Tuesday, June 9, 2015

What Triggers An Asthma Attack

Asthma 1. Exercise-Induced asthma 1) Short-acting beta agonist used 20 min prior to exercise are sufficient to prevent symptoms and are first-line therapy. 2) Long-acting beta agonists may be used in children or athletes who engage in athletic activities throughout the day. 2. Patients with adult-onset asthma and symptoms that are worse after meals, exercise, or laying down are likely to have GERD-induced disease.(3024) * GERD can exacerbate airflow obstruction in asthmatics through inceased vagal tone, heightened bronchial reactivity, and microaspiration of gastric contents into the upper airway. (4335) 3. Aspirin-induced asthma (4065) 4. Beta-2 agonists like albuterol → driving potassium into cells → reduced serum potassium → muscle weakness, arrhythmias, and EKG changes Other common side effects of beta-2 agonists include tremor, headache and palpitations. 5. Management of asthma 1) Medications for chronic asthma (4617) The most common adverse effect of inhaled corticosteroid therapy is oropharyngeal thrush. Glucocorticoid-induced neutrophilia by increasing the bone marrow release and mobilizing the marginated neutrophil pool. 2) Management of asthma exacerbation * Indicators of severe asthma attack include normal to increased Pco2 values, speech difficulty, diaphoresis, altered sensorium, cyanosis, and “silent” lungs.(4105) * Endotracheal intubation and mechanical ventilation are indicated in patients with severe asthma unresponsive to medications who have fatigue, altered mental status, CO2 retention, worsening hypoxemia, and poor air movement on examination. (3459) 6. The 3 most common causes of chronic cough (lasting >8weeks) are upper-airway cough syndrome(postnasal drip), asthma, and GERD. (4519) * Numbers listed in this article is the question id number from Uworld Qbank. * For further information, please check out Uworld Qbank using the question id number listed in the article.

Thursday, June 4, 2015

Management of Ischemic Stroke: Alteplase(tPA), Aspirin and Warfarin

In all patients with symptoms of stroke, a head CT without contrast should be obtained as soon as possible to rule out hemorrhage, as hemorrhagic and ischemic stroke are treated differently. Once hemorrhage is ruled out, fibrinolytic therapy should be considered. Intravenous alteplase (tPA) has been shown to improve outcomes in victims of ischemic stroke when given within 3 to 4.5 hours of symptom onset. The sooner tPA is administered, the better the outcome. Antiplatelet therapy with aspirin is indicated in all victims of ischemic stroke who are not candidates for fibrinolytic therapy. Aspirin has proven benefits for both primary and secondary stroke prevention. However, it should not be used as a substitute for fibrinolytic therapy as it does not confer the same benefits for neurologic recovery. In patients who do receive fibrinolytic therapy, aspirin should be held for 24 hours. Urgent anticoagulation with heparin is not recommended for acute ischemic stroke, even when the etiology is cardioembolic, because of the increased risk for intracerebral hemorrhage. However, anticoagulation with warfarin can be started two weeks after an acute cardioembolic stroke to prevent recurrence.

Charcot-Bouchard aneurysm vs. Lacunar stroke

Both Charcot-Bouchard microaneurysms and lacunar infarcts occur as a result of hypertension: Charcot-Bouchard microaneurysms(hemorrhagic stroke): Chronic hypertension --> Formation of aneurysms of lenticulostriate vessels--> Rupture of aneurysms --> Intracerebral hemorrhage(most commonly located in basal ganglia and thalamus)-->increased intracranial pressure: Headache, altered mental status, seizures, brain herniations, coma, and death. Lacunar infarcts(ischemic stroke): Chronic hypertension--> Arteriolar sclerosis, hyaline formation--> Occlusion of sclerotic artery--> A small sized infarct occurs(most commonly located in basal ganglia and brainstem)-->lesions of contralateral STN-->hemiballismus

