C H A P T E R
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The certified registered nurse anesthetist (CRNA) brings a wealth of knowledge to the clinical arena. Although this knowledge comes from a variety of disciplines, including physiology, pharma- cology, physics, nursing, medicine, and psychology, it should be appreciated that research and critical thinking first and foremost make this knowledge possible. Evidence-based practice greatly enhances credibility within the clinical setting.
Research represents a rational approach to the making of prac- tice choices among initially plausible alternatives and provides direction and a means for validating these choices. Whether selecting one intravenous opioid over another or choosing one particular pediatric induction technique instead of another, CRNAs rely on research to provide a solid foundation for clinical decision making, thereby avoiding fads and inferior alternatives.
The impact of research on the day-to-day activities of the CRNA has become an especially relevant topic. Before the mid- 1970s the vast majority of nurses functioned without much consid- eration of research or publication of their ideas. In the late 1970s we experienced a period of punctuated evolution. Major driving forces behind this evolution included movement into a graduate educational framework, a more sophisticated appreciation of the scientific underpinnings of our specialty, recognition of the impor- tance of evidence-based practice (EBP; see the discussion of this topic later in this chapter), national attention to issues of patient outcome and patient safety, and a growing self-awareness of nurse anesthetists not only as providers of excellent clinical care but also as active participants as scholars in the field.
Because CRNAs primarily function with a practice-oriented perspective, the recommendations of Brown et al1 seem especially relevant. These scholars suggested that four characteristics of research are essential for the development of a scientific knowl- edge base for a discipline such as nurse anesthesia. First, research should be actively conducted by the members of the discipline.
Second, research should be focused on clinical problems encoun- tered by members of the discipline. Third, the approach to these problems must be grounded in a conceptual framework—that is, it must be scientifically based, emphasizing selection, arrangement, and clarification of existing relationships. And finally, the meth- ods used in studying the problems must be fundamentally sound.
WAYS OF KNOWING
The term research can be broadly defined as the application of a systematic approach to the study of a problem or question. How- ever, we do not know all the things we claim to know on the basis of systematic inquiry. For example, tradition and custom are important sources of human knowledge. Those who live in the United States are raised in a democratic society and are taught that democracy is the best and most advanced form of government.
This is a powerful and efficient route for communication of knowl- edge because it excuses individuals from initiating an indepen- dent effort to come to grips with the concept of democracy. In the absence of evaluation for validity, however, such a route may lead to blind acceptance.
Another source of our knowledge is authority. We know some- thing to be true because an authoritative person such as a parent, educator, clergyman, physician, or teacher tells us it is true. Yet, despite the fact that authorities are fallible, the knowledge they pass on often remains unchallenged. Should we not ask the basis for what we are being told?
Personal experience (the trial-and-error method) represents a powerful source of knowledge. We make observations (e.g., that placing a hand on a hot stove causes a burn) and on their basis make predictions (e.g., that a stove may be hot) and future behav- ioral decisions (e.g., to avoid touching a stove). However, a risk remains: Not only are certain events perceived differently by dif- ferent people, but one person’s experience may be too narrow to serve as the basis for the development of a reasonable and unbiased understanding of a given phenomenon. Although this mechanism is a practical way of knowing, it is highly fallible and represents a coarse and inefficient way to gain knowledge.
Logical reasoning is yet another way of knowing. The reasoning method has two components: inductive reasoning and deductive reasoning. Inductive reasoning results in generalizations that are derived from specific observations. Consider the following line of reasoning using a character in many action and adventure movies, James Bond, for example. We observe that James Bond is mortal;
we observe that a number of other people are mortal as well; on this basis, we conclude that all people are mortal. Deductive reasoning is the development of specific predictions from generalities. In this case, we see the following line of reasoning: we know that all men are mortal; we know that James Bond is a man; therefore we con- clude that James Bond is mortal. Both methods are useful, but the former offers no mechanism for evaluation or self- correction, and the latter is not in itself a source of new information.
