Sickle Cell Disease 

 

 

Considerations 

 

  • Multisystem disease with end-organ dysfunction:

    • CNS: stroke

    • Cardiovascular: LV hypertrophy, high-output cardiac failure (anemia), myocardial infarction without coronary artery disease 

    • Respiratory: acute chest syndrome (ACS), restrictive lung disease (pulmonary fibrosis), pulmonary hypertension, RV hypertrophy, cor-pulmonale

    • Renal: renal failure, renal infarction 

    • Spleen: sequestration, infarcts; if splenectomy → ↓ immunity

  • Potential for perioperative exacerbations of vaso-occlusive crises:

    • Acute pain crisis

    • Acute chest syndrome

  • Chronic hemolytic anemia:

    • Chronic RBC transfusion & its complications (alloimmunization, iron overload, viral transmission)

  • Chronic pain & potential opioid tolerance

  • Preoperative optimization: consider preoperative transfusion for goal hematocrit: 30%, hemoglobin: 100 (see discussion in optimization)

  • Medications: immunosuppresants, antineoplastics

 

 

Goals

 

  • Avoid precipitants of sickle cell crisis:

    • ​Hypoxia

    • Vascular stasis

    • Hypothermia

    • Hypovolemia/hypotension

    • Acidosis

  • Optimize perioperative pain control 

  • Monitor for:

    • Vaso-occlusive crisis

    • Acute chest syndrome

    • Aplastic crisis

    • Splenic sequestration syndrome

    • Right upper quadrant syndrome 

 

 

Optimization (in consultation with hematology) 

 

  • Risk factors for acute pain crises:

    • Age, frequency of hospitalizations &/or transfusions for episodes of crisis, evidence of organ damage (e.g., low baseline oxygen saturation, elevated creatinine, cardiac dysfunction), history of central nervous system events, concurrent infection

  • Procedural risk for complications:

    • Low: minor surgery (e.g., inguinal hernia & extremity surgery)

    • Intermediate: intra-abdominal operations (e.g., cholecystectomy)

    • High: intracranial & intrathoracic procedures, hip surgery

  • Hematology consult, optimize treatment:

    • Hydroxyurea to ↑ fetal hemoglobin production

  • Cancel non-emergent cases if patient experiencing a crisis

  • Only low risk patients should be considered for outpatient surgery

  • IV fluid to avoid dehydration while NPO

  • Preoperative transfusion therapy:

    • Controversial without good evidence

    • Purpose is to correct pre-existing anemia, ↓ hemoglobin S concentration &  adult hemoglobin

    • Consider target hemoglobin 100 or hematocrit 30% for intermediate & high risk surgeries & always have blood available for any surgery

    • Exchange transfusions are not routinely recommended

 

 

Acute chest syndrome (ACS)

 

  • Background:

    • Second most common reason for hospitalization after vaso-occlusive crisis

    • Mortality 2-12%; accounts for 25% of deaths in sickle cell patients

    • Characterized by acute respiratory symptoms concurrent with new infiltrate on CXR

    • Spectrum of pathology:

      • Infection

      • Infarction (especially ribs)

      • Pulmonary sequestration

      • Fat embolism

    • Pulmonary vaso-occlusion due to sequestration of sickled cells in small pulmonary vessels

    • Infection or fat emboli may lead to vaso-occlusion & sequestration

    • Clinical picture: fever, tachypnea, pleuritic pain & cough 

    • CXR: normal to complete opacification but usually demonstrates a new lobar infiltrate:

      • Children: upper lobe disease common

      • Adults: multilobe & lower lobe disease more common

    • Strong relationship between ACS & stroke

  • Treatment:

    • ​​Admit to monitored setting, may need ICU

      • Hydration to euvolemia

      • Oxygen, noninvasive PPV if necessary 

      • Bronchodilators (even if not wheezing) 

      • Broad spectrum antibiotics: infection is one of the most common causes of ACS 

      • Transfusion: both simple & exchange transfusion:

        • Simple transfusion: goal is to ↑ hematocrit to > 30%:

          • Indications:

            • To improve oxygenation, particularly in patients with oxygen saturation below 92% on room air & to prevent progression to respiratory failure

            • For accentuated anemia, defined as a hematocrit that is 10% to 20% below the patient's usual hematocrit, or with a dropping hematocrit during hospitalization

            • Clinical or radiological progression of disease but not impending respiratory failure

            • For patients in whom exchange transfusion will be delayed; simple transfusions may be used to temporize the clinical situation until the exchange transfusion can be performed

        • Exchange transfusion: goal is to ↓  the level of hemoglobin S to < 30%:  

          • Indications:

            • Progression of ACS despite simple transfusion

            • Severe hypoxemia

            • Multi-lobar disease

            • Previous history of severe ACS or cardiopulmonary disease

      • Analgesia: adequate analgesia of spine, thoracic, & abdominal pain is important to prevent hypoventilation & atelectasis

      • Possibly inhaled nitric oxide for severe cases

 

 

Acute pain crisis (Vaso-occlusive crisis)

 

  • Anesthesia may be requested to assist with analgesia (e.g., patient-controlled analgesia)

  • Typically occurs in long bones, ribs, spine, or abdomen

  • Precipitants: infection, dehydration, hypothermia, hypoxia, stress, alcohol intake, menstruation

  • Bone pain from ischemia & infarction of marrow or cortex

  • Abdominal pain from bowel ischemia, organ infarction, or referred from the ribs

  • Severity of pain can range from annoying to disabling 

  • Treatment: rest, warmth, reassurance, analgesia, fluid replacement:

    • Oral analgesics may be sufficient for minor attacks

    • Opioids (IM, SC, IV, PO):

      • PCA opioids with baseline analgesia provided by background infusion or fentanyl patch

    • Acetaminophen & NSAIDs:

      • NSAIDS particularly good for bone pain

    • Ketamine as adjunct

    • Regional blocks as appropriate, epidural use has been reported

 

 

Pregnancy Considerations  

 

  • Interaction with pregnancy:

    • Pregnancy typically exacerbates the complications of sickle cell anemia

    • Maternal mortality is as high as 1%

    • Pulmonary embolism & infection are the leading causes of death

  • Management:

    • Hemoglobin goals:

      • > 80 for vaginal delivery 

      • > 100 for cesarean delivery

    • Epidural strongly recommended in labor to reduce stress/pain 

    • Safe to use either GA or neuraxial for cesarean section

    • Goals: avoid hypovolemia, hypoxemia, hypercarbia, hypothermia, pain, stress

 

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