1. Sickle Cell Emergencies
Mimi Boren, MD and Kristin Wessel, MD
Comer Children’s Hospital

2. Pretest
1.) What important preventative measure should be ordered for all patients who are in the hospital with VOC in order to prevent the development of ACS?
a.) place on O2 to maintain sats >95%
b.) elevate head of bed
c.) incentive spirometry q 2
d.) lower extremity compression stockings
2.) Which of the following is a potential long term side effect of priapism?
a.) daily penile pain
b.) erectile dysfunction
c.) urinary frequency
d.) discoloration of skin on penis

3. 3.) Why should all parents of SCD patients be taught shortly after birth to palpate their child’s spleen?
a.) to recognize when his or her spleen is auto-infarcted
b.) to recognize when his or her spleen is enlarging and he or she may be at risk for splenic sequestration
c.) to recognize when he or she has a sign of malignancy
d.) to recognize when their child is at risk for invasive bacteremia from an encapsulated organism
4.) Which 2 imaging studies should you order for a patient with an acute stroke?
a.) MRI brain and CT angiogram head
b.) Stat head CT and CT angiogram head and neck
c.) MRI head and neck and echocardiogram
d.) Chest x-ray and head CT

4. 5.) When are patients with SCD most at risk for splenic sequestration?
a.) Within the first 10 years of life
b.) before age 2
c.) between ages 2 and 12
d.) When they present with dactylitis

5. Fever
Reduced or absent splenic function predisposes patients with SCA to severe bacterial infection, particularly with encapsulated organisms
High risk of septicemia and meningitis secondary to Streptococcus pneumoniae
Increased risk of gram-negative enteric infections involving urinary tract, hepatobiliary system or bones
In SCD patient with fever, consider:
Acute chest syndrome
Bacteremia/meningitis
Osteomyelitis (Staphylococcus aureus or Salmonella)
Aplastic crisis

6. Management of fever in SCD
For temperature 38.5 or higher, obtain the following labs: CBC/diff, reticulocyte count, blood culture and urine culture if UTI suspected
Promptly administer parenteral antibiotic with coverage for Streptococcus pneumoniae
Well-appearing children may be managed as outpatients with close follow-up and oral antibiotics
Children who are ill-appearing or with temperature to or higher should be admitted for parenteral antibiotics
Obtain CXR for patients with cough, tachypnea, hypoxia, or adventitious lung sounds
Consider osteomyelitis in setting of bony tenderness, erythema or swelling

7. Aplastic crisis
Temporary cessation of red cell production causing acute drop in Hgb
Associated with Parvovirus B19, which infects red cell precursors in the bone marrow
Because of reduced RBC survival time in SCD, these patients are especially vulnerable to bone marrow suppression
Clinical presentation: lethargy, fever, pallor, tachycardia, can present in heart failure
Labs: Hgb typically 3-6 g/dL, reticulocyte count reduced or zero
Management: pRBC transfusion to restore Hgb to safe level, isolation, supportive care until reticulocyte count recovers

8. Vaso-Occlusive Crisis
Acute severe pain associated with sickling and occlusion of blood vessels
Most common complication of sickle cell disease
May present as early as 6 months of age, often with dactylitis
Most common sites of pain are extremities, chest and back
More frequent in HbSS and HbSβ0-thalassemia
Individuals with >3 hospitalizations for VOC in a year are at increased risk for early death

9. Vaso-Occlusive Crisis
Pain Management
Administer analgesics as early as possible (within 60 minutes of registration in ED, or within 30 minutes of triage)
Offer intranasal fentanyl while establishing IV access; can also administer parenteral opioids SubQ if having difficulty with IV access
Ask patient or review chart to determine initial pain management that has worked in the past
Can calculate opioid dose by calculating total short-acting dose that patient is taking at home
Parenteral opioids should be administered in cases of severe pain
Reassess pain every minutes, consider escalation of analgesic dose by 25 percent if pain remains uncontrolled
Administer ketorolac or other NSAID in conjunction with opioids
Administer fluid bolus in ED, start maintenance fluids if admitted
If pain not controlled after 3 doses of parenteral opioids, plan for admission
If patient admitted for VOC, PCA should be started for optimal pain control

10. Vaso-Occlusive Crisis
Supportive care
Incentive spirometry and early ambulation important for prevention of atelectasis and acute chest syndrome
Supplemental oxygen for SpO2 < 95%
Oral antihistamines for opioid-associated itching
Close monitoring of respiratory status and over- sedation; make sure naloxone ordered with PCA
Heat packs or lidocaine patches for localized pain
Keep in mind other etiologies of pain (pneumonia, acute cholecystitis)

11. Acute Chest Syndrome: Definition
Clinical diagnosis requiring BOTH of the following criteria
New pulmonary infiltrate on chest radiograph
One or more of the following:
Chest pain
Temperature >38.5 C
Tachypnea, wheezing, cough or retractions
Hypoxemia relative to baseline measurements

12. Acute Chest Syndrome: Epidemiology
Major cause of morbidity and mortality in SCD
2nd most common cause of hospitalization in SCD (after vasoocclusive pain crisis), and most common cause of death
Occurs more commonly in winter months
Peak incidence in children 2-4 years of age

13. Acute Chest Syndrome: Pathogenesis
Most common cause of acute chest syndrome is infection (viral or bacterial), but can also result from bone marrow embolism in lungs from necrotic bone marrow (think pain crisis in long bones), intrapulmonary aggregates of sickled cells, or pulmonary edema
Any of the above can lead to V/Q mismatching, alveolar hypoxia and decreased in PaO2 in the pulmonary vasculature, leading to sickling of cells
Endothelial dysfunction in the pulmonary vasculature

14. Risk Factors Recent surgery (post-op atelectasis can lead to ACS)
Approximately 50% develop ACS during hospitalization for pain crisis, so watch out for this when patient in house for pain crisis and have every patient who has VOC do incentive spirometry q 2 to avoid development of atelectasis
Use of opioids may lead to hypoventilation
VOC localized to rib, spine, or abdomen in particular contributes to hypoventilation
Recent surgery (post-op atelectasis can lead to ACS)
Asthma
Remember: if patient comes in with VOC pain and has shortness of breath, get a chest x-ray to rule out ACS!

