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Effect of acute nutritional restriction on incidence of anovulation and periovulatory estradiol and gonadotropin concentrations in beef heifers.

The effects of acute nutritional restriction on follicular dynamics, incidence of anovulation, and periovulatory estradiol and gonadotropin concentrations were studied in two replicates using beef heifers exhibiting regular estrous cycles. Heifers fed a diet supplying 1.2 maintenance (1.2 Mn) were synchronized using an intravaginal progesterone-releasing device for 8 days. One day before device removal, heifers were allocated randomly, within replicate, to a diet supplying 0.4 Mn (n = 20), or kept at 1.2 Mn (n = 21). On the sixth day after detected ovulation, heifers received 500 microg of synthetic prostaglandin F(2alpha) (PGF(2alpha)) to induce luteolysis, estrus, and ovulation of the first dominant follicle (DF). Animals were inseminated and returned to a diet of 1. 2 Mn. Pregnancy diagnosis was performed 30 days later. The maximum diameter subsequently attained by the DF present at progesterone withdrawal was smaller (P < 0.01) in heifers fed 0.4 Mn. Two heifers fed 0.4 Mn failed to ovulate this DF (P > 0.10). Growth rate (P < 0. 01) and maximum diameter (P < 0.001) of the DF in the first follicular wave of the next estrous cycle was also reduced in heifers fed 0.4 Mn. After prostaglandin administration, a further 10 heifers fed 0.4 Mn failed to ovulate the first DF of this cycle, and it regressed (P < 0.001), causing anovulation in 12 of 20 heifers within 13-15 days (P < 0.001). Anovulation of the DF present at progesterone withdrawal was preceded by a proestrous estradiol increase but absence of a gonadotropin surge (2 of 2 heifers), while neither endocrine event was detected before anovulation of the DF of the first new follicular wave (2 of 2 heifers). In cases in which ovulation of the first DF of the new cycle occurred, fertility was similar (P > 0.10) in heifers fed either 0.4 (n = 7) or 1.2 Mn (n = 20). In conclusion, acute nutritional restriction of cyclic heifers from 1.2 to 0.4 Mn decreased the growth rate and maximum diameter of DFs and induced failure of the DF to ovulate in 60% of heifers, but, within the confines of limited animal numbers, did not compromise fertility in heifers that ovulated.

Animal Nutritional Physiological Phenomena↗

New technologies in interventional cardiology.

This review confines itself to the new technologies that are widely used and that are being tested in formal trials. To date there have been few well-performed trials to compare the technologies, a fact that may have opened the way for the inappropriate use of some of these new technologies. This has allowed enthusiasts to perform procedures with as yet unproven tools no better and possibly worse than balloon angioplasty. New technologies can be broadly divided into three categories depending on their intended role: 1) mechanical removal, such as directional atherectomy, extractional atherectomy, and rotational atherectomy, that is designed to debulk lesions and remove atheromatous material, 2) high-energy removal by laser technologies designed to disobliterate lesions without producing the theoretically damaging lateral stretching of normal balloon angioplasty, 3) intraluminal scaffolding through the use of stents designed to give intravascular support, eg, balloon expandable, self-expanding, and temporary removable devices.

Angioplasty, Balloon, Coronary↗

Direct evidence of bacterial biofilms in otitis media.