Perhaps the most advanced way of knowing is reflected in the scientific method. Although it too is fallible, the scientific method is more reliable and valid than other methods. It provides for self- evaluation with a system of checks and balances that minimizes bias and faulty reasoning. In essence, it is a systematic approach to solving problems and enhancing our understanding of phenom- ena. It has, at its foundation, the gathering and interpretation of information without prejudice.
THE NATURE OF RESEARCH
Research is by definition a dynamic phenomenon. Whether it is directed purely at the acquisition of knowledge for knowledge’s
4 Nurse Anesthesia Research
Science of an Orderly, Purposeful, and Systematic Nature
Chuck Biddle
CHAPTER 4 Nurse Anesthesia Research t 37
sake (basic research) or at the specific solution of problems (applied research), it is a process that can be conceptualized in terms of at least four characteristics.
First, research can assume many different forms. Second, research must be valid, both internally and externally (Box 4-1).
Internal validity is necessary but not sufficient for ensuring exter- nal validity. Third, research must be reliable. Reliability refers to the extent to which data collection, analysis, and interpreta- tion are consistent and to which the research can be replicated.
Fourth, research must be systematic. The elements of a systematic approach include the identification of the problem or problems, the gathering and critical review of relevant information, the col- lection of data in a highly orchestrated manner, an analysis of the data appropriate to the problem or problems faced, and the devel- opment of conclusions within the study’s framework.
Science is not a routine, cut-and-dried process. Rather, sci- entific knowledge emerges from an enterprise that is intensely human; as a consequence, it is subject to the full spectrum of human strengths and limitations. The scientific discovery and understanding that attend participation in research and its results can be professionally exhilarating and satisfying.
THE EIGHT CRITICAL STAGES IN THE RESEARCH PROCESS Research accords several personal freedoms to those who engage in it: the freedom to pursue those opportunities in which one is interested, the freedom to exchange ideas with other interested colleagues, and the freedom to be a deconstructionist—that is, one who challenges existing knowledge. Yet, despite these freedoms, research must be logical, must progress in an orderly manner, and ultimately must be grounded within the framework of the scien- tific method. If research is a way of searching for truths, uncover- ing solutions to problems, and generating principles that result in theories, we must come to understand the process of research.
The research process can be described in many different ways.
For purposes of simplicity, this process is defined as consisting of the following eight distinct stages:
1. Identification of the problem
2. Review of the relevant knowledge and literature 3. Formulation of the hypothesis or research question 4. Development of an approach for testing the hypothesis 5. Execution of the research plan
6. Analysis and interpretation of the data
7. Dissemination of the findings to interested colleagues 8. Evaluation of the research report
Stage 1: Identification of the Problem
The selection and formulation of the problem constitute an essen- tial first step in the research process. The researcher decides the general subject of the investigation, guided principally by personal experience and by inductions and deductions based on existing sources of knowledge. The researcher makes the general subject manageable by narrowing of the focus of the problem. The follow- ing criteria must be met at this phase of the research process:
• The problem area should be of sufficient importance to merit study.
• The problem must be one that is practical to investigate.
• The researcher should be knowledgeable and experienced in the area from which the problem has emerged.
• The researcher should be sincerely motivated and interested in studying the problem.
We constantly encounter problems and situations that can be studied. At clinical anesthesia conferences, one might hear remarks such as the following:
“It seems to me that a tiny dose of thiopental given just before propofol alleviates virtually any pain on injection.”
“Do you think there is less nausea and vomiting in outpatients who are deliberately overhydrated?”
“I find that the use of the waveform generated by my pulse oximeter gives me valuable information about depth of anesthesia.”
“I believe that the inspiratory pause mechanism on the Ohm- eda 7810 ventilator significantly improves arterial oxygen tension in my patients with chronic obstructive pulmonary disease.”
