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Biomedical subjects

G O'Brien

Publications and source records attributed to G O'Brien.

At least 19 recordsLinked to original sources
PubMed1998

Effect of lung volume reduction surgery on diaphragm strength.

Since lung volume reduction surgery (LVRS) reduces end-expiratory lung volume, we hypothesized that it may improve diaphragm strength. We evaluated 37 patients for pulmonary rehabilitation and LVRS. Before and 8 wk after pulmonary rehabilitation, 24 patients had spirometry, lung volumes, diffusion capacity, incremental symptom limited maximum exercise test, 6-min walk test, maximal static inspiratory and expiratory mouth pressures, and transdiaphragmatic pressures during maximum static inspiratory efforts and bilateral supramaximal electrophrenic twitch stimulation measured. Twenty patients (including 7 patients who crossed over after completing pulmonary rehabilitation) had baseline measurements postrehabilitation, and 3 mo post-LVRS. Patients were 58 +/- 8 yr of age, with severe COPD and hyperinflation (FEV1, 0.69 +/- 0.21 L; RV, 4.7 +/- 1.4 L). Nineteen patients had bilateral LVRS performed via median sternotomy and stapling, and 1 patient had unilateral LVRS via thorascopy with stapling. After rehabilitation, spirometry and DL(CO)/VA were not different, and lung volumes showed a slight worsening in hyperinflation. Gas exchange, 6-min walk distance, maximum oxygen uptake (VO2max), and breathing pattern during maximum exercise did not change after rehabilitation, but total exercise time was significantly longer. Inspiratory muscle strength (PImax, Pdi(max combined), Pdi(max sniff), Pdi(max), Pdi(twitch)), was unchanged after rehabilitation. In contrast, after LVRS, FVC increased 21%, FEV1 increased 34%, TLC decreased 13%, FRC decreased 23%, and FRC(trapped gas) and RV decreased by 57 and 28%, respectively. PCO2 was lower (44 +/- 6 versus 48 +/- 6 mm Hg, p < 0.003) and 6-min walk distance increased (343 +/- 79 versus 250 +/- 89 m, p < 0.001), as did total exercise time during maximum exercise (9.2 +/- 1.9 versus 6.9 +/- 2.7 min, p < 0.01). Minute ventilation (29 +/- 8 versus 21 +/- 6 L/min, p < 0.001) and tidal volume (1.0 +/- 0.33 versus 0.84 +/- 0.25 L, p < 0.001) during maximum exercise increased whereas respiratory rate was lower (28 +/- 6 versus 32 +/- 7 breaths/min, p < 0.02). Measurements of respiratory muscle strength (PImax, 74 +/- 28 versus 50 +/- 18 cm H2O, p < 0.002; Pdi(max combined), 80 +/- 25 versus 56 +/- 29 cm H2O, p < 0.01; Pdi(max sniff), 71 +/- 7 versus 46 +/- 27 cm H2O, p < 0.01; Pdi(twitch), 15 +/- 5 versus 7 +/- 5 cm H2O, p < 0.01) were all greater post-LVRS. Inspiratory muscle workload as measured by Pdi TTI was lower following LVRS (0.07 +/- 0.02 versus 0.09 +/- 0.03, p < 0.03). On multiple regression analysis, increases in PImax correlated significantly with decreases in RV and FRC(trapped gas) after LVRS (r = 0.67, p < 0.03). We conclude that LVRS significantly improves diaphragm strength that is associated with a reduction in lung volumes and an improvement in exercise performance. Future studies are needed to determine the relationship and stability of these changes over time.

Diaphragm↗
PubMed1998

Telephone call reminders and attendance in an adolescent clinic.

