PubMed Health⌕ Search

Biomedical subjects

David W Roberson

Publications and source records attributed to David W Roberson.

16 recordsLinked to original sources
PubMed2007

Using a virtual reality temporal bone simulator to assess otolaryngology trainees.

OBJECTIVE: The objective of this study is to determine the feasibility of computerized evaluation of resident performance using hand motion analysis on a virtual reality temporal bone (VR TB) simulator. We hypothesized that both computerized analysis and expert ratings would discriminate the performance of novices from experienced trainees. We also hypothesized that performance on the virtual reality temporal bone simulator (VR TB) would differentiate based on previous drilling experience. STUDY DESIGN: The authors conducted a randomized, blind assessment study. METHODS: Nineteen volunteers from the Otolaryngology-Head and Neck Surgery training program at the University of Toronto drilled both a cadaveric TB and a simulated VR TB. Expert reviewers were asked to assess operative readiness of the trainee based on a blind video review of their performance. Computerized hand motion analysis of each participant's performance was conducted. RESULTS: Expert raters were able to discriminate novices from experienced trainees (P < .05) on cadaveric temporal bones, and there was a trend toward discrimination on VR TB performance. Hand motion analysis showed that experienced trainees had better movement economy than novices (P < .05) on the VR TB. CONCLUSION: Performance, as measured by hand motion analysis on the VR TB simulator, reflects trainees' previous drilling experience. This study suggests that otolaryngology trainees could accomplish initial temporal bone training on a VR TB simulator, which can provide feedback to the trainee, and may reduce the need for constant faculty supervision and evaluation.

Cadaver↗
PubMed2006

The histone deacetylase inhibitor sodium butyrate protects against cisplatin-induced hearing loss in guinea pigs.

OBJECTIVE: There is a need for otoprotective agents that can be administered systemically without compromising cancer treatment. Histone deacetylase inhibitors are anticancer agents that act by upregulating the expression of cell-cycle control genes. They are also neuroprotective, leading us to hypothesize that they might be otoprotective. The goal of this study was to determine if the antitumor agent sodium butyrate (a histone deacetylase inhibitor) protects against cisplatin ototoxicity when administered systemically. STUDY DESIGN: This was an animal study. METHODS: : Cisplatin was administered to guinea pigs who received either 12 days of sodium butyrate (7 d before and 5 d after cisplatin) or equivolume saline injections. Hearing was tested with distortion product otoacoustic emission (DPOAE) analysis before the start of the study and 2 weeks after cisplatin treatment. RESULTS: Guinea pigs given a single intraperitoneal injection of 14 mg/kg cisplatin experience a mean hearing loss of 8 dB across the frequencies of 3.5, 5, 7, 10, 14, and 20 kHz. Intraperitoneal injection of 1.2 mg/kg sodium butyrate per day for 7 days before and 5 days after cisplatin almost completely eliminates this threshold shift (P=.0011). CONCLUSIONS: The histone deacetylase inhibitor sodium butyrate gives almost complete protection in a single-dose model of cisplatin ototoxicity in guinea pigs. Because histone deacetylase inhibitors are anticancer agents with very few side effects, they may be candidates for clinical use during cisplatin chemotherapy.

Animals↗
PubMed2006

Otolaryngologists' responses to errors and adverse events.

OBJECTIVES: The objectives of this study were to describe otolaryngologists' emotional reactions to errors and adverse events, their efforts to take responsibility, and their attempts to implement improvements. STUDY DESIGN AND METHODS: A retrospective, anonymous survey of 2,500 U.S. otolaryngologists who were members of the American Academy of Otolaryngology-Head and Neck Surgery about errors in their practice was conducted. Respondents were asked whether an error had occurred in their practice in the past 6 months and, if so, to describe the error, its consequences, and any corrective actions taken. Two aspects of these reports stood out, which were beyond the scope of the original study: the respondents' emotional responses and their corrective actions. RESULTS: The response rate was 18.6%. Two hundred ten (45%) respondents reported a total of 212 analyzable error reports and 230 corrective actions. Corrective actions included disclosure to the patient (20 [9%]), ameliorating the consequences of the event to the patient (107 [50%]), personal practice changes (14 [7%]), improvements in the respondent's practice or department (60 [28%]), and hospitalwide or broader corrective actions (19 [9%]). Emotional reactions to errors and adverse events were reported by 22 (10%) otolaryngologists, including regret, embarrassment, guilt, anxiety, loss of temper, and irritation. Legal action was mentioned by five physicians (2%). CONCLUSIONS: Otolaryngologists took actions not only to treat their patients, but also to improve patient care in their practice, department, hospital, or community. Emotional reactions to errors and adverse events are common and need to be addressed in medical training and practice.

