Capnography: Is it helpful?. Has been called the 15 second triage tool The newest vital sign? Value lies in very simple application Advanced use requires in depth understanding of ventilation and perfusion. Key Uses of Capnography.
Purple – PetCO2% - < .5%
Tan – PetCO2% .5-2%
Yellow – PetCO2% - > 2%
Normal PetCO2 >4%
Bedside monitor mainstream capnogram
Hand held side stream capnogram
Phase indicating good
Case study - A 21 year old female is being transported for a CT scan. During transport, she extubates herself. The CRNA who is present immediately reintubates. While waiting for the CT to be started, he extubates himself again. The CRNA is not present. The nurse attempts to reintubate by waiting for inspiration and then sliding the tube back in. She hears breath sounds and she is trying to get the CRNA or physician to help. However, the question is, is the endotracheal tube in the correct location?
If PetCO2 increases, ventilation is threatened and airway protection is neededCapnography is more valuable than oximetry in assessing ventilation
A 44 yr old male admitted to MICU with unknown fever, SOB, hypoxemia. pH 7.34, PaCO2 38, PaO2 44, SpO2 .78. He is intubated, IMV 12/44. Extubates himself, is reintubated. Sedation is increased. RR decreases to 12. .What is the effect of sedation on ventilation?
Use in Critical Care
Reduced blood flow decreases alveolar CO2 - this decrease
is detected in the exhaled
breath by capnography
Weil et al 1999 - CCM
Levine, Wayne, Miller - NEJM - 1997
Asplin & White 1995 - Ann Emer Med
Domsky et al -1995 - CCM
Idris et al 1994 - Ann Emer Med
White & Asplin 1994 - Ann Emer Med
Ward et al 1993 - Ann Emer Med
Angelos et al 1992 - Resuscitation
Isserles & Breen 1991- A&A
Callaham & Barton 1990 - CCM
Gazmuri et al 1989 - CCM
Garnett et al 1987 - JAMA
Weil et al 1985 - CCM
Baraka AS, Aouad MT, Jalbout MI, Kaddoum RN, Khatib MF, Haroun-Bizri ST. End-tidal CO2 for prediction of cardiac output following weaning from cardiopulmonary bypass. J Extra Corpor Technol. 2004 Sep; 36(3) :255-7.
Deakin CD, Sado DM, Coats TJ, Davies G. Prehospital end-tidal carbon dioxide concentration and outcome in major trauma. J Trauma 2004 Jul;57(1):65-8.
Grmec S, Krizmaric M, Mally S, Kozelj A, Spindler M, Lesnik B. Utstein style analysis of out-of-hospital cardiac arrest--bystander CPR and end expired carbon dioxide. Resuscitation 2007; Mar;72(3):404-14.
Gazmuri RJ, Kube E. Capnography during cardiac resuscitation: a clue on mechanisms and a guide to interventions. Crit Care. 2003;7(6):411-412. Epub 2003 Oct 06.
Kline JA, Arunachlam M. Preliminary study of the capnogram waveform area to screen for pulmonary embolism. Ann Emerg Med. 1998 Sep;32(3 Pt 1):289-96.
Kunkov S, Pinedo V, Silver EJ, Crain EF. Predicting the need for hospitalization in acute childhood asthma using end-tidal capnography. Pediatr Emerg Care. 2005 Sep;21(9):574-7.
Mallick A, Venkatanath D, Elliot SC, Hollins T, Nanda Kumar CG. A prospective randomised controlled trial of capnography vs. bronchoscopy for Blue Rhino percutaneous tracheostomy. Anaesthesia. 2003 Sep;58(9):864-8.
Pernat A, Weil MH, Sun S, Tang W. Stroke volumes and end-tidal carbon dioxide generated by precordial compression during ventricular fibrillation. Crit Care Med. 2003 Jun;31(6):1819-23
Sanchez O, Wermert D, Faisy C, Revel MP, Diehl JL, Sors H, Meyer G. Clinical probability and alveolar dead space measurement for suspected pulmonary embolism in patients with an abnormal D-dimer test result. J Thromb Haemost. 2006 Jul;4(7):1517-22.
Sehra R, Underwood K, Checchia P. End tidal CO2 is a quantitative measure of cardiac arrest. Pacing Clin Electrophysiol 2003 Jan;26(1 Pt 2):515-7CPR, Blood Flow and Outcomes
Case #1 - A 66 yr old female is brought into the ER, CPR is in progress. She was found “down” in her house by her husband. Paramedics have been doing CPR for > 20 minutes. Her capnography wave shows a value of 6 mm Hg. How would you assess the adequacy of the resuscitation effort?
showing a value of
A 73 yr old male following a CABG and valve replacement complains of acute shortness of breath at 0630. He has the following information present:0600 0630 BP 112/68 122/76P – 92 110IMV 10/14 IMV 10/22SpO2 .97 SpO2 .95PaCO2 – 32 PaCO2 - 29PetCO2 - 28 PetCO2 - 7 (see waveform below)Is this possibly an anxious reaction due to postoperative fear or has some physiologic problem, like a PE occurred?
1) Which of the following are indicators of sudden loss of blood flow
2) Which of the following indicate an increased deadspace
3) Which of the following are consistent with a sudden loss of cardiac output?
4) If the PaCO2 is 40 and the PetCO2 is 35, what does that reveal about deadspace?
5) If the PetCO2 suddenly falls from 35 to 20 without a change in Ve, what has likely happened?
6) If a capnogram suddenly goes flat on a patient on mechanical ventilation, what has likely happened?