 Hi and welcome to nursing school explain and this video on acute respiratory failure. If you haven't already done so, I highly recommend watching my video on respiratory terms and physiology that goes a little bit more into the explanatory terms that you'll need to really understand these more critical care videos so that you can follow along with the physiology and what's happening inside the body and the physiological mechanisms. So when we talk about acute respiratory failure, we always have to distinguish between two sides or two causes. So the number one cause or one of the causes is hypoxemic respiratory failure meaning that there is low oxygen in the blood and again inadequate oxygenation that is usually evident by a P802 of less than 60 when the patient is receiving O2 greater at greater than 60. Remember that room air has 21% of oxygen so this patient is in a significant amount of supplemental oxygen yet they still have a low P802. The other cause can be hypercaptic respiratory failure which now applies to the ventilatory failure so this is more of the movement of the air in and out of the chest and so we'll look at the differences here. You can see the hypochapnics classified in red where the hypoxemic here is blue such as the patient is blue cyanotic is the hypoxemic right up here. We're down here. Diagnostics and treatments are pretty much the same so they all apply for both. So let's look at hypoxemic respiratory failure. So causes for that can usually be due to respiratory issues or cardiac issues and respiratory issues that cause acute respiratory failure. Number one is probably ARDS acute respiratory distress syndrome which has in itself a lot of underlying causes and please watch the separate video on that so that you can get more familiar and distinguish here how that leads to acute respiratory failure. Certainly a significant or a bad pneumonia can lead to respiratory failure as well as smoke inhalation. A massive pulmonary embolus where now the blood flow to the lungs is impaired and we don't have enough oxygen circulating to the lungs that can be oxygenated and so now we have decreased or inadequate oxygenation and then another causes pulmonary artery laceration or massive hemorrhage in the thorax such as can occur from a massive chest trauma for example. So cardiac causes can be an anatomic shunt such as a ventricular septal defect and remember that that is an abnormal opening in the ventricular septum where now there's blood recirculating and it not every drop of blood might actually make its way to the lungs and therefore we have overall inadequate oxygenation. Shock certainly can also lead to hypoxemic respiratory failure as well as cardiogenic pulmonary edema so anything that really causes congestion of the alveoli and really the three that mostly apply here are ARDS pneumonia and this cardiogenic pulmonary edema where we have the alveoli that are just really drowning in fluid that are not able to now perform the gas exchange as normal. Now patients with hypoxemic respiratory failure will typically be short of breath as you can imagine if you have inadequate oxygen in your system they will have an increase in respiratory rate and they might have increased work of breathing and so we can see that with use of accessory muscles maybe some intercostal retraction some abdominal breathing in children sometimes we can see nasal flaring as well as tracheal tugging or even supraclavicular retractions and children as well as adults can get acute respiratory failure depending on the underlying cause. Now there might be paradoxical chest movement if we've had major trauma to the chest and then because we have not enough oxygenation to the body also the oxygen will shunt away from the skin resulting in pale colondyphoretic skin and then later on the patient can become cyanotic right so hopefully we'll detect that something is going on with this patient when they're having these milder skin signs before they become cyanotic and then we've already talked about over here so the paO2 is less than 60 which corresponds to about oxygen saturation of 80 so it will be less than that. Now whenever we don't get enough oxygen we also need to think about perfusion to the brain so signs and symptoms here will be agitation or also level of consciousness because the brain is just not being perfused and eventually the patient might be combative because their brain is just being hypoperfused. Now with this kind of air hunger and inadequate oxygenation the body's compensatory mechanism will be an increase in heart rate and blood pressure to kind of get the blood flowing and the oxygenation to where it needs to be but later on they might end up hypotensive so cyanosis and hypotension are late signs of hypoxemic respiratory failure. So let's look at the counterpart now on the other side here of this hypercapnic respiratory failure that is mostly like I said before ventilatory failure and this can be evidenced by respiratory acidosis which is characterized by a paCO2 greater than 45 and a pH less than 7.35 so signs of respiratory acidosis and we can have again respiratory causes of this hypercapnic respiratory failure and the one that really comes to mind with CO2 retention is COPD that's where the underlying cause for the disease process but also patients with asthma or cystic fibrosis can retain CO2 that then leads to this hypercapnic ventilatory failure. Now we also have to consider central nervous system causes so patients who overdose typically have a decreased respiratory drive which results in a decreased respiratory rate therefore the CO2 in their system will build up and now we have this hypercapnic state and then remember that the brain really is the regulatory center of the breathing specifically the brain stem so if there's now trauma or maybe a tumor in the brain stem or any or severe head injury that puts pressure on these control centers in the brain the patient might end up in hypercapnic respiratory failure and spinal cord injuries can be the cause of that as well. Now chest wall remember that certain principles apply to the normal movement of air in and out of the chest for the oxygenation so now if the chest wall cannot move and the diaphragm cannot contract or the chest wall is not compliant we might have hypercapnic respiratory failure so again major trauma such as a flayal chest which is a segment of multiple ribs being broken that causes this kind of paradoxical test movement and then severe obesity so the patient has all this extra radicals tissue around their torso and also the abdomen that's going to be extra hard to get the air in and the patients might end up retaining CO2 ending up in this hypercapnic respiratory state and then certain neuromuscular conditions can also cause hypercapnic respiratory failure and these also include basically a almost like a paralyzed state of the respiratory muscles that then don't allow for adequate oxygenation and hypoventilation which then end up in this hypercapnic state and conditions are myosinogratis, ALS, Guillain-Barre, polio as well as multiple sclerosis. Signs and symptoms for this hypercapnic respiratory failure include again shortness of breath and then these next two really are typical of anybody with COPD also asthma we can we can really classify for those two with exacerbations which is the typical tripod positioning and personal breathing that we see in patients that have respiratory distress because of those diseases now also their heart rate and blood pressure will