Article Cite This: J. Chem. Educ. XXXX, XXX, XXX−XXX
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Identifying Relevant Acid−Base Topics in the Context of a Prenursing Chemistry Course To Better Align Health-Related Instruction and Assessment Corina E. Brown,*,† Melissa L. M. Henry,‡ and Richard M. Hyslop† †
Department of Chemistry and Biochemistry, University of Northern Colorado, Greeley, Colorado 80639, United States School of Nursing, University of Northern Colorado, Greeley, Colorado 80639, United States
‡
S Supporting Information *
ABSTRACT: This study explores the acid−base topic in the context of a chemistry course taken as a prerequisite for a baccalaureate nursing program. Core findings were derived from semistructured interviews with experts in the areas of chemistry and nursing, and a multiple university survey of experts’ opinions. The acid−base topic was reviewed and evaluated in several general, organic, and biological (GOB) chemistry textbooks and nursing textbooks. A set of acid−base chemistry concepts were identified that have relevance in the allied-health fields, especially nursing. By being aware of these concepts, the GOB chemistry instructors can better plan their learning activities, teaching strategies, and assessment. KEYWORDS: Chemical Education Research, First-Year Undergraduate/General, Interdisciplinary/Multidisciplinary, Acids/Bases, Curriculum, Nonmajor Courses, pH FEATURE: Chemical Education Research
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INTRODUCTION In October 2010, the Institute of Medicine released its landmark report on The Future of Nursing, which called for increasing the number of baccalaureate prepared nurses in the workforce to 80% and doubling the population of nurses with doctoral degrees1 to meet the demands of increasingly complex patient care. Due to the increased expectations of nursing as a profession, the need for a strong scientific foundation is imperative. Despite the need for more knowledge in science, the nursing education literature demonstrates that the level of science knowledge is far from being fulfilled.2,3 In order to achieve these higher standards and to reduce the cognitive load in these courses, it is imperative to establish a strong, foundational level of basic knowledge in the nursing prerequisite science courses by focusing on the topics that are central to the profession of nursing.4,5 In a previous study,6 the general, organic, and biological (GOB) chemistry topics pertinent to nursing clinical practice were identified. Among these, the acid−base topic showed complete agreement among the experts (GOB chemistry educators, nurse educators, and nurses) as being a topic relevant to clinical practice. Students have difficulty with different concepts of acid−base chemistry despite the centrality of acid−base reactions in chemistry as well as the prevalence of acid−base reactions in a biological system. Numerous studies have explored the students’ difficulty with acid−base chemistry © XXXX American Chemical Society and Division of Chemical Education, Inc.
at different levels including high-school chemistry, general chemistry, organic chemistry, and graduate-level chemistry.7−15 Additionally, some studies specifically presented the struggle students have with the understanding of pH and buffers.16,17 However, due to the importance and relevance of the topic in the allied-health fields, there is a need for exploration of this topic in the context of a nursing chemistry course. Training in the undergraduate years is very important in helping nursing students become well-rooted in content knowledge so they have a strong foundation when they become active in the clinical arena.2 The goal of this study was to identify acid−base concepts from a GOB chemistry course that are relevant to the clinical practice of nurses. Although the target audience in the current study pertains primarily to prenursing students, the results may relate to all areas of the allied-health profession majors requiring the GOB chemistry course as a requirement of their major. Therefore, it would be beneficial to the students for instructors to use terminology and examples that are appropriate for the future professional goals of the student population of the course. Received: October 30, 2017 Revised: March 23, 2018
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DOI: 10.1021/acs.jchemed.7b00830 J. Chem. Educ. XXXX, XXX, XXX−XXX