OBJECTIVES/HYPOTHESIS: Bacteriologic studies of otitis media with effusion (OME) using highly sensitive techniques of molecular biology such as the polymerase chain reaction have demonstrated that traditional culturing methods are inadequate to detect many viable bacteria present in OME. The presence of pathogens attached to the middle-ear mucosa as a bacterial biofilm, rather than as free-floating organisms in a middle-ear effusion, has previously been suggested to explain these observations. The suggestion has been speculative, however, because no visual evidence of such biofilms on middle-ear mucosa has heretofore been collected. The hypotheses motivating the current study were: 1) biofilms of nontypable Hemophilus influenzae will form on the middle-ear mucosa of chinchillas in an experimental model of OME, 2) these biofilms will exhibit changes in density or structure over time, and 3) biofilms are also present on tympanostomy tubes in children with refractory post-tympanostomy otorrhea. The objective of this study was to collect visual evidence of the formation of bacterial biofilms in these situations. STUDY DESIGN: Laboratory study of bacteriology in an animal model and on medical devices removed from pediatric patients. METHODS: Experimental otitis media was induced in chinchillas by transbullar injection of nontypable H. influenzae. Animals were killed in a time series and the surface of the middle-ear mucosa was examined by scanning electron microscopy (SEM) for the presence of bacterial biofilms. Adult and fetal chinchilla uninfected controls were similarly examined for comparison. In addition, tympanostomy tubes that had been placed in children's ears to treat OME and removed after onset of refractory otorrhea or other problems were examined by SEM and by confocal scanning laser microscopy for bacterial biofilms, and compared with unused control tubes. RESULTS: Bacterial biofilms were visually detected by SEM on the middle-ear mucosa of multiple chinchillas in which H. influenzae otitis media had been induced. Qualitative evaluation indicated that the density and thickness of the biofilm might increase until at least 96 hours after injection. The appearance of the middle-ear mucosa of experimental animals contrasted with that of uninjected control animals. Robust bacterial biofilms were also visually detected on tympanostomy tubes removed from children's ears for clinical reasons, in contrast with unused control tubes. CONCLUSIONS: Bacterial biofilms form on the middle-ear mucosa of chinchillas in experimentally induced H. influenzae otitis media and can form on tympanostomy tubes placed in children's ears. Such biofilms can be directly observed by microscopy. These results reinforce the hypothesis that the bacterial aggregates called biofilms, resistant to treatment by antibiotics and to detection by standard culture techniques, may play a major etiologic role in OME and in one of its frequent complications, post-tympanostomy otorrhea.

Animals↗

Distraction osteogenesis for lengthening of the hard palate: Part I. A possible new treatment concept for velopharyngeal incompetence. Experimental study in dogs.

Many procedures have been described to correct velopharyngeal incompetence. Significant complications can occur, and the results may not be satisfactory. If the short soft palate has satisfactory muscle function and if it could be moved toward the posterior pharyngeal wall by distraction osteogenesis of the hard palate, an entirely new concept of treatment for velopharyngeal incompetence would be available. The object of the present study was to explore the possibility of osteogenesis occurring in the hard palate in dogs after gradual distraction (callus distraction). Six adult, mix-bred dogs were anesthetized, and the palatal mucosa was elevated. A midpalatal transverse osteotomy and two lateral osteotomies were performed. Tantalum bone markers for cephalometric analysis were placed, and an individually fabricated, orthodontic-like distraction device with an expansion screw in the sagittal direction was inserted. The device was stabilized on the premolars and fixed to the palatal bone with titanium miniscrews. Gradual distraction began after a latency period of 10 to 18 days. The rate of the distraction varied from 0.25 to 0.75 mm per day. The device was left in place for 6 to 8 weeks after expansion to allow for bony consolidation. Assessment was by direct examination, cephalograms, computed tomography, and histology with bone labeling. Impressions of the jaws were taken preoperatively and after device removal to examine plaster cast changes in the dental occlusion. Cephalometric and computed tomographic scan analysis demonstrated a distraction of up to 8 mm. All gaps were filled with de novo osteogenesis. Comparison of the plaster casts revealed no change in the occlusion. At 1 month after distraction, the computed tomographic scan showed the first signs of ossification of the experimental gap from the anterior and posterior bone ends. After 4.5 months ossification was almost complete with a small translucent zone in the middle of the experimental gap. After 7 months ossification was complete.

Animals↗

Adapting innovative motion-preserving technology to spinal surgical practice: what should we expect to happen?