go up because the body is trying to compensate and then this increased blood pressure might also be evident by finding bounding pulses now most definitely the respiratory rate is going to be decreased because remember we said OD and all these things that lead to this buildup of CO2 are caused by hypoventilation and also decrease in tidal volume so that's the volume of air that the patient takes in with every breath. Again the patient might be having central nervous system symptoms such as a headache or agitation, altered level of consciousness and then somnolence so the lack of O2 but more so the buildup of CO2 will make the patient somnolent as well as can cause decreased deep tendon reflexes. So the diagnostic tests for any of these causes of respiratory failure are pretty much to say we will want to take a look at the patients chest by means of a chest x-ray certainly arterial blood gases will be important because we want to know their P02, their PAC02 and their pH. We would want to know basic labs such as CBCC and P as well as a urinalysis to check the kidney perfusion and see how they are overall hydrated as well as EKG because we know that the respiratory and cardiac system are so closely related and respiratory causes can lead to dysrhythmias. We want to collect the blood or sputum culture if we're suspecting infectious causes such as pneumonia and then if we want to take a closer look at their lung physiology and structure maybe a CT scan or VQ which is the ventilation and perfusion scan that's a specialized scan to take a closer look at the lungs. And then for treatment so in either case we want to give the patient O2 because they are in respiratory failure they are struggling to breathe. And typically the goal is to maintain an O2 sat of 90% or PA02 of 55 to 60 and we can achieve that by any means possible and this might be by a simple administration of a nasal cannula or a venturi mask that lets us regulate the exact percentage of the patient the exact percentage of oxygen that the patient is receiving. We might the patient by the positive pressure ventilation such as a bipap machine or they might need an endotracheal tube intubation. So whatever depending on how significant the patient's respiratory failure is depends on whatever means of oxygen delivery we're going to have to initiate. And then certainly we need to mobilize secretions right if there's a lot of congestion in the lungs that prevents this gas exchange the air from moving in the CO2 from being expelled we want to get these secretions out and this can certainly be done by frequent positioning you've probably heard of prone positioning in patients with ARDS and the acute respiratory failure that we see now in the ICUs with our COVID patients as well as humidified oxygen adequate hydration and then also maybe some chest physiotherapy as well as frequent sectioning if there's a lot of congestion such as patients with asthma COPD cystic fibrosis and or pneumonia can have. Now medications used in the treatment of acute respiratory failure are bronchodilators specifically short acting beta adrenergic agonists that just help open up the lungs to allow for easier airflow. We want to decrease the inflammation we know that COPD asthma are inflammatory conditions as well as ARDS causes this massive cytokine storm all these inflammatory molecules to come to the to the help really by really the detriment of the patient's lungs as well as pneumonia and then we want to decrease the congestion and that means not necessarily congestion such as a phlegm but also by means of diuretic so if there's a lot of acute fluid accumulation due to cardiovascular causes we will give the patient diuretics that can help get rid of some of this fluid that accumulates to pulmonary edema and then certainly if there's infectious causes we want to give antibiotics which is also why we need to collect the cultures over here to find out what antibiotics are appropriate and then anti-anxiety medications remember we said the patient might be agitated have altered level of consciousness and imagine if you can't breathe you're going to be anxious patients might have this sense of impending doom that they are going to die now we have to be very careful here with the administration of these anti-anxiety agents especially in this hypercapnic respiratory failure where the patient's respiratory rate is already low because we know that any of these narcotics or benzodiazepines or sedatives might further decrease their respiratory drive so you have to be very careful and judiciously administer those kind of medications but they might just help take the edge off to where the patient can relax and just allow for the breathing to happen with that supplemental oxygen that will be administering and then we definitely have to monitor these patients very very carefully with some hemodynamic monitoring and the most important part here is to ensure end-organic tissue perfusion right we want to make sure the brain the heart the kidneys still get perfused and we can achieve this by maintaining a miniaturial pressure of greater than 60 versus darling blood pressure greater than 90 now if this is not the case if the blood if the these two values are lower than this then we would give the patient's IV fluid to get them hydrated and bring the blood pressure up but of course we have to be careful of those underlying cardiac arena issues with fluid administration and then certain medications that you can find in my pharmacology playlist will help bring up the blood pressure and those would be more like vasoactive drugs that cause vasoconstriction and therefore help bring up the blood pressure and then another important point here is we want to monitor their hemoglobin level remember oxygen is carried by hemoglobin throughout the body and then helps with the gas exchange well if I only have a hemoglobin of 7 that means that my blood volume is only at about 50% so I only really have half of the oxygen carrying capacity that I would normally have so if the oxygen the hemoglobin level is less than 7 then the patient will need a blood transfusion to kind of fill up their tank increase the oxygen carrying capacity and then the perfusion might improve there as well and we always have to think about nutrition any of these two acute causes of respiratory failure will put the patient in a hyper metabolic state they will be anxious they have increased heart rate their blood pressure is up they're agitated there's a lot going on and so we have to think about providing some nutrition to the patient which is why it's usually recommended to start enteral or tall parenteral nutrition within 24 to 48 hours after the patient's respiratory status gets stabilized which usually means that they're on some sort of a ventilatory help and then we can think about getting them the nutrition by whatever means is appropriate for the patient and the whole scenario the whole patient care for that particular patient so thank you for watching this video on acute respiratory failure I highly recommend watching the video on ARDS maybe PE as well as as my COPD all these other diseases here so that you know what they can really lead to which is this acute respiratory failure if we don't intervene one and which is basically a complication of all these diseases so please give me a thumbs up if you like the video subscribe to my channel there's more to come in the critical care playlist and I hope to see you soon here on nursing school explain thanks for watching