Gary Ruiz

Feeding intolerance due to connatal tuberculosis in a prematurely born infant

A prematurely born infant had three episodes of feeding intolerance in the first three weeks after birth. In the post-partum period, his mother, who was from the Ukraine, had a respiratory arrest; unusually, a high-resolution computerised tomograph demonstrated miliary tuberculosis (TB). As a consequence, and due to the continuing ill health of the infant, gastric aspirates were sent from the infant. Acid fast bacilli were seen on microscopy. Variable nucleotide tandem repeat analysis of acid fast bacilli facilitated the rapid diagnosis of connatal TB. We conclude that connatal TB should be considered in a prematurely born infant poorly responsive to standard management and whose mother falls into a high-risk group.

Kawasaki Disease presenting with intussusception: a case report

A 3 yr old boy presented with abdominal pain, fever and red jelly stools. Intussusception was diagnosed and effectively reduced with air insufflation. However, despite an improvement in his clinical condition, the child remained febrile and miserable; 5 days later he developed characteristic signs of Kawasaki disease and was treated with intravenous immunoglobulin and high dose aspirin with good results. Intussusception prior to the typical features of Kawasaki disease has not been described previously in the English literature. This case illustrates a novel presentation of Kawasaki disease.

G488 Pulse oximetry is an unreliable measure of haemoglobin oxygen saturation as calculated by earlobe blood gas co-oximetry in ambulatory paediatric sickle cell disease patients

Aim Accurate measurement of Hb saturation is essential in the care of children with sickle cell disease (SCD). The gold standard of Hb saturation measurement is by ABG with co-oximetry. Minute-by-minute changes are detected with pulse oximetry (SpO2). SpO2 shows good correlation to ABG co-oximetry in well patients with normal Hb. SCD patients represent a different population: previous small studies have shown discrepancies in calculated ABG and SpO2 Hb saturations. SpO2 may be falsely low due to high carboxyhaemoglobin and metahaemaglobin levels following heme catabolism, or high due to hyperbilirubinaemia. Both occur in acute and chronic haemolysis. With treatment decisions in acute and ambulatory settings driven by bedside SpO2, inaccuracies can result in mismanagement. Earlobe blood gas (EBG) co-oximetry is an alternative better tolerated method of measuring Hb O2 saturation in arterialised capillary blood (SaO2), with good correlation to ABG measurements. We sought to investigate the correlation between SpO2 and SaO2 measured by EBG co-oximetry in ambulatory SCD children. Methods We retrospectively reviewed paediatric SCD patients attending a UK tertiary sickle-respiratory clinic from February 2012–August 2015, and who had simultaneous EBG and SpO2 measurements. Positive difference results from SpO2 value greater than EBG SaO2. Results We identified 39 simultaneous paired SaO2 and SpO2 readings from 33 patients (52% male, median age 10years, range: 5–17). Mean difference between readings was –0.7% (Figure 1 and 2). In 23% of cases, difference was >±2%. SaO2 was overestimated in one-third and underestimated in two-thirds. Of 17 hypoxaemic measurements (SpO2 <94%), only 76% had SaO2 <94% (means: SpO2 90.3%, SaO2 92.1%; difference –1.8%; CI –3.3 to –0.4, p = 0.02) (Table 1). In terms of determining hypoxia based on a cut-off of 94%, SpO2 had sensitivity 85%, specificity 100%, PPV 100% and NPV 76%.Abstract G488 Figure 1 Bland-Altman plot showing mean simultaneous O2 saturations by EBG and pulse oximerty and difference between results. Unbroken line indicates mean difference (-0.7%) and broken lines indicates limits of agreement (-5.6 to +4.3%) (mean ± 2SD). Shaded region represents a difference of ±2%, the accepted error rangeAbstract G488 Figure 2 Simultaneous SpO2 and SaO2 measurements. Straight line indicates SpO2 = SaO2 Abstract G488 Table 1 Conclusion Pulse oximetry as a measure of Hb oxygen saturation was inaccurate in a significant proportion of ambulatory SCD children. SpO2 tended to be lower than actual SaO2 as measured with EBG, with SpO2≥94% more likely to predict true result than SpO2 <94%. In patients with SpO2 <94%, there was a significant difference in calculated Hb saturation. EBG should be used more widely as an accurate means of detecting changes in arterial Hb oxygen saturation.