STUDY DESIGN: A literature-based review of approach-related morbidity and a conjectural analysis of potential complications of disc arthroplasty based on experience with total joint arthroplasty. OBJECTIVE: To describe predictable complications of disc arthroplasty and possible strategies for minimizing or treating these complications. SUMMARY OF BACKGROUND DATA: There is a significant experience with anterior approach-related morbidity in spinal surgery. There is also extensive experience with extremity total joint arthroplasty. The combination of these experiences should predict certain occurrences that will occur with the advent of disc arthroplasty in the spine. METHODS: Review of the medical literature associated with anterior approach to the lumbar spine for spinal fusion was done. Sequential steps for performance of disc arthroplasty and possible problems with each step were evaluated and possible complications identified. Parallel experience in total joint arthroplasty was reviewed for possible predictive experience. RESULTS: There are definable approach-related morbidities that will occur, regardless of prosthesis design and implantation technique. Prosthesis design involves a series of tradeoffs for risks and benefits. Revisions are inevitable; rate of revision and time to revision remain to be determined. CONCLUSIONS: Disc arthroplasty will offer benefits over current fusion techniques. It will come at a cost and certain complications are entirely predictable. There will be deaths from the procedure, due to thromboembolic phenomenon or due to uncontrollable hemorrhage from irreparable vascular injury, especially on repeat operations. There will be prostheses that dislodge. There will be infections that require device removal, a very high-risk procedure. There will be a deterioration of results in the hands of the general medical community as opposed to the hands of the initial investigators, a learning curve if you will. The access surgeon will be critical to minimizing morbidity. Design considerations compete with anatomic constraints. Material choices all have pros and cons. Spine surgeons as a whole are excited about this opportunity, but we must be diligent to minimize these predictable adverse events to make the risk benefit profile the best that it can be for our patients.

Arthroplasty, Replacement↗

Antibiotic lock with vancomycin and urokinase can successfully treat colonized central venous catheters in pediatric cancer patients.

We used an antibiotic lock technique with vancomycin in combination with urokinase in 10 consecutive eligible children with Gram-positive catheter-related bacteremia persisting after appropriate intravenous antibiotics. Treatment was successful in sterilizing all colonized central venous catheters, avoiding device removal and delay of further chemotherapy. The antibiotic lock technique may represent a safe and effective therapeutic option in patients with selected, uncomplicated catheter-related bacteremias resistant to systemic antimicrobial therapy, particularly when maintaining a venous access is mandatory.

Adolescent↗

The Indiana experience with artificial urinary sphincters in children and young adults.

PURPOSE: We reviewed a 22-year single institutional experience with the artificial urinary sphincter in children and adolescents. To our knowledge this report represents the largest series in the world in children. MATERIALS AND METHODS: Between 1980 and 2002, 142 patients underwent implantation of an artificial urinary sphincter, of whom 93 males and 41 females with a median age of 10 years (range 3 to 39) were available for analysis. A total of 59 patients initially received an AMS 742/792 (American Medical Systems, Inc., Minnetonka, Minnesota) artificial urinary sphincter, of whom 33 were subsequently changed to an AMS 800, while 75 initially received an AMS 800 model. Sphincter followup was terminated at device removal or at the last documented contact. The etiology of incontinence was neuropathic bladder in 107 cases (80%), the exstrophy/epispadias complex in 21 (16%) and other in 6 (4%). Outcome measures included continence, mechanical complications (leakage, tube kink and pump malfunction), functioning sphincter revisions (change in cuff size, pump repositioning and bulbar cuff placement), surgical complications (erosion, infection and misplacement) and associated surgical procedures. Mean followup of the pre-800 and 800 models was 6.9 (range 0.2 to 21.5) and 7.5 years (range 0.1 to 17.1), respectively. Fisher's exact test, Kaplan-Meier life analysis and the chi-square test were used for statistical analysis. RESULTS: After artificial urinary sphincter placement in the 134 patients continence was achieved in 86%, improved in 4% and not achieved in 10%. Of those with a sphincter in place 92% were continent. In terms of bladder emptying after artificial urinary sphincter insertion 22% of patients voided, 11% voided combined with clean intermittent catheterization, 48% performed clean intermittent catheterization only via the urethra, 16% performed it via a catherizable channel and 3% used urinary diversion. A mechanical complication developed in 38 of the 59 patients (64%) with pre-800 model compared with 33 of the 109 (30%) with the 800 model (p <0.0001). A mechanical complication occurred every 7.6 versus 16 patient-years for the pre-800 versus 800 models (p = 0.0001). Revision was required in 15 of the 59 patients (25%) with a pre-800 model versus 17 of the 109 (16%) with the 800 model (p = 0.103). Revision was performed every 22.7 versus 44.3 patient-years for the pre-800 versus the 800 model (p = 0.023). The artificial urinary sphincter eroded in 11 of the 59 patients (19%) with the pre-800 versus 17 of the 109 (16%) with the 800 model (p = 0.52). Ten patients experienced a total of 12 perforations of the augmented bladder after artificial urinary sphincter implantation. A total of 164 secondary surgical procedures were performed, including 38 of 134 bladder augmentations (28%). A total of 30 sphincters were permanently removed. CONCLUSIONS: The artificial urinary sphincter is the only bladder neck procedure that allows spontaneous voiding in the neuropathic population, obviates the need for clean intermittent catheterization and yet is compatible with it when necessary. It is also equally versatile in the 2 genders. Mechanical complications occur but they were dramatically decreased by the modifications of the AMS 800 model. In addition, secondary bladder augmentation was required in 28% of our patients. Lifelong followup is mandatory in all patients with an artificial urinary sphincter.

