Clinical trial NCT01821365: End Tidal Carbon Dioxide Monitoring for Evaluating Changes of PaCO2 After Noninvasive Mechanical Ventilation in COPD
Official title: End Tidal Carbon Dioxide Monitoring for Evaluating Changes of Arterial Carbon Dioxide After Noninvasive Mechanical Ventilation in Chronic Obstructive Pulmonary Disease
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: COPD
Keywords: COPD,PETCO2,PaCO2
Lead sponsor: The First Affiliated Hospital of Guangzhou Medical University
Sponsor class: OTHER
First posted: 2013-04-01
Enrollment: 40
Sex: ALL
Minimum age (years): 40
Maximum age (years): 85
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients with a COPD exacerbation who admitted to the respiratory department of First Affiliated Hospital of Guangzhou Medical University,Guangzhou,Guangdong,China

Brief summary: Sidestream end-tidal CO2 has been found to be closely correlated to PaCO2 especially when people have the stable hemodynamics and normal lung function. PETCO2 can basically reflect the level of PaCO2,but some investigators found that PETCO2 measurements did not reflect PaCO2 in COPD patients.There may be several reasons for this discrepancy. Due to airway obstruction and ventilation-perfusion mismatch, there is a delay in the maximum alveolar concentration of CO2 reaching the cannula, which may give lower PETCO2 values compared with PaCO2. To overcome this disadvantage, we tried to prolong their expiratory time (extend to 5-8s) in order to guarantee adequate time for alveolar CO2 reaching the cannula.our study mainly focus on two issues.First, to explore the optimal depth of tube placed when patients with COPD breathe spontaneously or receive noninvasive ventilation, and compare the differences of two condition at the same time. Secondly, to evaluate the agreement between the PaCO2 and sidestream PETCO2（5s）values in COPD patients receiving noninvasive ventilation when our extension tube locates in the optimal position, and investigate whether PETCO2（5s）can be used to monitor ventilation status dynamically.

Detailed description: Non-invasive positive pressure ventilation(NPPV) can significantly improve gas exchange and relieve respiratory muscle fatigue for COPD,and arterial blood gas is the gold standard to evaluate ventilation status,but the procedure is time consuming,invasive, painful and in some patients.

Sidestream end-tidal CO2 has been found to be closely correlated to PaCO2 especially when people have the stable hemodynamics and normal lung function. PETCO2 can basically reflect the level of PaCO2, but for patients with COPD, due to the presence of airway obstruction and emphysema formation, which cause ventilation-perfusion ratio(V/Q) , result to dead space-tidal volume ratio(VD/VT) and right-to-left shunting(Qs/Qt), the time of various lung units discharge of carbon dioxide is not synchronous. Some investigators found that PETCO2 measurements did not reflect PaCO2 in COPD patients. There may be several reasons for this discrepancy. Due to airway obstruction and ventilation-perfusion mismatch, there is a delay in the maximum alveolar concentration of CO2 reaching the cannula, which may give lower PETCO2 values compared with PaCO2. To overcome this disadvantage, we tried to prolong their expiratory time (extend to 5-8s) in order to guarantee adequate time for alveolar CO2 reaching the cannula.

our study mainly focus on two issues.First, to explore the optimal depth of tube placed when patients with COPD breathe spontaneously or receive noninvasive ventilation, and compare the differences of two condition at the same time. Secondly, to evaluate the agreement between the PaCO2 and sidestream PETCO2（5s）values in COPD patients receiving noninvasive ventilation when our extension tube locates in the optimal position, and investigate whether PETCO2（5s）can be used to monitor ventilation status dynamically.

Eligibility criteria: Inclusion Criteria:1.patients are enrolled in accordance with 2011 international treatment guidelines of COPD.

2.patients are in a clear state of mind and can incompliance with clinicians to extend breathing only using nose and closing mouth.

Exclusion Criteria:1.Hemodynamic instability. 2.Pulmonary embolism,Pneumothorax, pleural effusion, upper airway obstruction,Chest trauma, chest wall deformities, neuromuscular diseases, lung tumor.

3.combinating acute exacerbation of bronchial asthma in this hospitalization. 4.Nose and mouth trauma, deformity, or recent surgery.

Primary outcomes:
measure: the agreement and correlation between the partial pressure of end-tidal carbon dioxide(PETCO2)
timeFrame: one day
Secondary outcomes:
Other outcomes:
Locations:
city: Guangzhou
country: China
facility: The First Affiliated Hospital of Guangzhou Medical University
state: Guangdong
Study officials:
affiliation: The First Affiliated Hospital of Guangzhou Medical University
name: Rongchang Chen, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Wu CH, Chou HC, Hsieh WS, Chen WK, Huang PY, Tsao PN. Good estimation of arterial carbon dioxide by end-tidal carbon dioxide monitoring in the neonatal intensive care unit. Pediatr Pulmonol. 2003 Apr;35(4):292-5. doi: 10.1002/ppul.10260.
citation: Trevisanuto D, Giuliotto S, Cavallin F, Doglioni N, Toniazzo S, Zanardo V. End-tidal carbon dioxide monitoring in very low birth weight infants: correlation and agreement with arterial carbon dioxide. Pediatr Pulmonol. 2012 Apr;47(4):367-72. doi: 10.1002/ppul.21558. Epub 2011 Nov 18.
citation: Tai CC, Lu FL, Chen PC, Jeng SF, Chou HC, Chen CY, Tsao PN, Hsieh WS. Noninvasive capnometry for end-tidal carbon dioxide monitoring via nasal cannula in nonintubated neonates. Pediatr Neonatol. 2010 Dec;51(6):330-5. doi: 10.1016/S1875-9572(10)60064-2.
citation: McSwain SD, Hamel DS, Smith PB, Gentile MA, Srinivasan S, Meliones JN, Cheifetz IM. End-tidal and arterial carbon dioxide measurements correlate across all levels of physiologic dead space. Respir Care. 2010 Mar;55(3):288-93.
citation: Lopez E, Grabar S, Barbier A, Krauss B, Jarreau PH, Moriette G. Detection of carbon dioxide thresholds using low-flow sidestream capnography in ventilated preterm infants. Intensive Care Med. 2009 Nov;35(11):1942-9. doi: 10.1007/s00134-009-1647-5.
citation: Cinar O, Acar YA, Arziman I, Kilic E, Eyi YE, Ocal R. Can mainstream end-tidal carbon dioxide measurement accurately predict the arterial carbon dioxide level of patients with acute dyspnea in ED. Am J Emerg Med. 2012 Feb;30(2):358-61. doi: 10.1016/j.ajem.2010.12.014. Epub 2011 Jan 28.
citation: Howe TA, Jaalam K, Ahmad R, Sheng CK, Nik Ab Rahman NH. The use of end-tidal capnography to monitor non-intubated patients presenting with acute exacerbation of asthma in the emergency department. J Emerg Med. 2011 Dec;41(6):581-9. doi: 10.1016/j.jemermed.2008.10.017. Epub 2009 Mar 9.