Laboratory assessment of the quality of adult and neonatal red cell concentrates manufactured from whole blood, exchange transfusion or intrauterine transfusion red cell units.

BACKGROUND: We evaluated the quality of red cell components in additive solution over 42 days of storage when re-manufactured from neonatal exchange transfusion (ExTx) or intrauterine transfusion (IUT) units on day 7 for issue to adults, neonates or infants. MATERIALS AND METHODS: Red cell concentrates (RCC) manufactured from WB were compared to RCC re-manufactured from ExTx or IUT on day 7, and red cell splits (RCS) manufactured from WB were compared to RCS re-manufactured from ExTx or IUT on day 7. All components were stored at 2-6°C and tested throughout storage until day 42 for in vitro parameters of red cell quality. One RCS manufactured from each of WB, ExTx or IUT, was irradiated on day 14 and tested on day 28 along with a non-irradiated RCS from the same unit. RESULTS: All the re-manufactured arms had no worse haemolysis, red cell microvesicle (RCMV) release or ATP over storage compared to controls. All arms complied with the 0·8% haemolysis UK specification, except for re-manufactured RCS from the IUT arm irradiated on day 14 and tested on day 28. Re-manufactured units had significantly decreased potassium levels compared to control over storage (P < 0·001 all). CONCLUSION: RCC or RCS re-manufactured from ExTx or IUT units on day 7 are suitable for transfusion up to the standard day 35 of storage. Re-manufactured RCS from ExTx units (but not IUT), may be irradiated up to day 14 and stored for 14 days post-irradiation.

Using multiple measures to evaluate a dental faculty development program.

INTRODUCTION: The formal preparation of dental professionals for teaching is increasingly seen as essential to enhance teacher effectiveness and student learning and to promote curricular initiatives. As a result, many dental schools have implemented a variety of faculty development programming. There is a body of literature that describes these programmes, but there is limited rigorous evaluation of them. The use of multiple measures of evaluation helps to compensate for potential inadequacies of individual methods. Analyses with multiple measures provide a more comprehensive view of whether a programme is achieving its learning outcomes. MATERIALS AND METHODS: A dental faculty development programme, Class Advanced Clinical Teaching Scholars (ACTS), at New York University College of Dentistry (NYUCD) was evaluated with four different measures: pre- and post-programme tests of participants' level of relevant pedagogical knowledge, pre- and post-programme objective structured teaching examinations (OSTEs), pre- and post-programme self-assessments of teaching abilities and post-programme participant satisfaction surveys. Two of the measures used a comparison group of faculty. RESULTS: Results revealed that the Class ACTS participants significantly improved their knowledge; observed teaching performance in most teaching domains tested showed significant improvement; there was no significant change in self-assessed teaching abilities after participation; and the course was viewed positively by the participants. CONCLUSION: Class ACTS, an advanced dental faculty development course, has been successfully implemented and evaluated with the use of multiple measures.

Characteristics of effective clinical teachers identified by dental students: a qualitative study.

This qualitative research study identified criteria for clinical teacher quality preferences as perceived by dental students. Third and fourth year dental students at New York University College of Dentistry were given a two question, open-ended survey asking what qualities they liked most and least in a clinical teacher. Responses were collected until data saturation was achieved. A total of 157 respondents provided a total of 995 written comments. Descriptive words within the responses were coded and grouped into key words, according to similar relationships, and further refined into 17 defined categories. Three core themes, Character, Competence and Communication, emerged from these 17 categories, which were validated according to specific references found in the existing educational literature. 'Character' comprised nine of the 17 defined categories: (caring, motivation, empathy, patience, professionalism, available, fairness, happiness, patient-centred) and yielded 59.1% of total student responses; 'Competence' consisted of five categories: knowledgeable, expertise, efficient, skilful, effective (29.2%); and 'Communication' represented the remaining three categories: feedback, approachable and interpersonal communication (11.7%). Positive and negative responses related to the defined category of caring were cited by 59.2% of all students. Motivation was the next highest category, cited by 45.9% of students. Non-cognitive attributes, especially those in the Character theme, comprised the majority of student comments. Because students' perceptions are so critical to understanding clinical teaching effectiveness in dental education, these findings can be used to develop assessments to measure clinical teaching effectiveness, to create criteria for the hiring and promotion of clinical faculty and to plan faculty development programming.

A prospective evaluation of the clinical utility of the lower-extremity injury-severity scores.

