 Welcome to emergency medicine video on asthma. In this part we'll discuss the presentation and investigations. Asthma is a chronic inflammation of the airways. The edema in the airway and bronchoconstriction is what give asthma patients the most trouble. The airway edema and bronchoconstriction causes airflow obstruction. As a result, patients is unable to get rid of their CO2 and also unable to oxygenate. Patients can die quickly from respiratory arrest. Therefore we must know how to manage asthma in the emergency department. Usually patients who have asthma will know that they have a history. It's important for us to know what triggers their asthma exacerbation. Allogens exposure is an important cause for asthma exacerbation. So is smoking. It can also be triggered by a viral upper respiratory tract infection. In the emergency department we are much more worried about the patients who have severe exacerbations. On history there are a few items we look for to let us predict whether the patient will likely have a severe exacerbation or not. They include previous exacerbation that needs ICU stay or intubations. Multiple hospital admissions or known poor baseline function. How do patients with asthma exacerbation present? Let's first talk about symptoms. Asthma patients usually present with shortness of breath and chest tightness. It is usually worse on exertion. They may describe hearing wheezes. They may try to use their puffers more often. There are various signs we need to look for on examining the patient. We start by looking at the patient's general appearance. In mild exacerbation patients will be lying down comfortably. In patients with moderate exacerbation they will now start to sit up. In severe exacerbation they now assume a tripoding position where they use their hand to push against their thighs for support. We now look at the level of consciousness. In mild exacerbation and moderate exacerbation their level of consciousness should be normal. Whereas in patients with severe asthma exacerbation they might be confused or has decreased level of consciousness. We next look at color. Patients with mild exacerbation will not be cyanotic. Whereas the patient who has severe exacerbation will be cyanotic. The patient with severe exacerbation will also be diaphoretic. In terms of vital signs patients with mild exacerbation might be slightly tachypnic and tachycardic. Their oxygen saturation should be normal. As they get sicker they become more tachycardic and more tachypnic. They start to drop their sats. In severe patients they can be either extremely tachycardic or braticardic. They are hypotensive and the oxygen saturation drops even lower. This is how we try to stratify the patient on general examination. How about on respiratory exam? What should a patient with mild exacerbation sound like? Those patients should be able to talk to you in full sentences. They have tachypnea but there should be no in-drawing. They should have bilateral air entry even though they might be decreased. They will have wheezes. In patients with moderate exacerbation they now have 3-4 word dyspnea. They might have in-drawing. They can be seen in the intercostal area and the supra-colivicular area. They may also have a tracheotug. They have loud wheezes and decreased air entry. In severe asthma patient might only be able to say one word at a time. There is more in-drawing in tracheotugging. They may also have abdominal breathing. On auscultation you might hear a very quiet chest with little air entry and no wheezes. Since there is no air going through the airway to produce the wheezes. Let's move on to investigations. Chest x-ray should be done in patients that we suspect are in ammonia. In patients who have a good history of a trigger by an allergen or a viral URTI, the chest x-ray is not necessary. The chest x-ray will be helpful in patients if we were suspecting other conditions such as pneumothorax or pneumomedia stynum. Blood work has no role in the patient with a routine exacerbation. EKG can be done in patients if you are suspecting of any myocardial ischemia. One specific investigation we do in patients with asthma is an FEV1. An FEV1 is a bedside test that can only be done in alert patients. It measures patients' forced expiratory volume in one second. What do we do with this information? Based on patients' age, size, and gender, we can look up on a table to see what their expected FEV1 should be. We then compare it as a percentage with the patient's measured FEV1. We use that percentage to risk stratified patients. Patients with a mild exacerbation will have 50-70% of their expected FEV1. In patients with moderate exacerbation, the number is about 25-50%. And in severe exacerbation, the FEV1 is less than 25% of the expected. We use this information in conjunction with our clinical examination to determine how sick the patient is. In summary, we discuss the presentation of patients with asthma. We discuss different ways to decide on whether the patient is having a mild, moderate, or severe exacerbations. They include general appearances, respiratory exam, and FEV1 measurements. In the next segment, we will discuss the treatment for patients with asthma exacerbation. We hope you find this useful. Thank you for watching.