15. Management of ACS
Adequate pain control to prevent hypoventilation and atelectasis (PCA if needed)
IV fluids
1x maintenance, as dehydration can lead to sickling
Excessive fluids can lead to pulmonary edema and heart failure
Daily weights to monitor fluid status
Lab evaluation:
CBC/diff, reticulocyte count, T&S
blood cultures if patient is febrile
Maintain O2 sats > 92% (with nasal cannula or BiPap if needed)
Antibiotics: a third generation cephalosporin like ceftriaxone and a macrolide like azithromycin to cover for atypical organisms (mycoplasma and chlamydia)
pRBC transfusion if indicated, consider early on in course

16. Management of ACS: Indications for transfusion
Simple transfusion
Oxygen saturation <92% in room air
Hct 10-20% below patient’s baseline, or dropping Hct during admission
Clinical or radiological progression of disease without impending respiratory failure
Exchange transfusion
Progression of illness despite simple transfusion
Severe hypoxemia
Multi-lobar disease
Previous history of ACS or severe cardiopulmonary disease
Goal is to reduce HgbS to <30%, Hgb should not exceed 10 g/dL

17. Priapism
Definition: sustained penile erection lasting more than 2 hours. 2 types: high flow (arterial, usually seen in trauma) and low flow priapism. In SCD usually have low flow priapism
Low flow priapism: sickling in venous sinusoids prevents outflow of blood, usually very painful
Can occur at any age but typically more common in SCD patients after puberty
Most often occurs during sleep
If untreated can lead to erectile dysfunction
2 types of priapism seen in SCD
Prolonged: episode lasts at least 4 hours, carries risk of permanent vascular damage and impotence
Stuttering: Shorter episodes that spontaneously resolve, can occur in clusters and precede a prolonged episode

18. Priapism Treatment IV fluids Pain control Pseudophedrine Heat packs
Dose of mg at bedtime, may give additional 30 mg dose if priapism occurs
Heat packs
If no improvement with above measures and episode lasts 4 hours, consult urology for aspiration and irrigation
Exchange transfusion has been used if episode does not resolve after aspiration
Risk of ASPEN syndrome (Association of Sickle cell disease, Priapism, Exchange transfusion and Neurologic events)

19. Splenic Sequestration
Definition: vaso-occlusion in the spleen and pooling of RBCs leads to a marked drop in Hgb by > 2 g/dL and persistent reticulocytosis
Often see thrombocytopenia as platelets become trapped in the spleen
Patient may present with hypovolemic shock and severe anemia
Patients most at risk for this before age 2, most commonly occurs between age 1-4 years as autoinfarction and involution of the spleen will typically occur by age 5
May be first clinical manifestation of SCD, can occur as early as a few months of age
All parents of patients with SCD must be taught how to palpate spleen so they can recognize when spleen is enlarging and splenic sequestration may be occurring

20. Treatment of Splenic Sequestration
Immediate resuscitation with IV fluids
Transfuse pRBCs in small aliquots every hours b/c want to avoid risk for hyperviscosity if spleen abruptly unloads “trapped” RBCs
Hgb should not be greater than 8
Goal: to make patient euvolemic
Splenectomy usually recommended after first acute sequestration episode

21. Stroke
Stroke is relatively common and devastating complication seen with SCD-incidence is 10% in patients with HgbSS
Usually occurs secondary to stenosis/occlusion of internal carotid or middle cerebral artery
May be precipitated by ACS, parvovirus infection, or other acute anemic events
Consider possible stroke if patient has severe headache, seizure, altered mental status, hemiparesis, gait disturbance, or dysphasia
For complete guidelines, see “Pediatric Acute Stoke Patient Guidelines” established by neurology and hematology teams
For patients presenting within 6 hours of suspected symptom onset, activate acute stroke page system (Dial 144)

22. Stoke (continued) Initial management:
Assess ABCs and put patient on cardiac monitor
Place head of bed flat unless contraindicated due to cardiac or resp conditions
Start maintenance IVF
Obtain the following labs: CMP, Mg, Phos, CBC, Coag panel, type and screen, Hgb electrophoresis and reticulocyte count
Maintain strict NPO
Obtain STAT head CT and CTA of head and neck
IF CT shows subarachnoid or intracerebral hemorrhage>>>consult neurosurgery
Discuss blood pressure management with neurology team

23. References
Yawn, BP, Buchanan, GR., Afenvi-Annan, AN, et al Management of Sickle Cell Disease: Summary of Evidence-Based Report by Expert Panel JAMA 2014:312
Abbas, H, Kahale M. Hosn M, Inati A. A review of Acute Chest Snydrome in Pediatric Sickle Cell Disease. Pediatric Annals ; 42,
Rogers, ZR. Priapism in sickle cell disease. Hematology/Oncology Clinics of North America. 2005; 19(5):