Asthma in Pediatric Sickle Cell Acute Chest Syndrome: In An Inner City London Hospital

Acute Chest Syndrome (ACS) is the second most common cause of hospitalisation in patients with Sickle Cell Disease (SCD) and up to 25% of those admitted will require intensive care management. ACS is a leading cause of death in SCD. It may also play a role in the development of chronic lung disease in SCD patients and the prevalence of Asthma in SCD patients is high. The pathogenesis of ACS is complex. Previous work has suggested a relationship between asthma and higher risk of ACS in children with SCD. Data in the UK is limited. Our aim therefore was to describe the presentation, course and outcome of ACS in our local SCD pediatric population, compared with those children who had ACS with SCD and physician diagnosed Asthma (Asthma).

Methods: The data collection took place at The Evelina Children’s Hospital, which is part of St Thomas’ Hospital, a large teaching hospital in Central London, England. There are over 400 children with SCD registered, and around 30 new SCD births per year. A retrospective analysis of patient hospital electronic and paper records was performed of 63 ACS presentations over a three year period from 2003 to 2006. Inclusion in the study required a new infiltrate on chest radiograph plus acute respiratory symptoms in a patient with SCD under the age of 16 years. The group included 16 (25%) presentations in children with SCD and Asthma.

Results:No Known Asthma 47 Presentations; Mean age 6.2 yrs (range 1–15yrs); HbSS 87%, HbSC13%; Previous ACS 26% (n=12); Mean length of stay 5.4 days (range 1–27); Mortality 0; Mean C-Reactive protein (CRP) on admission 70 (normal <5); Mean oxygen saturations on presentation 92% in air (40% of patients presented with saturations <92% in air)

Physician Diagnosed Asthma 16 Presentations; Mean age 4.6 (range 1–15yrs); HbSS 94%, HbSC 6%; Previous ACS 63% (n=10); Mean length of stay 5.4 (range 2–14); Mortality 0; Mean CRP on admission 41; Mean oxygen saturations on presentation 92% in air (50% of patients presented with saturations <92% in air)

DISCUSSION:Demographics: Comparable in terms of age and haemoglobin genotype. Presentation: Patients with asthma were more likely to have had previous ACS. Children with asthma presented with a lower CRP. Treatment: The treatment in both groups including the use of blood transfusion, and need for transfer to intensive care were comparable. However there was an observed difference in the use of inhaled bronchodilators (non asthma 21% v asthma 50%). Steroids were rarely used (4%) to treat the patients who did not have a pre-existing diagnosis of asthma, however were used to treat most (94%) of those patients with asthma. Outcome: Length of stay was comparable, no deaths in either group.

CONCLUSION: Although patients in our study group with asthma had a higher frequency of previous ACS episodes, we did not demonstrate that patients with asthma suffer a more severe course of illness.