Understanding Acute Chest Syndrome in Sickle Cell Disease: Diagnosis and Management

Good Morning  Morning report July 23, 2012

Illness Script • Predisposing Conditions • Age, gender, preceding events (trauma, viral illness, etc), medication use, past medical history (diagnoses, surgeries, etc) • Pathophysiological Insult • What is physically happening in the body, organisms involved, etc. • Clinical Manifestations • Signs and symptoms • Labs and imaging

Semantic Qualifiers

CXR 1: LUL consolidation

CXR 2: Worsening of the LUL consolidation with development of a small pleural effusion

What Happens in SCD?** • Autosomal recessive • Chromosome 11 • Glutamine  Valine • Polymerization of HgbS on de-oxygenation • Crescent shaped RBCs • Vascular occlusion • Organ ischemia • End-organ damage

Early Diagnosis** • Can be detected at birth on the NBS • Early detection = better outcome • Decreased bacteremia/sepsis (by 84%) • PenVK started by 3 months • PCV13 at 2, 4, 6mo • PCV23 at 2 & 5yo

ACS Predisposing Conditions • Peak age 2-4 years • Winter months • Recurrence higher if first episode of ACS is before the age of 3yo • Opioid usage (PO > IV) with preceding VOC • Decreased inspiratory effort  • Areas of atelectasis  • Predisposition to development of ACS • Bacteremia (in young children) • Over-hydration during another illness

ACS Pathophysiology • Infectious (at least 30% associated with + sputum or BAL cultures) • Strep pneumo (most common in younger children) • Mycoplasma, chlamydia • Staph aureus, Hib, Salmonella, Enterobacter • Fat embolus to the lungs • Arises from micro-infarction to the bone marrow • If large, can be life threatening • Other vascular occlusions from the sickling process • COMBINATION of ABOVE

ACS Clinical Manifestations • Fever, cough, chest pain = most common • SOB, wheeze, hemoptysis, chills • Hypoxia and respiratory distress • New infiltrate on CXR • Upper lobe more common in children • Can be multi-lobar • Associated pleural effusion • Hgb decreased from baseline • Leukocytosis • + blood cultures and/or sputum or BAL cultures

2nd leading cause of admissions after VOC** More common in children but more severe in adults Acute Chest Syndrome

Acute Chest Syndrome • Definition • The radiologic appearance of new pulmonary infiltrate involving at least one complete lung segment plus one of the following • Fever >38.5 • Hypoxia • Chest pain • Signs of respiratory distress (tachypnea, wheezing, cough, retractions)

Acute Chest Syndrome • Treatment • Broad spectrum antibiotics • Cephalosporin (Rocephin) • Macrolide (Azithromycin) • +/- Vancomycin(often used here at CHNOLA) • Hydration (2/3 to 3/4 MIVF) • Oxygen (goal sats >92%) • Incentive spirometry and CPT • Bronchodilators +/- steroids • If patient has a history of asthma • Pain control

Acute Chest Syndrome • Treatment • Simple transfusion • Goal Hgb close to 10g/dL • EARLY!! • Exchange transfusion • Progressive illness despite treatment • Significant hypoxia • Multi-lobe infiltrates

Acute Chest Syndrome • Importance • About 50% of SCD patients experience at least 1 episode of ACS • Significant morbiditiy and mortality • Multiple ACS episodes may lead to • Chronic, restrictive pulmonary disease • Pulmonary HTN • Children with recurrent episodes should be evaluated with PFTs by a pediatric pulmonologist

Thanks for your attention  Noon conference: heme/Onc Emergencies Dr. velez

Understanding Acute Chest Syndrome in Sickle Cell Disease: Diagnosis and Management