# Sickle Cell Crisis

Sickle cell crisis requires rapid recognition of vaso-occlusive pain while actively excluding acute chest syndrome, infection, stroke, and other time-sensitive complications. Care is strongest when acute analgesia, complication-directed evaluation, and longitudinal disease-modifying or curative options are coordinated with a sickle cell specialist.

**Clinical question:** How should clinicians evaluate and manage acute sickle cell crisis while identifying complications requiring urgent escalation?

Updated: 2026-08-21T00:44:00.404339+00:00

## What matters in practice
- Treat an acute pain presentation as vaso-occlusive crisis only after actively evaluating for concurrent or alternative complications, particularly acute chest syndrome, infection, and acute neurologic events. [11][18]
- Acute chest syndrome may arise during hospitalization for vaso-occlusive crisis and is associated with substantial adult critical-care burden; new respiratory symptoms, fever, chest pain, or pulmonary infiltrates warrant escalation. [11]
- Acute and chronic sickle cell pain management is evidence-informed but constrained by limited disease-specific research; ASH emphasizes interdisciplinary management and individualized decisions. [15]
- Filgrastim products can precipitate severe, sometimes fatal sickle cell crises; discontinue if crisis occurs and use only with careful risk assessment. [1]
- Hematopoietic stem cell transplantation is currently the only established curative therapy, but referral decisions require individualized assessment of complications, donor options, and transplant risk. [17]

## Identify crisis phenotype and threats that change disposition

Pain may be the presenting syndrome, but it does not exclude concurrent organ-threatening disease.

Sickle cell crisis is best approached as an acute syndrome in a patient with sickle cell disease rather than as a single diagnosis. Vaso-occlusive pain is common, but acute care evaluation must account for acute chest syndrome, infection, acute neurologic events, and other complications that require disease-specific escalation or transfer. ASH-related implementation guidance emphasizes timely emergency evaluation for acute stroke, pain, and fever, with continuity of specialty care and prearranged transfer pathways when needed. [18]

Acute chest syndrome is a high-priority diagnostic concern because it is frequent and serious in adults with sickle cell disease, accounts for a large share of ICU admissions, and may develop after admission for vaso-occlusive crisis. Reported contributors include lower respiratory tract infection, hypoventilation or atelectasis, bone-infarct-associated fat embolism, and in situ pulmonary thrombosis. [11]
- Escalate evaluation for chest pain, fever, dyspnea, hypoxemia, respiratory distress, or new pulmonary findings; these features are compatible with acute chest syndrome and should not be attributed to pain alone. [11]
- Escalate urgently for focal neurologic symptoms or suspected stroke; acute neurologic events are specifically identified as conditions needing timely emergency care and specialty-facility access. [18]
- For fever or concerning systemic illness, pursue prompt evaluation rather than presuming uncomplicated vaso-occlusion. [18]
- Review recent admissions and inpatient trajectory: acute chest syndrome has been reported to develop in 10% to 20% of patients hospitalized for vaso-occlusive crisis, with a reported average onset about 2.5 days after hospitalization. [11]

*Clinical features that should redirect evaluation beyond uncomplicated vaso-occlusive pain. [11][18]*

| Finding | Clinical implication | Immediate next priority |
| --- | --- | --- |
| Fever, chest pain, dyspnea, respiratory distress, or pulmonary infiltrate | Evaluate for acute chest syndrome, which may have infectious and noninfectious contributors. [11] | Escalate respiratory and infectious evaluation; involve hematology and acute-care teams as appropriate. [11][18] |
| Focal neurologic deficit or acute neurologic concern | Acute stroke is a time-sensitive sickle cell complication. [18] | Urgent emergency and specialty evaluation; ensure access to an appropriate facility. [18] |
| Pain with fever or systemic deterioration | Do not assume pain is isolated vaso-occlusion. [18] | Prompt acute medical evaluation and reassessment for complication-directed care. [18] |
| New respiratory symptoms after admission for pain | Acute chest syndrome can emerge during vaso-occlusive-crisis hospitalization. [11] | Repeat clinical assessment and evaluate for pulmonary complications. [11] |

## Use individualized, interdisciplinary acute pain care

Analgesic decisions should be individualized and integrated with reassessment for evolving complications.

