When translating terms that refer to life-threatening conditions, finding the correct equivalent is especially crucial. Unfortunately, it’s not always easy.

During a translation project, the term “stroke” came under intense scrutiny at a review session that included translators, interpreters, doctors and community representatives. One interpreter suggested the translation “embolia”; another preferred “derrame cerebral” (cerebral hemorrhage). A third interpreter pointed out that both “embolia” and “derrame cerebral” were kinds of strokes, but the problem was that they had different or even opposite causes. Commonly-used references may yield translations for a wide variety of synonyms, superordinates or hypernyms, and hyponyms [defined later in this article]: embolism, brain hemorrhage, paralysis attack, sudden attack, brain attack, apoplexy.

According to a few reference materials commonly consulted by medical interpreters:

Stroke: n. 1. embolia cerebral, apoplejía; ataque súbito; .... (1996)

Stroke: n. (cerebrovascular event) derrame m cerebral, embolia. (1992)

Stroke: 5. (Med) ataque m de apoplejía, derrame m cerebral (2009)

stroke: ataque de parálisis, derrame cerebral, embolia, embolio (1996)

stroke: 1. embolia cerebral, apoplejía; ataque cerebral (2012)

Considering the equivalents provided without definitions, and with little to no assistance on how to choose between the alternatives, it’s no wonder some interpreters might say, “My dictionary says a stroke is an embolism,” while others might equate it to a brain hemorrhage instead.

Without further explanation or guidance, how are we to choose the most appropriate term?

The serious concern is that interpreting “clot” instead of “hemorrhage” could possibly create a problem in the diagnosis and further treatment of the patient. At this point, I would like to propose some basic steps that interpreters or translators should follow to assess the reliability of their sources and to choose between terms found in bilingual dictionaries or recommended by colleagues.

Step 1: Define the Source Term

When trying to assess the adequacy of an equivalent, first look up a definition of the source term in the source language to make sure you understand it sufficiently. A simple Google search for the term “stroke” would return ample sites, from which you might select one that is backed by a reputable medical organization or association. Here are some of the more reliable ones that come up:

PubMed Health: Gives a short description, and mentions that it is sometimes referred to as a “brain attack.” It also includes the term CVA, without explaining it.

The American Stroke Association: Very simple and didactic, with particularly helpful graphics. If you click on the tab “About Stroke,” you will find a new tab titled “Types of Stroke” which lists three: Ischemic (clots), hemorrhagic (bleeds), and TIA. What’s useful about this breakdown is the inclusion of the high-register terms (ischemic or hemorrhagic) followed by the corresponding low-register term next to them (clots, bleeds).

Apparently, both bleeding and clotting can produce the same effect: Inadequate blood flow to an area of the brain. Though the Gale Encyclopedia of Medicine defines stroke as “the sudden death of brain cells in a localized area due to inadequate blood flow” (Gale Encyclopedia of Medicine, 2008, quoted in TheFreeDictionary), not all strokes involve death of brain cells. The following definition of a CVA, from the National Library of Medicine, is more precise: “A sudden, nonconvulsive loss of neurologic function due to an ischemic or hemorrhagic intracranial vascular event. In general, cerebrovascular accidents are classified by anatomic location in the brain, vascular distribution, etiology, age of the affected individual, and hemorrhagic vs. nonhemorrhagic nature.” (From Adams et al., Principles of Neurology, 6th ed, pp777-810, quoted in ICD9.)

In this article I’ve chosen to focus on the distinction between embolic stroke and hemorrhagic stroke, due to the common use of “embolia” and “derrame cerebral” in materials available to medical interpreters and in usage by Spanish-speaking patients in the U.S. However, it might be beneficial to look at the more exhaustive list of conditions included under “stroke” at www.stroke.org: ischemic stroke, embolic stroke, thrombotic stroke, large vessel thrombosis, small vessel disease/lacunar infarction, and hemorrhagic stroke. Some patients might say they’ve had a “trombosis” and it would be good to know the difference between a “thrombotic stroke” and an “embolic stroke,” even though they might be similar.

Step 2: Research Definitions of the Target Terms

The second step is to look at the options given in the target language, whether obtained from another translator, interpreter, bilingual dictionary, translation or any other source, and explore the definitions of those terms in target-language monolingual sources, including dictionaries and non-translated sites.

