IPC 4.1 Obtaining a clinical sample

Contents

  Introduction
 Definitions
 Legislative requirements
 Principles of specimen collection
 Hazard groups
 Storage of specimens
 Transportation of specimens  
 General recommendations
 Patient consent and education
 References
 Appendix 1
 Appendix 2
 Appendix 3
 Appendix 4
 Appendix 5
 Appendix 6
 Appendix 7
 Appendix 8
 Record of changes

 

1.0  Introduction

Organism

This guideline has been developed to ensure that the processes used within the organisation when obtaining clinical samples are robust, reflect best practice, and comply with legislations. 

The quality of clinical specimens and the method by which they are collected, stored, and transported can have a significant impact on ensuring an accurate diagnosis.

This guideline outlines the precautions required to prevent transmission of infection to staff and the wider community whilst obtaining, transporting, and handling specimens. These measures are required to ensure that high quality specimens are obtained for accurate diagnosis.

 

Definitions

A specimen: Defined as any bodily substance taken from a person for the purpose of analysis, such as blood or urine. All specimens will be regarded as potentially infectious, and all those involved in collecting, handling and transporting specimens are to be trained in and follow infection control precautions to prevent transmission of infection.

 

Legislative requirements

The collection, storage and transportation of specimens are governed by legislations relating to both transportation and health and safety at work.

The following legislation applies:

• Health and Safety at Work etc. Act 1974
• The Management of Health and Safety at Work Regulations 1999
• Control of Substances Hazardous to Health 2002 (COSHH)
• The Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations 2009

 

Principles of specimen collection

Success in the laboratory is dependent on the correct collection packaging, storage, and transportation of specimens. Failing to follow this may result in sample rejection and therefore delay in clinical diagnosis and treatment.

Clinicians should ensure that:

• Samples are only taken when clinically indicated, with the consent of the patient and documented clearly in the patients notes.
• Samples are of good quality. For guidance on taking specimens please refer to The Royal Marsden Manual of Clinical Nursing Procedures (The 'The Royal Marsden Manual of Clinical Nursing Procedures' page is on the Connect site), Diagnostic Tests.
• The specimen is taken at the correct time of day.
• The correct specimen container is used.
• Equipment used for the collection of specimens, are within expiry date, and are checked for exterior contamination and cleaned as necessary after filling.
• All sample lids are sealed tightly to avoid spills and contamination of the sample.
• The container and request form are both labelled with the patient’s name, date of birth, hospital or NHS number, and the date and time the sample was obtained and if a wound swab, the site swabbed. If multiple sites swabbed, each swab to be clearly labelled with the location of each site.
• The appropriate request form is fully completed with details of the patient’s relevant medical history, investigation required, and details of any antibiotic treatment received.
• The specimen container is placed in an approved specimen bag and correctly sealed.
• The specimen is stored correctly and transported to the laboratory promptly.
• The patient’s confidentiality is always maintained.

The clinician taking specimens will ensure that the following principles are followed:

• Effective hand hygiene is performed before and after collection of the specimen. NHS England » Chapter 1: Standard infection control precautions (SICPs)
• Appropriate protective clothing is worn when collecting the specimen, e.g. non-sterile gloves, apron and where splashing is possible or expected, goggles or visor. NHS England » Chapter 1: Standard infection control precautions (SICPs)
• Measures are taken to prevent any contamination of the sample. Refer to ANTT procedure, Nottinghamshire Healthcare Procedure .

Colleagues involved with the obtaining of clinical samples, need to be conversant with the process of managing spillages of body fluid. NHS England » Chapter 1: Standard infection control precautions (SICPs)

Microbiological results are an important factor in prescribing appropriate antibiotic therapy. To ensure that accurate microscopy, culture and sensitivity results are obtained steps should be taken to avoid contamination of the specimen from the patient, clinician or the environment.

Samples for microbiological investigation will be sent to the laboratory as soon as a patient is considered to have an infection, and ideally prior to the use of antibiotics. Specimens taken during antibiotic therapy may produce misleading results. If antibiotics have been commenced details must be provided on the sample request form.

All samples should be obtained using an aseptic non-touch technique (ANTT procedure) .

 

Hazard groups

Hazard Group 3 specimens from known or suspected high-risk infection, Table 1, should be clearly labelled as ‘danger of infection’. It is the clinician’s responsibility to ensure that tests that have been requested have the adequate clinical information documented on the request form and that ‘danger of infection’ is clearly labelled on the request forms and on the containers for all high-risk specimens.

Common Hazard Group 3 Biological Agent

Viral hepatitis	Typhoid Fever (Salmonella typhi/paratyphi)
HIV infection	Anthrax
Tuberculosis	Burkholderia pseudomallei
Creutzfeldt-Jacob disease	Shigella dystenteriae
Faecal samples from patients with E. coli O157 or Haemolytic uraemic syndrome	Faecal samples from patients with E. coli O157 or Haemolytic uraemic syndrome

Hazard group 4 specimens, such as viral haemorrhagic fevers samples should not be sent and advice must be sought from the IPC Team and Consultant Microbiologist in consultation with UKHSA.

