PYCNOGENOL in chronic venous insufficiency.

The aim of out study was to investigate the efficacy of Pycnogenol - a French maritime pine bark extract - in the treatment of chronic venous insufficiency (CVI). The study consisted of a double-blind phase - in which 20 patients were recruited and randomly treated with placebo or Pycnogenol (100 mg 2 3/day for 2 months) - and an open phase - in which other 20 patients were treated with Pycnogenol at the same dose schedule. In total, 40 patients were enrolled; 30 of them were treated with Pycnogenol and 10 with placebo. Pycnogenol significantly improved the legs' heaviness and subcutaneous edema; the venous pressure was also significantly reduced by the Pycnogenol treatment, thus adding further clinical evidence to its therapeutic efficacy in patients with CVI. Pycnogenol was effective, probably by either stabilizing the collagenous subendothelial basal membrane or scavenging the free radicals, or by a combination of these activities. Clinically, capillary leakage, perivascular inflammation and subcutaneous edema were all reduced. The safety of use of Pycnogenol is demonstrated by the lack of side effects or changes in blood biochemistry and hematologic parameters. Pycnogenol can be therefore recommended both for prevention and treatment of CVI and related veno-capillary disturbances.     

Effective vascular compliance and venous diameter in dogs.

Total effective vascular compliance was measured repeatedly in open-chest dogs without circulatory arrest, utilizing a closed-circuit venous bypass system with a constant cardiac output. Mutual inductance coils were used to measure the diameter of the inferior vena cava above the diaphragm at the position where the pressure change was recorded during a volume load (lambde V). In all experiments, there was a relationship which tended to be curvilinear between the diameter of the inferior vena cava and the venous pressure before lambde V. No relationship was demonstrated between the initial diameter or pressure and the calculated effective vascular compliance. During aortic constriction or infusion of noradrenaline, the effective compliance was reduced in value at any given initial venous diameter and pressure. An unaltered venous diameter and plasma volume excluded the possibility of a large change in initial venous volume as a cause of the observed changes in compliance during aortic constriction or during infusion of noradrenaline. A relationship was observed between compliance and calculated venous wall tension so that as the wall tension, developed during a fixed volume load, increased, there was an associated reduction in compliance. These results demonstrate that the measurement of effective compliance provides an assessment of combined active and passive venous wall tension and venous tone.     

Peripherally inserted central venous catheters. Low-risk alternatives for ongoing venous access.

We prospectively evaluated the use of peripherally inserted central venous catheters to provide ongoing venous access in general medical and surgical patients in a Department of Veterans Affairs medical center. Between 1985 and 1988 trained nurses successfully inserted 393 catheters in 460 suitable patients (an 85.4% success rate). Correct catheter tip placement in the superior vena cava was documented in 359 of the 393 (91.3%) catheter insertions, but an additional 30 catheters were in a position deemed adequate for the intended use. The mean duration of catheter use was 27.6 +/- 5.2 (1 standard deviation) days (median 20 days, range 1 to 370 days). A total of 65 patients left the hospital with catheters in place, with the mean length of catheter use at home being 36.2 +/- 6.0 days (range 2 to 266). In all, 79% of the catheters were in use until the successful completion of therapy or patient death; catheter-related complications led to premature catheter removal in the remaining 21%. Catheter-related complications included bland phlebitis (8.2%), occlusion (8.2%), local infection (3.6%), bacteremia or fungemia (2.1%), mechanical failure or rupture (2.6%), venous thrombosis (0.7%), and other (3.3%). One patient required vein excision for the management of suppurative phlebitis, but no deaths were attributed to catheter use. This study illustrates the use and safety of peripherally inserted central venous catheters to provide reliable vascular access over prolonged periods in an elderly veteran population. At our facility, percutaneous central venous catheters and surgically implanted (Hickman or Broviac) catheters are now reserved for use in patients in whom peripherally inserted catheters cannot be placed.     

Cardiac tamponade and central venous catheters.

An analysis of the reports on 16 patients who developed cardiac tamponade, complicating the use of central venous catheters, showed that 14 died. The two survivors were treated by removal of the catheter and needle aspiration of the pericardial fluid. Some patients complained of warning symptoms such as nausea, pain, and dyspnoea, and the combination of tachycardia, hypotension, and raised venous pressure was common. We suggest that awareness of the hazard, radiographic visualization of the catheter tip, and expeditious treatment would reduce the mortality.