Managing Pain in Sickle Cell Vaso-Occlusive Crises

By |July 25th, 2025|Hematology| Overview and Epidemiology Vaso-occlusive crises, or VOCs, are the most frequent cause of emergency visits and hospitalizations for individuals with sickle cell disease (SCD). They are responsible for more than 70 percent of ED visits among children with SCD and account for substantial healthcare utilization and missed school days. Most children with homozygous HbSS will experience their first painful episode before the age of 6. Recurrent VOCs are associated with higher risks of chronic pain, opioid use, and diminished quality of life. Why Do VOCs Happen? Sickle cell disease is caused by a point mutation in the beta-globin gene, leading to hemoglobin S. Under stress—such as infection, dehydration, or even cold exposure—red blood cells polymerize, sickle, and become rigid. These sickled cells obstruct capillaries and small vessels, leading to local tissue ischemia, inflammation, and pain. It’s not just about the blockage—the inflammatory cascade, endothelial damage, and cytokine release all contribute to the pain experience. What Does the Pain Feel Like? Ask kids and teens with sickle cell disease, and they’ll describe their pain as deep, throbbing, stabbing, or aching. It often feels bone-deep and can be relentless and exhausting. Many say it’s unlike any other pain—they may compare it to being “hit with a bat,” “bone being crushed,” or “something stuck inside my limbs trying to get out.” Common sites include: Long bones (femur, humerus) Lower back Chest (look out for acute chest syndrome) Abdomen Hands and feet (especially in younger children—think dactylitis) Clinical Presentation History Ask about typical pain patterns and how this episode compares to prior ones. Look for triggers: dehydration, weather changes, infection, stress. Document home medications, including opioid tolerance and response to prior ED treatments. Physical Exam Often nonspecific. Localized tenderness, guarding. May have fever if infection is present (but fever is not diagnostic of VOC). Look for signs of acute chest syndrome: tachypnea, hypoxia, chest pain. Vitals May show tachycardia from pain or dehydration. Febrile patients should be evaluated for sepsis or osteomyelitis. Pain scales Use age-appropriate tools: FLACC, Wong-Baker FACES, or numerical rating scales. Management: Treat Early, Treat Effectively Pain Medications Start early. Do not delay for labs. Aim for analgesia within 30–60 minutes of arrival. Mild pain (rare in ED): Acetaminophen or NSAIDs (e.g., ibuprofen, ketorolac). Moderate to severe pain: Opioids are first-line. Morphine IV: 0.1 mg/kg (max 10 mg) every 15–30 minutes as needed; consider PCA in admitted patients. Hydromorphone IV: 0.015 mg/kg if morphine does not work or if the patient has used it effectively in the past. Intranasal fentanyl: 1.5–2 mcg/kg as a bridge while waiting for IV access. Avoid codeine and meperidine due to poor efficacy and neurotoxicity risks. Reassess every 15–30 minutes until pain is controlled, then space doses out. Adjunctive Therapies Hydration: Lactated Ringer’s is associated with shorter hospital stays and lower readmission rates than normal saline. Avoid fluid overload; maintain euvolemia. Heat packs for local comfort. Distraction techniques, Child Life, music, games, screens. Anxiolytics may be considered for severe distress but use cautiously. Labs and Imaging Labs are not always needed if the child looks well and has an uncomplicated VOC. Follow local protocols. Consider: CBC and reticulocyte count: A low retic suggests aplastic crisis (often parvovirus B19). A high retic is appropriate in VOC, showing marrow response. Compare hemoglobin to baseline. BMP for renal function. LFTs or lipase if right upper quadrant pain. Chest x-ray if chest symptoms present. Blood cultures if febrile. Oxygen Only indicated if the patient is hypoxic. Transfusion Routine transfusion is not indicated for uncomplicated VOC. May be used in complications