Tag Archives: BLS

Waveform Capnography Part 3

Wow, it’s been a LOOOOOOONG time since I visited this category. Sorry for taking so long with Part 3, if you need to knock the cobwebs out of what I’ve written on this topic in the past here is Part 1 and Part 2.

Ok, so what did I promise you the last time? Oh yes, patterns in different respiratory issues.

So the last time we talked about this we played with the normal pattern for a ETCO2 waveform, which is the equivalent of a plateau with fairly sharp delineations between phases and the normal values of exhaled CO2 being between 35-47 mmHg. So now that we’ve established what “normal” is, let’s look at some things that aren’t normal.

Abnormally High Numbers and Funny Looking Waves

“Hey RJ, the numbers were like 50 mmHg and up the last time I used capnography!’

High numbers indicate CO2 retention (bonus question: which is common found in what respiratory condition?) which means that the patient isn’t moving any CO2. You can fix this with mechanical means such as a BVM or CPAP (if the assessment indicates obstructive
pulmonary disorders) or if the respiratory depth is adequate, you can try using a non-rebreather mask.

I will tell a story. When I was a medic student riding at Xenia Township in Ohio, we responded to a report of an unconscious female out in the sticks. On arrival, we found a 60-some odd female lying on her couch. She was obtunded, with questionable pupil size, normal blood glucose, depressed respiratory drive, sinus rhythm, normal 12 lead ECG, and a slightly elevated blood pressure. We expedited her transport, and we couldn’t wake her up despite the use of naloxone (we suspected she had overdosed on recently prescribed pain medication) and a questionable CVA screen. Turns out, it was none of the above. Had we placed a capnography probe we would have found her PETCO2 to be in the 60-80 mmHg range and could have corrected her mental status change using mechanical ventilation.

Why tell you this? Because the technology was brand new to EMS then (it was a new feature on our recently upgraded LifePak 12’s) and if we had dug a little deeper we would have found COPD in her history, specifically chronic bronchitis. We could in-lined a breathing treatment through the BVM and created positive pressure in her alveoli and open them up, creating the release of trapped air and bringing her back to normal level. The next time we encountered her with the same issue (which was about 3 months later) I knew exactly how to correct her problem. 80% of all diagnosis is history related (and we do diagnose, don’t get me started) so make sure your history is as complete as the situation allows.

In bronchospasm (which is a form of pulmonary obstruction), the waveform, when analyzed closely, may look like something of a shark fin. Why is that?

Well, the Expiration phase (which is the Phase I and II waves) is prolonged due to obstruction. This makes the wave kind of smooth out a bit as the patient attempts to force air through the obstruction. This patient may exhibit the classic respiratory distress signs such as tripoding, nasing flaring, etc, and will appear in trouble before you even put the probe on. As you remember, those breathing patterned are typical when the patient is attempting to increase the PEEP (positive end expiratory pressure) in response to air trapping.

I’ve also seen the numbers high in a post arrest in the presence of DKA, the science indicates that PETCO2 is an accurate measurement even for regular patients in DKA for PCO2, which can help you determine if DKA is present.

This is kind of a quick end to a long standing series but I wanted to put out an ending like I had promised so long ago.





FLASHBACK – Influenza Case Study

As flu season hits hard, you should remember what it is exactly we are supposed to do for flu patients, and how to protect yourself.

Here, this post from December of 2010 should help…

The Scenario

The day drags on after that first cup of coffee, and seemingly slows down after the second. Waking up is always a hard thing to do, especially when you don’t have that period to ease into your day.

Which is why you’re grumbling at the at the MDT screen on your way to a very early call, the first of your shift, and you haven’t even had a chance to see what destruction lay behind the doors of the box, inflicted by a very tired but well meaning off-going shift. You scan the screen for a glint of additional information beyond the “twenty six alpha one” you read in the code box.

A “26A1″, you know, is a standard sick call, a non-emergency response to what has been prioritized as non-emergency. Sometimes the dispatchers get it wrong (either because they don’t ask all the questions or the caller doesn’t give much help, you usually decide which on the scene), but it is fairly accurate MOST of the time.

