Learning Outside the Classroom

A few weeks ago I had my last day as a CNA in a convalescent home. In no way did I anticipate what an emotional experience that would be. My almost two years in that position were, without a doubt, the hardest thing I’ve ever done. I was hit, scratched, spat on, cursed and yelled at, vomited on, had urine splash on my face–and once had projectile, bloody diarrhea hit my face. Fortunately the communicable diseases spared me.

I’ve cared for people who weigh over 300 lbs., have C. diff, and have no ability roll over. let alone stand up. This means that the CNA needs to roll their body over for diaper changes, which are frequent with C. diff. Some patients don’t want their nasty, soiled, diaper changed, and push back on the wall as hard as they can while you try to push back with one hand and position the clean diaper with the other. I worked in a “no lift” facility but everyday lifted several people from the bed to the wheelchair. Yes, I’m massaging my own back right now.

Receiving my CNA certification, May 2014
Receiving my CNA certification, May 2014, with my teacher Abigail.

Most of the patients were really wonderful–being old can make one aware of their own vulnerabilities, and very tender and appreciative. But sometimes it’s the opposite, and some are struggling with serious issues. Imagine being an older woman with Alzheimer’s, in a nursing home, with no family visiting ever. I can’t imagine how vulnerable that would feel (and hope I never do).

Unlike the hospital, in a convalescent home the CNA spends more time with the patients/residents than anyone else on staff. The care in this setting is generally not urgent–for the most part the patients require help with bathing, toileting, dressing, and sometimes feeding. Because of the longer length of residency, CNAs get to know patients pretty well and are also responsible for reporting any changes in behavior–confusion, lethargy–and are usually the person present when things do become urgent, due to a fall, a stroke, or simply due to dire health that on a typial day is not quite bad enough to require hospital care.

RN and LVN positions have government imposed nurse/patient ratios, but that’s not the case for CNAs. It’s determined by the facility, and mine was about average–about eight patients during the day shift. It doesn’t sound like a lot–you might think “oh, eight patients, that gives you an hour with each person”. But we also pass breakfast and lunch trays, help feed some, change linens, take and record vital signs, and chart everything we do in the day for each person–did they eat, how much did they eat, are they self ambulatory in bed, out of bed, in the wheelchair, do they use a walker, do they need help getting dressed, how much help, did they have any snacks, how much, did they have any bowel movements or urinate, how many, at what time, was the stool hard, soft, or watery, do they have a catheter, how many cc’s of urine was collected, did they shower or sponge bath, how much help did you provide, did they leave the facility for any reason, were they turned and repositioned every two hours, etc. It’s A LOT of work.

I made $12 an hour, which was more than most of my co-workers. The health benefits, had I taken them, would have cost $900 a month for me and my family. We waived them and continued with our individually purchased plan, which was cheaper. My heart goes out to several co-workers who have worked that job for 10+ years, are wonderful, and such care for the residents as if they were their own family. They taught me so much, most importantly, what is true of every nursing job: that it simply is not ever, about you.

Tonight I start my first day on my own in my new position as a CNA in the Obstetrics unit, helping Mom’s with their new babies. 🙂


The Nervous System I

A quick note to promote Coursera, an aggregator of online classes–if you’re planning to take Physiology anytime soon, I highly recommend taking it here first as a primer, especially if you have no familiarity with the material. The Duke University curriculum and instructors are excellent–and free! You should also consider it if you’ve already taken physiology but feel like you need to brush-up before taking the NLN PAX.

Now on to the nervous system–our nervous system, like the circulatory system, engages every part of our body. But instead of veins, arteries and capillaries, it’s comprised of axons, dendrites and glia, conducting electricity. Working in conjunction with the muscular system, it allows us to move and breathe. And because the heart is a muscle, it keeps the engine of the circulatory system humming. It helps to keep our vitals systems in homeostasis by communicating dangerous rises or drops in blood pressure, heart rate, pH, O2 and CO2 levels and sometimes releases neurotransmitters into the blood to move these systems back to setpoint. Lastly, it communicates a variety of sensory messages to the brain.

