Sickle Cell Crisis

Key considerations: Acute Chest Syndrome (ACS) — most common cause of death in sickle cell disease, Stroke — ischemic or hemorrhagic, Splenic sequestration crisis — life-threatening in children

Cannot miss

Acute Chest Syndrome (ACS) — most common cause of death in sickle cell disease
Stroke — ischemic or hemorrhagic
Splenic sequestration crisis — life-threatening in children
Aplastic crisis — parvovirus B19 infection causing severe anemia
Sepsis — functional asplenia makes patients highly susceptible
Priapism — urological emergency if >4 hours
Avascular necrosis of femoral head
Pulmonary hypertension

Red flags

Fever >38.5°C — functional asplenia means sepsis until proven otherwise
Chest pain, dyspnea, or new pulmonary infiltrate — Acute Chest Syndrome
Neurological symptoms — headache, weakness, vision changes, seizure (stroke)
Severe anemia below baseline — splenic sequestration or aplastic crisis
Priapism lasting >4 hours
Acute abdominal pain with splenomegaly — splenic sequestration
Oxygen saturation below patient baseline
Pain crisis not responding to opioid therapy
Rapidly enlarging spleen in a child

Workup

history: Baseline hemoglobin — critical to know patient baseline for comparison; Sickle cell genotype — HbSS (most severe), HbSC, HbS-beta thalassemia; Home medication regimen — hydroxyurea, prophylactic penicillin, folic acid; Vaccination history — Pneumococcal, Meningococcal, Haemophilus influenzae; Prior hospitalizations — frequency and type of crises; Pain location and character — bone pain typical in VOC, chest pain raises ACS; Triggers — dehydration, cold exposure, altitude, infection, stress, alcohol; Last transfusion and any transfusion reactions; Fever — when started, how high; Respiratory symptoms — cough, dyspnea, pleuritic chest pain; Neurological symptoms — headache, weakness, vision changes; exam: Vital signs — temperature (sepsis), SpO2 (compare to patient baseline); Pain assessment — location, severity (0–10), quality; Respiratory exam — breath sounds, work of breathing; Abdominal exam — spleen size (rapidly enlarging = sequestration); Neurological exam — focal deficits suggesting stroke; Skin — jaundice (hemolysis), pallor (severe anemia); Genitourinary — priapism assessment in males; Joints — avascular necrosis assessment; Signs of infection — meningismus, wound, urinary symptoms; labs: CBC with differential and reticulocyte count — compare to patient baseline Hgb; Reticulocyte count — low in aplastic crisis (parvovirus), elevated in hemolytic crisis; Type and screen — in case transfusion needed; Comprehensive metabolic panel — renal and hepatic function; LDH and bilirubin — markers of hemolysis; Blood cultures × 2 — if febrile; Urinalysis and urine culture — common infection source; Parvovirus B19 IgM — if aplastic crisis suspected (low retic + severe anemia); D-dimer and troponin — if ACS or PE suspected; HbS percentage if on exchange transfusion program; imaging: CXR — mandatory if any respiratory symptoms or fever (ACS diagnosis); CT head without contrast — if stroke suspected (then MRI/MRA for definitive); Abdominal ultrasound — if splenic sequestration suspected; X-ray of painful bones — avascular necrosis, bone infarct; CT chest — if ACS not clear on CXR; bedside: SpO2 — compare to patient documented baseline (many have baseline 94–96%); ECG — if chest pain present; POCUS — splenic size, pleural effusion, pericardial effusion