The ambulance rounds another corner in the quiet neighborhood, the morning dew settled on all the car windows and a slight haze appears on the horizon. The EMT scans the addresses on his side while you scan for numbers on yours. “What’s the numbers again?” he asks.

“2114,” you reply.

“I wish they would put numbers where we could actually read them.”

“2013… your side about a block up.”

The ambulance drifts to the left side of the street and the scanning begins again. After a few minutes, a young African American girl appears out of a front door and begins flailing her arms in the air. “We see you, we see you, you don’t need to be crazy,” the driver comments and the ambulance pulls to a stop just past the incline into the driveway.

“Unit fifteen, on the scene.”

“Check unit fifteen, zero six thirty eight,” the dispatcher replies. Must looking to be a long morning for her, too.

You roll out of the cab with your radio, sliding the clip into your pocket so it hangs on your leg and jerk the handle to the ALS compartment and produce a blue trauma bag. Pulling on some gloves, you walk up to the door and slowly pull it open. Not a person in sight.

“Fire department!” you yell as you cautiously make your way into the front room. Your radio comes crackles as the dispatcher calls out unit twenty three, also in your battalion, to make a call on the other side of your territory, this time for a cardiac arrest. You sigh. This is going to be a long day.

A voice calls out from a hallway to your right. “Back here! It’s my daughter, she just throwed up and been runnin’ out for hours.”

Your partner shoots you one of those “you have gotta be kidding me” looks, to which you shrug in reply.

You find your patient, a seventeen year old girl, slumped over a toilet. She is dry heaving and getting up only that white foamy stuff that comes out when you have nothing left to vomit up.

“When did this start?” you ask, usually your first line question, behind “what’s going on?” or “what made you call for an ambulance?”

“‘Bout three this mornin’. She throwed up early and whenever she tries to drank somethin’ she throwed it up too.”

The differential list runs through your mind, and the work begins to narrow down the causes to a select few, but based on the presentation, the list is short.

“And she’s had diarrhea as well?” The pale looking girl nods in the affirmative, and you place the back of your ungloved wrist on her forehead, then begin a more focused assessment. You seat the girl on the toilet, as you reach into the bag and produce a thermometer while your partner pulls out your blood pressure cuff and stethoscope. The thermometer goes into her mouth, while you count the pulse rate.

“One thirty four over eighty six, heart rate sounds rapid” your partner reports. You scribble this down on a piece of paper when the thermometer starts beeping at you.

“One zero three point six” you say as you scribble it down in addition to the patient’s name, age, social security number, birthday, and phone number.

The heart rate is counted around 130. Lung sounds are clear with a dry cough, and the patients reports minor abdominal discomfort, a combination of nausea and muscle soreness, and rates it at a 5 out of a 10 pain scale.

“Have you been having chills, headache, or muscle aches or cramps?” you question.

“Yes, all of those.” the girl answers.

“Sounds like you have the flu, have you taken any over the counter medication? Like Tylenol or ibuprofen.”

“No, just started last night,” mother replies.

“Would you like to go to the hospital?”


Influenza is a nasty virus, and can be contracted from a number of sources, typically through inhalation of droplets from the cough or sneeze of an infected person, this is known as droplet exposure. It can be very resilient and the only thing that can be done is let it run it’s course.

Influenza belongs to a set of RNA viruses family Orthomyxoviridae. Unlike cells, the virus does not have DNA, and it relies on host cells to replicate it’s RNA strand, and it does so in a very ruthless way, here’s how it works:

  1. A viron (virus RNA) binds to sailic acid on the surface of a host cell through hemagglutinin (the virus causes blood proteins to bind with it). This is typically done to the epithelial cells of the nose, throat, and lungs.
  2. The blood cells are removed from the virus by a protease (breaks down proteins) and is allowed to enter the cell through endocytosis (allows the cell to absorb molecules)
  3. The RNA chain of the virus enters the nucleus of the cell and “rewrites” the instructions that the nucleus provides to the cell.
  4. The cell begins producing viral proteins, some of which are secreted to the cell surface, and others are returned to the nucleus to assemble a viron. The viron leaves the cell through bulge of proteins on the cell surface.
  5. Once the viron is released, the cell dies.

