Is there a correlation between obstructive sleep-apnea syndrome severity and prolidase activity as an oxidative stress marker?

OBJECTIVE: Obstructive sleep apnea syndrome (OSAS) is a highly prevalent breathing disorder in sleep. The aim of this study was to evaluate the relationship between OSAS and prolidase activity, the oxidative stress index (OSI), total antioxidative capacity (TAC), total oxidative capacity (TOC) and the carotid intima media thickness (CIMT). METHOD: : After night polysomnography, 74 people were diagnosed with OSAS and simple snoring. Plasma prolidase activities, TAC and TOC were measured in blood samples taken in the morning after the sleep study. The patients' bilateral common carotid arteries were scanned. RESULTS: In total, 56 patients were in OSAS group [13 subjects 23.2% mild, 19 subjects 33.9% moderate, 24 subjects 42.8% severe] and 18 in simple snoring control group. The mean Prolidase, TOC, TAC and OSI levels were 744.7 ± 156.8, 59.2 ± 19.2, 2.12 ± 0.41, 3.12 ± 1.03, in the mild OSAS group, 761.6 ± 114.4, 57.9 ± 18.3, 2.03 ± 0.37, 3.15 ± 0.8, in the moderate OSAS group, 754.08 ± 133.9, 51.15 ± 12.1, 1.97 ± 0.27, 2.8 ± 0.82, in the severe OSAS group, and 711.9 ± 139, 52.3 ± 15.1, 1.83 ± 0.32, 3.06 ± 0.92 in the control group, respectively. Mean CIMT measurements were 0.71(±0,13) in the OSAS group and 0.76(±0.07) in the control group. CONCLUSION: There was no difference between the control and OSAS groups in terms of the parameters studied. Further studies should be undertaken in order to clarify the relation.

Process of care events in transplantation: effects on the cost of hospitalization.

Deviations in the processes of healthcare delivery that affect patient outcomes are recognized to have an impact on the cost of hospitalization. Whether deviations that do not affect patient outcome affects cost has not been studied. We have analyzed process of care (POC) events that were reported in a large transplantation service (n = 3,012) in 2005, delineating whether or not there was a health consequence of the event and assessing the impact on hospital resource utilization. Propensity score matching was used to adjust for patient differences. The rate of POC events varied by transplanted organ: from 10.8 per 1000 patient days (kidney) to 17.3 (liver). The probability of a POC event increased with severity of illness. The majority (81.5%) of the POC events had no apparent effect on patients' health (63.6% no effect and 17.9% unknown). POC events were associated with longer length of stay (LOS) and higher costs independent of whether there was a patient health impact. Multiple events during the same hospitalization were associated with the highest impact on LOS and cost. POC events in transplantation occur frequently, more often in sicker patients and, although the majority of POC events do not harm the patient, their effect on resource utilization is significant.

Getting the right blood to the right patient: the contribution of near-miss event reporting and barrier analysis.

Safety and reliability in blood transfusion are not static, but are dynamic non-events. Since performance deviations continually occur in complex systems, their detection and correction must be accomplished over and over again. Non-conformance must be detected early enough to allow for recovery or mitigation. Near-miss events afford early detection of possible system weaknesses and provide an early chance at correction. National event reporting systems, both voluntary and involuntary, have begun to include near-miss reporting in their classification schemes, raising awareness for their detection. MERS-TM is a voluntary safety reporting initiative in transfusion. Currently 22 hospitals submit reports anonymously to a central database which supports analysis of a hospital's own data and that of an aggregate database. The system encourages reporting of near-miss events, where the patient is protected from receiving an unsuitable or incorrect blood component due to a planned or unplanned recovery step. MERS-TM data suggest approximately 90% of events are near-misses, with 10% caught after issue but before transfusion. Near-miss reporting may increase total reports ten-fold. The ratio of near-misses to events with harm is 339:1, consistent with other industries' ratio of 300:1, which has been proposed as a measure of reporting in event reporting systems. Use of a risk matrix and an event's relation to protective barriers allow prioritization of these events. Near-misses recovered by planned barriers occur ten times more frequently then unplanned recoveries. A bedside check of the patient's identity with that on the blood component is an essential, final barrier. How the typical two person check is performed, is critical. Even properly done, this check is ineffective against sampling and testing errors. Blood testing at bedside just prior to transfusion minimizes the risk of such upstream events. However, even with simple and well designed devices, training may be a critical issue. Sample errors account for more than half of reported events. The most dangerous miscollection is a blood sample passing acceptance with no previous patient results for comparison. Bar code labels or collection of a second sample may counter this upstream vulnerability. Further upstream barriers have been proposed to counter the precariousness of urgent blood sample collection in a changing unstable situation. One, a linking device, allows safer labeling of tubes away from the bedside, the second, a forcing function, prevents omission of critical patient identification steps. Errors in the blood bank itself account for 15% of errors with a high potential severity. In one such event, a component incorrectly issued, but safely detected prior to transfusion, focused attention on multitasking's contribution to laboratory error. In sum, use of near-miss information, by enhancing barriers supporting error prevention and mitigation, increases our capacity to get the right blood to the right patient.

