An initial consultation was released on this topic in 2017. There was only a small amount of feedback but what we received was generally positive. Given the time period that has passed since the last consultation it was decided that a further consultation should be held, describing in more detail the rationale. This proposal would make clinical details compulsory on all microbiology samples, however we have illustrated how it might affect some of the main sample types; e.g. wound swabs, urines, sputa. (See appendices A, B & C).
Elsewhere in New Zealand, clinical details are pre-requisite for microbiology requests in Dunedin and its catchment areas, as well as Wellington Hospital.
Our objective is to receive brief but pertinent clinical details on all diagnostic microbiology samples, which we believe will optimise the quality of the results that we release. We also believe that such an approach will have positive effects on antimicrobial stewardship.
The rationale for clinical details can be split into three areas of the testing process; pre-analytical, analytical and post-analytical. There will however be overlap between the three areas:
Pre-analytical:- Clinical details allow us to decide if the test is appropriate for a given clinical situation and whether extra or alternative testing may be indicated.
Analytical:- This area is particularly important for samples which are processed for bacterial culture. Clinical details can (and often do) affect any of the following steps in the bacteriology culture process:
Post-analytical: This allows us to decide whether the culture findings are consistent with the clinical details, which antibiotics should be reported, if any, which interpretative or management comments should be added.
It is anticipated that this policy would be extended to apply to all “non-critical” microbiology samples. Such a policy would not be appropriate for “difficult to obtain”, or “critical” specimens, e.g. theatre samples (including minor surgery), blood cultures, cerebrospinal fluid (CSF) and other sterile site fluids. Ironically, these are samples for which clinical details are of the greatest importance and are still strongly recommended.
For microbiology samples submitted to Pathlab, clinical details are already pre-requisite for certain sample types; enteric samples, vaginal swabs, ear swabs, and infectious serology.
It is accepted that the appropriateness and extent of clinical details is a very subjective area. Therefore such a policy would be implemented with a strong degree of leniency as to what is acceptable with regards to clinical details. A brief summary of the clinical reason for testing is paramount. Current antibiotics, allergies, and immunocompromising conditions should be included, along with any other key information that would be useful to the laboratory dependent on the clinical situation. Examples might be travel or occupational history, pets, history of trauma, history of multi drug resistant organisms (MDROs), co-morbid conditions, etc.
Yes, it is envisaged that such a policy would apply to microbiology samples from both hospital and community settings, and throughout all the regions that Pathlab covers (Waikato community, Bay of Plenty hospitals and community, Lakes hospitals and community).
Pre-requisite clinical details for all microbiology samples would apply for request forms received in both the manual and electronic formats.
Electronic requesting has the future potential to facilitate a pre-requisite clinical details policy, with the gatekeeping in this area being performed during the requesting process and before the sample reaches the laboratory.
This consultation document will be circulated to all laboratory requestors and the Laboratory/Clinical governance committees for the BOP, Waikato and Lakes DHBs.
It is believed that this proposed move is an important step in optimising the provision of high-quality microbiology results from the laboratory. It would also seek to optimise the links and communication between clinicians and the laboratory, an area we are constantly working to improve.
All your feedback is welcome and strongly encouraged, positive or negative. Please direct such feedback by 14th June 2019 to ClinicalMicrobiology@pathlab.co.nz.
A further document will be produced summarising the results of any clinical feedback received, along with a decision as to whether to proceed.
Identifying and managing infection in wounds is an important aspect of clinical practice. However, many issues relating to the aetiology of infection and the sampling of wounds remain controversial, with limited expert consensus.
The diagnosis of wound infection is essentially a clinical diagnosis, with laboratory testing used to provide further information to guide management, particularly when the use of systemic antibiotics is deemed appropriate.
It is generally only necessary to swab a wound if there are clinical signs of infection and the wound is deteriorating, increasing in size or failing to heal. Swabbing a wound that is not infected results in the unnecessary identification and analysis of organisms which are colonising the wound, rather than causing an infection.
Below are what we would regard as acceptable and unacceptable clinical details:
(when clinically infected)
The laboratory receives over 500 urine samples per day for microbiological testing. Often there are few clinical details on this particular sample type to provide a rationale for testing. Clinical details are particularly important amongst patient cohorts who have a high prevalence of asymptomatic bacteriuria such as older people, rest home residents, patients with long term urinary catheters. Reporting by the microbiology laboratory of urine culture results in patients who do not have specific symptoms drives unnecessary antibiotic prescribing and increased antibiotic resistance.
A brief summary of the patient’s specific symptoms, accompanied by any other useful information such as pregnancy, immunocompromising conditions, current antibiotics, allergies, etc. all contribute to how the sample is processed in the laboratory, what susceptibilities are performed and how the result is reported back to the requestor.
“?UTI”/”UTI” or similar will be accepted for testing. However, this is essentially a diagnosis as opposed to relevant clinical details and we strongly discourage this practice. The patient's specific symptoms should be stated as detailed above. This helps the laboratory decide between an uncomplicated and complicated UTI and whether the upper renal tract may be involved. These decisions affect which antibiotics are tested, whether an antibiotic is interpreted as susceptible or resistant and which susceptibility results are reported back to the requestor.
Bacterial culture of sputum samples suffers from both poor sensitivity and specificity, leading to sub-optimal antimicrobial stewardship. Sputum samples undergo initial Gram stain evaluation, looking for the presence of leucocytes and epithelial cells, which will dictate whether the sample is suitable for culture. However, even with this preliminary step, the yield of pathogens from sputum samples is very low. Specificity is also poor because positive culture results may represent normal nasopharyngeal tract flora.
The following lists the clinical circumstances in which sputum samples sent to the laboratory will be deemed acceptable or unacceptable:
In summary, sputum samples on immunocompetent patients from the community who simply present with cough with no other complicating factors will not be accepted. International guidelines do not support the use of sputum cultures in non-hospitalised patients with acute bronchitis or mild community acquired pneumonia.
https://pathways.nice.org.uk/pathways/pneumonia#path=view%3A/pathways/pneumonia/assessment-of-community-acquired-pneumonia.xml&content=view-node%3Anodes-microbiological-tests
https://copdx.org.au/wp-content/uploads/2019/02/COPDX-V2-56-Dec-2018-Web.pdf