 

Storage of specimens

For accurate results to be obtained, specimens ideally should be received and processed by the laboratory as soon as possible.

However, where this is not possible, specimens should be stored within a designated sample only refrigerator for a maximum of 24 hours, at 4-8°C. This will help prevent bacteria and contaminants from multiplying and giving misleading results. The fridge temperature should be checked daily, and records kept for 2 years.

Blood cultures must not be refrigerated, and they must be transported to the laboratory without delay.

 

Transportation of specimens

Under the Health and Safety at Work Act (1974), all staff have a responsibility to protect themselves and others e.g. the public, from any contamination from hazardous substances. All road transport of samples must be in accordance with current Carriage of Dangerous Goods by Road legislation.

Staff who carry/transport any clinical samples should ensure that samples are placed in a lidded, rigid, container that can be decontaminated.This is to prevent the risk of contamination in the event of spillage or leakage of the specimen. All transport containers should be decontaminated following each use.In the event of accidental spill, refer to NHS England » Chapter 1: Standard infection control precautions (SICPs). 

Staff must only transport specimens in their vehicles in appropriate United Nations approved containers (UN3373). The UN3373 symbol shall be clearly visible on all external packaging (Department for Transport, March 2020).

Examples of transport containers:

   

 

Out of hours transport

For Nottinghamshire based services The Nottingham Blood Bikers will provide transport to convey samples to the laboratories out of hours (see appendix 8). For other areas follow locally agreed processes.

 

General recommendations

To reduce risks, the number of persons handling specimens will be kept to a minimum. It is also essential that staff follow the correct procedures to maximise the potential for accurate laboratory results.

Everyone involved in collecting, handling and transporting specimens should be educated about standard infection prevention and control precautions and be familiar with relevant guidelines NHS England » Chapter 1: Standard infection control precautions (SICPs).

 

Patient consent and education

Clinical staff are to ensure that all tests are fully explained to patients so that they are able to give fully informed consent, and this to be documented in the patient’s notes. If a person has been assessed and deemed to lack capacity, then the decision to obtain a sample should be made only if this is in their best interest and if this has been made in agreement with the multidisciplinary team. The procedure should be fully explained to ensure that the patient is informed as to what to expect or what they need to do e.g. when providing mid-stream urine sample, and this will then be documented within the Multi-Disciplinary Notes in line with the 01.06 Consent to Examination or Treatment and the 05.11 Deprivation Of Liberty Safeguards (Mental Capacity Act 2005).

There are to be clear local systems for informing patients of test results. At the time of the test, the patient will be advised of how long they will have to wait for the test result and the method by which they will be informed of it e.g. during their in-patient stay, a follow up appointment or by post. Isolation may be required while waiting for the results, dependent on the clinical manifestation. 

When results are returned to a clinical area, there should be robust systems in place to ensure that results are:

Documented within the multidisciplinary notes and actioned appropriately.

The clinician that has requested or undertaken the test, or procedure, is responsible for accessing the results in a timely manner. 

• Appendix 1: Common Clinical Samples
• Appendix 2: Collection of Stool Specimen for microbiology/virology investigations
• Appendix 3: Collection of Urine Samples for microbiology 
• Appendix 4: Appendix 4 Sputum Collection 
• Appendix 5: Wound Swabs
• Appendix 6: Taking a rectal swab
• Appendix 7: Taking a throat swab
• Appendix 8: Blood Bikes Flyer

 

Appendix 4

Sputum Collection 

Sputum samples will ideally be collected in the morning before eating, drinking and after brushing the teeth and rinsing well with water (do not use mouth wash). Brushing the teeth will reduce the risk of the sample being contaminated with debris or microbes present in the mouth.

If the sputum is thick and difficult to clear, administering nebuliser therapy may help to loosen the secretions. Alternatively, a physiotherapist may be able to assist. 

• For every sample appropriate PPE must be worn following a risk assessment. 
• Explain the procedure to patient and gain consent to proceed.
• Position the patient comfortably in an upright position supporting where necessary.
• Wash hands and assemble equipment on a cleaned surface.
• Apply PPE

Encourage the patient to take three deep breaths in through the nose and exhale through pursed lips (bring the lips tightly together so that they form a rounded hole shape), then force a cough.

• Encourage the patient to spit the sputum into the sample pot.
• Check the sample quality. Samples that are predominantly saliva will be rejected. 
• Remove PPE, place all waste in the correct waste stream. 
• Wash hands. 
• Ensure the specimen is correctly labelled and sent to the lab promptly. Samples should be refrigerated at 4-8°C before transit to the lab. If a sample fridge is not available, time the collection of the sample to coincide with sample transport collections.
• Record the procedure in the patients notes. 