Event reporting systems: MERS-TM, surveillance--seeing and using the data below the waterline.

A significant variability in reporting rates, particularly of near-miss events, limits the quantitative reliability of event reporting. Organizations tend to disregard events such as near misses if they are "below the waterline", and outside their classification schemes. High reliability organizations, on the other hand, see near misses as valuable information regarding a system's weaknesses. Another value of near-miss reporting is the opportunity to study recovery factors in order to promote recovery once failure occurs. Since transfusion procedures are well-practised routines, they are often performed as automatic behaviours, vulnerable to interruption and unanticipated occurrences. Data fed back from near-miss events are a useful means of countering this, by maintaining an attitude of alertness in task performance.

Organization of event reporting data for sense making and system improvement.

Feedback and demonstrable local usefulness are critical determinants for adopting event reporting by an organization. The classification schemes used by an organization determine whether an event is recognized or ignored. Near miss events, by their frequency and information content concerning recovery, merit recognition. "Just" cultures are learning cultures that provide a safe haven in which errors may be reported without the fear of disciplinary action in events without reckless behavior. As event report databases grow, selection and prioritization for in depth investigation become critical issues. Risk assessment tools and similarity matching approaches such as in case based reasoning are useful in this regard. Root cause analysis provides a framework for the collection, analysis, and trending of event data. The importance of both internal and external risk communication as valuable reporting system components may be overlooked.

Reporting of near-miss events for transfusion medicine: improving transfusion safety.

BACKGROUND: Half of the reported serious adverse events from transfusion are a consequence of medical error. A no-fault medical-event reporting system for transfusion medicine (MERS-TM) was developed to capture and analyze both near-miss and actual transfusion-related errors. STUDY DESIGN AND METHODS: A prospective audit of transfusion-related errors was performed to determine the ability of MERS-TM to identify the frequency and patterns of errors. RESULTS: Events and near-miss events (total, 819) were recorded for a period of 19 months (median, 51/month). No serious adverse patient outcome occurred, despite these events, with the transfusion of 17,465 units of RBCs. Sixty-one events (7.4%) were potentially life-threatening or could have led to permanent injury (severity Level 1). Of most concern were 3 samples collected from the wrong patient, 13 mislabeled samples, and 22 requests for blood for the wrong patient. Near-miss events were five times more frequent than actual transfusion errors, and 68 percent of errors were detected before blood was issued. Sixty-one percent of events originated from patient areas, 35 percent from the blood bank, and 4 percent from the blood supplier or other hospitals. Repeat collection was required for 1 of every 94 samples, and 1 in 346 requests for blood components was incorrect. Education of nurses and alterations to blood bank forms were not by themselves effective in reducing severe errors. An artifactual 50-percent reduction in the number of errors reported was noted during a 6-month period when two chief members of the event-reporting team were on temporary leave. CONCLUSION: The MERS-TM allowed the recognition and analysis of errors, determination of patterns of errors, and monitoring for changes in frequency after corrective action was implemented. Although no permanent injury resulted from the 819 events, innovative mechanisms must be designed to prevent these errors, instead of relying on faulty informal checks to capture errors after they occur.

Protein C and S deficiency.