So that you know how it works, how does this apply in the pre-hospital?

The most common symptoms of the disease are chills, fever, sore throat, muscle pains, severe headache, coughing, weakness and general discomfort. If you suspect the flu, you should ask these questions, but they may not all be present at once, so a good recent medical history is an important part of a correct diagnosis. Pay attention to duration of onset for fever and length of fever, if the fever has only been noticed within a few hours, it is generally not dangerous. When it has been allowed to continue unchecked for several days, or has been increasing, it is a medical emergency. May produce nausea and vomiting, as well as diarrhea, most often EMS clinicians are presented with these complaints, but you should not rule out other causes such as food poisoning or other acute abdominal conditions.

This table illustrates the likelihood of influenza infection when presented with common complaints:

Symptom:                    sensitivity        specificity

Fever                                      68-86%                  25-73%

Cough                                     84-98%                   7-29%

Nasal congestion               68–91%                 19–41%

Source: Call S, Vollenweider M, Hornung C, Simel D, McKinney W (2005). “Does this patient have influenza?”. JAMA 293 (8): 987–97

I gotta feva, and the only prescription is… well, available “OTC”

Fevers are a natural inflammatory response to infection, and can cause thermoregulatory problems including shivering as hypothermia is perceived by the brain and it begins active rewarming as well as making the patient feel the need to “bundle up.”

Hyperpyrexia is defined as an oral or axillary temperature greater than 104 or a rectal temperature greater than 106 and can cause brain damage, and prolonged fever and resulting dehydration is dangerous, resulting in cellular damage. This will literally “cook” the brain. If you have ever hardboiled an egg and just left the heat on high and let the water boil away, yeah, same effect. Patients that have had an unchecked fever for days and are hyperpyrexic may require active cooling using ice packs depending on medical control, aggressive airway management, and lots of IV fluids as they will be extremely dehydrated.

Patients presenting with flu symptoms rarely require transport, unless it has progressed to where the patient is neurologically or hemodynamically unstable.

Advise patients with flu symptoms to:

  • Stay at home
  • Get plenty of rest
  • Drink a lot of liquids (electrolyte solutions of water and sports drinks)
  • Do not smoke or drink alcohol
  • Consider over-the-counter medications to relieve flu symptoms (not ASPIRIN)
  • Consult a physician early on for best possible treatment
  • Remain alert for emergency warning signs

Warning signs are symptoms that indicate that the disease is becoming serious and needs immediate medical attention. These include:

  • Difficulty breathing or shortness of breath
  • Pain or pressure in the chest or abdomen
  • Dizziness
  • Confusion
  • Severe or persistent vomiting

Source: http://en.wikipedia.org/wiki/Influenza_treatment

Fluid therapy may be necessary if patient is unable to properly take on liquids or has had a persistent mild fever (100-102 oral) as dehydration caused by this is dangerous. Passive cooling measures (exposing the patient, cold packs or wet cloths) should be used whenever possible during transport of a stable influenza patient. Avoid rapid cooling as this may cause seizures. Consider anti-emetics during transport to suppress nausea and reduce vomiting.

Remember to get your flu shots, and if the patient is vomiting or coughing you should wear a mask to prevent inhalation of those droplets.

Methodist Healthcare Neuro Symposium

This week has been a whirlwind of activity. I’ve been working the Monday, Wednesday, and Friday schedule this rotation and in between I’ve been educating myself. Well, refreshing and educating. I went to a module of the Fire Department’s National Registry refresher, and today I went to a stroke and neurological care symposium put on by Methodist Healthcare here in Memphis. Had a great time.

