 Welcome back to an emergency medicine video on shock. We would discuss the first three types of shock in this part. That is septic, hypovolemic, and obstructive shock. We'll go through what each one is, how the patient might present, and how we should treat it specifically. First, septic shock. Septic shock occurs where there is an infection that causes significant peripheral vasodilation. Because of the significant peripheral vasodilation, there is decreased systemic vascular resistance. Because of the pooling of the blood in the periphery, there is decreased venous return. Because of that, intravascular volume now decreases. On the other hand, sepsis can also cause myocardial depression and causes decreased cardiac output. Those are the reasons that sepsis cause shock. The patient will present with signs of infection. Sometimes they can be settled. It's up for us to find them. They might have a fever. On examination, we want to be looking for any signs of infection, so we'll start with the ears, the throat. Looking for next stiffness that may signify meningitis, sputum production, cough for pneumonia, abdominal pain, any dysuria that signifies any urinary tract infection. We're also looking for cellulitis in the extremities or any part of the skin. Due to the peripheral vasodilation, the patient who is in septic shock will be warm and flushed. Also known as warm shock. They're often tachycardic. And the pulse pressure, which is a difference between the systolic blood pressure and diastolic blood pressure, can be high. Remember in part one, we talk about the end organ dysfunction. So don't be surprised that the patient in septic shock may have changes in their cardiac output because of ischemia or arrhythmia. They might be confused or have decreased level of consciousness because of central nervous system involvement. On top of whatever infection they have, they may also have signs of ARDS or pulmonary edema in the lungs as well. So on examination, we want to look for those. What about labs? On top of what a shock patient might get, septic shock patients might also have a much higher white blood cell count and an increased lactate. In terms of other labs, we also want to look for the source of infection. That might mean urine and blood cultures, chest x-ray for pneumonia, may even lumbar puncture for suspected meningitis or encephalitis. The diagnosis of septic shock is a patient in shock who has signs of infection. The main treatment for septic shock is large volumes of intravenous fluids and early broad-spectrum antibiotics. It is not uncommon for patients to get three to five liters of IV fluids quickly in the course of their treatment. Sometimes patients might receive blood or a vasopressor after the fluids is being given. The vasopressor of choice can be dopamine or norepinephrine. We often insert a foley catheter to measure urine output. Sometime a central venous line would also be inserted as well. Next, we will discuss hypovolemic shock. This is the most common type of shock. It either occurs because of volume loss of blood as in trauma or GI bleed or fluid as in burn, vomiting or diarrhea. Patient in hypovolemic shock will be preferably shut down with poor perfusion also known as cold shock. They're usually tachycardic. Their pulse pressure will be narrow. On history and physical examination we'll be looking for any focus or sources of blood loss or volume loss. It could be asking for any bleeding history from the GI source to the GU source any vomiting or diarrhea any history of trauma and again on physical examination we'll be looking for any signs of bleeding sources or volume loss. In terms of lab, the hypovolemic shock patient might have a low hemoglobin if they've been losing blood. On the other hand, if all they've been losing is fluid their blood will actually be hemoconcentrated so their hemoglobin might look much higher. Their creatinine on the other hand might also be higher as well. On top of all the labs you order please remember to do a pregnancy test. On all child-bearing age women since a ruptured topic pregnancy can cause significant blood loss and therefore shock. The treatment for hypovolemic shock is fluid. We often start with intravenous crystalloids fluid such as normal saline or ringer's lactate. If the patient has significant blood loss we will try to do two things. We'll first try to replenish the blood loss. In number two we want to stop the bleeding. That might mean going to the endoscopy suite for a GI bleed or going to the OR for the trauma patient or the ectomic pregnancy patient. Next obstructive shock. It happens when there's blockage of blood flow from the heart. It can happen for a few different reasons. In a tension pneumothorax let's say this is the collapsed lung more air filled from this space will cause the mediastime to be squeezed to the other side and that would decrease the blood flow from the heart. In a cardiac tamponade there's now lots of fluid in a pericardium and now that is squeezing in the heart to decrease the blood flow. Also if there is a pulmonary embolus then the pulmonary blood flow is obstructed causing decreased blood going out from the heart. How do these patients present? In the case of the tension pneumothorax you expect the patient to wear shortness of breath decrease breath sounds to that side increase JVP and tracheal deviation to the unaffected side. In a patient with a cardiac tamponade you expect decreased heart sounds increased JVP because of poor venous return. In a patient with PE the standard PE symptoms such as pleurotic chest pain, shortness of breath any signs that's compatible to a DVT would also be present. In terms of diagnosis if you see a patient with a deviated trachea decreased breath sounds increased JVP you know there is a tension pneumothorax and you don't have to wait for a chest x-ray to make that diagnosis. In terms of tamponade bedside ultrasound will show you a pericardiofusion and ECG might show small voltages. For a diagnosis of PE if the patient is stable a CT chest would give you the most information. What about treatment? We often start with giving IV fluids first to patients who are in obstructive shock. However, as you are examining the patient if you have a suspicion of a tension pneumothorax we treat that by a needle decompression followed by a chest tube. If there is cardiac tamponade then a pericardiocentesis is used to get rid of the fluid around the heart. If the patient has a pulmonary embolus anti-coagulation and sometimes thrombolysis would be used to treat that. Those would be the specific treatment for these specific kinds of obstructive shock. In summary we discussed three different kind of shock. First there is septic shock where the patient might have a source of infection. The treatment is lots of IV fluids, antibiotics and vasopressor. The next shock we looked at is hypervelemic shock either due to blood loss or volume loss. The treatment is IV fluids, blood if necessary and stopping of ongoing blood loss. Lastly we talked about obstructive shock that is due to a tension pneumothorax pericardiofusion or pulmonary embolus and we discussed its treatment. Next we'll finish up with cardiogenic shock and anaphylaxis in part 3.