Protein C and S deficiency states predispose affected individuals to thrombosis, especially venous thrombosis of the lower extremities, usually beginning in the teenage years. Treatment of these patients is generally with oral anticoagulation, following initial heparinization. The classification of the deficiency states is dependent upon determination of the quantity and functional activity of either protein.

Identification and classification of the causes of events in transfusion medicine.

BACKGROUND: Transfusion medicine lacks a standard method for the systematic collection and analysis of event reports. Review of event reports from the Food and Drug Administration (FDA) showed a relative paucity of information on event causation. Thus, a causal analysis method was developed as part of a prototype Medical Event Reporting System for Transfusion Medicine (MERS-TM). STUDY DESIGN AND METHODS: MERS-TM functions within existing quality assurance systems and utilizes descriptive coding and causal classification schemes. The descriptive classification system, based upon current FDA coding, was modified to meet participant needs. The Eindhoven Classification Model (Medical Version) was adopted for causal classification and analysis. Inter-rater reliability for the MERS-TM and among participating organizations was performed with the development group in the United States and with a safety science research group in the Netherlands. The MERS-TM was then tested with events reported by participants. RESULTS: Data from 503 event reports from two blood centers and two transfusion services are discussed. The data showed multiple causes for events and more latent causes than previously recognized. The distribution of causes was remarkably similar to that in an industrial setting outside of medicine that uses the same classification approach. There was a high degree of inter-rater reliability when the same events were analyzed by quality assurance personnel in different participating organizations. These personnel found the method practical and useful for providing new insights into conditions producing undesired events. CONCLUSION: A generally applicable and reliable method for identifying and quantifying problems that exist throughout transfusion medicine will be a valuable addition to event reporting activity. By using a common taxonomy, participants can compare their experience with that of others. If proven as readily implementable and useful as shown in initial studies, MERS-TM is a potential standard for transfusion medicine.

The attributes of medical event-reporting systems: experience with a prototype medical event-reporting system for transfusion medicine.

OBJECTIVE: To design, develop, and implement a prototype medical event-reporting system for use in transfusion medicine to improve transfusion safety by studying incidents and errors. METHODS: The IDEALS concept of design was used to identify specifications for the event-reporting system, and a Delphi and subsequent nominal group technique meetings were used to reach consensus on the development of the system. An interdisciplinary panel of experts from aviation safety, nuclear power, cognitive psychology, artificial intelligence, and education and representatives of major transfusion medicine organizations participated in the development process. Setting.- Three blood centers and three hospital transfusion services implemented the reporting system. RESULTS: A working prototype event-reporting system was recommended and implemented. The system has seven components: detection, selection, description, classification, computation, interpretation, and local evaluation. Its unique features include no-fault reporting initiated by the individual discovering the event, who submits a report that is investigated by local quality assurance personnel and forwarded to a nonregulatory central system for computation and interpretation. CONCLUSIONS: An event-reporting system incorporated into present quality assurance and risk management efforts can help organizations address system structural and procedural weakness where the potential for errors can adversely affect health care outcomes. Input from the end users of the system as well as from external experts should enable this reporting system to serve as a useful model for others who may develop event-reporting systems in other medical domains.

Inhibitory effect of 0 degree C storage on the proliferation of Yersinia enterocolitica in donated blood.