ASH’s 2020 guideline addresses acute and chronic pain in children and adults with sickle cell disease and characterizes optimal care as interdisciplinary. The guideline also notes that limited sickle cell disease pain research and biologic differences between acute and chronic pain complicate targeted treatment decisions. [15]

In emergency and inpatient settings, operational readiness matters. The ACEP Emergency Department Sickle Cell Care Coalition was formed to improve emergency care for this population, reflecting persistent care gaps and patient-reported poor ED experiences. [22] Use a patient-specific acute-care plan when available, including the established analgesic regimen, prior effective agents, opioid tolerance, chronic analgesic exposure, disease complications, and specialist contact information.
- Assess pain severity and function while simultaneously screening for fever, hypoxemia, respiratory symptoms, chest pain, neurologic symptoms, and other features that may indicate a non-pain crisis phenotype. [11][18]
- Reassess serially during treatment; respiratory or systemic changes after an initially pain-predominant presentation should trigger renewed evaluation for acute chest syndrome or infection. [11]
- Avoid using population-level opioid-prescribing policy as a reason to withhold clinically appropriate therapy for acute or chronic sickle cell pain; ACEP reports that CDC clarification recognized that guidance should not deny indicated opioid therapy for conditions including sickle cell disease. [23]
- Arrange follow-up with a sickle cell specialist after acute care, particularly after recurrent ED use, admission, escalating analgesic requirements, or a new organ complication. Multidisciplinary care is central to optimizing outcomes. [20]

### What the available sources do not support

The supplied sources do not provide a current, extractable U.S. protocol with medication-specific opioid, nonopioid analgesic, fluid, transfusion, antibiotic, or oxygen dosing for vaso-occlusive crisis. Do not infer doses or transfusion thresholds from this review; use an institution-specific sickle cell pathway, the patient’s individualized care plan, and contemporaneous specialty guidance.

*Acute pain-care principles supported by the available sources. [15][18][22][23]*

| Care element | Decision value |
| --- | --- |
| Individualized pain plan | Supports continuity across emergency, inpatient, primary care, and hematology settings. [20][22] |
| Interdisciplinary management | ASH identifies interdisciplinary care as important because acute and chronic sickle cell pain are clinically and biologically complex. [15] |
| Serial reassessment | Helps detect acute chest syndrome or other complications that may evolve during an apparent pain crisis. [11] |
| Equitable access to analgesia | ACEP highlights concerns that opioid-policy implementation can create barriers for patients with sickle cell disease. [23] |

## Recognize acute chest syndrome early

Pulmonary deterioration is the key evolution to detect during a pain admission.

Acute chest syndrome is clinically characterized by chest symptoms or signs such as chest pain, fever, or dyspnea together with new pulmonary abnormalities; the referenced adult study describes rapid clinical progression and identifies acute respiratory failure by respiratory rate above 30 breaths/min, increased work of breathing, or labored breathing. [11] Because the syndrome has multiple potential mechanisms, diagnostic evaluation should not focus solely on bacterial infection.

The available evidence describes a mixed pathophysiology that includes lower respiratory tract infection, hypoventilation and atelectasis, fat embolism related to bone infarction, and pulmonary thrombosis. [11] This breadth is clinically consequential: an unrevealing initial microbiologic evaluation does not eliminate acute chest syndrome when the clinical and radiographic syndrome is present.
- Obtain and reassess chest imaging when respiratory symptoms, fever, chest pain, hypoxemia, or examination findings emerge during a vaso-occlusive episode. [11]
- Consider respiratory microbiologic testing in an appropriate clinical context; the cited study used conventional microbiology plus respiratory multiplex PCR to investigate infectious etiologies. [11]
- Escalate level of care for respiratory failure features, including respiratory rate above 30 breaths/min, increased work of breathing, or labored breathing. [11]
- Coordinate management with hematology and critical care when respiratory status deteriorates or acute chest syndrome is suspected. [11][18]

