Pineapples and Cupcakes

white-coat:

Cerebral Edema - As you can see this brain even looks… swollen. The gyri are wide and flattened while the sulci (the “grooves” in the brain) are really narrow. Cerebral edema is divided into 2 subtypes: intracellular and extra cellular. Intracellular cerebral edema occurs when there not enough sodium in the plasma, or the body is retaining too much water and diluting the plasma concentration of sodium. If this happens, the water is going to go wherever there’s a greater concentration of sodium/electrolytes: inside the cell. This picture is an example of intracellular edema, all of that water rushed into the cells causing them to swell up. Extracellular edema is usually caused due to extra leaky blood vessels. This can be caused by infection, cancer, trauma, or certain types of poisoning (like lead). What are the signs of cerebral edema and the increased intracranial pressure it produces? Papilledema, which is when the optic disk in the back of your eye bulges out, headache, projectile vomiting (without nausea, because the vomiting center of the brainstem is being pushed on), your heart rate slows way down and the blood pressure shoots up (the brain is no longer able to regulate these things). Ultimately if left untreated the person will die.

In a patient with head trauma we purposefully hyperventilate them. This is so they breathe off as much CO2 as possible to cause respiratory alkalosis, which in turn keeps the cerebral blood vessels constricted. Why do we do this in emergency medicine? Because typically people with brain trauma breathe slow and shallow, causing a build up of CO2 (respiratory acidosis) and slowly cutting off oxygen to the blood stream (hypoxemia). When this happens, the brains reaction is to dilate the cerebral blood vessels to deliver more oxygenated blood to the brain. We don’t want this to happen because it will cause the swelling to increase and compress the brain, killing the patient.

(via white-coat-deactivated20111012-)