What is the preoperative management for patients with sickle cell (sickle cell disease) anemia undergoing surgery?

Preoperative Management of Sickle Cell Anemia

All patients with sickle cell disease undergoing surgery requiring general anesthesia lasting longer than 1 hour should receive preoperative transfusion to target hemoglobin of 100 g/L, with the transfusion method (simple vs. exchange) determined by baseline hemoglobin, surgical risk level, and genotype. 1

Preoperative Assessment and Planning

Multidisciplinary Team Coordination

• Identify a nominated lead hematologist (or pediatric hematologist for children) who will determine the perioperative transfusion plan before surgery. 1, 2
• Schedule pre-assessment clinic review with hematology input for all elective cases. 1, 2
• Notify the acute pain team in advance, particularly for patients with chronic pain history undergoing major surgery. 1, 2
• Ensure surgery is performed at centers with sickle cell disease experience; for emergencies elsewhere, contact specialists through haemoglobinopathy network arrangements. 1

Hemoglobinopathy Screening and Documentation

• Screen all at-risk patients for hemoglobinopathy before surgery, avoiding unnecessary repeat testing. 1, 2
• Document the sickle cell diagnosis clearly in patient records and communicate to all relevant teams: haematology, anesthesia, transfusion laboratory, waiting list coordinators, pre-assessment, and ward nursing staff. 1
• Patients should carry a transfusion card with allo-antibody information and full red cell phenotype or genotype. 1

Surgical Scheduling Considerations

• Schedule patients early on the operating list to avoid prolonged starvation. 1, 2
• Avoid last-minute administrative cancellations, especially if the patient has received preparatory transfusion. 1, 2
• Postpone routine surgery if the patient is febrile or experiencing a painful crisis. 1, 2

Preoperative Transfusion Strategy

Indications and Timing

The American Society of Hematology recommends preoperative transfusion for surgeries requiring general anesthesia lasting >1 hour, though the evidence certainty is very low. 1 The Association of Anaesthetists provides more specific guidance based on the landmark Howard trial showing compelling evidence for transfusion in HbSS patients undergoing low- and medium-risk surgery. 1

Transfusion Method Selection

For patients with baseline Hb <90 g/L:

• Perform simple "top-up" transfusion to target Hb of 100 g/L. 1
• Avoid increasing Hb by more than 40 g/L in a single transfusion episode to prevent hyperviscosity. 1

For patients with baseline Hb 90-100 g/L:

• Simple transfusion is appropriate for low- to medium-risk surgery. 1
• Consider exchange transfusion for high-risk procedures. 1

For patients with baseline Hb >100 g/L (common in HbSC genotype):

• Use red cell exchange (RCE) transfusion rather than simple transfusion to avoid excessive hemoglobin levels and hyperviscosity. 1
• Partial exchange can allow higher target Hb (>100 g/L) by reducing HbS contribution to viscosity. 1

For high-risk surgery (cardiac, neurosurgery) or patients with significant comorbidities:

• Exchange transfusion should be considered regardless of baseline Hb. 1
• Target HbS% <30% for patients on long-term transfusion programs (e.g., stroke prevention). 1

Blood Product Requirements

• Use HbS-negative donor red cells compatible for ABO, Rh, and Kell antigens plus additional known allo-antibodies. 1, 3
• Blood should ideally be <10 days old for simple transfusion and <8 days old for exchange transfusion. 1
• If transfused within 28 days, allow minimum 72 hours between group-and-save specimen and cross-match for surgery. 1
• Alert the transfusion laboratory early as special blood supplies may need ordering, particularly for patients with allo-antibodies or complex requirements. 1

Emergency Surgery Transfusion Protocol

• If Hb <90 g/L: Give simple top-up transfusion to 100 g/L preoperatively if this will not delay surgery. 1
• If Hb ≥90 g/L and low-risk surgery: Reasonable to proceed without delay and transfuse intra- or postoperatively if necessary. 1
• Contact consultant hematologist if any doubt exists about transfusion preparation. 1

Risk Stratification by Surgery Type

Low-Risk Procedures

Surgery involving eyes, skin, nose, ears, distal extremities, dental, perineal, and inguinal areas (e.g., inguinal hernia repair, myringotomy, dilatation and curettage). 1

• Transfusion beneficial for HbSS patients (reduces complications from 12.9% to 4.8%). 4

Moderate-Risk Procedures

Surgery involving throat, neck, spine, proximal extremities, genitourinary system, and intra-abdominal areas (e.g., cesarean section, splenectomy, cholecystectomy, hip replacement). 1

• Preoperative transfusion strongly recommended. 1

High-Risk Procedures

Cardiac surgery and neurosurgery. 1

• Exchange transfusion preferred regardless of baseline Hb. 1

Genotype-Specific Considerations

HbSS (Sickle Cell Anemia):

• Most severe phenotype with typical Hb 60-90 g/L. 3
• Requires most aggressive preventive measures and transfusion support. 3
• No randomized trials conducted in non-HbSS genotypes. 1

HbSC Disease:

• Higher baseline Hb (up to 120 g/L). 1
• Preoperative transfusion beneficial for all surgical risk levels. 4
• Exchange transfusion preferred over simple transfusion due to elevated baseline Hb. 1, 3

HbSβ⁰-Thalassemia:

• Similar severity to HbSS with 80-90% HbS. 3
• Manage similarly to HbSS patients. 3

Baseline Assessment and Optimization

Clinical Evaluation

• Document baseline oxygen saturation and continue monitoring if sedative premedication given. 2
• Assess functional status and cardiovascular risk. 5
• Screen for obstructive sleep apnea. 5
• Review transfusion history and prior surgical complications. 5

Medication Management

• Continue baseline hydroxyurea therapy perioperatively. 3
• Patients with high HbF levels (>8%) tend to have milder disease. 3

Laboratory Studies

• Review baseline hemoglobin and HbS percentage. 5
• Ensure recent group-and-save with antibody screen. 1

Critical Pitfalls to Avoid

• Do not perform exchange transfusion routinely without clear indication - one study showed 80% severe complication rate with exchange transfusion versus 0% with simple transfusion in appropriate patients. 6
• Avoid HbS% >40% preoperatively - associated with higher postoperative complication rates. 7
• Do not delay emergency surgery for transfusion if Hb ≥90 g/L and surgery is low-risk. 1
• Never use regional anesthesia preferentially - associated with higher complication rates compared to general anesthesia in sickle cell patients. 4
• Recognize that most complications occur postoperatively; maintain low threshold for HDU/ICU admission. 1, 2