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The 64th Bubble Wrap


With millions upon millions of journal articles being published every year, it is impossible to keep up.  Every month we ask some of our friends from PERUKI (Paediatric Emergency Research in the UK and Ireland) to point out something that has caught their eye.

Article 1: How accurate is dipstick urinalysis in diagnosing UTIs in febrile infants?

Waterfield T, Foster S, Platt R On behalf of Paediatric Emergency Research in the UK and Ireland (PERUKI), et al. Diagnostic test accuracy of dipstick urinalysis for diagnosing urinary tract infection in febrile infants attending the emergency department. Archives of Disease in Childhood. Published Online First: 24 August 2022. doi: 10.1136/archdischild-2022-324300

What’s it about? 

The most common serious bacterial infection (SBI) in infants under 90 days old is a urinary tract infection (UTI). NICE advises lab testing of urine for children in this age range to detect UTI if they present as febrile. The authors of this study aimed to determine the accuracy of point of care (POC) testing with urine dipsticks as rule-in or rule-out criteria for UTI.

The study was a retrospective chart review of 275 febrile infants under 90 days old across eight paediatric emergency departments in the UK and Ireland. Data included lab and POC results for urine samples collected with a clean catch or catheterization. UTI was confirmed by the growth of a single organism (excluding contaminants) with associated pyuria. The authors used microscopy results to determine the sensitivity and specificity of different urine dip results, aiming for the highest sensitivity and specificity possible.

275 infants were included, as several were out of the age range or had missing data. Around half were female, and the median age was 51 days. 13% had a confirmed UTI, 92% of which were E. coli.

A trace of leucocytes was the most sensitive test for the detection of a UTI (0.84 sensitivity, 0.73 specificity), and when this was increased to 1+ of leucocytes, the sensitivity dropped to 0.82, but specificity increased to 0.82.

A trace of nitrites was the most specific test for the detection of a UTI (0.91 specificity and 0.42 sensitivity). Increasing this to 1+ or more nitrites increased specificity but reduced sensitivity.

Combining leucocyte and nitrite presence increased specificity but massively reduced sensitivity. Looking for either/or had similar specificity and sensitivity as looking for each component individually.

Why does it matter?

Point-of-care urine dip can be used as a rule-in or rule-out test for UTI. This is important as it means febrile infants may avoid invasive testing such as lumbar puncture if a UTI can be ruled in and presumed to be the cause of their fever.

Clinically Relevant Bottom Line :

Authors have shown that the absence of leucocytes on urine dip has a sensitivity of 0.82 for excluding a UTI. Even a trace of nitrites has a 0.91 specificity to rule in a UTI in infants under 90 days old.

Reviewed by: Cameron Morrice

Article 2: Is end-tidal carbon dioxide an acceptable surrogate for arterial carbon dioxide in children with traumatic brain injury?

Yang JT, Erickson SL, Killien EY, Mills B, Lele AV, Vavilala MS. Agreement Between Arterial Carbon Dioxide Levels With End-Tidal Carbon Dioxide Levels and Associated Factors in Children Hospitalized With Traumatic Brain Injury. JAMA Netw Open. 2019;2(8):e199448

What’s it about? 

In a study of mechanically ventilated children admitted to the Paediatric Intensive Care Unit (PICU) with traumatic brain injury (TBI), Yang et al. examined the relationship between the end-tidal carbon dioxide (ETCO2)and arterial carbon dioxide (PaCO2) within the first 24 hours. The closest ETCO2 value within 30 minutes of a PaCO2 value was recorded (with over 40% of these being within 10 minutes of each other). The agreement (how close the values were to each other) and correlation (how changes in one of the values can be used to predict changes in the other) of the PaCO2 and EtCO2 measurements were explored.

Although the inclusion of 137 children is a limited sample size, it is larger than comparable studies in adults and conducting the study as a prospective cohort study is a strength which allowed 445 paired PaCO2-ETCO2 measurements to be analysed.

