ORCID Profile
0000-0001-8864-254X
Current Organisation
Flinders Medical Centre
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Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2010
Publisher: Elsevier BV
Date: 06-1997
Abstract: STUDY OBJECTIVES AND PATIENTS: Pulmonary hypertension (PH) is common in COPD and may predict mortality in this disorder. We have compared the pulmonary vasodilator effects, dose-response characteristics, and tolerability of two calcium channel blockers, amlodipine and extended-release (ER) felodipine, in 10 patients (seven men, age 68+/-4.8 [SD] years) with clinically stable COPD and PH. Drugs were given in equal single daily oral doses (2.5, 5, and 10 mg), increasing weekly for 3 weeks, in a randomized investigator-blinded crossover manner with a 1-week wash-out period between the two treatments. Doppler measurements of pulmonary hemodynamics were made on the seventh day of treatment at each drug dose. Lung function, arterial blood gases, and adverse events were also monitored weekly. A dose-dependent decline of pulmonary artery pressure (PAP) was observed with each drug. A dose of 2.5 mg produced a significant decrease in PAP compared with baseline (20% amlodipine, 17% felodipine ER). Additional decreases in PAP were observed at 5 mg and 10 mg that were similar for both drugs, but did not reach statistical significance compared with 2.5 mg. There was a dose-related decrease in pulmonary vascular resistance and increase in oxygen delivery with amlodipine and felodipine ER. Lung function and blood gas values were stable throughout. Side effects (headache and ankle edema) were less frequent during amlodipine treatment (p or = 2.5 mg, are effective pulmonary vasodilators in COPD patients with PH. Their dose-response characteristics are similar, but amlodipine treatment was associated with fewer side effects.
Publisher: BMJ
Date: 06-1995
DOI: 10.1136/THX.50.6.613
Abstract: This study was undertaken to establish the prevalence of, and the factors contributing towards, sleep disordered breathing in patients with quadriplegia. Forty representative quadriplegic patients (time since injury > 6 months, injury level C8 and above, Frankel category A, B, or C mean (SE) age 35.0 (1.7) years) had home sleep studies in which EEG, EOG, submental EMG, body movement, nasal airflow, respiratory effort, and pulse oximetry (SpO2) were measured. Patients reporting post traumatic amnesia of > 24 hours, drug or alcohol abuse or other major medical illness were excluded from the study. A questionnaire on medications and sleep was administered and supine blood pressure, awake SpO2, spirometric values, height, and neck circumference were measured. A pattern of sustained hypoventilation was not observed in any of the patients. Sleep apnoeas and hypopnoeas were, however, common. Eleven patients (27.5%) had a respiratory disturbance index (RDI, apnoeas plus hypopnoeas per hour of sleep) of > or = 15, with nadir SpO2 ranging from 49% to 95%. Twelve of the 40 (30%) had an apnoea index (AI) of > or = 5 and, of these, nine (75%) had predominantly obstructive apnoeas-that is, > 80% of apnoeas were obstructive or mixed. This represents a prevalence of sleep disordered breathing more than twice that observed in normal populations. For the study population RDI correlated with systolic and diastolic blood pressure and neck circumference. RDI was higher in patients who slept supine compared with those in other postures. Daytime sleepiness was a common complaint in the study population and sleep architecture was considerably disturbed with decreased REM sleep and increased stage 1 non-REM sleep. Sleep disordered breathing is common in quadriplegic patients and sleep disturbance is significant. The predominant type of apnoea is obstructive. As with non-quadriplegic patients with sleep apnoea, sleep disordered breathing in quadriplegics is associated with increased neck circumference and the supine sleep posture.
Publisher: Springer Science and Business Media LLC
Date: 30-03-1998
Abstract: Sleep disordered breathing is common in patients with tetraplegia. Nocturnal arterial hypoxemia and sleep fragmentation due to sleep apnoea may be associated with cognitive dysfunction. We therefore studied the influence of sleep disordered breathing on neuropsychological function in 37 representative tetraplegic patients (mean age 34 +/- 9.7 years). Thirty percent (11 of 37 patients) had clinically significant sleep disordered breathing, defined as apnoea plus hypopnoea index (AHI) greater than 15 per hour of sleep. Most apnoeas were obstructive in type. Seven patients (19%) desaturated to < 80% during the night. Neuropsychological variables were significantly correlated with measures of sleep hypoxia, but not with the AHI and the frequency of sleep arousals. The neuropsychological functions most affected by nocturnal desaturation were: verbal attention and concentration, immediate and short-term memory, cognitive flexibility, internal scanning and working memory. There appeared to be a weak association between the presence of severe sleep hypoxia and visual perception, attention and concentration but no association was found between sleep variables and depression scores. We concluded that sleep disordered breathing is common in patients with tetraplegia and may be accompanied with significant oxygen desaturation. The latter impairs daytime cognitive function in these patients, particularly attention, concentration, memory and learning skills. Cognitive disturbances resulting from sleep apnoea might adversely affect rehabilitation in patients with tetraplegia.