*Acute chest syndrome: features and etiologic framework from an adult cohort study. [11]*

| Domain | Evidence-supported point | Clinical consequence |
| --- | --- | --- |
| Timing | Reported in 10% to 20% of patients hospitalized for vaso-occlusive crisis, with reported onset about 2.5 days after admission. [11] | Continue respiratory surveillance after an initially uncomplicated pain presentation. [11] |
| Clinical presentation | Chest pain, fever, and dyspnea are described clinical features. [11] | Prompt pulmonary evaluation rather than attribution to pain alone. [11] |
| Potential causes | Infection, atelectasis or hypoventilation, fat embolism, and pulmonary thrombosis may contribute. [11] | Use a broad differential and reassess when clinical status changes. [11] |
| Severity marker | Acute respiratory failure was defined by respiratory rate above 30 breaths/min, increased work of breathing, or labored breathing. [11] | Urgent escalation and monitoring are warranted. [11] |

## Avoid pharmacologic triggers and unsupported off-label extrapolation

Some drugs pose disease-specific risks in sickle cell disease.

Filgrastim products carry a specific warning for severe and sometimes fatal sickle cell crises in patients with sickle cell disorders. The RELEUKO prescribing information directs discontinuation if a sickle cell crisis occurs. Patients who report left upper abdominal or shoulder pain should also be evaluated for splenic enlargement or rupture, and patients with fever plus pulmonary infiltrates or respiratory distress should be evaluated for ARDS. [1]

Sildenafil labeling warns about vaso-occlusive crisis in patients with pulmonary hypertension secondary to sickle cell disease, and the available label states that safety and effectiveness for pulmonary arterial hypertension secondary to sickle cell anemia have not been established. [3][5] Do not interpret sildenafil’s approval for other pulmonary hypertension populations as evidence supporting use in sickle cell-associated pulmonary hypertension.
- If prescribing a filgrastim product to a patient with a sickle cell disorder, discuss crisis risk and monitor for pain or respiratory symptoms; discontinue if crisis occurs. [1]
- With filgrastim exposure, evaluate left upper abdominal or shoulder pain for splenic complications and fever with infiltrates or respiratory distress for ARDS. [1]
- Sildenafil for pulmonary hypertension secondary to sickle cell anemia lacks established safety and effectiveness in the available labeling. [5]
- The supplied sources do not establish a disease-modifying pharmacotherapy regimen or dose for prevention of recurrent vaso-occlusive crises; specialist-directed therapy selection is required.

*Medication-specific considerations in sickle cell disease. [1][3][5]*

| Agent or class | Key concern | Action |
| --- | --- | --- |
| Filgrastim products | Severe and sometimes fatal sickle cell crises have occurred. [1] | Discontinue if sickle cell crisis occurs; evaluate concerning splenic or respiratory symptoms. [1] |
| Sildenafil | Labeling includes vaso-occlusive-crisis warning in pulmonary hypertension secondary to sickle cell disease. [3] | Do not assume efficacy or safety for pulmonary arterial hypertension secondary to sickle cell anemia; it has not been established in the available label. [5] |

## Convert recurrent crisis into a longitudinal management decision

Recurrent acute-care use should prompt reassessment of preventive and potentially curative strategies.

Sickle cell disease produces lifelong acute and chronic pain, end-organ injury, chronic anemia, and reduced survival. A U.S. primary care review emphasizes that optimal outcomes require a partnership among patients, primary care clinicians, hematologists, and other caregivers. [20] Following a crisis, identify whether the patient has an established hematology team, a documented emergency plan, reliable follow-up, and barriers to medication access or specialist care.