Adolescent↗

Cranial vault distraction: its illusionary effect and limitation.

BACKGROUND: Distraction osteogenesis has some advantages, such as less hazardous complications, less scarring, and fewer bone defects. However, it has not been fully accepted yet because of a unidirectional expansion along the distraction device. Because cranial expansion is limited by scalp tension and soft-tissue scarring, undercorrection of the cranium and relapse of the vault deformities have occasionally been seen on long-term follow-up. These patients also had so much bone defect that the donor bone was inadequate for immediate revisions, and dissection under the scalp was complicated. METHODS: The authors used distraction osteogenesis to treat 12 cases of craniosynostosis. Five patients were syndromic (two cases of Pfeiffer's syndrome, two cases of Crouzon's disease, and one case of Apert's syndrome), and seven were nonsyndromic (four cases of brachycephaly, two cases of scaphocephaly, and one case of plagiocephaly). RESULTS: After only unidirectional expansion without vertical reduction, the shape of the cranium was satisfactorily improved, which might have been an illusion caused by the relative reduction attributed to the elongation by the distraction osteogenesis and, in brachycephaly, alteration of the patient's head position resulting from inclination of the facial plane by forehead advancement. However, in scaphocephaly, the unique deformity in the occipital and frontal regions remained after simple distraction. Distraction osteogenesis should be applied for a narrow cranium because the bone defect and scalp closure could pose problems. Radical reshaping should be used in cases of sufficient donor bone and scalp closure. Although additional surgery is unavoidable for device removal, minor revisions can be performed for revision of the irregularity at that time. CONCLUSION: Except for prolonged treatment, based on minimally invasive operations, distraction cranioplasty might be applied extensively in cases of craniosynostosis.

Acrocephalosyndactylia↗

Implant reconstruction in breast cancer patients treated with radiation therapy.

BACKGROUND: Implant reconstruction in breast cancer patients treated with radiation therapy is controversial. Prior studies are limited by older prosthetic devices, reconstructive techniques, and radiation therapy protocols. METHODS: A retrospective review was performed of patients who underwent tissue expansion and implant breast reconstruction performed by a single surgeon after mastectomy for breast cancer from 1996 to 2003. Complications and aesthetic results were compared between patients who received radiation therapy and those who did not. RESULTS: A total of 104 patients (123 breasts) who underwent mastectomy and implant breast reconstruction were included in the study. Twenty-seven patients (27 breasts) received either premastectomy or postmastectomy radiation therapy for breast cancer. All patients who received radiation therapy did so before completion of their implant reconstruction. Complications ultimately requiring prosthetic device removal or replacement, as well as total complications (those requiring prosthetic removal or replacement and those not requiring prosthetic removal or replacement), were more frequent in breasts that received radiation than breasts that did not (18.5 percent versus 4.2 percent for complications requiring prosthetic removal or replacement, p < or = 0.025, and 40.7 percent versus 16.7 percent for total complications, p < or = 0.01). Breast symmetry was significantly better in patients who did not receive radiation compared with those who did (p < 0.01). CONCLUSIONS: Implant breast reconstruction in patients who receive radiation therapy is possible but associated with more frequent complications and decreased aesthetic results. However, the present results compare favorably to those reported in prior studies. Improved results in the present study may be attributable to the use of newer prostheses, staged breast reconstruction with initial tissue expansion, total muscular coverage of the implant, and modern radiation therapy protocols.