BACKGROUND: High-energy trauma to the lower extremity presents challenges with regard to reconstruction and rehabilitation. Failed efforts at limb salvage are associated with increased patient mortality and high hospital costs. Lower-extremity injury-severity scoring systems were developed to assist the surgical team with the initial decision to amputate or salvage a limb. The purpose of the present study was to prospectively evaluate the clinical utility of five lower-extremity injury-severity scoring systems. METHODS: Five hundred and fifty-six high-energy lower-extremity injuries were prospectively evaluated with use of five injury-severity scoring systems for lower-extremity trauma designed to assist in the decision-making process for the care of patients with such injuries. Four hundred and seven limbs remained in the salvage pathway six months after the injury. The sensitivity, specificity, and area under the receiver operating characteristic curve were calculated for the Mangled Extremity Severity Score (MESS); the Limb Salvage Index (LSI); the Predictive Salvage Index (PSI); the Nerve Injury, Ischemia, Soft-Tissue Injury, Skeletal Injury, Shock, and Age of Patient Score (NISSSA); and the Hannover Fracture Scale-97 (HFS-97) for ischemic and nonischemic limbs. The scores were analyzed in two ways: including and excluding limbs that required immediate amputation. RESULTS: The analysis did not validate the clinical utility of any of the lower-extremity injury-severity scores. The high specificity of the scores in all of the patient subgroups did confirm that low scores could be used to predict limb-salvage potential. The converse, however, was not true. The low sensitivity of the indices failed to support the validity of the scores as predictors of amputation. CONCLUSIONS: Lower-extremity injury-severity scores at or above the amputation threshold should be cautiously used by a surgeon who must decide the fate of a lower extremity with a high-energy injury.

Determinants of disability after lower extremity fracture.

BACKGROUND: Factors influencing the progression of physical impairment to patient-perceived disability are not well known. We sought to better understand this relationship in the setting of injury. METHODS: We followed a cohort of 302 patients with lower extremity fractures over a 1-year period. Physical impairment was assessed by range of motion, strength, and pain. Range of motion and strength were assessed together as a proportion of normal function of the extremity (impairment score). Pain was assessed using a Visual Analogue Scale (VAS) pain score. Disability was assessed using the Sickness Impact Profile (SIP), a widely used measure of patient-perceived limitations of everyday activities attributable to illness. The SIP was administered during hospitalization to assess preinjury baseline. Impairment assessment and readministration of the SIP were performed at 12 months after injury. RESULTS: Impairment in leg function (range of motion and strength) was highly correlated (p < 0.001) with overall SIP score at 12 months, but accounted for only 23% of the variance in overall SIP scores. Likewise, VAS pain score was highly correlated (p < 0.001) with overall SIP score at 12 months, but accounted for only 29% of the variance in overall SIP scores. In a multivariate linear regression analysis, variables that were independently associated with overall SIP score included impairment score, VAS pain score, preinjury SIP, poverty status, education status, social support, having hired a lawyer, and involvement with workers' compensation. These variables accounted for 52% of the variance in overall SIP scores at 12 months. CONCLUSION: The degree of physical impairment accounts for only a small amount of the variance in disability from lower extremity fracture. Identifiable patient characteristics including age, socioeconomic status, preinjury health, and social support together with impairment account for over half of the variance in long-term disability. Further research is needed to increase understanding of other factors that influence the progression of impairment to disability, especially those factors that may be amenable to intervention.

Characterization of patients with high-energy lower extremity trauma.

PURPOSE: (a) to report the demographic, socioeconomic, behavioral, social, and vocational characteristics of patients enrolled in a study to examine outcomes after high-energy lower extremity trauma (HELET) and to compare them with the general population; (b) to determine whether characteristics of patients undergoing limb salvage versus amputation after HELET are significantly different from each other. DESIGN AND STUDY POPULATION: A prospective study of 601 patients admitted with high-energy lower extremity trauma to eight Level I trauma centers. PROCEDURES: Patients were evaluated during the initial hospitalization. They are being followed up for 24 months postinjury. Study patients are compared with the general population by using census information, population survey data, and published norms. Characteristics of patients undergoing limb salvage versus amputation are also compared. RESULTS: Most patients were male (77 percent), white (72 percent), and between the ages of twenty and forty-five years (71 percent). Seventy percent graduated from high school (compared with 86 percent nationally) (p < 0.05). One fourth lived in households with incomes below the federal poverty line, compared with 16 percent nationally (p < 0.05). The percentage with no health insurance (38 percent) was also higher than in the general population (20 percent) (p < .05). The percentage of heavy drinkers was over two times higher than reported nationally (p < 0.01). Study patients were slightly more neurotic and extroverted and less open to new experiences. When patient characteristics were compared for those undergoing amputation versus limb salvage, no significant differences were found among any of the variables (p > 0.05). CONCLUSION: In conclusion, LEAP patients differ in important ways from the general population. However, the decision to amputate verus reconstruct does not appear to be significantly influenced by patient characteristics.

