The Royal Marsden Hospital Manual of Clinical Nursing Procedures - Lisa Dougherty [435]
Antimicrobials, particularly broad-spectrum antibiotics, alter the normal gut flora, allowing C. diff to proliferate and become pathogenic in the absence of other organisms (Carney et al. 2002). This leads to the production of toxins that irritate and cause mucosal damage of the intestinal tract.
The diagnosis of C. diff is through faecal sampling for culture and toxin analysis on patients who develop diarrhoea or who are admitted to healthcare institutions with unexplained diarrhoea.
Evidence-based approaches
Rationale
Timely and accurate identification of patients with infective diarrhoea is crucial in individual management of colonization and within the context of effective infection control management. Obtaining the specimen provides important diagnostic information that can be used to decide how to manage the patient’s condition and the mode of treatment (Kyle 2007). Prompt diagnosis can influence aspects of care such as isolation and cohort nursing of infected patients, infection control procedures, environmental decontamination and antibiotic prescribing (DH 2007c).
Indications
Collection of a faecal specimen is indicated:
to identify an infective agent in the presence of chronic, persistent or extended periods of diarrhoea
if patients are systemically unwell with symptoms of diarrhoea, nausea and vomiting, pain, abdominal cramps, weight loss and/or fever
to investigate diarrhoea occurring after foreign travel
to identify parasites, such as tapeworms (Pellatt 2007b)
to identify occult (hidden) blood if rectal bleeding is suspected (Pellatt 2007b)
in the presence of diarrhoea associated with prolonged antibiotic administration
for symptomatic contacts of individuals with certain organisms (e.g. E. coli 0157) where an infection can have serious clinical sequelae (HPA 2008d).
Contraindications
As routine testing.
In the absence of diarrhoea in suspected infective colonization.
Principles of care
A sample should be obtained as soon as possible after the onset of symptoms, ideally within the first 48 hours of illness, as the chance of successfully identifying a pathogen diminishes once the acute stage of the illness passes (Weston 2008). The specimen should be obtained using a clean technique in order to avoid inadvertent contamination of the specimen (HPA 2008d).
Preprocedural considerations
Assessment and recording tools
Collecting a faecal sample should be considered in conjunction with a comprehensive nursing assessment. This includes the observation of faeces for colour, presence of blood, consistency and odour (Pellatt 2007b). The most widely used assessment tool is the Bristol Stool Chart (Lewis and Heaton 1997), which categorizes faeces into seven classifications (types) based upon the appearance and consistency. Samples sent to the microbiology laboratory for analysis of suspected C. difficile should be classified as Type 6/7 on the Bristol Stool Chart (HPA 2008d).
In addition to other associated symptomology such as vomiting, fever, myalgia or abdominal pain, an accurate history should also include the onset, frequency and duration of diarrhoea, and other information such as history of foreign travel or potential food poisoning.
Procedure guideline 11.17 Faecal sampling
Essential quipment
A clinically clean bedpan or disposable receiver
Sterile specimen container (with integrated spoon)
Gloves
Apron
Appropriate documentation/forms
Preprocedure
Action Rationale
1 Discuss need and indication for procedure with patient. To ensure the patient understands the procedure and gives valid consent (NMC 2008b, C).
2 Wash hands with bactericidal soap and water, or decontaminate physically clean hands with alcohol-based handrub. Don apron and gloves. To reduce the risk of cross-infection and specimen contamination (DH 2007a, C).
Procedure
3 Ask patient to defaecate