Our medical director, Joe Holley, gave a little update on the progress and updates of the new stroke guidelines. I was interested in the new guidelines for stroke care involving some issues I have pushed a reasoned out for years. The first concept was that for hypoglycemia presenting in in an acute stroke that we shouldn’t be blasting the blood sugar around with D50. The sudden increase followed by sudden drop in blood glucose is actually associated with worse outcomes. I’ve been pushing for a re-write of our hypoglycemia protocol for a while that would eliminate D50 from the protocol and replace it with 500cc of D5W, which will deliver the same amount of glucose as a 50cc carpuject of D50. I will write more on this later.

He also hit on not giving aspirin to stroke patients, which I never did anyways regardless. He also talked about something that I want to write on more in depth later, which was managing hypertension in the acute stroke presentation. The primary reasoning I’ve always thought was that the body is trying to perfuse the brain, and you can cause way more damage by taking away the reflex than worrying about a hypertensive crisis. I’d say get rid of a protocol for hypertensive crisis in the EMS setting (unless we were using Labetalol, but I digress) especially here because it seems that EVERYONE is on anti-hypertensives.

James Roberts followed Dr Holley, presenting on the Cincinnati (FAST) stroke exam vs the MEND. MEND meaning Miami Emergency Neurological Deficit exam. I like the MEND mainly because it is specific and detailed, but they recommend using the FAST to quickly screen patients because the FAST, when only 1 of the 3 signs is present, is accurate 72% of the time. By comparison, the hospitals misdiagnose stroke 25% of the time, so it’s accuracy is generally unmatched. In EMS we tend towards things that are quick, easy, and memorable, so as a screening exam FAST is unmatched. I will write more on it later as well.

Dr Marc Grossman from Miami-Dade Fire Rescue gave a presentation about how they improved survivability in stroke patients in Miami, which has been wildly successful. I think that sometimes our issue with establishing true success is that getting information on outcomes from the hospitals is like trying to rob a bank. You can try, and you may even succeed once, but the chances of getting a return diminish quickly. It seems to me at the street level that we only get back a lot of feedback on patients where we either screwed up really big (because hospitals never make mistakes) or the outcome makes them look really good.

Something new were breakout sessions, where we got to take a look at how they coil an aneurysm, how all the imaging is done (similar to a CATH lab), some information of how congenital defects are corrected and some new medications out on the market. All of it looks very promising.

“Neurosurgical Emergencies for the EMT” was then presented by Dr. Stephanie Einhaus. This was mainly a lecture over how the neurosurgeons work on different types of brain problems and also some information on a new Tennessee state law regarding brain injuries in athletes, that a neurologist or a physician has to clear an athlete to play after they have had a brain injury. The wording of the law seemed to present that it was any brain injury on the field in order to prevent secondary injury.

The Stroke Coordinator at Methodist Healthcare, Jennifer Phillips, RN, explained information that the hospital has researched regarding strokes that resulted from head bleeds, and that number was fairly low. I held a question when she was discussing treatment and symptoms regarding the corelation of capnography to maintaining proper cebral pressure, but I will write more on it later.

Lunch was awesome, thanks Kim.

It seemed that during this symposium there were a lot of people from Alabama, and keeping with that, Anne Alexandrov, a “nurse doctor,” presented on thrombolysis. The United States was the first country in the world to approve the use of tPA in acute strokes and since then we are dead last in the industrialized world using this medication in stroke. What she found while researching hospitals was that a lot of hospitals create extra excuses to not use tPA, and as a result a lot of patients that might benefit from it go untreated. She explained that chemotherapy has a 50% complication rate (I know this personally, being a former cancer patient), but you never hear oncologists tell patients that they are better off with cancer, so why when tPA has a lower complication rate do neurologists not use it?

I likened the concept to us in EMS, that we make up a lot of excuses, either it’s bred culturally or created by policy within the organization, that we don’t treat certain kinds of acute pain or painful injuries with narcotics or pain controlling/eliminating medications. Those are what I like to call “wrong.” People call us for (among other things) pain, so shouldn’t we be in the business of treating and managing acute pain? Just a thought to hang your hat on for a while.

