Remnant-Sparing Anterior Cruciate Ligament Reconstruction Results in Similar Clinical, Functional, and Quality-of-Life Outcomes to Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction.

Purpose: To compare a large cohort of patients who underwent remnant-sparing anterior cruciate ligament reconstruction (rACLR) with a matched group of patients who underwent anatomic single-bundle anterior cruciate ligament reconstruction (ACLR) with respect to clinical laxity, patient-reported outcomes, and functional testing. Methods: Patients who underwent rACLR between January 2010 and December 2015 were matched according to age, sex, body mass index, and graft type to patients who underwent ACLR. The primary outcome measure was the ACL Quality of Life (ACL-QOL) score at final follow-up of 24 months. Secondary outcomes included functional tests and clinical laxity measurements at 6, 12, and 24 months postoperatively. Concurrent intra-articular pathology at the time of surgery and postoperative complications were also recorded. Statistical analyses included the dependent t test and the Wilcoxon signed rank test. Results: A total of 210 rACLR patients were successfully matched to a corresponding cohort of 210 ACLR patients. There were no statistically significant differences in ACL Quality of Life (ACL-QOL) or functional testing results between the groups; however, scores in both groups showed a steady and statistically significant improvement over time. A statistically significant difference was noted with respect to the Lachman test findings, favoring the rACLR cohort (Z = -2.79, P = .005); no between-group difference was seen for the pivot-shift test (Z = -0.36, P = .72). The rACLR group had a significantly lower rate of concurrent meniscal and chondral injury. There was no difference in complications between the groups (Z = -0.49, P = .63). Conclusions: There was no difference in patient-reported or functional testing outcomes in patients undergoing remnant-sparing compared with anatomic single-bundle ACLR. There was, however, a significantly lower rate of positive Lachman test findings after rACLR. Furthermore, the rate of concurrent meniscal and chondral pathology was lower in the rACLR group. Level of Evidence: Level III, retrospective cohort study.

Evolution of a Novel Tissue Preservation Protocol to Optimize Osteochondral Transplantation Outcomes.

OBJECTIVE: Osteochondral allograft transplantation is a procedure to treat focal osteochondral lesions (OCLs), but is limited by tissue availability, the quality of transplanted tissue, and inconsistent storage protocols. The objective of this study was to assess the clinical outcomes of a novel tissue procurement, storage, and quality control protocol in treating OCLs. DESIGN: Prospective case series. Donor cadaveric tissue was processed, stored, and the tissue quality analyzed using the unique tissue preservation protocol developed at our institution. Advanced cross-sectional imaging was used to size match donor tissue with recipient patients. Osteochondral allografts were transplanted using the Arthrex Allograft OATS. Patients were evaluated with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee injury and Osteoarthritis Outcome Score (KOOS), visual analog scale (VAS), and 36-Item Short Form Survey (SF-36) preoperatively and at 1 year and 2 years postoperatively. RESULTS: Twenty patients (17 knees, 3 shoulders) were included in the study. There was a significant improvement in the following scores: overall WOMAC score, WOMAC function and pain subcategories; KOOS pain, knee-related symptoms, activities of daily living, sports and recreation, and quality of life; SF-36 physical functioning, physical role, pain, and social functioning subcategories; and VAS at all time points postoperatively. There was a significant improvement in WOMAC stiffness at 2 years postoperatively. There were 2 failures, defined by graft subsidence and persistent pain requiring reoperation. CONCLUSION: The protocol developed at our institution for OAT resulted in significant clinical improvement in patients with OCLs and is an improvement on existing tissue storage techniques.

Prospective study evaluating the relative sensitivity of 18F-NaF PET/CT for detecting skeletal metastases from renal cell carcinoma in comparison to multidetector CT and 99mTc-MDP bone scintigraphy, using an adaptive trial design.