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were assessed through a qualitative methodology18 in the form of open-ended interviews, and as part of a survey. On the basis of the Stoker GOB chemistry textbook,19 a list of concepts was developed. The final list was compared to the tables of contents of several other GOB chemistry textbooks,20−27 given in the Supporting Information. This list of acid−base chemistry concepts (pH concept; Ka, pKa method expressing acid strength; buffers; acid−base neutralization) was presented to the experts during a scheduled interview. The experts were requested to discuss the relevancy and the applicability of the different concepts based on a protocol presented in the Supporting Information. In addition to the interviews, an online survey was designed to explore the nursing and chemistry experts’ opinions, from multiple universities across the United States, about the acid− base chemistry concepts perceived to be relevant to nursing clinical practice. The survey was developed by the researchers after the interviews were completed. The survey was administered online by using the university survey software Qualtrics. The experts received an invitation via email to participate in the study. Also, in the email, the purpose of the research was explained (Supporting Information). Invitations to participate were sent by email to the experts. The email informed the experts about the project. The participants were advised to use the link provided to accesses the survey. The survey opened with an informed consent statement and a request for acknowledgment of that statement (Supporting Information). The survey presented the acid−base concepts typically taught in a GOB chemistry course, and respondents were asked to rate each concept as important (the concept has a direct application to clinical nursing practice), foundational (the concept facilitates the understanding of an important concept), or not important (the concept does not have a direct application or is not significant in nursing clinical practice). These three categories were developed through the initial interviews with nursing and chemistry experts. The meaning of each of these terms was explained in the informative email (Supporting Information). Following each item, the survey presented an open text box for an application and/or comments. Concepts deemed foundational or important were considered relevant to nursing practice. A total of 264 nurse educators (response rate of 26.2%) and 16 GOB chemistry instructors (response rate of 23.1%) participated in the survey. The second part of the study compared and contrasted the acid−base chemistry concepts covered in a variety of commonly used GOB chemistry and nursing textbooks that are in current use. The acid−base chemistry topics were summarized in a table (see Supporting Information) for simple content analysis exploring similarities and differences in presentation and content.
METHODOLOGY
Purpose and Research Questions
The focus of this research study was an undergraduate course that covers a broad range of topics in GOB chemistry at a midsize, western U.S., state university with a nursing program leading to a B.S. in Nursing. The GOB chemistry course at this institution is taught as a one-semester, three-credit hour lecture, 1 h recitation, and a one-credit hour laboratory with a recommended prerequisite four-credit hour introductory general chemistry course. The GOB chemistry course is a requirement for the acceptance into the Nursing program. The students in the course were allied-health majors, primarily nursing. The purpose of this study was to investigate which of the acid−base concepts are considered relevant to nursing and should be taught in a GOB chemistry course as framed by the following research questions (RQs): • RQ1: What are the acid−base concepts in a GOB chemistry course that are perceived by experts to be relevant to nursing clinical practice? • RQ2: How and what acid−base concepts are covered in the GOB chemistry and nursing textbooks? Participants
All ethical considerations common to research with human subjects were used in the development of this study. Prior to all phases, data collection and analysis protocols, as well as security protocols, were reviewed and approved by the University Institutional Review Board. Participation in the study was voluntary. Participants were recruited on the basis of one of the following: their academic expertise in the field of nursing, experience in clinical practice, or experience teaching a GOB chemistry course to prenursing students as previously described.6 Diversity in sample selection provided a greater range of opinions and different perspectives of the phenomenon. For the open-ended interviews, all experts were recruited from a midsize, western U.S., state university. Chemistry faculty were members of a Department of Chemistry and Biochemistry; nurse educators and nursing graduate students were members of a School of Nursing. In the open-ended interviews, four chemistry instructors, eight nurse educators, and four nursing graduate students participated. There was adequate time spent in data collection such that data became “saturated”; that is, no new information was revealed in the analysis. Data saturation is reached when further coding does not reveal new information. For the survey, the nurse educators were identified and recruited using the Web sites of different nursing schools. In the survey, we did not differentiate between nurse educators and nursing graduate students. The GOB chemistry instructors were identified and recruited using the Web sites of chemistry departments at universities that have a nursing school, since it was assumed that the GOB chemistry course curriculum at these universities was considered appropriate by the corresponding nursing schools.
