Are well infants with urinary tract infections at risk of bacteraemia? Elspeth Ferguson ST6 Paediatrics

Talk Outline Set the scene PICO Question Paper overview CASP analysis Relating findings to our practice

Clinical Scenario 6 week old baby Vomiting Looks well, no fever, obs normal Urgent urine microscopy 3+ Wbc What do you do?

Current Guidance NICE UTI <3mth: –Refer immediately to paeds specialist –Treat with parenteral abx in line with NICE feverish illness in children SCH UTI <3mth: –Follows NICE guidance as above

PICO Question Patient – Infant <3mth with UTI Intervention – Afebrile, looks well Comparator – Febrile, unwell Outcome - Bacteraemia

Paper Overview Retrospective study Tertiary Paediatric Hospital, Barcelona, Spain 7yr study period Sept 2006-May 2013 Infants days diagnosis UTI UTI =Organism visualised on gram stain AND 50,000 colony forming units/ml of single organism from catheter specimen

Outcomes Risk of bacteraemia Related to: –Age –Medical history –Fever –PAT –Markers of infection

CASP Analysis

Did the study address a clearly focused issue? Did the authors use an appropriate method to answer the questions?

Were patients recruited in an acceptable way? Based on coded diagnosis of UTI Organisms on microscopy AND positive culture Positive culture >50000 colony forming units per ml Excluded if no blood culture collected ?Infants at high risk of UTI with complications eg posterior urethral valves

Was exposure measured accurately? All information collected retrospectively from electronic records Fever –measured at home or presentation General appearance based on Paediatric Assessment Triangle (PAT) at presentation

Outcome Presence or absence of bacteraemia –Positive blood culture with same organism isolated in urine

What about limitations? Selection bias Missing data Review of records and interpretation Low rates of bacteraemia Longer term complications of UTI not mentioned

What are the results? 10/350 infants had bacteraemia (2.9%) 1/350 ICU admissions (had RSV +ve bronchiolitis) No acute complications of UTI 19/350 underwent LP, none positive

Risk of bacteraemia vs Risk factors Risk FactorNumber +ve bld cultures P valueOR (95% CI) Age days8/182 (4.4%) ( ) days2/168 (1.2%) Medical History High risk2/74(2.7%) ( ) Not high risk8/276 (2.9%) FeverFebrile8/273(2.9%) ( ) Afebrile2/77 (2.6%) PATAbnormal3/12 (25%) ( ) Normal7/338 (2.1%)

Results Continued Procalcitonin higher in those with bacteraemia 9.2ng/ml vs 0.3ng/ml p=0.031 No differences for WCC or CRP

Study Conclusions Well infants with UTI and procalcitonin <0.7 could be considered for outpatient management and appropriate follow-up Sensitivity 88.9% Negative predictive value 99.5% 1/187 (0.5%) well infants would have been missed using this criteria

Do we believe the results? What about those we thought had UTI at presentation but left with a different diagnosis?

Can the results be applied to the local population? Probably a similar patient demographic However: –Catheter specimens and organism comment on microscopy –Role of procalcitonin, CRP/WCC not helpful –What about those who we think have UTI at presentation?