OBJECTIVE: To determine the effect of a single telephone call reminder on appointment compliance among adolescents in an inner city, hospital-based clinic. METHODS: A randomized clinical trial was conducted at the Adolescent Clinic, a part of the Ambulatory Pediatric Practice Clinic in Cleveland, Ohio, from December 1995 to November 1996. A total of 703 routine adolescent ambulatory appointments were randomized to receive either a single telephone call reminder 1 day before the appointment or to receive no reminder. A single telephone call attempt was directed primarily to the parent or guardian of the patient in the assignment group. If not available, the reminder message was left with the patient or other family member, or on the answering machine. The study variables selected included age, gender, appointment time, distance from clinic, and payment source, and for the intervention group, the recipient of the reminder telephone call. The outcome measure was the attendance rate. RESULTS: The intervention group (n = 347) and control group (n = 356) were well balanced for all study variables. The overall attendance rate was 49.8%. Only 204 (58.8%) of the 347 attempted intervention appointments were contacted successfully by telephone. In the attempted intervention analysis, the attendance rate of 55.6% in the intervention group (n = 347), regardless of whether subjects were successfully contacted by telephone, was 26.1% greater than the 44.1% attendance rate in the control group. In the completed intervention analysis, the attendance rate of 65.2% in the successfully contacted individuals within the intervention group (n = 204) was increased by 47.8% over that in the control group. In the univariate analysis, attendance for self-paying patients (25.4%) was worse than that for any group. In the logistic regression analysis, both the reminder telephone call intervention and the payment source were independent predictors of attendance. In the group that was called successfully (n = 204), there was no association between attendance and the recipient of the telephone call. CONCLUSIONS: Telephone reminders are a very effective method of increasing attendance in a hospital-based adolescent clinic. The reminder is a consistently effective intervention whether the message is delivered to the patient, to the parent or other family member, or to a telephone answering machine. Adolescent patients whose visits are not covered by Medicaid or commercial insurance are least likely to attend their clinic appointments, and a telephone call reminder has no effect on this pattern.

Adolescent↗
PubMed1997

Is there a comorbid relationship between hyperactivity and emotional psychopathology?

Some of the early literature implied that emotional disorders were almost incompatible with hyperactivity in childhood. The paper addresses this issue using a large epidemiological data base--of two cohorts of 7- & 8-year-old and 11- & 12-year-old children from the North of England. There are two themes, first, the paper reports on the prevalence of emotional symptoms and disorder among hyperactive children. Second, it explores co-occurrence of hyperactivity and emotional psychopathology according to whether the hyperactivity is situational or pervasive and according to the age of the child. Hyperactivity proved to have an association with emotional symptoms and disorder at both ages but the links with disorder were most prominent among the older children. Among our high risk or maladjusted samples the strongest links were with home-based situational hyperactivity. However, among the general population cohort, emotional disorder proved to be a function of pervasiveness of hyperactivity and older age.

Attention Deficit Disorder with Hyperactivity↗
PubMed1997

Learning disability and epilepsy. 2, a review of available outcome measures and position statement on development priorities.

People with epilepsy plus learning disabilities pose a challenge in terms of clinical management and research investigation, and, to date, the measurement of outcomes in this population has been limited. There have been uncertainties concerning both the 'what' and the 'how' of assessment. This paper presents a comprehensive review of available outcome measures across nine domains, i.e. relating to seizures, drugs, cognitive function, behaviour, social functioning, carer functioning, attitudes, motivation and 'quality of life'. This last domain reflects more global measures designed to encompass several assessment strands. The uses and limitations of each scale is discussed and, where data are available, psychometric properties are also presented. The paper concludes with suggestions for the further development of outcome measures in this population.

Epilepsy↗
PubMed1997

Learning disabilities: moving forward--a focus on epilepsy, Birmingham, England, 29 June 1996.

On 29 June 1996 a conference was held in Birmingham to highlight the status of epilepsy in people with learning disabilities. The conference consisted both of seminars and workshops. Dr Tim Betts, Birmingham; Dr Greg O'Brien, Northumberland; and Dr Mike Kerr addressed issues of assessment, diagnosis and drug treatment of epilepsy in this population. This meeting report summarizes the proceedings of the conference.

Anticonvulsants↗
PubMed1997

Stability of improvements in exercise performance and quality of life following bilateral lung volume reduction surgery in severe COPD.

