Dominican Trip - Things To Do

When I started as a paramedic, my preceptor told me to be successful as a paramedic; you need a big ego to be able to do what is asked of you. You need to be able to seize control of a scene, act decisively and with faith in your every decision. You need a big ego to be able to stare down death and defeat it.

Maybe that is why so many medics leave the field because they learn that they often can’t do what is asked of them. They can’t always beat death, they aren’t always sure of the decisions they make, and often, they aren’t even asked to fight death at all. Their more daily opponent is not trauma or cardiac arrest, but vomiting, back pain, mental illness, substance abuse and age. Instead of the Reaper they fight overburdened health care systems, and are rewarded not with medals and plaques and televised reunion picnics, but with their own back aches, bills and fear of growing insignificance.

I contend that to last as a paramedic you need to ditch your ego all together. You still need to take control of a scene and act decisively, but the manner in which you do so is different. You act not for yourself, but for the patient. You no longer need every eye on you, you don’t have to boast of the two lines running wide open, the digital intubation, or the number of times you shocked the patient and how you got all the way down the algorithm to bretiylium. You can still have tales of how you challenged death, but the tales that mean more to you now are how you calmed down the anxious patient, brought pain relief to the hurting, and held the hand of the lonely and said something to make them smile and feel cared about. You are as nice to the dialysis patient as you were to the bleeding girl entrapped in the car; you are as thorough with the cancer patient as you were with the man having the massive MI. You learn their names and you tell them yours.

No one makes the transition all the way or all the time. There are days when I am boastful, days when I am resentful, days when I let my frustrations flow, when I ignore my patient and mail in my performance – doing nothing more than taking them to the hospital and getting their billing information. But there are enough days now, when even if I don’t feel my medicine is challenged, when I lack the great dramatic story to tell that I still get satisfaction from simple human contact. That is why I am still out on these streets twelve full-time and mega-overtime years later.

I write all of this as a preface to tell you about my latest trip to the Dominican Republic as part of a surgical mission. This is the second year I have gone, and each time I have had much anxiety about what I would be asked to do. The first year was harder in that it was the unknown. I was the lone paramedic on a team of over thirty doctors, nurse anesthetists, and registered nurses. There was one EMT beside me. I did not want to be the one given the mop, even if it meant I could hand it to my EMT assistant and tell her to mop under my supervision. I wanted my profession and myself to be respected.

The first year with seven surgeons and four operating tables, we turned out to be very busy. I found many opportunities to get involved. Before the week was out my initial assignment of “We want you as a helper in the OR, but don’t touch the instruments, we don’t want anyone to get hurt,” turned into a valued role in the caring for patients both pre- and post-operatively, using all of my EMT skills from IV insertion to assessment and medicine administration as an equal to the nurses.

This year, due to the larger number of nurses and only two surgeons (one a resident) meaning fewer patients, I felt the same anxiety. Who’s going to get the mop? My anxiety was made worse when on arrival we found they had added numerous college student helpers and two more translators. I might not even get the mop nor be needed to translate? I might not have a purpose.

I was first assigned to triage new patients. But then on the first full day when the Spanish interpreter for pre-op fell sick, I was reassigned, spared to my way of thinking, and I spent a useful morning speaking Spanish and putting in IVs.

The next day when the other translator recovered I was back out in triage working with a nurse who not only knew more about assessing hernias than I did, but who was Cuban born and spoke flawless Spanish. Fortunately, we got along well, and developed a system where I met the patient’s on the benches in the hallway, got their names, dates of birth, addresses, and took their vitals and weighed and measured them before sending them into the room for her to obtain the full medical history. We were an awesome team.

But as the week went on and triage dwindled, my assignment was to the post-op area. There during the previous year, at times, I had handled the entire room on my own, at others with one or two other nurses. Now had to share with six other nurses and far fewer patients. My Spanish was often needed – at least until the Cuban nurse entered the room, when the other nurses no longer asked for me to translate or give discharge instructions. Often in fact I had to call the Cuban nurse to assist me in translating, which of course was all for the best for the patient.

One particularly slow early afternoon I was asked if I wanted to go back on the bus for lunch and I responded, sure I had nothing to do. I thought about my comment that afternoon when I returned to work, well-fed. Nothing to do. I was in a room with five patients and their families and while at times there were anywhere from one to six nurses in the room, some who wandered in an out, checking vitals or if meds were needed, I started to keep my eyes open. I saw one nurse in particular, who did more than just check vitals and give post op meds. She had an eye for the patient’s comfort. Let’s get this one off the hot paper sheets they came wrapped in from the OR, or let’s sit him up, he looks uncomfortable. It was the eye for the little detail.

Thom Dick, in his great book, People Care: Career Friendly Practices For Professional Care-Givers writes:

"People don't remember much about our medicine. But they do remember how we make them feel."

I have found that to be true. I started looking for the little thing -- getting a patient or a family member a cup of water, talking to them instead of sitting on an empty bed, making them more comfortable. The head nurse had me take care of two patients directly and I made certain I knew everything about them so when the doctors came by to check, I was not just reading what was written in the notes. I knew the patient and about their lives.