So how does all this communication happen? There are two main components: the electrical signal, and the network on which it travels.

The Electrical Signal
The fluid inside and surrounding our cells (intracellular fluid, ICF, and extracellular fluid, ECF) is filled with chemical elements—mostly sodium (Na), Potassium (K), Calcium (Ca), and Chloride (Cl). If an element has more or fewer electrons than protons, it has an electrical charge and is called an ion. The charge is measured, + or -, in millivolts (mV). Remember that.

A plasma membrane, the protective wrapper of the cell, separates the ICF and ECF. The mix of ions in the ICF and ECF determines its voltage, and the difference in voltage between the ICF and ECF determines the membrane potential for that cell. For example, at rest, most neurons have lots of K+ in the ICF and lots of Na+ in the ECF. The difference in voltage is about -70 mV, and this is the resting membrane potential (RMP) for the cells of our nervous system, aka neurons.

When a stimulus occurs–the smell of pancakes, a sting on your leg, even a slight breeze on the hairs of your forearm–voltage-gated Na+ channels on the plasma membrane open and Na+ rushes into the cell. This changes the difference in voltage between the ECF and the ICF and the membrane potential rises–depolarization of the neuron begins. Remember, it starts at -70 mV, the RMP. If the stimulus is strong enough, and enough Na+ moves into the cell,  the membrane potential rises to +30 mV, and an action potential, or electrical signal is fired. The action potential then travels the length of the axon to your brain, where the stimulus is registered and another signal is sent from the brain to your muscles–you decide to eat pancakes, move your leg, or put on a jacket.

In the center, the signature of an action potential. Around it, the phases of cell depolarization and repolarization.

Once the membrane potential reaches +30 mV and the action potential fires, the Na+ channels shut and the cell repolarizes. If the stimulus continues, another action potential is fired. Of course this all happens in femto seconds and is happening in more than one neuron–your fingertips have as many as 100 touch receptors per cm2.

An example of a medication that tweaks our nervous system, as many of our medications do, is lidocaine, which binds and inhibits voltage-gated Na+ channels. Liocaine is what the dentist injects into your gums before drilling your teeth. By inhibiting the voltage-gated ion channels of the neurons in your gums, there is no Na+ entering the cell, no cell depolarization, no action potential fired–no stimulus of the pain/nociceptors, and no pain felt.

That’s a lot of info–welcome to #nurselife! And that’s probably enough info for now. I’ll cover the network that all these signals travel upon next time–the information highway of our bodies! 😉


The Heart

Although it is not the only orheart-loresgan necessary for survival—the brain, liver, kidneys (at least one), pancreas, and lungs come to mind–we still regard the heart as most integral to life, most likely because of its central location and role in pumping blood throughout our entire body.

As children it was probably the first organ we learned about. That it was possible to press your ear to someone’s chest and hear it encouraged the attraction—bump-bump, bump-bump, or in the medical world, lub-dub, lub-dub—we know it’s beating, without the aid of special instruments. Conversely, assessing the health of other organs requires lab results, scans, or other medical diagnostics. But confirmation of the heart’s function is palpably evident.

As heart transplants become more common, our most familiar organ may lose some of its status; indeed, in cardiac units around the country, many patients today are being discharged not only with a donor heart, but increasingly, a completely artificial, mechanical heart.

Here are some facts:

  • 5.5 L: the amount of blood in the adult body (men have a little more than women)
  • 60-80 bpm: the number of times the heart beats in a minute

The completion of one entire circuit, meaning that the blood travels from the heart through the arteries, out to all tissues and organs, and then returns to the heart via the veins, takes about one minute. There is no area in the body for blood to be stored—it is constantly moving. So in one completed circuit, all 5.5 liters of blood is pumped through the entire body, in one minute. Impressive, right? The heart is not lazy.

