DVT and Pulmonary Embolism MCQs

A pulmonary thromboembolism results in areas of the lung that are ventilated, but not perfused, yielding V/Q ratios of infinity and an increase in alveolar deadspace. When the V/Q ratio equals infinite, the PAO2 of the affected alveoli will be the same as that in the humidified inspired air because atmospheric air enters the alveoli via the process of ventilation but no gas exchange takes place because the alveoli are not perfused. Areas of the lung that are perfused but not ventilated constitute areas of shunting (venous admixture), characterized as a V/Q ratio equal to 0, and having PAO2 values that equilibrate with the mixed venous blood. Reference: Kasper et al., pp 282, 1561. Levitzky, pp 114-117. Stead, pp 272-273.

Causes of small pupils include: Horner's syndrome Old age Pontine haemorrhage Argyll Robertson pupil Drugs and poisons (opiates, organophosphates). Causes of dilated pupils include: Holmes-Adie (myotonic) pupil Third nerve palsy Drugs and poisons (atropine, cobalt [CO], ethylene glycol). Reference: Harrison's Principles of Internal Medicine, 21 st ed, Ch: 32, Pg: 216

Haemoptysis can be caused by pulmonary embolism, tuberculous infection, aspergilloma, bronchial carcinoma, good pasture's syndrome and Wegener's granulomatosis. Interstitial lung disease presents with dry cough along with progressive dyspnoea. Asthma presents with episodic breathlessness and cough in exposure to cold or allergens. Goitre presents as neck swelling; if large, it may compress the trachea causing stridor and breathlessness; retrosternal extension causes venous congestion due to compression of superior vena cava. Reference: Harrison's Principles of Internal Medicine, 21 st ed, Ch: 39, Pg:270-272

Extrinsic Allergic Alveolitis is type IV hypersensitivity. There is no eosinophilia, IgG and lymphocytes are involved in immune response. Antigens of micropolyspora faeni and thermoactinomyces are 0.5-5 microns. Assaying for IgG antibodies against specific antigens, either through precipitin testing or direct serum measurement, can be a useful adjunct in the diagnosis of HP High-resolution computed tomography (HRCT) is a common component in the diagnostic workup; In subacute forms of the disease, ground-glass airspace opacities are characteristic, as is the presence of centrilobular nodules. Expiratory images may show areas of air trapping that are likely caused by involvement of the small airways BAL shows a lymphocytic predominance with a greater proportion of CD8 positive T cells . Reference: Harrison's Principles of Internal Medicine, 21 st ed, Ch: 288, Pg: 2161

Cardiovascular disease is the leading cause of morbidity and mortality in patients with CKD at all the stages. Hypertension and dyslipidemia are the risk factors that accelerate atherosclerosis in CKD. Reference: Harrison's Principles of Internal Medicine, 21 st edition, Ch:311, Pg:2315

Recurrent oral ulceration is the commonest manifestation and the presenting feature in Behcet's disease. Diagnosis of Behcet’s disease requires - Recurrent oral ulcers plus two of the following four clinical manifestations: Recurrent genital ulcers – cause scarring Skin lesions - Erythema nodosum, pseudofolliculitis, papulopastular or acneiform nodules Eye lesions - Anterior or posterior uveitis, corneal ulceration, conjunctivitis, papillitis, Positive pathergy test Vasculitis, pustules and subcutaneous nodules can also occur. Vascular thrombosis occurs in about 10% of patients. Reference: Harrison's Principles of Internal Medicine 21 st ed, Ch: 364, Pg: 2818

The overall diagnosis is Behcet's syndrome. There is a thrombotic tendency (venous>>arterial), hence the likely cause of a DVT. Reference: Harrison’s Principles of Internal Medicine 21 st edition Ch:364 Pg:2817

Pneumoconiosis is not associated with clubbing. Pulmonary embolism causes right heart strain and may present with RBBB Rv strain and Ischemia in ECG. Lung Carcinoids are rarely associated with pleural effusion. Bronchopulmonary aspergillosis is associated with wheezing. Reference : Harrison's Principles of Internal Medicine, 21 st Ed, Ch: Ch: 288, Pg: 2165