Most of the patients I had met while doing triage. I came to understand that I was, in a small but important way, the face of the project for many of them. I was the maitre d’, the man who had walked them into the door and promised access to the experts. I saw if I was not the one translating their discharge instructions (I sought out the Cuban nurse to make certain they understood everything,) I made certain I was there to say goodbye to them. I did fewer procedures this time* and gave less medicine, but I felt immensely valuable not so much to the team, but to the patients.

At the end of the week when we met as a group to talk about our experiences of the week, I said something similar to the above – how I learned there is never nothing to do. That is what I hope I have brought back to the United States with me. When what I need to do is done – my assessment, the IVs, the monitor, the 02, the medicine are done, I need to see what else there is do because there is always something else to do – talking to the patient, making them more comfortable, making them feel that they are not alone, that someone – that a paramedic – that all paramedics care about them. Each and every one of us is the face of our profession. We are the maitre d', as well as the chef and the dishwashers). Our job is to give our patients the best most painless experience possible during a difficult time.

***

I would like to talk about just one patient I had this week – an eighty year old gardener who had a had a hernia since childhood, a hernia so big you could see it through his clothes like he had shoved a football into his pants. He came in the middle of the week after the head surgeon had already said no more patients – we are booked full. We were just writing people passes for the next mission that was to come to a neighboring area in September. But we had the man with the hernia wait until the doctor was out of surgery. When the doctor saw him, he said, as he did of other people, "We have to add this man to the list." And we did.

I sat with the old man the in the post-op room. He had no family of his own. The woman who he gardened for came and sat with him. She told me how she had watched him all these years and how he had struggled with the hernia, what a miracle it was to see him now. He was discharged the next morning, but he didn’t want to leave, he kept shaking all of our hands. I’d catch him over and over looking down at his waist where the hernia used to be, then looking up at us and smiling. When we said goodbye, we embraced like old friends. He knew my name and I knew his.

Going on a medical mission to the Dominican is a great place to check your ego, to replenish the things that can make you a better medic and a better person. I know in the coming year, I will often fail to live up to the standards I would like to uphold, but I know I will still be out here trying.

For information on the organization and a trip calendar of future trips, go to:

Medical Ministry International

For my daily account of the trip go to:

Paramedic Journal: A Year on the Streets

*I did get to insert an LMA in the OR thanks to one of the nurse anesthetist swho showed how it was done (We may be getting them on our trucks soon) and also scrubbed in on a thyroid removal where the surgeon let me palpate the crico-thyroid membrane and the trachea after the incisions had been made and the neck opened up (Not a lot of room to put an airway through).

Medical Mission

I'm off on a Medical Mission to the Domminican Republic for eight days, so no new posts until the 28th of May.

Meetings

I went to my monthly regional educational and medical advisory meetings yesterday. I was able to get the committee to agree to issue protocols immediately to permit paramedics to start utlilzing some of the changes recommended by the new AHA guidleines, while waiting until January to implement others.

The immediate changes:

CPR

Place emphasis on continuous quality CPR, with compressions at a rate of 100 per minute, 1 1/2" to 2" deep, allowing full chest recoil. Try to keep compression interruptions to less than 10 seconds. Compress while charging. Compress while intubating if possible. Non-intubated patients should receive CPR at a rate of 30:2, intubated patients should receive continuous compressions.

Ventilations for patients in cardiac arrest should be no more than 8-10 per minutes with each ventilation lasting no more than 1 second and containing only enough tidal volume to make the chest rise. Intubated patients not in cardiac arrest should be ventilated at 10-12 per minute. Do not hyperventilate.

Defibrillation

Instead of three stacked shocks, use 1 shock at maximum setting. After shocking, immediately do 2 minutes of CPR before checking for rhythm.

Patients in ventricular fibrillation who have suffered an unwitnessed arrest or for whom response time is greater than 4 minutes should have 2 minutes of CPR prior to defibrillation.

Intubation

Patients in ventricular fibrillation may have intubation delayed.

A Combi-tube and an LMA are considered 1st line airways along with ET.

Traumatic arrests should be intubated en route to the hospital if at all.

Drugs may only be given down the ET tube if IV access or IO access is unavailable.

IO

Adults may receive IO provided the device used has FDA approval. IO access should only be obtained on patients in extremis.

Asystole/PEA

Pacing is no longer recommended in cardiac arrest.

Additional changes to regional protocols, as a result of the new AHA guidelines will be implanted with regular protocol updates scheduled for January 1, 2007.

***

The new guidelines were produced by the International Liaison Committee for Resuscitation, after comprehensive review of scientific evidence from published studies.

Research shows the CPR currently being performed results in excessive ventilations (which decreases cardiac output), frequent interruptions of compressions and chest compressions too shallow and slow to produce results.

Hyperventilation increases intrathoracic pressure, which inhibits venous return. Since venous return determines cardiac output, hyperventilation reduces cardiac output, causing reduced oxygenation.

The new guidelines are about maintaining blood flow. Push hard, push deep, allow the chest to fully recoil. Minimize interruptions. When compressions stop, blood flow stops. Do not hyperventilate. When a patient is hyperventilated blood flow is compromised.

