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End-tidal carbon dioxide monitoring using a naso-buccal sensor is not appropriate to monitor capnia during non-invasive ventilation.

Piquilloud L, Thevoz D, Jolliet P, Revelly JP - Ann Intensive Care (2015)

Bottom Line: EtCO2 and expiratory CO2 values during active and passive expiratory maneuvers were measured using a dedicated naso-buccal sensor and compared to concomitant PaCO2 values.Adding active and passive expiration maneuvers did not improve PaCO2 prediction.Active and passive expiration maneuvers did not improve PaCO2 prediction.

View Article: PubMed Central - PubMed

Affiliation: Adult Intensive Care and Burn Unit, University Hospital of Lausanne, Lausanne, Switzerland.

ABSTRACT

Background: In acute respiratory failure, arterial blood gas analysis (ABG) is used to diagnose hypercapnia. Once non-invasive ventilation (NIV) is initiated, ABG should at least be repeated within 1 h to assess PaCO2 response to treatment in order to help detect NIV failure. The main aim of this study was to assess whether measuring end-tidal CO2 (EtCO2) with a dedicated naso-buccal sensor during NIV could predict PaCO2 variation and/or PaCO2 absolute values. The additional aim was to assess whether active or passive prolonged expiratory maneuvers could improve the agreement between expiratory CO2 and PaCO2.

Methods: This is a prospective study in adult patients suffering from acute hypercapnic respiratory failure (PaCO2 ≥ 45 mmHg) treated with NIV. EtCO2 and expiratory CO2 values during active and passive expiratory maneuvers were measured using a dedicated naso-buccal sensor and compared to concomitant PaCO2 values. The agreement between two consecutive values of EtCO2 (delta EtCO2) and two consecutive values of PaCO2 (delta PaCO2) and between PaCO2 and concomitant expiratory CO2 values was assessed using the Bland and Altman method adjusted for the effects of repeated measurements.

Results: Fifty-four datasets from a population of 11 patients (8 COPD and 3 non-COPD patients), were included in the analysis. PaCO2 values ranged from 39 to 80 mmHg, and EtCO2 from 12 to 68 mmHg. In the observed agreement between delta EtCO2 and deltaPaCO2, bias was -0.3 mmHg, and limits of agreement were -17.8 and 17.2 mmHg. In agreement between PaCO2 and EtCO2, bias was 14.7 mmHg, and limits of agreement were -6.6 and 36.1 mmHg. Adding active and passive expiration maneuvers did not improve PaCO2 prediction.

Conclusions: During NIV delivered for acute hypercapnic respiratory failure, measuring EtCO2 using a dedicating naso-buccal sensor was inaccurate to predict both PaCO2 and PaCO2 variations over time. Active and passive expiration maneuvers did not improve PaCO2 prediction.

Trial registration: ClinicalTrials.gov: NCT01489150.

No MeSH data available.


Related in: MedlinePlus

Evolution over time of PaCO2-EtCO2gradient for all the patients. This figure shows the evolution over time of PaCO2-EtCO2 gradient for all the patients. PaCO2, CO2 partial pressure in arterial blood; EtCO2, end-tidal CO2. Patient numbers 1, 3, 4, 5, 7, 9, 10, and 11 are COPD patients.
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Fig5: Evolution over time of PaCO2-EtCO2gradient for all the patients. This figure shows the evolution over time of PaCO2-EtCO2 gradient for all the patients. PaCO2, CO2 partial pressure in arterial blood; EtCO2, end-tidal CO2. Patient numbers 1, 3, 4, 5, 7, 9, 10, and 11 are COPD patients.

Mentions: When assessing agreement between PaCO2 and EtCO2 absolute values, bias was 14.7 mmHg and the limits of agreement were −6.6 and 36.1 mmHg (Figure 4). The Bland and Altman graphic representation is displayed in Figure 4 both for COPD patients and non-COPD patients. Pa-E′CO2 was 12.4 [8.6-20.2] mmHg in median but very high values were documented in some patients (maximal value of 42.7 mmHg) and non-physiologic slightly negative values were observed in one patient (Figure 5). The number of clinically unacceptable values for Pa-E′CO2 was 35/54 (65%).Figure 4


End-tidal carbon dioxide monitoring using a naso-buccal sensor is not appropriate to monitor capnia during non-invasive ventilation.