Publisher: Elsevier BV
Date: 1999
Abstract: We compared the validity of a new portable polysomnographic recorder against a laboratory-based polysomnographic system from the same manufacturer. Simultaneous, full polysomnographic recordings from the portable device (PSGP) and the laboratory-based system (PSGL) were obtained using separate sets of sensors on 20 patients referred for investigation of sleep apnea. After initial optimization of signals, the portable device was left unattended in 10 of the patients (to simulate home studies), while in the other 10 the signals were reviewed on a laptop computer screen and adjustments to electrode or sensor placement made as needed during the studies. Recordings were manually scored by a technologist blinded to the origin of the data. The quality of signals was comparable between the PSGP and PSGL studies, apart from a slight decrease in respiratory signal quality during PSGP studies that led to reduced confidence in respiratory event scoring. SaO2 signal loss was also greater in unattended PSGP. There was good agreement between PSGP and PSGL for sleep variables and the apnea-hypopnea index (r=0.99). The periodic limb movement index was slightly lower during unattended PSGP. Blinded physician assessment of the records led to a recommendation for repeat studies due to poor signal quality in one (10%) attended and one (10%) unattended portable recording. There was no significant discordance between PSGP and PSGL in the final diagnostic formulations. Portable polysomnography is a viable alternative to laboratory-based polysomnography and may be improved further by better sensor attachment.
Publisher: American Thoracic Society
Date: 15-01-2002
DOI: 10.1164/AJRCCM.165.2.2010092
Abstract: Daytime pulmonary hypertension (PH) is relatively common in obstructive sleep apnea (OSA) and is thought to be associated with pulmonary vascular remodeling (PRm). The extent to which PH is reversible with treatment is uncertain. To study this, we measured pulmonary hemodynamics (Doppler echocardiography) in 20 patients with OSA (apnea-hypopnea index [AHI] 48.6 +/- 5.2/h, mean +/- SEM) before and after 1 and 4 mo of CPAP treatment (compliance 4.7 +/- 0.5 h/night). Patients had normal lung function, and no cardiac disease or systemic hypertension. Doppler studies were performed at three levels of inspired oxygen concentration (11%, 21%, and 50%) and during incremental increases in pulmonary blood flow (10, 20, and 30 microg/kg/min dobutamine infusions). Treatment resulted in a decrease in pulmonary artery pressure (Ppa, 16.8 +/- 1.2 mm Hg before CPAP versus 13.9 +/- 0.6 mm Hg after 4 mo CPAP, p < 0.05) and total pulmonary vascular resistance (231.1 +/- 19.6 versus 186.4 +/- 12.3 dyn. s. cm(-)(5), p < 0.05). The greatest treatment effects occurred in the five patients who were pulmonary hypertensive at baseline. The pulmonary vascular response to hypoxia decreased after CPAP (DeltaPpa/DeltaSa(O(2)) 10.0 +/- 1.6 mm Hg before versus 6.3 +/- 0.8 mm Hg after 4 mo CPAP, p < 0.05). The curve of Ppa versus cardiac output (Q), derived from the incremental dobutamine infusion, shifted downward in a parallel fashion during treatment. Systemic diastolic blood pressure also fell significantly. Improvements in pulmonary hemodynamics were not attributable to changes in left ventricular diastolic function or Pa (O(2)). We conclude that CPAP treatment reduces Ppa and hypoxic pulmonary vascular reactivity in OSA and speculate that this may be due to improved pulmonary endothelial function.
Publisher: BMJ
Date: 11-2016
Publisher: Elsevier BV
Date: 08-2012
Publisher: American Thoracic Society
Date: 02-1994
DOI: 10.1164/AJRCCM.149.2.8306039
Abstract: To determine whether pulmonary hypertension (PH) can occur in obstructive sleep apnea syndrome (OSAS) in the absence of lung or primary cardiac disease, we studied 27 patients (26 males, mean age 49 +/- 10 yr) with OSAS (respiratory disturbance index [RDI] > 10 events/h) in whom clinically significant lung or cardiac diseases were excluded. Pulsed Doppler measurements of pulmonary hemodynamics, pulmonary function tests, arterial blood gas analysis, and polysomnography were performed. A total of 11 OSAS patients (41%) were found to have pulmonary hypertension. The levels of PH were relatively mild (Ppa < or = 26 mm Hg). There were no differences between PH and non-PH patients in body mass index (BMI), smoking history, or lung function. PH patients were more hypoxemic when awake than non-PH patients (PaO2 = 72.2 +/- 7.6 versus 77.6 +/- 7.3 mm Hg, respectively p < 0.05) but did not differ in severity of sleep apnea (RDI = 51.9 +/- 25.1 versus 56.8 +/- 26.2 events/h, respectively p = NS) or indices of sleep desaturation. The hypoxemia in PH patients could not be explained by impairment of lung function, greater body mass, or a higher prevalence of smoking, and PaO2 in the study population was significantly correlated with Ppa (r = -0.46, p < 0.02) but not with FEV1 or BMI. We conclude that lung disease is not a prerequisite for PH in OSAS.(ABSTRACT TRUNCATED AT 250 WORDS)
Publisher: Elsevier BV
Date: 04-2014
DOI: 10.1016/J.RMED.2013.12.014
Abstract: We evaluated the predictive value of the COPD assessment test (CAT™) for exacerbation in the following six months or time to first exacerbation among COPD patients with previous exacerbations. COPD outpatients with a history of exacerbation from 19 hospitals completed the CAT questionnaire and spirometry over six months. Exacerbation events were prospectively collected using a structured questionnaire. The baseline CAT score categorised into four groups (0-9, 10-19, 20-29, and 30-40) showed strong prediction for time to first exacerbation and modest prediction for any exacerbation or moderate-severe exacerbation (AUC 0.83, 0.64, and 0.63 respectively). In multivariate analyses, the categorised CAT score independently predicted all three outcomes (p = 0.001 or p 24, 14, 9, and 5 weeks and the adjusted RR was 1.00, 1.30, 1.37, and 1.50 in the category of 0-9, 10-19, 20-29, and 30-40 respectively. Exacerbation history (≥2 vs. 1 event in the past year) was related to time to first exacerbation (adjusted HR 1.35 p = 0.023) and any exacerbation during the study period (adjusted RR 1.15 p = 0.016). The results of this study support the use of the CAT as a simple tool to assist in the identification of patients at increased risk of exacerbations. This could facilitate timely and cost-effective implementation of preventive interventions, and improve health resource allocation. Clinicaltrials.gov: NCT01254032.