The question of shocking or doing CPR first is related to the patient’s physiological state. In the first 4 minutes of ventricular fibrillation, the patient is in the “electrical phase” of arrest, during which time the body has adequate oxygen and energy stores, a normal PH, and is unlikely to have suffered heart damage. The science shows this phase responds best to electricity. Intubation is not the priority during the electrical phase.

During the next six minutes, the body is in the” circulatory phase.” The v-fib is now fine or absent. There is inadequate oxygen in the heart, inadequate energy, acidosis, and heart ischemia. Effective circulation is needed to deliver oxygen to the hypoxic tissues to improve chances of successful defibrillation. Evidence suggests defibrillation before CPR in this phase may be detrimental.

Know the phase of arrest your patient is in.

The Committee also passed a lights and sirens document I put together for them without more than a minute of discussion. I was amazed. Sometimes documents takes years to get passed.

LIGHTS AND SIREN USE

GUIDELINES

Ambulances should use emergency lights or sirens only when transporting or responding to a call involving a patient believed to need immediate medical intervention.

Patient Response

Ambulances should respond lights and sirens only when directed by their dispatch center based on EMD criteria. Should additional information suggesting that the call no longer merits a lights and sirens response be received by the dispatch center while the ambulance is enroute to the scene, the ambulance should be downgraded to nonlights and sirens mode.

Patient Transport:

The crew member responsible for patient care during transportation will advise the driver of the appropriate mode of transportation based upon the medical condition of the patient.

When transporting the patient, the need for immediate medical intervention should be beyond the capabilities of the ambulance crew using available supplies and equipment.

Such conditions include, but are not limited to:

1. Unstable airway or severe respiratory distress

2. Shock

3. Patient with anatomic or physiologic criteria for Level One Trauma Center

4. Acute Stroke within the last three hours

5. Status Epilepticus

6. ST Elevation MI

7. Cardiac arrest with persistent ventricular fibrillation, hypothermia, overdose/ or poisoning

When in doubt, contact medical control.

Mode of transport for interfacility transfers should be based upon the directions of the referring physician or medical control physician who provides the orders for patient care during the transport. Generally, interfacility transport patients have been stabilized to a point where the minimal time saved by L&S transport is not of importance to patient outcome.

Lights and sirens use should be documented and justified on the patient care report (e.g., “flail chest”, “systolic BP<90”,>

Notes: In most cases (up to 95% of EMS incidents), EMS personnel can stabilize the patient’s condition to a point where the small amount of time gained by L&S transport will not affect the patient’s medical condition or outcome. In previous studies and in most situations, L&S transport generally only decreases transport time by a couple of minutes or less.

The American Heart Association gives a class III recommendation to L&S transport of patients in cardiac arrest. A Class III indication is not helpful and is potentially harmful. Providing CPR during L&S transport may increase the risk for injury to EMS personnel.

Exceptions to these policies can be made under extraordinary circumstances (e.g., disaster conditions or a back log of high priority calls where the demand for EMS ambulances exceeds available resources). These exceptions should be documented.

(The above document was adapted from Pennsylvania Guidelines.)

I've been on these committees for several years now. While because the regional paramedic committee is no longer functioning, I am no longer the official paramedic representative, I go to all the meetings, and I have great input. I come from the street, I do my homework, and they listen to me, even if they don't always agree. We do get things done. Being a part of these committees is among the most rewarding part of being a paramedic.

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10 Things Every Paramedic Should Know About Capnography

Capnography is the vital sign of ventilation.

By tracking the carbon dioxide in a patient’s exhaled breath, capnography enables paramedics to objectively evaluate a patient’s ventilatory status (and indirectly circulatory and metabolic status), as the medics utilize their clinical judgement to assess and treat their patients.

Part One: The Science

Definitions:

Capnography – the measurement of carbon dioxide (CO2) in exhaled breath.

Capnometer – the numeric measurement of CO2.

Capnogram – the wave form.

End Tidal CO2 (ETCO2 or PetCO2) - the level of (partial pressure of) carbon dioxide released at end of expiration.

Oxygenation Versus Ventilation

Oxygenation is how we get oxygen to the tissue. Oxygen is inhaled into the lungs where gas exchange occurs at the capillary-alveolar membrane. Oxygen is transported to the tissues through the blood stream. Pulse oximetry measures oxygenation.

At the cellular level, oxygen and glucose combine to produce energy. Carbon dioxide, a waste product of this process (The Krebs cycle), diffuses into the blood.

Ventilation (the movement of air) is how we get rid of carbon dioxide. Carbon dioxide is carried back through the blood and exhaled by the lungs through the alveoli. Capnography measures ventilation.

Capnography versus Pulse Oximetry

Capnography provides an immediate picture of patient condition. Pulse oximetry is delayed. Hold your breath. Capnography will show immediate apnea, while pulse oximetry will show a high saturation for several minutes.



Circulation and Metabolism

While capnography is a direct measurement of ventilation in the lungs, it also indirectly measures metabolism and circulation. For example, an increased metabolism will increase the production of carbon dioxide increasing the ETCO2. A decrease in cardiac output will lower the delivery of carbon dioxide to the lungs decreasing the ETCO2.