Adult↗

Female sterilization in New South Wales, 1981 to 1994-1995.

This paper investigates and confirms the dramatic decline in female sterilization in New South Wales over the past decade, a period when male sterilization has remained fairly constant. The most significant decline occurred among women under 30 years of age, which resulted in a rise in the mean age at sterilization. In 1994-1995, 70% of sterilization operations were performed for contraceptive management only, 11% were concurrent with Caesarean section, and 9% with abortion. Incidental findings were an increase in Caesarean section and the proportion of women having concurrent sterilization, and a large decline in intrauterine device removals, more than half of which were accompanied with sterilization in 1994-1995. Currently-married women accounted for 80% of sterilization cases. Immigrant women generally had lower incidence of sterilization compared to the Australian-born.

Adult↗

Bradycardia and asystole with the use of vagus nerve stimulation for the treatment of epilepsy: a rare complication of intraoperative device testing.

PURPOSES: A 56-year-old man with mild mental retardation, right congenital hemiparesis, and refractory partial seizures was referred for vagus nerve stimulation (VNS). METHODS: Routine lead diagnostic testing during the surgical procedure (1.0 mA, 20 Hz, and 500 micros, for approximately 17 s) resulted, during the initial two stimulations, in a bradycardia of approximately 30 beats/min. A third attempt led to transient asystole that required atropine and brief cardiopulmonary resuscitation. RESULTS: The procedure was immediately terminated, the device removed, and the patient recovered completely. A postoperative cardiologic evaluation, including an ECG, 24-h Holter monitor, echocardiogram, and a tilt-table test, was normal. CONCLUSIONS: Possible mechanisms for the bradycardia/asystole include stimulation of cervical cardiac branches of the vagus nerve either by collateral current spread or directly by inadvertent placement of the electrodes on one of these branches; improper plugging of the electrodes into the pulse generator, resulting in erratic varying intensity of stimulation; reverse polarity; and idiosyncratic-type reaction in a hypersusceptible individual. The manufacturer reports the occurrence rate in approximately 3,500 implants for this intraoperative event to be approximately one in 875 cases or 0.1%.

Bradycardia↗

Complications of implantable cardioverter defibrillator therapy in 440 consecutive patients.

BACKGROUND: Although more than 150,000 implantable cardioverter defibrillators (ICDs) are implanted yearly worldwide, only few studies systematically examined complications of ICD therapy in large patient cohorts. METHODS: We prospectively analyzed ICD-related complications in 440 consecutive patients who underwent first implantation of an ICD system for primary or secondary prevention of sudden cardiac death within the last 10 years at our institution. All study patients received pectoral nonthoracotomy ICD lead systems with the exception of one patient who had an artificial tricuspid valve. RESULTS: During 46 +/- 37 months follow-up, 136 of 440 patients (31%) experienced at least one complication including implant procedure-related complications in 43 patients (10%), ICD generator-related complications in 28 patients (6%), lead-related complications in 52 patients (12%), and inappropriate shocks in 54 patients (12%). The most serious complications included one perioperative death due to heart failure (0.2%), two ICD system infections necessitating device removal (0.5%) and two perioperative cerebrovascular strokes (0.5%). CONCLUSIONS: We conclude that more than one quarter of ICD patients experience complications during a mean follow-up of almost 4 years, although serious complications such as intraoperative death or ICD system infections are rare in patients with nonthoracotomy ICD systems. Recognition of these complications is the prerequisite for advances in ICD technology and management strategies to avoid their recurrence.

Death, Sudden, Cardiac↗

Effect of reduced scatter on radiographic information content and patient exposure: a quantitative demonstration.

