Serial arterial blood gas monitoring during deep sedation for left atrial ablation detected severe hypercapnia in 21.6% of patients, predicted by baseline pCO2 (OR 0.60; 95% CI 0.41-0.89; P=0.005).
Cohort (n=102)
No
Does serial ABG monitoring at 15-minute intervals detect early respiratory and metabolic deterioration in deeply sedated patients undergoing left atrial ablation?
Serial ABG monitoring during deep sedation for left atrial ablation reveals frequent early respiratory and metabolic deterioration, suggesting traditional non-invasive monitoring may be insufficient.
Effect estimate: OR 0.60 (95% CI 0.41-0.89)
p-value: p=0.005
Abstract Background Deep sedation is widely used in left atrial ablation, especially for pulsed field ablation (PFA), which requires deeper sedation than traditional methods. However, there is no standardized sedation protocol across Europe. While some centers use conscious sedation, others rely on deep sedation, often without sufficient monitoring for early respiratory and metabolic instability. The role of serial arterial blood gas (ABG) analysis in detecting these complications remains unclear. Purpose This study aimed to evaluate whether serial ABG monitoring at 15-minute intervals could detect early respiratory and metabolic deterioration in deeply sedated patients undergoing left atrial ablation. Additionally, we assessed whether ABG findings could guide sedation adjustments and ventilation support to improve patient safety. Methods A retrospective study of 102 patients undergoing left atrial ablation (62 PFA, 38 RF, 2 cryoablation) was conducted at a single center. Mean age was 65.8 ± 9.7 years; 41.2% were female. Deep sedation with midazolam, fentanyl, and propofol (mean dose 1101 ± 544 mg) targeted a RASS score of -4. Continuous invasive blood pressure monitoring and serial ABGs (every 15 minutes) assessed pH, pCO₂, pO₂, and base excess (BE). Hemodynamic instability was defined as systolic BP 90 mmHg or MAP 65 mmHg for 2 minutes. Respiratory acidosis was pH 7.35 (severe 7.20), hypercapnia as pCO₂ 45 mmHg (severe 60 mmHg), and metabolic acidosis as BE -2 mmol/L. Sedation adjustments, ventilation support, and sodium bicarbonate administration were guided by ABG results. Results Serial ABGs showed significant respiratory and metabolic deterioration. pH declined progressively (p 0.001), with major reductions in the first 45 minutes. pCO₂ increased significantly (p 0.001), peaking between 15 and 45 minutes before stabilizing. Severe hypercapnia (pCO₂ 60 mmHg) occurred in 21.6% of patients. BE also decreased significantly (p 0.001), indicating metabolic acidosis, with stabilization after 45 minutes. Sodium bicarbonate was used in 22.2% of patients. Logistic regression identified baseline pCO₂ as a predictor of severe hypercapnia (p = 0.005, OR = 0.60, 95% CI: 0.41-0.89). Lower pH at 15 minutes strongly correlated with hypercapnia risk (p = 0.014, OR = 3.41 × 10⁻²³). BMI showed a trend (p = 0.089) but was not statistically significant. LVEF, obesity, COPD, and heart failure were not significant predictors. Conclusion Serial ABG monitoring detects early respiratory and metabolic deterioration during deep sedation for left atrial ablation. Significant pH, pCO₂, and BE changes occur within the first 45 minutes, with over 20% of patients requiring ventilation support. Baseline pCO₂ and pH at 15 minutes predict hypercapnia risk, while traditional non-invasive monitoring may be insufficient. Given PFA’s increasing use, integrating ABG monitoring into sedation protocols may improve patient safety.
Buia et al. (Sat,) conducted a cohort in Left atrial ablation under deep sedation (n=102). Serial arterial blood gas (ABG) monitoring was evaluated on Severe hypercapnia (pCO2 > 60 mmHg) predicted by baseline pCO2 (OR 0.60, 95% CI 0.41-0.89, p=0.005). Serial arterial blood gas monitoring during deep sedation for left atrial ablation detected severe hypercapnia in 21.6% of patients, predicted by baseline pCO2 (OR 0.60; 95% CI 0.41-0.89; P=0.005).