“CO2 is the smoke from the flames of metabolism.”– Ray Fowler, M.D. Dallas, Street Doc’s Society

PaCO2 vs. PeTCO2

PaCO2= Partial Pressure of Carbon Dioxide in arterial blood gases. The PaCO2 is measured by drawing the ABGs, which also measure the arterial PH.

If ventilation and perfusion are stable PaCO2 should correlate to PetCO2.
In a study comparing PaCO2 and PetCO2 in 39 patients with severe asthma, the mean difference between PaCO2 and PetCO2 was 1.0 mm Hg, the median difference was 0 mm Hg. Only 2 patients were outside the 5 mg HG agreement (1-6, 1-12). -Jill Corbo, MD, et al, Concordance Between Capnography and Arterial Blood Gas Measurements of Carbon Dioxide in Acute Asthma, Annals of Emergency Medicine, October 2005

“Research has (also) shown good concordance...in patients with normal lung function, upper and lower airway disease, seizures, and diabetic ketoacidosis.” –ibid.

V/Q Mismatch

If ventilation or perfusion are unstable, a Ventilation/Perfusion (V/Q) mismatch can occur. This will alter the correlation between PaC02 and PetCO2.

This V/Q mismatch can be caused by blood shunting such as occurs during atelectasis (perfusing unventilated lung area) or by dead space in the lungs (Ventilating unperfused lung area) such as occurs with a pulmonary embolisim or hypovolemia.

Normal Capnography Values

ETCO2 35-45 mm Hg is the normal value for capnography. However, some experts say 30 mm HG - 43 mm Hg can be considered normal.

Cautions: Imperfect positioning of nasal cannula capnofilters may cause distorted readings. Unique nasal anatomy, obstructed nares and mouth breathers may skew results and/or require repositioning of cannula. Also, oxygen by mask may lower the reading by 10% or more.

Capnography Wave Form

The normal wave form appears as straight boxes on the monitor screen:



But the wave form appears more drawn out on the print out because the monitor screen is compressed time while the print out is in real time.



The capnogram wave form begins before exhalation and ends with inspiration. Breathing out comes before breathing in.



A to B is post inspiration/dead space exhalation, B is the start of alveolar exhalation, B-C is the exhalation upstroke where dead space gas mixes with lung gas, C-D is the continuation of exhalation, or the plateau(all the gas is alveolar now, rich in C02). D is the end-tidal value – the peak concentration, D-E is the inspiration washout.

Abnormal Values and Wave Forms

ETCO2 Less Than 35 mmHg = "Hyperventilation/Hypocapnia"
ETC02 Greater Than 45 mmHg = "Hypoventilation/Hypercapnia"

Caution:

“End Tidal CO2 reading without a waveform is like a heart rate without an ECG recording.” – Bob Page “Riding the Waves”

However, unlike ECGs, there are only a few capnography wave forms. The main abnormal ones -- hyperventilation, hypoventilation, esophageal intubation and obstructive airway/shark fin -- are described below.

Part Two: Clinical Uses of Capnography

1. Monitoring Ventilation

Capnography monitors patient ventilation, providing a breath by breath trend of respirations and an early warning system of impending respiratory crisis.

Hyperventilation

When a person hyperventilates, their CO2 goes down.



Hyperventilation can be caused by many factors from anxiety to bronchospasm to pulmonary embolus. Other reasons C02 may be low: cardiac arrest, decreased cardiac output, hypotension, cold, severe pulmonary edema.

Note: Ventilation equals tidal volume X respiratory rate. A patient taking in a large tidal volume can still hyperventilate with a normal respiratory rate just as a person with a small tidal volume can hypoventilate with a normal respiratory rate.

Hypoventilation

When a person hypoventilates, their CO2 goes up.



Hypoventilation can be caused by altered mental status such as overdose, sedation, intoxication, postictal states, head trauma, or stroke, or by a tiring CHF patient. Other reasons CO2 may be high: Increased cardiac output with increased breathing, fever, sepsis, pain, severe difficulty breathing, depressed respirations, chronic hypercapnia.

Some diseases may cause the CO2 to go down, then up, then down. (See asthma below).

Pay more attention to the ETCO2 trend than the actual number.

A steadily rising ETCO2 (as the patient begins to hypoventilate) can help a paramedic anticipate when a patient may soon require assisted ventilations or intubation.

Heroin Overdoses - Some EMS systems permit medics to administer narcan only to unresponsive patients with suspected opiate overdoses with respiratory rates less than 10. Monitoring ETCO2 provides a better gauge of ventilatory status than respiratory rate. ETCO2 will show a heroin overdose with a respiratory rate of 24 (with many shallow ineffective breaths) and an ETCO2 of 60 is more in need of arousal than a patient with a respiratory rate of 8, but an ETCO2 of 35.

2. Confirming, Maintaining , and Assisting Intubation

Continuous end-tidal CO2 monitoring can confirm a tracheal intubation. A good wave form indicating the presence of CO2 ensures the ET tube is in the trachea.