Attitude of Health Personnel↗
PubMed2006

Errors and adverse events in otolaryngology.

PURPOSE OF REVIEW: The study of errors in medicine has proliferated in the past few years. This spark was ignited by the Institute of Medicine's report in 2000, titled 'To Err is Human'. Studies of errors have been performed in both medical and surgical specialties. Surgical skill and technology has proliferated over the last century to such an extent that outcomes will probably not improve from focusing finite resources on attempts to enhance surgical skill or developing new instrumentation. Advancing medicine in the 21 Century will probably depend on our ability to address and ameliorate errors and adverse events in healthcare. Directing attention to this previously little studied realm of medicine has the ability to dramatically reduce morbidity and mortality. Small changes have the ability to result in outcomes that are far beyond what is predicted by incremental measures. RECENT FINDINGS: There have been studies identifying and classifying errors in otolaryngology in out-patient and in-hospital settings, addressing allergy sera misadministration, providing quality assurance for pathology reports in head and neck malignancies, implementing computerized patient records, and detailing problems that occur when patients have a test ordered and the results are not followed up. SUMMARY: The study of errors in medicine is going to dramatically increase in the next decade. The practicing otolaryngologist must be vigilant for errors, use surgical time-outs, should have a system in place to track tests ordered and results received, and most importantly have the capability to identify and ameliorate errors as they occur on an individual and institutional level.

Humans↗
PubMed2005

Teaching emergency airway management using medical simulation: a pilot program.

OBJECTIVE: Simulation is a tool that has been used successfully in many high performance fields to permit training in rare and hazardous events. Our goal was to develop and evaluate a program to teach airway crisis management to otolaryngology trainees using medical simulation. METHODS: A full-day curriculum in the management of airway emergencies was developed. The program consists of three airway emergency scenarios, developed in collaboration between attending otolaryngologists and faculty from the Center for Medical Simulation. Following each scenario, the participants are led in a structured, video-assisted debriefing by a trained debriefer. Didactic material on team leadership and crisis management is built into the debriefings. Pediatric otolaryngology fellows, residents, and medical students have participated in the four courses that have been held to date. Participants evaluated the program on a five-point Likert scale. RESULTS: A total of 17 trainees participated in four pilot training courses. The survey data are as follows: overall program, 5.0 (SD, 0.00); course goals, 4.79 (SD, 0.43); realism, 4.36 (SD, 0.63); value of lecture, 4.71 (SD, 0.47); and quality of debriefings, 4.92 (SD, 0.28). Sample comments include: "This is a valuable tool for students and residents since true emergencies in ORL are often life-threatening and infrequent," and "This is a great course-really all physicians should experience it." Overall evaluation was extremely positive and both residents and fellows described the course as filling an important void in their education. CONCLUSION: Medical simulation can be an extremely effective method for teaching airway crisis management and teamwork skills to otolaryngology trainees at all levels.

Airway Obstruction↗
PubMed2005

Pediatric deaths due to otolaryngologic causes: a population-based study in Massachusetts, 1990-2002.

OBJECTIVE: To identify the most common otolaryngologic causes of mortality in the 0 to 19 age group in the state of Massachusetts and to estimate the pediatric otolaryngologic mortality rate based on population data. STUDY DESIGN: Population-based retrospective cohort study. METHODS: The Massachusetts State Registry of Vital Records and Statistics electronic database was searched for all otolaryngology related causes of death from 1990 to 2002 for children aged 0 to 19. The individual death certificates were then reviewed, and a database of otolaryngology related pediatric deaths was created. RESULTS: A total of 59 otolaryngology related deaths were identified in the pediatric population from 1990 to 2002. Eighty-one percent of deaths occurred because of airway compromise caused by infection, anatomic obstruction, or congenital anomaly. The remaining 19% of deaths occurred because of aspiration, nonairway infections, and malignant neoplasms. Ninety-five percent of deaths in the children under age 10 were caused by airway compromise. Six of seven deaths (86%) in the age 15 to 19 group occurred because of malignant neoplasms. The overall mortality rate caused by otolaryngologic causes was estimated to be 0.28 per 100,000 population. CONCLUSIONS: The overall mortality rate for otolaryngology related deaths is low in the pediatric population. The vast majority of deaths are caused by airway compromise, primarily because of laryngotracheobronchitis or other upper airway obstruction. In older children (ages 15-19), malignant head and neck neoplasms are the leading cause of otolaryngology related deaths.