In the case of “stroke,” here’s a list of the terms above that would have to be explored: embolia cerebral, apoplejía, ataque súbito, derrame cerebral, ataque de parálisis, and ataque cerebral. You could search for their meaning in monolingual Spanish sources, whether general or specialized dictionaries, and other educational materials. Finding them recorded in a general monolingual dictionary might indicate whether these terms have gone beyond the technical domain and have been adopted by the population at large. One such source for Spanish is the dictionary of the Royal Language Academy of Spain, 22^nd edition (Diccionario de la Real Academia Española, or DRAE)[1]

The DRAE states that “apoplejía” comes from the Latin and Greek words meaning paralysis, and in medicine is defined as a more or less complete, and usually sudden, suspension of some brain functions due to hemorrhage, obstruction, or compression of an artery in the brain (See DRAE and search for “apoplejía”).

There are no entries for the combined terms “ataque cerebral” or “ataque súbito” in the DRAE, but you can search for them online. I will discuss “embolia cerebral” and “derrame cerebral” further under step 3 below, and “apoplejía” in steps 4 and 7 below.

Another term that seems worth exploring is “parálisis.” The definition of paralysis by itself, in the DRAE, could be translated back into English as: “privation or reduction of movement in one of the parts of the body.” The question is whether a “paralysis attack” can only be caused by stroke, or whether there might be other causes.  A quick search shows that possible causes of paralysis also include trauma, polio, botulism, MS and Guillain-Barré syndrome. There is also a genetic disorder called hypokalemic periodic paralysis that causes periodic paralysis attacks.

To fully research definitions in the target language, you would have to go beyond general dictionaries and look for specialized publications in the target language. If you do not own reference materials in the target language, the best source would be to search online, but make sure you are looking at original texts and not translations! I will explain further research on target term definitions and review actual usage of the various options among native speakers in step 4 below.

Step 3: Compare the Scope of the Source and Target Terms

The third step is to compare the source and target terms and determine whether they are equally narrow or broad. To be precise in our translation, we should avoid replacing broader terms with narrower terms. “Stroke” is a broader term, and our goal as translators or interpreters is to find an equally broad term in Spanish or whichever other language is our target.

You might consider reading the second chapter of In Other Words by Mona Baker (2^nd edition, 2011), on the topic of superordinates (hypernyms) or hyponyms (referred to as hiperónimos and hipónimos in Spanish). A superordinate term is a more general term, for a whole category, such as “fruit.” A hyponym is a narrower term that might refer to objects or terms within that general category, such as “apple” or “orange.” While all apples are fruits, not all fruits are apples. While all cerebral hemorrhages are strokes, not all strokes are cerebral hemorrhages.

A fellow conference interpreter describes mismatch in scope by saying: “Make sure you don’t open or close up the term.” I think that is excellent advice. As much as possible, we should try to keep the level of generality of the source term in the target.

But what happens when the target language does not have an equivalent broad term? In that case, you might have to resort to listing some of the options, as you do in math when you define a set “by extension,” enumerating all the members of the set (Example: A= {2, 4, 6, 8, 10, ...}), instead of “by intention,” when you give a defining property that encompasses all the members of the set (A= {all even numbers}). When I worked at the hospital, I used to tell all interpreters to follow the term we had picked for an equivalent of stroke with the phrase “como por ejemplo derrame o embolia cerebral [such as a cerebral hemorrhage or embolism, for example].” That way, if the patients didn’t know the general term we were using, they might understand one of the specific terms provided by way of example.

The danger of using the wrong specific term is that you could ask a patient if they ever had a cerebral embolism, and they might say no, but they had a brain hemorrhage, which the doctor would want to know. A doctor examining a patient on Coumadin, a blood thinner, might be puzzled to hear the patient had an embolism, and think of increasing the dose, or, might be concerned if told that the patient had a history of brain hemorrhage, and think of reducing the dose. (Back to the comparison with fruit, imagine if the nutritionist asked the patient if they ate fruit, the interpreter asked if they ate apples, and the patient said no because they only ate oranges).

Step 4: Compare Usage of Target Terms (Register and Dialect)

Step 4, which can be combined with step 2 above, is to compare the target terms that might be closer in meaning and overall scope to the source term, and see how widely understood they would be by the target audience. At this point you focus on searching for parallel texts.