“I am convinced that sleepiness is a major cause of anesthesia accidents.”
A study could emerge from each of these situations, built on ideas, hunches, or curiosity. A problem that lends itself to research often materializes from personal observations and in the sharing of ideas and experiences among those who are familiar with the phenomenon in question.
Once identified, the problem should be stated in terms that clarify the subject and restrict the scope of the study. Defining the terms involved in the problem statement also is critical, as dem- onstrated in Box 4-2.
BOX 4-1
Research Scenario: Internal Versus External Validity Internal Validity
The extent to which results can be accurately interpreted and the degree to which the independent variable (that which is manipu- lated) is responsible for a change in the dependent variable (that which is measured).
For example, the patient’s blood pressure is measured. A com- bination of propofol, midazolam, isoflurane, and a new muscle relaxant is used for induction of anesthesia. A postinduction blood pressure is recorded, and the researcher concludes that the new muscle relaxant lowers blood pressure.
Questions
Has the researcher isolated the effect of the muscle relaxant from those of the other agents?
Are there plausible or competing alternative explanations?
Analysis
Internal validity is low because the results cannot be interpreted with any degree of certainty.
External Validity
The extent to which the results can be generalized; this issue relates to the question “To whom can the results be applied?”
For example, 35 obese men who are nonsurgical volunteers are anesthetized with a standard dose of a new induction drug.
The clinical half-life of the drug is determined with plasma drug sampling and brain wave activity monitoring. The researcher con- cludes that future patients receiving the standard dose of the new drug will experience a clinical half-life of 11 minutes.
Questions
Is it reasonable to assume that obese patients might respond differently than their nonobese counterparts?
Might women respond differently than men?
Could surgical manipulation or other drug therapy have an impact on the pharmacokinetics of the new drug?
Analysis
External validity is low because the results cannot be generalized to any other individuals except those similar to the subjects in the study.
UNIT II Scientific Foundations 38 t
The wording of the problem statement sets the stage for the type of study design used. Each step in the research process sub- sequently influences later steps, and this should be kept in mind at all times. A mistake made early inevitably creates difficulties at some later stage in the process. The novice researcher may be surprised to find that this first stage in the research process often consumes a large portion of the total time invested in the research effort. Yet the time is well spent, because research should not com- mence until a problem has been identified and formulated in a thoughtful and useful manner.
Common Mistakes
At this stage of the process, pitfalls can include an overly ready acceptance of the first research idea that comes to mind and selec- tion of a problem that is too broad or vague to allow effective study.
Stage 2: Review of the Relevant Knowledge and Literature
Once the problem has been identified, information is needed for putting the problem into proper context so that the research can proceed effectively. A well-conducted literature review provides the researcher with the following:
• An understanding of what has already been accomplished in the area of interest
• A theoretic framework within which the problem can be optimally stated, understood, and studied
• An appreciation for gaps in current understanding of the phenomenon
• Information for avoiding unanticipated difficulties
• Examples of potentially useful or poorly constructed research designs and procedures
• A background for interpreting the results of the proposed investigation
The knowledge that influences the problem originates from three general sources: personal files and experience, personal contacts with experts, and the library and Internet. Both manual indexes and computerized databases should provide the researcher with immediate and full access to the world’s published literature.
Additional literature searches may be required at different times throughout the research process.
Common Mistakes
At this stage in the research process, mistakes include hasty review of the literature, overly heavy reliance on secondary (book) rather than primary (journal) sources, lack of critical examination of
the methods by which conclusions were reached, and incorrect copying of references, for example, mistakes in noting the volume number or misspelling an author’s name, which makes it more dif- ficult to locate them again with ease.
Stage 3: Formulation of the Hypothesis or Research Question
In its most elemental form, a hypothesis is either a proposition of the solution to a problem or a stated relationship among variables.
