Fungal prosthetic valve endocarditis in 16 patients. An 11-year experience in a tertiary care hospital.

Fungal prosthetic valve endocarditis (PVE) is an infrequent but serious complication of valve replacement surgery. To examine its long-term outcome, we retrospectively studied 16 patients with 19 episodes of definite fungal PVE. The mean age was 51 years (range, 27-71 yr). Onset of fungal PVE ranged from 8 days to 3.4 years after valve replacement. Candida albicans was the most common (56%) pathogen isolated. A portal of entry was identified in only 25% of the patients; the presence of intravascular catheters (50%) and prior bacterial endocarditis (38%) were leading predisposing factors. Fever (83%) was the most consistent clinical finding. Potentially serious embolic events, particularly strokes (32%), were common at presentation. Transesophageal echocardiography (sensitivity = 100%) was more useful than transthoracic echocardiography (sensitivity = 60%) in detecting lesions due to fungal PVE. Combined valve replacement surgery and amphotericin B (mean total dose of 1.8 g) in 15 patients resulted in an 87% in-hospital survival and 67% overall survival with a mean follow-up of 4.5 years (range, 5 mo to 16 yr). Two patients had 3 late relapses of fungal PVE up to 9 years after the preceding episode. Each relapse was treated with repeat valve replacement and amphotericin B; in addition, oral azole was utilized for chronic suppression, although the efficacy of this strategy remains unproven. Because of the possibility of relapse, long-term follow-up is essential even after surgical and prolonged antifungal therapy.

Incidence and risk of developing fungal prosthetic valve endocarditis after nosocomial candidemia.

PURPOSE: To determine the incidence of prosthetic valve endocarditis (PVE) in fungemic patients with prosthetic heart valves (PHV), estimate risk of subsequent PVE, and describe risk factors and diagnostic and therapeutic management issues in such patients. PATIENTS AND METHODS: This is a retrospective chart review in a 1,100-bed tertiary referral center with an active cardiothoracic surgical service. Forty-four patients with PHVs developed nosocomial fungemia between January 1985 and April 1995. RESULTS: Of 44 patients, 33 never developed evidence of PVE (group 1), 7 (16%) had evidence of PVE at the time of candidemia (group 2), and 4 (9%) developed PVE a mean of 232 days after candidemia (group 3). Predisposing factors including intravascular lines, prior antibiotic therapy, and an identifiable portal of entry for fungemia were common in group 1 but not group 2. Candidemia occurred significantly later after PHV surgery in group 2 (mean 270 days) as compared to groups 1 and 3 (means 48 and 15.5 days, respectively; P = 0.02). Ten of 11 patients with Candida PVE (group 2 and 3) were treated with amphotericin B and valve replacement. Three relapses after combined therapy were documented in two patients. Mortality was significantly higher for patients without Candida PVE (group 1) as compared to patients with Candida PVE (groups 2 and 3) at 1 month (53% vs 9%), 2 months (69% vs 20%) and 1 year (83% vs 25%) after candidemia. CONCLUSIONS: Patients with prosthetic heart valves who develop nosocomial candidemia are at notable risk of either having or developing Candida PVE months or years later. Late onset candidemia and lack of an identifiable portal of entry should heighten concern about Candida PVE in such patients.

Protective effect of 21-aminosteroid pretreatment in peripheral nerve low-load crush injury in mature and immature rats.

The effects of U-74006F (tirilazad mesylate), a 21-aminosteroid antioxidant, on injured peripheral nerve were studied. Twenty-two immature and 44 mature rats were divided equally into two groups. The experimental group received two injections of 3 mg/kg of U-74006F at a 2 hour interval. The control group received the same volumes of a citrate buffer. A 5 mm segment of the sciatic nerve was subjected to a crush load of 100 g for 2 hours. Motor function (sciatic functional index) was assessed to day 48 postoperatively. There was total paralysis of the crushed limb in all rats the first week after crushing. The experimental group had a statistically significant improvement in motor function compared with the controls on days 14, 21, 25, and 28 for the mature rats and on days 11 and 14 for the immature rats. The mature controls attained complete recovery on day 42 and had a significantly slower recovery rate than the immature controls, which had recovered fully by day 25. The recovery rates were almost similar among mature and immature groups pretreated with U-74006F, both of which had fully recovered motor function by day 28. The results indicate that pretreatment with U-74006F can significantly promote peripheral nerve function after low-load crush injury and that the age of the animal influences the rate of peripheral nerve recovery.

Effects of S-nitroso-N-acetylcysteine on contractile function of reperfused skeletal muscle.

The ultimate goal of replantation and microsurgical reconstructive operations is to regain or improve impaired function of the tissue. However, the data related to the influence of NO on tissue function are limited. This study evaluated the effects of the NO donor S-nitroso-N-acetylcysteine (SNAC) on contractile function of skeletal muscle during reperfusion. Forty-nine rats were divided into six groups. The extensor digitorum longus (EDL) muscles in groups I and II were not subjected to ischemia-reperfusion but were treated with a low (100 nmol/min) or high (1 mumol/min) dose of SNAC. In groups III-V, the EDL underwent 3 h of ischemia and 3 h of reperfusion and was also treated with low (100 nmol/min) or high doses (1 or 5 mumol/min) of SNAC. Group VI was a phosphate-buffered saline (PBS)-treated control group. Twenty additional animals were used to document systemic effects of SNAC and PBS only. SNAC or PBS was infused for 6.5 h, beginning 30 min before ischemia and continuing throughout the duration of reperfusion. Contractile testing compared the maximal twitch force, isometric tetanic contractile forces, fatigue, and fatigue half time of the experimental EDL and the contralateral nontreated EDL. The findings indicate that 1) SNAC does not influence contractile function of EDL muscle not subjected to ischemia-reperfusion, 2) SNAC significantly protects the contractile function of ischemic skeletal muscle against reperfusion injury in the early reperfusion period, and 3) the protective role of SNAC is critically dosage dependent; protection is lost at higher doses. The conclusion from this study is that supplementation with exogenous NO exerts a protective effect on the tissue against reperfusion injury.

Routine cultures of bone marrow and peripheral stem cell harvests: clinical impact, cost analysis, and review.

The American Association of Blood Banks requires routine culture of hematopoietic progenitor cells prior to bone marrow transplantation. We sought to evaluate the cost of that requirement and the incidence and clinical significance of positive cultures. We performed a retrospective analysis of transplant recipients at our institution. Of the 605 patients for whom 1,934 consecutive cultures of harvests were done between December 1992 and February 1996, 11 had positive cultures. Six patients received a culture-positive harvest with no adverse effects. The total cost of cultures was $35,660 (U.S. $). In North America and worldwide in 1995, routine culture of harvests would have prevented 7.9 and 18.9 cases of bacteremia, respectively, at a cost of $95,000 per bacteremia prevented. We conclude that routine culture of hematopoietic progenitor cells yields low rates of positivity and that infusion of contaminated harvests rarely results in clinically adverse outcomes.