A parallel text is a text written in the target language with a similar purpose to the source text you are translating; a parallel text is not a translation. For example: A prescription written by a doctor in a Spanish-speaking country can be compared to a prescription written in the U.S. Or, patient education materials such as how to prepare for surgery, found on the website of a hospital in a Spanish-speaking country, versus those issued by a hospital in the U.S. Spanish translations posted in Medline do not constitute parallel texts.

”Stroke” is widely used in English as a low-register term. Is there a Spanish equivalent that is equally understood by the general Spanish-speaking population? One way to check for usage is to Google the terms you found in your glossary and see if they are used in patient education sites from other countries. Some of the equivalents that are accurate or equivalent in meaning, but might have to pass this usage test, are: apoplejía, and the more recently-adopted equivalent, ataque cerebral (used as a translation of “brain attack”). When doing this kind of search, I try to eliminate Spanish-language sources from the U.S. (Medline, etc.), and look for sources in specific countries.

One way to search for these texts is to do an advanced search in Google and search within the domain of the country you are looking for. For example, go to www.google.mx for searches if you are working into Mexican Spanish. In my case, translating for the U.S. Spanish-speaking audience, I search for terms mainly in the countries with the largest number of speakers in my target audience, though I might include countries like Spain and Argentina for purposes of comparison. I keep track of the exact search string I use, making sure I’m searching only in pages written originally in Spanish, and I compare Google counts. Here are the counts I obtained in the last search I performed:

accidente cerebrovascular site: .mx (15,400 hits) .pr=88; .cu=26,400; .cr=1,740; .co=15,000; .es=73,700; .ar=46,800. General hits= 1,220,000.

apoplejía site: .mx=41,600; .pr=19; .cu=57,800*; .cr=1,310; .co=8,260; .es=25,900; .ar: 9,180. General hits: 403,000.

*includes a lot of instances that are not stroke: apoplejía abdominal, hipofisaria, etc.

“apoplejía cerebral” site: .mx=132; .pr=367; cu=24; .cr=452; .co=66; .es=1,610; .ar:147. General hits: 13,700.

“ataque cerebral” site: .mx (10,700 hits) ) .pr:9, .cu=1,110; .cr=228; .co=7,710; .es=6,660; .ar: 16,600. General: hits 190,000 hits.

These hits include many on sites that are translations of U.S. sites posted in other countries, so they are not really parallel texts per se. To know if it is really a parallel text, you have to read through the text and see if you find local usage, as well as identify the actual source or author.

The following are examples of postings of a U.S. source in Mexico, which tend to show “ataque cerebral” as a synonym of “derrame cerebral,” even though further down in the text, they might explain that there are two kinds of “ataques cerebrales,” one caused by bleeding and one from clotting:  

http://www.paraqueestesbien.com.mx/hombre/cabeza/sistemanervioso/sistnerv1.htm: Given the “Roche” symbol on the top of the page, it’s probably a translation.

http://www.hcg.udg.mx/PDFs/Folleto_DALE.pdf; http://plenia.com.mx/index.php?option=com_sobi2&sobi2Task=sobi2Details&catid=3&sobi2Id=4&Itemid=88. Both of these sites show their sources to be U.S. institutions, which would mean they are translations.

 

Here is an example of a posting on “ataque cerebral” that seems to have been written in Mexico: http://www.fahorro.com.mx/guia1.php?id=26.

Many sites that seem to originate outside of the U.S. post content originally from the U.S. or from other Spanish-speaking countries. In addition to looking at the site name, host, authors, and bibliography (if available), it helps to check for local linguistic usage in the text to make sure it is not a translation or a text from Spain posted in Mexico.

As mentioned in step 2 above, you can conduct these searches to find definitions of the target terms in the target language. To check for register within a dialect you have to further analyze your search results and identify materials addressed to patients as opposed to scholarly publications.

 

A word about Google counts: Be aware that Google counts should not be the sole indicator of which term is more widely accepted or should be used. Firstly, your counts might vary even if running identical searches back to back. Also, a single term might show a high count because it is used in many different senses, and you might need to add another word to narrow the search and rule out uses that are not applicable. You might consider taking the free online class Power Searching with Google to increase your search engine skills.

