Prospective Randomized Controlled Trial to Analyze the Effects of Intermittent Pneumatic Compression on Edema Following Autologous Femoropopliteal Bypass Surgery

Background: Patients who undergo autologous femoropopliteal bypass surgery develop postoperative edema in the revascularized leg. The effects of intermittent pneumatic compression (IPC) to treat and to prevent postreconstructive edema were examined in this study. Methods: In a prospective randomized trial, patients were assigned to one of two groups. All patients suffered from peripheral arterial disease, and all were subjected to autologous femoropopliteal bypass reconstruction. Patients in group 1 used a compression stocking (CS) above the knee exerting 18 mmHg (class I) on the leg postoperatively for 1 week (day and night). Patients in group 2 used IPC on the foot postoperatively at night for 1 week. The lower leg circumference was measured preoperatively and at five postoperative time points. A multivariate analysis was done using a mixed model analysis of variance. Results: A total of 57 patients were analyzed (CS 28; IPC 29). Indications for operation were severe claudication (CS 13; IPC 13), rest pain (10/5), or tissue loss (7/11). Revascularization was performed with either a supragenicular (CS 13; IPC10) or an infragenicular (CS 15; IPC 19) autologous bypass. Leg circumference increased on day 1 (CS/IPC): 0.4%/2.7%, day 4 (2.1%/6.1%), day 7 (2.5%/7.9%), day 14 (4.7%/7.3%), and day 90 (1.0%/3.3%) from baseline (preoperative situation). On days 1, 4, and 7 there was a significant difference in leg circumference between the two treatment groups. Conclusions: Edema following femoropopliteal bypass surgery occurs in all patients. For the prevention and treatment of that edema the use of a class I CS proved superior to treatment with IPC. The use of CS remains the recommended practice following femoropopliteal bypass surgery

Acrolein inhalation alters arterial blood gases and triggers carotid body-mediated cardiovascular responses in hypertensive rats

CONTEXT: Air pollution exposure affects autonomic function, heart rate, blood pressure and left ventricular function. While the mechanism for these effects is uncertain, several studies have reported that air pollution exposure modifies activity of the carotid body, the major organ that senses changes in arterial oxygen and carbon dioxide levels, and elicits downstream changes in autonomic control and cardiac function. OBJECTIVE: We hypothesized that exposure to acrolein, an unsaturated aldehyde and mucosal irritant found in cigarette smoke and diesel exhaust, would activate the carotid body chemoreceptor response and lead to secondary cardiovascular responses in rats. MATERIALS AND METHODS: Spontaneously hypertensive (SH) rats were exposed once for 3 h to 3 ppm acrolein gas or filtered air in whole body plethysmograph chambers. To determine if the carotid body mediated acrolein-induced cardiovascular responses, rats were pretreated with an inhibitor of cystathionine γ-lyase (CSE), an enzyme essential for carotid body signal transduction. RESULTS: Acrolein exposure induced several cardiovascular effects. Systolic, diastolic and mean arterial blood pressure increased during exposure, while cardiac contractility decreased 1 day after exposure. The cardiovascular effects were associated with decreases in pO(2), breathing frequency and expiratory time, and increases in sympathetic tone during exposure followed by parasympathetic dominance after exposure. The CSE inhibitor prevented the cardiovascular effects of acrolein exposure. DISCUSSION AND CONCLUSION: Pretreatment with the CSE inhibitor prevented the cardiovascular effects of acrolein, suggesting that the cardiovascular responses with acrolein may be mediated by carotid body-triggered changes in autonomic tone. (This abstract does not reflect EPA policy.