Capnography

[tomcbad]

Does anybody know what the wave form in a chf patient looks like? Or know any web sites that have that info.

[AZCEP]

Try capnography.com

[Ridryder 911]

That is a great site.. as well as many others. I highly suggest you search for any articles written by Dr. Krauss, he is a emergency physician that is pro-EMS capnography... check JEMS and this months JEMS Capnography for triage written by him as well. CHF will produce normal wave forms however you may have a different set of Co[sub:86b0bedbc5]2[/sub:86b0bedbc5] level. Remember, CHF is not obstructive but congestive at the capillary level...

R/r 911

[medic001918]

That is a great site.. as well as many others. I highly suggest you search for any articles written by Dr. Krauss, he is a emergency physician that is pro-EMS capnography... check JEMS and this months JEMS Capnography for triage written by him as well. CHF will produce normal wave forms however you may have a different set of Co[sub:8c5716a07e]2[/sub:8c5716a07e] level. Remember, CHF is not obstructive but congestive at the capillary level...

R/r 911

+1, the waveform doesn't look obstructed at all, so there isn't the "shark wave" look like you see with asthma of COPD. As the patient tires, they begin to hypoventilate or have insufficient respiration causing an increase in ETCO2. As the number rises, the likihood of having to assist w/ventilations increases significantly. As the patient has their O2/CO2 exchange impeded by edema within the lungs, the number will drop indicating a lack of or poor cellular exchange occuring.

Shane

NREMT-P

[Spock]

I agree with Rid once again--there is no distinctive waveform for CHF but hypoventilation will give you higher numbers. Great minds think alike.

Not all patients with asthma or COPD will exhibit the classic shark fin wave form. I've had many patients wheezing badly with high peak pressures on the vent and they had a normal wave form while others have had a classic shark fin with no wheezing and normal pressures. Capnography is a great tool and I still feel if you don't have it you shouldn't be intubating but we must remember that it is just one of the many tools (monitors) we use and we must always assess our patient. We treat the patient and not the monitor.

I looked briefly at that website and liked what I saw. I'll have to look at it closer. Rid--what other sites are available?

Live long and prosper.

Spock

[medic001918]

Here is a blog about capnography written by one of the paramedics that I work with. It contains many great links to other studies as well as a fair amount of good information.

Shane

NREMT-P

*EDIT* Would have been nice if I included the link... http://www.emscapnography.blogspot.com/

[Ridryder 911]

Here are some excellent sites for EMS and capnography.. my mentor on capnography Dr. Krauss

1'st is ppt presentations ...

http://www.tdh.state.tx.us/hcqs/ems/Krauss...Capnography.pdf

http://www2.us.elsevierhealth.com/inst/ser...;id=ajem0301028

http://emscapnography.blogspot.com/2006/05...hould-know.html

http://www.oridion.com/english/capnography...vironments/ems/

http://www.enw.org/ETCO2inCPR.htm

I thought this was interesting as well.

The effectiveness of out-of-hospital use of continuous end-tidal carbon dioxide monitoring on the rate of unrecognized misplaced intubation within a regional emergency medical services system.

Silvestri S, Ralls GA, Krauss B, Thundiyil J, Rothrock SG, Senn A, Carter E, Falk J.

Department of Emergency Medicine, Orlando Regional Medical Center, Orlando, FL, USA. ems.medicaldirector@ocfl.net

STUDY OBJECTIVE: We evaluate the association between out-of-hospital use of continuous end-tidal carbon dioxide (ETCO2) monitoring and unrecognized misplaced intubations within a regional emergency medical services (EMS) system. METHODS: This was a prospective, observational study, conducted during a 10-month period, on all patients arriving at a regional Level I trauma center emergency department who underwent out-of-hospital endotracheal intubation. The regional EMS system that serves the trauma service area is composed of multiple countywide systems containing numerous EMS agencies. Some of the EMS agencies had independently implemented continuous ETCO2 monitoring before the start of the study. The main outcome measure was the unrecognized misplaced intubation rate with and without use of continuous ETCO2 monitoring. RESULTS: Two hundred forty-eight patients received out-of-hospital airway management, of whom 153 received intubation. Of the 153 patients, 93 (61%) had continuous ETCO2 monitoring, and 60 (39%) did not. Forty-nine (32%) were medical patients, 104 (68%) were trauma patients, and 51 (33%) were in cardiac arrest. The overall incidence of unrecognized misplaced intubations was 9%. The rate of unrecognized misplaced intubations in the group for whom continuous ETCO2 monitoring was used was zero, and the rate in the group for whom continuous ETCO2 monitoring was not used was 23.3% (95% confidence interval 13.4% to 36.0%). CONCLUSION: No unrecognized misplaced intubations were found in patients for whom paramedics used continuous ETCO2 monitoring. Failure to use continuous ETCO2 monitoring was associated with a 23% unrecognized misplaced intubation rate