Bear in mind that though usage can be an indicator, there might be bad translations that are more widely used than some better options, and you might need to choose the less popular one. Usually, it is better to choose a translation that is more widely used. However, there might be cases where the equivalents in use are only known amongst interpreters and translators, as a result of a first literal or suboptimal translation, and not particularly effective with the target audience, as verified by an audience check (see step 7 below).  An example that comes to mind is the translation of “Advanced Directives,” which is a U.S. concept.  Though you might find plenty of hits for different translations of it in Spanish, none might be really understood or clear to the patients unless they came in contact with translations or interpreters using that term.  The same could happen with a technical term in a given field, that might be used outside the U.S. by a few people in that field, but not have been broadly accepted yet.    

Step 5: Consult Navarro’s Dictionary and Termium!  

The fifth (or should we say first?) step, if you are translating or interpreting into Spanish, is to consult Navarro’s Diccionario crítico de dudas inglés – español de medicina, 2da. edición (2005). His entry on stroke is one of the best:

1. [Neur.] Forma abreviada de apoplectic stroke. Los neurólogos siguen dudando a la hora de traducir esta palabra inglesa, stroke, que es una de las más utilizadas en neurología. En los hospitales españoles suele traducirse por “ictus” (forma coloquial y abreviada de “ictus apoplético”), que es sin duda un término poco preciso y, lo que es peor, poco conocido entre el resto de la población (en una encuesta efectuada en España el 1 de junio de 1999, el 95% de los encuestados no sabían qué es un ictus, pero el 92% sabían de qué les estaban hablando si se utilizaban otros sinónimos, como “embolia cerebral,” “derrame cerebral” o “infarto cerebral”). En ausencia de un diagnóstico más preciso, algunos abogan por la expresión más descriptiva “accidente cerebrovascular” (nunca “accidente cerebrovascular agudo” o “ACVA” que es un pleonasmo, puesto que, por definición, no existen los accidentes crónicos > ACUTE CEREBROVASCULAR ACCIDENT). Otra posibilidad, sin duda más apropiada para el lenguaje médico hablado, es recurrir a la forma clásica “apoplejía” que había caído en desuso.

La expresión little stroke corresponde al llamado “accidente isquémico transitorio”: la expresión complete stroke corresponde a lo que nosotros llamamos “infarto cerebral.”

2. [Card.] Pulsación, latido. stroke output o stroke volume (volumen sistólico)

.... (Navarro, 2005)

Navarro seems to indicate that the best option might be to resort to using the term “apoplexy,” which he indicates had fallen out of use. Navarro does mention another term that I have found only on the web and in Mosby, used mostly in Spain. The term is “ictus,” and he suggests that it is a term not understood by most people. If you do a Google count comparison on ictus, you might find it used more often than expected in Mexico, but a closer look at the use would indicate that the target audience might be health professionals and not patients. I suspect that the high usage found in Mexico could have two sources: reading materials from Spain, and translating English texts using Mosby or Stedman as their guide.

Navarro does also mention the term “infarto cerebral” as an equivalent of “complete stroke.” It is worth noting that my recollection of the use of “infarto” in Argentina matches the note included in the DRAE, where it says that “infarto” by itself is used mainly (“por antonomasia”) for a heart attack. However, in conducting a Google search, I was surprised at the high number of hits found in Mexico, where is it seems to be more widely used than “ataque cerebral” and is definitely worth considering, at least for some kinds of stroke:

“infarto cerebral” site: .mx 47,100; .pr: 88; .cu=10,500; .cr=753; .co=191,000; .es=706,000; .ar= 9,450. General hits=723,000.

When checking each target term, it is good to go back and check the English definition of the cognates, as suggested in step 2 above. In the case of “infarto,” here’s the definition of “infarction” in English:  “The formation of an infarct, an area of tissue death, due to a local lack of oxygen.” This is actually more than a temporary lack of blood flow; this more permanent damage caused by tissue death is unique to only some kinds or stages of strokes, and is not applicable to all circumstances. This can be corroborated by looking at eCIEMaps v.1.1.0, where, in the section for conditions of the circulatory system (section 7, codes 390-459), embolic and thrombotic strokes can be coded as occurring with or without infarction, such that a cerebral embolism without mention of infarction is coded as 434.10, while a cerebral embolism with infarction is coded as 434.11.

