Welcome to Talk EM, brought to you by the Emergency Medicine Institute, where our goal is promoting clinical excellence. Our focus is the advanced practice nurse, emergency medicine nurse practitioners and physician assistants who work in the field of taking care of people who are really sick. Our whole goal is just that, promoting clinical excellence, to discuss the issues that are pertinent to us in the clinical practice.
I acknowledge that we all learn medicine a little bit different. We have differences in our commitment to medicine. When I say that I mean, I know some people who’ve been passionately called to medicine. I feel like I’ve been passionately called to medicine. It’s my calling. Other people that I know, it’s a job for them. It’s a nine to five kind of job. They’re kind of a paycheck employee. There’s nothing wrong with either one of those. We just have different callings. I guess that can go in any field. If you’re a policeman, or fireman, I guess you got paycheck employees and you got people who are really committed to their craft.
If you are embracing this content, this podcast, the video cast, or the blog, you’re not a paycheck player. You’re taking steps above and beyond the call of duty to learn, because you know when a patient’s in front of you there are expectations. If you are an advanced practitioner you know what it’s like to not have the answers. You know what it’s like to be in an experience and thinking, “I don’t know what to do here.” If you’re embracing our content it’s because you’re one of those that seek to really learn, and know and grow. We’re kindred spirits.
Today we’re going to talk about something that’s very basic. My whole hope is that it gives you real tools to change some of your strategies and thoughts. We’re going to talk about vital signs today. That’s all, basic vital signs. We’re just going to talk about basic vital signs and how as an advanced practitioner, working in emergency medicine, you should use them. There are way too many things that happen in emergency medicine that we learn and we think we know, but we don’t always revisit basic concepts and see how we can enhance them.
Now, my experience in emergency medicine, I’ve already told you that I’ve worked a ton in emergency medicine, but I’ve also worked in the ICU. I’ve also worked with Swan-Ganz catheters and was able to do clinical assessments and look at the metrics and the numbers from a Swan Ganz. How do the vital signs in the ICU translate to when you first assess a patient? That’s what this post is going to be about, vital signs.
First and foremost, wherever you’re embracing this content from, I want to ask you a couple questions right now, and I want you to come up with the answers in your head. I want to know, how much do you trust your vital signs? How much do you trust them? Let’s go through each one of them.
- Temp, your temp. If a nurse brings you a temp of 98.6, on a scale from one to 10, how confident are you in that?
- How about a pulse? On a scale from one to ten, how confident are you in a pulse?
- Blood pressure? On a scale from one to ten, how confident are you?
- How about a respiratory rate?
- How about an O2 sat?
Now, any good clinician needs to be very skeptical of all vital signs. We have to always know we’re dealing with imperfect data, and a good clinician is going to weigh out how imperfect is it. What’s the risks versus benefits? What’s the probability?
How sure are you that a temp of 98.6 is valid? Now, if you asked me that generally, I’d say on a scale from one to ten, I think it’s probably about a six. Pretty low confidence. You know why? Because I don’t know how the temp was taken. I just don’t know. If it’s a tympanic temp, my confidence in this is about a six. If it’s a temporal temp, where they put the probe over the forehead, I have no idea on how good those are. Probably they’re a six, maybe even less, because I just don’t have any confidence. If it’s oral, probably an eight, but kids can have a tough time.
Geriatrics with dementia who don’t close their lips around the probe, that can give me a false low temp. I’ve been burned by that. Be very careful about demented people in getting their temperature, because if they don’t keep their mouth closed around the probe, and if they come in with shortness of breath, you can easily go down a CHF pathway when it’s really pneumonia.
The biggest thing that makes us trigger infectious diseases is typically the temp. That’s the first thing we come to. If you have someone who’s short of breath with a temp of 103, your job is relatively easy. If you have someone who is short of breath and they got a normal temp, if you go down the CHF pathway and you think it’s failure, which I’ve done, and you squirt them with Lasix and they really have pneumonia, you just took that pus that’s in the lung and made it more concentrated. That’s sinister. Rectal temp is the gold standard. That’s a 10 to me.
