Matthew Kuestner, M.D., attending anesthesiologist at Kosair Children’s Hopsital, overviews sickle cell disease and anesthetic implications for pediatric patients. Dr Kuestner is a board certified pediatric anesthesiologist and a Diplomate of the American Board of Anesthesiology.
Sickle Cell Disease – Dr. Kuestner
Sickle Cell Disease affects kids as well as adults. Problems related to sickle cell is seen more as people age.
Scenario: A 7yr old boy presenting for a tonsil and adenoidectomy, for Obstructive Sleep Apnea. They have a history of sickle cell disease and a few crises’ but none in the past few months. Hemoglobin while taking hydroxyurea is 10.
Question: Prior to receiving surgery all of the following are true except?
A: He should have hematology consult preoperatively.
B: He does not require a transfusion since his hemoglobin is 10.
C: A hemoglobin electrophoresis should be obtained.
D: Surgery should not be done in an ambulatory center.
Sickle Cell Disease is not just a simple erythrocyte deformation that makes cells that look like sickles.
It involves hemolysis, anemia, microvascular occlusion and recurrent ischemic injury in all organ systems.
If you think of it as just a blood problem you are missing what is really happening.
It is the leading cause of morbidity and mortality among African-Americans.
Acute complications of sickle cell disease that are relevant to pediatric anesthesia.
- Acute Splenic Sequestration this usually occurs in children age 5 months to 2 years. But may occur as late as the teenage years in children with sickle thalassemia.
- This results from the pooling of large quantities of blood in the spleen and leads to shock with profound anemia.
- Aplastic Crisis – Results with the normal brisk reticulocytosis that is associated with sickle cell disease is suppressed. So they are not forming red blood cells quickly enough. This happens when the have a viral infect with parvovirus b19.
- Hemolytic Crisis – Occurs in patients that have an abrupt increase in hemolytic stress, such as infection or medication induced. Many of the patients are also deficient in the enzyme glucose 6 phosphate dehydrogenase.
- Sepsis / Septic Shock are serious acute complications. They generally experience autoinfarction of the spleen in early childhood and they are rendered susceptible to encapsulated organism infections. Aseptic techniques and wound infection prophylaxis is critical.
- Vaso-Occlusive Crisis – Are episodes of painful ischemia, and tissue infarction that result from small vessel occlusion by sickle cells.
- Most types of the occlusive crises include: dactylitis, priapism in males, stroke, and acute chest syndrome.
Chronic complications relevant to pediatric anesthesia.
- Can apply to pretty much all organ systems, decrease growth and maturation, increased nutritional requirements, retinopathy, stroke, cognitive dysfunction, cardiac dysfunction, elevated pulmonary vascular resistance, chronic lung injury, diminished renal tubular dysfunction, bone and joint destruction, leg ulcerations, splenic infarction.
- Mostly importantly to the perioperative management is the chronic changes to the cardiovascular, respiratory, and renal systems.
- The elevated pulmonary vascular resistance in childhood is a predictor of premature death.
Treatment of the Crises include:
- Intravascular volume expansion.
- Transfusion of red blood cells.
- Treatment of the infection.
- Stopping the offending medications.
Preop on children with Sickle cell.
- Most patients are now identified with newborn electrophoresis if they have sickle cell or not.
- Dehydration may predispose you to a vaso-occlusive crisis and acute chest syndromes.
The most debated topic over the perioperative management of sickle cell patients is the prophylactic preoperative blood transfusion.
Different Strategies from blood transfusion in sickle cell patients.
- Simple transfusions – The goal is to get a hemoglobin of 10, with no regard to the final percentage of HbS.
- Aggressive transfusions – Repeated simple transfusions, or acute exchange transfusions with goal hemoglobin being 10 and the HbS percentage being less than 30.
The rationale behind preoperative blood transfusions in both cases is to increase the oxygen carrying capacity of the blood and in the case of aggressive transfusion decreasing the percentage of HbS in circulation to prevent sickling.
Risk of preoperative blood transfusions.
- You can acquire blood born infections.
- Hemolytic transfusion reactions.
- (TRALI) Transfusion-Related Acute Lung Injury.
- Iron over load
- Alloimmunization to the foreign RBC antigens which may lead to difficulty cross matching later.
Typically patients with sickle cell disease undergoing procedure with moderate risk (e.g. laparotomy, thoracotomy, tonsillectomy and adenoidectomy) are managed with simple transfusions to correct the anemia.
High risk patients (e.g. those with stroke, recurrent acute chest syndrome) or patients undergoing high risk procedures (e.g. cardiovascular, cerebrovascular) may require and aggressive exchange transfusion approach to decrease their HbS percentage.
- If the patient has sickle cell trait only. Usually no risk or issue of sickling unless their sats are under 40%.
- In sickle cell disease hydroxyurea is a medication that is going to stimulate Hb-F, the fetal hemoglobin production. An increase of Hb-F from 5% to 15%, decrease the incidence of Acute Chest Syndrome by half in all age groups.
- Tonsillectomy, adenoidectomy, laparotomy, thoracotomy may need a transfusion to a hemoglobin greater than 10.
- Oxygenation, Hydration and Normothermia and all critical in sickle cell patients.
Post-op pain control and oxygen monitoring is very important in the patients.