LEARN
STEP #2 Make the connections to key topics.
UNIT THREE
216
Nursing Basics
Another step in identifying which coccus, bacillus, or spi- rillum is under the microscope involves using a dark purple stain called a Gram stain. The slide containing the microor- ganism is ooded with Gram stain and then rinsed with alco- hol. It is counterstained with safranin and then rinsed with water. When the slide is viewed under the microscope again, the bacteria will have taken up the stain. Those that appear either purple or blue are known as gram-positive organisms. Those that appear pink or red are identi ed as gram-negative organisms. The amount and type of stain the bacterium retains is dependent on the composition of its cell wall. Different medications are most effective for different types of organ- isms and are prescribed based on their Gram stain response. Rickettsia are a type of bacteria, but they are different from most because they can only reproduce inside the cells of the host, similar to the way viruses must reproduce. Rick- ettsia are often spread through the bites of insects, such as ticks and mites, which are called vectors. The insects are carriers of the microorganisms, and when they bite a human, the human becomes ill as a result of infection from the rick- ettsia bacteria. Antibiotics are prescribed to treat infections caused by bacteria. There are many types of antibiotics, and each acts in a slightly different way to kill bacteria. (For more infor- mation about antibiotics and their actions, see Chapter 35.) It is important to note that antibiotics are effective against most bacteria. Multiple-drug-resistant organisms, also called MDROs, are bacteria that have mutated in such a way that they are resistant to many of the antibiotics normally used to treat infections. Examples of MDROs are MRSA, vancomycin-resistant enterococcus (VRE), and Clostrid- ioides dif cile, also called C. diff. Infections with these organisms are particularly dif cult to resolve because of their antibiotic resistance. Only a few antibiotics are effective against each of them. is examined under a microscope, the medical laboratory technologist identifies the bacterium by its shape (Fig. 14.1). Cocci ( singular coccus) are sphere-shaped bacteria. Sometimes they may be seen in clusters and are similar to grapes in appearance. These are known as staphylococci. They may also appear in chains, like a bead necklace, and are then referred to as streptococci. Or they may appear in pairs, like two balls side by side, which are described as diplococci. Bacilli (singular bacillus) are rod-shaped bacteria. They have a log-like appearance and may vary in length. Spirilla (singular spirillum) are long cells that spiral or coil, similar to a curl of long hair.
When you work in a hospital as a student or as a staff nurse, you are surrounded by some virulent germs. This can be very alarming if you do not understand the causes of infection or do not know how to protect yourself and your patients from disease-causing microorganisms. In this chapter, you will learn how to protect yourself and how to prevent the spread of disease-causing germs to other patients or your family. CAUSES OF INFECTION Infections are caused by a variety of microorganisms. These are minuscule living bodies that cannot be seen with- out a microscope. Microorganisms that cause infection in humans are referred to as pathogens. They reproduce rap- idly and can spread from one area of a person’s body to another. Not all microorganisms are pathogenic, however. Many microorganisms live in and on our bodies, performing needed functions to protect us from harmful pathogens and helping us break down and digest food. These microorgan- isms are referred to as normal ora. Types of Pathogens Pathogenic microorganisms are classi ed as bacteria, viruses, protozoa, fungi, or helminths. Bacteria Bacteria are one-celled microorganisms found virtually everywhere, including in the human body. It is only when they invade an area outside their normal location that prob- lems result. For example, several bacteria live in the intes- tines to help the body digest food and absorb vitamins. They belong there. However, if those particular bacteria are intro- duced into the urethra and migrate to the bladder, they could cause a urinary tract infection. The most common bacteria are Staphylococcus aureus. CRITICAL THINKING CONNECTION—cont’d because you are worried that you might catch the infection or take the microorganism home to your children. Critical Thinking Questions 1. What is MRSA? 2. What precautions would you use before entering the patient’s room? 3. What treatment will you expect to be ordered for this patient? Laboratory and Diagnostic Connection Identifying Bacteria in the Laboratory Bacteria are named and classified by their shape. A specimen of drainage, sputum, stool, urine, or blood is obtained and sent to the laboratory. When the specimen
CHAPTER 14 Medical Asepsis and Infection Control
KEY TERMS
LEARNING OUTCOMES
1. Define various terms related to medical asepsis and infection control. 2. Describe five types of pathogens. 3. Identify selected common illnesses caused by microbes. 4. Illustrate the chain of infection. 5. Differentiate types of infections. 6. Compare primary, secondary, and tertiary defenses against infection. 7. Explain factors that decrease the body’s defenses. 8. Differentiate between the use of standard precautions and transmission-based precautions. 9. Compare the purposes and types of transmission-based precautions. 10. Compare medical and surgical asepsis. 11. Explain nursing responsibilities for cleaning the environment and equipment. 12. Describe when and how to use hand hygiene. 13. Detail the use of standard precautions. 14. Explain ways to meet the emotional needs of patients who are isolated because of communicable disease. 15. Discuss information in the Connection features in the chapter. 16. Identify safety issues related to medical asepsis and infection control. 17. Answer questions about performing the skills in this chapter.