STUDY OBJECTIVE: To evaluate the long-term stability of improvements in exercise capacity and quality of life (QOL) after lung volume reduction surgery (LVRS). DESIGN: Case-series analysis. SETTING: University hospital. PATIENTS: Twenty-six patients with severe airflow obstruction (mean FEV1 of 0.67+/-0.18 L) and moderate to severe hyperinflation (mean total lung capacity of 7.30+/-1.90 L). INTERVENTION AND MEASUREMENTS: All patients underwent bilateral LVRS via median sternotomy. Serial measurement of lung function, symptom-limited cardiopulmonary exercise tests, 6-min walk distances (6MWD), and sickness impact profile (SIP) scores were done before, and at 3, 6, 12, and 18 months after surgery. RESULTS: FEV1 (0.93+/-0.29 vs 0.68+/-0.19 L, p<0.001) increased while residual volume (3.47+/-1.2 vs 4.77+/-1.5 L, p<0.001) decreased significantly at 3 months post-LVRS compared to baseline, and these changes were maintained at 12 to 18 months follow-up. Similarly, the increase in 6MWD at 3 months post-LVRS (340+/-84 vs 251+/-114 m, p<0.001) was sustained at all follow-up times. On cardiopulmonary exercise testing, total exercise time (9.0+/-1.8 vs 6.1+/-1.9 min, p<0.001), oxygen uptake at peak exercise (VO2 peak) (14.9+/-4 vs 11.9+/-3 mL/kg/min, p<0.001), maximum oxygen pulse (7.43+/-2.37 vs 5.85+/-1.96 mL/beat, p<0.005), and maximum minute ventilation (VEmax) (30.3+/-10 vs 23.5+/-7.1 L/min, p<0.001) increased significantly at 3 months post-LVRS. On serial study following LVRS, total exercise time remained significantly greater at 6 (8.5+/-1.38 min) and 12 months (8.71+/-2.0 min) post-LVRS compared to baseline (5.81+/-1.9 min, p<0.05). VO2 peak tended to be higher at all follow-up periods (3 months, 16.1+/-4.3; 6 months, 14.5+/-2.6; 12 months, 14.1+/-3.5 mL/kg) compared to baseline (12.6+/-3.9 mL/kg, p=0.08). Similarly, maximum O2 pulse tended to be higher in all follow-up studies (3 months, 8.45+/-2.7; 6 months, 7.6+/-1.7; 12 months, 7.42+/-2.1 mL/beat) compared to baseline (6.39+/-2.5 mL/beat, p=0.06). Higher VEmax continued to be observed at 6 (30+/-10 L/min) and 12 months (28+/-10 L/min) post-LVRS, compared to baseline (23+/-7 L/min, p=0.02). VEmax post-LVRS was significantly higher at 3 and 6 months compared to baseline on post-hoc analysis (p<0.05). Overall SIP scores were lower at 3 months (7 vs 18, p<0.0002) post-LVRS and were sustained in long-term follow-up. CONCLUSION: We conclude that bilateral LVRS via median sternotomy in selected patients with severe, diffuse emphysema improves exercise performance and QOL at 3 months following LVRS and these improvements are maintained for at least 12 to 18 months in follow-up.

Airway Obstruction↗
PubMed1996

Lung volume reduction surgery in ventilator-dependent COPD patients.

BACKGROUND: Lung volume reduction surgery has been advocated recently as adjunctive surgical therapy to improve lung and chest wall mechanics in selected patients with diffuse emphysema. Although clear-cut guidelines to select candidates have not been fully established, patients decompensated with significant pulmonary artery hypertension and hypercapnic respiratory failure are currently not considered suitable subjects. Accordingly, ventilator-dependent COPD patients are not considered candidates for this procedure. However, because ventilator-dependent COPD patients have an exceptionally poor prognosis, we elected to offer them this promising, but unproved surgical intervention. Herein, we describe the outcome of these three patients. PATIENTS: The 3 patients had recurrent exacerbations of COPD precipitating respiratory failure, and following aggressive medical therapy remained mechanically ventilated for 11 to 16 weeks (1 patient had a brief period of successful weaning before returning to mechanical ventilation). Prior to surgery, the patients had severe hypercapnia and cor pulmonale. Compared with preoperative values, surgery resulted in improvements in PaO2/FIO2, 304 +/- 80 (SD) vs 229 +/- 48 mm Hg, reductions in PaCO2, 44 +/- 3 vs 60 +/- 9 mm Hg, increases in FVC, 1.63 + 0.52 vs 1.09 +/- 0.05 L, and maximum inspiratory pressure, 57 +/- 22 vs 29 +/- 12 cm H2O. Postoperative complications included persistent air leaks and one tension pneumothorax. Patients weaned from mechanical ventilation after 10 to 21 days all were discharged home and they continue to demonstrate improved gas exchange and functional status. CONCLUSIONS: Lung volume reduction surgery in select, ventilator-dependent COPD patients can result in improved gas exchange and respiratory mechanics that enable successful weaning and overall improved functional status.

Female↗
PubMed1995

Hyperactivity: prevalence and relationship with conduct disorder.