A 2005 study comparing field intubations that used continuous capnography to confirm intubations versus non-use showed zero unrecognized misplaced intubations in the monitoring group versus 23% misplaced tubes in the unmonitored group. -Silverstir, Annals of Emergency Medicine, May 2005

“When exhaled CO2 is detected (positive reading for CO2) in cardiac arrest, it is usually a reliable indicator of tube position in the trachea.” - The American Heart Association 2005 CPR and ECG Guidelines

Reasons ETCO2 is zero: The tube is in the esophagus.*


* True as a general rule, but may not hold for cases of greatly prolonged down time prior to initiation of CPR or cases of massive pulmonary embolism where blood flow to the lungs is completely blocked. Also, in patients in arrest, CPR is neccessary to generate a waveform.

Caution: In patients with a prolonged down time, the ETCO2 reading may be so low (sometimes less than 6mm HG) that some monitor's apnea alarms may go off even though the monitor is still providing an ETCO2 reading and a small wave form. If the apnea alarm goes off and you continue to bag without resistance and have equal lung sounds and negative epigatric sounds, do not automatically pull your tube. A small but distinct square wave form along with even a marginal EtCO2 reading is still verification the tube is in the trachea.

ETCO2 can also be used to assist in difficult intubations of spontaneously breathing patients.



Paramedics can attach the capnography filter to the ET tube prior to intubation and, in cases where it is difficult to visualize the chords, use the monitor to assist placement. This includes cases of nasal tracheal intubation.


You're out (missed the chords).



You're in.

Paramedics who utilize this method during cardiac arrests with cardiac compressions continuing while they intubate may see CPR oscillations on the monitor screen immediately upon intubating, replaced by larger wave forms once the ambu-bag has been attached and ventilations begun. The oscillations provide proof that compressions alone can produce some ventilation.



Note: You must still assess for equal lung sounds. Capnography cannot detect right main-stem intubations.

Capnography can also be used for combitubes and LMAs.

Paramedics should document their use of continuous ETCO2 monitoring and attach wave form strips to their PCRs. Print a strip on intubation, periodically during care and transport, and then just prior to moving the patient from your stretcher to the hospital table and then immediately after transfer. This will timestamp and document your tube as good.

Continuous Wave Form Capnography Versus Colorimetric Capnography

In colorimetric capnography a filter attached to an ET tube changes color from purple to yellow when it detects carbon dioxide. This device has several drawbacks when compared to waveform capnography. It is not continuous, has no waveform, no number, no alarms, is easily contaminated, is hard to read in dark, and can give false readings.

Paramedics should encourage their services to equip them with continuous wave form capnography.

3. Measuring Cardiac Output During CPR

Monitoring ETC02 measures cardiac output, thus monitoring ETCO2 is a good way to measure the effectiveness of CPR.

In 1978, Kalenda “reported a decrease in ETC02 as the person performing CPR fatigued, followed by an increase in ETCO2 as a new rescuer took over, presumably providing better chest compressions.” –Gravenstein, Capnography: Clinical Aspects, Cambridge Press, 2004

“Reductions in ETCO2 during CPR are associated with comparable reductions in cardiac output....The extent to which resuscitation maneuvers, especially precordial compression, maintain cardiac output may be more readily assessed by measurements of ETCO2 than palpation of arterial pulses.” -Max Weil, M.D., Cardiac Output and End-Tidal carbon dioxide, Critical Care Medicine, November 1985

With the new American Heart Association Guidelines calling for quality compressions ("push hard, push fast, push deep"), rescuers should switch places every two minutes. Set the monitor up so the compressors can view the ETCO2 readings as well as the ECG wave form generated by their compressions. Encourage them to keep the ETCO2 number up as high as possible.

Note: Patients with extended down times may have ETCO2 readings so low that quality of compressions will show little difference in the number.

Return of Spontaneous Circulation (ROSC)

ETCO2 can be the first sign of return of spontaneous circulation (ROSC). During a cardiac arrest, if you see the CO2 number shoot up, stop CPR and check for pulses.

End-tidal CO2 will often overshoot baseline values when circulation is restored due to carbon dioxide washout from the tissues.

A recent study found the ETCO2 shot up on average 13.5 mmHg with sudden ROSC before settling into a normal range.-Grmec S, Krizmaric M, Mally S, Kozelj A, Spindler M, Lesnik B.,Resuscitation. 2006 Dec 8




Note: Each bar represents 30 seconds.

“End-tidal CO2 monitoring during cardiac arrest is a safe and effective noninvasive indicator of cardiac output during CPR and may be an early indicator of ROSC in intubated patients.” - American Heart Association Guidelines 2005 CPR and ECG

Loss of Spontaneous Circulation

In a resuscitated patient, if you see the stabilized ETCO2 number significantly drop in a person with ROSC, immediately check pulses. You may have to restart CPR.

The graph below demonstrates three episodes of ROSC, followed by loss of circulation during a cardiac arrest:



4. End Tidal CO2 As Predictor of Resuscitation Outcome

End tidal CO2 monitoring can confirm the futility of resuscitation as well as forecast the likelihood of resuscitation.

"An end-tidal carbon dioxide level of 10 mmHg or less measured 20 minutes after the initiation of advanced cardiac life support accurately predicts death in patients with cardiac arrest associated with electrical activity but no pulse. Cardiopulmonary resuscitation may reasonably be terminated in such patients.” -Levine R, End-tidal Carbon Dioxide and Outcome of Out-of-Hospital Cardiac Arrest, New England Journal of Medicine, July 1997

Likewise, case studies have shown that patients with a high initial end tidal CO2 reading were more likely to be resuscitated than those who didn’t. The greater the initial value, the likelier the chance of a successful resuscitation.

