Acute Thoracic Syndrome in Sickle Cell Children at the Pediatrics Department of Donka National Hospital

Introduction: Acute thoracic syndrome is the appearance of a new pulmonary infiltrate on radiology associated with fever, desaturation or respiratory signs. It is the second leading cause of hospitalization and the first cause of death in sickle cell patients. It is an acute pulmonary complication whose pathophysiological mechanisms are still poorly understood. This study aims to study the epidemiological, clinical, therapeutic and evolutionary aspects of Acute Chest Syndrome in children at the Pediatrics Department of Donka National Hospital. Method: This is a prospective study of descriptive type for a period of 6 months from February 19 to August 19, 2019 on patients with sickle cell disease who developed an ATS in the pediatrics department of Donka National Hospital. Epidemiological, clinical, therapeutic and evolutionary data were stu-di ed and proportionate data were calculated. Results: The frequency of ATS was 39%. The mean age of our patients was 9.83 years with the extremes of 4 and 16 pediatric population. Its treatment is symptomatic and must be started early. Emphasis must be placed on prevention to prevent or limit its occurrence.


Introduction
Sickle cell disease is an autosomal recessive genetic disease linked to a hemoglobin abnormality, characterized by the replacement of glutamic acid by valine on the β chain [1].
It is a real public health problem in the world because of its morbidity and mortality, especially in childhood. According to the WHO, 2 to 3 million children with sickle cell disease are born in the world every year. It is the most common genetic disease and mainly affects black populations [2].
Among acute complications, acute thoracic syndrome (ATS) is the second leading cause of hospitalization and the first cause of death in patients with sickle cell disease [5].
Ballas and Coll define it as the appearance of a new pulmonary infiltrate in radiology with fever, desaturation or respiratory signs [6].
It is an acute pulmonary complication whose pathophysiological mechanisms are still poorly understood [7] [8].
Given the complexity of its mechanisms of action and the difficulty in identifying a precise etiological factor in many patients, the management of ATS is non-specific and symptomatic [9].
In the United States, Castro. O et al. in a national multicenter study group found an incidence of 29%. Of the 3751 patients enrolled, 1085 had an x-ray compatible with an ATS. The incidence was higher in homozygous SS and thalassemia β0 and lower in patients with hemoglobin SC and β+ [10].
In a study conducted in 2012 by S. Bertholdt  In Guinea, Hounsa. T Alfred at Donka National Hospital in his thesis work found 4.4% [12].
The aim of this study was to study the epidemiological, clinical, therapeutic and evolutionary aspects of ATS in children in the pediatrics department of the

Methods
This is a prospective study of descriptive type for a period of 6 months from February 19 to August 19, 2019 carried out at Donka National Hospital. It included all children with sickle cell disease in the pediatric ward received for ATS (Acute Chest Syndrome) presenting: fever, respiratory signs (cough, chest pain, dyspnea, rales), pulmonary infiltrate on X-ray. All children with sickle cell disease who presented with ATS during hospitalization.
A structured survey form was used to collect socio-demographic, clinical and therapeutic data from the children, which were entered and processed using EPI info 7.2 software and then presented in the form of results using Word and Excel software from the Office 2010 pack.
The anonymity and confidentiality of the information collected were preserved.

Results
Out of 64 patients with sickle cell disease seen in the pediatrics department of Donka National Hospital during our study period, we collected 25 cases of ATS, i.e. a frequency of 39%. The age group of 6 -10 years was the most affected at 66.7%; the mean age was 9.83 years with extremes of 4 years and 16 years. Male sex predominates, with 64% of cases with a sex ratio of 1.77. The average age was 9.83 with extremes of 4 and 16 years. Household mothers were the most represented in 56% of cases, while fathers who were civil servants were the most represented in 28% of cases. Socio-demographic characteristics are shown in Table 1. Out of 25 patients who developed Acute Chest Syndrome, 24 had not been vaccinated, or 96%; only 1 case (4%) had received the specific vaccines (Typhim vi, Pneumo 23, and Meningo) ( Table 2). Fever was the main clinical manifestation encountered during our study with a frequency of 72% followed by hepatomegaly 68%, cough and chest pain had 64% respectively. Rarer manifestations were headache 8% and jaundice 4% (Table 3).
On examination, we found crackling and snoring rales that were 52% and 8% respectively (Table 4). During our study, 72% of the patients had hemoglobin levels between 6 and 10 g/dl and only 28% (7/25) had hemoglobin levels below 6 g/dl ( Table 5).
The average length of stay of patients in our department was 5.28 and the 5 to 7 day period was the most represented with 72% of the cases ( Table 6).
All of our patients were on folic acid prophylaxis and were treated with analgesics, third generation cephalosporin and hyperhydration.
The most commonly used analgesic class was Tier I and Tier II. 96% of our patients received a blood transfusion of packed red blood cells (Table 7). We noted a favorable evolution in 24 cases, i.e. 96%. However, we recorded one (1) or 4% deaths (Table 8).      States found fever to be the main clinical manifestation. This can be explained by the infections that are common in tropical areas [5].
72% of our patients had hemoglobin levels between 6 and 10 g/dl. This level is slightly higher in a study in Belgium [12]. Our results are identical to those reported in the literature and could be explained by the chronic hemolytic anemia suffered by sickle cell patients.
The average length of hospitalization was 5.28 days with extremes of 2 and 10 days. The most commonly used class of analgesics was Tier I and Tier II with a small proportion. Tier III analgesics have not been used in our series because of their official unavailability in our country. 96% of our patients received a transfusion, which could be explained by the fact that the majority of our patients were decompensating for their anemia. The evolution was favorable in 96% of the cases, however we noted one case of death, i.e. 4%. In this work, Hounsa T attributed 4 deaths to ATS and anaemia [12]

Conclusion
ATS (Acute Chest Syndrome) is a serious complication of sickle cell disease. It is one of the most common complications among sickle cell patients in the Pediatrics Department of Donka National Hospital. Community screening would be an effective way to prevent or reduce complications related to sickle cell disease, especially acute chest syndrome.