New content quiz October 2014

When required, crystalloids should be used in preference to colloids (especially starch solutions) as starch and gelatin containing solutions are associated with increased mortality and interfere with clot formation. Albumin solutions appear to cross the blood brain barrier and may increase cerebral oedema in patients with TBI. Despite their limitations crystalloids are the fluid of choice in the initial management of trauma.(link) 

Transfusion in a ratio of 5 Units packed cells: 5 Units FFP : 1 adult dose platelets is the same as a 1:1:1 ratio in countries that do not have adult dose platelets (1 adult dose platelets = 5 units of platelets) is appropriate if thromboelastography is not available. A ratio of 10:5:1 is estimated to increase mortality by 5%. A thromboelastography guided approach to clotting factor and antifibrinolytic therapy is another reasonable approach, if immediately available. Transfusion therapy guided by results laboratory testing of INR/APPT and platelet counts is inappropriate due to the length of time for these results to be known and as they do not correlate well with the severity of coagulopathy following trauma. (Link)

The usual management priorities in trauma induced coagulopathy are (from first to last): direct haemorrhage control; prevention or treatment of hypothermia, acidosis and hypocalcaemia; reversal of anticoagulantion (if present); inhibition of fibrinolysis (TXA); ensuring adequate fibrinogen (cryoprecipitate); factor II, IX, X replacement with PCC; platelet transfusion; replacement of factors VII/ XIII/VIII. (link)

Decompressive craniectomy improves outcome if performed within 24 hours in children with severe traumatic brain injury and severe cerebral oedema. It also probably reduces mortality and severe disability in adults if performed within 6 hours of injury. It is likely to be of much less benefit if coagulopathy present. Is indicated if ICP persistently > 25mmHg despite medical intervention within 12 -18 hrs of TBI. (link)

The most common symptoms of panic attacks are lightheadedness, paraesthesia, chest tightness, sensation of palpitations,difficulty breathing and choking/difficulty swallowing. Less common symptoms include flushes or sensation of chills, nausea or abdominal distress. True abdominal pain is very uncommon and not usually constant, so should initiate a search for an alternative cause. (link)

DVT can occur in 0.6 – 6% of patients with lower limb injuries treated in the ED with rates of up to 15% reported if immobilised in a cast for > 4 weeks, however the rates of symptomatic DVT or VTE are much lower (0.6%) than those reported from studies using routine imaging for detection. Rates of PE are so low as to make thromboprophylaxis in all patients more likely to be harmful and symptomatic above knee DVT occurs in approximately 0.2% of all injury types treated as an outpatients so only patients with a major bony injury and age > 50 years should be considered for VTE prophylaxis. (link)

Non bleeding retrohepatic caval injuries in the stable patient should be left alone- exploration usually causes serious haemorrhage that may not be able to be controlled. Angiographic embolisation may be considered for lower grade injuries with ongoing bleeding. Surgery is usually a better option if estimated blood loss from the liver injury is > 500-700mL. Non interventional management usually requires all of the following: a contained haematoma; a unilobular fracture, the absence of devascularised segments (i.e. enhancing on CT); only small amount of intraperitoneal blood. (link)

The Prothrombin time (PT) measures the effectiveness of the extrinsic clotting pathway. It is particularly sensitive to low levels of fibrinogen and may be prolonged in hypoalbuminaemia. Differences in laboratory techniques results in a variety of normal and therapeutic ranges so results are expressed as an INR when the test is used to monitor oral anticoagulant therapy. The normal range is usually 11-15 seconds. (link)

The primary role of the ecarin clotting time is to measure the activity of direct thrombin inhibitors (e.g. dabigatran). It is relatively unaffected by low thrombin and fibrinogen levels. It is difficult to perform so has limited use for ED practice as results usually take too long to become available. The normal range is 22-29 sec.

Dabigatran is a direct thrombin inhibitor, so has no effect on the anti factor Xa assay. Although the assay is primarily used to monitor therapy with LMWH, it is affected by unfractionated heparin. (link)

EXTEM – measures the activation of the extrinsic pathway initiated by tissue factor. FIBTEM
is a qualitative measure of fibrinogen status. APTEM measures the degree of fibrinolysis. INTEM
measures the activity of the intrinsic pathway. ECATEM measures the effects of direct Xa inhibitors. HEPTEM measures the effects of heparin. (link)