Understanding Bronchiolitis

hi this is tom from zero2finals.com in this video i'm going to be going through bronchiolitis and you can find written notes on this topic at zerothefinals.com bronchiolitis or in the respiratory section of the zero to finals pediatrics book so let's jump straight in bronchiolitis describes inflammation and infection in the bronchioles which are the small airways in the lungs this is usually caused by a virus and respiratory syncytial virus or rsv is the most common cause bronchiolitis is very common in winter bronchiolitis is generally considered to occur in infants under 1 years of age although it's most common in infants under 6 months it can rarely be diagnosed in children up to 2 years of age particularly in ex-premature babies who have chronic lung disease when a virus affects the airways in adults the swelling and the mucus inside the airways is proportionately so small it has a little noticeable effect on the breathing the airways in infants are very small to begin with and when there's even the slightest amount of inflammation and mucus in the airway it has a significant effect on their ability to circulate air in the alveoli and back out again so this causes harsh breast sounds wheeze and crackles that are heard when you auscultate the chest in a bronchiolitic infant essentially a small amount of inflammation and mucus collects in tiny tiny and this causes an obstruction to airflow in and out of the chest so how does it present corrusal symptoms are the typical symptoms of a viral upper respiratory tract infection with a runny or snotty nose sneezing mucus in the throat and watery eyes and this is what we describe as corridor symptoms the child will also have signs of respiratory distress which we'll talk about in more detail shortly dyspnea which is heavy labored breathing tachycnea which is fast breathing poor feeding a mild fever typically under 39 degrees celsius apneas which are episodes where the child stops breathing temporarily and when you oscar take the chest there can be wheezes and crackles so let's talk about the signs of respiratory distress and one of the fundamental things that you need to learn for pediatrics is to be able to spot the signs of respiratory distress these are a raised respiratory rate use of accessory muscles when breathing such as the sternocleidomastoid muscle in the neck the abdominal muscles and the intercostal muscles between the ribs intercostal and subcostal recessions which are where the skin between the ribs or just under the ribs sucks in with the breath nasal flaring which is when the nostrils flare out to try and get extra air in head bobbing which is where the head bobs with the breathing tracheal tugging which is where you can see the trachea in the neck sucking in with each breath cyanosis which is a blue discoloration of the skin that's due to low oxygen saturation and abnormal airway noises so a quick tom tip you should become very confident in listing and spotting the signs of respiratory distress this is very important when treating children in order to distinguish between a well child and an unwell child your examiners expect you to know all the signs of respiratory distress like the back of your hand so get good at practicing listing them and saying which signs are present and which are not let's talk about abnormal airway noises wheezing is a whistling sound that's caused by narrow airways and this is typically heard during expiration so breathing out grunting is caused by exhaling with the glottis partially closed and this is done because the child is trying to increase the positive end expiratory pressure in order to maintain airways that want to collapse strider is a high-pitched inspiratory noise that's caused by obstruction of the upper airway for example in croup let's talk about the typical course of bronchiolitis when it's caused by respiratory syncytial virus bronchiolitis usually starts as an upper respiratory tract infection with corrusal symptoms from this point around half of the babies will get better spontaneously the other half develop chest symptoms over the first one to two days following the onset of the corridor symptoms symptoms are generally at their worst on day three or four symptoms usually last seven to ten days in total and most patients will fully recover within two to three weeks children who have had bronchiolitis as infants are more likely to have viral induced wheeze during childhood let's talk about the criteria for admission most infants can be managed at home with advice about when to seek further medical attention the reasons for admission include children aged under three months or with any pre-existing health conditions such as prematurity down syndrome or cystic fibrosis consider admission if they have 50 to 75 percent or less of their normal intake of milk if they're clinically dehydrated the respiratory rate is above 70 the blood oxygen saturations are below 92 they have moderate to severe respiratory distress such as deep recessions or head bobbing there are apneas which remember are periods where the child stops breathing temporarily or if the parents are not confident in their ability to manage at home or to access medical help from home so what's the management well typically patients only require supportive management and this involves ensuring adequate intake and this could be orally via a nasogastric tube or iv fluids depending on the severity it's important to avoid over feeding as a full stomach will restrict the breathing so start with small frequent feeds and gradually increase them as the baby tolerates saline nasal drops and nasal suctioning can be helpful in order to clear the nasal secretions particularly prior to feeding supplementary oxygen may be necessary to keep the oxygen saturations above 92 percent and ventilatory support may be required there's little evidence for treatments such as nebulise saline bronchodilators steroids and antibiotics and these shouldn't be routinely used let's talk more about ventilatory support as breathing gets harder the child becomes more tired and less able to adequately ventilate their lungs they may require ventilatory support to maintain their breathing and this can be stepped up until they're adequately ventilated so the first step after just simple oxygen is to go to high flow humidified oxygen via a tight nasal cannula and this can be called evo or optiflow depending on the brand that provides the machine that does the high flow humidified oxygen this delivers air and oxygen continuously with some added pressure blown in through that tight nasal cannula that helps to oxygenate the lungs and prevent the lungs from collapsing it adds positive end expiratory pressure which is called peep to maintain the airway at the end of expiration and stop the airways from collapsing the next step is continuous positive airway pressure or cpap and this involves using a sealed nasal cannula that goes into the nose and performs in a similar way to the airvo or the optiflow but it can deliver higher and more controlled pressures the third option is intubation and ventilation and this is the final step this involves inserting an endotracheal tube into the trachea and fully controlling ventilation next let's talk about assessing ventilation capillary blood gases are useful in severe respiratory distress and in monitoring children who are having ventilatory support the most helpful signs of poor ventilation are a rising pco2 so the co2 level is going up and this shows that the airway have collapsed and are failing to clear waste carbon dioxide from the lungs and also a falling ph and this shows that carbon dioxide is building up and the baby is not able to buffer the acidosis that is caused by the excessive carbon dioxide remember carbon dioxide becomes carbonic acid and is acidic which means the blood becomes acidic if it can't be buffered this is classed as a respiratory acidosis if the baby is also hypoxic meaning they've got a low level of oxygen this is classed as a type 2 respiratory failure however remember that if you're taking a capillary blood gas that's not going to show an accurate oxygen level because you need an arterial sample to get an accurate oxygen level finally let's talk about pallivisimab pallavismab is a monoclonal antibody that targets the respiratory syncytial virus a monthly injection is given as a prevention against bronchiolitis caused by rsv it's given to high-risk babies such as ex-premature babies and those with congenital heart disease palavisimab is not a true vaccine as it does not stimulate the infant's immune system what it does is provide passive protection by circulating the body until the virus is encountered at which point it works as an antibody against the virus activating the immune system to fight off the virus the levels of these circulating antibodies will decrease over time which is why a monthly injection is required to keep the antibody levels adequate so thanks for watching i hope you found this video helpful if you did don't forget there's plenty of other resources on the zero to finals website including loads and loads of notes on various different topics that you might cover in medical school with specially made illustrations there's also a whole test section where you can find loads of questions to test your knowledge and see where you're up to in preparation for your exams there's also a blog where i share a lot of my ideas about a career in medicine and tips on how to have success as a doctor and if you want to help me out on youtube you can always leave me a thumbs up give me a comment or even subscribe to the channel so that you can find out when the next videos are coming out so i'll see you again soon

Channel: Zero To Finals

Views: 170,088

Keywords: medical, education, medicine, doctor, paediatrics, bronchiolitis, medical student, medical revision

Id: xM2U8tkZgas

Length: 12min 45sec (765 seconds)

Published: Sun Sep 27 2020