and another point

WASHINGTON, DC—Emergency medicine researchers have found that paramedics are more likely to recognize a patient’s breathing tube was placed incorrectly if they monitor end-tidal (exhaled) CO2 continuously. However, the study’s authors note that not all out-of-hospital personnel use this method of treatment. The study will be published online today as an early release by Annals of Emergency Medicine and will appear in the journal’s May 2005 print edition (The Effectiveness of Out-of-Hospital Use of Continuous End-tidal Carbon Dioxide Monitoring on the Rate of Unrecognized Misplaced Intubation within a Regional Emergency Medical Services System).

Routinely, paramedics and other emergency medical personnel perform endotracheal intubation, an emergency medical procedure, which requires placing a flexible, clear, plastic breathing tube down into the trachea to help air pass freely to and from the lungs. When a breathing tube is unwittingly misplaced in a patient’s esophagus rather than the trachea, or becomes dislodged during patient movement and is not recognized and corrected, it can cause life-threatening complications by sending oxygen to the stomach instead of the lungs. These complications can lead not only to insufficient ventilation, but also to stomach rupture, airway trauma, irreversible damage to the heart or brain, or even death.

Of the 153 patients who were intubated before arriving at a regional level I trauma center emergency department, 93 (61 percent) had received continuous end-tidal CO2 (ETCO2) monitoring and 60 (39 percent) did not. The rate of unrecognized misplaced intubations in the group who received ETCO2 monitoring was zero, and 23.3 percent in the group who did not receive it.

The study, which took place over a 10-month period, involved about 45 EMS agencies from 10 different counties in Florida. Researchers were able to identify that about half (21) of the EMS agencies did not use continuous ETCO2 monitoring on intubated patients.

End-tidal CO2 detectors are listed among a standardized list of equipment for ambulances jointly published by the American College of Emergency Physicians and the American College of Surgeons. However, researchers say not all ambulances meet these standards.

"There have been many studies demonstrating that sole utilization of clinical confirmation of tube location is unreliable, but research is now showing us that with the right equipment paramedics can monitor tube location much more safely and effectively," said Salvatore Silvestri, MD, Medical Director of the Orange County EMS System in Orange County, Florida. "The evidence presented in our study may persuade more EMS systems to consider equipping their ambulances with continuous end-tidal CO2 detection capabilities."

I agree it is ONLY a tool and does not replace assessment by any means, but should be used as an adjunct . My friend and cardiac mentor Bob Page describes :"End Tidal CO2 reading without a waveform is like a heart rate without an ECG recording.” ..

R/r 911

[Spock]

I really liked the study out of Orlando and I frequently cite it.

Live long and prosper.

Spock

[Ace844]

(Acad Emerg Med Volume 13 @ Number 5 500-504,

published online before print March 28, 2006, doi: 10.1197/j.aem.2005.12.017

© 2006 Society for Academic Emergency Medicine CLINICAL INVESTIGATION

Does End-tidal Carbon Dioxide Monitoring Detect Respiratory Events Prior to Current Sedation Monitoring Practices?

John H. Burton, MD, John D. Harrah, MD, Carl A. Germann, MD and Douglas C. Dillon, MD

From the Department of Emergency Medicine, Maine Medical Center (JHB, JDH, CAG, DCD), Portland, ME; and the Department of Emergency Medicine, Albany Medical Center (JHB), Albany, NY.

Address for correspondence and reprints: John H. Burton, MD, Emergency Department, MC-139, 47 New Scotland Avenue, Albany, NY 12208. Fax: 518-262-3236; e-mail: burtonj@mail.amc.edu.)

Objectives: The value of ventilation monitoring with end-tidal carbon dioxide (ETCO2) to anticipate acute respiratory events during emergency department (ED) procedural sedation and analgesia (PSA) is unclear. The authors sought to determine if ETCO2 monitoring would reveal findings indicating an acute respiratory event earlier than indicated by current monitoring practices.

Methods: The study included a prospective convenience sample of ED patients undergoing PSA. Clinicians performed ED PSA procedures with generally accepted patient monitoring, including oxygen saturation (SpO2), and clinical ventilation assessment. A study investigator recorded ETCO2 levels and respiratory events during each PSA procedure, with clinical providers blinded to ETCO2 levels. Acute respiratory events were defined as SpO2 92%, increases in the amount of supplemental oxygen provided, use of bag-valve mask or oral/nasal airway for ventilatory assistance, repositioning or airway alignment maneuvers, and use of physical or verbal means to stimulate patients with depressed ventilation or apnea, and reversal agent administration.

