A British Society for Haematology Guideline: Diagnosis and management of thrombotic thrombocytopenic purpura and thrombotic microangiopathies

The objective of this guideline is to provide healthcare professionals with clear, up-to-date and practical guidance on the management of thrombotic thrombocytopenic purpura (TTP) and related thrombotic microangiopathies (TMAs), including complement-mediated haemolytic uraemic syndrome (CM HUS); these are defined by thrombocytopenia, microangiopathic haemolytic anaemia (MAHA) and small vessel thrombosis. Within England, all TTP cases should be managed within designated regional centres as per NHSE commissioning for highly specialised services.

Unclassified bleeding disorders: outcome of haemostatic challenges following tranexamic acid and/or desmopressin

INTRODUCTION

In a minority of patients with a significant bleeding history no cause is found despite extensive testing and we diagnose such cases as unclassified bleeding disorders (UBD). UBDs may have diverse underlying causes and currently no standard management strategy exists in the event of a haemorrhage or to cover surgery.

AIM

To document the clinical characteristics and response to treatment of UBDs.

METHODS

We performed a retrospective chart review of all patients with UBDs who had an invasive procedure at our centre between 1998 and 2014.

RESULTS

The commonest symptoms were menorrhagia (89%) and bleeding at the time of surgery (88%) or dental extraction (85%). A total of 33 patients underwent 78 minor and major haemostatic challenges. Haemostatic cover was provided in 28 procedures with tranexamic acid alone, two with desmopressin and 45 with both agents in combination. A successful haemostatic outcome was observed in 70/78 (90%) cases. No patient required additional surgical intervention to achieve haemostasis, but one patient required a platelet transfusion to control postoperative bleeding.

CONCLUSIONS

This is the first study to report on the investigation and treatment of UBD. Future studies are needed to further our understanding of the bleeding phenotype and identify any underlying causes.

The use of fibrinogen concentrate to correct hypofibrinogenaemia rapidly during obstetric haemorrhage

Haemorrhage is a common complication of childbirth with 0.65% of deliveries associated with significant (>1500 mL) peripartum blood loss. Hypofibrinogenaemia secondary to dilutional and consumptive coagulopathies can be challenging to correct quickly with conventional blood and plasma therapy. Fibrinogen concentrate offers rapid restoration of fibrinogen levels with a small volume infusion and minimal preparation time. It is effective in treating patients with congenital hypofibrinogenaemia, but there are few reports of its use in association with continuing obstetric haemorrhage. Six cases of obstetric haemorrhage, associated with hypofibrinogenaemia, treated with fibrinogen concentrate in conjunction with platelets, fresh frozen plasma, packed red blood cells, uterotonics and obstetric intervention are described. In all cases, laboratory assessed coagulation was rapidly normalised and severe haemorrhage improved. These cases suggest that fibrinogen concentrate may be an effective addition to conventional treatments for obstetric haemorrhage associated with hypofibrinogenaemia.

Antenatal interventions for fetomaternal alloimmune thrombocytopenia

BACKGROUND

Fetomaternal alloimmune thrombocytopenia occurs when the mother produces antibodies against a platelet alloantigen that the fetus has inherited from the father. A consequence of this can be a reduced number of platelets (thrombocytopenia) in the fetus, which can result in bleeding whilst in the womb or shortly after birth. In severe cases this bleeding may lead to long-lasting disability or death. Antenatal management of fetomaternal alloimmune thrombocytopenia centres on preventing severe thrombocytopenia in the fetus. Available management options include administration of intravenous immunoglobulins or corticosteroids to the mother or intrauterine transfusion of antigen compatible platelets to the fetus. All options are costly and need to be assessed in terms of potential risk and benefit to both the mother and an individual fetus.

OBJECTIVES

To determine the optimal antenatal treatment of fetomaternal alloimmune thrombocytopenia to prevent fetal and neonatal haemorrhage and death.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (February 2004), EMBASE (1980 to February 2004) and bibliographies of relevant publications and review articles.

SELECTION CRITERIA

Randomised controlled studies comparing any intervention, including corticosteroids with no treatment, or comparing any two interventions.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed eligibility, trial quality and extracted data.

MAIN RESULTS

One study met the inclusion criteria (54 pregnant women). This trial compared intravenous immunoglobulins plus corticosteroid (dexamethasone) with intravenous immunoglobulins alone. No significant differences were reported between the treatment and control groups, in any outcome measured: mean platelet count at birth (weighted mean difference (WMD) 14.10 x 10 9/l, 95% confidence interval (CI) -30.26 to 58.46), mean gestational age at birth (WMD -0.50 weeks, 95% CI -2.69 to 1.69), mean rise in platelet count from first to second fetal blood screen (WMD -3.50 x 10 9/l, 95% CI -24.62 to 17.62) and mean rise in platelet count from birth to first fetal blood screen (WMD 24.40 x 10 9/l (95% CI -14.17 to 62.97)). This trial had adequate methodological quality; however the method used to calculate sample size was inappropriate: therefore the power calculation was not sufficient to determine any significance in differences between the treatment groups.

AUTHORS' CONCLUSIONS

There are insufficient data from randomised controlled trials to determine the optimal antenatal management of fetomaternal alloimmune thrombocytopenia. Future trials should consider the dose of intravenous immunoglobulins, the timing of initial treatment, monitoring of response to treatment by fetal blood sampling, laboratory measures to define pregnancies with a high risk of intercranial haemorrhage, management of non-responders and long-term follow up of children.

A simple modification of the pin-prick test for the assessment of burn depth in children

The clinical assessment of burn depth can be particularly difficult in children. A new technique is described for applying the pin-prick test in children. It is simple to perform, causes no distress, and has consistently given reliable results. A personal series of 196 cases is presented, with a 95 per cent diagnostic accuracy.

Cross-facial nerve transplants: why are spontaneous smiles not restored?

The technique of cross-facial nerve transplantation (CFNT), with or without the addition of vascularised muscle, has made it possible to achieve some voluntary movement of the paralysed side of the face in patients with unrecovered facial palsy. If normal faces are studied during conversation, it can be seen that there are two types of movement of the lips--those of emotional expression and those involved in the formation of vowel sounds and labial consonants. Smiles themselves can be classified roughly according to their length of muscle contraction--the longer "definitive" smile, and the shorter "flash" smile. It is the synergistic facial movement of the unpremeditated "flash" smile and the small movements in the formation of the vowel sounds and labial consonants which fail to occur in patients reanimated by revascularised, reinnervated muscle, despite the return of voluntary contraction and resting facial tone. This study was undertaken to try to determine why these synergistic facial movements of short duration are so difficult to achieve.

Use of an abdominal rotation flap for inguinal lymph node dissection

In order to reduce the incidence of skin edge necrosis following dissection of the inguinal lymph nodes, an abdominal rotation flap has been used to help with closure. This allows excision of the most vulnerable skin, and closure without tension. Our experience in 13 groin dissections is presented, with skin edge necrosis in one patient (7.6%). This is compared with previously reported series and the reasons for the precarious blood supply to the skin following groin dissection are discussed.

The control of carotid arterial haemorrhage in head and neck surgery by balloon catheter tamponade and detachable balloon embolisation

Radical surgery in the neck is hazardous after irradiation. Rupture of the carotid artery may lead to uncontrollable haemorrhage. Reported mortality rates following this serious complication are between 18% and 50% (Heller and Strong, 1979). We describe a simple method for controlling acute carotid haemorrhage using a standard Fogarty biliary catheter, with selective detachable balloon embolisation for permanent occlusion of the carotid artery.