Cystic fibrosis newborn screening: outcome of infants with normal sweat tests

Newborn babies positively screened for cystic fibrosis (CF) (high serum immunoreactive trypsin (IRT) with DNA analysis) are referred for a diagnostic sweat test, which may be normal (sweat chloride <30 mmol/L). Unless two gene mutations are identified during Newborn screening (NBS), the babies are discharged from follow-up. We wished to check that none had subsequently developed symptoms suggestive of CF. We retrospectively reviewed patient notes and contacted general practitioners of all babies with a negative sweat test, conducted in one of the four paediatric specialist CF centres in London, over the first 6 years of screening in South East England. Of 511 babies referred, 95 (19%) had a normal sweat test. Five (5%) had CF diagnosed genetically, two of them on extended genome sequencing after clinical suspicion. Eleven (12%) were designated as CF screen positive inconclusive diagnosis (CFSPID); one of the five CF children was originally designated as CFSPID. Seventy-nine (83%) were assumed to be false-positive cases and discharged; follow-up data were available for 51/79 (65%); 32/51 (63%) had no health issues, 19/51 (37%) had other significant non-CF pathology. These results are reassuring in that within the limitations of those lost to follow-up, CF symptoms have not emerged in the discharged children. The high non-CF morbidity in these children may relate to known causes of high IRT at birth. Clinicians need to be aware that a child can have CF despite a normal sweat test following NBS, and if symptoms suggest the diagnosis, further testing, including extended genome sequencing, is required.

P43 Factors influencing length of chest drain insertion in children with empyema

Introduction Many factors might influence length of chest drainage (LOCD) when managing parapneumonic effusions/empyema including effusion size, septations, extent of pneumonia, presence of air leaks, pathogen virulence, fibrinolytic therapy with urokinase and local policies. UK guidelines recommend using the same fixed volumes for infants and for all children older than a year regardless of size. This preliminary retrospective survey was undertaken to determine whether there may be a signal to suggest an optimal urokinase volume based on weight which might warrant a controlled study. Objectives To investigate clinical factors that affect length of chest drain insertion (LOCD) in children with empyema and to examine if there is an optimal urokinase dosing based on patient’s weight would affect the LOCD. Methods We conducted a retrospective review of clinical data from 52 children with empyema admitted to our centre between January 2015-December 2016. Chest drains were in place for a range of 2 to 12 days with a median of 5 days. We conducted a comparison of these data between the group of patients who required chest drain insertion for ≤5 days and those ≥5 days. We also grouped the patients into two levels of urokinase dose based on patients weight to create a frequency table and eventually to look if a certain dose is associated with a shorter LOCD. Results The median LOCD insertion in our group was 5 days. Patients with a longer LOCD showed a trend to be younger and had a higher WCC, but this was not statistically significant. There were no statistically significant difference in the dose/kg of urokinase and LOCD. Conclusion Our study did not show weather a certain urokinase dose based on weight would affect the LOCD. There were no other clinical indicators among our population that can predict the LOCD. Abstract P43 Table 1 LOCD≤5 days n. (28) LOCD>5 days n.(22) P value Gender (Male) 12 11 0.77 Age (Mean) 5.36 2.90 0.38 O2 requirement 19 17 0.58 CRP 231 (43–346) 241 (96–440) 0.54 WCC 16.35 (0–59) 20.18 (7.99–96.09) 0.22 US fluid depth (mm) 34.6 (18.9–85) 30 (16–74) 0.37 Urokinase U/Kg 2278 (404–3922) 2667 (317.5–5405) 0.42 Frequency of patients on low dose Urokinase (<2000 u/kg) 9 9 0.76 Frequency of patients on high dose Urokinase (≥2000 u/kg) 18 13 0.76

Fifteen-minute consultation: a structured approach to the management of chronic cough in a child