Pulse and Blood Pressure
What about a pulse? How sure am I of a pulse? Now, pulse, I’m pretty confident. Normally it’s a machine generated pulse. I’d say my confidence of a pulse is probably 8.5. It’s pretty high. Have I ever been fooled by a pulse? Well, the only time is if you have a rapid atrial fibrillation and you do a radial pulse, that pulse can look slow. But when you put them on the monitor they’re really running at a buck-fifty. That’s the only time that I’ve been fooled by a pulse.
What about blood pressure? Blood pressure, you can get a lot of falsely weird blood pressures. If you use too small of a cuff on too big of an arm, you’re going to have a falsely high blood pressure. If you use too big of a cuff, it won’t be falsely low, it’s just going to be laborious to pump up. Often times I get falsely low blood pressures. Not uncommon from EMS, and I think it has to do with them being on the back of a rig. They can’t quite hear the systolic or diastolic pressure, so they report one out because they kind of think they hear it, when they’re in a suboptimal environment. Maybe their stethoscope isn’t very good, or it’s tough to hear in the back of a rig.
I do know though when I feel a radial pulse and I can palpate it, that’s pretty reassuring that I have a systolic pressure that’s normally sustainable to life. I’m going to say that again. They talk about core blood pressures between radial, carotid and femoral, each one of them having a slightly different systolic pressure reading. If you have a radial pulse and they’re perfusing their hand, there’s a really good chance they’re perfusing their kidneys. That’s a very good sign to me. I use that pulse as a crude feel for blood pressure.
Let’s go to blood pressure now. How sure am I that the blood pressure is accurate? I would say probably a little bit less than the pulse. I’d say probably a 7.5, 8.
I want to make you aware of something, and this is kind of high end. If you are embracing this content, you’re probably going to have to study this a few times. Think of systolic pressure as synonymous with cardiac output. Now, if systolic pressure is low, you should think cardiac output is low. That’s very reasonable. If you have someone who’s hypotensive from a systolic perspective, they’re not going to be perfusing their brain, their heart and their kidneys. They’re most likely going into shock.
That diastolic pressure is where things get interesting. Diastolic blood pressure is driven by epinephrine. If you have someone who’s in hypovolemic shock, they bled out due to GI bleed or trauma, their systolic pressure is low. The systolic pressure is 80, but their adrenal gland is going absolutely berserk. It’s hyper-secreting epinephrine. They’re going to be hyper-sympathetic, because epinephrine’s up and epinephrine drives diastolic pressure. If you have someone in hypovolemic shock, you’re going to have a systolic pressure of 80, diastolic is going to be about 70. Very narrow pulse pressure.
Now, if you have someone who has problem with shock that makes their blood vessels abnormally dilated, that happens with things like sepsis or anaphylaxis, their diastolic going to be really low. Cardiac output’s going to be 80 and diastolic is going to be 30. How do we treat anaphylactic shock? Epi. We have to drive up that diastolic pressure. The best way to absolutely monitor for shock though is going to be urine output. Remember that. That’s important. There were times as a hospitalist or working in the ER where I had someone for a prolonged period of time, and I wasn’t sure if they were really going into shock. Remember, shock is inadequate tissue perfusion. If they’re acutely in shock, they’re not going to perfuse their brain. Hypotension and altered mental status is synonymous with shock. You should always think that way as a clinician.
With a subtle onset of shock, they’re not going to perfuse their kidneys well. That’s when you have to put a Foley catheter in, then throw out the urine that you get out. I don’t care how much urine’s in their bladder. I want to know how much urine are they making. An adult should make about half a cc per kilo per hour. I’m a 100 kilo guy, so I should be making about 50 ccs of urine per hours. Every two hours, making about 100 ccs of urine. If so, that means that I’m adequately perfusing my body well. If that starts dropping much below that, that means that I’m going into shock. Some shocks come on gradual, like sepsis. That’s twice as much in a child. A child’s urine output should be 1 cc per kilo per hour. Overall, blood pressure, I feel less confident in that then I do my pulse.
