Incidence of deep venous thrombosis associated with femoral venous catheterization.

OBJECTIVE: To determine in adult medical patients the incidence of deep venous thrombosis (DVT) resulting from femoral venous catheterization (FVC). METHODS: A prospective, observational study was performed at a 420-bed community teaching hospital. Heparin-coated 7-FR cm femoral venous catheters were inserted unilaterally into a femoral vein. Each contralateral leg served as a control site. Age, gender, number of FVC days, DVT risk factors, administration of DVT prophylaxis, and DVT formation and site were tabulated for each patient. Venous duplex sonography was performed bilaterally on each patient within 7 days of femoral venous catheter removal. RESULTS: Catheters were placed in 29 men and 13 women. Femoral DVT was identified by venous duplex sonography in 11 (26.2%) of the FVC legs and none (0%) in the control legs. Posterior tibial and popliteal DVT was identified in both the FVC and control legs of 1 patient. DVT formation at the site of FVC insertion was highly significant (p = 0.005). There were no statistically significant associations with age (p = 0.42), gender (p = 0.73), number of DVT risk factors (p = 0.17), number of FVC days (p = 0.89), or DVT prophylaxis (p = 0.99). CONCLUSION: Placement of femoral catheters for central venous access is associated with a significant incidence of femoral DVT as detected by venous duplex sonography criteria at the site of femoral venous catheter placement. Physicians must be aware of this risk when choosing this vascular access route for adult medical patients. Further studies to assess the relative risk for DVT anf its clinical sequelae when using the femoral vs other central venous catheter routes are indicated.

The in situ saphenous vein bypass graft: radiologic aspects.

The use of the in situ saphenous vein for bypassing arterial occlusions in the lower extremities appears to have a higher patency rate than other bypass procedures but presents unique technical problems, such as lysing valves and occluding venous tributaries. Forty-four patients undergoing in situ bypasses had preoperative arteriograms. Special attention was paid to the small runoff vessels around the ankle, which are not suitable for reversed bypass procedures but may be adequate for in situ bypasses. Eight patients also had preoperative saphenous venograms, which revealed surgically important abnormalities in six cases. Postoperative arteriograms obtained within 2 weeks in 10 patients and within 2-12 months in 15 patients revealed persistent arteriovenous fistulas in four patients, stenoses in nine, occlusions in five, and progressive disease in the nonbypassed arteries in five patients. Early recognition of these problems led to 11 surgical repairs; nine repairs used the interventional radiologic procedures of balloon angioplasty, transcatheter embolization, and catheter thrombolysis. In this group of 44 patients, five patients died with patent bypasses and three patients required amputation despite functioning bypasses. Only four amputations were attributed to bypass failure. This low figure may be due to the close cooperation of the vascular surgeons and the vascular radiologists in dealing with these complicated cases.

Sequential pneumatic compression for lymphedema. A controlled trial.

We examined prospectively the effect of a new compression device for lymphedema, which utilizes a short duration and high-pressure cycle, that provides a sequential milking pattern to the limb through multiple compartments. Twenty-five patients (seven patients for upper-extremity and 18 for lower-extremity problems) underwent 24 hours of treatment. All extremities showed a decrease in circumferential measurements with the maximal reduction occurring at the wrist (45%) for the upper extremities and at the mid-calf (47%) for the lower extremities. Lower-extremity leg volume was reduced by 45%. Despite the high pressures no elevation in serum muscle enzyme levels was noted. This device reduced lymphedematous limbs rapidly and safely.

Above-knee polytetrafluoroethylene femoropopliteal bypass graft: Is it a reasonable alternative to the below-knee reversed autogenous vein graft?

To determine whether an above-knee polytetrafluoroethylene (AK-PTFE) femoropopliteal bypass graft might be an acceptable alternative to a below-knee reversed autogenous saphenous vein (BK-ASV) bypass graft, we compared 51 AK-PTFE grafts to 39 concurrently performed BK-ASV grafts. All patients were staged by preoperative noninvasive vascular laboratory criteria into limiting claudication or limb salvage groups and by intraoperative arteriography according to degree of runoff. There was no significant difference in the primary graft patency at 36 months between the AK-PTFE group (63%) and the BK-ASV group (72%). Secondary graft patency among the AK-PTFE group was improved by minor distal graft revision to 88% at 36 months. The preoperative noninvasive hemodynamic evaluation status was an influential factor; the graft patency rate among the patients with limiting claudication was superior to that among the limb salvage group, but the degree of runoff as shown by intraoperative angiography did not appear to have an effect on cumulative patency. Resting Doppler ankle/brachial artery pressure ratios did not predict subsequent occlusion of AK-PTFE grafts. Atherosclerosis is a progressive and systemic disease that frequently involves both the coronary and tibial vessels. AK-PTFE spares autogenous saphenous vein so that it can be reserved for use in coronary artery bypass or in subsequent treatment of more distal tibial vessel disease.

Altered thyroid hormone levels in bacterial sepsis: the role of nutritional adequacy.

Depressed triiodothyronine and elevated reverse triiodothyronine levels are commonly seen in patients with acute and chronic illness and in patients receiving markedly hypocaloric diets. To investigate the role of nutritional adequacy in causing the altered thyroid hormone levels found in severe illness, we studied patients with bacterial sepsis who were receiving a variety of nutritional regimens. Thirteen patients received only 5% dextrose in water (600-1000 kcal/day), 7 of whom were in shock. Seven patients received total parenteral nutrition (2500-3500 kcal/day). Analysis of thyroid hormone levels in these groups and in controls shows that a large component of the alteration in thyroid hormone levels found in patients with severe illness is due to the caloric deprivation associated with such severe illness.

Investigation of factors determining the optimal glucose infusion rate in total parenteral nutrition.

We have used the primed constant infusion of U-13C-glucose to study glucose metabolism during conventional total parenteral nutrition (TPN) in five postoperative surgical patients. Glucose production from nonrecycled carbon sources was suppressed to 17% of the basal level at the lowest rate of glucose infusion tested (4 mg/kg x min). Subsequent increases in glucose infusion rate had minimal effect in further suppressing glucose production. Additional nitrogen-sparing effects of glucose when glucose is infused at rates in excess of 4 mg/kg x min must therefore be derived from oxidation of the infused glucose. An increase in the infusion rate from 4 mg/kg x min to 7 mg/kg x min was associated with an increased rate of glucose oxidation, but a further increase in glucose infusion rate (9 mg/kg x min) was without significant effect on glucose oxidation. As the rate of TPN administration (glucose and amino acids) increased, both metabolic rate and RQ rose significantly. Our calculations indicate that the high RQ's observed during the highest glucose infusion rate (X = 1.13) could be attributed to the synthesis of fat from infused glucose, and that about 30% of the increase in VO2 above the basal level could also be attributed to fat synthesis. The progressive increase in the ability to clear glucose from the blood that occurred as TPN progressed was not due to an increase in the rate of oxidation of glucose; we found no correlation between glucose clearance and glucose oxidation.