Using scientific principles when there is no research

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  • MAY 1999, VOL 69, NO 5 R E S E A R C H C O R N E R

    Using scientific principles when there is no research

    his column is the first in a series in which we address T approaches to solving clinical

    problems when there is no research or the research evidence is inconclusive. This column addresses the use of scientific principles or rationales as an approach to help guide practice. Keep in mind that not all scientif- ic principles or rationales are proven facts and that scientific knowledge is expanding at an exponential rate. What we believed to be true facts even a few decades ago has been super- seded by new knowledge. Thus, it is imperative that we are continu- ously aware of new information and research so that we can be effective decision makers.


    Asepsis serves as a good example of how scientific princi- ples guide practice. By exploring some of the historical perspec- tives related to asepsis, one can more fully understand the practi- calities as well as the inconsisten- cies of using scientific principles to guide practice. Medical and surgical asepsis are so ingrained in our practice that we rarely question their use. Fortunately, the early pioneers in health care questioned the prevailing wisdom of their time (eg, not washing hands, not using sterile supplies and equipment), and today we practice in environments that minimize the risks of nosocomial and iatrogenic infections.

    Imagine practicing in the era of Florence Nightingale, when very little was known or under- stood about the transmission of infection. Acting mostly on instinct, Nightingale recommend- ed pure air and water, cleanliness and daylight, and effective drainage as ways of promoting health and preventing disease. Her wisdom was further support- ed by the work of Ignaz Semmelweis, who recommended hand washing, and Louis Pasteur, who taught germ theory to physi- cians. These novel ideas generat- ed a great deal of controversy when many people doubted, questioned, or dismissed these proposed theories and scientific rationales.

    Great strides in surgical prac- tice were made when Joseph Lister used germ theory as the basis and rationale for sanitizing the OR. Lister, who many consid- er the father of modem surgery, searched for a chemical that would kill bacteria. It was through his efforts that carbolic acid was introduced as a disinfectant in the OR, in the air as a disinfectant spray, on surgical dressings, and on the hands of surgeons and nurses. Carbolic acid use decreased patient mortality rates that occurred as the result of infection, but it also had the unfortunate side effect of killing healthy tissue in both patients and health care providers. In spite of nearly two decades of improved infection rates, Listers theories and recommendations were not

    widely accepted until 1879.

    gical practice would be today if the work of nineteenth century scientists had been accepted as the final truth. We would still have unacceptable rates of surgery- acquired infections in both patients and health care providers. For example, carbolic acid is a harsh, corrosive chemical. It severely damaged the skin of sur- geons and nurses. In Baltimore in 1889, William Stewart Halstead, MD, and a surgical nurse working at Johns Hopkins Hospital began wearing rubber gloves to protect their skin. When others saw how effective the gloves were in pre- venting damage to the skin, gloves were quickly and widely adopted at Johns Hopkins. At the same time, the infection rate of patients fell dramatically; health care professionals then drew the connection between glove use and decreased infection rates. If Dr Halstead had stood by his premise that the only rationale for wearing gloves was to protect the hands, it might have been decades before the relationship between microor- ganisms and surgical infections was understood. Although there is limited documented research from the nineteenth century to support glove use, the basic understanding of the principles of disease pre- vention has withstood the test of time and is critical to surgical asepsis today.

    understood the relationship between bacteria and infection,

    Think for a minute where sur-

    As surgeons and nurses better


  • MAY 1999. VOL 69, NO 5

    surgical asepsis became the stan- dard. By 1910, surgery routinely was performed using masks and sterile equipment, supplies, gowns, and gloves. This knowl- edge explosion related to germ theory and asepsis continues to provide the basic foundation for surgical practices today. Much of this understanding has been derived through trial-and-error processes as well as the identifica- tion of basic scientific principles. In spite of the fact that little research exists on surgical asepsis, few would suggest abandoning these practices or proposing ran- domized controlled studies in which patients would be subjected to a lower standard of surgical preventive care.

    DEFINING SCIENTIFIC PRINCIPLES At this point, you may be ask-

    ing, What is a scientific princi- ple? Most experts define a scien- tific principle as a basic law or fact from which other information or ideas are derived. For example, an established scientific principle is that droplet nuclei suspended on dust can result in the transmis- sion of certain airborne infections. From that fact, we build the rationale that wearing masks in the surgical setting may reduce the spread of airborne infections. A rationale is simply a statement that is developed from a scientific fact to explain additional details.

    The basic principles related to the transmission of bacteria pro- vide the basis and rationale for surgical asepsis. Today, we believe that bacteria are transmit- ted by contact transmission, vehi- cle transmission, airborne trans- mission, and vectors. Principles

    N O T E

    related to breaking the chain of infection are implemented in ORs to prevent infections. In this instance, antiseptics, disinfectants, and sterilization techniques are used. Knowledge and understand- ing in this arena does not stand still-new information and new infective agents, as well as new types of equipment, lead to changes in clinical practice.

    A major change in this century has been related to developing an understanding of how infections are transmitted by blood and body fluids. In the late 1950s, many experts considered human blood to be a sterile fluid. Little was known about how blood might be responsible for the transmission of infections (eg, hepatitis, HIV). Before the implementation of uni- versal precautions, gloves were rarely used when health care workers were in contact with a patients blood or body fluids. In fact, one of the first transmissions of HIV that occurred in a health care worker involved a nurse who held pressure to a bleeding wound using bandages and her ungloved hands.

    Today in surgical practice, many are questioning clinical prac- tices that some claim to be sacred cows. Practices such as wearing home-laundered scrubs and using surgical masks are two such issues. For example, naysayers claim there is a lack of scientific research to support the use and efficacy of masks. Trying to conduct research that definitively decides these issues would be labor intensive and prohibitively expensive (see the December 1998 Research Comer for more discussion of research costs). In situations such

    as this, we must rely on scientific principles and existing knowledge to guide practice. Remember that just one serious airborne infection is clinically significant to the indi- vidual, whether it be a patient or staff member, who is infected by someone who is not wearing a mask. Statistical significance is surely not important to that per- son-the fact that the individual became ill or disabled is the most significant outcome.

    These examples illustrate and reinforce the fact that there are many unclear and untested prac- tices in health care. Each of us has the responsibility of knowing the scientific principles that guide our practice. Until research evidence suggests another understanding or truth, we must adhere to practices that are tried and true. That is not to say that nothing should change, but change should occur based on new information, facts, or evi- dence generated from research. We should all be grateful that Semmelweis discerned that wash- ing his hands and changing his gown between patients resulted in an eradication of puerperal fever. We need to question each practice, regardless of the prevailing wis- dom: however, when research can- not answer the question, we must identify and use scientific princi- ples-not the prevailing whim.





    Prevention. UDdate: Human immunodeficiencv virus I 1

    1. Nurse infected with HIV virus urges others to take infections in health-care workers exposed to blood of infected patients, Morbidity and Mortality Weekly Report 36 (May 22, 1987) 285-289.

    care [news], American Journal ($Nursing 90 (December 1990) 86: Centers for Disease Control and




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