Case–control evaluation of the impact of below 20 mmHg elastic compression stockings on lower limb volume serial variations in standardized flights

Background: Graduated compression stocking (GCS) use during flights demonstrated to positively impact leg oedema. Nevertheless, these data were collected in a single flight, mainly at the ankle, and using greater than 20 mmHg GCS. This investigation reports data from 16 flights in which the same passenger’s leg circumferences variation were assessed wearing non-graduated ankle-sock or a below-knee 15–20 mmHg GCS. Methods: The limb was divided by the circumferences in eight sectors, every 4 cm, labelled from 1 to 8, starting from the ankle up. The assessment was done at the take-off and after a 4-h flight time, for a total of 16 flights. The subject used non-graduated ankle socks (elastic band at 4 cm from B-point) during the outgoing flight and below-knee GCS (15–20 mmHg) during the return flight. Interface pressure was assessed at the ankle point of minimum girth (B) and ascending proximally every 4 cm (B+cm) for the GCS, and at B and at the elastic band level (B + 4 cm) for the sock. Results: GCS interface pressure was 13.3 ± 2.5 mmHg in B and 18.1 ± 2.4 mmHg in B + 4 cm. The sock interface pressure was 3.1 ± 0.7 mmHg in B and 8.1 ± 0.9 mmHg at the band level (B + 4 cm). Socks led to a significant total volume increase (117.3 ± 25.8 mL; 5.2% ±1.1%; P < 0.0001). GCS led to a non-significant total volume decrease (–3.1 ± 14.4 mL; –0.1 ± 0.6%; P = 0.3964) and did not allow for volume increase. The different sectors showed a heterogeneous volume variation, not following a precisely graduated or progressive compression profile. Conclusions: Leg oedema following a 4-h flight is controlled by <20 mmHg GCS. Leg fluids, with and without GCS, are mobilized in a non-graduated profile from the ankle to the knee after prolonged sitting on a plane.