such as acute chest syndrome, stroke, or symptomatic anemia. Disposition: Discharge vs. Admission Discharge if: Pain is improved and manageable on oral medications. Tolerating oral intake. No concern for complications. Reliable follow-up and support available. Admit if: Persistent severe pain despite multiple IV doses. Need for frequent parenteral opioids. Acute chest syndrome, sepsis, or other complications. Poor outpatient support or unreliable follow-up. Complications to Watch For Acute chest syndrome: Chest pain, hypoxia, new infiltrate on chest x-ray. Splenic sequestration: Rapid hemoglobin drop, splenomegaly, signs of shock. Stroke: New neurologic deficits. Sepsis: Fever, tachycardia, especially in asplenic patients. Avascular necrosis: Recurrent or chronic hip or shoulder pain. Chronic pain: Increasing in frequency in adolescents and young adults. Prevention Hydroxyurea is the cornerstone of prevention. It increases fetal hemoglobin and reduces the frequency and severity of pain crises. It can be started as early as 9 months of age in children with HbSS or Sβ⁰-thalassemia. Other preventive strategies include: Staying hydrated. Avoiding extreme cold exposure. Keeping up with vaccines and penicillin prophylaxis. Addressing mental health and social stressors. Take-Home Points Treat pain promptly and aggressively. Do not wait on labs. Use IV opioids for moderate to severe pain and reassess often. Lactated Ringer’s may be preferred for IV hydration, but avoid overload. Labs and imaging should follow clinical appearance and local protocols. Reticulocyte count and hemoglobin trends are key. Disposition should be based on pain control, potential complications, and social support. Prevention matters—hydroxyurea and primary care follow-up reduce crises and admissions. References Kavanagh PL, Fasipe TA, Wun T. Sickle cell disease: a review. JAMA. 2022;328(1):57-68. doi:10.1001/jama.2022.10233 Yates AM, Aygun B, Nuss R, Rogers ZR. Health supervision for children and adolescents with sickle cell disease: clinical report. Pediatrics. 2024;154(2):e2024066842. doi:10.1542/peds.2024-066842 Bender MA, Carlberg K. Sickle Cell Disease. In: Adam MP, Everman DB, Mirzaa GM, et al, eds. GeneReviews®. University of Washington, Seattle; 1993–2024. Updated February 13, 2025. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1377/ Brandow AM, Carroll CP, Creary S, et al. American Society of Hematology 2020 guidelines for sickle cell disease: management of acute and chronic pain. Blood Adv. 2020;4(12):2656-2701. doi:10.1182/bloodadvances.2020001851 Brandow AM, Carroll CP, Creary SE. Acute vaso-occlusive pain management in sickle cell disease. In: Hoffman R, Benz EJ, Silberstein LE, Heslop HE, Weitz JI, Anastasi J, eds. UpToDate. UpToDate; 2024. Accessed July 2025. https://www.uptodate.com Glassberg JA, Strouse JJ. Evaluation of acute pain in sickle cell disease. In: Hoffman R, Benz EJ, Silberstein LE, Heslop HE, Weitz JI, Anastasi J, eds. UpToDate. UpToDate; 2024. Accessed July 2025. https://www.uptodate.com DeBaun MR, Quinn CT. Overview of the clinical manifestations of sickle cell disease. In: Hoffman R, Benz EJ, Silberstein LE, Heslop HE, Weitz JI, Anastasi J, eds. UpToDate. UpToDate; 2024. Accessed July 2025. https://www.uptodate.com McCavit TL. Overview of preventive outpatient care in sickle cell disease. In: Hoffman R, Benz EJ, Silberstein LE, Heslop HE, Weitz JI, Anastasi J, eds. UpToDate. UpToDate; 2024. Accessed July 2025. https://www.uptodate.com About the Author: Brad Sobolewski, MD, MEd Brad Sobolewski, MD, MEd is a Professor of Pediatric Emergency Medicine and the Associate Director of Physician and Team-Based Education at Cincinnati Children's Hospital Medical Center. He is on Twitter/X @PEMTweets, on Instagram @BradSobolewski, authors the Pediatric Emergency Medicine site PEMBlog and is the host and creator of PEM Currents: The Pediatric Emergency Medicine Podcast. All views are strictly my own and not official medical advice. Related Posts