BACKGROUND: Yersinia enterocolitica is frequently identified in cases of bacterial sepsis due to red cell transfusion. One of the features that makes Y. enterocolitica particularly dangerous is that, unlike most other bacterial contaminants of blood components, this organism can actively multiply in currently recommended refrigerator temperatures (1-6 degrees C). The effect of a colder than normal storage temperature on Y. enterocolitica growth was investigated to determine whether bacteria growth could be reduced or inhibited at 0 degree C. STUDY DESIGN AND METHODS: Twenty-four units of freshly collected donated blood were obtained. Three sets of 7 units each were inoculated with Y. enterocolitica O:3, Y. enterocolitica O:20, and Y. enterocolitica O:5, 27, respectively. The remaining 3 units served as uninoculated controls. Each of the 24 bags was split into two equal aliquots, with one aliquot stored at 4 degrees C and the other at 0 degree C. Bacteria growth was measured twice weekly for 6 weeks. Endotoxin and hemoglobin levels were also measured at selected intervals. RESULTS: Bacteria growth was detected earlier and in higher concentrations in the aliquots stored at 4 degrees C. Twenty-two of the 42 inoculated aliquots had measureable bacteria growth. Thirteen aliquots had been maintained at 4 degrees C, and nine had been stored at 0 degree C. Sixteen of these 22 aliquots were matched pairs. Exponential growth was detected after 14 to 32 days in the 4 degrees C aliquots and after 28 to 39 days in the 0 degree C aliquots. Final bacteria counts were much higher in the 4 degrees C aliquots (10(5)-10(14) colony-forming units/mL) than in the 0 degree C aliquots (10(1)-10(4) colony-forming units/mL) on Day 42. Endotoxin was present in all 13 of the 4 degrees C aliquots with actively growing Y. enterocolitica. CONCLUSION: Storage of red cells at 0 degree C markedly prolongs the time required for Y. enterocolitica to achieve exponential grwoth and results in lower concentrations of bacteria.

Fatal air embolism due to perioperative blood recovery.

This study was initiated to investigate the incidence of acute mortality from air embolism associated with perioperative blood recovery and the causative factors and common characteristics of such fatalities. All facilities providing transfusion services in New York State are required to report severe adverse reactions to, and the total number of, transfusion and blood recovery procedures performed. Relevant data for the period from January 1990 to June 1995 were tabulated. During this time, 127,586 perioperative blood recovery procedures were performed, and 8,955,619 conventional blood components were transfused. The frequency of fatal air embolism after readministration of recovered blood was approximately 1:30,000-1:38,000; none followed conventional transfusion. Characteristics common to the fatalities (including an additional case reported before the study interval) were examined; all involved reinfusion of recovered blood under pressure. In the population studied, the incidence of fatal air embolism after the perioperative readministration of recovered blood was significantly higher than that after conventional transfusion. A model of such a system demonstrated that as much as 200 mL of air could enter the circulation in as little as 4 s, rendering visual detection and intervention extremely difficult. Education and guidelines to reduce the risk and mortality associated with this procedure are recommended.

Screening for hearing loss in juvenile detention centers.

Results of hearing screenings for 226 incarcerated adolescents are presented. Screenings consisted of visual otoscopy check, pure-tone screening, and tympanometry. Failures were defined as excessive cerumen impeding a clear view of the tympanum, failure to respond at 25 dB HL for 1000 through 6000 Hz, or a Jerger Type B or C tympanogram. An overall failure rate of 35.5 percent was found, with 9.8 percent failing otoscopy, 7.5 percent failing tympanometry, and 25.3 percent failing pure-tone screening. Implications for medical and audiologic evaluation in the population are discussed.

Lipoprotein (a), homocysteine, and hypercoagulable states in young men with premature peripheral atherosclerosis: a prospective, controlled analysis.

PURPOSE: Elevated lipoprotein (a) (Lp[a]) lipoprotein, total homocysteine, and hypercoagulable states (HCS) have all been implicated as risk factors for premature-onset atherosclerosis. This study was performed to determine the prevalence of these abnormalities in young men with chronic lower extremity ischemia (peripheral vascular disease [PVD]) and to determine their relative strengths as risk factors for premature peripheral atherosclerosis. METHODS: We analyzed 50 young white men (aged 45 years or younger at onset of symptoms) and compared them with 45 age-matched white male control subjects. RESULTS: Atherosclerotic risk factors were similar in both groups. The mean (+/- SEM) Lp(a) lipoprotein level was 36 +/- 6 mg/dl among the study patients, compared with 14 +/- 2 mg/dl among control subjects (p = 0.02, Mann-Whitney). Twenty (40%) study patients and seven (16%) control subjects had Lp(a) lipoprotein levels of 30 mg/dl or greater (atherosclerotic risk threshold) (p = 0.01, odds ratio = 3.62, confidence interval (CI) 1.4 to 9.5). Positive HCS panels (antiphospholipid antibodies or deficiencies in antithrombin III, protein C, or protein S) were nearly twice as prevalent in study patients (n = 15, 30%) as in controls (n = 8, 18%), but this difference did not achieve statistical significance. The mean total plasma homocysteine level among the study patients was 15.9 +/- 0.9 mumol/L, which was not significantly different from the mean control value of 14.7 +/- 0.7 mumol/L. Lp(a) lipoprotein was related to risk of premature PVD through a linear logistic relationship (p = 0.003, odds ratio per each 1 mg/dl Lp(a) change was 1.03, CI 1.0 to 1.1). Multivariate analysis with stepwise logistic regression selected two variables: Lp(a) lipoprotein > or = 30 mg/dl (p = 0.01, odds ratio = 3.6, CI 1.3 to 9.9) and family history (p = 0.07, odds ratio = 2.2, CI 0.9 to 5.3). Tests of interaction demonstrated no effect between Lp(a) lipoprotein, HCS, and homocysteine. CONCLUSIONS: Lp(a) lipoprotein of 30 mg/dl or greater is an independent risk factor for premature peripheral atherosclerosis in men. None of the other examined variables exhibited a significant association with premature PVD.