“No patient who had an end-tidal carbon dioxide of level of less than 10 mm Hg survived. Conversely, in all 35 patients in whom spontaneous circulation was restored, end-tidal carbon dioxide rose to at least 18 mm Hg before the clinically detectable return of vital signs....The difference between survivors and nonsurvivors in 20 minute end-tidal carbon dioxide levels is dramatic and obvious.” – ibid.

“An ETCO2 value of 16 torr or less successfully discriminated between the survivors and the nonsurvivors in our study because no patient survived with an ETCO2 less than 16 torr. Our logistic regression model further showed that for every increase of 1 torr in ETCO2, the odds of surviving increased by 16%.” –Salen, Can Cardiac Sonography and Capnography Be Used Independently and in Combination to Predict Resuscitation Outcomes?, Academic Emergency Medicine, June 2001

Caution: While a low initial ETCO2 makes resuscitation less likely than a higher initial ETCO2, patients have been successfully resuscitated with an initial ETCO2 >10 mmHg.

Asphyxic Cardiac Arrest versus Primary Cardiac Arrest

Capnography can also be utilized to differentiate the nature of the cardiac arrest.

A 2003 study found that patients suffering from asphyxic arrest as opposed to primary cardiac arrest had significantly increased initial ETCO2 reading that came down within a minute. These high initial readings, caused by the buildup of carbon dioxide in the lungs while the nonbreathing/nonventilating patient's heart continued pump carbon dioxide to the lungs before the heart bradyed down to asystole, should come down within a minute. The ETCO2 values of asphyxic arrest patients then become prognostic of ROSC.-Grmec S, Lah K, Tusek-Bunc K,Crit Care. 2003 Dec

5. Monitoring Sedated Patients

Capnography should be used to monitor any patients receiving pain management or sedation (enough to alter their mental status) for evidence of hypoventilation and/or apnea.

In a 2006 published study of 60 patients undergoing sedation, in 14 of 17 patients who suffered acute respiratory events, ETCO2 monitoring flagged a problem before changes in SPO2 or observed changes in respiratory rate.

“End-tidal carbon dioxide monitoring of patients undergoing PSA detected many clinically significant acute respiratory events before standard ED monitoring practice did so. The majority of acute respiratory events noted in this trial occurred before changes in SP02 or observed hypoventilation and apnea.” - -Burton, Does End-Tidal Carbon Dioxide Monitoring Detect Respiratory Events Prior to Current Sedation Monitoring Practices, Academic Emergency Medicine, May 2006

In the graph below, the respiratory rate decreases as the ETCO2 rises, and the patient suffers apnea, all the while the SPO2 remains stable.



Note: Each bar represents thirty seconds.

Sedated, Intubated Patients

Capnography is also essential in sedated, intubated patients. A small notch in the wave form indicates the patient is beginning to arouse from sedation, starting to breathe on their own, and will need additional medication to prevent them from "bucking" the tube.

6. ETCO2 in Asthma, COPD, and CHF

End-tidal CO2 monitoring on non-intubated patients is an excellent way to assess the severity of Asthma/COPD, and the effectiveness of treatment. Bronchospasm will produce a characteristic “shark fin” wave form, as the patient has to struggle to exhale, creating a sloping “B-C” upstroke. The shape is caused by uneven alveolar emptying.



Multiple studies have confirmed the sloping shape correlates to bronchospasm and obstructive lung disease.

“The analysis of the capnogram’s shape is a quantitative method for evaluating the severity of bronchospasm.” –You, Expiratory capnography in asthma: evaluation of various shape indicies, European Respiratory Journal, Feb, 1994

Changing Asthma Values

Asthma values change with severity. With a mild asthma, the CO2 will drop (below 35) as the patient hyperventilates to compensate. As the asthma worsens, the C02 levels will rise to normal. When the asthma becomes severe, and the patient is tiring and has little air movement, the C02 numbers will rise to dangerous levels (above 60).

Successful treatment will lessen or eliminate the shark fin shape and return the ETCO2 to normal range (Patient below: capnogram on arrival, after start of 1st combi-vent, after two combivents).



Hypoxic Drive

Capnography will show the hypoxic drive in COPD "retainers." ETCO2 readings will steadily rise, alerting you to cut back on the oxygen before the patient becomes obtunded. Since it has been estimated that only 5% of COPDers have a hypoxic drive, monitoring capnography will also allow you to maintain sufficient oxygen levels in the majority of tachypneic COPDers without worry that they will hypoventilate.

CHF: Cardiac Asthma

It has been suggested that in wheezing patients with CHF (because the alveoli are still, for the most part, emptying equally), the wave form should be upright. This can help assist your clinical judgement when attempting to differentiate between obstructive airway wheezing such as COPD and the "cardiac asthma" of CHF.



(wave form of patient with cardiac asthma)

7. Ventilating Head Injured Patients

Capnography can help paramedics avoid hyperventilation in intubated head injured patients.