Anyway, overall, I had a great time and if you were following my Twitter feed you certainly had a few laughs. Hopefully I will be presenting at one sometime (…ahem) and someone else can write about me!

Sweeping up the C.R.U.M.s

Few phrases get my blood going like “we’ve always done it this way.”

Seriously, find me at a conference and tell me that something new is a bad idea because how it has always been done works just because it does.

Better yet don’t do that, because you will get me all ranty.

I’ve been pushing back a lot against that train of thought lately, it mainly stems from logistical issues that we have been facing, but today it stemmed into a related clinical area. I was basically told that we need to have thousands of liters if IV fluid because we won’t have enough if we get a trauma patient.

Are you serious? The most you should ever be hanging on a trauma patient is 2 bags at a time and we rarely, if ever, hang a bag of fluid on someone anyway in the course of a normal day just simply because they don’t need it. We could theoretically put 4-1000 mL bags on the ambulance and leave them there until they expire at our current rate of consumption, so how can you stand there and in good conscience tell me we need more on the off chance we will get someone who needs that much.

I debated a trainee (I wondered why I was debating a trainee, but we trained him to think and act this way, so I am partially to blame) the other day about the new BD Insyte AutoGard BC (Blood Control) IV catheters we will be getting soon (another project I am seeing come to fruition after a co-worker got a needle stick from a supposedly safe needle) about the necessity of getting blood glucose readings and the accuracy of the meters with venous vs capillary blood. His argument was that venous blood is more accurate and we should draw it from the flash chamber of the IV catheter or from the needle hub. The reasoning behind this is that we are sticking them unnecessarily.

I countered that the manufacturer builds the equipment to perform at certain specifications at certain parameters, and that using the equipment in a manner not intended will not give accurate readings. “But we’ve always done it this way” was the gist of his reply. Luckily I have some sway over his opinion at the moment, so I am still able to plant seeds that will hopefully blossom correctly later into an “aha!” moment.

Gosh, I got ranty.

Anyway, each organization has personnel that either have been on long enough to be stuck in their ways or too young in the practice to know any better. I have developed a term for the first: C.R.U.M… or

Change Resistance Unswayable Medic

Like the crumbs left over after a very bready sandwich, these are the leftovers of an era when the rest of the organization moves on. They rely purely on anecdote and luck, calling both “experience” and failing to update skills and knowledge, and using both to trounce any word against them as being incorrect or to attempt to discredit anything new that threaten their existence.

As Steve Whitehead says “medicine moves fast… keep up” and these are off the mark and way behind. The CRUMs are easily spotted using the phrase “this is how we’ve always done” or “this always works because I’ve seen it work” some similar defense as a last ditch effort to resist the research and study that contradicts their position.

My charge to you is to convert your CRUMs, kicking and screaming if you have to, into the fold. Don’t let a brother drown!

Rise of the Battalion Trainer

I’ve always been an advocate for EMS education, not necessarily training (or if the new standards are to be considered, then below the level of Paramedic it’s still considered “training” in my mind) and I’ve been a mechanism for access to education within my own personal sphere of influence. I can’t believe how many times I’ve sent people to Tom Bouthillet’s blog or some other blog that’s had a significant impact on spreading the word as it were.

When I first moved to Memphis, the education system was very formal and extremely centralized. I predicted (accurately, I might add) that the day is coming where there would be too few staff to deliver the training and education that, as an EMS providing organization, we would need in order to provide the access to advanced skills and to practice those skills. I thought that the Field Training Officer program would have done enough of that, expanding the role of a few FTO’s to train everyone else. Once again, thanks to budget cuts, we have made changes to the FTO program that I don’t necessarily agree with, but the alternative was far worse.

So, decentralization of the education system is underway. Volunteers have been solicited for the formation of a corps of field personnel to become educators in the field, with content delivered on the spot. This essentially reduces or eliminates the load on training center staff to produce training for field personnel, allowing them to focus on educating the students in our paramedic program and our recruits becoming Basic and Advanced EMT’s.