For patients with severe complications or an appropriate risk-benefit profile, referral for curative-therapy assessment may be appropriate. ASH’s 2021 guideline states that hematopoietic stem cell transplantation is currently the only curative therapy for sickle cell disease, while also underscoring the need for evidence-based, individualized decisions. [17] The supplied sources do not provide sufficient detail to specify transplant candidacy criteria, donor hierarchy, conditioning approach, or gene-therapy eligibility.
- Ensure a written acute-care plan is available across ED, inpatient, primary care, and hematology settings. [18][20][22]
- Address preventive care and screening in longitudinal follow-up; a 2025 National Alliance of Sickle Cell Centers consensus process included preventive care, screening assessments, and treatment options across the lifespan. [8]
- Refer to a sickle cell/transplant center when disease burden and patient goals justify discussion of hematopoietic stem cell transplantation. [17]
- Do not use hemoglobin haplotype alone to personalize treatment or prognosis; available review evidence states that haplotype has limited immediate clinical utility because severity and hydroxyurea response vary substantially. [14]

*Post-crisis actions that support safer longitudinal care. [8][17][18][20]*

| Post-acute task | Reason |
| --- | --- |
| Document individualized emergency plan | Supports timely acute pain, fever, and neurologic-event care across settings. [18][22] |
| Reconnect with hematology and primary care | Multidisciplinary care is emphasized for optimizing outcomes in a chronic, multisystem disease. [20] |
| Review preventive care and screening | National consensus standards include preventive care and screening assessments for people living with sickle cell disease. [8] |
| Consider curative-therapy referral | Hematopoietic stem cell transplantation is the only currently established curative therapy. [17] |

## Common questions

### Can vaso-occlusive crisis be assumed when pain is typical for the patient?

No. Typical pain may coexist with acute chest syndrome, infection, or acute neurologic disease. New fever, chest symptoms, dyspnea, hypoxemia, pulmonary findings, or focal deficits should redirect evaluation and escalation. [11][18]

### When should acute chest syndrome be suspected during a pain admission?

Suspect it with new chest pain, fever, dyspnea, respiratory distress, or pulmonary infiltrates. It can develop after admission for vaso-occlusive crisis, so repeated respiratory assessment is clinically important. [11]

### Should filgrastim be used cautiously in sickle cell disease?

Yes. Filgrastim labeling reports severe and sometimes fatal sickle cell crises; discontinue the product if crisis occurs and evaluate associated splenic and respiratory warning symptoms. [1]

### Is sildenafil established therapy for pulmonary hypertension secondary to sickle cell anemia?

No. The available sildenafil labeling states that safety and effectiveness for pulmonary arterial hypertension secondary to sickle cell anemia have not been established and includes a vaso-occlusive-crisis warning for this population. [3][5]

### When should curative therapy be discussed after recurrent crises?

Discuss referral to a sickle cell/transplant center when complications, recurrent acute-care burden, and patient goals warrant individualized evaluation. Hematopoietic stem cell transplantation is the only currently established curative therapy. [17]

## References
1. These highlights do not include all the information needed to use RELEUKO safely and effectively. See full prescribing information for RELEUKO.
         
      RELEUKO® (filgrastim-ayow) injection, for subcutaneous or intravenous use.Initial U.S. Approval: 2022
      
      
	 RELEUKO (filgrastim-ayow) is biosimilar* to NEUPOGEN® (filgrastim) — dailymed.nlm.nih.gov — https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=74e1ec6e-1630-4654-895c-2bd355f939e7&type=display
2. SILDENAFIL — dailymed.nlm.nih.gov — https://dailymed.nlm.nih.gov/dailymed/getFile.cfm?setid=761f9606-2583-439a-a29e-736008340a9e&type=pdf
3. These highlights do not include all the information needed to use SILDENAFIL TABLETS safely and effectively. See full prescribing information for SILDENAFIL TABLETS.
 
SILDENAFIL tablets, for oral use
 
Initial U.S. Approval: 1998 — dailymed.nlm.nih.gov — https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=e4f41e9e-d508-4f91-8677-8a19b07139de&type=display
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## Editorial note

Prepared from cited clinical literature using Astra's research workflow. Verify recommendations against current guidance and patient-specific factors.