Management

immediate: Supplemental oxygen if SpO2 below baseline or <95%; IV access and aggressive IV fluid hydration — D5½NS at 1–1.5× maintenance (avoid hypotonic fluids); Pain management — do not delay analgesia; Blood cultures and antibiotics if febrile — treat as sepsis until proven otherwise; general: Pain management is the priority in vaso-occlusive crisis (VOC); NSAIDs first line for mild-moderate pain — ketorolac 15–30mg IV or ibuprofen PO; Opioids for moderate-severe pain — IV morphine or hydromorphone, titrate to effect; Patient-controlled analgesia (PCA) for consistent pain control during admission; Avoid meperidine (Demerol) — metabolite normeperidine causes seizures in sickle cell; Incentive spirometry every 2 hours while awake — prevents atelectasis and ACS; Warm compresses to painful areas; Hematology consult for all admitted patients; specific: diagnosis: Acute Chest Syndrome; steps: Supplemental oxygen to maintain SpO2 >95% or at baseline; Incentive spirometry every 2 hours; Empiric antibiotics — ceftriaxone + azithromycin (covers typical and atypical organisms); Simple transfusion if Hgb >1g/dL below baseline — target Hgb 10 g/dL; Exchange transfusion if severe ACS — reduce HbS% to <30%; Bronchodilators if bronchospasm present; Avoid aggressive IV fluids — risk of fluid overload with pulmonary involvement; ICU admission if severe — may require mechanical ventilation; diagnosis: Fever and Suspected Sepsis; steps: Blood cultures × 2 immediately; Ceftriaxone 50mg/kg IV (max 2g) within 1 hour of presentation; Add vancomycin if toxic appearing or MRSA risk; Low threshold for LP if meningitis suspected; Admit all febrile sickle cell patients — functional asplenia makes them extremely vulnerable; Avoid observation at home for fever in sickle cell disease; diagnosis: Splenic Sequestration (Pediatric); steps: Rapidly enlarging spleen + acute anemia + hypovolemia = emergency; Immediate IV fluid resuscitation; Emergent transfusion — pRBC to stabilize hemodynamics; Do not overtransfuse — splenic blood may re-enter circulation causing polycythemia; Pediatric hematology consult emergently; Splenectomy considered after recurrent episodes; diagnosis: Stroke; steps: Emergency exchange transfusion — reduce HbS% to <30% as quickly as possible; Do not give tPA — exchange transfusion is the treatment; CT head to rule out hemorrhage first; MRI/MRA for definitive stroke evaluation; Neurology and hematology consult emergently; Maintain adequate hydration — avoid dehydration; diagnosis: Aplastic Crisis; steps: Caused by parvovirus B19 — suppresses erythropoiesis; Low reticulocyte count with severe anemia is the hallmark; Transfusion if symptomatic or Hgb critically low; Contact precautions — parvovirus contagious; Spontaneously resolves in 1–2 weeks; Parvovirus B19 IgM confirms diagnosis; diagnosis: Priapism; steps: If >4 hours — urological emergency; IV hydration and analgesia first; Aspiration of corpora cavernosa + epinephrine injection (urology); Exchange transfusion if unresponsive to local treatment; Surgical shunting if all else fails; Do not delay urology consult beyond 4 hours — permanent erectile dysfunction risk

Disposition

admit: All febrile sickle cell patients — no safe discharge with fever; Acute Chest Syndrome — all require admission, ICU if severe; Stroke; Splenic sequestration; Aplastic crisis; Priapism not resolved with initial treatment; Pain crisis not controlled with oral medications; Significant drop in hemoglobin below baseline; discharge: Uncomplicated VOC with pain controlled on oral medications; Afebrile with no evidence of ACS or other complications; Hemoglobin at or near patient baseline; Reliable follow-up with hematology; Patient and family understand return precautions; consults: Hematology — all admitted sickle cell patients; Urology — priapism >4 hours; Neurology — stroke or neurological symptoms; Pulmonology — recurrent ACS; Ophthalmology — retinal involvement

Clinical pearls

Every febrile sickle cell patient must be admitted — functional asplenia from repeated splenic infarction means even encapsulated organisms (Strep pneumoniae, H. influenzae, N. meningitidis) can cause rapidly fatal sepsis.
Acute Chest Syndrome is the leading cause of death in sickle cell disease. It can start as a VOC and evolve — always order CXR in admitted patients and reassess daily.
Never use meperidine (Demerol) in sickle cell patients — its metabolite normeperidine accumulates and causes seizures, especially in renal impairment which is common in SCD.
Stroke in sickle cell is treated with emergency exchange transfusion, NOT tPA. The goal is to rapidly reduce the percentage of HbS in circulation.
Incentive spirometry every 2 hours while awake is not optional — it is a critical intervention that reduces the development of ACS in admitted patients.

Source and review

NHLBI Sickle Cell Disease Guidelines 2014; ASH Sickle Cell Guidelines 2020; Tintinalli Emergency Medicine 9th ed.. Last reviewed: 2024-11-01