Wednesday, June 3, 2015

Asthma: Trigger factors and Therapy

Asthma 1. Exercise-Induced asthma 1) Short-acting beta agonist used 20 min prior to exercise are sufficient to prevent symptoms and are first-line therapy. 2) Long-acting beta agonists may be used in children or athletes who engage in athletic activities throughout the day. 2. Patients with adult-onset asthma and symptoms that are worse after meals, exercise, or laying down are likely to have GERD-induced disease.(3024) * GERD can exacerbate airflow obstruction in asthmatics through inceased vagal tone, heightened bronchial reactivity, and microaspiration of gastric contents into the upper airway. (4335) 3. Aspirin-induced asthma (4065) 4. Beta-2 agonists like albuterol → driving potassium into cells → reduced serum potassium → muscle weakness, arrhythmias, and EKG changes Other common side effects of beta-2 agonists include tremor, headache and palpitations. 5. Management of asthma 1) Medications for chronic asthma (4617) The most common adverse effect of inhaled corticosteroid therapy is oropharyngeal thrush. Glucocorticoid-induced neutrophilia by increasing the bone marrow release and mobilizing the marginated neutrophil pool. 2) Management of asthma exacerbation * Indicators of severe asthma attack include normal to increased Pco2 values, speech difficulty, diaphoresis, altered sensorium, cyanosis, and “silent” lungs.(4105) * Endotracheal intubation and mechanical ventilation are indicated in patients with severe asthma unresponsive to medications who have fatigue, altered mental status, CO2 retention, worsening hypoxemia, and poor air movement on examination. (3459) 6. The 3 most common causes of chronic cough (lasting >8weeks) are upper-airway cough syndrome(postnasal drip), asthma, and GERD. (4519) * Numbers listed in this article is the question id number from Uworld Qbank. * For further information, please check out Uworld Qbank using the question id number listed in the article.

Extremely High yield COPD pinpoints for USMLE CK

Chronic Obstructive Pulmonary Disease (COPD) 1. COPD encompasses chronic bronchitis and emphysema. Predominant emphysema—decreased vascular markings, decreased DLCO(due to alveolar destruction) Chronic bronchitis—bronchovascular markings, normal DLCO Differential diagnosis based on DLCO (4116) (Acute bronchitis is a common cause of blood-tinged sputum and is mostly viral in etiology. Observation and close clinical follow-up is the best treatment strategy for new-onset blood-tinged sputum in an afebrile patient with acute bronchitis but no significant signs of more serious disease. 4566) 2. Managemeng of acute COPD exacerbation(AEOPD)(4039): 1) Oxygen (target saturation 88%-92%) The criteria for initiating long-term oxygen therapy in COPD patients(4131) 2) Inhaled bronchodilators(eg., albuterol, ipratropium) (4667) * Inhaled anti-muscarinic agents such as ipratropium are the mainstay of symptom management in COPD. The anti-cholinergic medications may be combined with short-acting beta agonists for greater symptom relief. * Inhaled steroids+long-acting beta agonists – more severe COPD 3) Systemic glucocorticoids 4) Antibiotics Indications: * Two of 3 cardinal symptoms of AECOPD (increased dyspnea, cough, and sputum production) * Moderate-to-severe COPD exacerbation * Those requiring mechanical ventilation Commonly used antibiotics: Macrolides (eg, Azithromycin) Fluoroquinolones (eg, levofloxacin, moxifloxacin) Penicillins/beta-lactamase inhibitors (eg, amoxicillin-clavulanate) Duration of therapy 3-7 days 5) NPPV for moderate-to-severe exacerbation (If no contraindication) * Initial management of AECOPD includes inhaled short-acting bronchodilators, glucocorticoids, and antibiotics. Patients with continued symptoms despite medical management should be considered for NPPV. * Indications and Contraindications (4040) 6) Tracheal intubation * if no improvement with NPPV * if NPPV is contraindicated 3. Asthma Vs. COPD (4017) 1) Inhaled corticosteroids--> Asthma Long-acting anticholinergic inhaler →COPD 2) Most effective test to differentiate asthma and COPD: Bronchodilator (albuterol) →>12% increase in FEV1(resotration of normal airflow)-->Asthma → partial resersibility-->COPD 4. Secondary pneumothorax should be suspected in COPD patients presenting with catastrophic worsening of their respiratory symptoms and is usually due to dilated alveolar blebs that rupture air into the pleural space. 5. Digital clubbing * COPD alone does not cause digital clubbing, and presence of clubbing in patients with COPD should prompt a search for occult malignancy. * Conditions commonly associated with digital clubbing (4521) 6. COPD is characterized by FEV1/FVC<0.7, decreased VC, increased total lung capacity, functional residual capacity, and residual volume

Monday, June 1, 2015

Classification of Erectile Dysfunction: organic versus psychological

Erectile dysfunction(ED) is the consistent inability to maintain an erection with enough rigidity to allow sexual intercourse. Incidence is age-related. ED is classified as organic or functional(psychological). With the latter, the patient has normal nocturnal and morning erections and can have normal erections with masturbation. With the organic cause, there are 2 different manifestations: loss of libido and loss of erections. Patients often present either of the two manifestation or both. A loss of libido may indicate androgen deficiency from either hypothalamic, pituitary, or testicular disease. The site may be localized with serum testosterone and gonadotropin levels. Loss of erections, however, is often a result of arterial, venous, neurogenic, or psychogenic problems. If morning erections occur, an organic cause is unlikely. The history also must search for other medical conditions and medications that the patient may be taking. Centrally acting sympatholytics (e.g., methyldopa) can cause ED, use of beta-blockers and spironolactone can result in loss of libido.