Jean-Christophe Farkas

Single- versus triple-lumen central catheter-related sepsis: A prospective randomized study in a critically ill population☆

PURPOSE A prospective randomized study was conducted over a 23-month period in an adult medical-surgical intensive care unit to determine whether triple-lumen catheters reduce the need for peripheral vascular access and whether they are associated with a higher rate of infection than single-lumen catheters. PATIENTS AND METHODS After the insertion route, internal jugular or subclavian, was selected by the physician, patients were randomized either to single-lumen or triple-lumen catheter groups. Complementary peripheral vascular access was allowed in both groups. Catheters were removed according to preestablished defined reasons: suspicion of catheter-related sepsis, uselessness of central venous access, duration of catheterization of more than 21 days, discharge from the intensive care unit, or death. RESULTS Data on 129 central venous catheters were collected from 91 consecutive patients. Twenty-five of 68 patients from the single-lumen group and 1 of 61 patients from the triple-lumen group needed peripheral vascular access (p less than 0.001). Catheter-related sepsis rates, defined either by clinical signs and positive qualitative tip cultures (8.9% versus 11.5%) or by quantitative tip cultures (16.2% versus 11.5%), were identical in the single-lumen and triple-lumen groups (type II error: 8%). CONCLUSION In intensive care units, the use of triple-lumen catheters is associated with a dramatic decrease in the need for peripheral vascular access. The incidence of central venous catheter-related sepsis appears identical for single- and triple-lumen catheters.

High levels of portal TNF-α during abdominal aortic surgery in man

Abstract During shock or multiple organ dysfunction syndrome, translocation of bacteria and/or lipopolysaccharide (LPS) from the ischaemic gut might occur and could explain the excess of cytokine production detectable in plasma. To test this hypothesis, we studied a model of mild gut ischaemia due to bowel manipulation and aortic clamping in patients undergoing abdominal aortic surgery (n = 14). Per-operative levels of LPS and cytokines were measured before clamping and after reperfusion, and compared in systemic and portal blood. Systemic levels of LPS and cytokines were measured in a control group of patients undergoing internal carotid surgery (n = 7). Portal LPS was detectable (i.e., >12 pg/ml) in 36% of the patients undergoing aortic surgery after bowel manipulation, and in 71% after clamp release. Similar levels of LPS were observed in portal and systemic blood after clamp release. Circulating tumour necrosis factor alpha (TNF-α) was observed in all patients undergoing aortic surgery. Levels of portal TNF-α were higher than those in systemic blood after bowel manipulation as well as after reperfusion (P = 0.02 and 0.007, respectively). LPS was never detected in control patients and TNF-α was detectable in only two out of seven patients. Mean levels of IL-6 were similar in the two groups, with a peak on the day following surgery, confirming that circulating IL-6 is associated with any surgical procedures. Our data indicate that bowel manipulation, aortic clamping and reperfusion lead to similar levels of portal and systemic circulating LPS. High levels of portal TNF-α as compared to systemic ones, suggest that the gut-associated macrophages, activated by bowel manipulation, mild ischaemia, and/or translocated LPS, are a probable source of TNF-α.

Influence of surgery on in-vitro cytokine production by human monocytes.

Surgery leads to significant modulation of the immune system, in which cytokines play a major role. Circulating interleukin 6 (IL-6) and IL-1 have been reported following surgery whereas tumor necrosis factor alpha (TNF-alpha) is only found in gut ischemia-associated surgery. We have investigated the consequences of surgery on in-vitro cytokine production by human monocytes stimulated by lipopolysaccharide (LPS) and staphylococcal toxic shock syndrome toxin-1 (TSST-1). Comparisons were made between the responsiveness of cells obtained the day before (D-1), during (D0) and after (D1, D2, D3) surgery. Patients undergoing abdominal aortic surgery (N = 9), carotid surgery (N = 4) and spinal surgery (N = 4) have been studied. A significant decrease of TNF-alpha, IL-1 beta and IL-1 alpha production by monocytes prepared from blood samples taken during the surgery was noticed, whereas IL-6 production was not significantly modified. On D2 a significant increase of monocyte responsiveness was observed and levels of cytokine productions rose back to initial values by the end of the follow up. The diminished in-vitro cytokine production observed during surgery might be the consequence of the effects of anaesthetic drugs, whereas the enhancement observed on D2 might reflect the surgical stress, leading to in-vivo priming of circulating monocytes.