If a normal screen-film exposure is made using a conventional grid, a reduced exposure may be used with a superior scatter removal device to record the same image information. This theoretical conclusion is not readily demonstrated because of the limited visibility on the underexposed film. In this study radiographs underexposed by a factor of three with a scanning multiple slit assembly (SMSA) were enhanced autoradiographically and found visually to contain more information than properly exposed radiographs obtained under similar conditions using a conventional Bucky grid. This observation was confirmed by contrast scale and noise measurements. Furthermore, the entrance skin exposure of the radiograph using the SMSA was 45% of that required with the grid technique at the same beam quality.

Radiation Dosage↗

Putative role of beta-1,3 glucans in Candida albicans biofilm resistance.

Biofilms are microbial communities, embedded in a polymeric matrix, growing attached to a surface. Nearly all device-associated infections involve growth in the biofilm life style. Biofilm communities have characteristic architecture and distinct phenotypic properties. The most clinically important phenotype involves extraordinary resistance to antimicrobial therapy, making biofilm infections very difficulty to cure without device removal. The current studies examine drug resistance in Candida albicans biofilms. Similar to previous reports, we observed marked fluconazole and amphotericin B resistance in a C. albicans biofilm both in vitro and in vivo. We identified biofilm-associated cell wall architectural changes and increased beta-1,3 glucan content in C. albicans cell walls from a biofilm compared to planktonic organisms. Elevated beta-1,3 glucan levels were also found in the surrounding biofilm milieu and as part of the matrix both from in vitro and in vivo biofilm models. We thus investigated the possible contribution of beta-glucans to antimicrobial resistance in Candida albicans biofilms. Initial studies examined the ability of cell wall and cell supernatant from biofilm and planktonic C. albicans to bind fluconazole. The cell walls from both environmental conditions bound fluconazole; however, four- to fivefold more compound was bound to the biofilm cell walls. Culture supernatant from the biofilm, but not planktonic cells, bound a measurable amount of this antifungal agent. We next investigated the effect of enzymatic modification of beta-1,3 glucans on biofilm cell viability and the susceptibility of biofilm cells to fluconazole and amphotericin B. We observed a dose-dependent killing of in vitro biofilm cells in the presence of three different beta-glucanase preparations. These same concentrations had no impact on planktonic cell viability. beta-1,3 Glucanase markedly enhanced the activity of both fluconazole and amphotericin B. These observations were corroborated with an in vivo biofilm model. Exogenous biofilm matrix and commercial beta-1,3 glucan reduced the activity of fluconazole against planktonic C. albicans in vitro. In sum, the current investigation identified glucan changes associated with C. albicans biofilm cells, demonstrated preferential binding of these biofilm cell components to antifungals, and showed a positive impact of the modification of biofilm beta-1,3 glucans on drug susceptibility. These results provide indirect evidence suggesting a role for glucans in biofilm resistance and present a strong rationale for further molecular dissection of this resistance mechanism to identify new drug targets to treat biofilm infections.

Amphotericin B↗

Microbiological evaluation of the vacuum probe surface sampler.

The development of the vacuum probe, a new device for surface sampling, was recently reported. The original technique was slightly modified and a microbiological evaluation was conducted. The probe proved to be an effective sampling device, removing 98% and recovering 88% of surface contaminants resulting from the accumulation of airborne microorganisms. The probe was decidedly less effective in removing and recovering handling contamination than fallout contamination. There was also evidence that certain microorganisms could not survive prolonged exposure to airflow in the probe. However, the vacuum probe procedure recovered twice as many microorganisms as did the swab-rinse technique when compared directly.

Air Microbiology↗

Antibacterial activity in blood cultures.

A total of 2,010 blood samples inoculated into tryptic soy broth were examined for antibacterial activity by means of a bioassay plate seeded with Bacillus subtilis spores. The size of the zone of inhibition on this plate was indicative of the degree of antibacterial activity. Current antibiotic therapy was confirmed by examination of chart records. Of the 2,010 blood cultures tested, 147 (7.3%) contained detectable levels of antibiotics; of these 147, 14 (9.5%) yielded growth of bacteria, and 133 (90.5%) remained negative. When the Antibiotic Removal Device (Marion Scientific, Div. Marion Laboratories, Inc., Kansas City, Mo.) was used, it eliminated the antibacterial activity but did not improve the recovery of bacteria from these cultures. Only bacteria resistant to the respective antibiotic were recovered from blood cultures that showed high levels of antibacterial activity (beta-lactam antibiotics, greater than 0.60 micrograms/ml; aminoglycosides, greater than 2 micrograms/ml; and tetracycline, greater than 4 micrograms/ml). Blood cultures showing low levels of antibacterial activity yielded both resistant and susceptible bacteria.

