Page 191 - Registrar Orientation Manual 2016

Reference:
Effective date:
2015
Expiry date:
2018
Page:
17 of 28
Title: Laboratory Testing Guidelines (DRAFT)
Type:
Clinical Guideline
Version:
01
Authorising initials:
We also recommend:
If endocarditis is a possibility do repeated cultures (x3) before starting antibiotics and only start antibiotic treatment after discussing with a SMO.
If endocarditis is not suspected do 2 sets (4 bottles) of blood cultures simultaneously.
Except in patients with staphylococcal bacteraemia do not repeat cultures after starting antibiotics because the fever continues. If 2 sets have been done that is adequate.
As a general rule (except in suspected endocarditis) do blood cultures only if patients with sepsis do not have a clear cause of their infection and are sick enough to require IV antibiotics.
Sepsis = confirmed or suspected infection and 2 or more SIRS criteria:
T >38C or <36C, HR>90, RR>20 or PaCO2<32mmHg, WBC>12,000 or <4000 or “left shift” Severe sepsis = sepsis + new organ dysfunction +/or hypoperfusion +/or hypotension
MSU/CSU ($18)
Urine cultures cost over $600,000 a year and many tests are not clinically indicated.
Choosing Wisely has the following:
Do not order urine cultures for healthy patients with uncomplicated urinary tract infection.
Do not perform surveillance urine cultures (or treat bacteriuria) in elderly patients in the absence of symptoms or signs of infection.
Avoid surveillance cultures for screening and treatment of asymptomatic bacteriuria in children.
We also recommend:
Do not do a MSU unless there are symptoms of urosepsis or sepsis of uncertain cause.
Do not request a routine MSU in a confused or unwell elderly patient who has another clear cause or causes of their delirium or un-wellness.
Do not repeat the MSU if it was contaminated and antibiotics have already been given.
Do not do a CSU unless a catheterised patient has features of sepsis.
Do not do urine culture in suspected kidney disease without sepsis (do microscopy alone)
Note in the elderly asymptomatic bacteriuria is common (up to 30%) and should not be treated.
Catheter colonisation is the norm; treatment is only indicated if a patient has features of sepsis.
Patients with undiagnosed kidney disease (new AKI or CKD and a raised creatinine, haematuria or proteinuria) will require urine examination for casts, cells and protein but do not require culture.
Sputum Culture
Sputum cultures cost over $160,000 a year. They are not indicated in every patient with a cough!
We recommend:
Do not do routine sputum cultures in every patient with a cough (be selective).
Results of most sputum cultures rarely change management. Sputum cultures should be done selectively (for example in patients with bronchiectasis or COPD but not in asthma or bronchitis).
Stool specimens ($55 and C difficile $39)
Choosing Wisely only have one recommendation:
Do not repeat stool examination for C difficile to confirm “cure” if symptoms have resolved.