Ethanol lock and risk of hemodialysis catheter infection in critically ill patients. A randomized controlled trial.

RATIONALE: Ethanol rapidly eradicated experimental biofilm. Clinical studies of ethanol lock to prevent catheter-related infections (CRIs) suggest preventive efficacy. No such studies have been done in intensive care units (ICU). OBJECTIVES: To determine whether ethanol lock decreases the risk of major CRI in patients with short-term dialysis catheters (DCs). METHODS: A randomized, double-blind, placebo-controlled trial was performed in 16 ICUs in seven university hospitals and one general hospital in France between June 2009 and December 2011. Adults with insertion of a nontunneled, nonantimicrobial-impregnated double-lumen DC for an expected duration greater than 48 hours, to perform renal-replacement therapy or plasma exchange, were randomly allocated (1:1) to receive a 2-minute catheter lock with either 60% wt/wt ethanol solution (ethanol group) or 0.9% saline solution (control group) at the end of DC insertion and after each renal-replacement therapy or plasma exchange session. The main outcome was major CRI defined as either catheter-related clinical sepsis without bloodstream infection or catheter-related bloodstream infection during the ICU stay. MEASUREMENTS AND MAIN RESULTS: The intent-to-treat analysis included 1,460 patients (2,172 catheters, 12,944 catheter-days, and 8,442 study locks). Median DC duration was 4 days (interquartile range, 2-8) and was similar in both groups. Major CRI incidence did not differ between the ethanol and control groups (3.83 vs. 2.64 per 1,000 catheter-days, respectively; hazard ratio, 1.55; 95% confidence interval, 0.83-2.87; P = 0.17). No significant differences occurred for catheter colonization (P = 0.57) or catheter-related bloodstream infection (P = 0.99). CONCLUSIONS: A 2-minute ethanol lock does not decrease the frequency of infection of DCs in ICU patients. Clinical trial registered with www.clinicaltrials.gov (NCT 00875069).

Protective mechanisms in hypobaric decompression.

BACKGROUND: To reduce bubble formation and growth during hypobaric exposures, a denitrogenation or nitrogen "washout" procedure is performed. This procedure consists of prebreathing oxygen fractions as close to one as possible (oxygen prebreathe) prior to depressurization before ascending to the working altitude or low spacesuit pressures. During the NASA prebreathe reduction program (PRP), it was determined that the addition of a light arm exercise to short, individually designed, performance-based heavy exercise (dual cycle ergometry) during an abbreviated 2-h prebreathe (F1O2 - 1.0) reduced the occurrence of decompression sickness (DCS). Heavy-exercise-induced DCS reduction is likely to be related to the enhancement of the tissue nitrogen washout during the oxygen prebreathe. In addition to the heavy-exercise-induced microcirculatory adaptation, we hypothesized that the light exercise would not cause sufficient microcirculatory changes in the limbs to explain alone this further DCS protection. We evaluated microcirculatory changes as minimal by replicating the exercise characteristics of the PRP trials in 13 healthy subjects. METHODS: Noninvasive near infrared spectroscopy (NIRS) allowed observation of instantaneous variations of total, oxygenated, and deoxygenated hemoglobin/myoglobin concentrations in the microcirculatory networks (probes facing the vastus lateralis and deltoid muscles) of active limbs during dynamic exercise. RESULTS: The high-intensity leg exercise alone produced the changes in NIRS parameters; the light arm exercise induced minimal microcirculatory volume changes. However, this coupling appeared to be critical in previous altitude PRP chamber studies by reducing DCS. DISCUSSION: With only minimal microcirculatory blood volume changes, it is unlikely that light exercise alone causes significant nitrogen tissue washout. Therefore, our results suggest that in addition to nitrogen tissue washout, another unknown exercise-induced effect may have further enhanced the DCS protection, possibly mediated via the anti-inflammatory effect of exercise, gas micronuclei reduction, NO pathways, or other molecular mechanisms.

Rotational Atherectomy Versus Intravascular Lithotripsy for Calcified In-Stent Restenosis: A Single-Center Study With 1-Year Follow-Up.