BACKGROUND: The detection of occult bone metastases is a key factor in determining the management of patients with renal cell carcinoma (RCC), especially when curative surgery is considered. This prospective study assessed the sensitivity of (18)F-labelled sodium fluoride in conjunction with positron emission tomography/computed tomography ((18)F-NaF PET/CT) for detecting RCC bone metastases, compared with conventional imaging by bone scintigraphy or CT. PATIENTS AND METHODS: An adaptive two-stage trial design was utilized, which was stopped after the first stage due to statistical efficacy. Ten patients with stage IV RCC and bone metastases were imaged with (18)F-NaF PET/CT and (99m)Tc-labelled methylene diphosphonate ((99m)Tc-MDP) bone scintigraphy including pelvic single photon emission computed tomography (SPECT). Images were reported independently by experienced radiologists and nuclear medicine physicians using a 5-point scoring system. RESULTS: Seventy-seven lesions were diagnosed as malignant: 100% were identified by (18)F-NaF PET/CT, 46% by CT and 29% by bone scintigraphy/SPECT. Standard-of-care imaging with CT and bone scintigraphy identified 65% of the metastases reported by (18)F-NaF PET/CT. On an individual patient basis, (18)F-NaF PET/CT detected more RCC metastases than (99m)Tc-MDP bone scintigraphy/SPECT or CT alone (P = 0.007). The metabolic volumes, mean and maximum standardized uptake values (SUV mean and SUV max) of the malignant lesions were significantly greater than those of the benign lesions (P < 0.001). CONCLUSIONS: (18)F-NaF PET/CT is significantly more sensitive at detecting RCC skeletal metastases than conventional bone scintigraphy or CT. The detection of occult bone metastases could greatly alter patient management, particularly in the context when standard-of-care imaging is negative for skeletal metastases.

Effects of an in-house coordinator and practitioner referral rather than proxy referral on tissue donation rates.

INTRODUCTION: Timely referral of patients following asystolic death to an organ procurement organization (OPO) may increase tissue donation rates. Lack of education of health care providers and nonphysicians (admitting department) about timely referral to the OPO following asystolic death may adversely affect tissue donation rates. We hypothesized that using an in-house donation coordinator for provider education and changing the responsibility for calling the OPO from the admitting department to the licensed independent practitioner (LIP) declaring death would increase timely referral and tissue donation rates. METHODS: An education program was developed in 2005 by a newly hired in-house coordinator to highlight the importance of tissue donation. In addition, to improve timely referrals to the OPO after death, the instructions accompanying the working copy of the death certificate were altered to require the patient's LIP to call the OPO within 1 hour of death (early 2007). Rates for both timely referrals and tissue donors were modeled by a Poisson regression model with a log link function. RESULTS: Timely referral rates rose from 48% before the interventions to 72% after the intervention (P < .0001). The number of tissue donors per number of referrals also increased significantly (P = .025) over that period. CONCLUSIONS: An in-house donation coordinator initiated education program and LIP referral rather than referral by other parties following asystolic death results in higher tissue donation rates.

A comparison of pain scores and medication use in patients undergoing single-bundle or double-bundle anterior cruciate ligament reconstruction.

BACKGROUND: No gold standard exists for the management of postoperative pain following anterior cruciate ligament reconstruction (ACLR). We compared the pain scores and medication use of patients undergoing single-bundle (SB) or double-bundle (DB) ACLR in the acute postoperative period. Pain and medication use was also analyzed for spinal versus general anesthesia approaches within both surgery types. METHODS: We assessed 2 separate cohorts of primary ACLR patients, SB and DB, for 14 days postoperatively. We used a standard logbook to record self-reported pain scores and medication use. Pain was assessed using a 100 mm visual analogue scale (VAS). Medications were divided into 3 categories: oral opioids, oral nonsteroidal anti-inflammatories and acetaminophen. RESULTS: A total of 88 patients undergoing SB and 41 undergoing DB ACLR were included in the study. We found no significant difference in VAS pain scores between the cohorts. Despite similar VAS pain scores, the DB cohort consumed significantly more opioid and analgesia medication (p = 0.011). Patients who underwent DB with spinal anesthesia experienced significantly less pain over the initial 14-day postoperative period than those who received general anesthesia (p < 0.001). CONCLUSION: Adequate pain relief was provided to all ACLR patients in the initial postoperative period. Patients in the DB cohort experienced more pain, as evidenced by the significant diffrence in consumption of opioids and acetaminophen, than the SB cohort. Patients who underwent spinal anesthesia experienced less pain in the acute postoperative period than those who received general anesthesia.