Yang et al. found that less than half of all PaCO2-ETCO2 samples agreed (187/445 (42%)), and the correlation was only moderate (r = 0.45). The largest variation was seen in the first 8 hours, and the development of Paediatric Acute Respiratory Distress Syndrome (PARDS) was associated with a lower likelihood of all PaCO2-ETCO2 agreement. On average, PaCO2 was 2.7mmhg higher than ETCO2. The study used the Pearson correlation coefficient, and there was only a moderate correlation between ETCO2 and PaCO2.

This study only looked at one centre and did not look at correlations after the first 24 hours.

Why does it matter? 

Changes in CO2 can affect outcomes in children with TBI. A high PaCO2 can cause acidosis and cerebral vasodilation, increasing intracranial pressure, whilst a low PaCO2 causes alkalosis and cerebral vasoconstriction, which can lead to cerebral ischaemia. Arterial sampling can be challenging in children, and complications are not uncommon. The EtCO2 is a non-invasive surrogate for PaCO2 and is often used to guide ventilatory strategies.

The findings by Yang et al. suggest that EtCO2 is not a reliable substitute for PaCO2 in the early management of TBI.

Clinically Relevant Bottom Line:

ETCO2 should not be used as a substitute for PaCO2 to guide ventilatory strategies during the first 24 hours of PICU admission in children with TBI. Correlation is the worst in the first 8 hours after admission, and poor correlation early in the admission may be associated with PARDS.

Reviewed by: Owen Hibberd

Article 3: Extra-axial haemorrhages in young children with skull fractures: abuse or accident?

Wallace J, Metz JB, Otjen J, et al. Extra-axial haemorrhages in young children with skull fractures: abuse or accident? Archives of Disease in Childhood 2022;107:650-655

What’s it about?

Extra-axial haemorrhage (EAH) refers to bleeding inside the skull but outside the brain parenchyma and encompasses extradural, subdural, and subarachnoid bleeding. EAH is associated with accidental and non-accidental injury (NAI), so the authors aimed to find factors which differentiated these mechanisms of injury and, therefore, helped to detect abusive injury.

Notes and imaging for children under four years of age with EAH were reviewed from 2011 and 2014, with characteristics such as initial GCS, soft tissue swelling, type/size of haemorrhage and mechanism of injury also recorded. Univariate statistics were used to compare characteristics across accidental and non-accidental mechanisms of injury, and significantly different characteristics were assessed using multiple linear regression (MLR) to determine their predictive value. The presence of a subdural haemorrhage was associated with an increased odds ratio of abusive head trauma in MLR analysis. Among 227 subjects, 86 (37.9%) had EAHs. EAH was present in 73 (34.8%) accidental and 13 (76.5%) abusive injuries. 69% of accidental EAHs were localised solely at fracture sites vs 38% abuse. This paper noted that abused children were more likely to suffer from loss of consciousness after the initial impact. Multifocal subdural haemorrhages were less common in accidents than in abuse.

Widespread subdural haemorrhages were statistically less common in minor accidental injury than in abuse but did not differ for major accidents vs abuse. There were limitations, such as the lack of data for some measures within the sample. There was also a small number of cases, which may have prevented significance from being proven in some of the subgroup analyses.

Why does it matter?

EAH is associated with accidental and non-accidental head trauma, but identification of abusive head trauma is important as 28% of patients in whom NAI is missed go on to be reinjured.

Clinically Relevant Bottom Line:

Accidental injury can cause skull fractures and EAH. EAH, however, when associated with a fracture, increases the possibility of abusive head trauma. The study, however, clearly states the EAH associated with a skull fracture is not enough to diagnose abuse and instead should stimulate further investigation.

Reviewed by: Cameron Morrice

Article 4: Do sterile gloves matter when suturing?

Zwaans et al Non-sterile gloves and dressing versus sterile gloves, dressings and drapes for suturing of traumatic wounds in the emergency department: a noninferiority multicentre randomised controlled trial Emerg Med J Published online 26 July 2022

What’s it about?