Anti-Bacterial Agents↗

Comparison of BACTEC 9240 and BacT/Alert blood culture systems in an adult hospital.

In a study comparing the BACTEC 9240 (Becton Dickinson, Canada Inc., Mississauga, Ontario, Canada) and the BacT/Alert (Organon Teknika, Scarborough, Ontario, Canada) blood culture systems, 6,437 sets of four bottles of 10,412 cultures submitted were deemed acceptable for evaluation. There were 586 clinically significant isolates from 544 positive blood cultures. Of the 544 positive blood cultures, 329 were positive in both systems, 157 were positive in the BACTEC 9240 system alone, and 58 were positive in the BacT/Alert system alone (P < 0.001). These cultures represented 421 bacteremic episodes, of which 290 were detected by both systems, 84 were detected by the BACTEC 9240 system alone, and 47 were detected by the BacT/Alert system alone (P < 0.001). The difference between the two systems in terms of microbial recovery was attributable largely to differences in the ability to grow staphylococci. Of 82 monomicrobial isolates of Staphylococcus aureus, 46 were isolated by both systems, 30 were isolated by the BACTEC 9240 system alone, and 6 were isolated by the BacT/Alert system alone (P < 0.0001). A similar pattern was noted in the case of coagulase-negative staphylococci, of which 48 were isolated in both systems, 46 were isolated in the BACTEC 9240 system alone, and 5 were isolated in the BacT/Alert system alone (P < 0.0001). The false-positive rate in the BACTEC 9240 system was 0.5%, and that in the BacT/Alert system was 1.2%. Both systems provided satisfactory service mechanically, and in terms of computer software and costs, both systems were similar. The differences in the recovery of organisms, notably staphylococci, may be due in part to the fact that in the present study the BacT/Alert medium did not contain antimicrobial agent-removing devices, whereas the BACTEC 9240 medium did. Until this difference is resolved, we consider the BACTEC 9240 system to more adequately meet our hospital's requirements.

Adult↗

Morbidity using subcutaneous ports and efficacy of vancomycin flushing in cancer.

An evaluation of totally implanted venous access systems inserted in 163 consecutive children with cancer is reported. From 1988 to 1994, 180 subcutaneous ports were inserted in children more than 1 year old. Initial diagnosis was acute leukaemia (n = 79), non-Hodgkin's lymphoma (n = 33), and solid tumour (n = 51). Median age was 85 months. All venous procedures were performed through the device. Chemotherapy was either moderate (n = 13) or intensive (n = 119) or very intensive (n = 48), including 16 patients undergoing marrow transplantation. Cumulative venous access totalled 55,770 patient days with a mean of 305 days/subcutaneous port. The cause of device removal was, end of treatment (n = 111), death due to malignancy (n = 20), catheter related infection (n = 7), and occlusion of the system (n = 4). Mechanical complications occurred in 19 ports; 16 were due to clots, of which 14 were cleared with instillation of urokinase. Documented infectious episodes occurred in 47 ports, recurred once in 14, and twice in five cases. Among these infections, 47 were septicaemic; 31 due to Staphylococcus epidermidis. Twenty seven of initial septic episodes were considered to be catheter related; the rate was 15%/subcutaneous port or 0.05/100 catheter days. Risk factors for the development of a first infection were age below 4 years and the time of use. Since February 1993, vancomycin (50 micrograms/ml) has been given and this has reduced the rate of S epidermidis infection from 26/83 subcutaneous port to 4/97. Life table analysis showed that the infection free interval for staphylococcus was significantly better after this technique ws initiated (log rank rest=0.02). Time saved was approximately 30minutes/patient/week compared with external catheters, or 45 hours/month for the cohort of children treated. Subcutaneous ports in paediatric cancer patients are reliable, safe, and durable and may offer an attractive alternative to external catheters for prolonged venous access and intensive treatment.

Adolescent↗