Clinical evidence of subcutaneous CO2 insufflations:: A systematic review

Objective: To evaluate the evidence of clinical effectiveness of subcutaneous CO2 insufflations (SCIs). Study location: The entire databases of MEDLINE, EMBASE Excerpta Medica (Field: Rehabilitation and Physical Medicine) and the Cochrane Library were screened for data up to August 1999. In addition, other potentially relevant journals were handsearched and references were checked. Study selection: Uncontrolled observational trials (UCOTs) with sample sizes of at least n = 100, and controlled clinical trials (CCTs) and randomized controlled trials (RCTs) were included. Outcomes had to be patient-centered. English-, Czechoslovakian-, and German-language papers were considered. Data analysis: For all study types, a criteria-based analysis was performed. For controlled trials only, quality was quantitatively assessed with the Jadad and Maastricht Scales. Results: Thirteen studies (5 RCTs, 2 CCTs, and 6 UCOTs) were included. Mean scores on the Jadad and Maastricht Scales were 2 (Maximum 5) and 37 (Maximum 100), respectively. SCIs were found to be effective in addition to standard physical therapy in "peripheral arterial occlusive disease" (2 RCTs) and "stable angina pectoris" (1 RCT) and superior to sham needling for migraine headaches (1 RCT). There were no differences among SCIs and CO2 gas baths (1 RCT) or combined interventions, including SCIs (2 CCTs). All 6 UCOTs showed marked longitudinal effects. Conclusions: The low number and quality of the available studies precludes firm conclusions on the clinical effectiveness of SCIs.