“Recent evidence suggests hyperventilation leads to ischemia almost immediately...current models of both ischemic and TBI suggest an immediate period during which the brain is especially vulnerable to secondary insults. This underscores the importance of avoiding hyperventilation in the prehospital environment.” --Capnography as a Guide to Ventilation in the Field, D.P. Davis, Gravenstein, Capnography: Clinical Perspectives, Cambridge Press, 2004

Hyperventilation decreases intracranial pressure by decreasing intracranial blood flow. The decreased cerebral blood flow may result in cerebral ischemia.

In a study of 291 intubated head injured patients, 144 had ETCO2 monitoring. Patients with ETCO2 monitoring had lower incidence of inadvertant severe hyperventilation (5.6%) than those without ETCO2 monitoring (13.4%). Patients in both groups with severe hyperventilation had significantly higher mortality (56%) than those without (30%). –Davis, The Use of Quantitative End-Tidal Capnometry to Avoid Inadvertant Severe Hyperventilation in Patients with Head Injury After Paramedic Rapid Sequence Intubation, Journal of Trauma, April 2004

“A target value of 35 mmHg is recommended...The propensity of prehospital personnel to use excessively high respiratory rates suggests that the number of breaths per minute should be decreased. On the other hand, the mounting evidence against tidal volumes in excessive of 10cc/kg especially in the absence of peep, would suggest the hypocapnia be addressed by lower volume ventilation.” – --Capnography as a Guide to Ventilation in the Field, D.P. Davis, Gravenstein, Capnography: Clinical Perspectives, Cambridge Press, 2004

8. Perfusion Warning Sign

End tidal CO2 monitoring can provide an early warning sign of shock. A patient with a sudden drop in cardiac output will show a drop in ETCO2 numbers that may be regardless of any change in breathing. This has implications for trauma patients, cardiac patients – any patient at risk for shock.

In the study cited below, 5 pigs had hemorrhagic shock induced by bleeding, 5 pigs had septic shock induced by infusion of e-coli, and 6 pigs had cardiogenic shock induced by repeated episodes of v-fib. The pigs' cardiac output was continuously measured as well as their PETCO2.

“Cardiac output and PetCO2 were highly related in diverse experimental models of circulatory shock in which cardiac output was reduced by >40 % of baseline values… measurement of PetC02 is a noninvasive alternative for continuous assessment of cardiac output during low flow circulatory shock states of diverse causes.” -Xiahua, End-tidal carbon dioxide as a noninvasive indicator of cardiac index during circulatory shock, Critical Care Medicine, 2000, Vol 28, No 7

“A patient with low cardiac output caused by cardiogenic shock or hypovolemia resulting from hemorrhage won’t carry as much CO2 per minute back to the lungs to be exhaled. This patient’s ETC02 will be reduced. It doesn’t necessarily mean the patient is hyperventilating or that their arterial CO2 level will be reduced. Reduced perfusion to the lungs alone causes this phenomenon. The patient’s lung function may be perfectly normal.” --Baruch Krauss, M.D, JEMS, November 2003

9. Other Issues:

DKA - Patients with DKA hyperventilate to lessen their acidosis. The hyperventilation causes their PAC02 to go down.

“End-tidal C02 is linearly related to HC03 and is significantly lower in children with DKA. If confirmed by larger trials, cut-points of 29 torr and 36 torr, in conjunction with clinical assessment, may help discriminate between patients with and without DKA, respectively.” –Fearon, End-tidal carbon dioxide predicts the presence and severity of acidosis in children with diabetes, Academic Emergency Medicine, December 2002

Pulmonary Embolus – Pulmonary embolus will cause an increase in the dead space in the lungs decreasing the alveoli available to offload carbon dioxide. The ETCO2 will go down.

Hyperthermia – Metabolism is on overdrive in fever, which may cause ETCO2 to rise. Observing this phenomena can be live-saving in patients with malignant hyperthermia, a rare side effect of RSI (Rapid Sequence Induction).

Trauma - A 2004 study of blunt trauma patients requiring RSI showed that only 5 percent of patients with ETCO2 below 26.25 mm Hg after 20 minutes survived to discharge. The median ETCO2 for survivors was 30.75. - Deakin CD, Sado DM, Coats TJ, Davies G. “Prehospital end-tidal carbon dioxide concentration and outcome in major trauma.” Journal of Trauma. 2004;57:65-68.

Field Disaster Triage - It has been suggested that capnography is an excellent triage tool to assess respiratory status in patients in mass casualty chemical incidents, such as those that might be caused by terrorism.

“Capnography…can serve as an effective, rapid assessment and triage tool for critically injured patients and victims of chemical exposure. It provides the ABCs in less than 15 seconds and identifies the common complications of chemical terrorism. EMS systems should consider adding capnography to their triage and patient assessment toolbox and emphasize its use during educational programs and MCI drills.”- Krauss, Heightman, 15 Second Triage Tool, JEMS, September 2006

Anxiety- ETCO2 is being used on an ambulatory basis to teach patients with anxiety disorders as well as asthmatics how to better control their breathing. Try (it may not always be possible) to get your anxious patient to focus on the monitor, telling them that as they slow their breathing, their ETCO2 number will rise, their respiratory rate number will fall and they will feel better.