CONTEXTE: Il n'existe pas de norme établie pour la prise en charge de la douleur postopératoire après la reconstruction du ligament croisé antérieur (RLCA). Nous avons comparé les scores de douleur et le recours aux analgésiques chez des patients soumis à une RLCA simple faisceau (SF) ou double faisceau (DF) durant la période postopératoire immédiate. La douleur et l'utilisation des analgésiques ont aussi été analysées en rapport avec l'anesthésie utilisée, rachidienne ou générale, dans les 2 types de chirurgie. MÉTHODES: Nous avons évalué 2 cohortes distinctes de patients soumis à une RLCA primaire, SF et DF, pendant les 14 premiers jours postopératoires. Les patients ont consigné leurs scores de douleur et leur utilisation d'analgésiques dans des carnets de bord standard. La douleur était évaluée au moyen d'une échelle analogique visuelle (ÉAV) de 100 mm. Les analgésiques étaient regroupés sous 3 catégories, soit opiacés oraux, antiinflammatoires non stéroïdiens oraux et acétaminophène. RÉSULTATS: En tout, 88 patients soumis à une RLCA SF et 41 à une RLCA DF ont été inclus dans l'étude. Nous n'avons observé aucune différence significative quant au score de douleur à l'ÉAV entre les cohortes. Malgré des scores de douleur similaires à l'ÉAV, la cohorte soumise à l'intervention DF a utilisé significativement plus d'opiacés et autres analgésiques (p = 0.011). Comparativement aux patients sous anesthésie générale, les patients soumis à l'intervention DF sous anesthésie rachidienne ont éprouvé significativement moins de douleur au cours des 14 premiers jours postopératoires (p < 0.001). CONCLUSION: Tous les patients qui ont subi une RLCA ont obtenu un soulagement adéquat de leur douleur durant la période postopératoire initiale. Les patients de la cohorte DF ont éprouvé davantage de douleur, comme en témoigne la différence significative de consommation d'opiacés et d'acétaminophène comparativement à la cohorte SF. Les patients qui ont subi une anesthésie rachidienne ont éprouvé moins de douleur pendant la période postopératoire immédiate, comparativement aux patients sous anesthésie générale.

A single-arm clinical trial of a 48-hour intravenous N-acetylcysteine protocol for treatment of acetaminophen poisoning.

INTRODUCTION: Acetylcysteine prevents hepatic injury when administered soon after acetaminophen overdose. The most commonly used treatment protocols are a 72-hour oral and a 21-hour intravenous (IV) protocol. Between 1984 and 1994, 409 patients were enrolled in a study to describe the outcomes of patients who were treated using a 48-hour IV protocol. In 1991, an interim analysis reported the first 223 patients. The objective of this manuscript is to report the rates of hepatotoxicity and adverse events occurring during a 48-hour IV acetylcysteine protocol in the entire 409 patient cohort. METHODS: This was a multicenter, single-arm, open-label clinical trial enrolling patients who presented with a toxic serum acetaminophen concentration within 24 h of acute acetaminophen ingestion. Patients were treated with 140 mg/kg loading dose followed by 70 mg/kg every 4 h for 12 doses. Serum aminotransferase activities were measured every 8 h during the protocol, and adverse events were recorded. The primary outcome was the percentage of subjects who developed hepatotoxicity defined as a peak serum aminotransferase greater than 1000 IU/L. RESULTS: Four hundred and nine patients were enrolled, and 309 met inclusion for the outcome analysis. The overall percentage of patients developing hepatotoxicity was 18.1%, and 3.4% of patients treated within 10 h developed hepatotoxicity. One acetaminophen-related death occurred in a patient treated at 22 h. Adverse events occurred in 28.9% of enrolled subjects; the most common adverse events were nausea, vomiting, and flushing, and no events were rated as serious by the investigator. CONCLUSIONS: Acetaminophen-overdosed patients treated with IV acetylcysteine administered as 140 mg/kg loading dose followed by 70 mg/kg every 4 h for 12 doses had a low rate of hepatotoxicity and few adverse events. This protocol delivers a higher dose of acetylcysteine which may be useful in selected cases involving very large overdoses.

Introduction of a classification system for patients with patellofemoral instability (WARPS and STAID).

