The secret to understanding fluids and electrolytes for nursing school is NOT memorizing all the lab values and normal ranges.
Instead, it’s understanding each contributing player, so that you can begin to understand and imagine how they all work together. That’s the part of fluids and electrolytes you need to master before you will ever feel confident enough to learn the more advanced nursing school topics in Med-Surg.
The body is filled with semi-permeable membranes, like blood vessels. That means that certain things (but not everything) can cross those barriers.
Understanding how fluids and other “stuff” (a highly technical term I use to refer to electrolytes, protein, glucose, etc ?) move around the body and across semi-permeable membranes is a complex dance…and it’s essential to understand if you want to do well in nursing. In fact, it’s the core of what it means to master fluids and electrolytes in nursing school.
Luckily, it’s not so hard to understand IF you can identify and understand the most important information.
What are the key factors that influence the body’s ability to adjust fluid and electrolytes?
Here’s the 4 most important things you need to know about passive movement of fluids and electrolytes in the body:
- Osmosis: Osmosis relates to the movement of water across a semi-permeable membrane. The water (fluid) wants to balance out the “stuff” (electrolytes etc) as much as it can to make everything equal. So if there’s more stuff on Side A of the semi-permeable membrane then there is on Side B, then more water will move to Side A until the “stuff” is equally diluted. Click here to see a cool experiment of osmosis in action.
- Diffusion: Diffusion relates to the movement of “stuff”. Generally speaking, “stuff” likes to have it’s own personal space. So whenever you have a group of “stuff”, they will spread out as much as possible…and in the human body, that often means that they’re spreading out within some sort of fluid. You can learn more (and get a great visual) on this blog post.
- Hydrostatic pressure: Hydrostatic pressure relates to the movement of fluid, and how strongly it is “squeezed”. The higher the pressure, the harder the fluid pushes to move out of that area…if it can. It’s like a water balloon…if there’s no hole, the water can’t leave the area. But if there’s even a tiny hole, then the high hydrostatic pressure pushes the water out hard and fast. However, as the water leaves, the hydrostatic pressure decreases, and the water gradually squirts out slower and gentler until it finally stops.
- Oncotic pressure: Oncotic pressure focuses on proteins in blood plasma. For nursing school purposes, we mainly need to think about albumin to get the basic idea, although there are technically other plasma proteins. Albumin is like a magnet when it comes to water, so it pulls water towards itself. Since Albumin is normally stuck inside blood vessels (it’s too big to pass through the semi-permeable membrane under normal circumstances), that means it is usually a force to pull and keep water inside the blood vessels.
Once you master these 4 basic ideas about passive movement of fluids and electrolytes, nursing school will start to get easier because you will be able to understand anything from what happens when blood pressure increases (hello edema!), all the way through the acute complications of a major burn injury (like hypovolemic shock).
Now, what I haven’t told you yet is that reviewing this foundational info is the very first step of the Silver Bullet Study System. I call it the Foundational 15, because you focus on one smaller topic (instead of trying to memorize All.The.Things. at the same time…), and you only spend 15 minutes reviewing it before moving on to other topics so that you still have time to study the things you’ll need for your next exam, too.
The best way to get the Silver Bullet Study System is by joining the Your Nursing Tutor VIP Membership…then you’ll be able to follow this easy, 4-step study system that lets you “kill 2 birds with 1 stone” as the old saying goes. And when you do this before every study session, you will be shocked at how quickly you start to feel more confident about fluids and electrolytes in nursing school.
Nicole is a Professional Nursing Tutor with over 15 years experience, and the founder of Your Nursing Tutor. She has a BSN, and an MA in Clinical Psychology. Nicole specializes in providing easy-to-follow, proven study methods (like the Silver Bullet Study System) that transform frustrated nursing students into calm, confident nurses! When she’s not helping students through her Live Tutoring Membership, Nicole loves spending time with her husband, homeschooling their 6 kids, and staring at sunflowers.