Incentives offered to personnel that volunteered included CEU’s every year for refresher training AND teaching hours that apply towards Tennessee Instructor Coordinator and Associate Instructor.

Yes, I volunteered.

The Art of the Narrative

I was jogged back into training mode the other day by a trainee (and a supervisor) when we were discussing narratives. While I feel that his presentation of a patient care report was a bit dramatic and over-reaching, I think it’s something that may need to be touched upon while the thought is in my head.

What exactly does the narrative do for us in a patient care report?

It is written that a narrative completes the permanent record of a patient contact.

My take is that it provides details about the contact that otherwise were not available in other parts of the report. It functions as an overall summary of the contact and findings noted in the report. When instructing trainees or students how to write narratives, I start with the two standard formats that I was taught as a young padawan.

The first was SOAP

  • Subjective
  • Objective
  • Assessment
  • Plan

I remember this format in a way that when I’m writing in this format it is always “what I’m told, what I see, what I examined and how, and what I did about it.” It’s not my favorite format mainly because a lot of times I gather history from places other than what the patient tells me because often the patient doesn’t even know their own history.

I prefer CHARxT

  • Chief Complaint
  • History
  • Assessment
  • (Rx) Treatment
  • Transport

I like this method because it allows me to meld different sources of history into one concise location. It makes no sense to me, when you mention history as in SOAP, that you make multiple notes from where you got all the history from. Examples include one source of past medical history (PMH) from the family (whom I usually ignore unless they sound like they know what they’re talking about) and the medications you have on hand that belong to the patient what they are saying conflicts. The weakness of this format is that cardiac arrests usually fall under both Treatment and Transport, so it gets a bit confusing unless you combine to two.

Basic Components

Each contact you document, SHOULD have at minimum 4 components and at maximum 5.

Those 5 are:

  • Patient Contact/Chief Complaint
  • History
  • Assessment
  • Treatment
  • Disposition (Treat and Release or Transport)

Patient Contact/Chief Complaint

This is where you contact the patient and figure out why they (or someone else) called 911. If grand-daughter called 911 because grandma was snoring very loudly and wouldn’t wake up, her words should be placed in DIRECT QUOTES. If JuneBug called because his arm felt numb after sleeping on it, what he tells you should be in DIRECT QUOTES. Are you getting the feeling that what the patient tells you should be in direct quotes?

Why direct quotes?

It highlights the best reason why you were there (as legitimate or ridiculous as it sounds) in the patient’s own words.

Other information about initial delays to contact like access delays, unsafe scenes/staging, language barriers, patient belligerency, etc, should go in this section.


You should SUMMARIZE patient history in this section. 80% of your initial working diagnosis and that of the hospital is based upon how well you gather history. Putting notes in about grandma’s toe jam and recent ingrown toe nail surgery isn’t that significant unless you are talking about possibly sepsis or a problem with that area. It may be significant in diabetics, but if grandma is otherwise healthy, usually not significant. Use your clinical judgement.


This section will include all of your medical findings. I always include a head-to-toe summation of findings similar to what the transcriptionists use with hospital summary of findings but in a paragraph format. I also put information in here about invasive findings like blood glucose levels and a detailed interpretation of 12 lead ECG’s and monitor showings. If the initial blood pressure was anything but within a “normal range” and requires some sort of intervention, then I include some vital signs here, but that’s not a usual occurrence.

Rx (Treatment)

This is all the stuff you did. IV starts should include the bore size and location as well as number of attempts, and intubations are the same way and should include information regarding the number of passes required, capnography findings, depth at the teeth, and so on.


How you ended the call is just as important as everything else. If you released the patient (with or without treatment) then you should note mentation and other competency proving items. If you transported, then you should include how you got them onto your cot/stretcher/pram/whatever you call it and to the ambulance, what happened on the way to the hospital, and information about the hand-off like how you got them off your bed. Notes on the patient’s condition en route and at transfer of care should also go here.

These are guidelines, and you should always follow what your organization orders you to do, but it will usually fall back to a basic diagram like what I have shown.