Data Analysis
The researchers were the primary instruments for data collection and analysis of the interviews. The interview transcripts were analyzed for common themes regarding the concepts presented to the experts. On the basis of terminology used by the experts to indicate the importance of a particular concept, the concept was placed in one of the three categories: important, foundational, or not important as previously described.6 The researchers independently coded a random sample of three transcripts. The researchers compared their codes to ensure consistency in the coding system. Two additional raters
Data Collection
The research was conducted in several stages and used a multimethods approach for data collection. The first part of the study sought to identify the main acid−base GOB chemistry concepts perceived by nursing and chemistry experts to be relevant to nursing clinical practice. The opinions of the experts B
DOI: 10.1021/acs.jchemed.7b00830 J. Chem. Educ. XXXX, XXX, XXX−XXX
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Table 1. Distribution of Experts Regarding the Importance of Acid−Base Chemistry Conceptsa Acid−Base Concepts pH concept Ka, pKa method expressing acid strength Buffers Acid−base neutralization
Expertsb CI NE, CI NE, CI NE, CI NE,
NGS NGS NGS NGS
Important, %c
Foundational, %
Not Important, %
100 100 50 50 75 75 50 50
0 0 25 33 25 25 25 33
0 0 25 17 0 0 25 17
a
Data collected via open-ended interviews. bCI, chemistry instructors (N = 4); NE, nurse educators (N = 8); NGS, nursing graduate students (N = 4). cPercentage of total of respondents.
Table 2. Distribution of Experts’ Opinions Regarding the Importance of Acid−Base Chemistry Concepts from Multiple Universities Acid−Base Concepts pH concept Ka, pKa method expressing acid strength Buffers Acid−base neutralization a
Expertsa
Important, %b
Foundational, %
Not Important, %
CI NE CI NE CI NE CI NE
88 87 38 49 75 75 56 64
12 13 37 36 25 25 13 31
0 0 25 15 0 0 31 5
CI, chemistry instructors (N = 16); NE, nurse educators (N = 264). bPercentage of total of respondents.
terminology used and/or if they need clarification. Also, a GOB chemistry textbook was available for them to consult. For example, in the interviews one of the nursing graduate student mentioned: In my chemistry class and we did all kinds of calculations, buffers calculations by using Ka and pKa, in nursing we use the concept in pharmacology. [Nursing Graduate Student 002] This reflects an understanding of the terminology. The experts were in agreement regarding the ranking of the four concepts. Results from the interviews with nursing and chemistry experts are presented in Table 1. In the survey, the experts were required to express their opinion regarding the concept of pH, Ka and pKa, buffers, and acid−base neutralization. Also, they were asked to comment and provide applications of the concepts and were given the possibility to add new concepts if they were considered them to be important/foundational for the acid−base chemistry topic. The survey data were analyzed on the basis of the answers’ percent distribution in one of the three categories as presented by Qualtrics. Most of the chemistry instructors and nurse educators considered each of the four concepts relevant, with a minimum of approximately 70% of the experts in each group indicating the concepts are at minimal foundational and thus relevant to nursing practice. Data are presented in the form of percentage of agreement among the experts based on the different concepts (Table 2). The data from the open-ended interviews and the survey are following similar trends. The chemistry instructors and nurse educators who participated in the survey were in agreement with the foundational/important classification of the concepts of pH and buffers. Regarding the importance of Ka/pKa and acid−base neutralization, there appeared to be some discrepancy between the opinions of the two groups of experts regarding the importance of these two concepts. A higher
were consulted, and their coding was in complete agreement with the coding description developed. Data from interviews of the experts at the researchers’ university were tabulated and compared for consensus both within each group of experts and between groups of experts. The data from both interview transcripts and the survey were analyzed in terms of the applications mentioned or provided by the experts and special comments that are presented in the form of quotes. A summary of the quotes analysis and selected quotes are presented in the Supporting Information. Several commonly used nursing textbooks of medical− surgical,28,29 pathophysiology,30 and pharmacology31−33 as well as several GOB chemistry textbooks19−27 were explored for how each discipline generally presents acid−base topics. Each textbook’s table of contents and index were reviewed, and pages were identified in which acid−base balance content was presented. The identified textbook sections were then reviewed and summarized in table format. General content analysis of the textbooks allowed exploration and comparison of the concepts in terms of coverage, presentation, and application of the acid− base chemistry concepts between the two disciplines. The researchers independently coded a random subsample of textbooks and then compared their findings to ensure consistency in the coding system. The codes were identical in over 95% of cases. Each researcher reviewed all the textbooks in both categories. Details of the analysis can be found in the Supporting Information.
