Randomized double-blind trial comparing effects of low-flow vs high-flow anesthesia on postoperative lung functions
T Krishna Prasad1, N Gnanasekar1, K Soundarya Priyadharsini2
1Department of Anesthesiology, Shri Sathya Sai Medical College and Research Institute, (Sri Balaji Vidyapeeth, Deemed to be University), Kancheepuram, Tamil Nadu, India.
Journal of Anaesthesiology, Clinical Pharmacology
|April 12, 2021
Summary
Low-flow anesthesia has similar pulmonary effects to high-flow anesthesia in patients undergoing surgery. Vital capacity, inspiratory reserve volume, and expiratory flow rates were comparable between the two anesthesia methods.
Area of Science:
- Anesthesiology
- Pulmonary Medicine
- Surgical Care
Background:
- Low-flow anesthesia is increasingly used, but its impact on lung function requires further investigation.
- Limited studies compare pulmonary function measurements between low-flow and high-flow anesthesia techniques.
- This study addresses the gap by evaluating postoperative pulmonary function in patients receiving different anesthesia flow rates.
Purpose of the Study:
- To compare the postoperative pulmonary functions of patients undergoing peripheral surgeries under low-flow versus high-flow anesthesia.
- To evaluate the effects of different anesthesia flow rates on vital capacity (VC), inspiratory reserve volume (IRV), and peak expiratory flow rates (PEFR).
Main Methods:
- A prospective, randomized, double-blind study involving 110 patients undergoing peripheral surgeries.
- Patients were allocated to either low-flow (0.5L O2 + 0.5L N2O + 3.5% Sevoflurane) or high-flow (2L O2 + 2L N2O + 2% Sevoflurane) anesthesia.
- Postoperative pulmonary function tests (VC, IRV, PEFR) were compared to preoperative values.
Main Results:
- No statistically significant differences were observed in VC, IRV, or PEFR between the low-flow and high-flow anesthesia groups postoperatively.
- Measurements including single breath count, breath holding time, and respiratory rates also showed no significant variations between groups.
- The P-values for VC, IRV, and PEFR were 0.173, 1.00, and 0.213, respectively.
Conclusions:
- Low-flow anesthesia demonstrates comparable pulmonary effects to high-flow anesthesia in patients undergoing elective surgeries.
- Anesthesia flow rate does not appear to significantly impact key postoperative pulmonary function parameters in this patient cohort.
- These findings suggest low-flow anesthesia is a viable alternative with similar respiratory outcomes.