Although rotational atherectomy (RA) and intravascular lithotripsy (IVL) have been proved to be effective for calcified de novo coronary lesions, their use in patients with in-stent restenosis (ISR) is still controversial. No comparison of these techniques in patients with ISR has been published so far. We sought to evaluate safety and feasibility of RA and IVL in patients with calcified ISR. Furthermore, we aimed to compare in-hospital and 1-year clinical outcomes between both groups. This is a retrospective single-center study evaluating patients with calcified ISR treated with RA (between 2012 and 2021) and IVL (between 2019 and 2021). Inhospital and 1-year clinical outcomes were compared between IVL and RA patients. In total, 28 patients with ISR who underwent RA were compared with 24 ISR subjects after IVL. The procedural success rate was 100% in both the groups. Quantitative coronary analysis demonstrated a similar degree of stenosis prior (66.4 ± 11.4 vs 68.8 ± 19.7, p = nonsignificant [NS]), and after the procedure (21.5 ± 20.5 vs 22.8 ± 12.1, p = NS) with no difference in acute luminal gain (1.34 ± 0.60 vs 1.38 ± 0.59, p = NS). There was one in-hospital major adverse cardiovascular event in the RA group. At 1-year follow-up, no difference was observed with respect to major adverse cardiovascular event rate (14.3% vs 16.7%, p = NS) and target vessel revascularization (7.1% vs 12.5%, p = NS). In conclusion, RA and IVL are safe and feasible techniques for calcified ISR yielding comparable results at 1-year follow-up. Further clinical studies are warranted to confirm our findings and shed more light on patient and lesion characteristics associated with the best outcomes.

Energy expenditure, spontaneous physical activity and with weight gain in kidney transplant recipients.

BACKGROUND & AIMS: Alterations in energy metabolism could trigger weight gain after renal transplantation. METHODS: Nineteen transplanted non-diabetic men, 53 ± 1.6 years old, receiving calcineurin inhibitors but no corticosteroids were studied. They were compared with nine healthy men matched for height, age and lean body mass. Daily energy expenditure and its components (sleeping, basal and absorptive metabolic rates) were analyzed for 24 h in calorimetric chambers and for 4 days in free living conditions using calibrated accelerometry. Other variables known to influence energy expenditure were assessed: body composition, physical activity, 4-day food intake, drug consumption, serum C-reactive protein, interleukin-6, thyroid and parathyroid hormones, and epinephrine. Transplant recipients who gained more than 5% body weight after transplantation (n = 11, +11.0 ± 1.5 kg) were compared with those who did not (n = 8) and with the controls. RESULTS: Weight gain compared with non-weight gain patients and controls exhibited higher fat mass without change in lean body mass. Daily, sleeping and resting energy expenditure adjusted for lean body mass was significantly higher in non-weight gain (167.1 ± 4.2 kJ/kg/lean body mass/24 h, P < 0.05) compared with weight gain patients (147.4 ± 3.6) and controls (146.1 ± 4.6). Weight gain compared with controls and non-weight gain subjects had lower free living physical activity and a higher consumption of antihypertensive drugs and ß-blockers. CONCLUSIONS: After kidney transplantation, weight gain patients were characterized by lower adjusted energy expenditure, reduced spontaneous physical activity but a more sedentary life style and a trend toward a higher energy intake explaining the reason they gained weight. The nWG KTR had increased resting and sleeping EE which protected them from weight gain. Such hypermetabolism was also observed in 24-h EE measurements. By comparison with the nWG patients, the WG transplant recipients were characterized by higher ß-blocker consumption. These data could be helpful in the prevention of weight gain in kidney transplant recipients.

Pulmonary arterial systolic pressure and susceptibility to high altitude pulmonary edema.

There is evidence that pulmonary arterial hypertension plays a major role in the occurrence of high altitude pulmonary edema (HAPE). We tested the hypothesis that the pulmonary arterial systolic pressure response to a challenge associated with hypoxia and mild exercise may be considered a predictive factor of HAPE. Pulmonary arterial systolic pressure was measured by Doppler echocardiography in 8 HAPE susceptible (HAPE-S) subjects and 8 HAPE resistant mountaineers (HAPE-R) during a hypoxic exercise challenge established by the French Association for Sport Medicine (Richalet's test). Pulmonary arterial systolic pressure during hypoxic exercise allowed a significant discrimination between the groups, although an overlap of values was observed. When expressed as individual variations from baseline to hypoxic exercise level however, we found a highly significant difference. No overlap was observed between HAPE-R (range: 6.7-18.5 mmHg) and HAPE-S (range: 19.2-30.4 mmHg) groups, with a cut-off value at 19 mmHg. Plasma Vascular Endothelial growth factor (VEGF) and malondialdehyde (MDA) increased in response to hypoxic exercise only in HAPE-S group. Individual increases in pulmonary arterial systolic pressure during hypoxic exercise from basal resting normoxic values seem relevant to estimate HAPE susceptibility when measured during the Richalet's test.

Organizing pneumonia after rituximab therapy: Two cases.

Rituximab, a chimeric monoclonal antibody against CD20, very rarely causes lung toxicity. Clinical presentations include lung infiltrates, alveolar hemorrhage, and adult respiratory distress syndrome. Three cases of organizing pneumoinia (formerly called bronchiolitis obliterans with organizing pneumonia or BOOP) have been reported. In our experience, organizing pneumonia occurred in 2 of 25 patients treated with rituximab, for RA and Castleman's disease, respectively. Because organizing pneumonia may be asymptomatic, as illustrated by one of our cases, we recommend obtaining a chest radiograph routinely before rituximab re-treatment.