New content quiz January 2015

The expiratory hold maneouvre measures the degree of auto-PEEP. Expiration is held at the end of expiration by occluding the expiratory port which allows equilibration of the alveolar and airway opening pressures. Auto-PEEP = the airway pressure – applied PEEP. (link)

The recommended initial ventilator settings for a newborn is TV 20mL/ 50 breaths/min. (link)

The recommended initial ventilator settings for an average sized 1 year old to achieve normal ventilation are TV 60mL/ 35 breaths/min (link).

The spider is a White tailed spider. (link)

The photo shows erythema nodosum. (link)

There is little high quality data about patients with PICC lines that are thrombosed but not obstructed. Management options include: Systemic anticoagulation for at least 6 weeks as for lower limb DVT; or insertion of an SVC filter for patients where anti-coagulation is contraindicated. It is unclear if catheter removal is required as most patients still require the catheter, so removal requires re-insertion of another catheter in the contralateral arm. Patients with haematological malignancies do not appear to have better outcomes with catheter removal, compared to systemic anti-coagulation alone. As there is  risk of serious pulmonary embolism if the catheter is removed when there is an adherent large thrombus, catheter removal after 3-5 days of anti-coagulation is an option for large thrombosis. (link)

The incidence of acute coronary occlusion in survivors of a PEA arrest is approximately 30%. (link)

The recommended dose of tPA in cardiac arrest is 50mg IV bolus, repeated at 15 minutes if there is no ROSC. (link)

The E-liquids and aerosols used in e cigarettes appear to have toxicant levels much lower than those from tobacco smoke and have a very low carcinogen content. E cigarettes have a minimal risk for nicotine poisoning when used as intended and the humectants in e-cigarettes seem safe for inhalation. E-cigarettes can reduce smoking urges and may help motivated smokers to quit. (link)

US has higher sensitivity (> 90% vs 75%)  than supine CXR with a similar specificity (> 95%). It is approximately 5% more  accurate overall than combined clinical examination and chest radiography. (link)

Common clinical features of Ebola infection are: a non-specific febrile prodrome of < 1 week; fever > 38C; hypotension; relative bradycardia; conjunctivitis; pharyngitis with dysphagia; cutaneous flushing or maculopapular rash; vomiting and diarrhoea (which may be bloody); arthralgia; hiccough (usually in the pre-terminal phase). Lymphadenopathy and hepatomegaly are rare so other diagnoses should be considered. (link)

A falling platelet count with marked lymphopenia can be seen in the initial stages of infection but is not diagnostic. A neutrophil leucocytosis occurs in the later stages in patients who eventually recover, along with normalisation of thrombocytopaenia. There is usually coagulation factor depletion with an elevated INR / APTT and DIC. AST rises more than ALT in Ebola with a  high AST/ALT ratio indicating poor prognosis. Jaundice is rare in Ebola as are pulmonary infiltrates on CXR. (link)

As blood PCR may be negative early in the course of the disease, a repeat PCR is required at 48 hours. Despite the low risk of transmission to others from ‘dry’ Ebola, due to the high lethality of the disease, ongoing strict isolation in hospital is required. Negative blood tests or PCR from throat or urine samples are not currently considered as ruling out the disease. (link)

It is not essential to have ABO and Rh compatibility for platelet transfusion, although this is ideal. Without compatibility, platelet survival may be reduced, however haemolysis is rare. RhD sensitisation may occur so consider giving prophylactic RhD immunoglobulin when RhD positive platelets are transfused into a RhD negative recipient, particularly in premenopausal females. A filter is not required for the transfusion of platelets. (link)

The pattern of abnormalities is most characteristic of anaemia of chronic disease. Fe deficiency anaemia would be expected to have an elevated transferrin. Sideroblastic anaemia would not be expected to have low serum iron or transferrin. Thalassaemia minor usually has a decreased MCV/Hb ratio. (link)

An anaemia with an MCV elevated to such an extent is usually only caused by either Vitamin B12 of folate deficiency. (link)

Both the radial nerve and the radial artery usually lie between EPL and extensor indicis, however the radial artery is more superficial, so is most likely to have been injured by the mechanism described. EPB is more radial to EPL and extensor digitorum is more ulnar in location. (link)

Brachioradialis is the most likely muscle involved as FDS and Palmaris longus are more medial. Supinator is located on the dorsal aspect of the forearm. (link)

The superior sagittal sinus usually drains into the straight sinus. (link)

Pneumatic tube systems can transport most types of specimens to the laboratory, however blood culture bottles require special protection to prevent breakage and blood gas samples need to be sent in a sealed container to prevent changes in the ambient pressure altering partial pressure values. Potentially infective samples from serious transmissible diseases (e.g. Ebola) should not be sent through a pneumatic tube system. (link)