Results: Enrollment was stopped after independent review of 20 acute respiratory events in 60 patient sedation encounters (33%). Abnormal ETCO2 findings were documented in 36 patients (60%). Seventeen patients (85%) with acute respiratory events demonstrated ETCO2 findings indicative of hypoventilation or apnea during PSA. Abnormal ETCO2 findings were documented before changes in SpO2 or clinically observed hypoventilation in 14 patients (70%) with acute respiratory events.

Conclusions: Abnormal ETCO2 findings were observed with many acute respiratory events. A majority of patients with acute respiratory events had ETCO2 abnormalities that occurred before oxygen desaturation or observed hypoventilation.

[Ace844]

(Emergency Medicine Journal 2006;23:578-579; doi:10.1136/emj.2006.035907

© 2006 by BMJ Publishing Group Ltd @ and British Association for Accident and Emergency Medicine

REFLECTIONS ON PREHOSPITAL CARE

EtCO2: the key to effective prehospital ventilation

R Owen1 and N Castle2

1 Surrey Ambulance Service NHS Trust, The Horseshoe, Bolters Lane, Banstead, SM7 2AS, UK

2 Durban Institute of Technology, Durban, South Africa

Correspondence to:

Corresponding author: R Owen

Surrey Ambulance Service NHS Trust, The Horseshoe, Bolters Lane, Banstead, SM7 2AS, UK; robert.owen@surrey-ambulance.nhs.uk

Accepted for publication

10 March 2006)

DESCRIPTION

An advanced life support (ALS) unit staffed by two paramedics and two students was dispatched to a road traffic accident in South Africa. On arrival the team noted an adult male who had fallen from a minibus travelling at speed. The patient was noted to be in extremis:

A. Airway was partially obstructed by blood/vomit, although the patient was lying in a lateral position

B. Respiration was shallow at 6 breaths min–1 and oxygen saturation via pulse oximetry was 100% on high-flow oxygen

C. Heart rate was 100 bpm and blood pressure 160/100 mm Hg

D. Eyes – 1; verbal – 1; motor – 3

E. Isolated head injury with no other obvious injuries

Treatment priorities where dictated by the need to secure/protect the airway, concerns over hypoventilation,1 and prolonged hospital transfer time. The decision was made to attempt to reduce secondary hypoxic brain injury through endotracheal intubation.2 Due to the presence of trismus, midazolam (5 mg IV) was selected to facilitate intubating conditions. Sedation assisted intubation is common practice in South Africa.

Pre-oxygenation was continued with the patient on his side, a second IV line was secured, and the medication and equipment were prepared. Following a thorough but quick team briefing, the patient was log rolled onto his back and intubated. It was decided to hand ventilate the patient until he was in the ambulance where the mechanical transport ventilator would be used.

THE ISSUE

The authors were aware of the tendency of health care professionals to hyperventilate intubated patients3,4 and therefore one paramedic supervised the ventilation of the patient by a student who was specifically instructed to ensure that the ventilation rate did not exceed 10 min–1. Our aim was to maintain optimum EtCO2, but despite every effort to control hand ventilation, marked variations in the patient’s EtCO2 were noted (range 7–44 mm Hg). These were significantly outside the target range of 32–38 mm Hg that would indicate normocapnia.5

Once ventilation was transferred to the mechanical ventilator, which was set at 10 min–1 with a tidal volume of approximately 6 ml/kg,5 a steady EtCO2 was maintained. On reflection, the team challenged the decision to delay mechanical ventilation until the patient was in the ambulance.

REFLECTION

The purpose of reflection is to critically review an action and challenge clinical decisions, thereby confirming or changing practice.6 The authors were aware of the deficiencies of hand ventilation compared to the use of mechanical ventilation7 but decided to delay use of the ventilator until the patient was in the ambulance to facilitate patient movement. This decision was based on the belief that careful hand ventilation with EtCO2 monitoring would allow an acceptable EtCO2 range to be maintained.

Without reflective practice there is a risk that clinicians will continue to act on "auto-pilot" as was the case in this instance.8 It is common practice to hand ventilate a patient until a mechanical ventilator has been configured or during short transfers, and prior to this case the authors had not challenged this mode of ventilation as it had become an accepted standard of care.

It is evident from the literature that hyperventilation occurs during the prehospital management of intubated patients3,4 and that this has a negative impact on outcomes.4 Our reflection highlighted the inability of hand ventilation to achieve effective ventilation as there is no control of minute volume due to breath-to-breath variability.9 However, variations of up to 20% from the pre-set values of the commonly used transport ventilators have been reported,9 but this difference will remain constant and therefore can be detected and compensated for.