Outcome validation of the AO/OTA fracture classification system.

OBJECTIVES: To determine whether a greater severity of injury as documented by the AO/OTA code would correlate with poor scores of impairment, functional performance, and self-reported health status. DESIGN: Prospective, functional outcome. SETTING: Three Level One Trauma Centers. PATIENTS/PARTICIPANTS: Two hundred patients with unilateral and isolated lower extremity fractures. MAIN OUTCOME MEASUREMENTS: Six- and twelve-month SIP, AMA impairment, and functional performance measures of self-selected walking speed, stair climbing, heel raises, rising from a chair, balance work. RESULTS: At six months post injury, overall impairment was significantly (p < 0.05) higher for patients with Type C versus Type B fractures. A significant difference was found among the A, B, C types and the ROM impairment rating at six months (p = 0.004). Using the Scheffe method, the significant difference was determined to be between the B- and C-type fractures. Overall functional performance scores at six months were shown to have significant (p = 0.01) variation using an ANOVA with the significant variation being between the B and C type. At twelve months, the overall functional performance was significant (p = 0.05). CONCLUSION: Patients with C-type fractures had significantly worse functional performance and impairment compared with patients with B-type fractures but were not significantly different from patients with A-type fractures. AO/OTA code may not be a good predictor of six- and twelve-month functional performance and impairment for patients with isolated unilateral lower extremity fractures.

Tibial pilon fractures: a comparison of treatment methods.

OBJECTIVE: This retrospective review of surgically treated distal tibia fractures was undertaken to determine whether treatment with open reduction and internal fixation (ORIF) was more efficacious in achieving fracture union than one of two external fixation methods. METHODS: Of the 60 study patients with pilon fractures, 21 patients were treated with an ankle-spanning half-pin external fixator, 15 patients with a single-ring hybrid external fixator, and 24 patients with ORIF. The severity of injuries was similar across groups. RESULTS: There was no significant difference in complication rates between groups, although two below-knee amputations were required in the ORIF group. A greater (p = 0.03) number of malunions occurred in the fractures treated with external fixation when compared with those treated with ORIF. Fractures in the external fixator groups showed this significant tendency to lose their initial adequate reduction, independent of bone grafting or fibula fixation. There was no significant difference between groups in the need for bone grafting. There was a trend for patients treated with a single ring hybrid frame to require late bone grafting for metaphyseal-diaphyseal nonunion. CONCLUSION: External fixation offers advantages in the treatment of the soft-tissue injury associated with pilon fractures, but malunion continues to be a problem with this method of fixation.

Analysis of the structural behavior of the pelvis during lateral impact using the finite element method.

In this study, three-dimensional finite element models were created from computer tomography data to study lateral impact fractures of the pelvis. The models reflect the complex geometry and material properties of the pelvis. The models were compared to published experimental results for validation. Dynamic analyses of the pelvic structure were performed for different peak forces in the range of 5520 to 15550 N to correspond to the velocities and impulses of real world accidents. The locations of structurally significant regions of the pelvis were identified based upon the stress distribution and upon the energy stored by the pelvis to failure. The impact force which induced fracture of the pelvic bone was 8610 N. The region which failed first in left lateral impact was the right pubic ramus. The fracture pattern was a variant of the lateral compression pelvic injury. The results suggest that the anterior structures of the pelvis are the most sensitive regions. The energy absorbed by the pelvis prior to failure was 8.98 J. The finite element method may be used to determine the strength and energy-absorbing capability of the pelvis for lateral impact loading.

Efficacy of routine preoperative computed tomography scans in colon cancer.

A retrospective review of 180 patients who underwent surgery for primary colon carcinoma from August 1989 to August 1994 was performed to evaluate the necessity of preoperative CT scans in patients with known colon cancer. Sixty-seven patients had preoperative CT scans. Data were collected to evaluate the ability of the scan to detect hepatic metastases, lymph node involvement, and incidental findings that would possibly alter the planned surgical approach. In this study, CT had a sensitivity and specificity of 75 per cent and 88 per cent, respectively, in detecting hepatic metastases. Only 19 per cent of patients with lymph node involvement were correctly staged with CT scans as having lymphadenopathy. Only 3 of 67 patients had incidental findings on CT scans that ultimately changed the surgical approach. It is apparent that because CT scans detect only 75 per cent of hepatic and 19 per cent of hepatic and lymph node involvement and does not seem to alter the planned approach, it is not justified for routine preoperative evaluation of all patients. We, therefore, recommend a more selective approach to patients suspected of having advanced disease if the surgeon suspects that the information may alter the surgical approach.

