Effect of stockings on calf muscle oxygenation in patients with venous insufficiency

Background: The mechanism of action of stockings in symptom relief and treatment of venous insufficiency is still inadequately understood. Near‐infrared spectroscopy (NIRS) provides continuous non‐invasive monitoring of changes in tissue oxygen reserves and availability, by monitoring oxyhaemoglobin (HbO 2 ), deoxyhaemoglobin (HbD) and cytochrome oxidase (CtO 2 ). This study investigated the effect of stockings on calf muscle oxygenation during exercise using NIRS in patients with venous insufficiency. Methods: Ten patients (mean(s.e.m.) age 56(5) years, seven women) with venous insufficiency participated in the study. Patients rested in a supine posture for 20 min. NIRS probes were attached to the calf at interoptodes spacing of 4 cm and initialized to zero. Calf oxygenation was continuously monitored during standing followed by a 5‐min slow walk at 1·6 km h −1 with and without stockings chosen at random. A 30‐min rest in the supine position was allowed between stockings. Pulse rate and peripheral oxygen saturation were monitored continuously by a pulse oximeter. Results: Mean HbO 2 concentration, HbD and mitochondrial oxygenation (CtO 2 ) increased significantly with stockings during exercise.No stocking Class 1 Class 2 Class 3Mean HbO 2 (µmol l −1 ) 2·88(2·39) 4·29(2·41) 4·52(2·43) 5·83(2·44) ‡ Mean HbD (µmol l −1 ) −8·53(2·10) −4·20(2·38) * −3·19(3·21) † −1·06(3·34) * Mean CtO 2 (µmol l −1 ) 0·73(0·65) 0·93(0·60) 1·36(0·65) * 1·71(0·72) *Values are mean(s.e.m.). HbD, oxygenation index. * P ≤ 0·002 † P = 0·01 ‡ P = 0·03 versus no stocking (paired t test)Conclusion: Graduated compression stockings may achieve beneficial effects by improving calf muscle oxygenation during exercise in patients with venous insufficiency. © 2000 British Journal of Surgery Society Ltd