PURPOSE: The primary purpose of this paper is to introduce the WARPS/STAID classification system for patellofemoral instability. The secondary purpose is to establish the validity and reliability of the WARPS/STAID classification system. METHODS: Patients (n = 31) with a confirmed diagnosis of patellofemoral instability underwent a thorough knee history and physical examination with 3 raters. The raters graded each component of the WARPS/STAID classification system on a visual analogue scale (VAS). A single Global VAS WARPS/STAID score was graded after all other components of the classification system were completed. Intraclass correlation coefficient (ICC 2, 3) was calculated for each metric of the classification scale and for the Global score. Concurrent validity was assessed by correlating the WARPS/STAID score with the Kujala score. Subjects were assigned to one of three categories (WARPS, STAID, or mixed characteristics) according to the Total WARPS/STAID score to determine the level of agreement between the three raters. RESULTS: Intraclass correlation coefficient (ICC 2, 3) of the WARPS/STAID classification continuum ranged between 0.73 and 0.91 for the individual metrics of the classification. The ICC (2, 3) for the Global WARPS/STAID score was 0.75. The mean Kujala score (m = 61, SD 18) was significantly correlated with the total WARPS/STAID score (r = 0.387, p < 0.05). The majority of subjects were assigned to either the WARPS or STAID categories. CONCLUSION: This study introduced the WARPS/STAID classification system and established both validity and reliability in subjects with patellofemoral instability. LEVEL OF EVIDENCE: II.

Initial validity and reliability of the Banff Patella Instability Instrument.

BACKGROUND: Patellofemoral instability is a well-recognized problem, but there are currently no published patient-reported quality of life outcome measures that are disease specific for the treatment of this population. PURPOSE: To establish the content validity, initial construct validity, and initial reliability of the Banff Patella Instability Instrument (BPII). STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: The content of the BPII was validated using a modified 3-stage Ebel procedure and analysis of floor and ceiling effects. As a measure of internal consistency, the Cronbach α was utilized to assess how reliably the 32 items of the questionnaire measured a similar construct. Test-retest reliability of the BPII was calculated using an intraclass correlation coefficient (ICC). Construct validity was evaluated on 150 questionnaires completed by patients with a confirmed diagnosis of patellofemoral instability. A one-way between-group analysis of variance was employed to determine if the BPII was able to differentiate between patients presenting at the initial orthopaedic consultation relative to patients presenting at 6 months and 12 months postoperatively. RESULTS: Content validity was clearly established as each item in the BPII achieved a minimum of 83.3% agreement (range, 83.3%-100%) for relevance among the expert panelists. The average agreement was 96.9%; 24 items achieved 100% agreement. There was no evidence of floor or ceiling effects. Reliability (internal consistency) of the BPII was established at the initial orthopaedic consultation (α = .91), 6 months postoperatively (α = .97), and 12 months postoperatively (α = .97). Test-retest analysis resulted in an ICC of 0.98 between tests. Construct validity was established as there was a statistically significant difference in BPII scores at the initial orthopaedic consultation and 6-month and 12-month postoperative appointments (F2,146 = 75.62; P < .001). CONCLUSION: The BPII demonstrates content validity, strong initial reliability, and a statistically significant level of construct validity in patients with patellofemoral instability. This population includes patients with recurrent patellofemoral instability as well as surgically stabilized patients.

Budget cuts and U.S. Poison Centers - regional challenges create a nationwide problem.

Federal funding of poison centers (PCs) in the United States was established in 2000 through the Poison Control Center Enhancement and Awareness Act. Unfortunately, the problems with financial stability of PCs that this legislation was intended to improve persist because of continued reliance on fragile local funding sources. In the past few months budget cuts have had an impact on PC activity and threaten the continued existence of a nationwide network of PCs in the United States. This commentary discusses the problems faced by PCs in this changing environment and illustrates the many competing tasks that the PC network performs for the U.S. population. PCs face continuing challenges in coming months and a unified approach at a national level may provide the best opportunity for a solution to this crisis.

Spatial and genetic structure of host-associated differentiation in the parasitoid Copidosoma gelechiae.

Host-associated differentiation (HAD) appears to be an important driver of diversification in the hyperdiverse phytophagous and parasitoid insects. The gallmaking moth Gnorimoschema gallaesolidaginis has undergone HAD on two sympatric goldenrods (Solidago), and HAD has also been documented in its parasitoid Copidosoma gelechiae, with the intriguing suggestion that differentiation has proceeded independently in multiple populations. We tested this suggestion with analysis of Amplified Fragment Length Polymorphism (AFLP) markers for C. gelechiae collections from the midwestern and northeastern United States and eastern Canada. AFLP data were consistent with the existence of HAD, with between-host F(ST) significant before Bonferroni correction in two of seven sympatric populations. amova analysis strongly rejected a model of HAD with a single historical origin, and thus supported the repeated-HAD hypothesis. Copidosoma gelechiae shows significant host-associated divergence at a number of allozyme loci (Stireman et al., 2006), but only weak evidence via AFLPs for genome-wide differentiation, suggesting that this species is at a very early stage of HAD.