Anaphylaxis- Some patients who suffer anaphylactic reactions to food they have ingested (nuts, seafood, etc.) may experience a second attack after initial treatment because the allergens remain in their stomach. Monitoring ETCO2 may provide early warning to a reoccurrence. The wave form may start to slope before wheezing is noticed.

Accurate Respiratory Rate - Studies have shown that many medical professionals do a poor job of recording a patient's respiratory rate. Capnography not only provides an accurate respiratory rate, it provides an accurate trend or respirations.

10. The Future

Capnography should be the prehospital standard of care for confirmation and continuous monitoring of intubation, as well as for monitoring ventilation in sedated patients. Additionally, it should see increasing use in the monitoring of unstable patients of many etiologies. As more research is done, the role of capnography in prehospital medicine will continue to grow and evolve.

***
10 Things Every Paramedic Should Know About Capnography
Peter Canning, EMT-P
December 29, 2007 (Version 6.3)

Disclaimer: The information in this paper is gathered from textbooks, research articles, web sites, lectures and my own experiences. Paramedics should consult their medical directors and protocols for approved uses.

Worn Down

At a doctor's office, there is a man in his 80's with a BP of 70, dizzy, not feeling well for two days. I take his pressure -- 68/34. He is pale and gray and does not look well. His capnography number is in the low to mid twenties, showing poor perfusion. I do a twelve lead and leads V2-V3 catch my attention.

The shape is often indicative of a posterior MI. I put a lead on his back and this is what it looks like.

I would have liked to have gotten a better tracing, but we are going on a priority. I toss him some aspirin and continue running fluid in through the IV. His lungs are clear. I call the hospital and say I have a possible posterior MI. I am hoping this will start the process of getting the cath lab ready for the man becuse that is what I believe he needs. I look at him again. He says nothing. He looks beat, like he knows he is really sick, and knows that he doesn't have the strength to do anything more than let whatever is happening either kill him or let him live. It is not in his hands. What is he thinking? Running through his life, I'd guess

I show my 12 lead to the nurse, and she quickly gets an old 12 lead off the hospital computer. A big change since the last one was done a month ago. She calls the doctor over and I give him my report.

When I left I thought he was jusrt about to be taken to the cath lab, but when I checked back later, the nurse told me they had sent him up to the Intensive Care Unit. She said he had nothing left to cath. He had had so many procedures in the past.

Cardiac calls are my favorite because they involve such a combnation of skills. Knowledge to be able to identify the MI, skills to put in two IVs en route, and experience to be able to move the call quickly from scene to the hospital, and then persuasion to be able to get the hospital to recognize what you have and get the cath lab ready. This guy just was too old and worn down to be helped.

He was still alive the next day, but the nurse said they expected him to die.

Capnography for Paramedics

I have created a new blog called:Capnography for Paramedics.

The purpose of the blog is to explore the issue of capnography in the prehospital setting. Unlike with 12-Lead ECGs, you can't just go out and buy a book on capnography. The information on capnography is out there, but not that accessible. I want to use this site to gather that information into one place, as well as to post my own experiences.

I first heard about capnography at the JEMS conference in Philadelphia a couple years ago. I took a one hour mini-class from a vendor. In one ear and out the other. I didn’t have capnography so it didn’t stick. Last year, we finally got capnography put on our Life Pack 12s. I learned how to put it on the ET tube, but the first couple codes I did, I completely forgot that I had it, then the next couple times I remembered about ten minutes into the code. Now, I keep an ET filter line in my airway kit, so it is starring at me when I unzip the kit.

The first code I used the End Tidal Monitoring on, I was alarmed that I didn’t get much of a wave form and that my capnography number was so low. (See Compressions). Later I did a call where the patient initailly looked so dead, I thought she was going to have rigor when I touched her, I popped the filter line on and was startled, after a few minutes of CPR, to suddenly see an End Tidal number of 35 (See A Blanket). A short time later we got pulses back and then later the patient began breathing on her own. I have learned that capnography can be a predictor of rescusitation chances.

Most of all a good capnography wave insures that the tube is in the trachea where its supposed to be and not in the esophagus which would produce a flat line, immediately on the capnography wave form and eventually on the heart monitor as well if the tube is not moved to the right place.

In April 2006 I took a really good class on capnography, taught by Gary Childs of the Mercy Hospital Education Center.

Part of the class covered capnography for the non-intubated patient, which was the main reason I took the class. Instead of an attachment on an ET tube, a nasal cannula-like monitoring device was put on the patient. We were taught that the shape of the wave form changed depending on the problem. Asthmatics and COPDers had a characteristic shark fin shape, which indicated resistance to expiration. (see post below.)

I am hooked on using capnography now, and every time I use it, it seems I learn something new.

The first posts in this blog will be arranged in order of key facts, information sources, and then my own wave forms and experiences. Because I am still a novice at it, I don't claim that my interpretations will be 100% accurate. If I am wrong or off-base or you can add something to my understanding, please feel free to comment. Also, any links to other capnography sites would be appreciated.

I hope the site will be helpful to those of you, like me, just learning about capnography.