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RESULTS Information from the open-ended interviews was used to formulate the questions for the survey. In order to ensure that the experts, especially the nurse educators and nurses, understand the questions in the same way as the chemistry instructors do, in the think-aloud protocol the nursing educators and nurses were asked if they understand the C
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Table 3. Summary of Acid−Base Chemistry Content in Nursing and GOB Chemistry Textbooks Acid−Base Content Area
GOB Chemistry Booksa
Basic definition Acid examples Base examples Familiar examples of acid and bases pH
Arrhenius and Brønsted−Lowry HCl, HNO3, H2SO4, H2CO3, acetic acid NaOH, NH3 Common household products Presentation of common household’s products; some texts present the pH of blood Scale of different pH values General equilibrium, function of buffers from the perspective of general chemistry
Brønsted−Lowry H2CO3, lactic acid, NH4+ HCO3−, lactate, NH3 Body fluids Discussion of pH of blood and other body fluids (GI tract, urine)
Given in general terms and examples
Related to pharmacology: absorption, excretion of drugs
General acid−base equilibrium and the effects of buffers Many textbooks present carbonic acid, acetic acid and ammonium ion Quantitative aspects (algorithmic) pH calculations Henderson−Hasselbalch equation
Effect of metabolic acid production and need for mechanisms to control pH (buffers, respiratory and renal systems) to maintain balance
Visual aids of pH Buffers, imbalances Respiratory/metabolic Acidosis/alkalosis Ka, pKa, predominant forms of the compounds at a given pH Focus
Approach
Nursing Textbooksa
Others a
“Teeter-totter” analogy Function of buffers (carbonate, phosphate, protein) explained in connection with these physiological conditions
Qualitative aspects Conceptual Values in and out of a range How to interpret arterial blood gases
The Supporting Information provides references for this table.
equivalent of a teeter-totter, a balance, or an elevator in the nursing textbooks. GOB chemistry textbooks emphasized a more quantitative, mathematical approach to buffers and the Henderson− Hasselbalch equation, whereas nursing textbooks took a qualitative approach. This could account for the difference between the chemistry instructors and nurse educators in ranking the importance of pKa, acid strength, and neutralization concepts listed in Table 2. What was very interesting for the researchers to observe was the approach used in the two disciplines’ textbooks. For example, a qualitative understanding of buffers and the effect of acid−base concentration on pH and, consequently, understanding the effect of pH on the biochemistry and physiology of the patient is perhaps more important to nursing practice than being able to calculate the pH of a solution with given concentrations of a weak acid and its conjugate base.
percentage of chemistry instructors considered these concepts not important, whereas a higher percentage of nurse educators considered them important. The reasoning behind the classification by the chemistry instructors and nurse educators was investigated using the think-aloud protocols transcripts and comments from the survey. The GOB chemistry instructors commented on the fact that these concepts are too “mathematical”, whereas many of the nurse educators mentioned the importance of Ka and pKa in pharmacology. Caution should be exercised in interpreting the significance of what appears to be a discrepancy. Acid−Base Chemistry Concepts Presented in GOB Chemistry and Nursing Textbooks
The researchers reviewed the selected Nursing and GOB Chemistry textbooks. The presentation and approach of the acid−base concepts in the nursing textbooks were summarized and compared with the presentation and approach in the GOB Chemistry textbooks. As researchers discussed and compared their personal notes they made in reviewing the textbooks, similarities and differences were noticed in the presentation of the topics in the textbooks from the two disciplines. From this analysis, several categories emerged as presented in Table 3. It is beneficial that the GOB chemistry instructors be cognizant of how nurse educators approach these same topics in ways slightly different, but perhaps more appropriate, than chemistry instructors. The GOB chemistry textbooks generally mentioned nitric and sulfuric acids and sodium hydroxide as acid−base examples; however, these have little to no direct application to nursing practice. The nursing textbooks in general mentioned more biologically relevant acids−bases such as carbonic acid, lactic acid, ammonium ion, ammonia, and bicarbonate ion as examples of acids and bases. The concept of pH is greatly emphasized in both disciplines of textbooks also with a mathematical presentation in the GOB chemistry textbooks. The visual aids used in the textbooks to represent pH were always a horizontal or vertical scale of pH in the GOB chemistry textbooks and the
