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Biomedical subjects

P J Sullivan

Publications and source records attributed to P J Sullivan.

At least 19 recordsLinked to original sources
PubMed2003

Retrospective analysis of evidence base for tests used in diagnosis and monitoring of disease in respiratory medicine.

OBJECTIVES: To determine how many common clinical tests used in a respiratory medicine outpatient clinic are based on high quality evidence. DESIGN: Retrospective review of case notes. Record of first three tests for each patient. Diagnostic tests, tests used to assess existing condition, explicit trials of therapy were included. Literature search for supporting evidence and grading of best evidence for each test. SETTING: Inner city university teaching hospital in the United Kingdom. PARTICIPANTS: All new outpatients referred to a single respiratory medicine team over a period of three months. MAIN OUTCOME MEASURES: Proportion of tests supported by level 1a-1c evidence (scale developed by Centre for Evidence Based Medicine). RESULTS: Only half the tests that were used to make or exclude a diagnosis and a fifth of the tests used to assess a known condition were supported by level 1a-1c evidence. There was no evidence to support trials of therapy. CONCLUSIONS: A large proportion of clinical tests in respiratory medicine are not supported by level 1a-1c evidence. None of the therapeutic trials that were used were supported by evidence.

Diagnostic Techniques, Respiratory System↗
PubMed2000

Platelet dynamics following allergen challenge in allergic asthmatics.

BACKGROUND: There is evidence that platelet activation occurs in allergic inflammation and asthma, but little is known about the role platelets play in airway inflammation associated with asthma. OBJECTIVES: In the present study, we have investigated the kinetics of platelet activation following allergen provocation of allergic asthmatics to determine the dynamics of platelet activation relative to changes in lung function and changes in airway inflammation. METHODS: Changes in platelet count and haematocrit from baseline were measured during the early asthmatic response (EAR), late asthmatic response (LAR; or at corresponding time points) and at 24 h were compared between allergen- and saline-challenged groups. A subgroup of allergen-challenged asthmatics, a group of 7 challenged asthmatics and 7 controls were bronchoscoped, and BAL fluid was collected and analysed for levels of histamine and eosinophil cationic protein. RESULTS: There was a fall in circulating platelet count, but not haematocrit after allergen challenge when compared with saline during the LAR or at 24 h. At 24 h FEV(1) had returned to within 20% of baseline in all subjects, although the thrombocytopaenia and airway inflammation persisted. CONCLUSIONS: Our results suggest that persistent thrombocytopaenia accompanies allergen exposure and persists beyond changes in airway obstruction at a time when airway inflammation is present. Our results provide further evidence that platelets may be involved in allergic disease.

Adolescent↗
PubMed1999

Risk factors for post-carotid endarterectomy hematoma formation.

PURPOSE: To identify risk factors for post-carotid endarterectomy (CEA) hematoma formation and establish the incidence of this complication at The Ottawa Hospital - Civic Campus (TOH-CC). METHODS: A chart review of all patients who underwent CEA at TOH-CC from January 1, 1996 to December 31, 1997 was completed. Identified cases of post-CEA wound hematoma were entered into a case-control study using age and sex-matched controls from within the cohort. These matched pairs were assessed for 31 potential risk factors including demographic details, co-existing medical conditions, preoperative medications, intraoperative management, and postoperative parameters. Risk factors associated with post-CEA hematoma with P<0.05 were entered into a backward step-wise logistic regression model for multivariate analysis. RESULTS: Charts from 249 patients were reviewed and 29 cases of post-carotid endarterectomy hematoma were identified (12% incidence). Six of the initial 31 potential risk factors emerged as univariate predictors of post-CEA hematoma formation (P<0.05): general anesthesia, carotid shunt placement, intraoperative hypotension, non-reversal of heparin, neurosurgery service, and preoperative aspirin use. Following logistic regression only non-reversal of heparin, intraoperative hypotension, and carotid shunt placement were identified as multivariate predictors of post-CEA hematoma formation. More time was spent in critical care settings (ICU/PACU) (P<0.01) and there was increased perioperative mortality (P = 0.04) within the hematoma group. CONCLUSIONS: Post-CEA hematoma formation is associated with increased morbidity and mortality. Non-reversal of heparin, intraoperative hypotension, and carotid shunt placement are multi-variate predictors of post-CEA hematoma formation.

Aged↗
PubMed1997

The effect of a novel orally active selective PDE4 isoenzyme inhibitor (CDP840) on allergen-induced responses in asthmatic subjects.

