for the patient’s comfort. Artificial light should be strong enough to prevent eyestrain and diffuse enough to prevent glare. Whenever possible, provide a bed lamp for the patient. As discussed earlier under “Safety Aspect,” a dim light is valuable as a comfort and safety measure at night. This light should be situated so it will not shine in the patient’s eyes and yet provide sufficient light along the floor so that all obstructions can be seen. A night light may help orient elderly patients if they are confused as to their surroundings upon awakening. In conclusion, it is important that you understand the effects of the environment on patients. People are more sensitive to excessive stimuli in the environment when they are ill, and they often become irritable and unable to cooperate in their care because of these excesses. This is particularly apparent in critical care areas (e.g., in CCUs and ICUs) and isolation, terminal, and geriatric units. You must realize and respond to the vital importance of the environment in the total medical management plan of your patients. PATHOGENIC ORGANISM CONTROL LEARNING OBJECTIVE: Recall medical asepsis principles and recognize medical asepsis practices. All health care, regardless of who provides it or where it is provided, must be directed toward maintaining, promoting, and restoring health. Because of this goal, all persons seeking assistance in a healthcare facility must be protected from additional injury, disease, or infection. Adherence to good safety principles and practices protects a patient from personal injury. Additionally, attention to personal and environmental hygiene not only protects against further injury, but also constitutes the first step in controlling the presence, growth, and spread of pathogenic organisms. The discussion that follows addresses infection control, particularly in the context of medical and surgical aseptic practices. MEDICAL ASEPSIS Medical asepsis is the term used to describe those practices used to prevent the transfer of pathogenic organisms from person to person, place to place, or person to place. Medical aseptic practices are routinely used in direct patient care areas, as well as in other service areas in the healthcare environment, to interrupt a chain of events necessary for the continuation of an infectious process. The components of this chain of events consist of the elements defined below. Infectious Agent An infectious agent is an organism that is capable of producing an infection or infectious disease. Reservoir of Infectious Agents A reservoir of infectious agents is the carrier on which the infectious agent primarily depends for survival. The agent lives, multiplies, and reproduces so that it can be transferred to a susceptible host. Reservoirs of infectious agents could be man, animal, plants, or soil. Man himself is the most frequent reservoir of infectious agents pathogenic to man. PORTAL OF EXIT.—The portal of exit is the avenue by which the infectious agent leaves its reservoir. When the reservoir is man, these avenues include various body systems (such as respiratory, intestinal, and genitourinary tracts) and open lesions. MODE OF TRANSMISSION.—The mode of transmission is the mechanism by which the infectious agent is transmitted from its reservoir to a susceptible being (host). Air, water, food, dust, dirt, insects, inanimate objects, and other persons are examples of modes of transmission. PORTAL OF ENTRY.—The portal of entry is the avenue by which the infectious agent enters the susceptible host. In man, these portals correspond to the exit route avenues, including the respiratory and gastrointestinal tracts, through a break in the skin, or by direct infection of the mucous membrane. SUSCEPTIBLE HOST.—The susceptible host is man or another living organism that affords an infectious agent nourishment or protection to survive and multiply. Removal or control of any one component in the above chain of events will control the infectious process. Two Basic Medical Asepsis Practices The two basic medical asepsis practices that are absolutely essential in preventing and controlling the spread of infection and transmittable diseases are 2-29