Déficits rares de la coagulation et gestes invasifs

Thromboelastographic study of the snakebite-related coagulopathy in Djibouti

: Hemostasis disorders are one of the major clinical conditions of snakebites and are because of mechanisms which may disrupt vessels, platelets, clotting factors and fibrinolysis. Thromboelastography (TEG) could help to understand these effects in the clinical practice. A retrospective study reports a series of patients presenting a snakebite-related coagulopathy, treated with antivenom and monitored with conventional tests and TEG in a French military treatment facility (Republic of Djibouti, East Africa) between August 2011 and September 2013. Conventional coagulation assays (platelets, prothrombin time, activated partial thromboplastin time, fibrinogen) and TEG measurements were taken on arrival and at various times during the first 72 h of hospitalization, at the discretion of the physician. The study included 14 patients (median age 28 years). Bleedings were present in five patients. All patients received antivenom. A coagulopathy was present in all patients and was detected by both conventional assays and TEG. None exhibited thrombocytopenia. Prothrombin time and fibrinogen remained abnormal for most of patients during the first 72 h. The TEG profiles of 11 patients (79%) showed incoagulability at admission (R-time > 60 min). TEG distinguished 10 patients with a generalized clotting factor deficiency and 4 patients with an isolated fibrinogen deficiency after an initial profile of incoagulability. Hyperfibrinolysis was evident for 12 patients (86%) after Hour 6. Snake envenomations in Djibouti involve a consumption coagulopathy in conjunction with delayed hyperfibrinolysis. TEG could improve medical management of the condition and assessment of additional therapeutics associated with the antivenom.

Factor XIII deficiency in south of Tunisia

: Factor XIII deficiency is a rare autosomal recessive disorder of hemostasis characterized by a plasmatic factor XIII level less than 1% in homozygote and bleeding as of the youth. The aim of the study is to describe the clinical features and the outcome of the patients and to determine molecular characteristics. A retrospective study, was conducted on seven patients with factor XIII deficiency in the department of hematology and pediatrics, Hedi Chaker Hospital, Sfax, Tunisia during the period of 14 years (2001-2014). The activity of factor XIII in plasma of the patients was less than 1%. Seven patients from five unrelated families were recorded (four men and three women). Median age at diagnosis was 3.5 years. All patients had consanguineous parents. Six patients presented umbilical bleeding and only three patients had intracranial bleeding. Other bleeding features were seen, including skin and mucosal bleeding, muscular hematoma, and splenic rupture. Recurrent abortions were observed in one patient. The standard screening tests were normal. Genetic analysis identified two mutations interesting the subunit A of factor XIII. All patients received transfusion of fresh frozen plasma monthly. One patient was died because of intracranial hemorrhage.Factor XIII deficiency is a rare bleeding disorder which frequently increases in areas with high consanguinity. In our study, we identified a founder mutation. The prognosis of the disorder is related to hemorrhagic complications especially to life-threatening intracranial bleeding. Prophylaxis consists of factor XIII concentrate or recombinant factor XIII. If these are unavailable, fresh frozen plasma may be used.

[Hereditary heterozygous factor VII deficiency in patients undergoing surgery : Clinical relevance]

BACKGROUND

A hereditary deficiency in coagulation factor VII (FVII) may affect the international normalized ratio (INR) value. However, FVII deficiency is occasionally associated with a tendency to bleed spontaneously. We hypothesized that perioperative substitution with coagulation factor concentrates might not be indicated in most patients.

METHODS

In this retrospective data analysis, we included all patients with hereditary heterozygous FVII deficiency who underwent surgical procedures at the University Hospital Basel between December 2010 and November 2015. In addition, by searching the literature, we identified publications reporting patients with FVII deficiency undergoing surgical procedures without perioperative substitution.

RESULTS

We identified 22 patients undergoing 46 surgical procedures, resulting in a prevalence of 1:1500-2000. Coagulation factor concentrates were administered during the perioperative period in 15 procedures (33 %), whereas in the other 31 procedures (66 %), FVII deficiency was not substituted. No postoperative bleeding or thromboembolic events were reported. In addition, we found no differences in pre- and postoperative hemoglobin and coagulation parameters, with the exception of an improved postoperative INR value in the substituted group. In the literature review, we identified five publications, including 125 patients with FVII deficiency, undergoing 213 surgical procedures with no perioperative substitution.

DISCUSSION

Preoperative substitution using coagulation factor concentrates does not seem to be mandatory in patients with an FVII level ≥15 %. For decision-making on preoperative substitution, patient history of an increased tendency to bleed may be more important than the FVII level or increased INR value.

[Management of comorbidity and preoperative treatment in ambulatory surgery?]

Prevention of postoperative exacerbation of chronic medical disease requires high standard of safety and quality of care in ambulatory surgery and anesthesia. Age is not a major criterion for selection for ambulatory surgery. Ambulatory surgery may be considered for patients with ASA score I, II or III with stable medical conditions. Preoperative medical condition is not a contra-indication to ambulatory surgery, (except severe or end stage) as long as perioperative organization and patient compliance to perioperative instructions are controlled. In patients with major comorbidity, ambulatory surgery should be considered instead of conventional hospitalization. Preop treatment must be maintained during the perioperative period. Their interruption does not provide any benefit and could exacerbate an otherwise stable chronic disease.