Recent studies have suggested that theophylline, a nonspecific phospho-diesterase inhibitor, has useful anti-inflammatory actions in asthma. Phosphodiesterase 4 (PDE4) represents the predominant PDE isoenzyme present in inflammatory cells. PDE4 inhibitors might, therefore, have beneficial effects in asthma. Side-effects, specifically nausea, have limited the use of existing agents. CDP840 is an orally active, potent and selective PDE4 inhibitor. We have examined the effect of CDP840 on the allergen-induced asthmatic response, its possible modes of action, and its tolerability at therapeutic doses. A total of 54 patients were recruited to three double-blind, placebo-controlled studies. The first study examined the effect of CDP840 (15 mg b.i.d. for 9.5 days) on the allergen-induced asthmatic response in patients with known dual response to allergen. A second study examined the effect of CDP840 (15 mg b.i.d. for 9.5 days) on airway responsiveness to histamine. A third study examined whether single dose CDP840 (15 and 30 mg) had significant bronchodilatory effects. In all studies, CDP840 was well-tolerated, with no patients reporting nausea. CDP840 did not lead to changes in baseline forced expiratory volume in one second (FEV1) as compared to placebo. The late asthmatic response (LAR) to allergen, expressed as area under the curve at 3-8 h (AUC3-8h), was inhibited by 30% (p=0.016), an effect which persisted to the end of the observation period. The early asthmatic response (EAR) was unaffected, and there was no bronchodilatory effect at the doses used. Treatment with CDP840 did not affect bronchial hyperresponsiveness to histamine. In conclusion, CDP840 significantly attenuated the late asthmatic response to allergen challenge in the absence of any bronchodilatory or histamine antagonist effect. This suggests that CDP840 may exert its effects via an anti-inflammatory mechanism.

Adolescent↗
PubMed1993

Occupational stress in psychiatric nursing.

Psychiatric nursing is invariably assumed to be a stressful area of nursing practice. Empirical evidence to support this proposition is limited, however, due to the lack of research in this field. The purpose of this project was to examine occupational stress in a specified area of psychiatric nursing. The research was exploratory and therefore the concern was discovery and description rather than the testing of clear hypotheses and the development of causal relationships. The study has four main objectives. First, to describe the various stressors present in the work of the psychiatric nurse in the acute admission wards of two district health authorities. Secondly, to measure the effects of stress using a recognized and well-validated instrument for recording levels of burnout. Thirdly, through the use of a particular theoretical framework to identify the types of coping strategy used by the participants in the study. Fourthly, to note any clear associations between the stressors, the effects of stress and the ways of coping identified in the study. The conceptual basis for the project was Lazarus's cognitive theory of stress and coping and Maslach's model of burnout.

Adaptation, Psychological↗
PubMed1993

The genes encoding the secreted aspartyl proteinases of Candida albicans constitute a family with at least three members.

The secreted aspartyl proteinase activity from Candida albicans is thought to be a potential virulence factor. Four laboratories have cloned a gene from C. albicans encoding this enzyme. When two of these genes sharing 77% homology at the DNA level are hybridized under conditions of high stringency to contour-clamped homogeneous electric field chromosome separations of four different strains, they label different chromosomes: chromosome 6 for SAP1 and chromosome R for SAP2. The existence of different genes for the two sequences was confirmed by polymerase chain reaction. Genomic Southern blots probed with the genes and washed at low stringency revealed several cross-hybridizing bands. Contour-clamped homogeneous electric field chromosome separations probed at low stringency indicated that there was a cross-hybridizing sequence on chromosome 3 in addition to those on chromosomes R and 6. The genes for the secreted aspartyl proteinase activity in C. albicans thus constitute a gene family which we have called the SAP family.

Aspartic Acid Endopeptidases↗
PubMed1992

A comparison of transcutaneous end-tidal and arterial measurements of carbon dioxide during general anaesthesia.

A randomized, prospective study was performed to evaluate the accuracy of a new transcutaneous carbon dioxide (CO2) monitor (Fastrac) during general anaesthesia. Twenty-two adult patients undergoing elective surgery were subjected to three different levels of minute ventilation by varying their respiratory rates in a randomized cross-over design. Simultaneous measurements of transcutaneous CO2 (PTCCO2) and arterial CO2 (PaCO2) were obtained at three levels of minute ventilation (low, medium and high). End-tidal CO2 (PETCO2) values were also recorded from a mass spectrometer (SARA) at each time period. A total of 66 data sets with PaCO2 ranging from 28-62 mmHg were analyzed. The PTCCO2 values demonstrated a high degree of correlation with PaCO2 over the range of minute ventilation (y = 0.904x + 6.36, r = 0.92, P less than 0.001). The PETCO2 measurement also demonstrated a generally good correlation with PaCO2 (y = 0.62x + 9.21, r = 0.89, and P less than 0.01). However, the PETCO2-PaCO2 gradients (mean 7.0 +/- 3.1 mmHg) were greater than the PTCCO2-PaCO2 gradients (mean 2.3 +/- 2.4 mmHg) at all three levels of minute ventilation (P less than 0.05). These differences were greatest when PaCO2 was in the high range (48-60 mmHg). We conclude that the new Fastrac CO2 monitor is accurate for monitoring carbon dioxide levels during general anaesthesia. The new transcutaneous devices provide an effective method for non-invasive monitoring of CO2 in situations where continuous, precise control of CO2 levels is desired.

Adult↗
PubMed1992

Temperature and humidity within the clothing microenvironment.