Stay Classy.

IV, O2, and Monitor

I get amused when I watch some bright eyed bushy tailed medic student or field trainee. The excitement to be moving into the fun phase, or the next career phase makes me a little happy to be their guide on the way to a higher level of being, assisting them in their transition from technician to clinician.

Then we get our first run.

Then that excitement fades a little.

I watch our competent, entry level paramedic deploy their skills for the first time which usually results in a rehash of an old saying they learned in school:

“IV, O2, monitor”

C’mere junior, let me tell you how this REALLY works…

It’s not really their fault though, some schools (all but one that I’ve seen) don’t teach clinical decision making starting with the basics first. They teach paramedic students paramedic stuff, and predictably they over-emphasize the ALS. But it’s not EVERY run that we use ALS skills, so should we be teaching paramedic students how to use basic skills?

I think so. I think that yes, even though paramedic students should have a strong foundation in the basic before becoming paramedics I realize that this is often not the case or even desirable by many organizations, paramedics should be strong EMT’s first.

In another thread, paramedics are often held to organizational standards or perceived standards (read “culture”) that promote over-kill, inappropriate treatments, or “cookie cutter” medicine that results when adherence to the protocol book is placed above good (and appropriate) care.

The primary cause of these situations is called “reduction of liability” but in the same line don’t see that when we make an attempt to reduce liability we cage effective providers and praise poor providers. Personally, my protocol compliance statistics suck, but I deliver excellent care. Does my stat reflect my care? No. Do I make mistakes. Of course.

Somehow though, as in any organization that attempts to reduce their liability, when quantifying what “quality care” is ineffective providers are often the highest in the statistics for compliance. Why?

IV, O2, and monitor

I’m getting at that we should get away from such instruction and actually raise our bar. I would say that we don’t teach to skill sheets which promote checklist medicine and give the knowledge of what certain procedures are and why they are necessary. If we are going to use skill sheets, we should rate skills that require a checklist and not starting it with “given a scenario…” Any person with a pulse can perform a trauma and medical assessment, they teach it in the most basic of CPR and first aid classes.

It takes a real clinician to prescribe a procedure and know why.

Waveform Capnography Part 1

It’s been a long time since I’ve posted anything instructional, and looking at the sheer size of the topic I decided to separate this into multiple posts just to over it all. This post will cover the basics of waveform capnography as well as some anatomy and respiratory physiology that is important to understand as you begin to interpret waveforms.

So what is capnography?

Simply, capnography is a measurement of exhaled CO2. We already did this previously with colorimetric CO2, however, unlike colorimetric monitoring, capnography is not affected by alcoholic beverages or other carbon dioxide producing agents that are exhaled. Also capnography does not take “a few breaths” in order to display a change in the measurement, the change is instant when being viewed on the monitor.

You should also keep in mind that capnography and oxygen saturation are two different measurements. spO2 measures “how much” oxygen is attached to the available hemoglobin. As you also know, spO2 is easily fooled by carbon monoxide as it bind with hemoglobin. The spO2 sensor will detect carboxyhemoglobin and only see that something is bound to the hemoglobin and give a false reading. For an in depth video on hemoglobin, check out this video

Capnography will also be an accurate indicator of perfusion and the effectiveness of your or their respiration or ventilation at the cellular level. This is due to several physiological processes that occur with respiration. It is important to know because it is vital to understanding exactly how capnography works, and diagnosing and treating respiratory problems and illnesses more effectively.

The first thing to understand about cellular respiration is that it takes several different actions working as one. It takes oxygen from the lungs, glucose from the liver, and in the body cells it takes insulin produced by the pancreas. Insulin acts as a transporter, carrying glucose into the cells from the bloodstream. Brain cells are the only cells in the body that use glucose directly from the bloodstream without needing insulin. This is because insulin can not cross the blood/brain barrier, which is why when the glucose level in the bloodstream drops confusion and neurological disruptions result until the glucose level is restored.

