Proper blood pressure taking technique and what is an auscultatory gap??

8210286870_7eb9814892_z

In my second quarter of year two med school we are covering the cardiac system (2nd time since last year, but in more depth). We learned how to take a blood pressure last year and did some extensive practicing fall quarter this year, but we’re back at it again for the cardiac system. One step of the blood pressure taking technique we are taught is after applying the cuff we are to take the patient’s wrist and check for their pulse. We are to continue checking the pulse as we inflate the cuff so we know when the cuff is at the point where it is blocking the flow of blood. Inflate the cuff another 20 mmHg of pressure then listen with the stethoscope on the brachial artery as the cuff slowly deflates. We are listening for the blood as it begins to flow again as the cuff is deflating.3712792250_472cd5fa9c_z

 

 

 

 

 

 

 

 

What was surprising to me was that most clinicians that have taken my BP have not checked the pulse while inflating the cuff. Talking with my peers and instructors we found we’ve shared this experience. I’ve watched a clinician taking my BP pick a random number on the BP dial and inflate to that number. Here’s where the problem can come in: if there’s an auscultatory gap. An auscultatory gap is the temporary disappearance of the blood flow sounds while the cuff is deflating.

3461966586_bf45daf39f_z

It is most often seen in older patients and it is strongly associated with hardening of the arteries. The problem with not checking the pulse while inflating the cuff is that the patient’s blood pressure could be grossly underestimated if the reading is unintentionally begun in the gap. Checking the pulse ensures that the top, and true, systolic pressure is reached before beginning the reading.

 

 

 

 

 

 

mind-the-gap

References:

Frech, T. M., Penrod, J., Battistone, M. J., Sawitzke, A. D., & Stults, B. M. (2012). The prevalence and clinical correlates of an auscultatory gap in systemic sclerosis patients. International Journal of Rheumatology, 2012, 590845. doi:10.1155/2012/590845

Cavallini, M. C., Roman, M. J., Blank, S. G., Pini, R., Pickering, T. G., & Devereux, R. B. (1996). Association of the auscultatory gap with vascular disease in hypertensive patients. Annals of Internal Medicine, 124(10), 877–883.

Drinking liquids during meals… is it healthy?

I’ve been thinking about this topic for awhile. Actually, since one day in my physiology class last year. We were talking about gastrointestinal motility patterns.  And why would that be the one on my mind recently? While we were learning about how fast different meals empty from the stomach I was thinking about something that I had heard about back in my days of reading random things on health and nutrition. Somewhere there emerged an idea that drinking water with meals was detrimental to digestion.Bella eating zucchini bread

The suggestion was that the water would lower the pH level of the stomach and dilute the digestive enzymes, thus making food harder to digest. According to the internet this could cause indigestion, heartburn, irritability, bloating, lethargy, headaches, insatiable cravings, inability to determine hunger, depression. I’m wondering if it also caused the dust all over my house and those pesky lost socks!

I never could get truly into this way of eating because I quickly found that telling myself that I couldn’t have liquids during meals made me want them that much more! Not to mention there are several foods that are a challenge for me to swallow without liquid.article-2238428-005CD67400000258-197_233x423

What we learned in physiology that day was that the rate that liquids empty the stomach is faster than any other component of a meal.

Gastric emptying

The figure to the right shows that liquid empties from the stomach in about 20 minutes, much faster than the semisolid or solid foods, which take from 60-100 minutes. So, the liquid isn’t going to be in the stomach for long, messing with your stomach pH. Second, the pH of the stomach is LOW, about 0.7 to 3.8 which is very acidic. So acidic that there isn’t much that can change that except food, which only brings it up a small amount.

In my undergrad I did some experiments in chemistry with making an acidic solution less acidic (more basic), and I can tell you without a doubt  that water alone is not going to change the acidity of a mixture.  The other thing happening in your body is what physiologists call the cephalic and gastric phases of digestion. In the cephalic phase we are thinking about and anticipating eating. As you are preparing your meal and just about to sit down to eat it you are anticipating eating it and this is releasing gastric juices in your stomach. The gastric phase is while we are eating and our body releases more gastric juices.

The summation of all this is that drinking liquids during your meal is not going to lower your stomach acidity. You are still going to make plenty of stomach acid (providing things are working correctly in that area in the first place), and none of the liquid you are going to normally drink is going to change the pH level of that stomach acid.

So if you want feel free to enjoy your beverage with your meal again!Flash-Chill-TAKEYA-Iced-Tea-Beverage-System

References:

Rhoades and Bell,  2013, Medical Physiology: Principles for Clinical Medicine, fourth edition, (pgs 494-495, 509)