If you have Navarro’s dictionary, you might consult it first and think you could bypass some of the steps above. However, as good as this dictionary is, the author is not necessarily translating or interpreting for the same target audience. Or, he might not have included a term that you are looking for in his research. Even if you end up agreeing with his recommendation, you will be better prepared to defend your choice if you’ve followed some of the steps above, rather than simply quoting one dictionary. And for some terms, as in the case of stroke, he might not have a strong recommendation, given the complexities of the term.

In addition to Navarro, and especially for those working with French, another excellent source is Termium (which also has Spanish and Portuguese). Here is the link to the entry for stroke.

When you look at the entry, you will see each equivalent term, with its own source. As you scroll down the page, you will find a definition that applies to all the terms listed above. You will notice that though the source for the English is Mosby, the source for the Spanish is not the Spanish translation of Mosby, but a scholarly work on the subject, originally written in Spanish. Using Termium might be a very good choice in step 2 above. Though overall you can trust that step 3 will not be an issue, because the only equivalents listed are broad in scope and neither “derrame cerebral” nor “embolia” are listed, you would still have to follow step 4 above and verify usage and register for your particular target audience.

It is worth noting that Termium has an English entry for “embolism,” translated as “embolia,” and another one for “hemorrhage,” translated as “hemorragia,” but they do not have an entry for “derrame cerebral.” The closest match is “derrame” that is translated as “effusion.” If you look up “derrame cerebral” in the eCIEMaps, the index will point you to code 348.5, which is the code for “edema cerebral,” i.e., an accumulation of water in the brain, which is another topic entirely.

Step 6: Check Other Translated Materials

The sixth step (which can also be performed as a first step) is to look at other translations written for the U.S. Spanish-speaking audience.

More than 10 years ago, I found the term “ataque cerebral” as a translation of “brain attack” in Spanish materials published by the American Heart Association. You can also look at the translations used in Medline and other well-respected bilingual websites in the U.S. Remember that just because a site is reputed for its information in English, the translations are not equally reliable. I have examples of several reputable English sources that translate “stroke” as “derrame cerebral.” In one case, I contacted the person in charge of managing the terminology on the translations for the site. It seemed as though part of the problem could have been the reliance on a translation memory (TM). Using a more precise match with respect to scope can make the TM much more accurate and useful.

Beyond Medline, this is a very interesting site when it comes to “stroke”: In the English, they do not mention a “CVA” but only mention “brain attack” as another name for stroke. In the Spanish, they translate “stroke” as “ataque cerebral” or the equivalent of “CVA” interchangeably. The whole Spanish page looks much more like a localization of the explanation of stroke than a translation. And they seem to have opted for “accidente cerebrovascular” and for “ataque cerebral” as the two most appropriate equivalents.

The choice in Spanish of “accidente cerebrovascular” and “ataque cerebral” seems quite interesting. Though many medical interpreters keep saying that our patients will not understand certain terminology, in general, even people with very little formal education in Spanish, from small towns, will often speak in “bigger words” than college graduates from the United States. This is because the media and culture in general tend to speak in higher-register terms. Therefore, when comparing registers, what might seem like a very high register in American English might not be so in Spanish (or another target language).

Still, there are patients who might not understand “accidente cerebrovascular” and others who might think that “ataque cerebral” is an epileptic attack.

Step 7: Choose an Equivalent for Your Audience

The last step is to choose an equivalent for your audience. When I’ve tried just using “ataque cerebral” by itself, as the translation of the AHA’s more recent low-register term for stroke, I’ve noticed that some patients and interpreters think more of a seizure than of a stroke. So, though the term “brain attack” might work in English, where people might not necessarily refer to a seizure as an “attack,” in Spanish it seems that “attack” is used a lot for epilepsy. One option is to combine the newer superordinate term with listing some of the more familiar hyponyms, by saying: “ataque cerebral, como por ejemplo derrame o embolia.” This does have the problem of being quite long.

You could then consider some of the other shorter options. The term “apoplejía” seems too high-register for many patients, but could possibly be reintroduced, if accompanied by the examples “apoplejía, como por ejemplo derrame o embolia cerebral.” However, it would be moving in the opposite direction of the American trend, going back to a higher-register word when they are lowering the register. “Ictus,” as indicated by Navarro, is not understood by most lay people, and its use seems to be restricted mostly to Spain. If used in other countries, it seems to be more restricted to healthcare professionals.