When you breathe in, oxygen and carbon dioxide exchange places at the capillary beds in the alveoli. The outgoing CO2 is waste product from the cells, which means that cellular metabolism is taking place. The membrane barrier in the alveoli is in fact so thin that it allows oxygen and carbon dioxide to diffuse at the molecular level using a pressure gradient. The oxygen is then picked up by the hemoglobin forming and carried to the cells. When it reaches a capillary, the barrier thins again allowing molecular exchange using the same pressure gradient. When measuring blood gases, there are several different terms used to express this function, PaCO2and PetCO2 are the most important.

PaCO2 is the partial pressure of CO2 in arterial blood. This number should be small and the PaCO2 actually serves many functions. Your brain regulates your breathing rate and blood pH by monitoring this. If the pH of your blood stream increases, this number will increase, which increases your respiratory rate and depth in an attempt to “blow off” the additional acid. You see this in active DKA patients, as it is a very early sign of acidosis.

PetCO2 is the partial pressure of CO2 at the end of expiration. This measures the concentration of the carbon dioxide in the alveoli as they empty. This is an important indicator of many different metabolic functions. The main ones we are interested in is cardiac output and and adequacy of ventilation. If cardiac output is low or ventilation is inadequate, the measurement will be low because carbon dioxide is not being exchanged at an adequate rate.

That’s enough physiology for now. In Part II we will begin covering the waveform, it’s parts, and how it relates to the physiology of respiration.


Kodali, Bhavani-Shankar. (June 2010). Capnography In Emergency Medicine – 1911. In Capnography. Retrieved from http://www.Capnography.com.

Case Study – Resuscitation of… Part 1

…The Rich and The Famous!

I saw this presentation years ago at a symposium in Dayton, OH, when I was a young Basic EMT presented by Peter Lazzara from the Chicago Fire Dept. It was a fun presentation, and really impressed some things I wanted to integrate into future presentations. So, in a change to Peter’s original presentation, take your steps into history as I present a case study very near and dear to Memphis…

The Assassination of Martin Luther King, Jr

Martin Luther King Jr was perhaps the most influencial civil rights leader of the last century. Not many school children these days know who Fredrick Douglass was or his contributions to the Union Civil War effort by pressuring Massachusetts into raising the first battalion of black soldiers or raising awareness of the plight of enslaved persons in Confederate states. They do, however, know about MLK Jr and his death in Memphis at the Lorraine Motel.

Dr. King arrived in Memphis during the ’68 sanitation worker strike which was quickly evolving into a low scale riot. In order to allow peaceful demonstrations to prevail, he arrived in Memphis in the afternoon of 3 April, 1968. Shortly thereafter, he delivered the famous “I’ve Been To The Mountaintop” speech and retired to the Lorraine Motel to make plans for the demonstration in the coming days.

Dr King stepped out onto the balcony of the 2nd floor of the Lorraine Motel with several others to go to dinner on 4 April 1968 and was shot in the face from long range by a large caliber rifle at approximately 1801.

An undercover police officer attempted to provide first aid while an ambulance was called. Dr King arrived at the St Joseph’s Hospital (which stood where St Jude Children’s Hospital stands today) 15 minutes after being wounded with a simple oxygen mask on his face. Despite the best efforts of the physicians, Dr King was pronounced dead at 1905 CST.

Injuries described at autopsy were extensive to the face and neck. The bullet entered his face on the right lateral face at the jawline, traversing his neck severing the carotid and destroying the spinal cord. The bullet finally came to a stop in his left shoulder blade.

Trauma care provided by the Memphis Fire Department in those days was basically rudimentary first aid care, but were we to transplant modern techniques into 1968…

“… respond to a 27D3G, report of a man shot at the Lorraine Motel…”

Engine 2 would be on top of this immediately as the Lorraine Motel is directly behind Station 2. Response for the initial ALS company after receiving the call would be about 2 minutes.

You’re on Engine 2. What are your initial priorities on the balcony at the Lorraine Motel, with the severely wounded Dr. King as your patient?

I won’t approve comments on the story until after I have published Part 2 to give everyone an equal chance