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Application of CO 2 waveform in the alveolar recruitment maneuvers of hypoxemic patients during one-lung ventilation

View Article: PubMed Central - PubMed

ABSTRACT

Deterioration of gas exchange during one-lung ventilation (OLV) is caused by both total collapse of the nondependent lung and partial collapse of the dependent lung. Alveolar recruitment maneuver improves lung function during general anesthesia. The objective of this study was to investigate whether there is an indirect relationship between the changes of CO2 expirogram and the selective lung recruitment. To further improve the oxygenation and gas exchange, we compare adjust setting of ventilated parameters based on CO2 expirogram and a preset setting of ventilated parameters during OLV in patients undergoing right-side thoracic surgery.

Thirty patients met the requirements criteria that were studied at 3 time points: during two-lung ventilation (TLV), during OLV with preset ventilation parameters (OLV-PP), and during OLV with adjustable ventilation parameters (OLV-AP) that are in accordance with CO2 expirogram. Adjustable ventilation parameters such as tidal volume (VT), respiratory rate (RR), positive end-expiratory pressure (PEEP), and the ratio of inspiratory to expiratory were adjusted by utilizing the phase III slopes of CO2 expirogram, which together with the relationship between the changes of CO2 expirogram and the selective lung recruitment.

During OLV, the phase III slopes of CO2 expirogram in patients with pulse oxymetry (SpO2) decreased less than 93% after the OLV-PP, and were absolutely different from that during TLV. After OLV-AP, the phase III slopes of CO2 expirogram and SpO2 were similar to those during TLV. During OLV, however, parameters of ventilation setting in both OLV-PP and OLV-AP are obviously different.

This study indicates that alveolar recruitment by utilizing CO2 expirogram probably improves SpO2 level during one-lung ventilation.

No MeSH data available.


CO2 waveform with superimposed waveform parameters. Phase I, points B to C (ascending phase); Phase II, points C to D (alveolar plateau); Phase III, points D to E (descending phase); ALS, alveolar slope; AS, ascending slope; DS, descending slope.
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Figure 1: CO2 waveform with superimposed waveform parameters. Phase I, points B to C (ascending phase); Phase II, points C to D (alveolar plateau); Phase III, points D to E (descending phase); ALS, alveolar slope; AS, ascending slope; DS, descending slope.

Mentions: Standard monitoring including electrocardiogram, heart rate (HR), invasive arterial blood pressure, and SpO2 was collected by the Datex Ohmeda S/5 monitor during the entire study period. Prior to use, the PETCO2 was measured using an infrared analyzer with a side stream sampler attached at the elbow between the endotracheal tube and the anesthesia circuit and the device was calibrated according to the manufacturer's recommendations. The CO2 waveform was obtained by monitoring PETCO2 on a monitor following tracheal cannulation during the two lung ventilation and as a basic CO2 waveform. However, CO2 waveforms are characterized by a triphasic shape that has been described in normal (see Fig. 1),[8] therefore it is referenced as a basic CO2 waveform during TLV.


Application of CO 2 waveform in the alveolar recruitment maneuvers of hypoxemic patients during one-lung ventilation
CO2 waveform with superimposed waveform parameters. Phase I, points B to C (ascending phase); Phase II, points C to D (alveolar plateau); Phase III, points D to E (descending phase); ALS, alveolar slope; AS, ascending slope; DS, descending slope.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4998475&req=5

Figure 1: CO2 waveform with superimposed waveform parameters. Phase I, points B to C (ascending phase); Phase II, points C to D (alveolar plateau); Phase III, points D to E (descending phase); ALS, alveolar slope; AS, ascending slope; DS, descending slope.
Mentions: Standard monitoring including electrocardiogram, heart rate (HR), invasive arterial blood pressure, and SpO2 was collected by the Datex Ohmeda S/5 monitor during the entire study period. Prior to use, the PETCO2 was measured using an infrared analyzer with a side stream sampler attached at the elbow between the endotracheal tube and the anesthesia circuit and the device was calibrated according to the manufacturer's recommendations. The CO2 waveform was obtained by monitoring PETCO2 on a monitor following tracheal cannulation during the two lung ventilation and as a basic CO2 waveform. However, CO2 waveforms are characterized by a triphasic shape that has been described in normal (see Fig. 1),[8] therefore it is referenced as a basic CO2 waveform during TLV.

View Article: PubMed Central - PubMed

ABSTRACT

Deterioration of gas exchange during one-lung ventilation (OLV) is caused by both total collapse of the nondependent lung and partial collapse of the dependent lung. Alveolar recruitment maneuver improves lung function during general anesthesia. The objective of this study was to investigate whether there is an indirect relationship between the changes of CO2 expirogram and the selective lung recruitment. To further improve the oxygenation and gas exchange, we compare adjust setting of ventilated parameters based on CO2 expirogram and a preset setting of ventilated parameters during OLV in patients undergoing right-side thoracic surgery.

Thirty patients met the requirements criteria that were studied at 3 time points: during two-lung ventilation (TLV), during OLV with preset ventilation parameters (OLV-PP), and during OLV with adjustable ventilation parameters (OLV-AP) that are in accordance with CO2 expirogram. Adjustable ventilation parameters such as tidal volume (VT), respiratory rate (RR), positive end-expiratory pressure (PEEP), and the ratio of inspiratory to expiratory were adjusted by utilizing the phase III slopes of CO2 expirogram, which together with the relationship between the changes of CO2 expirogram and the selective lung recruitment.

During OLV, the phase III slopes of CO2 expirogram in patients with pulse oxymetry (SpO2) decreased less than 93% after the OLV-PP, and were absolutely different from that during TLV. After OLV-AP, the phase III slopes of CO2 expirogram and SpO2 were similar to those during TLV. During OLV, however, parameters of ventilation setting in both OLV-PP and OLV-AP are obviously different.

This study indicates that alveolar recruitment by utilizing CO2 expirogram probably improves SpO2 level during one-lung ventilation.

No MeSH data available.