Return to work following injury: the role of economic, social, and job-related factors.

OBJECTIVES: This study examined factors influencing return to work (RTW) following severe fracture to a lower extremity. METHODS: This prospective cohort study followed 312 individuals treated for a lower extremity fracture at 3 level-1 trauma centers. Kaplan-Meier estimates of the proportion of RTW were computed, and a Cox proportional hazards model was used to examine the contribution of multiple risk factors on RTW. RESULTS: Cumulative proportions of RTW at 3, 6, 9, and 12 months post-injury were 0.26, 0.49, 0.60, and 0.72. After accounting for the extent of impairment, characteristics of the patient that correlated with higher rates of RTW included younger age, higher education, higher income, the presence of strong social support, and employment in a white-collar job that was not physically demanding. Receipt of disability compensation had a strong negative effect on RTW. CONCLUSIONS: Despite relatively high rates of recovery, one quarter of persons with lower extremity fractures did not return to work by the end of 1 year. The analysis points to subgroups of individuals who are at high risk of delayed RTW, with implications for interventions at the patient, employer, and policy levels.

Correlation between the measures of impairment, according to the modified system of the American Medical Association, and function.

We performed a prospective study of 302 patients who had a fracture of the lower extremity. Our purpose was to determine whether there was any association between impairment ratings of the lower extremity, derived with use of the Guides to the Evaluation of Permanent Impairment by the American Medical Association, and measurements of task performance based on direct observation as well as the patient's own assessment of activity limitation and disability as recorded on the Sickness Impact Profile. The mean residual impairment of the lower extremity according to the Guides was 27 per cent one year after the injury. Only 130 subjects (43 per cent) could perform all five functional tasks without difficulty. Eighty-four subjects (28 per cent) reported functional limitations that resulted in a score on the Sickness Impact Profile that was more than one standard deviation from the preinjury norm for the sample. Impairment ratings according to a modification of the system of the American Medical Association correlated strongly with the performance of functional tasks (r = 0.57) as well as the patients' reported activity limitations as recorded on the Sickness Impact Profile (r = 0.55). Correlations were highest when measures of impairment were based on strength rather than on range of motion. The relationship between the impairment rating and function (as observed by an examiner and as reported by the patient) was not influenced by the location of the fracture or the receipt of disability compensation. Our results suggest that the American Medical Association developed a valid approach for the measurement of physical impairment after a fracture of the lower extremity. In our study, the anatomical approach of evaluation based on muscle strength that was described in the Guides to the Evaluation of Permanent Impairment was the most sensitive measure of impairment compared with the anatomical measure based on range of motion and compared with the functional and diagnostic methods for the rating of impairment. Until the diagnostic and functional approaches for the measurement of musculoskeletal impairment are refined, we recommend use of the anatomical approach when evaluating impairment after a fracture of the lower extremity.

Testing promoter activity in the trypanosome genome: isolation of a metacyclic-type VSG promoter, and unexpected insights into RNA polymerase II transcription.

In trypanosomes, most genes are arranged in polycistronic transcription units. Individual mRNAs are generated by 5'-trans splicing and 3' polyadenylation. Remarkably, no regulation of RNA polymerase II transcription has been detected although many RNAs are differentially expressed during kinetoplastid life cycles. Demonstration of specific class II promoters is complicated by the difficulty in distinguishing between genuine promoter activity and stimulation of trans splicing. Using vectors that were designed to allow the detection of low promoter activities in a transcriptionally silent chromosomal context, we isolated a novel trypanosome RNA polymerase I promoter. We were however unable to detect class II promoter activity in any tested DNA fragment. We also integrated genes which were preceded by a T3 promoter into the genome of cells expressing bacteriophage T3 polymerase: surprisingly, transcription was alpha-amanitin sensitive. One possible interpretation of these results is that in trypanosomes, RNA polymerase II initiation is favored by genomic accessibility and double-strand melting.

Opinions of dental consultants on the standard of referral letters in dentistry.

AIM: To ascertain the views of dental consultants on the relative importance of a range of topics relevant to specialist referral. SUBJECTS: 200 randomly selected dental consultants working in the UK in 1995. MAIN OUTCOME MEASURES: Data items which referral letters should contain; standard of referral letters; appropriate reasons for referral; how referrals could be improved; should restrictions be placed on specialist referrals. RESULTS: 161 replies were received. Overall there was only slight variation between specialities with regard to data items, appropriateness of referral and standard of referral letter. The perceived standard of referral letters was adequate or better on 76% of occasions; 21% were deemed to be of a poor standard; 2% were described as appalling. CONCLUSIONS: A Section 63 course on how to refer competently could be of benefit. Consultants were generally not in favour of restricting referrals to them.