It establishes and defines the independent variable (the variable that is to be manipulated or is presumed to influence the outcome) and the dependent variable (the outcome that is dependent on the independent variable). The hypothesis is declarative in nature and assumes one of the following three forms:
1. A directional hypothesis: Patients premedicated with mid- azolam have less anxiety on arrival in the operating room than do those who were not premedicated.
2. A nondirectional hypothesis: Patients premedicated with mid- azolam experience a difference in anxiety on arrival in the operating room when compared with those who were not premedicated.
3. A null hypothesis: Patients premedicated with midazolam experience no difference in anxiety on arrival in the operat- ing room compared with those who were not premedicated.
Research questions are generally reserved for investigations that are descriptive or exploratory in nature or for when the rela- tionships among the variables are unclear. A research question might be more appropriate than a hypothesis in a study that pro- poses to determine the beliefs of anesthesia providers who interact with patients under specific circumstances. For example, consider the following research question: What are the attitudes of CRNAs in the northeastern United States who care for patients with acquired immunodeficiency syndrome (AIDS)?
Common Mistakes
At this point in the process, mistakes include use of a vague or unmanageable hypothesis and development of a research question that cannot be answered reasonably.
Stage 4: Development of an Approach for Testing the Hypothesis
After the research idea has taken shape in the form of a formal hypothesis or research question, a plan of attack is developed. The research proposal represents the stage at which the ideas of the project crystallize into a substantive form. The proposal includes the following:
• A problem statement and clarification of the significance of the proposed study
• The hypothesis or research question
• A sufficient review of the literature for justification of the study
• A description of the research design
• A careful explanation of the sample to be studied • The type of statistical analysis to be applied
A research proposal is a useful and efficient way for the researcher to determine the completeness of the plan and is usu- ally required if the researcher is to obtain departmental or institu- tional approval or is applying for financial support.
Research Methods
The research method is the way the truth of a phenomenon is coaxed from the world in which it resides and is freed of the biases of the human condition. A variety of research methods are at our disposal, BOX 4-2
Research Scenario: Stating the Problem PoorI am unsure of the effectiveness of etomidate in patients.
Better
I am unsure at what dose etomidate induces unconsciousness in patients undergoing hysterectomy and what impact it has on heart rate, blood pressure, and vascular resistance.
Comments
• The problem should be focused.
• The terms should be clarified.
• The relationships should be understood.
• The problem should not be so narrow as to be trivial.
CHAPTER 4 Nurse Anesthesia Research t 39 and researchers are not inflexibly wedded to any particular approach.
Researchers do not follow a single scientific method but rather use a body of methods that are amenable to their fields of study.
Some of the methods available are highly recognizable, per- manent components of the researcher’s armamentarium, whereas others have evolved not only with respect to time but also in response to the specific needs of a particular problem or discipline.
The research method can be influenced by the way a researcher views a problem. For example, a researcher can test a hypothesis, search for a correlation, ask “why” or “how” questions, or probe a phenomenon on the basis of “what would happen if” suppositions.
The researcher can view the method on the basis of the funda- mental task that it will accomplish. For example, two broad cate- gories into which research efforts can be divided are basic research and applied research. Basic research adds to the existing body of knowledge and may not have immediate, practical use. Applied research is oriented toward solving an immediate, specific, and practical problem.
The research method can be characterized in terms of its tem- poral relationship to the problem. A retrospective study is the pro- cess of surveying the past; the thing in which we are interested has already occurred, and we are simply looking to see what did occur. In contrast, a prospective study looks forward to see what will happen in a given situation; here, the collection of data pro- ceeds forward in time.
It is important to understand several terms fundamental to the research process. As mentioned previously, the dependent variable is the object of the study, or the variable that is being measured.
The independent variable is the one that affects the dependent variable and is presumed to cause or influence it. Another way of looking at this relationship is that variables that are a consequence of or are dependent on antecedent variables are considered depen- dent variables.