Coughing is a primary pulmonary defence mechanism that enhances clearance of secretions and particles from the airways and protects against aspiration of foreign materials. Coughing may affect 30% of children at any given time (1). Many are healthy children but some may have serious underlying disease. Childhood cough accounts for a large number of consultations and 80% of families who are referred to a paediatric respiratory clinic for chronic cough have sought medical advice five times or more (2). The majority of childhood coughs are secondary to an acute respiratory tract infection and will improve once the infection resolves, usually within 1 to 3 weeks. With pre-school children who may experience between 6 and 10 respiratory infections a year differentiating acute recurrent cough from chronic cough is key (Table 1). Chronic cough can significantly impact a family’s quality of life, as it affects the child’s sleep, school attendance and play. Parents experience distress and anxiety, worrying that the cough may lead to long-term chest damage or even death (3). This article aims to guide clinicians through the assessment of the child with a chronic cough. It will discuss identifying causes, use of first line investigations, initiating appropriate management and addressing parental anxiety and exacerbating factors (4,5).

P94 Effect of Hydroxyurea on Nocturnal and Awake Oxygen Saturation in Children with Sickle Cell Disease

Introduction Sickle cell disease (SCD) causes lifelong morbidity and reduced life expectancy. Resting hypoxaemia and intermittent nocturnal oxygen desaturation are often seen in children with SCD, which may contribute to morbidity associated with vaso-occlusive episodes. Treatment with hydroxyurea reduces the frequency and severity of vaso-occlusive episodes1 but the impact of hydroxyurea on oxygen saturation and sleep apnoea is unknown. Objective To look for any difference in baseline oxygen saturation asleep and awake and the frequency of intermittent nocturnal desaturation after starting hydroxyurea in children with SCD. Methods A retrospective review of children who were commenced on hydroxyurea between March 2006 and July 2014 attending two UK sickle-respiratory clinics. Data was collected from overnight sleep studies and averaged pulse oximeter spot check recordings in clinic notes when awake from a) 6 months before starting hydroxyurea and b) up to 2 years after. Lung function and haemoglobin changes were also noted over the same time periods. Results Forty six children (25 male) with a median age of 10 years (range 5–19 years) were started on hydroxyurea. Haemoglobin and HbF rose significantly on hydroxyurea as expected (Table 1). After starting hydroxyurea the average overnight oxygen saturation increased from median of 93.5% to 95.2% (p = 0.01) and the median daytime spot oxygen saturation rose from 93.5% to 96.3% (p = 0.001). There was no significant change in the median intermittent nocturnal 3% oxygen desaturation index (ODI), nocturnal PCO2 or spirometry.Abstract P94 Table 1 Change in haematological and respiratory indices with hydroxyurea BeforeMedian (Interquartile range) On HydroxyureaMedian (Interquartile range) *P value Hb (g/L) 76 (69.5–86.5) 83 (72.7–87.7) 0.04 HbF (%) 6.1 (3.7–12.9) 8.8 (6–16) <0.001 Average overnight SpO2 (%) 93.5 (88–97) 95.2 (93–98) 0.01 Nadir overnight SpO2 (%) 84 (77.4–89) 87 (83–91) 0.009 3% ODI overnight (events/hour) 3.0 (1.5–5.2) 2.8 (1.1–4.6) 0.08 Mean overnight PCO2 (kPa) 5.7 (4.7 -6.2) 5.5 (5.2 -6.0) 0.3 Spot daytime SpO2 (%) 93.5 (91–97) 96.3 (94–98) 0.001 % FEV1 70 (61.5–83.5) 73 (68–88) 0.6 *P values based on Wilcoxon matched-pairs signed rank test. Conclusion In children with SCD, the use of hydroxyurea was associated with a significant increase in awake and nocturnal baseline oxygen saturation, but no change in intermittent nocturnal desaturation indices or lung function. This preliminary data suggests that improving oxygen saturation may be an important outcome of hydroxyurea therapy with potential benefits in reducing not only vaso-occlusive crises but future respiratory morbidities. This hypothesis would need to be tested by a prospective multicenter trial. Reference 1 Charache S, Terrin ML, Moore RD, et al. Effect of hydroxyurea on the frequency of painful crises in sickle cell anemia. Investigators of the Multicenter Study of Hydroxyurea in Sickle Cell Anemia. N Engl J Med 1995;332:1317–1322