Operative treatment of fractures of the tibial plafond. A randomized, prospective study.

We performed a randomized, prospective study to compare the results of two methods for the operative fixation of fractures of the tibial plafond. Surgeons were assigned to a group on the basis of the operation that they preferred (randomized-surgeon design). In the first group, which consisted of eighteen patients, open reduction and internal fixation of both the tibia and the fibula was performed through two separate incisions. An additional patient, who had an intact fibula, had fixation of the tibia only through an anteromedial incision. The second group consisted of twenty patients who were managed with external fixation with or without limited internal fixation (a fibular plate or tibial interfragmentary screws). Ten (26 per cent) of the thirty-nine fractures were open, and seventeen (44 per cent) were type III according to the classification of Rüedi and Allgöwer. There were fifteen operative complications in seven patients who had been managed with open reduction and internal fixation and four complications in four patients who had been managed with external fixation. All but four of the complications were infection or dehiscence of the wound that had developed within four months after the initial operation. The complications after open reduction and internal fixation tended to be more severe, and amputation was eventually done in three patients in this group. At a minimum of two years postoperatively (average, thirty-nine months; range, twenty-five to fifty-one months), the average clinical score was lower for the patients who had had a type-II or III fracture, regardless of the type of treatment. With the numbers available, no significant difference was found between the average clinical scores for the two groups. All of the patients, in both groups, who had had a type-II or III fracture had some degree of osteoarthrosis on plain radiographs at the time of the latest follow-up. With the numbers available, there was no significant difference between the two groups with regard to the osteoarthrotic changes. We concluded that external fixation is a satisfactory method of treatment for fractures of the tibial plafond and is associated with fewer complications than internal fixation.

Bacterial osteomyelitis in adults: evolving considerations in diagnosis and treatment.

Bacterial osteomyelitis causes substantial morbidity worldwide, despite continued progress toward understanding its pathophysiology and optimal management. The approach to osteomyelitis depends upon the route by which bacteria gained access to bone, bacterial virulence, local and systemic host immune factors, and patient age. While imaging studies and nonspecific blood tests may suggest the diagnosis, an invasive technique is generally required to identify the causative pathogens. Given the paucity of comparative clinical trials, antibacterial regimen selection has been largely guided by knowledge of the relative activities and pharmacokinetics of individual drugs, supported by data from animal models. Definitive therapy often requires a combined medical and surgical approach. Newer microvascular and distraction osteogenesis techniques and the use of laser doppler allow more complete surgical resection of infected material while maintaining function. Despite recent advances, many patients with osteomyelitis fail aggressive medical and surgical therapy. More accurate diagnostic methods, better ways to assess and monitor the effectiveness of therapy, and novel approaches to eradicate sequestered bacteria are needed.

Long-term outcomes after lower extremity trauma.

Previous studies have shown that over one-quarter of patients who were working before a severe lower extremity fracture had not returned to work by 12 months after injury. Disabilities also persisted in household management, recreation, and social interaction. The objective of this study was to determine whether recovery extended beyond 12 months. Three hundred nineteen patients who were previously working and were treated at three level I trauma centers for a severe lower extremity fracture were prospectively followed at 3, 6, and 12 months after injury. Patients were queried at each follow-up about their work status and completed the Sickness Impact Profile (SIP) at 6 and 12 months. The SIP is a widely used and well validated measure of general health status; it was used in this study to measure functional recovery across several domains of daily living. Patients who had not recovered by 12 months (i.e., 204 who were not working, working with limitations, or had limitations in performing other daily activities as measured by elevated scores on the SIP) were contacted again at 30 months and asked to complete an interview and the SIP. At 30 months, an estimated 82% of the study patients had returned to work (compared to 72% at 12 months). SIP scores improved only slightly from 6.4 at 12 months to 5.7 at 30 months. At 30 months, 64% of the patients had no disability (SIP scores less than 4), 17% had mild disability (SIP scores of 4 to 9), 12% had moderate disability (SIP scores of 10 to 19), and 7% had severe disability (SIP scores of 20 or higher). Although the majority of patients with persistent disabilities at 30 months had residual physical impairments at 12 months, the extent of impairment did not fully explain why some people had and had not recovered at 30 months after injury. The results confirm those of other studies that conclude that overall, outcomes after serious trauma are good when appropriate trauma and rehabilitation care are rendered. However, a minority of patients still report limitations at 30 months after injury, with one-fifth not returning to work.