Castle EP, Wolter CE, Woods ME. Evaluation of the urologic patient: testing and imaging. In: Partin AW, Dmochowski RR, Kavoussi LR, Peters CA, eds. Campbell-Walsh-Wein Urology. 12th ed. Philadelphia, PA: Elsevier; 2021:chap 2. Germann CA, Holmes JA. Selected urologic disorders. In: Walls RM, Hockberger RS, Gausche-Hill M. Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier; 2018:chap 89. Nicolle LE, Drekonja D. Approach to the patient with urinary tract infection. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 268.
This article, the second in a four-part series, describes the procedure for collecting a catheter specimen of urine
Citation: Shepherd E (2017) Specimen collection 2: obtaining a catheter specimen of urine. Nursing Times [online]; 113, 8, 29-31. Author: Eileen Shepherd is clinical editor at Nursing Times. Obtaining a specimen involves collecting tissue or fluids for laboratory analysis or near-patient testing, and may be a first step in determining a diagnosis and treatment (Dougherty and Lister, 2015). Specimens must be collected at the right time, using the correct technique and equipment, and be delivered to the laboratory in a timely manner (Dougherty and Lister, 2015). Box 1 provides a reminder of the general principles of specimen collection, which were discussed in more detail in part 1 (Shepherd, 2017).
Box 1. Professional issues and good practice principles Nurses must:
The specimen must be:
The collection of any tissue/fluid carries a risk to staff from splash or inoculation injury, so standard precautions should be followed (Loveday, 2015). Indwelling urinary cathetersIndwelling urinary catheterisation involves the insertion of a tube into the bladder using aseptic technique (Dougherty and Lister, 2015). The procedure is carried out on patients for a variety of reasons, including to:
Catheters can also be used to manage incontinence and maintain skin integrity when all other conservative management strategies have been attempted and failed (Dougherty and Lister, 2015; Royal College of Nursing, 2012). Indwelling urinary catheterisation is associated with a number of complications, including:
As there is a risk of complications, catheters should be used only when no alternatives are appropriate. Catheters should also be removed as soon as clinically appropriate (Loveday et al, 2014). Catheter specimen of urineCatheter specimens of urine (CSU) are usually collected for microscopy, culture and sensitivity (MC&S) testing when an infection has been suspected. The urine is tested to identify the organisms causing the infection as well as their sensitivities to antibiotics. A CSU should only be collected when a patient has clinical signs of a CAUTI (Box 2). The decision should not be based solely on the sight or smell of urine in the drainage bag as these are not good indicators of infection in catheterised patients (Scottish Intercollegiate Guidelines Network, 2015).
Box 2. Clinical signs of CAUTI
Source: SIGN, 2015 Principles of specimen collectionIndwelling urinary catheters are usually attached to a drainage bag to create a closed drainage system. Breaking this closed system – for example by disconnecting the catheter from the drainage device or emptying the drainage bag, can increase the risk of CAUTI (Loveday et al, 2014). Some patients have a catheter valve in place instead of a drainage bag, which allows the bladder to fill and then requires the patient (or a health professional or carer) to release the valve and allow the bladder to empty. Using the catheter valve helps maintain bladder tone and can be the method of choice for some patients. For further information on catheter valves see Yates (2017b). A fresh sample of urine is required for a CSU and this must be obtained from the sampling port on the catheter bag or in the case of a catheter valve, directly from the valve. The sampling ports are designed to be accessed directly using a syringe and do not require a needle, therefore removing the risk of sharps injury (Dougherty and Lister, 2015). Samples should not be collected from the drainage bag tap as the urine specimen may be contaminated (Brekle, 2014) and inaccurate results may lead to inappropriate treatment. Ideally, samples should be collected before antibiotics are commenced as they may affect the result of the laboratory investigation. EquipmentThe following equipment is required:
The procedureCollecting from a sampling port
An aseptic non-touch technique (ANTT) must be used to obtain a CSU as this reduces the risk of cross infection (Rowley, 2011).
Collecting from a catheter valveFirst, follow steps 1-4 above and then:
Also in this seriesProfessional responsibilities Brekle B (2014) Specimen collection - microbiology and virology. Dougherty L, Lister S (2015) The Royal Marsden Hospital Manual of Clinical Nursing Procedures. Oxford: Wiley-Blackwell. Higgins D (2008) Specimen collection 1. obtaining a midstream specimen of urine. Nursing Times; 104: 5, 26-27. Loveday HP et al (2014) epic3: national evidence-based guidelines for preventing healthcare-2associated infections in NHS hospitals in England. Journal of Hospital Infection; 86: S1, S1–S70. Rowley S (2011) ANTT: A standard approach to aseptic technique. Nursing Times; 107: 36, 12-14. Scottish Intercollegiate Guidelines Network (2015) Management of Suspected Bacterial Urinary Tract Infection in Adults. Shepherd E (2017) Specimen collection 1: general principles and procedure for obtaining a midstream urine specimen. Nursing Times; 113; 7, 45-47. Yates A (2017a) Urinary catheters 5: teaching patients how to use a catheter valve. Nursing Times; 113: 5, 25-27. Yates A (2017b) Urinary catheters 1: male catheterisation. Nursing Times; 113: 1, 32-34. |