Blood travels to organs and tissues primarily to keep them oxygenated. Without that key element our organs would stop working. O2 is required to by every cell in the body to complete specific functions, depending on the type and location of the cell. Our cells are like us, but smaller. They make things, require certain nutrients, and create waste. All that activity keeps our metabolism going–it is our metabolism. A byproduct of that activity—the waste–is CO2. CO2 is transported in the blood from the tissues and organs, via the veins, back to the heart, and then to the lungs, where you exhale it out of your body. More on that in circulation, which is fascinating and happens 24/7 without us ever thinking about it.

The heart has heart-lores-labeledfour chambers: two halves, with two chambers each—an atrium—some call it an auricle—and a ventricle. Each atria and ventricle pair pump blood to a different part of the body. The right half supplies the lungs with blood (via the pulmonary circuit), and the left half supplies the entire body and brain with blood (the systemic circuit). Because the left ventricle pumps blood to a much larger area than the right, it is larger and much more muscular than the right ventricle.

It’s important for the blood to move in one direction through the heart–for it not to backup–and this is controlled by valves. There are four of them: one between each atria and ventricle pair and another leading out to either the pulmonary or systemic circuit. Blood fills the atria first (both left and right atria fill at the same time), pressure builds, the atria contract, and the bicuspid and tricuspid valves open.

The first sound—the lub—is the sound of the bicuspid and tricuspid valves closing. Blood then fills the ventricles, pressure builds, the pulmonary and aortic valves open and blood moves out of the heart into the pulmonary and systemic circuits. The second sound—the dub—is the sound of those valves closing. And the entire process starts over from the beginning.

The heart contracts about 80 times a minutes for our entire lives. An electrical impulse, conducted by nerve cells, or neurons, is what keeps our hearts pumping continuously throughout our lives. I’m working on a post on the nervous system next, but a quick intro is necessary when talking about the heart. Electrical impulses or signals are carried throughout the body by the nervous system. The nervous system is mostly communicating with muscle and endocrine (hormones) cells.

The heart is constructed of muscular tissue and also covered in a web of neurons. This is significant because in addition to the neural communication occurring with the individual muscle cells of the heart–the myocytes–the neurons surrounding the heart muscle are providing a separate set of instructions.

These nerve fibers converge at a few key places in the heart, into nodes. The SA node, short for sinoatrial node, is also called the pacemaker, because it is where the electrical stimulus in the heart oriheart--nerve-fibers-and-labeslginates, and it sets the pace for the electrical impulse as it travels to several other nodes and bundles of conducting fibers. It sets the pace for the heartbeat and can be sped up by the nervous systems if we experience a surge of epinephrine and the fight or flight urge. An ECG is measuring the electrical activity of the heart and can indicate damage to the SA node and the accompanying nodes and conducting neurons.
This electrical pulse originates the contraction of the cardiac muscle; as long as the SA node is intact, the heart will continue to contract, or beat, even if lifted from its protective space in the thoracic cavity. It is timed specifically to contract the atria first (remember the atria fill with blood first, then the ventricles), then pause so that the atria have time to empty completely before the electrical pulse moves to the AV node, which controls contraction of the ventricles. Not having a pacemaker, the AV node relies on the SA node–the pacemaker–to set the heart rate. Although surgical implants of a pacemaker is high on the list of unnecessary surgeries, if it’s truly needed it’s a lifesaver.

Most neurons need a stimulus to send a signal, or “fire”. Interestingly, the SA node will fire action potentials in the absence of any stimuli. These spontaneously active cells have a precise balance of voltage-activated ion channels that allow the cells to fire without a stimulus.

Most of the ways to keep your heart healthy are also ways to keep your entire body healthy:

  • Adequate Sleep—7 to 8 eight hours a night
  • Blood pressure—high BP causes excessive stretching of arteries, which causes scarring, then plaque build-up, then narrowing, then arteriosclerosis—not a good trajectory!
  • Reduce Sugar intake—high glucose levels also cause arteriolosclerosis
  • Sit less, sweat more
  • High-fiber diet—also good for your colon and weight control
  • Dental Hygiene
  • Manage Stress—exercise and sweating help with this

So that’s the heart! I’d love it it you had questions, or if you’re also a nursing student, I’d love to hear what path you’re taking and where you are in your studies.