Adolescent↗
PubMed2005

Development and validation of an objective instrument to measure surgical performance at tonsillectomy.

OBJECTIVES: The goals of this project were 1) to develop and validate an objective instrument to measure surgical performance at tonsillectomy, 2) to assess its interobserver and interobservation reliability and construct validity, and 3) to select those items with best reliability and most independent information to design a simplified form suitable for routine use in otolaryngology surgical evaluation. DESIGN: Prospective, observational data collection for an educational quality improvement project. METHODS: The evaluation instrument was based on previous instruments developed in general surgery with input from attending otolaryngologic surgeons and experts in medical education. It was pilot tested and subjected to iterative improvements. After the instrument was finalized, a total of 55 tonsillectomies were observed and scored during academic year 2002 to 2003: 45 cases by residents at different points during their rotation, 5 by fellows, and 5 by faculty. Results were assessed for interobserver reliability, interobservation reliability, and construct validity. Factor analysis was used to identify items with independent information. RESULTS: Interobserver and interobservation reliability was high. On technical items, faculty substantially outperformed fellows, who in turn outperformed residents (P < .0001 for both comparisons). On the "global" scale (overall assessment), residents improved an average of 1 full point (on a 5 point scale) during a 3 month rotation (P = .01). In the subscale of "patient care," results were less clear cut: fellows outperformed residents, who in turn outperformed faculty, but only the fellows to faculty comparison was statistically significant (P = .04), and residents did not clearly improve over time (P = .36). Factor analysis demonstrated that technical items and patient care items factor separately and thus represent separate skill domains in surgery. CONCLUSIONS: It is possible to objectively measure surgical skill at tonsillectomy with high reliability and good construct validity. Factor analysis demonstrated that patient care is a distinct domain in surgical skill. Although the interobserver reliability for some patient care items reached statistical significance, it was not high enough for "high stakes testing" purposes. Using reliability and factor analysis results, we propose a simplified instrument for use in evaluating trainees in otolaryngologic surgery.

Clinical Competence↗
PubMed2004

Direct transdifferentiation gives rise to the earliest new hair cells in regenerating avian auditory epithelium.

The avian auditory epithelium is capable of complete regeneration after hair cell (HC) loss. Most new HCs arise via cell division, but approximately one-third of new HCs arise via direct transdifferentiation (DT), in which supporting cells (SCs) alter their phenotype without dividing. In this study, we used synchronous, gentamicin-induced near-total HC loss in the basal end of the epithelium and continuous infusion of the cell division marker bromodeoxyuridine (BrdU) to identify the origin of each individual regenerating HC. Early new HCs were identified by immunolabeling for the HC-specific marker myosin-VIIa, and mitotic cells with BrdU immunolabeling. The first new HCs arising via DT appear 72-96 hr after gentamicin, 24-48 hr earlier than the first new mitotic HCs. After Day 6, however, most new HCs are mitotic. The "intermediate" morphology that has been suggested to be characteristic of DT is seen in HCs arising via both pathways. These findings suggest that DT is a simpler, more rapid process that produces the first new HCs, and that mitotic regeneration is somewhat slower but ultimately produces most new HCs. The identical morphology of regenerating HCs from both pathways suggests that once HC fate is established, all new HCs follow similar cellular processes during differentiation and reorganization into the regenerated epithelium.

Animals↗
PubMed2004

Can history and physical examination reliably diagnose pediatric obstructive sleep apnea/hypopnea syndrome? A systematic review of the literature.