With all this considered, I now lean towards using “accidente cerebrovascular” as the translation of both “stroke” and “CVA,” and “ataque cerebral” as the translation of “brain attack,” possibly including the use of “accidente cerebrovascular” somewhere in the text, as used in the www.stroke.org page quoted above. In either case, I would probably still add, at least in the first instance, “como por ejemplo embolia o derrame cerebral” (unless the context of the translation or interpreting already includes the explanation of the different types of stroke).

For medical interpreters, who are bound by their Code of Ethics to “not add, change or omit anything,” it‘s a good idea to always run this by providers for their approval. The first time, an interpreter could say, “The interpreter would like to note that he/she will translate “stroke” as “cerebrovascular accident or brain attack, such as an embolism or bleeding in the brain,” because in Spanish we do not have a term as widely understood as “stroke.” In this way, the interpreter can ensure the provider agrees with their definition “by extension” and knows the interpreter is not freely adding explanations.

A final word of caution to medical interpreters: What happens if a patient says they had an “embolia” or a “derrame cerebral”? Do you really know what he or she actually had? In my experience, you can only trust the term they give you if they had the stroke in a Spanish-speaking country and give you term that was used by the doctor there. Overall, it is better to be very cautious and intervene at this point, letting the provider know that these terms are often used interchangeably by patients, translators and interpreters, and that though the patient said “embolia” what he might actually have had was a brain hemorrhage (or vice versa). Hopefully, the patient’s medical record will then be written with an accurate diagnosis, since a term for another condition could cause problems when his or her medical records are used in the future.

Conclusion:

As medical interpreters and translators, we can’t rely solely on the recommendations of bilingual dictionaries or even experienced colleagues. Rather, we need to develop a methodology to assess recommendations in order to make an educated choice between the various options available.

To summarize, in comparing source and possible target terms, we need to:

1.       Define the source term.

2.       Research definitions of the target terms found in bilingual sources, or suggested by colleagues.

3.       Compare the scope of the source and target terms.

4.       Compare usage of target terms, particularly with respect to register and dialect.

5.       Consult reputed dictionaries that provide more than just one-to-one equivalents.

6.       Look at translations from reputable sources.

7.       Consider the target audience.

Though these steps are presented in a linear fashion, there is definitely room to go back and repeat prior steps as we find new terms throughout the process.

Something that is critical when undertaking such detailed work on a single term is to make sure you document your research. At the bare minimum, you might create a folder for all the parallel texts found in the process and keep a running list of everything you’ve found in some kind of Word table or spreadsheet. I have a simple table format I’ve used for many years, especially on interpreting assignments, in which I make sure I separate source terms, target terms (from parallel documents) and translation terms (equivalents chosen by other translators or suggested in dictionaries) into separate columns, making sure there is only one concept per row, which can then be imported into a terminology database. You may look at Donna Furlani’s articles on Terminology for further tips on documenting your search in Excel.

It is not always feasible to invest this amount of time on each term you deal with regularly, but I would suggest that you take a look at the performance improvement criteria used in many hospitals, and start checking the reliability of your equivalents based on which one you use more often, poses higher risks, or may involve higher cost (perhaps, by leading the doctor to run unnecessary tests). I hope you enjoy the treasures you will find as you try this research process with “stroke” or other terms.

Baker, Mona. 2011. In Other Words. 2nd. New York : Routledge, 2011. 332 pages.

Navarro, Fernando A. 2005. Diccionario crítico de dudas inglés - español de medicina. 2nd. Aravaca (Madrid) : McGraw-Hill - Interamericana, 2005. ISBN 978-84-481-9808-4.*

Helpful Links:

http://www.termiumplus.gc.ca/tpv2alpha/alpha-eng.html?lang=eng&i=&index=ent&__index=ent&srchtxt=stroke&comencsrch.x=0&comencsrch.y=0

http://icd9cm.chrisendres.com/index.php?action=search&srchtype=mesh&srchtext=cerebrovascular%20accident

http://eciemaps.mspsi.es/ecieMaps/browser/index_9_2012.html#search=444.9&index=enf&searchId=1362860509845&historyIndex=4

* If you don’t own Navarro, make sure you compare prices with InTrans Book Service, since an Amazon search might only render exorbitant prices. However, if you can’t afford it individually, consider having your hospital, agency, or local library purchase it as a reference book.