Journal: Can J Anesth 55(1):47-51, 2008
Reprint: Dept of Pediatric Anesthesia, Room 11.7, British Columbia's Children's Hospital, 4480 Oak Street, Vancouver, British Columbia V6H 3V4, Canada (R Purdy, FRCP(C))
Faculty Disclosure: Abstracted by T. Tilton, who has nothing to disclose.
Hemophilia B is a recessive hemorrhagic disorder characterized by a deficiency of factor IX which occurs in 1/25,000-35,000 male births. Treatment with IX factor can be complicated by the appearance of an inhibitor against the administered factor in 3-5% of patients. The authors describe a case of suc¬cessful perioperative hemostatic management for scoliosis surgery in a 14½-yr-old Jehovah’s Witness boy with severe hemophilia B. The patient's pertinent history included growth hormone deficiency, hypothyroidism, occasional reactive airway disease, learning difficulty, and seizure disorder. His medications consisted of clobazam, phenytoin, levo¬thyroxine, salbutamol, multivitamins with iron, and growth hormone injections.
The patient experienced multiple bleeding episodes, none of which were treated with factor IX concen¬trate, because the family refused treatment with plasma-derived factors due to religious convictions. They did, however, accept therapy with recombinant factor IX concentrate (rFIX). During his 10th year, he received 3 infusions of rFIX but began coughing, gagging, and retching and became cyanotic and diaphoretic. A severe allergic reaction was diagnosed and he was treated with IV diphenhydramine; no further rFIX was given. Serum testing revealed that the patient had an immediate-acting inhibitor. He was then given activated recombinant human blood coagulation factor VII (rFVIIa) for on-demand hemostasis management. Juvenile onset idiopathic scoliosis was also diagnosed at age 10 and remained stable until age 14, at which time surgical correction was scheduled.
Prior to surgery, the surgeon consulted with the family and the church elders. All agreed to minimize the possibilities of conflicting philosophies by maxi¬mizing preoperative hemoglobin, minimizing intraop¬erative blood loss, and termination of the procedure should a trend in blood loss occur that might necessi¬tate transfusion, and to consider transfusion only in a life-threatening situation. Preoperative hemoglobin concentration was optimized with erythropoietin 300 U/kg given 3 times per week, and oral iron syrup at a dose of 5 mL tid, for 3 weeks prior to surgery. Two days preoperatively, coagulation labs revealed the need for desensitization with rFIX 120 U/kg along with diphenhydramine and hydrocortisone. Tolerance was maintained using rFIX q12 hr. On the day of surgery, coagulation studies were within normal limits and factor IX level was >100% and factor IX inhibitor level was 0.20 BU/mL.
An infusion of rFIX was given immediately pre¬operatively. General anesthesia was induced and invasive monitoring placed. Tranexamic acid 10 mg/kg IV was given as a bolus followed by an infusion at 2 mg/kg/hr. Operative time was 4 hours for posterior spinal fusion at T2-L1. Hemostasis was aided by local infiltration of 1:500,000 epinephrine, monopolar cautery, and the use of an argon gas coagulator. Intraoperative blood loss was approxi¬mately 350 mL (12% of total blood volume). Coagulation studies were normal, and no blood was transfused.
Postoperative management consisted of rFIX, tranexamic acid, erythropoietin and rFVIIa, diphen¬hydramine, hydrocortisone. On day 3, erythropoietin was discontinued and oral iron restarted. On day 4, the patient's activated partial thromboplastin time (APTT) increased abruptly, which signaled the onset of an anamnestic FIX inhibitor; from that point on, IV rFVIIa 4.8 mg (approximately 100 mcg/kg) replaced the rFIX. Tranexamic acid (1 g po q8 hr) was administered for 2 weeks postoperatively. The patient remained stable and was discharged on day 11.
In conclusion, the use of rFIX, rFVIIa, erythro¬poietin, iron, and tranexamic acid perioperatively may be a viable and safe option for hemophilia patients with inhibitors, who refuse blood products. |
