Respiratory Functions, Aerobic Capacity and Quality of Life in Chronic Venous Insufficiency

The 30-second Sit-to-Stand Test was used on a chair to determine lower extremity strength and functional mobility. Rikli et al. designed a 30-second sit-to-stand test in 1999 to evaluate individuals' dynamic balance and physical fitness lower extremity neuromuscular function levels. During the test, the individual sat on a chair without back support, arms crossed over the body, which was the initial sitting position. Then, the individual stood up and sat down repeatedly for 30 seconds. The total number of correct standing ups during this period was recorded. A higher number of repetitions indicates better physical performance. Performing less than 10 repetitions of the movement in 30 seconds indicates lower extremity weakness.

The 6-minute walking test was performed according to ATS criteria and twice on the same day, half an hour apart. Before the test, the subjects rested for at least 10 minutes, and before and after the test, oxygen saturation, heart rate, blood pressure, respiratory rate, dyspnea perception, fatigue and leg fatigue were recorded. Oxygen saturation was assessed using a portable pulse oximeter, heart rate using a heart rate monitor, blood pressure using a sphygmomanometer, respiratory rate using a count of the breaths taken per minute, and fatigue, leg fatigue and dyspnea perception using the Modified Borg Scale. The starting and ending points in the corridor where the test would be performed were determined and marked with cones. The subjects were asked to walk as fast as they could at their own walking speed for 6 minutes on a 30-meter straight corridor. In order to encourage the subjects, standard expressions were used for each minute during the test and the 6-MWT distance was recorded

A spirometer was used to evaluate respiratory functions. Before the test, individuals rested for 15 minutes and during the rest, participants were told how to do the test, how to use a mouthpiece, when to inhale and exhale, and how to complete the test with maximum effort, and then they were shown a practical demonstration. While individuals were sitting in a comfortable position in a chair with a back, a clip was placed on their noses and they were asked to bite the mouthpiece with their teeth and close their lips so that they would not allow air to escape. During the test, individuals were asked to exhale until there was no air left in their lungs and they were allowed to follow the time on the monitor. The tests were to be performed by the participants at least 3 times and it was ensured that the expiration time was at least 6 seconds and the plateau time was 1 second.

Respiratory muscle strength was assessed with a spirometer. The pressure was recorded during a few seconds of maximal inspiration (Müller maneuver) or expiration (Valsalva maneuver) through the mouth. Maximum static inspiratory pressure was measured by having the patients take a rapid and deep inspiration at the residual volume after maximum expiration. Maximum static expiratory pressure was measured by having the patients take a rapid and deep expiration at the total lung capacity after maximum inspiration. The tests were performed in the sitting position using a nose clip. The patients were verbally encouraged to achieve the best strength. The measurement was repeated until a valid value was obtained in the patients. If there was a difference of more than 5% or 5 cmH₂O between the consecutive measured values, the measurement was repeated.

The Chronic Venous Insufficiency Quality of Life Questionnaire (CIVIQ) was used to assess quality of life. The questionnaire consists of 20 questions specific to Chronic Venous Insufficiency. It consists of 4 parameters questioning physical, psychological, social status and pain. Each question is scored according to a 5-item Likert scale. Higher scores indicate better quality of life. The Turkish validity and reliability study was conducted by Özdemir et al.

Pain intensity was measured with the Numerical Rating Scale (SDS). The maximum level of pain felt at rest and during activity was scored from 0 to 10. A value of "0" indicates no pain, and a value of "10" indicates pain of the worst intensity. The reliability and validity of the SDS was proven by Cleland et al., and the intraclass correlation coefficient (ICC) value was reported as 0.76.

The edema in the lower extremity was assessed by measuring the circumference with a tape measure. Each leg was recorded separately and the difference was calculated. A flexible, non-elastic, 7 mm wide standard tape measure with a sensitivity level of 0.1 cm was used in circumference measurements. The "0" (zero) end of the tape measure was wrapped around the area to be measured, with the other end in the left hand and the number on the "0" (zero) point noted. During the measurement, care was taken to ensure that the "0" (zero) point of the tape measure and the measurement number were side by side, not on top of each other, and the measurement was performed with the patient in the supine position in order to ensure standardization in each measurement. The circumference measurement values for each individual were converted to volumetric measurements by placing them in the Frustrum formula (truncated cone method).