DiGeorge Syndrome (DGS)

Get an ionized calcium and an ECG before induction - Parathyroid hypoplasia means these patients run on no calcium reserve, and hypoparathyroidism tends to declare itself further with age. The acute manifestations are the ones that will find you intraoperatively: seizures, laryngospasm, prolonged QT and tetany. An ionized calcium and a rhythm strip read for QT are the two numbers worth having before the patient is asleep. Confirm their calcium and vitamin D supplementation has actually been taken, and do not overshoot correcting it — hypercalcemia is damaging in its own right.

Transfusion will drop the calcium further - Citrate in stored products chelates ionized calcium, and a patient with no parathyroid reserve cannot compensate. Watch for hypotension with a narrow pulse pressure, arrhythmias and tetany, and replace on the order of 10 to 20 mL of calcium gluconate or 2 to 5 mL of calcium chloride per 500 mL of blood given, checking ionized calcium rather than dosing blind.

Order irradiated cellular blood products - Thymic hypoplasia is a congenital T-lymphocyte immunodeficiency, which is a hard indication for irradiation of red cells, platelets, whole blood and granulocytes. Irradiation is what prevents transfusion-associated graft-versus-host disease, which carries over 90% mortality. Leukoreduction does not prevent it — a leukoreduced unit is not a substitute. Tell the blood bank at booking, because irradiation delays release and shortens shelf life, and you do not want to discover the requirement while the patient is bleeding.

Irradiated units run hot on potassium - Irradiation raises the potassium in the product, and posttransfusion hyperkalemia is a described risk specifically in neonates, in renal dysfunction, and with massive transfusion — which describes most of the DGS patients who need blood. Check a potassium alongside the calcium.

Find the cardiac lesion before you plan anything - Conotruncal defects are the main driver of morbidity and mortality here. The lesions that travel with the deletion are tetralogy of Fallot, pulmonary atresia, truncus arteriosus, interrupted aortic arch and ventricular septal defect; a right aortic arch is also associated. Get the most recent echocardiogram and the operative report and let the specific lesion and its repair state, not the syndrome label, set your hemodynamic targets. Interrupted aortic arch and truncus arteriosus have their own library entries — read the one that matches the patient.

De-bubble every line - Any lesion capable of right-to-left shunting will convert air in the tubing into a paradoxical arterial embolus. Purge lines, use filters, and if you are siting an epidural use loss of resistance to saline rather than air.

Airway problems are palatal and small-mouthed - More than 90% have a long narrow face, tubular nose and small mouth. Cleft palate and velopharyngeal insufficiency are core features. Look in the mouth preoperatively for an overt or submucous cleft and note the mouth opening; a small oral aperture with a repaired or unrepaired palate is what limits laryngoscopy, and a video laryngoscope earns its place.

Treat them as a reflux and aspiration risk - Nasopharyngeal muscle weakness causes the feeding difficulty in this syndrome, and it is routinely managed with thickeners and anti-reflux medication. Ask what the child is on. Weak pharyngeal muscle plus a palatal defect is a poor airway protector.

Check a platelet count before regional or a central line - When the GPIBB gene falls inside the deletion, patients have thrombocytopenia with large platelets and a real propensity for bleeding and epistaxis. Immune thrombocytopenia and autoimmune hemolytic anemia are both more common. Look at the count and the smear rather than assuming a normal hemostatic starting point.

Keep everything sterile and expect infection to behave badly - The degree of immunodeficiency tracks the extent of thymic hypoplasia. Viral infections last longer and pick up superimposed bacterial infection, autoimmune disease affects about 10%, and hematologic malignancy risk is raised. Complete DGS with no thymic tissue is under 1% of cases but behaves like severe combined immunodeficiency, and those children die by 12 months without thymic or hematopoietic transplantation. Full barrier technique for every line.

Thymus transplantation is now an anesthetic you may be asked to give - It is FDA-approved standard care for complete DGS, performed under general anesthesia with the tissue implanted into the quadriceps. Autoimmune sequelae in survivors are frequent — hemolysis, thyroiditis, thrombocytopenia, enteropathy, neutropenia — so the postoperative picture is not a clean one.

Expect the adult patient to be different from the child - Many with partial DGS reach adulthood undiagnosed. Psychiatric disease is common, with a 30-fold increased risk of schizophrenia, and hypothyroidism and hypoparathyroidism develop over time. In an adult presenting with the deletion, review the psychiatric medication list for interactions and QT effects alongside the calcium.

DiGeorge syndrome (DGS) is a microdeletion at 22q11.2, present in about 90% of cases and the most common microdeletion syndrome in humans at roughly 1 in 4,000 to 6,000 live births. Loss of TBX1 and its neighbors derails neural crest migration into the third and fourth pharyngeal pouches, and everything the pouches were supposed to build fails together: middle and external ear, maxilla and mandible, palate, thyroid, parathyroids, thymus, aortic arch and cardiac outflow tract.

That single embryologic fact explains the whole perioperative picture and is worth carrying into the room. Parathyroid hypoplasia gives hypocalcemia with no reserve. Thymic hypoplasia or aplasia gives T-cell deficiency. Conotruncal maldevelopment gives the cardiac lesions. The old CATCH-22 mnemonic still holds — Conotruncal anomalies, Abnormal facies, Thymic hypoplasia, Cleft palate, Hypocalcemia, 22q11.2. Velocardiofacial syndrome and conotruncal anomaly face syndrome are the same deletion under different names.