Another set of variables consists of control variables, also known as organismic, background, or attribute variables. Control variables are not actively manipulated by the researcher, but because they might influence the relationships under study, they must be controlled, held constant, or randomized so that their effects are neutralized, canceled out, or at least considered by the researcher (Box 4-3).
The term blinding refers to the process of controlling for obvious and occult bias arising from subjects’ or researchers’ reactions to what is going on. In a single-blind design, the patients are unaware of which treatment or manipulation is actually being given to the subjects. In the double-blind design, neither the researcher nor the subject is aware of which treatment or manipulation the sub- ject is receiving. Whereas randomization attempts to equalize the groups at the start of the study, blinding equalizes the groups by controlling for psychological biases that might arise apart from any effect of the treatment. Many factors influence the decision to use a single-blind or a double-blind design. For example, in some situ- ations, it may not be feasible to disguise a particular treatment or intervention.
Operationalization is the process of making the characteristics inherent in a given variable, condition, or process familiar or clear to others. If researchers do not operationalize the terms, phrases, and manipulations in the study, the net effect could be an ambigu- ous study. For example, in a study examining the effects of epi- dural anesthesia in critically ill patients, it would be essential to operationalize the terms effects and critically ill patients. Similarly, in a study comparing the quality of inhalation induction with iso- flurane and sevoflurane in pediatric patients, it is essential that the researcher operationalize the terms inhalation induction and
quality. Operationalization of terms clearly designates performable and observable acts or procedures in such a way that they can be replicated immutably.
Classifying Research on the Basis of Methodology
Although different authors use a variety of classification schemes, the following example provides a simple way for the researcher to select and classify a design. This scheme attends to the study’s purpose and scope and to the nature of the problem at hand. Table 4-1 offers a simplified approach to classifying research design.
Quasi-experimental research differs from experimental research in that it is missing one or more of the key elements required for the experimental design. Either a control group or a randomiza- tion procedure may be absent from the design. For example, at an institution, outpatients may routinely receive ondansetron from a particular practitioner, whereas they routinely do not receive the drug from another practitioner. A prospective trial in which both practitioners use a standard anesthetic technique could be initi- ated. For example, isoflurane, an opioid, and cisatracurium could be administered; this would allow the two practitioners to use or not use ondansetron as they normally would. Outcome, measured in terms of the incidence of nausea and vomiting in the first 6 postoperative hours, is quantified, and the groups are compared.
Although randomization is not achieved, a study that may not otherwise have been possible because of the inflexibility of the cli- nicians involved is successfully accomplished. Quasi-experiments, by yielding to one or more of the rigid criteria of the experimental design, offer an attractive alternative in certain circumstances.
Qualitative Research: An Alternative Paradigm
Up to this point, the traditional approach to a problem has been characterized by deductive reasoning, objectivity, manipulation, and control. An alternative approach involves a group of methods characterized by inductive reasoning, subjectivity, exploration, and process orientation. These methods fall under the rubric of qualitative research techniques.
Qualitative techniques include philosophic inquiry, historiog- raphy, phenomenology, grounded theory, and ethnography. Gen- erally speaking, qualitative research refers to systematic modes of
BOX 4-3
Research Scenario: Understanding the Types of Variables
Study Group
A new intravenous drug that may be associated with fewer car- diovascular effects than thiopental during induction in pediatric patients is being studied. Fifty children ages 3 to 6 years undergo- ing intravenous inductions for hernia repair or eye muscle surgery are randomized to either the thiopental group or the new drug group. Blood pressure, heart rate, and rhythm are measured by a dedicated observer who is unaware of which drug the patients are receiving.
Analysis
The dependent variables are blood pressure, heart rate, and heart rhythm. The independent variable is the drug the child receives—
either the thiopental or the new drug. A number of control varia- bles are present, including sex, fluid status, time of day, underlying medical history, and concurrent drug therapy. With randomization, such control variables should be equated or neutralized for the two groups, but even randomization is not an absolute guarantee.