Special Tests in the Lung Examination

00:01 Alright, so having auscultated the basic breath sounds and adventitious breath sounds and done chest percussion, if we found any abnormalities in any of those things, we would next want to do a test for vocal resonance.

00:12 The way to do this is you're going to again, put on your stethoscope, and you're going to particularly listen to the areas where you heard something that didn't sound quite right and you're going to be comparing that with the other side.

00:24 So, let's say that I heard some dullness in this area -- I put my stethoscope here and then what I'm going to have the patient do is simply vocalize relatively quietly the alphabet or counting to ten, it really doesn't matter, you're just trying to get them to speak out load.

00:40 So Shaun, if you wouldn't mind just quietly counting from 1 to 10.

00:43 One, two, three, four. I'm comparing both sides.

00:50 Five, six, seven. Above and below the area where I thought I've heard something unusual.

00:55 Perfect. Now, normally, when you have a patient speak and you're trying to listen in the peripheral lung fields, you can't hear anything.

01:04 It's just muffled kind of sounds, certainly I'm hearing him vocalizing something, but I have no idea what is being said, I can't hear consonants or syllables or anything like that.

01:12 When you can actually hear things more crisply, more robustly, we call that broncophony.

01:20 Broncophony, which is basically that the bronchial sounds, we were talking before about bronchial breath sounds which is the sound of vibrations from your voice box or from your airways going down the large airways out to your stethoscope? If you can hear actual words, the sound of people saying words, we call that broncophony, and if you can hear it even more crisply, you can actually make out the words, we call that pectoriloquy.

01:45 And this goes back to Rene Laennec's descriptions of the lung sounds.

01:50 He used the ancient Greek to describe pectoriloquy as chest talking, remember pect means refers to the chest, the pectoralis muscles is the chest; iloquy is from the same root as the word soliloquy which is a person talking alone on stage; while pectoriloquy is the chest talking and it's based on the idea that if I can hear somebody actually talking through my stethoscope, I'm hearing the chest talk. The reason that that is a marker of disease, is that it means that his voice box is vibrating when he's making words and that sound is being transmitted through the large airways to some sort of solid tissue, again a tumor or a pneumonia, that is conducting those vibrations directly through his chest wall right to my stethoscope, as opposed to being broken up and defused through those feathery breath sounds that we describe as vesicular earlier. So that's pectoriloquy.

02:46 And a particular, you want your patient to be whispering when they count off those numbers or letters, because if they're speaking loudly, I'm going to hear it directly through my ears without even the stethoscope on, so he needs to whisper, and that's why they call it whisper pectoriloquy.

03:01 So, again, the first thing you're going to hear is just broncophony, that's where there's clearly a subtle distinction between the mumbling subdued sounds of what you would normally hear in healthy lung tissue, then there's broncophony and then the next step would be whisper pectoriloquy when you can really hear things very crisply.

03:20 I encourage you to listen again over the peripheral lung fields while speaking, and then do the same thing while listening again to your trachea and again go through those numbers one through ten and you'll appreciate the differences between how those things sound.

03:34 The last part of vocal resonance is so called "eeee" to "aahhh" changes.

03:39 So, again, you're going to listen in a particular area.

03:42 I'm going to have Shaun just say the letter E for me.

03:47 E. Great, again. E. Again. E. And again. E.

03:54 So this test is called egophony, which also goes to ancient Greek, it means goat sound and essentially Rene Laennec, again, who described a lot of these stuff when he created the stethoscope back in the 1800s, described what he referred to as the bleeding of a goat.

04:11 Normally if I just listen to somebody's chest and somebody says "eeee", that sound is transmitted to my stethoscope and it sounds like "eeee".

04:19 However, if that sound is moving through solid tissue, again, like a cancer or a consolidation in the lung, that sound for phonetic reasons that I honestly don't perfectly understand myself, the sound of "eeee" get's subtracted out to the sound of "aahhh, aahhh." So he said, "aahhh" is the bleeding of a goat that's why he called it egophony.

04:42 When you hear that sound, especially if its asymmetric on one side compared with the other, it has a significant likelihood ratio when support of there being some sort of consolidation in the lung in that area, so it's absolutely worth looking for and can be very helpful to make your diagnosis.

04:57 And now, the last part of the lung exam on the chest is looking for tactile fremitus.

05:04 Fremitus describes the normal vibrations that are happening in the chest when somebody is speaking and its fairly subtle but it's normal to have some degree of tactile fremitus which is simply done by applying usually the ulnar surface of the hands because that's where we're best able to detect the vibration, and if I could just ask you to count to ten for me again.

05:26 One, two, three. So as he's speaking, and you can speak a little bit louder, Shaun.

05:33 Six, seven. I can clearly feel vibrations in my hands as I march up his, the back of his chest.

05:40 In a patient who has, again, a significant lung consolidation, those sounds of -- from, they're coming from his voice box from his larynx, are now going to be accentuated as they pass through solid tissue, so you'll have increased tactile fremitus that'll be transmitted to my hands.

05:57 In contrast, if he had an effusion in there, and remember, dullness to percussion is going to be the same whether it's an effusion, you know, fluid or if it's a solid. So dullness to percussion can't tease those two things apart, but if there's a consolidation, you'll have increased tactile fremitus or if there's fluid, those vibrations from his larynx are not going to be transmitted through fluid, so you would have decreased tactile fremitus.

06:21 And by having him speak loud I'll feel normal fremitus on one side and I'll feel the absence of fremitus on the other side, if that's where the effusion is located.

06:31 Some people say that you should be saying the word 99, it honestly doesn't matter as long as this patient is speaking loud enough for you to feel fremitus, they can say whatever you'd like them to say.

06:42 That concludes this portion of the lung exam.

06:46 Now we're just going to talk about one last feature that's important to look for.

06:50 So this last feature that we're going to look for is called clubbing and often times you will see patients who have what looks like these swelling, these protuberances on the distal parts of either the fingers or the toes.

07:02 It's important to realize that while a lot of the conditions that cause clubbing are associated with hypoxia, it turns out that hypoxia actually has nothing to do with clubbing, it's just a coincidence that many of the things that cause clubbing also happened to cause hypoxia.

07:19 And in fact, many a time have I had a patient with COPD and medical students identify that this patient has some degree of clubbing which they presume was caused by the COPD, but I have to remind them that actually clubbing portents some other diagnosis and often times that diagnosis could be something fairly significant like a lung cancer.

07:38 So the best test to identify clubbing at the bedside is called Schamroth sign, and it's based on the idea that the Lovibond angle, which is the angle between the proximal nail fold and the nail plate should be concave, that means that it should be going inward.

07:56 In patients with clubbing, also known as acropachy, there's increased tissue fibrosis underneath the nail plate that pushes that Lovibond angle out until it's either flat or even potentially a little bit convex.

08:11 So all I'm going to have Shaun do is lift up his 3rd, his fingers on both hands specifically his ring fingers and bring the distal digit together and you're looking for a little tiny diamond to show up at that junction between the proximal nail fold and the nail plate.

08:31 If that diamond is preserved, the patient does not have clubbing; whereas if it is obliterated and that little corner is coming together on both fingers, then that would suggest that clubbing is present.

08:45 Now clubbing we see it in things particularly involving the chest like bronchiectasis, cystic fibrosis.

08:52 I mentioned lung cancers, a variety of different conditions.

08:56 In fact, 80% of the time that you find clubbing it is associate with a pulmonary condition, not COPD to be clear. The other 20% are from oftentimes congenital cyanotic heart disease and hepatopulmonary syndrome, and a variety of other things as well.

09:12 That concludes our examination of the respiratory system.