Disseminated intravascular coagulation: SAQ

This boy has the acute, fulminant, thrombosis-dominated disseminated intravascular coagulation of meningococcal sepsis. He is in septic shock, with the purpura fulminans and the digital ischaemia, the thrombocytopenia, the prolonged prothrombin time, the low fibrinogen, the strongly raised D-dimer, and the fragmented red cells on the film. The ISTH overt-DIC score is well above five points, and the management rests on the cause-driven principle. [1][2][3]

Question 1 (10 marks)

Outline the diagnosis, the immediate management, and the resuscitation for this boy, justifying each step with the relevant evidence. [2]

A full-mark answer addresses the ISTH score, the cause-driven resuscitation, the components for the bleeding, and the heparin for the purpura fulminans. [1]

Diagnosis and the ISTH overt-DIC score (3 marks). This is disseminated intravascular coagulation, an acquired, trigger-driven syndrome of the systemic intravascular coagulation. The ISTH overt-DIC score totals the platelet count, the fibrinogen, the D-dimer, and the prothrombin time, and a score of five points or more, in a child with a compatible trigger, defines the overt disease. This boy scores two for the platelets under fifty, one for the fibrinogen under one gram per litre, three for the strongly raised D-dimer, and at least one for the prolonged prothrombin time, for a total well above five, and the septic shock with the purpura fulminans is the trigger. The fragmented red cells on the film are the microangiopathic haemolysis. [1][2]

The cause-driven resuscitation (4 marks). The definitive treatment of disseminated intravascular coagulation is the treatment of the trigger, and this boy has the septic shock, so the first action is the broad-spectrum antibiotics within the first hour, the fluid resuscitation, and the vasopressors, alongside the source control and the paediatric intensive-care referral. The DIC does not resolve until the trigger is removed, and every other measure buys time for the cause treatment to work. The British Committee for Standards in Haematology guideline of Levi and colleagues sets out this cause-driven principle, and the fellow who treats the cause first holds the central management principle. [2]

The components and the heparin (3 marks). The blood components treat the bleeding, and the boy receives the platelet transfusion for the count under fifty times ten to the nine per litre, the fresh-frozen plasma at ten to fifteen millilitres per kilogram for the prolonged clotting times, and the cryoprecipitate or the fibrinogen concentrate to hold the fibrinogen over one gram per litre. Because the picture is thrombosis-dominated, with the purpura fulminans and the digital ischaemia, the boy also receives the therapeutic unfractionated heparin, titrated to the partial thromboplastin time, alongside the urgent plastic-surgical review for the skin and the limb salvage. The components and the heparin support the child while the cause treatment resolves the DIC. [2][3]

Question 2 (10 marks)

Explain how the management would change for a different trigger, and critically appraise the scoring systems and the anticoagulant evidence. [2]

A full-mark answer reproduces the acute promyelocytic leukaemia scenario, the sepsis-induced coagulopathy score, and the anticoagulant evidence. [4]

The acute promyelocytic leukaemia scenario (3 marks). If the trigger were the acute promyelocytic leukaemia rather than the sepsis, the management shifts in one critical way: the all-trans retinoic acid is started immediately, the moment the diagnosis is suspected, and not delayed for the confirmatory marrow. The acute promyelocytic leukaemia releases the procoagulant granules from the leukaemic blasts, and the DIC is present at the diagnosis in the majority of children, with the early fatal haemorrhage the chief cause of the early death. The components and the heparin continue as for the sepsis picture, but the all-trans retinoic acid is the measure that prevents the catastrophic early bleed. The fellow who delays the all-trans retinoic acid for the marrow result exposes the child to the early death. [3]

The sepsis-induced coagulopathy score (3 marks). The sepsis-induced coagulopathy score of Iba and colleagues sits upstream of the ISTH score. It combines the platelet count, the international normalised ratio, and the organ-dysfunction score, and a total of four points or more in a child with sepsis defines the sepsis-induced coagulopathy. The follow-up work showed that the sepsis-induced coagulopathy state precedes the ISTH overt-DIC state and predicts the high mortality, so it gives the fellow the upstream marker that warns before the overt disease. The two scores are stages on a continuum, and the fellow who reads both holds the whole course. [4]

The anticoagulant evidence (4 marks). The anticoagulant therapy is reserved for the thrombosis-dominated picture, and the routine heparin for the bleeding-dominated disseminated intravascular coagulation is not supported by the evidence. The antithrombin concentrate, given to replace the consumed antithrombin, has not shown the survival benefit, and it is not recommended routinely. The recombinant activated protein C, the drotrecogin alfa, was withdrawn in 2011 after the PROWESS-SHOCK trial showed no benefit, and it is no longer available. The recombinant soluble thrombomodulin, the ART-123 that replaces the missing endothelial brake, is the newer agent, and the meta-analysis suggested a benefit in the sepsis-associated coagulopathy with the overt DIC, though the paediatric data remain limited. The fellow who states that the cause treatment is the definitive treatment, and that the components and the heparin are the supportive measures, has the evidence-based answer. [2][4]