The Royal Marsden Hospital Manual of Clinical Nursing Procedures - Lisa Dougherty [406]
Hospital number.
Investigation required so as to avoid indiscriminate specimen analysis which wastes time and money.
Date and time of specimen collection.
Type and site of specimen. This should specify the actual anatomical site, such as ‘abdominal wound’, as this allows the laboratory to differentiate and assess the significance of results based upon the flora normally associated with that site (Miller 1998).
Diagnosis and relevant clinical information which can help in the interpretation of a sample (Higgins 2007).
Relevant signs and symptoms.
Relevant history, for example recent foreign travel.
Present or recent antimicrobial therapy.
Whether the patient is immunocompromised as these patients are highly susceptible to opportunistic infections and non-pathogenic organisms (Weston 2008).
Consultant’s name.
Name and contact details of the doctor requesting the investigation, as it may be necessary to telephone the result before the report is dispatched.
If a high-risk specimen, it should be labelled with a ‘danger of infection’ label (HSE 2003).
Communication
For certain specimens that have specific collection techniques or require prompt processing, communication with the laboratory before the sample collection and/or providing information that a sample is being sent to the laboratory can improve efficiency of processing and accuracy of results.
Collecting specimens
The production of high-quality, accurate results which are clinically useful is very much dependent upon the quality of the specimen collection (Higgins 2007). The greater the quantity of material sent for laboratory examination, the greater the chance of isolating a causative organism.
Specimens should be taken as soon as possible after the manifestation of clinical signs and symptoms. The timing of specimen collection is especially important during the acute phase of viral infections. Many viral illnesses have a prodromal phase where multiplication and shedding of the virus are usually at their peak and when the patient is most infective (Mims 2004). This is often before the onset of clinical illness and has often ceased by about day 5 from the onset of symptoms. At this stage, the patient’s immune response against the virus has already been mounted and may therefore affect organism isolation (Winter 2005).
Specimens are readily contaminated by poor technique and analysis of such specimens could lead to adverse outcomes such as misdiagnosis, misleading results, extended length of stay or inappropriate therapy (Miller 1998). Therefore, a clean technique must be used to avoid inadvertent contamination of the site of the sample or the specimen itself. Specimens should also be collected in sterile containers with close-fitting lids or with sterile swabs.
Postprocedural considerations
Labelling specimens
Prompt microbiological analysis is only possible if specimens and their accompanying request forms are sent with specific, accurate and complete patient information. Incorrectly or unlabelled specimens will be discarded (HSE 2003).
Samples should include the following information.
Patient’s name, date of birth, ward and/or department.
Hospital number.
Date and time of specimen collection.
Type and site of specimen. This should specify the actual anatomical site such as ‘abdominal wound’ as this allows the laboratory to differentiate and assess the significance of results based upon the flora normally associated with that site (Miller 1998).
If a high-risk specimen, it should be labelled with a ‘danger of infection’ label (HSE 2003).
Transporting specimens
An awareness of the type of organism being investigated and their growth requirements gives the healthcare professional an insight into the correct collection, storage and transportation methods (Table 11.1). Most micro-organisms are also extremely susceptible to environmental fluctuations such as pH, temperature, ultraviolet rays and oxidizing agents (Gould and Brooker 2008). Incorrect or prolonged storage or transportation may result in the organism not surviving before cultures