 

Appendix 5

Wound Swabs

Taking a wound swab is only recommended when clinical signs of infection are identified, and the information gained will affect treatment, or for screening purposes. Clinical signs of infection are:

• The wound is red, hot or painful beyond what is expected for normal healing.
• And/or the wound is discharging pus/exudate.

As with all investigations any wound swab isolates should be reviewed alongside other clinical information and symptoms, and treatment will not be based on swab results alone.

If Fungal infection suspected ensure this is documented on the sample as won’t be routinely screened for.

If possible, it is best practice to take a swab before antibiotics are started.

Swab sampling: wound - Royal Marsden Manual (rmmonline.co.uk)

• Gain informed consent from the patient.
• Gather all the equipment needed for the task.
• Maintain patient dignity and close any privacy curtains and turn off any fans in the room.
• Wash hands.
• Apply appropriate PPE.
• Remove the dressing.
• Cleanse the wound to remove loose debris as this is likely to contain high levels of colonising bacteria which are not representative of the infective organism.
• If the wound is dry, moisturising the swab with sterile normal saline taking care not to touch the swab. This will help any organisms stick to it.
• Rotate the swab tip over a 1cm2 area of viable tissue, at or near the centre of the wound, for 5 seconds, applying enough pressure to express tissue fluid from the wound bed. Place the swab directly into the tube.
• Before continuing to dress the wound replace any PPE ensuring hands are decontaminated before replacement.
• Immediately after dressing the wound discard any waste into the appropriate waste stream, remove PPE and decontaminate your hands.
• Carefully label and send to the laboratory as quickly as possible.
• Delayed swabs can be stored in a dedicated samples fridge for 24 hours 4-8°C. 

It is important that the specimen is supported with sound clinical information recorded on the microbiology request form. Details relating to the service user’s symptoms of infection, what type of wound it is and treatment history will assist the microbiologist in making an accurate diagnosis and appropriate recommendations for management.

Sensitivities for antibiotic treatment are not always returned with culture results because many isolates reflect bacterial colonisation, rather than infection. It may be necessary to obtain advice from the microbiologist to discuss the results and treatment of the case.

 

Appendix 6

Taking a rectal swab

Requested by prescribing clinician, ensuring privacy and dignity, chaperone and consent are documented and considered.

• For every swab appropriate PPE must be worn following a risk assessment. 
• Explain the procedure to patient and gain consent to proceed.
• Position the patient comfortably on their side with knees bent.
• Wash hands and assemble equipment on a cleaned surface.
• Apply PPE
• Insert the swab 2-3 cm into the rectum, gently rotate the swab 5-10 times and then remove. Ensure faecal material is present on the swab.
• Place the swab into the container and firmly apply the lid.
• Remove PPE, place all waste in the correct waste stream. 
• Wash hands with soap and water
• Ensure the specimen is correctly labelled and sent to the lab promptly. Samples should be refrigerated at 4-8°C before transit to the lab.
• Record the procedure in the patients notes. 

     

 

Appendix 7

Taking a throat swab

Taking a throat swab is recommended to obtain samples of the mucous membrane. It may be used to identify a microorganism in a suspected infection or part of a screening programme to identify patients who may be carrying pathogens, such as Group A Strep, without displaying signs and symptoms. 

Pathogens in the throat can be viral or bacterial so it essential the appropriate swab is selected for the suspected infection.

Examples of a Viral Swabs

     

An aseptic non touch technique (ANTT) is used to collect the sample to ensure that it is not contaminated from surrounding tissues or environment.

• For every swab appropriate PPE must be worn following a risk assessment. 
• A single use tongue depressor can be used to enable visualisation of the throat. 
• Explain the procedure to the patient and gain consent to proceed.
• Wash hands and assemble equipment on a cleaned surface (include suitable container in case patient gags).
• Apply PPE
• The patient needs to tilt the head back, sitting upright towards a light source. 
• Patient should be asked to open mouth and stick out the tongue. 
• The swab should be taken from the throat, over the area of inflammation, over tonsils and posterior pharynx, taking care not to contaminate it with other mucosal areas. 
• For Influenza, RSV and COVID-19 if you are unable to swab the throat for any reason swab both nostrils using the same swab as below*.
• The patient may gag during the procedure. Try to relax the patient and ask them to say “ah”.
• *If you are taking a sample for Influenza, RSV or COVID-19 now insert the same swab 2-3 cm into one nostril or until you feel some resistance. Rotate the swab firmly around the nostril 10 times.If there are any piercings present swab the nostril which is piercing free. If both nostrils have piercings remove the piercing from one side before swabbing.
• Remove PPE, place all waste in the correct waste stream. 
• Wash hands 
• Ensure the specimen is correctly labelled and sent to the lab promptly. Samples should be refrigerated at 4-8°C before transit to the lab.
• Record the procedure in the patients notes.

 

Appendix 8