Fibrinogen (Fbg) deficiency, either complete or incomplete, is a rare coagulopathy (1 in 1 million).1 Congenital Fbg deficiency is defined as absent plasma Fbg (afibrinogenemia), low plasma Fbg (hypofibrinogenemia), or dysfunctional Fbg (dysfibrinogenemia).2,3 Even patients with congenital afibrinogenemia, which is characterized by complete Fbg deficiency, can sometimes be asymptomatic. Although asymptomatic patients require no treatment, Fbg replenishment is necessary to maintain a plasma Fbg concentration of ≥100 mg/dL during major surgery and of ≥50 mg/dL during minor surgery or pregnancy.2–5 Surgical procedures are generally performed with the plasma Fbg concentrations maintained at 100–200 mg/dL, which are usually achieved following administration of an Fbg preparation at the dose of 50–100 mg/kg.2
Herein, we report the case of a patient with hypofibrinogenemia, who developed postoperative hemorrhage after tonsillectomy.
Written consent was obtained from the patient for publication of this report.
A 26-year-old male patient (height 158 cm, weight 76 kg, American Society of Anesthesiologists physical status II) was scheduled to undergo tonsillectomy. The patient had been detected to have low plasma Fbg concentrations during his childhood, but did not have a confirmed diagnosis of Fbg deficiency. Except for a little delay in coagulation observed when he sustained an injury, the patient had no other obvious bleeding tendency. There was no family history of Fbg deficiency or bleeding tendency.
Preoperative laboratory examination revealed no abnormalities, including of the prothrombin time or activated partial thromboplastin time, except for a low plasma Fbg concentration (<50 mg/dL, Clauss assay [Thrombocheck Fib, Sysmex Co, Ltd, Hyogo, Japan]). The patient was administered 3 g of an Fbg preparation (Fibrinogen HT I.V. 1 g “JB,” Japan Blood Products Organization, Tokyo, Japan, approximately 40 mg/kg) on the day of the operation, so as to increase the plasma Fbg concentration to the target level of 100 mg/dL. The plasma Fbg concentration increased to 85 mg/dL after the infusion; therefore, another 1 g of the Fbg preparation was administered just before the operation.
Anesthesia was induced with 150 mg of propofol, 0.1 mg of fentanyl, and 50 mg of rocuronium and maintained with 2% of sevoflurane in an oxygen–air mixture and 0.1–0.2 µg/kg/min of remifentanil. The patient was intubated with an 8-mm oral RAE tracheal tube (Polar Preformed Tracheal Tube; Smith Medical international Co, Ltd, Tokyo, Japan) which was fixed in the midline. The surgical time was 63 minutes, and the anesthesia time was 131 minutes. There was no significant intraoperative bleeding. The postoperative time course of the plasma Fbg concentration was as follows: 92 mg/dL immediately after the surgery, 96 mg/dL on day 2, and 100 mg/dL on day 4 after the surgery. Fbg monitoring was not performed on days 5 and 6. On day 6 after the surgery, the patient coughed out streaks of blood in the sputum. He was administered 4 units of fresh frozen plasma (not Fbg, because there was no stock in our hospital), because the bleeding, even though minor, was prolonged. The following day, on day 7, the plasma Fbg concentration was 68 mg/dL. Thereafter, the postoperative course was uneventful, and the patient was discharged on day 9.
We performed tonsillectomy in a patient with congenital hypofibrinogenemia. Congenital Fbg deficiency is defined as absent plasma Fbg (afibrinogenemia), low plasma Fbg (hypofibrinogenemia), or dysfunctional Fbg (dysfibrinogenemia).2,3 Although marked decrease of the plasma Fbg can cause bleeding, even complete deficiency of Fbg (afibrinogenemia) can sometimes be asymptomatic. Supplementation of Fbg is not required in asymptomatic patients, except at the time of surgery or during pregnancy. Because 20%–30% of patients with congenital afibrinogenemia exhibit a thrombotic tendency and a high rate of thrombosis after surgery, these patients should be monitored carefully for laboratory and clinical evidence of coagulation activation and clot formation.2 In regard to replacement therapy, replenishing Fbg to maintain a plasma concentration of ≥100 mg/dL during major surgery and of ≥50 mg/dL during minor surgery or the postoperative period is recommended.4,5 Because surgical procedures are generally performed with plasma Fbg concentrations maintained at 100–200 mg/dL, usually achieved by administration of 50–100 mg/kg, the patient should be administered 4–5 g of an Fbg preparation preoperatively. In addition, the patient should be administered Fbg, not fresh frozen plasma, for postoperative bleeding. The use of fresh frozen plasma and cryoprecipitate has declined because of the risk of volume overload and risks associated with infusion of large amounts of unnecessary plasma proteins.2
While postoperative bleeding after tonsillectomy should be considered as a complication, the bleeding risk associated with this surgery is generally not high. Considering the half-life of Fbg (3–4 days) and his preoperative plasma Fbg concentration, the plasma Fbg concentration of this patient was probably <50 mg/dL; therefore, it should be monitored for ≥6 postoperative days to ensure a target level of 50 mg/dL.
In the case reported herein, we performed Fbg replenishment to obtain a preoperative target plasma Fbg concentration of 100 mg/dL before tonsillectomy. However, prolonged bleeding was observed on the sixth postoperative day. In the perioperative management of patients with Fbg decline, we suggest that the plasma Fbg concentration be monitored for ≥6 postoperative days and that a target level of ≥50 mg/dL is ensured for minor surgery.
Name: Mariko Aoki, MD.
Contribution: This author helped perform the anesthetic management for the case and write the manuscript.
Name: Yoshimune Osaka, MD, PhD.
Contribution: This author helped write the manuscript.
Name: Kamon Ando, MD, PhD.
Contribution: This author helped manage the anesthetic management for the case.
Name: Yoshihisa Morita, MD, PhD.
Contribution: This author helped prepare the manuscript.
This manuscript was handled by: BobbieJean Sweitzer, MD, FACP.
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