New content quiz September 2013

The ptosis of Horner’s syndrome is reverse ptosis that affects the lower lid more than the upper. It is usually mild (if severe, think of a CN III lesion), worse when the patient is fatigued and associated with enopthalmos. (Link)

Holmes Adie syndrome is a postganglionic parasympathetic denervation affecting the pupil of the eye and the autonomic nervous system. It is most common in young women and associated with Sjogren’s syndrome and migraine. Examination reveals an initially unilateral dilated pupil that usually progresses to be bilateral. it constricts slowly to bright light and may be incomplete. It is slow to dilate again after light removed (tonic pupil) and has decreased or normal accommodation. Slit lamp examination may reveal iris sector palsy or vermiform iris movements.
Decreased tendon reflexes (usually in the Achilles tendon) are usually permanent, however may not be present at the time of presentation for mydriasis. Excessive sweating may also be present. (Link)

A Marcus Gunn pupil indicates a lesion in the afferent pathway of the affected eye, usually optic neuritis or MS. It is diagnosed using the swinging light test where light is alternately shone into the left and right eyes. The normal response is equal constriction of both pupils, regardless of which eye the light is directed at. This indicates an intact direct and consensual pupillary light reflex. When an afferent pupillary defect is present, light directed into the affected eye causes only mild constriction of both pupils (due to decreased response to light from the afferent defect). Light directed into the unaffected eye causes normal constriction of both pupils (due to an intact afferent path, and an intact consensual pupillary reflex). As a result, light shone into the affected eye produces less pupillary constriction than light shone in the unaffected eye. (Link)

Eaton Lambert syndrome is caused by antibodies affecting P/Q-type voltage-gated calcium channels on the presynaptic (not post synaptic) membrane of the neuromuscular junction. It causes gradual onset proximal muscle weakness and strength may improve with repetition (unlike Myasthenia gravis that worsens). it is much less common than Myasthenia gravis. Autonomic dysfunction is present in > 90% of patients during the course of the disease, but there is usually no ptosis. Nerve conduction testing can confirm the weakness ito be due to neuromuscular junction disease and facilitation during repetitive-stimulation testing differentiates it from Myasthenia gravis. (Link)

MERS Co-V has 65% case fatality rate and is thought to be transmitted by person to person contact. It has an incubation period 5 days and 95% of infected patients have onset of symptoms by day 12. Cough and fever are present in 90% of cases, but shortness of breath is less common (50%) at time of presentation and vomiting / diarrhoea are present in 35% of cases.As of August 2013, no validated serological test is available.(Link)

False positives can occur with: alkaline urine; quaternary ammonium compounds and chlorhexidine; and menstruation or vaginal discharge. Microscopic haematuria is not a cause of proteinuria.(Link)

Medications that can (all uncommonly) cause microscopic haematuria include: antibiotics such as the aminoglycosides and extended spectrum penicillins; chemotherapeutic agents such as cyclophosphamide, vincristine of busulfan; amitriptyline; anticonvulsants chlorpromazine and amitriptyline; diuretics; and aspirin / NSAIDs. Paracetamol is not known to cause haematuria.(Link)

A non haemolysed trace corresponds to 1-2 RBCs per high powered field, which is less than the 3RBCs/HPF required to be pathological.(Link)

Venous stenosis is particularly common with artificial fistulae and usually usually occurs at the venous anastomosis site. It is characterised by a a strong pulse, a vigorous systolic thrill or high pitched systolic bruit immediately before the anastomosis. A properly functioning graft has a soft easily compressible pulse with a continuous thrill palpable (without compression) only at the arterial anastomosis. It has a low-pitched bruit, continuous in systole and diastole.(Link)

Vasopressin does not appear to improve survival compared to adrenaline. Although recommended as an alternative to adrenaline, it is not commonly used in Australasia. A July 2013 European RCT of vasopressin (20 Units) in addition to 1mg of adrenaline for each CPR cycle (3min) demonstrated an improvement in ROSC (84 vs 66%) and hospital survival with good neurological function (14 vs 5%) when used in addition to initial 40mg IV methyl prednisolone after the first CPR cycle and 300mg hydrocortisone given at 4 hours post arrest to survivors. Applicability to current EM practice is questionable as: the trial was conducted prior to the introduction of current ACLS guidelines; comprised of 85% in-hospital (non ED) arrests (75% of which had non cardiac causes for their arrest) and 90% had witnessed arrests. Thus the results are least applicable to out of hospital arrests. (Link)

Loss of rational thought is actually negatively associated with future suicide attempts within 6 months (despite being part of the SAD PERSONS index). All the other options are weakly positively associated with future suicide attempts – including age 20-45 years (i.e. the opposite to that stated as a negative risk factor by the SAD PERSONS index). (Link)

Previous self harm and depressed mood appears to be the strongest risk factor (OR 4) with serious suicidal intent (OR 2.7) being the next strongest predictor. Helplessness (OR 2.2) and a moderate risk score on the modified SAD PERSONS index (OR 1.4) are weaker predictors. (Link)

HACEK organisms include: Haemophillus (non influenzae) – parainfluenzae, haemolyticus, parahaemolyticus, (aphrophilus and paraphrophilus are now classified as Aggregatibacter sp.); Actinobacillus actinomycetemcomitans, Aggregatibacter aphrophilus; Cardiobacterium hominis; Eikenella corrodens sp.; and Kinginella kingae..They usually have a less acute onset than other organisms (esp Staph Aureus) and are not common in IV drug users as most of them are normal oropharyngeal flora. They require culturing on special media, hence are responsible for a substantial proportion of ‘culture negative’ endocarditis. (Link)

A knife as foreign body is the weakest indication – some knifes are not that sharp (ie butter knives) and if they could be inserted without problems, they should be able to be removed without any either! Features of severe local pain, perforation or significant haemorrhage require much closer evaluation and likely repair, hence the requirement for a GA. (Link)

The most common (present in > 20% of cases) are the: anterior superior oval sign (single or multiple oval, round, or pear-shaped gas bubbles projected over the liver shadow); hyperlucent liver sign (the blacker density of intraperitoneal free gas anterior to the ventral hepatic surface replacing the brightness of the hepatic shadow); subphrenic radiolucency of gas under the diaphragm; Rigler sign (both sides of the bowel wall can be visualised)
Present in 10-20% of cases are the: falciform ligament sign (free gas may outline the falciform ligament, which is seen as a linear density situated longitudinally just to the right of the midline in the upper abdomen); cupola sign (arcuate lucency overlying the lower thoracic spine and projecting caudad to the heart); football sign (large oval radiolucency in the shape of a football producing a sharp interface with the parietal peritoneum); hepatic edge sign (oblong saucer or cigar-shaped collection of free gas in the subhepatic space); triangle sign (triangular radiolucency between 3 adjoining bowel loops or 2 bowel loops and the parietal peritoneum); inverted V sign (an inverted “V” may be seen over the pelvis on the supine films caused by the 2 lateral umbilical ligaments outlined by free gas); fissure for ligament teres sign (visualisation of the extrahepatic part of ligament teres)
Present in < 5%: dolphin sign (the under surface of the long costal muscle slips of the diaphragm can be seen indenting the adjacent gas filled space in the RUQ); dodge cap sign (triangle-shaped free gas in Morrison’s pouch); urachus sign (the urachus may be seen as a thin midline linear structure in the lower abdomen from the umbilicus to the dome of the urinary bladder) (Link)