Robin Lester's ICU Trivia
Q: Where would your needle insertion be if you were...
- ......performing a pericardial centesis?
- ......aspirating a pneumothorax?
- ......removing fluid from the chest cavity?
- ......intracardiac injection?
Just a bit of "trivia" to see how many of you still remember your anatomy. There are two different schools of thought when performing a pericardial centesis. It can be done from either the left or right side but do you know why one might prefer to tap from the right side of the chest as opposed to the left? (hint: what could you possibly hit or lacerate when tapping from the left side)
Q: Do you know what kind of quick and easy test can be performed to determine if the bloody fluid you tapped is truly from the pericardial sack or if it is directly from the heart?
***Scroll Down to the Botton of the Page to Find Out the Answers***
A: Needle insertion for...
- Pericardial centesis is generally performed at the 5th or 6th intercostal space at the costochondral junction. It can be done from either left or right side but you're less likely to hit or lacerate the descending coronary artery if you tap from the right side of the chest.
- Pneumothorax tap we use the 7th or 8th intercostal space dorsal (higher) on the chest wall in a laterally recumbent patient......to tap for fluid it would be lower on the chest wall (7th or 8th intercostal space)
- Chest tap "sites," for a pneumothorax or pleural effusion, will depend a lot on the recumbency of the patient or whether they are
standing or sitting. It is recommended the patient be in lateral recumbency for aspirating a pneumothorax and either sitting, sternal or
standing for the tapping of fluid.
Just remember this: air rises and fluid falls.
- Intracardiac injections can be done at the 3rd or 4th intercostal space at the costochondral junction.
A: The test that can be performed to check if the fluid you aspirated was from the pericardial sack or directly from the heart is called a "clot" test. Very simple. Place a sample in a red top tube. If it clots then you have blood directly from the heart...if it doesn't clot, you have successfully tapped the pericardium. You can also compare your fluid against a PCV of peripheral blood....."hopefully" your PCV will be higher. (ie: it should be higher or you're probably going to need a blood transfusion very quickly)!
One other helpful thing to check when doing a pericardial centesis...check the pH of the fluid with either a urine dipstick or litmus paper. A pH < 7 is consistent with an inflammatory process and a pH >7 is suggestive of neoplasia.
An Extra Thought...
Just to mention a few things....whenever you tap any kind of fluid from the chest (or abdomen for that matter), you should save some of the fluid in a large red-top vacutainer tube, a purple-top vacutainer tube as well as a small red-top tube for culture and sensitivity. It would also be wise to make a few slides of the aspirate as well and if the fluid is bloody to spin it down in a hematocrit tube and get a PCV reading on it. Like I said earlier, you hope it is less than that of the peripheral circulation.