A key aspect of prehospital ventilation as demonstrated during our reflection is patient specific tidal volumes, thereby challenging the previous approach of 10 ml/kg at 10 min–1.10 The choice of 6 ml/kg at 10 min–1 facilitated effective ventilation as demonstrated by Helm et al.11

The management of this patient inadvertently provided an opportunity to make a qualitative and quantitative comparison of two ventilation strategies. This case highlighted the role of EtCO2 monitoring in the context of prehospital ventilation and the importance of education in ventilation strategies and not just the psychomotor skill of intubation.

Perhaps most importantly for the authors, it provided stark evidence that patient care can be improved by challenging commonly held beliefs. The reflection that followed this case has resulted in a number of changes to the standard operating procedures of the paramedic unit involved, resulting in the earlier use of mechanical ventilation and mandatory use of EtCO2 in all intubated patients. This is particularly important, as this ALS unit has been tasked with evaluating the introduction of prehospital rapid sequence intubation within South Africa.

FOOTNOTES

Competing interests: none declared

REFERENCES

Dunham MC, Barraco RD, Clark DE, et al. Guidelines for emergency tracheal intubation immediately after traumatic injury. J Trauma 2003;55:162–79.[Medline]

Winchell RJ, Hoyt DB. Endotracheal intubation in the field improves survival in patients with severe head injury. Arch Surg 1997;132:592–7.[Abstract]

Aufderheide TP, Sigurdsson G, Pirrallo RG, et al. Hyperventilation-induced hypotension during cardiopulmonary resuscitation. Circulation 2004;109:1960–5.[Abstract/Free Full Text]

Davis DP, Dunford JV, Poste JC, et al. The impact of hypoxia and hyperventilation on outcome after paramedic rapid sequence intubation of severely head-injured patients. J Trauma 2004;57:1–10.[Medline]

Rayner-Klein J. Commentary on: pre-hospital emergency anaesthesia. J R Army Med Corps 2004;150:72–3.

Johns C. Becoming a reflective practitioner. A reflective and holistic approach to clinical nursing, practise development and clinical supervision. London: Blackwell Science, 2000.

Helm M, Hauke J, Lampl L. A prospective study of the quality of pre-hospital emergency ventilation in patients with severe head injury. B J Anaesth 2002;88:345–9.[Abstract/Free Full Text]

Cox H, Hickson P, Taylor B. Exploring reflection: knowing and constructing practice. In: Gray G, Pratt R, eds. Towards a discipline of nursing. Edinburgh: Churchill Livingstone, 1994:378.

Helm M, Fischer S. The role of capnography in pre-hospital ventilation for trauma patients. Int J Intensive Care 2005;12 (3) :124–30.

Walls RM, Luten RC, Murphy MF, et al, eds. Manual of emergency airway management. Philadelphia: Lippincott, Williams and Wilkins, 2000.

Helm M, Schuster R, Hauke J, et al. Tight control of prehospital ventilation by capnography in major trauma victims. B J Anaesth 2003;90:327–32.[Abstract/Free Full Text]

The role of EtCO2 monitoring in the prehospital setting 7 July 2006

Michael R Duffy,

Specialist Registrar Intensive Care

Royal Cornwall Hospital

Send letter to journal:

Re: The role of EtCO2 monitoring in the prehospital setting

Email Michael R Duffy

Dear Editor,

A recent article in this journal reflected on the key role of end- tidal carbon dioxide (EtCO2) monitoring for effective prehospital ventilation [1]. However, during the management of critically ill patients the most important role of EtCO2 monitoring is to confirm correct placement of the tracheal tube during tracheal intubation and then subsequently to function as an airway disconnection alarm. In effect, the main role of EtCO2 monitoring is to ensure that there is some oxygenation of the patient rather than ventilation per se.

The relationship between EtCO2 and arterial PCO2 (PaCO2) is not reliable[2,3]. In the prehospital setting Belpomme et al. (2005) found a wide variation in the gradient between PaCO2 and EtCO2 with individual patients, and over time, the relationship does not remain constant [3]. The assumption that EtCO2 acts as a surrogate for trends in PaCO2 is misleading. This important monitoring device may therefore not be the key to ensuring effective prehospital ventilation.

References

1. Owen R, Castle N. EtCO2: the key to effective prehospital ventilation. Emergency Medical Journal 2006; 27(3): 578-579.

2. Seguin P, Bleicher JP, Branger B, Guillou YM, Feuillu A, Malledant Y. The measurement of end-tidal carbon dioxide (PETCO2) is not a significant parameter to monitor in patients with severe traumatic brain injury. Canadian Journal of Anaesthesia 2001; 48(4): 396-400.

3. Belpomme V, Ricard-Hibon A, Devoir C, Dileseigres S, Devaud ML, Chollet C, Marty J. Correlation of arterial PCO2 and PETCO2 in prehospital controlled ventilation. American Journal of Emergency Medicine 2005; 23(7): 852-9.