Suspected osteomyelitis when plain films nondiagnostic
Marrow edema patterns
CT
CT use cases
CT head
New focal neurologic deficit
Altered mental status without explanation
CT pulmonary angiography
PE concern with hypoxia or pleuritic chest pain
CT abdomen and pelvis
Severe abdominal pain atypical for patient
Concern for appendicitis or other surgical abdomen
Ultrasound
Ultrasound applications
Lung ultrasound
B-lines or consolidation supporting acute chest syndrome or pneumonia
Lower extremity venous ultrasound
Unilateral leg swelling for DVT
RUQ ultrasound
Gallstones or cholecystitis
Testicular ultrasound
Testicular torsion mimic in groin pain presentations
Plain radiography and ECG
High-yield basic tests
Chest X-ray
Any chest symptoms
Fever without source
Baseline for evolving acute chest syndrome
ECG
Chest pain
Significant tachycardia
Disposition
Admission and higher level of care
Admission criteria
Uncontrolled pain
Persistent severe pain after ED parenteral opioid escalation
Need for PCA or continuous infusion strategy
Complication concern
Hypoxia or new oxygen requirement
New infiltrate on CXR
Fever with uncertain source
Hemodynamic instability
New neurologic symptoms
Acute kidney injury
High-risk social context
Inability to obtain medications
No safe follow-up
ICU criteria
Escalating respiratory support
High-flow oxygen requirement
Rising work of breathing
Exchange transfusion pathway activation
Suspected stroke
Severe acute chest syndrome
Discharge and observation
Discharge criteria
Pain control
Controlled on oral regimen
Ambulating or baseline mobility
Physiologic stability
SpO2 92% or higher on room air
No fever or clear outpatient plan for fever source
Complication exclusion
No chest symptoms
No neurologic symptoms
Follow-up plan
Hematology or primary care follow-up within 24-72 hours when feasible
Observation unit criteria
Intermediate pathway
Needs serial analgesia reassessment
Mild dehydration requiring monitored fluids
Treatment
Analgesia strategy
Multimodal analgesia
Opioid pathway for severe pain
Morphine IV 0.1 mg/kg
Repeat 0.05-0.1 mg/kg every 15-30 minutes to effect
Typical adult bolus 4-8 mg IV
Hydromorphone IV 0.015 mg/kg
Repeat 0.0075-0.015 mg/kg every 15-30 minutes to effect
Typical adult bolus 0.5-1 mg IV
Fentanyl IV 0.5-1 mcg/kg
Repeat every 5-10 minutes for rapid titration
Useful option with renal impairment
PCA option for admitted patients
Morphine PCA example
Demand dose 1 mg
Lockout 6-10 minutes
Basal infusion per protocol for opioid-tolerant patients
Hydromorphone PCA example
Demand dose 0.2 mg
Lockout 6-10 minutes
Basal infusion per protocol for opioid-tolerant patients
Non-opioid adjuncts
Ketorolac IV 15 mg
Every 6 hours as needed
Maximum duration 5 days
Ibuprofen PO 400-600 mg
Every 6-8 hours as needed
Avoid in acute kidney injury
Acetaminophen PO or IV 650-1000 mg
Every 6 hours as needed
Maximum 3000 mg per day for many adults
Refractory pain adjuncts
Ketamine low-dose infusion
Initiate 0.1-0.3 mg/kg/hour
Titrate by 0.05-0.1 mg/kg/hour every 30-60 minutes
Stop for emergence reaction or intolerable dizziness
Lidocaine infusion
Consider per institutional protocol
Contraindications with severe heart block or seizure risk
Pruritus and nausea management
Ondansetron PO or IV 4-8 mg
Every 8 hours as needed
Diphenhydramine PO or IV 25-50 mg
Prefer non-sedating strategies when possible
Fluids and oxygen
Supportive care
Fluids
Oral hydration preferred when tolerating PO
IV isotonic crystalloid for dehydration
250-500 mL boluses with reassessment
Avoid routine aggressive overhydration
Oxygen
Supplemental oxygen for hypoxia
Target SpO2 92% or higher
No routine oxygen for normal saturation
Temperature and comfort
Warm environment
Avoid cold exposure triggers
Acute chest syndrome pathway
Acute chest syndrome management
Respiratory support
Oxygen escalation to maintain SpO2 92% or higher
Incentive spirometry
10 breaths every 2 hours while awake
Antibiotics when suspected
Ceftriaxone IV 2 g daily
Plus azithromycin IV or PO 500 mg daily
Alternative for beta-lactam allergy
Levofloxacin IV or PO 750 mg daily
Bronchodilator trial
Wheeze or known asthma
Transfusion strategy
Simple transfusion
Symptomatic anemia or hemoglobin significantly below baseline
Exchange transfusion
Severe hypoxia
Rapid progression
Multilobar infiltrates
Stroke and neurologic emergency pathway
Stroke management
Neuroimaging
Immediate CT head
MRI if available and nondiagnostic CT with persistent concern
Transfusion
Exchange transfusion for suspected ischemic stroke
Target HbS fraction per hematology protocol
Antithrombotics
Per stroke team after hemorrhage exclusion
Transfusion principles
RBC transfusion decision-making
General targets
Avoid post-transfusion hemoglobin above 100 g/L in HbSS to reduce hyperviscosity risk
Indications for simple transfusion
Symptomatic anemia
Perioperative optimization
Mild to moderate acute chest syndrome
Indications for exchange transfusion