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DISCUSSION
On the basis of the analysis of textbooks, interviews, and the survey of the nursing and GOB chemistry experts, a list of recommended learning outcomes for the acid−base topic was formulated and is presented here. • Definition: Identify an acid and base according to the Brønsted−Lowry definition; Demonstrate knowledge of their source in a biological system • pH: Define, explain, and apply the relationship between pH and acid−base properties of a compound/environment, including the meaning of acidosis/alkalosis • Buffer: Identify the acid−base and conjugate base−acid; Explain, predict, and apply the relationship between the function of a buffer and the pH variation, phosphates, proteins (e.g., hemoglobin, albumin), andbicarbonate− carbonic acid (e.g.: CO2 + H2O ⇌ H2CO3 ⇌ HCO3− + H+) • Ka, pKa: Evaluate the strength of an acid based on the Ka or pKa values; Predict the direction of an acid−base D
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values. According to the nurse educators, nursing students will learn the details of this assessment and the interpretation of ABG values in a nursing program. In a GOB chemistry course, students should become familiar with the concept of pH and partial pressure (partial pressure of carbon dioxide, PaCO2) and understand the function of a buffer (bicarbonate buffering system, H2CO3/HCO3−). It was interesting to note the nursing educator’s perspective on buffers as expressed through the following comment: When it comes to acids and bases, the difference between life and death is balance. The body’s acid−base balance depends on some delicately balanced chemical reactions. The hydrogen ion affects pH, and pH regulation influences the speed of cellular reactions, cell function, cell permeability, and the very integrity of cell structure. [Nurse Educator 112] It is important for students to understand what an acid−base pair is and how the relative concentrations of each affect the pH of an aqueous solution. Several nurse educators mentioned the three primary systems that regulate the pH of various bodily fluids and maintain the acid−base balance: chemical buffers, the respiratory system, and the renal system and their emphasis through the nursing textbooks.28−30 Another important concept for students to learn in a GOB chemistry course is the role of a buffer as a substance that combines with excess acid or base and acts immediately to maintain a somewhat constant pH. Buffers are the body’s most efficient pH-balancing force. Some of the nurse educators and chemistry instructors mentioned that the main chemical buffers are bicarbonate, phosphate, and protein. These buffers appear in blood, intracellular fluid, and extracellular fluid. Examples of biological buffers such as phosphate or bicarbonate and how they work could be used frequently in GOB chemistry textbooks as well as in lecture to stress the relevance and importance of buffers in addition to the origin of the specific acids and bases affecting pH. The concept of Ka and pKa along with the Henderson− Hasselbalch equation is mentioned in some of the pharmacology textbooks with regard to drug absorption and distribution which was as also mentioned by the nurse educators: When I think about pharmacology, pH becomes important for the dissociation of some meds in particular body fluids. [Nurse Educator 003] Some of the nurse educators expect students to be able to use the Henderson−Hasselbalch equation in pharmacology in determining the site of absorption of different drugs. Ka and pKa are not concepts that a nurse typically uses in the daily routine; however, according to some of the nurses, it is important to expose the students in the GOB chemistry course to the main acid−base concepts particularly since some of them may choose to go into a graduate nursing program. The