OBJECTIVE: Using an evidence-based technique, systematically review the literature to evaluate the accuracy of routine clinical history and physical examination in the diagnosis of obstructive sleep apnea/hypopnea syndrome (OSAHS) in the pediatric patient. STUDY DESIGN AND SETTING: The biomedical literature was systematically reviewed. Articles comparing the results of clinical evaluation to polysomnography (PSG) were selected. The level of evidence was assessed using established evidence-based medicine (EBM) guidelines. RESULTS: Twelve articles were identified using the search criteria. Eleven of 12 articles concluded that clinical evaluation is inaccurate in the diagnosis of OSAHS. The level of evidence was good to very good (Grade B/B+). CONCLUSION/SIGNIFICANCE: Clinical history and physical examination are not reliable for diagnosing OSAHS compared with overnight PSG. Complicating the interpretation of this work is the lack of a validated PSG threshold of clinically significant disease. There is an urgent need for the development of adequate screening tests with validated clinical outcomes. EBM RATING: B-3.

Adolescent↗
PubMed2004

Epiglottitis in the Hemophilus influenzae type B vaccine era: changing trends.

OBJECTIVE: To describe the epidemiology, natural history, and treatment of epiglottitis in the Hemophilus influenzae type B (Hib) vaccine era. DESIGN: Ten-year retrospective study. SETTING: Tertiary-care children's hospital. PATIENTS: Nineteen patients with a discharge diagnosis of epiglottitis. INTERVENTION: As indicated by the presentation of the patient, including direct laryngoscopy, intubation, intravenous antibiotics, and steroids. MAIN OUTCOME MEASURES: Presentation, management, and microbiology. RESULTS: Presenting symptoms included fever, drooling, and hot potato voice. Patients' ages ranged from 15.8 months to 17.5 (mean 8.9) years. From 1992 to 1997, the mean age was 5.8 years; from 1998 to 2002, the mean age was 11.6 years. Sixty-eight percent of patients were transferred from an outside hospital. A lateral neck radiograph was recorded in 84% of patients. Mean leukocyte count was 16600. Direct laryngoscopy with intubation was performed in 79%; intubation was for an average of 3.5 days. H. influenzae was cultured in six patients, five of which had up-to-date immunizations. The most commonly administered antibiotics were ampicillin/sulbactam and ceftriaxone. Steroids were administered to 63% of patients. Complications included deep neck space infection (2), seizure (1), recurrent illness (1), and vocal granuloma (1). There were no deaths. CONCLUSION: The demographics, causative organisms, and natural history of epiglottitis have changed substantially in the Hib vaccination era. The clinician evaluating and treating patients with epiglottitis should be aware of current trends.

Adolescent↗
PubMed2004

Classification and consequences of errors in otolaryngology.

OBJECTIVE: To develop a preliminary classification system for errors in otolaryngology. METHODS: A retrospective, anonymous survey was distributed to 2,500 members of the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS). Respondents were asked whether an error had occurred in their practice in the last 6 months, and if so, to describe the error, its consequences, and any corrective action taken. RESULTS: There were 466 (18.6%) responses. Two hundred ten (45% of respondents) otolaryngologists reported 216 errors. A classification system for errors in otolaryngology was developed. Errors were classified as related to history and physical (1.4%), differential or final diagnosis (1.4%), testing (10.4%), surgical planning (9.9%), wrong-site surgery (6.1%), anesthesia-related (3.3%), wrong drug/dilution on the surgical field (3.8%), technical (19.3%), retained foreign body (0.9%), equipment-related (9.4%), postoperative care (8.5%), medical management (13.7%), nursing/ancillary (0.5%), administrative (6.6%), communication (3.8%), and miscellaneous (0.9%). There were 78 cases of major morbidity and 9 deaths. If these data are representative, there may be more than 2,600 episodes of major morbidity and more than 165 deaths related to medical error in otolaryngology patients annually. CONCLUSIONS: Human error in otolaryngology occurs in all practice components, including diagnostic, treatment, surgical, communication, and administrative. Types of errors reported by otolaryngologists differ from those reported by other specialists. Error classification systems may need to reflect each specialty's realm of practice. Errors in otolaryngology cause appreciable morbidity and mortality. Quantitative study of errors and the development of targeted prevention and amelioration strategies should be a high priority.

Adolescent↗
PubMed2004

Quality and safety in a complex world: why systems science matters to otolaryngologists.

Almost all modern medical care is delivered in the setting of many overlapping systems. Each system may consist of multiple providers and in most cases electronic and mechanical components. Even "simple" outpatient care is delivered by teams of providers, administrators, and devices. Critically ill inpatients are cared for in extraordinarily complex systems with hundreds of human and non-human elements. The science of complex systems has exploded in recent decades, and there is a large body of knowledge about how such systems function effectively or ineffectively. Many principles of systems science are simple to understand and apply, but few Otolaryngologists are well educated about them. A basic knowledge of systems science will greatly improve the Otolaryngologist's ability to function in complex health care systems and to provide the best care for his or her patients.