Stroke or TIA concern
Severe acute chest syndrome
Multiorgan failure syndrome
Alloimmunization mitigation
Extended phenotype-matched units when feasible
Early hematology involvement with complex antibody history
Infection and fever
Fever management
Sepsis evaluation and antibiotics when indicated
Early broad-spectrum antibiotics for sepsis physiology
Source-directed antibiotics for suspected pneumonia or UTI
Asplenia risk
Lower threshold for bacteremia evaluation
VTE prophylaxis and mobility
Thrombosis prevention
Pharmacologic prophylaxis for admitted adults unless contraindicated
Enoxaparin SC 40 mg daily
Renal adjustment per protocol
Early mobilization
As tolerated when pain controlled
Priapism
Priapism pathway
Initial measures
Analgesia
Hydration
Oxygen for hypoxia
Urology escalation
Ischemic priapism 4 hours or longer
Aspiration and intracavernosal phenylephrine per urology protocol
Avoidance and safety
High-risk therapies to avoid
Meperidine
Neurotoxic metabolite and seizure risk
Routine systemic corticosteroids for uncomplicated pain crisis
Rebound pain and readmission risk
Opioid safety
Sedation monitoring
Hold escalation for respiratory depression
Naloxone availability
IV 0.04 mg titrated for opioid-induced respiratory depression
Special Populations
Pregnancy
Pregnancy considerations
Maternal-fetal risks
Higher acute chest syndrome risk
Higher VTE risk
Medication considerations
NSAID avoidance in later pregnancy per obstetric guidance
Opioid use with monitoring for oversedation
Disposition bias toward admission
Lower threshold with fever, hypoxia, or reduced fetal movement
Geriatric
Older adult considerations
Comorbidity burden
Chronic kidney disease and NSAID risk
Heart failure and fluid sensitivity
Medication sensitivity
Lower opioid starting doses and slower titration
Delirium risk with sedatives and antihistamines
Pediatrics
Pediatric considerations
Weight-based dosing
Morphine IV 0.05-0.1 mg/kg
Hydromorphone IV 0.01-0.015 mg/kg
Splenic sequestration vigilance
Rapid pallor and lethargy
Enlarging spleen on exam
Acute chest syndrome monitoring
Lower threshold for admission with fever or cough
Background
Epidemiology
Epidemiology overview
Disease burden
High ED utilization and recurrent admissions in severe genotypes
Vaso-occlusive pain as most common acute presentation
Risk patterns
Increased crisis frequency with dehydration and infection
Higher complication risk in HbSS and HbS beta zero thalassemia
Pathophysiology
Pathophysiology essentials
Vaso-occlusion mechanism
Sickling under deoxygenation and acidosis
Endothelial activation and adhesion
Microvascular obstruction leading to ischemic pain
Hemolysis consequences
Nitric oxide scavenging and vasoconstriction
Pulmonary hypertension risk
Acute chest syndrome mechanism
Infection trigger
Fat embolism trigger
Hypoventilation from pain and atelectasis
Therapeutic Considerations
Treatment rationale
Early opioid analgesia
Prevents pain amplification and facilitates ventilation
Multimodal analgesia
Opioid-sparing and improved functional outcomes
Judicious fluids
Dehydration correction without pulmonary edema risk
Incentive spirometry
Atelectasis prevention and acute chest syndrome risk reduction
Transfusion strategy
Oxygen delivery improvement and HbS reduction when severe complications occur
Patient Discharge Instructions
copy discharge instructions
Home plan
Pain control plan
Take prescribed pain medicines exactly as directed
Use scheduled acetaminophen if recommended
Use NSAID only if approved for you
Hydration and rest
Drink fluids regularly
Avoid cold exposure
Breathing exercises
Incentive spirometer if provided
Deep breathing and gentle walking as tolerated
Follow-up
Contact hematology or primary care within 1-3 days
Refill planning to avoid running out of pain medicine
Return to ED now for red flags
Fever 38.0 C or higher
Chest pain
Trouble breathing
Oxygen level low if you monitor it
New cough
Severe headache
Weakness, numbness, speech trouble, or vision change
Fainting or severe dizziness
Uncontrolled pain despite home plan
Priapism 4 hours or longer
New one-sided leg swelling
Pregnancy with decreased fetal movement or vaginal bleeding
References
Guidelines and core sources
Guideline set
NHLBI Evidence-Based Management of Sickle Cell Disease
Acute pain episode management framework
Transfusion indications for acute complications
American Society of Hematology sickle cell guidelines
Acute pain management recommendations
Transfusion support recommendations
British Society for Haematology sickle cell guidance
Acute chest syndrome management
Transfusion and exchange transfusion pathways
Evidence grading conventions
Evidence labeling used in this document
Class I recommendation
Strong benefit and general agreement
Class IIa recommendation
Moderate benefit and supportive evidence
Class IIb recommendation
Possible benefit with limited evidence
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.