concept of acid−base neutralization is important in order to understand for example the mode of action of a buffer: excess H+ from metabolism is neutralized by the action of the buffer component. Several chemistry instructors and nurse educators mentioned as an example the neutralization effect of certain medications such as an antacid (for example, neutralization of hydrochloric acid in the stomach). The quantitative aspect of a titration (other than dosage of medication) is not directly applicable to nursing practice, and the quantitative aspects of titrations are more applicable to the clinical lab. As an example of qualitative aspects of titrations, the acidity of urine that is determined through a titration and the relevance to diagnosis may be mentioned. Excessive acidity
equilibrium as influenced by pH; Identify the predominant form of a compound at a given pH • Explain and apply qualitative and quantitative aspects of acid−base neutralization The acid−base balance provides important information in nursing practice.28−30 In order to assess an acid−base balance, it is important to understand how the hydrogen ion concentration affects weak acids, weak bases, and pH. Some suggested approaches are given to facilitate the achievement of the learning outcomes for the concepts. In the introduction of acids and bases, a discussion of sources of H+ ion that contribute to pH in a biological system would be beneficial for our students. Even though the students may not have the knowledge at this point about all the details of metabolism, we can still mention some of the metabolic processes and offer the students an idea for how this topic integrates with other material presented in the course. The following could be mentioned: aerobic respiration generates carbon dioxide and thus carbonic acid; anaerobic respiration produces lactic acid; ketogenesis produces ketone bodies which are weak acids; hydrolysis of phosphoproteins and nucleic acids produces phosphoric acid. Several bases and their sources can be mentioned. Bicarbonate ion (HCO3−) is one of the most important bases in the human body and neutralizes acids in the blood, acting as a buffer. Ammonia, another base in the human body, is generated from the metabolism of amino acids. Basic amino acids present another important source of bases. One of the nurse educators commented on the importance of the fundamental understanding of acids and bases, and their relationship to pH and diagnosis: You need to have a basic understanding of the difference between a base and an acid as these things do come up in nursing. It will help you understand how it is that some medications are more readily absorbed than others in the body. pH is a concept that comes up in urinalysis, blood work and blood gases. Understanding what makes an acid and what makes a base and how they affect liquids and tissue are extremely important. [Nurse Educator 003] For certain enzymes, cell function, and normal metabolism, the blood pH must remain slightly alkaline, in the narrow range 7.35−7.45. A blood pH below 6.8 or above 7.8 is usually fatal.34 Nurse educators and chemistry instructors mentioned that the regulation of pH depends on the necessities of each organ or tissue and is extremely important for an organism since enzymes are optimally functional only within certain pH ranges; thus, biochemical reactions depend on the presence of correct pH levels. In the pH concept is also reflected the balance between the concentration of hydrogen ion and the concentration of bicarbonate ion ([HCO3−]). Generally, pH is maintained by a ratio of 20 parts HCO3− to 1 part H2CO3. This number is well-known among the nurses, but very few of them know its origin.35 A GOB chemistry course can show the application of the Henderson−Hasselbalch equation to relate the pH of blood to constituents of the bicarbonate buffering system and the way this ratio is calculated. Understanding acidosis and alkalosis in terms of definitions is important. In acidosis, the blood has too much acid (or too little base). In alkalosis, the blood has too much base (or too little acid). Students will be taught the cause and the treatment of these conditions in the nursing program. Another application of acid−base chemistry mentioned by the nurses was the interpretation of arterial blood gas (ABG) E
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Figure 1. Acid−base chemistry applicability and integration.