Acute Colorectal Ischemia after Aortic Surgery: Pathophysiology and Prognostic Criteria

Acute colorectal ischemia is a rare though potentially lethal complication of aortic surgery. We reviewed our recent experience with 16 cases in order to analyze its causative and prognostic factors. The incidence was 2.8%, and the inferior mesenteric artery was occluded in all cases. All patients also had severe occlusive disease of at least two of the hypogastric or deep femoral arteries. Hypoperfusion due to arterial ligation, prosthetic occlusion or embolism was responsible in half the cases. Ischemia and perfusion due to aortic cross-clamping or perioperative hemorrhage were involved in the rest of the cases. Postoperative mortality was 31%. The mortality was lower for partial, nontransmural necrosis, and for elective operations. Recurrent intestinal ischemia, transmural necrosis, surgery for ruptured aneurysm, intestinal hemorrhage and pulmonary edema were associated with a higher mortality rate. All patients with anuria or extrarenal epuration and hepatic cytolysis died. Although reconstruction of the inferior mesenteric artery might lessen the incidence of postoperative colonic ischemia due to hypoperfusion, the role of oxygen free radicals should be investigated in humans, in order to afford colonic protection against the consequences of ischemia-reperfusion.

Renal Revascularization in High-Risk Patients: The Role of Iliac Renal Bypass

Between 1984 and 1989, 29 iliac renal artery bypasses were performed in 29 patients (mean age 67.8 years) with severe renovascular disease due to atheroma. The indication for renal artery reconstruction was hypertension in all patients, which was associated with kidney failure in 16 cases. In six cases, reconstruction was performed after failure or complications of percutaneous transluminal angioplasty. The bypass was constructed with polytetrafluoroethylene in 24 cases (83%) and vein graft in five cases (17%). There was no postoperative mortality. All bypasses were found to be patent on duplex scanning or digital subtraction arteriograms. One patient was lost to follow-up. Mean follow-up was 23.2 months. One patient died of acute kidney failure, probably related to occlusion of the bypass. Hypertension improved in 22 cases (79%), was cured in two cases (7%), and remained unchanged in four (14%). Renal function remained unchanged in six cases (40%) and improved in nine (60%). Iliac-to-renal artery bypass seems to be the surgical renal revascularization modality best adapted to high-risk patients or those who have severe atheroma. Additionally, this technique enables rapid treatment of failures or complications of percutaneous transluminal angioplasty of the renal artery.

Effect of Subcutaneous Tunneling on Internal Jugular Catheter-Related Sepsis in Critically Ill Patients: A Prospective Randomized Multicenter Study

OBJECTIVE To evaluate the effect of catheter tunneling on internal jugular catheter-related sepsis in critically ill patients. DESIGN A prospective randomized controlled study involving 3 intensive care units (ICUs), stratified by number of catheter lumina (1 or 2) and center. SETTING The 10-bed medical-surgical and 10-bed surgical ICUs at Saint Joseph Hospital and 8-bed surgical ICU at Clinique de la Défense, Paris, France. PATIENTS Every patient older than 18 years admitted to the ICUs between March 1, 1993, and July 17,1996, who required a jugular venous catheter for more than 48 hours. INTERVENTION Random allocation to tunneled or nontunneled catheters. MEASUREMENTS Times to occurrence of systemic catheter-related sepsis, catheter-related septicemia, or a quantitative catheter-tip culture with a cutoff of 103 colony-forming units per milliliter. RESULTS A total of 241 patients were randomized. Ten patients in whom jugular puncture was not achieved were subsequently excluded. The proportion of patients receiving mechanical ventilation (87%) and mean+/-SD age (65+/-4 years), Simplified Acute Physiologic Score (13.3+/-4.9), Organ System Failure score (1.5+/-1.0), and duration of catheterization (8.7+/-5.0 days) were similar in both groups. Taking into account the first 231 catheters (114 nontunneled [control], 117 tunneled), we found that tunnelization decreased catheter-related sepsis (odds ratio [OR], 0.33; 95% confidence interval [CI], 0.13-0.83; P=.02), catheter-related septicemia (OR, 0.23; 95% CI, 0.07-0.81; P=.02), and, though not statistically significant, positive quantitative tip-culture rate (OR, 0.62; 95% CI, 0.35-1.10; P=.10). These results were slightly modified after adjustment on parameters either imbalanced between both groups (duration of catheter placement and cancer at admission) or prognostic (insertion by a resident, use of antibiotics at catheter insertion, cancer, and sex). CONCLUSION The incidence of internal jugular catheter-related infections in critically ill patients can be reduced by using subcutaneous tunnelization.