Oh C; Department of Anesthesiology Daejeon, 35015, Korea.
Park S; Lee S; Chong Y;et al

BMC Anesthesiology. 26(1), 2026 May 14.

BACKGROUND: Oxygen consumption (VO2) is a core element of hemodynamic
physiology and the metabolic counterpart to oxygen delivery. Modern
anesthesia machines enable real-time intraoperative VO2 estimation, yet
its relationship with preoperative metabolic capacity, as characterized by
cardiopulmonary exercise testing (CPET), has not been directly examined.

METHODS: This study analyzed preoperative CPET and intraoperative data
from adult patients >= 20 undergoing lung resection under general
anesthesia. Intraoperative VO2 was estimated from minute ventilation and
inspired and end-tidal oxygen fractions. Preoperative and intraoperative
VO2 were summarized, and associations between baseline VO2 and
intraoperative suppression were assessed.

RESULTS: Data from 32 patients were analyzed. Preoperative VO2 at rest,
anaerobic threshold, and peak exercise were 1.6 +/- 0.4, 5.1 +/- 1.9, and
6.1 +/- 1.7 metabolic equivalents (METs), respectively. The reduction from
resting to intraoperative VO2 (-29.0 +/- 19.4%) showed a strong
correlation with resting VO2 (r = 0.770, p < 0.001). Consequently,
regardless of preoperative resting VO2, intraoperative VO2 converged to a
relatively narrow range, averaging 1.1 +/- 0.2 METs.

CONCLUSIONS: In patients undergoing lung resection, intraoperative VO2
converged to approximately 1 MET under general anesthesia, largely
independent of preoperative resting metabolism. The clinical implications
of this observation remain unclear and warrant investigation in larger
prospective studies incorporating concurrent measurements of oxygen
delivery and clinical outcomes.