This was a multicentre randomized controlled trial testing for non-inferiority of non-sterile gloves and dressings vs sterile gloves, dressings, and drapes for suturing of traumatic wounds. The study enrolled 1480 patients in 3 adult EDs in The Netherlands. The observed wound infection rate in the non-sterile group was 5.7% (95% CI 4.0% to 7.5%) vs 6.8% (95% CI 5.1% to 8.8%) in the sterile group. The mean difference in the wound infection rate of the two groups was `1.1% (95% CI −3.7% to 1.5%). The wounds were prepared the same way, with both arms undergoing decontamination of large particles, running under tap water, and disinfecting with chlorhexidine.

Recruitment ceased prior to the planned sample size, so the results need to be interpreted with caution. In both groups, the infection rate was higher than quoted in previous literature. However, the results showed that using non-sterile gloves and dressings was non-inferior to sterile counterparts- therefore, there was unlikely to be a large difference in using non-sterile vs sterile equipment.  

Why does it matter?

Sterile gloves and drapes require more time and additional cost to emergency visits. They are less available in resource-poor settings and complicate the procedure by requiring an assistant who is not sterile. The wounds we see in the emergency department are caused in non-sterile environments, with non-sterile implements- which differs greatly from the sterility of the operating theatre environment.

Clinically Relevant Bottom Line:

The repair of traumatic lacerations that are present in the ED should not be considered a sterile procedure. Based on this study, sterile gloves and drapes does not affect infection rates.

Reviewed by: Justin Hensley

Article 5: How safe are paediatric emergency departments?

Plint AC, Newton AS, Stang A, et al. How safe are paediatric emergency departments? A national prospective cohort study BMJ Quality & Safety Published Online First: 19 July 2022. doi: 10.1136/bmjqs-2021-014608

What’s it about?

This was a prospective multi-centre cohort study looking at adverse events following presentation to the nine tertiary paediatric emergency departments in the Paediatric Emergency Research Canada network. Adverse events may be broadly defined as unintended harms related to healthcare rather than a patient’s underlying medical condition.

Their primary outcome was an AE within 21 days of presentation related to care provided at that visit. Follow-up data was gathered via a structured telephone interview on days 7, 14 and 21 after the presentation.

6376 children were enrolled with 6015 having adequate follow-up. 179 of these 6015 experienced an AE related to their care. This equates to 1 in 33 children who presented to a paediatric emergency department (ED). 139 of these 179 patients (77.6%) were deemed to have experienced a preventable AE.

The most common adverse were related to management issues, diagnostic issues, and adverse medication effects. The authors found that the increased risk of preventable AE was significantly associated with increasing age, having a chronic condition, and increasing time to physician assessment and treatment in the acute care area of the ED. Children with low acuity or high acuity presentations were found to have an increased risk of adverse events compared with mid-acuity presentations.

An important group that was excluded were patients in whom there was a significant language barrier- this needs to be considered when interpreting the results as it is an important group.

Why does it matter?

The number of children treated in emergency departments is increasing in many countries worldwide. High-acuity patient presentations and increasing patient attendance make EDs a challenging place to provide paediatric care. It is important that we recognise the risk of AE associated with our care and identify those at higher risk of AE.

Clinically Relevant Bottom Line:

As clinicians, we need to be cognizant of the risk of, mostly preventable, adverse events related to our care in the ED and recognise those most at risk of them.

Reviewed by: Freya Guinness

If we have missed out on something useful or you think other articles are absolutely worth sharing, please add them in the comments!

That’s it for this month. Many thanks to all of our reviewers who have taken the time to scour the literature so you don’t have to.

All articles reviewed and edited by Vicki Currie


  • Vicki is a Paediatric Registrar in the West Midlands in the UK , starting PEM in September 2021. Vicki is passionate about good communication in teams and with patients along with teaching at undergraduate and postgraduate level. When not editing Bubble wrap Vicki can be found running with her cocker spaniel Scramble or endlessly chatting with friends.


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