The following is a summary of “Oxygen inhalation decreases the central venous pressure in adult patients late after Fontan operations,” published in the March 2024 issue of Cardiology by Sakamoto et al.
After Fontan operations, patients often experience elevated central venous pressure (CVP) and decreased arterial oxygen saturation (SaO2), which are linked to long-term morbidity and mortality. Oxygen inhalation therapy has been proposed as a potential solution to increase SaO2 and reduce elevated CVP, yet prior studies haven’t validated this theory.
Researchers conducted a retrospective study to assess the immediate impact of oxygen inhalation on the hemodynamics of adult patients who underwent Fontan operations using cardiac catheterization.
They included 58 consecutive adult patients (median age: 30 years; female: n=24) who underwent Fontan operations. During oxygen inhalation (2 L/min), hemodynamic changes with a nasal cannula were evaluated via cardiac catheterization. Patients were divided into responders (>2 mmHg reduction in CVP) and non-responders (≤2 mmHg reduction) based on median values. Clinical characteristics of oxygen inhalation responders were investigated using uni- and multivariate analyses.
The results showed that SaO2 increased significantly from 93.3% (91.3–94.5%) to 97.5% (95.2–98.4%) (P<0.001), while CVP decreased significantly from 12 mmHg (11–14 mmHg) to 10 mmHg (9–12 mmHg) (P<0.001) after oxygen inhalation. A weak but significant correlation was found between the increase in SaO2 and the decrease in CVP (R = 0.29, P=0.025). Pulmonary blood flow increased from 4.1 L/min (3.5–5.0 L/min) to 4.4 L/min (3.7–5.3 L/min) (P=0.007), while systemic blood flow remained unchanged. Multivariate analysis revealed that a higher baseline CVP was associated with a greater decrease in CVP (>2 mmHg) following oxygen inhalation.
Investigators concluded that oxygen inhalation in Fontan patients improved SaO2 and lowered CVP, particularly in those with initially high CVP.
Source: journal-of-cardiology.com/article/S0914-5087(24)00036-4/abstract
