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Biomedical subjects

D Steward

Publications and source records attributed to D Steward.

At least 19 recordsLinked to original sources
PubMed2005

A comparison between portable ultrasound (MIDUS) and nocturnal RigiScan when confirming the diagnosis of vascular organic erectile disorder.

In recent years, the use of RigiScan and ultrasound to assess erectile dysfunction has fallen from favour. However, in a small minority of specialist cases, where a vascular, neurogenic or psychogenic aetiology requires confirmation, there remains a need for further investigation. To establish if in a preliminary assessment the use of nocturnal RigiScan or male impotence diagnostic ultrasound system (MIDUS) represents best practice as a diagnostic investigation in patients with a history suggestive of vascular organic erectile disorder. Men attending both urological and psychosexual therapy clinics with erectile dysfunction were assessed using a generic assessment schedule. Patients with a history suggestive of vascular erectile disorder were offered the opportunity of dual investigation of their condition. After screening using a provocative RigiScan using visual stimuli that gleaned inconclusive results, patients were offered the chance to enter a study with both nocturnal RigiScan and MIDUS investigation. These were confined for the purposes of this study to RigiScan events, peak systolic flow velocity (PSV) and end-diastolic flow velocity (EDV) from ultrasound examination where an abnormal EDV is defined as in excess of 4.5 cm/s and a normal PSV is variously defined as being greater than 35 cm/s. In all, 38/43 (88%, 95% CI: 76-95%) of men had a nocturnal event exceeding 3 min on the RigiScan investigation. This compares with 17/43 (40%, 95% CI: 26-54%) of men with a normal EDV blood flow of less than 4.5 cm/s (P<0.017) and 32/43 (74%, CI: 60-85%) of men with a normal PSV flow greater than 35 cm/s (NS). Rigiscan and ultrasonography of the cavernosal vessels are of equal usefulness in suspected arterial penile disease although where veno-occlusive disease is suspected, ultrasonography is more specific.

Adult↗
PubMed2001

Does vibration offer any advantage over visual stimulation studies (VSS) in the assessment of erectile capacity?

The purpose of this work was to determine whether vibration stimulation or erotic videotape material can provide an acceptable diagnostic yield for patients with erectile dysfunction (ED) without the patient needing to endure more explicit erotic films, which may be distasteful to some patients, or intracavernous injections, to which there may be a high inhibitory response. Ninety-five subjects were randomly exposed to either vibration or videotape alone and erectile response monitored by the RigiScan. Where no clinical response was recorded by the RigiScan or by self-report by the patient, both stimuli were presented to the subject. Forty-nine subjects received vibration first and 46 received videotape first. Use of clinically based standardised measures revealed neither group achieving above threshold responses to the first stimulation and there were no differences between the two groups. Eight subjects (8%) between both groups exceeded the tip threshold during combination stimulation. Single stimulation with vibration or erotic videotape with provocative RigiScan monitoring is unhelpful in the assessment of ED in any of the diagnostic subgroups of ED. In comparison to previous provocative studies, combination of stimuli sets, whilst increasing penile response (circumferential change and rigidity) did not lead to significant evidence of clinically relevant responses using current RigiScan measures or patient self-report of change. Further studies are necessary to determine the most useful set of stimuli for provocation studies with the RigiScan.

Erectile Dysfunction↗
PubMed1999

Can we assess utility using the patient's own words?

Current methods of utility assessment enable systematic elicitation of patient values in support of medical treatment decision making where interventions involve tradeoffs. Until now, utility assessment protocols have generally employed health care providers' rather than patients' terminology. This study evaluates the feasibility of a protocol that extends traditional methods by using the patient's own words. Fifteen dialysis patients were interviewed with the protocol to elicit individualized multidimensional quality of life (IMQOL) models representing their values. The IMQOL models were then used to assess two modes of dialysis, each with and without complications, as well as the patient's current health. Interview completion rate was 88.2%. Of those completing the interviews, 80% said that they would want the results used to guide decision making in the event of mental incapacity. 53% said the IMQOL model represented their values as well as or better than did traditional utility assessment results.

Adult↗
PubMed1998

Qualification of discordant responses in utility assessment.

In many studies of utility assessment, the discordant response rate is significantly high. Discordant responses suggest inconsistency and, in turn, suggest inaccurate measurement of personal values that can lead to erroneous medical recommendations. The most common method of dealing with these responses is to exclude them from the sample statistics as incoherent or confused respondents. This paper proposes another perspective on discordant responses. In a recent study eliciting utility values for states of health that follow stroke, we observed a high rate of discordant responses. Closer examination of these discordant responses reveals that discordant responses are not all alike. Simple qualitative and quantitative views of these differences suggest that there may be information outside the concordant population of responses, which is lost by their exclusion. In an effort to understand the elevated discordant response rate, the effect of relaxing the defining boundaries of a discordant response was explored.

Adult↗
PubMed1997

Prognostic indicators for squamous cell carcinoma of the oral cavity: a clinicopathologic correlation.

