Intermittent compression units for severe post-phlebitic syndrome: a randomized crossover study

Background: Although uncommon, severe post-phlebitic syndrome may be associ ated with persistent, intractable pain and swelling that interfere with wor k and leisure activities. This study was performed to determine whether int ermittent compression therapy with an extremity pump benefits patients with this condition and, if so, whether the benefit is sustained. Methods: The study was a randomized crossover trial. Over the period 1990 t o 1996, ail patients in the clinical thromboembolism program of an Ontario teaching hospital who had a history of deep vein thrombosis and intractable symptoms of post-phlebitic syndrome were recruited into the study. The stu dy involved using an extremity pump twice daily for a total of 2 months (20 minutes per session). The patients were randomly assigned to use either a therapeutic pressure (50 mm Hg) or a placebo pressure (15 mm Hg) for the fi rst month. For the second month, the patients used the other pressure. A qu estionnaire assessing symptoms and functional status served as the primary outcome measure and was administered at the end of each 1-month period. A s ymptom score was derived by summing the scores for individual questions. At the end of the 2-month study, patients were asked to indicate their treatm ent preference and to rate the importance of the difference between the 2 p ressures. Treatment was considered successful if the patient preferred the therapeutic pressure and stated that he or she would continue using the ext remity pump and that the difference between the therapeutic and placebo pre ssures was of at least slight importance. All other combinations of respons es were considered to represent treatment failure. Patients whose treatment was classified as successful were offered the opportunity to keep the pump and to alter pressure, frequency and duration of pump use to optimize symp tom management. In July 1996 the authors contacted all study participants w hose treatment had been classified as successful to determine whether they were still using the pump and, if so, whether they were still deriving bene fit. Results: In total 15 consecutive patients (12 women and 3 men) were enrolle d in the study. The symptom scores were significantly better with the thera peutic pressure (mean 16.5) than with the placebo pressure (mean 14.4) (pai red t-test, p = 0.007). The treatment for 12 of the patients (80%, 95% conf idence interval 52% to 96%) was considered successful. Of these, 9 patients continued to use the pump beyond the crossover study and to derive benefit . Interpretation: The authors conclude that a trial of pump therapy is worthw hile for patients with severe post-phlebitic syndrome and that a sustained beneficial response can be expected in most such patients.