Humans↗
PubMed2003

Caspase inhibitors promote vestibular hair cell survival and function after aminoglycoside treatment in vivo.

The sensory hair cells of the inner ear undergo apoptosis after acoustic trauma or aminoglycoside antibiotic treatment, causing permanent auditory and vestibular deficits in humans. Previous studies have demonstrated a role for caspase activation in hair cell death and ototoxic injury that can be reduced by concurrent treatment with caspase inhibitors in vitro. In this study, we examined the protective effects of caspase inhibition on hair cell death in vivo after systemic injections of aminoglycosides. In one series of experiments, chickens were implanted with osmotic pumps that administrated the pan-caspase inhibitor z-Val-Ala-Asp(Ome)-fluoromethylketone (zVAD) into inner ear fluids. One day after the surgery, the animals received a 5 d course of treatment with streptomycin, a vestibulotoxic aminoglycoside. Direct infusion of zVAD into the vestibule significantly increased hair cell survival after streptomycin treatment. A second series of experiments determined whether rescued hair cells could function as sensory receptors. Animals treated with streptomycin displayed vestibular system impairment as measured by a greatly reduced vestibulo-ocular response (VOR). In contrast, animals that received concurrent systemic administration of zVAD with streptomycin had both significantly greater hair cell survival and significantly increased VOR responses, as compared with animals treated with streptomycin alone. These findings suggest that inhibiting the activation of caspases promotes the survival of hair cells and protects against vestibular function deficits after aminoglycoside treatment.

Amino Acid Chloromethyl Ketones↗
PubMed2002

The role of mitomycin in the prevention and treatment of scar formation in the pediatric aerodigestive tract: friend or foe?

OBJECTIVE: To evaluate the role of mitomycin in the prevention and treatment of scar formation in the pediatric aerodigestive tract. DESIGN: Prospective study; institutional review board-approved clinical trial. SETTING: Tertiary care pediatric medical center. PATIENTS: Fifteen patients; choanal atresia in 5 patients, airway stenosis in 8 patients, hypopharyngeal stenosis in 1 patient, and esophageal stenosis in 1 patient. OUTCOME: The efficacy and safety of mitomycin in the prevention of scar formation. INTERVENTION: All patients underwent surgical repair of the stenotic area, followed by topical application of mitomycin (1 mL of 0.4 mg/mL) for 4 minutes. RESULTS: Ten patients (67%) showed major improvement, 4 patients (27%) showed minor improvement, and 1 patient (7%) showed no improvement. CONCLUSION: Topical application of mitomycin can play an effective role in the prevention and treatment of scar formation in the aerodigestive tract.

Administration, Topical↗
PubMed2002

REST mRNA expression in normal and regenerating avian auditory epithelium.

Hair cells (HCs) and supporting cells (SCs) in the auditory epithelium initially arise from a sheet of undifferentiated cells. Although much has been learned about the initial steps leading to the fate determination of HCs and SCs, respectively, little is known about what molecular events 'finalize' cell fate determination. We investigated the role of repressor element-1 (RE-1) silencing transcription factor (REST), whose inactivation is known to be a requirement for a cell to assume a neuronal identity. Here we show by in situ hybridization (ISH) that SCs express REST messenger RNA (mRNA) but sensory HCs lack detectable expression. Using a more sensitive reverse transcription-polymerase chain reaction assay, however, we detected the presence of a neuron-specific splice variant in the epithelium, suggesting that HCs express REST mRNA at levels too low to be detectable by ISH. In regenerating auditory epithelium, we found that REST mRNA was expressed and upregulated in all remaining cells in the damaged region of the epithelium, consistent with its expression pattern during development prior to neurogenesis. Surprisingly, REST mRNA was also upregulated in SCs in the apical, undamaged region of the epithelium, and readily detectable by ISH in the HCs in this region. This finding suggests that the grossly undamaged region of the epithelium is in fact biochemically altered towards a 'less developed' state. Our results indicate that REST inactivation is an important step in finalizing HC fate in the chick inner ear.

Animals↗