfaction of Search Error is an error that we can all relate to, even in non-veterinary medical life. The example that Dr. Zeltzman uses is, “You are satisfied after finding a gastric foreign body, but “forgot” (or missed) a second one in the ileum. Or you are satisfied after re-positioning a bloated stomach and masterfully performing a gastropexy, but unfortunately “forgot” to explore the abdomen and remove the gallbladder mucocele waiting to pop”. Dr. Zeltzman advises, that you can, “Avoid this error by keeping an open mind and being thorough in your physical, radiographic, and surgical evaluation”.
- Affective Errors, “can stem from the desire to “save” an animal we really like from fancy testing, or a client we have bonded with from high expenses”. Dr. Zeltzman points out an example that illustrates just how emotionally traumatic this type of error can be when it occurs. The example he uses involves missing a diagnosis of lymphoma by treating a well-known patient with supportive care only, due to the bond you have formed with the client. After an extended period of unsuccessful supportive care a work up is pursued and you learn that you have missed the lymphoma diagnosis. Dr. Zeltzman correctly points out that you have now lost that extended period of time, that could be crucial to the treatment of the lymphoma. Dr. Zeltzman advises that you can avoid this error, “by avoiding making financial decisions and by focusing on sound medical recommendations”. The irony of this type of error is illustrated perfectly when Dr. Zeltzman points out that, “Our affection for the patient or client can lead to a medical error that will actually hurt them”.
- Interpretation Errors are one of the most difficult errors in thinking to plan for and prevent. The difficulty in dealing with this type of error is effectively illustrated by Dr. Zeltzman when he cites a human radiology study from Michigan State University. In the study, 60 radiographs were presented to human radiologists with the simple question, “Is this study normal?”. They disagreed with each other in 20 percent of the cases. This is called “inter-observer variability”. Worse, when the same radiologists read the same 60 films at a later date, they disagreed with themselves in 5-10 percent of the cases. This is called “intra-observer variability.” Interpretation errors are a true human factor error. The only effective way to deal with and prepare for this type of error is constant continuing education and practice within our field. Human factors can never be eliminated completely, but staying at the top of our game with training and education can certainly decrease the influence of these factors tremendously.
In summarizing his article, Dr. Zeltzman’s “Moral of the Story” is a profound statement about human nature and our moral and ethical obligation as practitioners to learn from our mistakes.
“Like it or not, mistakes do and will happen. Notice that none of the mistakes described is due to complete ignorance or gross negligence. They are often related to tricks plaon yed by the human mind. Assuming we can conquer hubris and denial, not doing anything about making mistakes would be irresponsible and unethical. Sure, we can blame ourselves after we make a mistake, but then we should learn from them. Ironically, making mistakes is part of the learning curve. We should ask ourselves if there is something we could have done differently to prevent the error. We also should ensure that our error never happens again. Even better, sharing with others will hopefully prevent them from making the same mistake. This positive attitude ultimately will make us better doctors or technicians and will help future patients.” The bulk of the errors that fall into the second classification of errors, technical errors, are errors in medication management. Although there are some technical errors that fall outside of the subcategory of medication management, our focus will be the errors in medication management due to how common these errors are. The Irreverent Veterinarian points us to a list presented by the FDA, CVM in his/her article, “The Irreverent Vet Speaks Out on Medication Errors”.
According to the FDA,CVM, an agency that works to prevent veterinary drug medication error, the following major causes have been identified for these mistakes. The reasons for medication errors in dogs and cats include, but are not limited to:
- Medication names that look alike or sound similar.
- Labels that look similar, or are unreadable due to font size, style, lack of background contrast, designs that hide information, illegible writing, or overcrowded information.
- Labels that are missing information.
- Packaging with inadequate or inconsistent presentation of drug strength, dosage form (such as tablets or capsules), or active ingredients.
- Drug dosage devices (such as oral syringes) that are difficult to use because of poor design or inadequate directions for use.
- Use of error-prone abbreviations or symbols on written prescriptions.
- Illegible handwriting on written prescriptions.
- Miscommunication while verbally prescribing orders.
- Human error which results in filling the prescription with the wrong medication or strength of medication.
- Owners giving medication to the wrong pet or in the wrong amount.
Now, think back to the information provided in the section on the history of medical errors and remember how many of the errors above are the same errors that occur in the human medical profession. So, it seems to reason that we can use some of the same methods of error reduction in veterinary medicine that has been used in human medicine.
In addition to the list provided above, common medication errors within the clinical setting by veterinarians or technicians include:
- Administering medication both oral and injectable to the wrong patient.
- Administering medication by an incorrect route of administration, eg: giving a Penicillin G, propofol, or potassium chloride injection intravenously.
- Administering the wrong amount of an injectable medication due to a decimal point error in calculation of dosage.
- Administering the wrong amount of an injectable medication due to misinterpretation of a written order that contains decimal points.
- Administering the wrong amount of an injectable medication due to the misinterpretation of a written order that does not contain a leading zero, eg: 0.5ml vs. .5ml.
- Miscalculating dosages by using the patient’s weight in pounds instead of using the patient’s weight in kilograms.
Now that we have explored the common types of errors that occur in veterinary medicine we will discuss Root Cause Analysis (RCA) and present case studies where the RCA, when applied, will help prevent future errors of the same nature.