Psychostimulants apparently reverse sexual dysfunction secondary to selective serotonin re-uptake inhibitors.

Sexual dysfunction secondary to selective serotonin re-uptake inhibitors (SSRIs) is an almost universal, yet pooly understood phenomenon. Not uncommonly, this unpleasant side effect leads to noncompliance. Since SSRIs have been so successful clinically, it is time to find a safe and effective treatment for this side effect. This paper reports on five cases in which low dosages of the psychostimulants, dextroamphetamine and methylphenidate, administered on a p.r.n. basis, reversed the sexually inhibiting side effects of the SSRIs fluxetine, setraline, and paroxetine in patients with and without attention deficit hyperactivity disorder. In addition, the women experienced enhanced levels of arousal, orgasmic sensation and excitement during the resolution phase (afterglow) of the sexual response cycle on psychostimulants, and the men noted firmer erections.

Does observed fertility maximize fitness among New Mexican men? : A test of an optimality model and a new theory of parental investment in the embodied capital of offspring.

Our objective is to test an optimality model of human fertility that specifies the behavioral requirements for fitness maximization in order (a) to determine whether current behavior does maximize fitness and, if not, (b) to use the specific nature of the behavioral deviations from fitness maximization towards the development of models of evolved proximate mechanisms that may have maximized fitness in the past but lead to deviations under present conditions. To test the model we use data from a representative sample of 7,107 men living in Albuquerque, New Mexico, between 1990 and 1993. The model we test proposes that low fertility in modern settings maximizes number of grandchildren as a result of a trade-off between parental fertility and next generation fertility. Results do not show the optimization, although the data do reveal a trade-off between parental fertility and offspring education and income.We propose that two characteristics of modern economies have led to a period of sustained fertility reduction and to a corresponding lack of association between income and fertility. The first is the direct link between costs of investment and wage rates due to the forces of supply and demand for labor in competitive economies. The second is the increasing emphasis on cumulative knowledge, skills, and technologies in the production of resources. Together they produce historically novel conditions. These two features of modern economies may interact with evolved psychological and physiological mechanisms governing fertility and parental investment to produce behavior that maximizes the economic productivity of lineages at the expense of fitness. If cognitive processes evolved to track diminishing returns to parental investment and if physiological processes evolved to regulate fertility in response to nutritional state and patterns of breast feeding, we might expect non-adaptive responses when returns from parental investment do not diminish until extremely high levels are reached. With high economic payoffs from parental investment, people have begun to exercise cognitive regulation of fertility through contraception and family planning practices. Those cognitive processes maynot have evolved to handle fitness trade-offs between fertility and parental investment.

Laboratory assessment of circulating anticoagulants.

Circulating anticoagulants pose challenging conceptual, technical, and interpretive problems in the laboratory. Their sound diagnosis and management depend on a clear understanding of both the in vivo and in vitro manifestations of the three classes of inhibitors (nonspecific, multispecific, and specific) and the entities therein. From the ongoing research, this field will undoubtedly continue to grow in significance and complexity, demanding ever greater laboratory expertise and competence.