Week 2: Have some Heart and a Bunch of Cool Random Facts, such as Babies can't Shiver

Week two has absolutely flown by in a blur of fascinating information, practicing skills, and late-night studying. I've read a ton of chapters in all my different books and enjoyed learning about vital signs, perfusion, and patient safety. Below, I share some interesting information I've learned or am still learning. If you notice something I wrote is wrong, please comment on the post and let me know so I can fix the error (both in the blog and in what I thought I knew).

I thought I'd share some of the most interesting facts I read this week:

• Neonates (newborns) are physically unable to shiver which is why it's important to keep them warm
• During a menopausal hot flash, a woman's skin temperature can increase by 7.2 degrees Farenheit!
• Normally, carbon dioxide levels in a person's blood is what stimulates them to breathe. However, in patients with certain chronic lung diseases, low levels of oxygen are what stimulates them to breathe so if you give the patient supplemental oxygen, they will no longer receive the impulse to breathe and could die.
• Men, women, and kids breathe different from each other. Men and kids do "diaphragmatic breathing" while women rely more on their thoracic muscles
• And the most interesting fact I read this week has personal ties to my family. I was reading about hyperthermia and there was a section about Malignant Hyperthermia, a hereditary condition. I stared at that phrase for about three minutes thinking, "why on earth does this diagnosis look so familiar?!" And then it hit me - oh yah! I think I carry a card in my wallet warning medical professionals that my family has this problem. So I read the information about Malignant Hyperthermia very carefully and discovered that it's a reaction to certain anesthesias which causes the body to have uncontrolled heat production. Basically, if my family gets certain anesthesias (for instance, we can't have general anesthesia), we cook ourselves to death. Lovely, right?

One subject that I've been struggling with memorizing this week is different heart tests. We studied the heart in the "perfusion" chapter and there was a list of tests and what they did and how they were performed. The only test I was familiar with was cardiac catheterization since I've gotten to see one before (they're so cool!). I thought I'd briefly explain about each test and include an informational Youtube video with each one. The videos really helped me learn about the tests as they not only explain the why and how, but also show the actual procedure.

So first, cardiac catheterization. I've seen it on an EMS patient having a heart attack. He was taken into the cath lab and I was allowed to stay and watch as the doctor threaded a catheter into the patient's coronary arteries and injected a dye. Then, he did a quick x-ray which showed the arteries in detail. We were able to see the blocked artery. I would have been able to stay and see the stent placed but we had to go since there weren't enough ambulances in service in the county and we had to get back in service. However, I read about cardiac catheterization and watched a Youtube video so got to see a stent placed. ;-D

During a cardiac catheterization, the patient is awake yet usually given a sedative to keep them calm. At different points in the procedure they might feel palpitations, a hot flash, or the desire to cough. Also, the patient needs to alert the doctor if they are allergic to iodine. First, the doctor threads a catheter up to the heart via the brachial or femoral artery and the right side of the heart is examined. Depending on what the doctor finds, it might be the only side of the heart catheterized. If the left side of the heart is also examined, the doctor might either puncture the catheter through the heart's septum or thread it through an artery going against the blood flow. This procedure can be used to visualize the heart and its arteries, fix a blocked artery, retrieve a heart/blood tissue sample, and measure intracardiac pressures.

Here's a video to see a cardiac catheterization:

Echocardiography is performed on a patient using ultrasound waves, kind of like when a pregnant woman gets to see her unborn baby. There's a transducer with lubricant placed on the patient's chest at the 3rd and/or 4th intercostal space and the heart and its valves can be viewed. This procedure is used to diagnose cardiomyopathy, valvular disorders, pericardial effusion, ventricle function, ventricular aneurysms, and heart tumors. During the procedure, the patient lies on his/her left side and the head of the bed is elevated 15-20 degrees. The procedure takes about 30-60 minutes and is completely painless.

Here's a video to see echocardiography: http://youtu.be/1ByIMUcdMUw (Sorry, trying to get Blogger to find it on Youtube was being a pain so I'm just giving the link)

Transesophageal echocardiography is the one I found the most interesting since the patient has to be sedated and is given anesthesia to stop their gag reflex. Then, an ultrasound transducer is inserted down their throat and into their esophagus. The ultrasound shows the posterior side of the heart.

Here's a video explaining and showing a Transesophageal Echocardiogram:

A PET (Positive Emission Tomography) scan uses radioisotopes and assess the relationship between cardiac perfusion and metabolic function (specifically how much glucose an area is using). It is usually used to diagnose tumors but in the heart, it's used for finding ischemic tissue.

Here's information about a PET scan:

Finally, an MRI (Magnetic Resonance Image) can be used to take a picture of the heart. It's noninvasive and made by interaction of magnetic fields, radio waves, and atomic nuclei showing hydrogen density. It can show different types of tissues because of how the tissues use hydrogen. However, before an MRI, the patient must remove any metallic objects (rings, phones, keys, etc) and might be unable to have the scan if they have a pacemaker or automatic defibrillator. Also, the scan is in an enclosed machine and takes about 15-60 minutes so the patient might experience claustrophobia.

Here's a video about MRIs:

If you've made it through all this information to the end of the post, I'm shocked! :-D Anyway, I hope you learned something! Once again, if you see that I've included any erroneous information, please comment on the post and let me know so I can change it.

....Until next week!