Now, respiratory rate, two. It’s two. You have well-meaning nursing staff who, they put down 16 for their respiratory rate. Why? It’s a heuristic. It’s a mental shortcut. Someone comes in with a sprained ankle, respiratory rate is absolutely invalid. I don’t care about that. So, they get into a habit very often of just writing 16 down.
Here’s the golden rule about respiratory rates. No respiratory rate is valid unless you take it yourself. When is that really important? It’s really important to tell me if I have a patient who’s laborious and they really have a pulmonary problem like asthma, COPD, pneumonia or CHF. But, it’s imperative to know the respiratory when it comes a metabolic acidosis. Because if you have someone who’s in a metabolic acidosis, they’re going to be tachypneic. They’re going to be breathing fast and that’s called Kussmaul breathing.
When I walk into a room of a patient who has diabetes, if they’re breathing at 32, I have to ask the question, “Could they be in a metabolic acidosis?” Or someone with a renal failure, if they’re breathing at 32, I have to ask, “Why are they breathing so fast? Are they Kussmauling?” We talked about this is depth on the acid-base portion of Talk EM Podcast. So, if this is a little elusive to you, I would challenge you to go back and listen to that podcast.
O2 saturation, how confident am I in that? When you look at the waveform, if you have a really good waveform for your pulse oximetry, it’s pretty valid. Can you be fooled? Well, you can be fooled by anything in medicine. You always have to keep your mind open.Look at carbon monoxide poisoning or methhemoglobinemia that goes with G6PD deficiency in a crisis. It’ll saturate the hemoglobin molecule; therefore, it’s being read as 100% saturated. It’s just not saturated with oxygen. It’s saturated with something else.
Always question your vital signs. You need to know how dependable your vital signs are, the source of your vital signs, and anytime you see a sick patient, you have to question them. Are they valid?
When I walk into a room of a variable, an unknown, I don’t know what’s going on with them. Or, I’ve responded four times to inflight emergencies, where I’ve been on medical mission trips and we just didn’t have the resources. I worked on the ambulance where we were pretty rural, so we didn’t have a lot of backup. I wasn’t an advanced clinician at the time. I was a basic EMT, so you had to get really good with fundamentals.
One of the things that I would do when I initially assessed a patient is I’d put my hand out to shake their hand. If they can shake my hand, that tells me a lot. They’re probably relatively stable if they can shake my hand. That’s a very basic test. Another basic test I do right there, bedside or patient side, is hold up two fingers and say, “Am I holding up four fingers?” If they are able to say, “No, you’re holding up two fingers.” That tells me a lot about their mentation and their cognitive function.
Right after I go to extend my hand, if they shake my hand, it tells me a lot. If they don’t shake my hand, that’s immediately when I go to the radial pulse. I will immediately be able to tell a lot of things from that. Are they tachy or brady? I’ve felt so many radial pulses that I go, “Ooh, this person’s fast.” “Ooh, this one’s brady.” If I can feel the pulse, it tells me something about the systolic pressure, and often times when I touch them, their skin gives me hints. Are they cool and clammy? Are they hot and sweaty? If they feel a little warm, I trust my physical exam. I’ll then take my hands and put them up on their neck. I feel very good about picking up a qualitative fever, just by my physical exam. I challenge you to start doing them as well.
This very well could be perceived as a very basic lecture on just vital signs, but you have to know how to use them with patient care. My hope is that we brought you a little closer from some of the basic information to a little more clinical information.
Thank you for joining us today on Talk EM, where our whole goal is promoting clinical excellence, targeting advanced practitioners.