Knee immobilization for pain control after a hamstring tendon anterior cruciate ligament reconstruction: a randomized clinical trial.

BACKGROUND: This study will attempt to evaluate the efficacy of knee immobilization on patient pain levels after an anterior cruciate ligament reconstruction. HYPOTHESIS: There is no difference in visual analog scale pain scores 2 days after anterior cruciate ligament reconstruction between patients who wear a knee immobilizer and those who do not wear a knee immobilizer. STUDY DESIGN: Randomized clinical trial; Level of evidence, 1. METHODS: Patients aged 18 to 40 years who met study inclusion criteria were eligible. Patients meeting intraoperative inclusion criteria were randomized (immobilizer or no immobilizer) after wound closure. The immobilizer used was a soft, unhinged brace with Velcro straps. Preoperative, intraoperative, and postoperative protocols were standardized. The primary outcome was patient self-assessed pain using a 0-to-100-mm visual analog scale at day 2 after surgery. Secondary outcomes included pain and analgesic use in the first 14 days after surgery, complications, and range of motion (approximately 3 weeks postoperatively). A sample size estimate was calculated and resulted in the need for 44 patients per group. RESULTS: A total of 102 patients were enrolled; 88 patients were randomized, and 14 were excluded intraoperatively. There was no difference in mean visual analog scale pain scores at 2 days after surgery between immobilized and nonimmobilized patients (32.6 and 35.2, respectively; P = .59; difference, -2.6; 95% confidence interval, -12.2 to 6.9). There were no differences between groups in medication consumed, range of motion, or complications. Pain and analgesic use were the same for both groups at 7 and 14 days postoperatively. CONCLUSION: No differences in pain or any of the secondary outcomes were detected between immobilized and nonimmobilized patients at any point during the first 14 days after anterior cruciate ligament reconstruction.

Emerging patterns in the comparative analysis of phylogenetic community structure.

The analysis of the phylogenetic structure of communities can help reveal contemporary ecological interactions, as well as link community ecology with biogeography and the study of character evolution. The number of studies employing this broad approach has increased to the point where comparison of their results can now be used to highlight successes and deficiencies in the approach, and to detect emerging patterns in community organization. We review studies of the phylogenetic structure of communities of different major taxa and trophic levels, across different spatial and phylogenetic scales, and using different metrics and null models. Twenty-three of 39 studies (59%) find evidence for phylogenetic clustering in contemporary communities, but terrestrial and/or plant systems are heavily over-represented among published studies. Experimental investigations, although uncommon at present, hold promise for unravelling mechanisms underlying the phylogenetic community structure patterns observed in community surveys. We discuss the relationship between metrics of phylogenetic clustering and tree balance and explore the various emerging biases in taxonomy and pitfalls of scale. Finally, we look beyond one-dimensional metrics of phylogenetic structure towards multivariate descriptors that better capture the variety of ecological behaviours likely to be exhibited in communities of species with hundreds of millions of years of independent evolution.

Report of a National Conference on Donation after cardiac death.

A national conference on organ donation after cardiac death (DCD) was convened to expand the practice of DCD in the continuum of quality end-of-life care. This national conference affirmed the ethical propriety of DCD as not violating the dead donor rule. Further, by new developments not previously reported, the conference resolved controversy regarding the period of circulatory cessation that determines death and allows administration of pre-recovery pharmacologic agents, it established conditions of DCD eligibility, it presented current data regarding the successful transplantation of organs from DCD, it proposed a new framework of data reporting regarding ischemic events, it made specific recommendations to agencies and organizations to remove barriers to DCD, it brought guidance regarding organ allocation and the process of informed consent and it set an action plan to address media issues. When a consensual decision is made to withdraw life support by the attending physician and patient or by the attending physician and a family member or surrogate (particularly in an intensive care unit), a routine opportunity for DCD should be available to honor the deceased donor's wishes in every donor service area (DSA) of the United States.

An initiative to reform senior house officer training in histopathology.

