Sickle Cell Crises, TTP/HUS & DIC

Simultaneous Triage & Phenotype Recognition:
• Sickle Cell Acute Chest Syndrome (ACS): Apply HFNC 40–60 L/min (FiO₂ 0.40–1.0) to keep SpO₂ ≥ 95%.
• Suspected TTP: Hold ALL platelet transfusions immediately.
• Fulminant DIC: Activate hemorrhage/transfusion protocol if actively bleeding.

• Pulse oximetry, continuous telemetry
• Non-invasive BP cuff
• HFNC circuit or BiPAP setup

Prevent hypoxia-induced hemoglobin S (HbS) deoxy-polymerization in ACS [1]; prevent catastrophic microvascular platelet-rich thrombi propagation in TTP [4].

[1,4]

Vascular Access & Critical Diagnostic Blood Draw:
• Insert 2× large-bore peripheral IVs (16–18 G).
• TTP/SCD Critical Draw: Draw CBC with diff, reticulocyte count, peripheral blood smear, LDH, haptoglobin, indirect bilirubin, fibrinogen, D-dimer, PT/INR, aPTT, type & crossmatch (extended phenotype: C, E, Kell for SCD), and citrated plasma for ADAMTS13 activity/inhibitor BEFORE any plasma or blood product administration.

• 2× 16–18 G IV catheters
• Blue-top (3.2% sodium citrate), Lavender-top (EDTA), Pink-top (Crossmatch)
• Blood culture bottles × 2 sets

Preserve baseline ADAMTS13 enzymatic activity level and alloantibody profile prior to exogenous plasma dilution; establish baseline ISTH DIC and PLASMIC score variables [4,6,8].

[1,4,8]

First-Line Targeted Pharmacotherapy (Within 30 Min):
• SCD VOC / ACS: Morphine 0.1 mg/kg IV bolus (Max 10 mg initial bolus) OR Hydromorphone 0.015 mg/kg IV (Max 1.5 mg); repeat q15–20 min. If no IV access within 15 min, give Intranasal Fentanyl 1.5 mcg/kg (Max 100 mcg) [1].
• Suspected TTP (PLASMIC Score ≥ 5): Methylprednisolone 1,000 mg IV over 30 min [4].

• Crash-cart opioid box
• Mucosal Atomization Device (MAD) for IN fentanyl
• Methylprednisolone 1 g in 100 mL NS

Suppress nociceptive sympathetic surge and prevent pain-induced hypoventilation/atelectasis in SCD [1]; arrest B-cell autoantibody production against the ADAMTS13 spacer domain in TTP [4].

[1,4]

Empiric Antimicrobials & Careful Volume Modulation:
• SCD ACS / Fever (≥ 38.5°C): Ceftriaxone 2 g IV (50 mg/kg peds, Max 2 g) PLUS Azithromycin 500 mg IV (10 mg/kg peds, Max 500 mg). Add Vancomycin 15–20 mg/kg IV if MRSA risk or critically ill.
• SCD Fluid Rule: Infuse hypotonic maintenance (D ½NS at 1–1.5× maintenance, ~100–125 mL/hr). Avoid aggressive NS boluses unless overtly hypotensive [1].

• Broad-spectrum IV antibiotics
• Volumetric infusion pump
• Bedside POCUS (lung B-lines, IVC, RV strain)

Eradicate encapsulated organisms (S. pneumoniae, H. influenzae) and atypical pathogens (Mycoplasma, Chlamydia) triggering ACS; prevent hyperchloremic acidosis and hydrostatic pulmonary edema that worsen HbS sickling [1,2].

[1,2]

Definitive Mobilization (Pheresis & Blood Bank):
• ACS (Hb < 10 g/dL & ≥ 1 g/dL below baseline) or SCD Stroke: Mobilize Hematology for emergent Automated Red Cell Exchange Transfusion (target HbS < 30%, Hb 10 g/dL) [2,3].
• TTP: Place US-guided IJ/femoral apheresis catheter. Initiate Therapeutic Plasma Exchange (TPE 1.5× plasma volume = 60 mL/kg with FFP) + Caplacizumab 11 mg IV bolus 15 min prior to TPE [4,5].
• Bleeding DIC: Transfuse Cryoprecipitate 10 units (if Fibrinogen < 150 mg/dL), FFP 15 mL/kg (if INR > 1.5), Platelets 1 apheresis unit (if < 50,000/μL) [8].

• 12–14 Fr dual/triple-lumen apheresis catheter
• Linear ultrasound probe (7–12 MHz)
• Caplacizumab 11 mg vial

Rapidly lower blood viscosity and microvascular occlusion in SCD [2]; remove anti-ADAMTS13 IgG autoantibodies, replenish native ADAMTS13, and block vWF-A1/GpIb-IX-V binding in TTP [4,5]; restore hemostatic coagulation factors in consumptive DIC [8].

[2,4,5,8]