Acute hyperventilation increases the central venous-to-arterial PCO2 difference in stable septic shock patients - 08/01/26
, Usman Mohammad 2
, Malcolm Lemyze 1, 2
, Mehdi Meddour 1
, Marie Jonard 1, 2
, Florent Pepy 1
, Gaelle Gasan 1
, Stephanie Barrailler 1
, Johanna Temime 1
, Nicolas Vangrunderbeeck 1
, Laurent Tronchon 1
, Didier Thevenin 1, 2 
Abstract |
Background |
To evaluate the effects of acute hyperventilation on the central venous-to-arterial carbon dioxide tension difference (∆PCO 2 ) in hemodynamically stable septic shock patients.
Methods |
Eighteen mechanically ventilated septic shock patients were prospectively included in the study. We measured cardiac index (CI), ∆PCO 2 , oxygen consumption (VO 2 ), central venous oxygen saturation (ScvO 2 ), and blood gas parameters, before and 30 min after an increase in alveolar ventilation (increased respiratory rate by 10 breaths/min).
Results |
Arterial pH increased significantly (from 7.35 ± 0.07 to 7.42 ± 0.09, p < 0.001) and arterial carbon dioxide tension decreased significantly (from 44.5 [41–48] to 34 [30–38] mmHg, p < 0.001) when respiratory rate was increased. A statistically significant increase in VO 2 (from 93 [76–105] to 112 [95–134] mL/min/m 2 , p = 0.002) was observed in parallel with the increase in alveolar ventilation. While CI remained unchanged, acute hyperventilation led to a significant increase in ∆PCO 2 (from 4.7 ± 1.0 to 7.0 ± 2.6 mmHg, p < 0.001) and a significant decrease in ScvO 2 (from 73 ± 6 to 67 ± 8%, p < 0.001). A good correlation was found between changes in arterial pH and changes in VO 2 ( r = 0.67, p = 0.002). Interestingly, we found a strong association between the increase in VO 2 and the increase in ∆PCO 2 ( r = 0.70, p = 0.001).
Conclusions |
Acute hyperventilation provoked a significant increase in ∆PCO 2 , which was the result of a significant increase in VO 2 induced by hyperventilation. The clinician should be aware of the effects of acute elevation of alveolar ventilation on ∆PCO 2 .
Le texte complet de cet article est disponible en PDF.Keywords : Acute hyperventilation, Oxygen consumption, Central venous-to-arterial CO 2 tension gap , Central venous oxygen saturation, Septic shock
Plan
Vol 7 - N° 1
Article 31- 2017 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