Senior house officer schools in histopathology have been established in Leeds, Leicester and Southampton, each training six new recruits each year. Nine hours of protected teaching time is provided each week giving a ratio of apprenticeship learning to formal teaching of 3:1. Evaluations have been very positive. Much of this success is attributed to careful planning and adequate funding. This may be a useful model for other specialties to follow.

Corridor consultations and the medical microbiological record: is patient safety at risk?

The performance procedures of the General Medical Council are aimed at identifying seriously deficient performance in a doctor. The performance procedures require the medical record to be of a standard that enables the next doctor seeing the patient to give adequate care based on the available information. Setting standards for microbiological record keeping has proved difficult. Over one fifth of practising medical microbiologists (including virologists) in the UK (139 of 676) responded to a survey undertaken by the working group developing the performance procedures for microbiology, to identify current practice and to develop recommendations for agreement within the profession about the standards of the microbiological record. The cumulative frequency for the surveyed recording methods used indicated that at various times 65% (90 of 139) of respondents used a daybook, 62% (86 of 139) used the back of the clinical request card, 57% (79 of 139) used a computer record, and 22% (30 of 139) used an index card system to record microbiological advice, suggesting wide variability in relation to how medical microbiologists maintain clinical records.

Substitution of a nursing-led inpatient unit for acute services: randomized controlled trial of outcomes and cost of nursing-led intermediate care.

OBJECTIVES: To evaluate the outcome and cost of transfer to a nursing-led inpatient unit for 'intermediate care'. The unit was designed to replace a period of care in acute hospital wards and promote recovery before discharge to the community. DESIGN: Randomized controlled trial comparing outcomes of care on a nursing-led inpatient unit with the system of consultant-managed care on a range of acute hospital wards. SETTING: hospital wards in an acute inner-London National Health Service trust. SUBJECTS: 175 patients assessed to be medically stable but requiring further inpatient care, referred to the unit from acute wards. INTERVENTION: 89 patients were randomly allocated to care on the unit (nursing-led care with no routine medical intervention) and 86 to usual hospital care. MAIN OUTCOME MEASURES: Length of hospital stay, discharge destination, functional dependence (Barthel index) and direct healthcare costs. RESULTS: Care in the unit had no significant impact on discharge destination or dependence. Length of inpatient stay was significantly increased for the treatment group (P=0.036; 95% confidence interval 1.1-20.7 days). The daily cost of care was lower on the unit, but the mean total cost was pound sterlings 1044 higher-although the difference from the control was not significant (P=0.150; 95% confidence interval - pound sterlings 382 to pound sterlings 2471). CONCLUSIONS: The nursing-led inpatient unit led to longer hospital stays. Since length of stay is the main driver of costs, this model of care-at least as implemented here-may be more costly. However, since the unit may substitute for both secondary and primary care, longer-term follow-up is needed to determine whether patients are better prepared for discharge under this model of care, resulting in reduced primary-care costs.

Continuous quality improvement: educating towards a culture of clinical governance.

The National Health Service in England and Wales has recently adopted a policy aimed at embedding continuous quality improvement (CQI) at all levels and across all services. The key goal is to achieve changes in practice which improve patient outcomes. This paper describes the use of a training course for multiprofessional groups of participants tailored to offer them relevant knowledge, management and team working skills, and approaches to personal and career development. These were intended to assist them in changing their practice for the benefit of patients. The participants rated the course highly in fulfilling its objectives. One cohort followed up for 6 months named changes in practice which related specifically to learning from the course. This paper shows the important contribution of multiprofessional learning to CQI and presents a useful method of evaluating links between learning and performance.

Naloxone blocks transferred preconditioning in isolated rabbit hearts.