Fifty-three patients with T1 squamous cell cancer of the floor of mouth and ventral surface of the tongue with a known clinical outcome were retrospectively analyzed and arbitrarily divided into "aggressive" and "nonaggressive" groups based on their clinical behavior. Various host and tumor factors were then evaluated in an attempt to determine whether the tumor behavior could have been predicted. The paraffin-embedded tumor specimens were evaluated for tumor differentiation, tumor thickness and tumor invasion, microvessel density, and p53 expression. In addition, a composite morphologic grading score was obtained by combining cell differentiation, nuclear polymorphism, mitosis activity, depth of infiltration, type of infiltration, and lymphatic infiltration. No single technique appeared capable of identifying "aggressive" behavior, although possibly an evaluation of composite factors might show promise in the future.

Carcinoma, Squamous Cell↗
PubMed1996

What is computer-aided diagnosis?

A review of computer aided diagnostic principles is presented. A brief treatise on the definition and theory of the utilization of machines to aid human diagnostic reasoning forms a foundation for its practical use in current veterinary practice. Understanding a tool is the key to its proper use. Therefore, the intentions of the currently available software are discussed as well as the limitations. Finally, in light of the refined understanding of the use of computers to aid diagnosis, the scope of appropriate use is outlined as an encouragement to make the most of the tool.

Animals↗
PubMed1996

The clinician computer.

Information has always brought questions as it brought knowledge. It follows that the current age of accelerated change creates the opportunity for more questions to rise up in a shorter amount of time than ever before. Rather than be overwhelmed, the reader is asked to step back to categorically consider the clinical process in simple familiar terms of input and output; to consider the nature of the information veterinarian clinicians deal with on a daily basis. It is by taking a mechanistic view of the human contribution that we gain clarity in our understanding of what it is we do. The more we understand the unique roles we play, the better job we do at using machines to allow us to keep our service more human as clinicians.

Animals↗
PubMed1990

Halothane hepatitis in children.

Halothane hepatitis is now a well-recognized distinct entity in adults, but there prevails an often-taught "axiom" that halothane hepatitis "does not occur" in children. We describe 2 children who developed cholestatic hepatitis following halothane anesthesia. The first patient had no antecedent liver disease, and presented with anorexia, abdominal pain and delayed onset of jaundice after multiple halothane exposures. Halothane-specific antibodies were positive, and liver tests resolved completely. The second patient had antecedent liver disease and presented with delayed onset of unexplained high fevers for 10 days following a single halothane exposure. Gradually increasing cholestasis ensued in the absence of other causes of liver disease. Halothane antibodies were negative. These cases illustrate different clinical presentations of halothane hepatitis, such as delayed onset of jaundice or fever following halothane exposure. The difficulties in making a definitive diagnosis and the need to exclude other causes of liver disease are detailed. Risk factors and other presentations are discussed. While halothane hepatitis appears to be an uncommon entity in children, it does occur, and may present with manifestations less than fulminant hepatic failure. A high index of suspicion and a detailed history of the time sequence of events are necessary as the diagnosis is primarily clinical. Halothane-specific antibodies are helpful if positive. In any child developing unexplained jaundice or high fevers following halothane anesthesia, further exposures should be avoided and halothane-specific antibodies obtained.

Chemical and Drug Induced Liver Injury↗
PubMed1987

Direct, standardized assessment of clinical competence.

Doctor ratings of clerkship performance are often discounted as not accurately reflecting clinical competence. Such ratings are influenced by the following uncontrolled variables: case difficulty; differing rater focus and standards; lack of agreement on what constitutes acceptable performance; and collective patient care responsibility masks individual contributions. Standardized direct measures of clinical competence were developed to control these factors and allow direct comparisons of student performance. Students saw 18 patients representing frequently occurring and important patient problems. Student actions and decisions were recorded and subsequent responses to questions revealed knowledge of pathophysiology, basis for actions, use and interpretation of laboratory investigations, and management. Actions and responses were graded using a pre-set key. The examination covered 73% of designated clinical competencies. Examinations scores corresponded with independent measures of clinical competence. Reliability studies indicated that new cases can be substituted in subsequent years with confidence that scores will maintain similar meaning. Costs are +6.95 per student per case, which is modest considering the quality and quantity of information acquired. Methods described are practical for evaluation of clerks and residents and for licensing and specialty certification examinations.

Clinical Clerkship↗
PubMed1986

Results of inpatient pediatric resuscitation.

We retrospectively reviewed the results of 42 cardiopulmonary arrests occurring over 1 yr in the general ward of a pediatric hospital. These data were compared to those of a similar study done 10 yr previously in the same institution. Patients were divided into those having pure respiratory arrest and those who also had cardiac arrest. In the most recent series, overall 6-month survival was 17%; however, only 9% of the cardiac arrest patients survived. Ten years previously, the survival rate from cardiac arrest was 11%. In both series, pure respiratory arrest had a significantly better outcome than cardiopulmonary arrest, and predictors of nonsurvival were a duration of arrest greater than 15 min and the administration of more than one iv bolus of epinephrine. During the more recent series, sepsis and upper airway problems produced fewer arrests. There was one neurologically damaged survivor in each study period. Our study confirms that the outcome of pediatric cardiac arrest is poor when arrest occurs in the hospital.

Adolescent↗