Piquilloud L, Thevoz D, Jolliet P, Revelly JP - Ann Intensive Care (2015)

Evolution over time of PaCO2-EtCO2gradient for all the patients. This figure shows the evolution over time of PaCO2-EtCO2 gradient for all the patients. PaCO2, CO2 partial pressure in arterial blood; EtCO2, end-tidal CO2. Patient numbers 1, 3, 4, 5, 7, 9, 10, and 11 are COPD patients.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385013&req=5

Fig5: Evolution over time of PaCO2-EtCO2gradient for all the patients. This figure shows the evolution over time of PaCO2-EtCO2 gradient for all the patients. PaCO2, CO2 partial pressure in arterial blood; EtCO2, end-tidal CO2. Patient numbers 1, 3, 4, 5, 7, 9, 10, and 11 are COPD patients.
Mentions: When assessing agreement between PaCO2 and EtCO2 absolute values, bias was 14.7 mmHg and the limits of agreement were −6.6 and 36.1 mmHg (Figure 4). The Bland and Altman graphic representation is displayed in Figure 4 both for COPD patients and non-COPD patients. Pa-E′CO2 was 12.4 [8.6-20.2] mmHg in median but very high values were documented in some patients (maximal value of 42.7 mmHg) and non-physiologic slightly negative values were observed in one patient (Figure 5). The number of clinically unacceptable values for Pa-E′CO2 was 35/54 (65%).Figure 4

Bottom Line: EtCO2 and expiratory CO2 values during active and passive expiratory maneuvers were measured using a dedicated naso-buccal sensor and compared to concomitant PaCO2 values.Adding active and passive expiration maneuvers did not improve PaCO2 prediction.Active and passive expiration maneuvers did not improve PaCO2 prediction.

View Article: PubMed Central - PubMed

Affiliation: Adult Intensive Care and Burn Unit, University Hospital of Lausanne, Lausanne, Switzerland.

ABSTRACT

Background: In acute respiratory failure, arterial blood gas analysis (ABG) is used to diagnose hypercapnia. Once non-invasive ventilation (NIV) is initiated, ABG should at least be repeated within 1 h to assess PaCO2 response to treatment in order to help detect NIV failure. The main aim of this study was to assess whether measuring end-tidal CO2 (EtCO2) with a dedicated naso-buccal sensor during NIV could predict PaCO2 variation and/or PaCO2 absolute values. The additional aim was to assess whether active or passive prolonged expiratory maneuvers could improve the agreement between expiratory CO2 and PaCO2.

Methods: This is a prospective study in adult patients suffering from acute hypercapnic respiratory failure (PaCO2 ≥ 45 mmHg) treated with NIV. EtCO2 and expiratory CO2 values during active and passive expiratory maneuvers were measured using a dedicated naso-buccal sensor and compared to concomitant PaCO2 values. The agreement between two consecutive values of EtCO2 (delta EtCO2) and two consecutive values of PaCO2 (delta PaCO2) and between PaCO2 and concomitant expiratory CO2 values was assessed using the Bland and Altman method adjusted for the effects of repeated measurements.

Results: Fifty-four datasets from a population of 11 patients (8 COPD and 3 non-COPD patients), were included in the analysis. PaCO2 values ranged from 39 to 80 mmHg, and EtCO2 from 12 to 68 mmHg. In the observed agreement between delta EtCO2 and deltaPaCO2, bias was -0.3 mmHg, and limits of agreement were -17.8 and 17.2 mmHg. In agreement between PaCO2 and EtCO2, bias was 14.7 mmHg, and limits of agreement were -6.6 and 36.1 mmHg. Adding active and passive expiration maneuvers did not improve PaCO2 prediction.

Conclusions: During NIV delivered for acute hypercapnic respiratory failure, measuring EtCO2 using a dedicating naso-buccal sensor was inaccurate to predict both PaCO2 and PaCO2 variations over time. Active and passive expiration maneuvers did not improve PaCO2 prediction.

Trial registration: ClinicalTrials.gov: NCT01489150.

No MeSH data available.


Related in: MedlinePlus