Chain of infection (CHAYN uv in-FEK-shun) Direct contact (dih-REKT KON-takt) Disinfectant (DISS-in-FEK-tent) Health-care–associated infection (HELLTH- KARE-a-SOH-see-ayt-ed in-FEK-shun) Indirect contact (IN-dih-rekt KON-takt) Localized infection (LOH-kuh-LYEZD in-FEK- shun) Medical asepsis (MED-ih-kuhl ay-SEP-siss) Microorganism (MY-kroh-OR-gan-izm) Normal flora (NOR-mal FLOR-ah) Pathogen (PATH-oh-jen) Primary infection (PRY-mare-ee in-FEK-shun) Secondary infection (SEK-un-DARE-ee in-FEK- shun) Standard precautions (STAN-derd prih-KAW- shuns) Systemic infection (sis-TEM-ik in-FEK-shun) Transmission-based precautions (trans-MIH- shun BAYST prih-KAW-shuns) Vector (VEK-tur)
20
Infection Prevention & Control
20
Infection Prevention & Control
CHAPTER CONCEPTS
Infection Safety Immunity Caring Evidence-Based Practice
SKILLS
Infection Prevention & Control
20
14.1 Performing Hand Hygiene 14.2 Donning Personal Protective Equipment 14.3 Removing Personal Protective Equipment
CRITICAL THINKING CONNECTION Clinical Assignment
You are assigned to care for a 38-year-old male patient who has an infection caused by methicillin-resistant Staphylococcus aureus (MRSA). You know this is a highly contagious infection that is resis- tant to many antibiotics. It frightens you to care for this patient
Continued
• WORD • BUILDING • microorganism: micro – small + organism – life form pathogen: patho – disease + gen – producer
215
4455_Ch14_215-236.indd 215
1/19/22 4:54 PM
4455_Ch14_215-236.indd 216
1/19/22 4:54 PM
Assignments in Davis Advantage correspond to key topics in your book. Begin by reading from your printed text or click the eBook button to be taken to the FREE, integrated eBook.
Pre-Assessment for Medical Asepsis and Infection Control
You’ll receive immediate feedback that identifies your strengths and weaknesses using a thumbs up, thumbs down approach. Thumbs up indicates competency, while thumbs down signals an area of weakness that requires further study.
Question 2 of 6 A patient is asking the nurse about multiple-drug-resistant microorganisms. Which microorganisms are considered multiple-drug-resistant? Select all that apply. MRSA VRE Trichomonas vaginalis Rickettsia rickettsii Clostridioides difficile
Pre-Assessment for Medical Asepsis and Infection Control
Following your reading, take the Pre-Assessment quiz to evaluate your understanding of the content. Questions feature single answer, multiple-choice, and select-all-that-apply formats.
Online content subject to change upon publication.
Powered by FlippingBook