This paper reports the prevalence of situational and pervasive hyperactivity using different definitions of 'caseness', and explores the relationship between situational and pervasive hyperactivity and conduct disorder, using a large data base from the North of England. The prevalence of hyperactivity, and its relationship with conduct disorder, varied according to whether hyperactivity was pervasive or situational, according to the age of the child and to the definition of hyperactivity 'caseness'. Among younger children only, school based situational and pervasive hyperactivity had comparable comorbidity with other available evidence of psychiatric disorder and hyperactivity was virtually a prerequisite for conduct disorder. Among older children, pervasive hyperactivity had greater comorbidity with other psychiatric disorder than situational hyperactivity and, furthermore, displayed the strongest links with conduct disorder.

Attention Deficit Disorder with Hyperactivity↗
PubMed1992

Nicotine elimination and tolerance in non-dependent cigarette smokers.

Although most smokers are nicotine-dependent, recent studies suggest that some very light smokers ("chippers", who smoke fewer than five cigarettes per day) may smoke for decades without developing dependence. It was considered that slowed nicotine elimination and/or reduced nicotine tolerance might underlie chippers' ability to maintain smoking at such low levels. To evaluate this hypothesis, we studied the elimination kinetics and pharmacodynamics of nicotine in chippers and matched regular smokers. Plasma nicotine levels and cardiovascular responses were observed for several hours after subjects were administered uniform doses of tobacco smoke. Chippers did show less chronic nicotine tolerance, but only on some response measures. Their rates of nicotine elimination equaled those of regular smokers. This finding, when coupled with other data about chippers' smoking patterns and nicotine absorption, establish that chippers cannot maintain substantial plasma nicotine levels between cigarettes, and thus suggest that attempts to maintain minimal trough levels of nicotine do not underlie chippers' smoking.

Adult↗
PubMed1991

Excessive follicular recruitment and growth in mothers of spontaneous dizygotic twins.

We wished to establish the frequency, regularity and laterality of multiple ovulation in mothers of dizygotic (DZ) twins and controls. Subjects had regular menses and were not using oral contraceptives. Ovarian ultrasound scans were taken over a number of cycles in 21 mothers of DZ twins and 18 controls (including 13 mothers of monozygotic [MZ] twins). Multiple large follicles (greater than or equal to 12 mm diameter) were seen significantly more frequently in mothers of DZ twins (13/21 mothers, 24/77 cycles, average +/- SE follicles/cycle 1.34 +/- 0.11) than controls (2/18 mothers, 3/31 cycles, average 1.10 +/- 0.08). Both ipsilateral and contralateral multiple follicles were observed. In one case a mother of DZ twins showed multiple large follicles in 7 out of 10 cycles in which she was scanned, including both ipsi- and contralateral patterns of occurrence.

Adult↗
PubMed1990

A psychiatric study of deviant eating behaviour among mentally handicapped adults.

A study of deviant eating behaviour among mentally handicapped adults in community placements is reported. Those individuals with a psychiatric disorder showed more deviant eating behaviour. Depressed subjects, in particular, showed an excess of the amount eaten and time spent searching for food, as well as the tendency to eat all sweet food presented to them. Non-food pica was uncommon, even among the autistic subjects.

Adult↗
PubMed1989

Repeat self-harm: an 18-month follow-up.

An 18-month follow-up of cases of deliberate self-harm (DSH) revealed that 30% had repeated the act. Of a large number of items recorded at index DSH only one, a past history of self-harm, was associated with repetition. It is suggested that some factors not predictive of longer term repeat DSH may be important in the assessment of risk for immediate further self-harm.

Female↗
PubMed1989

Pneumomediastinum secondary to a mandible fracture.

Pneumomediastinum may be produced by a simple facial fracture. It may also be a sign of other aerodigestive tract injuries, and this possibility should be ruled out. A minimal patient workup should include panendoscopy and soft tissue neck x-ray films in all cases. If no other injuries are found, resolution of the pneumomediastinum may be expected without further treatment.

Adult↗
PubMed1988

The dexamethasone suppression test in bulimia nervosa.

In a study of the dexamethasone suppression test (DST) in patients with bulimia nervosa, a non-suppression rate of about 50% was found. The only clinical correlates of DST non-suppression were a previous history of weight loss and/or of anorexia nervosa. These results suggest that DST non-suppression in these subjects may be a trait rather than a state marker of anorexia nervosa.

Adult↗