The present study investigates clothing microenvironment conditions that may develop during prolonged exposure of workers to a hot environment. Five subjects were exposed to a linear increase in ambient temperature from 20-40 degrees C over a 90-min period, and then remained at 40 degrees C for an additional 90 min. During the exposures, subjects were clad in four types of helicopter personnel suits (Gore-Tex, Cotton Ventile, Nomex/Insulite, and Nomex/Neoprene), incorporating both dry-suit and wet-suit designs. Continuous assessment was made of skin temperature, rectal temperature, and of microenvironment temperature, relative humidity, and vapor pressure (T mu, RH mu, and VP mu) 8 mm from the surface of the skin. Results indicate that although microenvironment temperatures were similar among suits and slightly lower than that of the environment, the RH mu and VP mu were much greater than those of the ambient air. The Nomex/Insulite and Nomex/Neoprene suits showed the highest VP mu, of which only the Nomex/Insulite resulted in significantly greater increases in rectal temperature, likely due to complete covering of the body with the impermeable insulite component. The present study demonstrates the need to discern between the ambient conditions and the conditions encountered next to the skin when protective clothing is worn.

Adult↗
PubMed1991

Pyloric stenosis.

Infantile pyloric stenosis is the most frequently encountered infant gastrointestinal obstruction in most general hospitals. Although the primary therapy for pyloric stenosis is surgical, it is essential to realize that pyloric stenosis is a medical and not a surgical emergency. Preoperative preparation is the primary factor contributing to the low perioperative complication rates and the necessity to recognize fluid and electrolyte imbalance is the key to successful anaesthetic management. Careful preoperative therapy to correct severe deficits may require several days to ensure safe anaesthesia and surgery. The anaesthetic records of 100 infants with pyloric stenosis were reviewed. Eighty-five per cent of the infants were male (i.e., 5.7:1 male to female ratio) 12% were prematures. Surgical correction was undertaken at an average age of 5.6 wk, and the average weight of the infants at the time of surgery was 4 kg. A clinical diagnosis of pyloric stenosis by history and physical examination alone was made in 73% of the infants presenting to The Hospital for Sick Children. All the infants received general anaesthesia for the surgical procedure and there were no perioperative deaths.

Anesthesia↗
PubMed1988

Assessment of inflammatory bowel disease activity by technetium 99m phagocyte scanning.

Autologous technetium 99m-labeled phagocyte scanning has been used to assess disease activity in inflammatory bowel disease in 51 consecutive patients. Strong correlations were found between the 24-h fecal excretion of isotope and the histologic score of mucosal biopsy specimens (rS = 0.84, p less than 0.001, where rS is Spearman's rank correlation coefficient), and between the 24-h fecal excretion of isotope and a clinical inflammatory bowel disease activity index based on the Crohn's disease activity index (rS = 0.87, p less than 0.001). To develop a clinically useful and objective measure of inflammatory bowel disease activity that did not require a 24-h stool collection, the intensity of bowel uptake on scanning was graded visually from 0 to 4, a ratio of count rates for the region of interest to the iliac crest reference region was calculated, and the rapidity of labeled phagocyte uptake into inflamed bowel was measured as the peak uptake time. Visual grading of disease activity on the scans was validated by comparing it with the ratio of count rates from inflamed bowel regions of interest and those from the iliac crest reference region. The ratio of count rates showed a significant correlation with the clinical disease activity index (r = 0.75, p less than 0.001). The visual scan grade also correlated well with the clinical activity index (r = 0.87, p less than 0.001). Count rates from hourly scans were also used to calculate the time of peak uptake of counts for a given region of interest. There was a strong negative correlation between this peak uptake time and the fecal excretion of isotope (rS = -0.81, p less than 0.001), a clinical activity index (r = -0.60, p less than 0.001), and the histologic score of the mucosal biopsy specimens (r = -0.84, p less than 0.001). These results indicate that the technetium 99m-labeled phagocyte scan provides an objective assessment of disease activity in inflammatory bowel disease using the visual scan grade, ratio of count rates for the region of inflamed bowel, or by the peak uptake time, thereby avoiding the problems associated with fecal collections. This scanning test may prove to be of significant value in clinical management and in the assessment of treatment response.

Adolescent↗
PubMed1988

A clinical comparison of Technegas and xenon-133 in 50 patients with suspected pulmonary embolus.

A comparison of "Technegas" and xenon-133 was performed in 50 patients presenting with a clinical diagnosis of pulmonary embolus. All patients underwent studies with xenon inhalation, Technegas inhalation, and macroaggregated albumin perfusion. Technegas is a new ultrafine ventilatory agent with a particle size of 50 to 200A produced from technetium pertechnetate and graphite in an argon environment. Although particulate in nature, Technegas is transported and diffuses like a gaseous agent. Its production results in a high specific activity yield with high efficiency. There is no significant deposition in the central airways, and good peripheral visualization of the lung is obtained. The study was designed to assess whether Technegas could be used as a ventilatory agent to obtain high-quality diagnostic images. All studies were reported as in normal clinical practice, and no statistical analysis was performed. The aim of the study was simply to see what role Technegas had in a busy clinical department and how well it reflected ventilation by comparison with xenon. Patient compliance with Technegas was 100 percent and for xenon was 94 percent. Technegas enables one to obtain high-quality ventilatory images and has an important role to play in the assessment of pulmonary ventilation.

Adult↗