We have shown that the cardioprotective benefits of ischemic preconditioning (PC) can be transferred from PC to virgin acceptor hearts via coronary effluent transfusion, implicating the presence of hormonal preconditioning factor(s). Using isolated buffer-perfused rabbit hearts, our aims were to: (1) determine whether the protective factor(s) could be concentrated and recovered by reverse phase chromatography and (2) whether opioid receptor activation contributes to this transferred cardioprotection. Material released into the coronary effluent during PC ischemia/reperfusion or normoxic perfusion was concentrated by reverse phase chromatography. In phase one, hearts received no intervention (controls), PC ischemia, concentrate generated from normoxic hearts (normoxic acceptors) or concentrate from PC hearts (PC acceptors). All hearts underwent 40 min of global ischemia, and area of necrosis (AN) was delineated by tetrazolium staining. In phase two, three additional groups of hearts (control, PC and PC acceptors) received the opioid antagonist naloxone (2 microM) throughout the intervention phase. Treatment with normoxic concentrate had no effect on infarct size: (AN: normoxic acceptors 39+/-8%; control 42+/-8%). In contrast, treatment with PC concentrate evoked cardioprotection equivalent to that afforded by conventional PC (AN 19+/-5% and 21+/-6% respectively P<0.05 v control). Naloxone had no effect on infarct size in controls, and did not inhibit preconditioning. However, naloxone abrogated the protection achieved by transfer of PC concentrate (AN: 44+/-7%). These results indicate that PC concentrate evokes a cardioprotective effect via a mechanism requiring an intact opioid receptor system.

Catheter-related infection: diagnosis, prevention and treatment.

INTRODUCTION: Catheter infection continues to be a serious problem in critically ill patients. This review will examine the incidence, epidemiology, microbiology, diagnosis, risk factors for and treatment of catheter-related bloodstream infections. METHODS: Relevant articles were culled from a Medline search and other review articles on catheter-related infection. Important abstracts presented within the past year were included in the review if the data had not been published in a peer-reviewed journal. RESULTS: Catheter-related bloodstream infections (CRBSI) increase morbidity and the cost of care of patients. The predominant organisms associated with CRBSI are coagulase negative staphylococci, enterococci and Staphylococcus aureus. Diagnosis usually requires catheter removal and culture but newer techniques such as "differential time to positivity" may permit diagnosis of CRBSI in situ. Reducing risk factors for infection are important: education of house staff, use of the subclavian insertion site, skin preparation with chlorhexidine solutions, use of maximum barrier precautions during catheter insertion and catheter maintenance with chlorhexidine sponges. If infection rates are still high after institution of these measures, use of antiseptic or antibiotic-impregnated catheters should be considered. Treatment of CRBSI in critically ill patients mandates catheter removal and treatment with systemic antibiotics. CONCLUSIONS: The best treatment for CRBSI is prevention. Ongoing studies are evaluating the effectiveness of newer antiseptic catheters, the risk of developing antibiotic resistance when using antibiotic-impregnated catheters and the contribution of multiple interventions on the development of CRBSI.

Application of fiberoptic sensors for the study of hepatic dysoxia in swine hemorrhagic shock.

OBJECTIVES: To determine whether the simultaneous measurement of tissue pH, Pco2, and Po2 with a multiple-parameter fiberoptic sensor can be used to indicate the onset of hepatic dysoxia, to determine critical values, and to assess their use in predicting negative outcomes. DESIGN: Prospective animal study. SETTING: University research laboratory. SUBJECTS: Fourteen Yorkshire swine. INTERVENTIONS: Hemorrhagic shock (n = 11) was induced over 15 mins to lower systolic blood pressure to 40 mm Hg and was maintained for 30, 60, or 90 mins. Resuscitation was achieved with shed blood and warm saline to maintain mean pressure >60 mm Hg for 120 mins. Sham animals (n = 3) were subjected to 90 mins of sham shock, followed by a 120-min recovery period. MEASUREMENTS AND MAIN RESULTS: The multiple-parameter sensor continuously measured tissue pH, Pco2, and Po2. pH and Pco2, indicators of anaerobic metabolism, were plotted against tissue Po2. All shocked animals, but no sham animals, showed a biphasic relationship between Po2 and both pH and Pco2. Curves were fit to both an exponential and a dual-line linear function to determine critical values for Po2, pH, and Pco2. The length of time the animal was dysoxic was evaluated as a predictor of negative outcome. Critical values determined from the exponential models were more sensitive indicators of negative outcome than values determined from the linear model and more sensitive than arterial lactate and tonometric intramucosal pH and Pco2. CONCLUSIONS: The multiple-parameter sensor offers the unique opportunity to study solid as well as hollow organ dysoxia through the simultaneous measurement of interstitial pH, Pco2, and Po2 in a small tissue region. The gradual transition from sufficient oxygen availability to dysoxia as a result of hemorrhage was better described by an exponential equation. The length of time that pH was below or Pco2 was above the critical value determined from the exponential model was predictive of a negative outcome.