New content quiz November 2013

The Moro reflex is elicited by a sudden dropping of the baby’s head in relation to its trunk. The normal response is opening of the hands extension and abduction of the arms followed by drawing them together. The reflex first appears between 28 and 32 weeks gestation, is present in all newborns and disappears between 3 – 5 months of age. Persistence beyond 6 months of age or its absence during the first few weeks of life indicates neurologic dysfunction. (link)

A Galleazi fracture is a fracture of the mid-shaft radius with dislocation of distal radioulnar joint. The radiographic features include: shortening of the radius by ≥ 5 mm; a fracture of the ulnar styloid process;  widened distal radioulnar joint space by 2 mm; subluxation of distal radioulnar joint.

A Monteggia fracture involves the proximal third of the ulna with a dislocated radial head (anteriorly). Significant rotation of the radius and ulna (usually approximately 90 degrees) may make description of the radiographic views obtained difficult.

The radiograph demonstrates a Chauffeur’s fracture. Which is often a ‘kick back injury’ and usually not displaced. It is associated with scapholunate dissociation, trans-styloid, perilunar dislocation and a dorsal Barton’s fracture. A Barton’s fracture is a variant of a Smith’s fracture where the volar lip of the radial articular surface is involved. A Rolando’s fracture is a 3 part intra-articular fracture involving the metacarpal of the thumb, Y or T shaped in nature . (link)

Enoxaparin 1.5 mg/kg subcut once a day should not be used in patients > 100kg in weight (i.e. maximum dose 150 mg). Enoxaparin 1 mg/kg subcut bd can be used with no maximum dose. It has only recently been recognised that there should be no maximal dose. Monitoring of anti-Xa levels in patients with BMI >35 or < 20 should be considered to ensure adequate anti-coagulation. (link)

Falls are a relatively weak contra-indication as the stroke risk is higher in patients with falls and the probability of a serious outcome from each fall is usually relatively low. It has been shown that anti-coagulation is still of benefit if CHADS2 score ≥ 2 even if at high risk of falls. Anti-coagulation should be ceased if a bleeding complication following a fall has occurred.(link)

The HAS BLED score has the following components: uncontrolled Hypertension, Stroke, Bleeding history or predisposition; Labile INR; Elderly >65 years; Drugs (aspirin, NSAIDs/alcohol abuse) concomitantly. According to it’s inventors, ‘elderly’ age starts at 65 years, not 75 years. (link)

Heart failure, LV dysfunction or diabetes mellitus are risk factors for anti-coagulation related bleeding, but are not included in the HAS BLED score, (link)

The bleeding risk from warfarin is about 10% / year, with about 25% of these serious, and 0.25% overall, fatal (usually from ICH). About 50% of cases occur despite the INR being within the target range. The highest risk of bleeding is in the first 3 months of therapy, but also increases as the patient ages. (link)

Although 100% sensitive, it is only about 15% specific, so is not particularly helpful in identifying patients who do not need investigation.

There is an increase in the epiphyseal plate width with distal metaphyseal irregularity of a Salter Harris type I injury. There is also a fracture of the ulnar styloid tip. A Type V injury is a crush injury to the epiphysis with narrowing of the epiphysis the cardinal sign. (link)

As well as degenerative changes, the radiograph demonstrates calcification of the medial meniscus, typical of pseudogout. The joint aspirate revealed the presence of positively birefringent crystals. There are no tophi to suggest gout or bony erosion/periosteal reaction to suggest osteomyelitis. There is no soft tissue swelling, juxtaarticular osteoporosis, bony erosions at the joint margins, or subchondral bone destruction to suggest Rheumatoid arthritis. (link)

Proven pneumococcal pneumonia only requires standard precautions as person-to-person transmission risk is low. Unfortunately the exact pathogen causing respiratory infections in most ED patients is unknown, so a higher level of isolation precaution is usually initially required. (link)

Zoster that is isolated, in an immunocompetent individual, and where the lesions can be covered, only requires standard precautions. Disseminated Zoster requires strict (airborne) isolation. (link)

In this woman it is likely that CPAP will provide the greatest benefit whilst she is in the ED. If her PaO2 can be increased from 55mmHg to 95mmHg, then her SpO2 will increase by 10-15%. This is likely to improve cardiac output as the heart has a high oxygen extraction ratio. GTN may increase cardiac output by a similar amount, however afterload does not appear to be particularly high in this case and reduced coronary flow is likely if hypotension occurs. Blood transfusion of 2 units would increased [Hb] by 20%, however its immediate effect on the oxygen content of the blood would be much less than this as chronic anaemia induced changes in the Hb-O2 curve and reduces blood viscosity. Also, in the setting of fluid overload, additional volume expansion is likely to further reduce cardiac output. Inotropes are unlikely to produce increases in cardiac output of >10%  in the best of circumstances, and will do little/nothing to increase cardiac output in a hypoxic heart. (link)

The image demonstrates an os trigonum. It is smooth and well corticated, unlike a fracture. The epiphysis in this area fuses by 9 – 14 years, so would not be seen in a 19 year old. The fabella is a sesamoid bone in the head of the biceps femoris near the head of the fibula. (link)