Although many of the GOB chemistry textbooks provide students with examples of the uses for acid−base chemistry, GOB chemistry instructors may present this material from the perspective of general chemistry with few if any applications to nursing; consequently, the students may consider the information irrelevant to their future profession. At the other extreme, teaching the chemistry with too much emphasis on the applications could be detrimental on the basis of the advice of nurse educators; students may remember the “story” but not the concept. The students should be exposed to numbers and some of the quantitative aspects of the topic along with the relevance to nursing, but the assessment and the interpretation should be left for the nurse educators to teach. Also, at the advice of nurse educators, the students in a GOB chemistry course should be exposed to the basics of chemistry so that they can understand the basics of nursing when exposed to nursing classes. From the interviews and the survey, experts commented on several areas of application and integrative teaching approaches of the acid−base concepts as summarized in Figure 1. Even though the acid−base topic is introduced in each of the textbooks in a certain chapter; it may be revisited throughout the course especially in connection with biomolecules and metabolism. In the presentation of different acid−base concepts, the GOB chemistry instructor may show students the impact and the importance of acid−base chemistry and integration of the concepts with other important aspects such as the Bohr effect known by the nurses as oxygen perfusion. The absorption, distribution, metabolism, excretion, and pharmacology of different drugs are profoundly affected by the ionic state of compounds under varying pH conditions. Amino acids and proteins are important buffering systems, and their function is greatly affected by acid−base conditions of the environment since they can exist in different ionized forms. The proper function of enzymes is important for many metabolic reactions. Ultimately many metabolic reactions can be affected by certain levels of acidity. Increased levels of ketone bodies (ketoacidosis) represent an important metabolic condition related to acid−base and electrolyte balance. It is worth mentioning that, in the interviews and the survey, many nurse educators mentioned in connection with acid−base
of the urine may provide information about the state of a ketoacidosis. An example that involves several of the aforementioned concepts of acid−base chemistry can be used in the discussion of the process of digestion. Every time we digest food, acids and bases are at work in our digestive system. The acidic environment of the stomach helps with the digestion of food. The enzyme pepsin, which helps hydrolyze proteins in the stomach, can function optimally only in the low pH environment. The stomach secretes a strong acid (HCl) that allows pepsin to work. However, when stomach contents enter the small intestine, the acid must be neutralized. This is because enzymes in the small intestine need a less acidic environment in order to function. The pancreas secretes a weak base (NaHCO3) into the small intestine, and this base neutralizes the hydrochloric acid from the stomach.
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CONCLUSIONS AND IMPLICATIONS FOR TEACHING Through this study, the acid−base chemistry concepts relevant to nursing practice were determined to be the Brønsted−Lowry definition, pH, buffers, acid strength, and to a lesser extent neutralization, with examples provided by chemistry instructors and nurse educators of how they pertain to nursing education and practice. According to interviews of the nursing experts, many critical illnesses can disrupt a patient’s acid−base balance, and a disturbance in acid−base equilibrium may indicate other underlying diseases or organ damage. An important aspect of accurately interpreting acid−base balance requires a good understanding of the chemistry and the ability to combine the information with knowledge of compensatory physiological mechanisms which the students will learn in pathophysiology. An outcome-based approach to teaching and learning focuses on what the student knows and can do after instruction. Because perceived relevancy plays an important role in the process of meaningful learning,36,37 it is essential that instructors make every effort to highlight the vital role that acid−base chemistry plays by providing students with examples from many different contexts including chemistry, biology, and nursing. F
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disorders the management of electrolytes. Thus, besides teaching acid−base chemistry, it is important for a GOB chemistry instructor to take some time to relate the topic to electrolytes, for example, the effect of ketosis on the excretion of electrolytes. Limitation of the Study
The GOB chemistry course at some universities may have other majors besides the prenursing students such as biology or sports and exercise science. The results presented here pertain mainly to the allied-health majors. In addition, it should be mentioned that, as a general observation through the interviews and survey, some of the chemistry instructors commented that even though they understand the implication of different acid−base topics, they do not know the details and the relevance of the topics to the clinical practice. We have attempted to express the opinions of nurse educators regarding the significance and the applications of the acid/base topics in the article. Given the typical population of students in a GOB chemistry course, it would be helpful for GOB chemistry instructors to better understand the purpose and the implications of the chemistry course in the preparation of allied-health students. It is essential that a dialogue exist among those involved in the education of allied-health students so that the GOB chemistry content can be brought into better alignment with what the allied-health professional schools expect students to learn from the GOB chemistry course.
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ASSOCIATED CONTENT
* Supporting Information S
The Supporting Information is available on the ACS Publications website at DOI: 10.1021/acs.jchemed.7b00830. Interview protocol used in data collection, analysis of open-ended interviews, acid−base chemistry concepts covered in the GOB chemistry and nursing textbooks analyzed, and analysis of nursing experts’ comments (PDF, DOCX)
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AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. ORCID
Corina E. Brown: 0000-0002-2368-6733 Notes
The authors declare no competing financial interest.
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REFERENCES
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DOI: 10.1021/acs.jchemed.7b00830 J. Chem. Educ. XXXX, XXX, XXX−XXX
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DOI: 10.1021/acs.jchemed.7b00830 J. Chem. Educ. XXXX, XXX, XXX−XXX
