Chapter 5 Clinical skills for preparation of the patient and clinical environment
Great importance must be put on the maintenance of a safe and clean clinical environment for the patients. Within the diagnostic imaging department it should be recognised that all patients have the potential to carry and transmit organisms. It has been shown that nosocomial infections (those occurring in a hospital setting) can be reduced considerably with the introduction of basic hygiene procedures.1 In order to prevent the transfer of infections it is important to be aware of the specific organisms that can cause infection and the mode of transfer so that the cycle of replication can be disrupted.
A disease is a condition causing symptoms of an illness, which occurs when cells or molecules within the body stop functioning properly. For example, a disease can be caused through aging, the effects of chemicals, or arise from gene mutation/alteration.
There are four main groups of pathogenic organism which can cause diseases, some of which are harmless to the host when sited in the correct place; for example there are organisms living in the bowel which cause infection when they enter the urinary or respiratory tracts.
Bacteria are small unicellular organisms which are much smaller than a typical animal cell. There are many species of bacteria and they may be characterised in a number of ways, such as by shape (e.g. rod-like (bacilli) or spherical (cocci)). Within each species there are many different strains. Some bacteria are susceptible to treatment; however, there is an increase in the number of bacteria becoming resistant to drug treatments due to the overuse of antibiotics.
Viruses are not cellular and exist as genetic material (RNA or DNA) enclosed in a protein coat. Unlike bacteria, which replicate by a simple cell-division process, viruses require a cellular organism in which to reproduce. The genetic material invades the cell and hijacks the replication process. Antibiotics are ineffective against viruses; however, there are some antiviral agents (aciclovir) that prevent the virus from functioning normally, thus disrupting reproduction.
Fungi can be found in soil, air and water and are in fact primitive plants. Some fungi live in and on humans in balance without causing illness; these include Candida and Aspergillus species. Conditions caused by the presence of fungi are called mycoses. It is usually the unbalanced propagation of a fungus that causes the illness. Some antibiotics are fungi that are beneficial in the treatment of bacterial infections, one example being penicillin.
An infection occurs when other organisms, e.g. bacteria, viruses, fungi or protozoa, enter or come into contact with the body and multiply. The organisms can cause direct damage or prompt an immune response, which causes symptoms to manifest, e.g. fever.
Therefore, it is essential that the equipment, environment and healthcare professional are subject to varying levels of cleanliness dependent on the clinical requirement (Table 5.1). There arethree main levels of cleanliness that exist with regards to equipment and surfaces: clean, disinfected and sterilised.
|Cleaning agents||Purpose in department||Contraindications for use|
|Chlorhexidine gluconate solution 2.5%||For cleansing the skin prior to a procedure||Not for hard surfaces|
|Chlorhexidine gluconate 0.015%, cetrimide 0.15% (e.g. Savlon/Tisept/Sterets)||Not for hard surfaces or open wounds|
|Chlorhexidine gluconate solution 2.5% (e.g Hibiscrub)||None|
|Detergent, sanitiser, blue bleach powder (sodium hypochlorite)||For body fluids and spillages||Not for skin|
|Cleansing foam (e.g. Esemtan)||Antimicrobial deodorising foam||Not for hard surfaces, floors, etc.|
|Povidone iodine 7.5% (e.g. Videne antiseptic solution)||A rapid acting non-irritating aqueous iodine solution||For skin only. Not for hard surfaces, floors, etc.|
|Alcohol impregnated wipes||For hard surfaces and skin||Not for open wounds|
|Sodium chloride 0.9% solution||For skin and open wounds||None|
|‘Decon’||For neutralising radioactive spills||None|
Cleaning removes visible contamination (blood, faeces and the majority of microorganisms), normally using detergents. The process is designed to remove dirt and other materials from objects, surfaces or instruments. It can be done in water, with or without the inclusion of detergents. This is the first stage of removing contamination from the environment prior to disinfecting and sterilising.
Disinfecting reduces the number of microorganisms to a ‘non-harmful’ level by using chemical or heat treatment of items in contact with mucous membranes or bodily fluids. Spores are not usually destroyed. This process is halfway between cleaning and sterilising and a range of chemicals that inactivate most serious pathogens can be used. Immersing instruments in boiling water can ensure disinfection. In the case of floors, these will be mopped using chemical disinfectants, an example of which is chlorhexidine.
Specialised tape will seal the package. Non heat treated CSSD tape will have diagonal white lines: heat treated and therefore sterile tape will have black diagonal lines. A label will also indicate the date and cycle number of sterilisation (Fig. 5.2).