Publisher: Elsevier BV
Date: 1997
DOI: 10.1378/CHEST.111.1.256-A
Abstract: The learning brain establishes schemas (knowledge structures) that benefit subsequent learning. We investigated how sleep and having a schema might benefit initial learning followed by rearranged and expanded memoranda. We concurrently examined the contributions of sleep spindles and slow-wave sleep to learning outcomes. Fifty-three adolescents were randomly assigned to an 8 h Nap schedule (6.5 h nocturnal sleep with a 90-minute daytime nap) or an 8 h No-Nap, nocturnal-only sleep schedule. The study spanned 14 nights, simulating successive school weeks. We utilized a transitive inference task involving hierarchically ordered faces. Initial learning to set up the schema was followed by rearrangement of the hierarchy (accommodation) and hierarchy expansion (assimilation). The expanded sequence was restudied. Recall of hierarchical knowledge was tested after initial learning and at multiple points for all subsequent phases. As a control, both groups underwent a No-schema condition where the hierarchy was introduced and modified without opportunity to set up a schema. Electroencephalography accompanied the multiple sleep opportunities. There were main effects of Nap schedule and Schema condition evidenced by superior recall of initial learning, reordered and expanded memoranda. Improved recall was consistently associated with higher fast spindle density but not slow-wave measures. This was true for both nocturnal sleep and daytime naps. A sleep schedule incorporating regular nap opportunities compared to one that only had nocturnal sleep benefited building of robust and flexible schemas, facilitating recall of the subsequently rearranged and expanded structured knowledge. These benefits appear to be strongly associated with fast spindles. NCT04044885 (t2/show/NCT04044885).
Publisher: Elsevier BV
Date: 03-2009
DOI: 10.1016/J.PCAD.2008.06.001
Abstract: Obstructive sleep apnea (OSA) is associated with repetitive nocturnal arterial oxygen desaturation and hypercapnia, large intrathoracic negative pressure swings, and acute increases in pulmonary artery pressure. Rodents when exposed to brief, intermittent hypoxia for several hours per day to mimic OSA developed pulmonary vascular remodeling and sustained pulmonary hypertension and right ventricular hypertrophy within a few weeks. Until recently, however, it was unclear whether episodic nocturnal hypoxemia associated with OSA was sufficient to cause similar changes in humans. This controversy appears to have been resolved by several recent studies that have shown (a) pulmonary hypertension in 20% to 40% of patients with OSA in the absence of other known cardiopulmonary disorders and (b) reductions in pulmonary artery pressure in patients with OSA after nocturnal continuous positive airway pressure (CPAP) treatment. The pulmonary hypertension associated with OSA appears to be mild and may be due to a combination of precapillary and postcapillary factors including pulmonary arteriolar remodeling and hyperreactivity to hypoxia and left ventricular diastolic dysfunction and left atrial enlargement. Although measurable changes in the structure and function of the right ventricle have been reported in association with OSA, the clinical significance of these changes is uncertain. Right ventricular failure in OSA appears to be uncommon and is more likely if there is coexisting left-sided heart disease or chronic hypoxic respiratory disease.
Publisher: European Respiratory Society (ERS)
Date: 02-1995
DOI: 10.1183/09031936.95.08020230
Abstract: The gamma aminobutyric acid (GABA)-B agonist, baclofen, is a centrally-acting, anti-spasmodic agent and muscle relaxant used in spinal cord lesions, multiple sclerosis and other neurological disorders. In a previous pilot study of quadriplegic patients, 75% of whom were treated with baclofen, we found a high prevalence of sleep-disordered breathing. Because of the depressant effects of GABA on the central nervous system, we hypothesized that baclofen might aggravate sleep-disordered breathing in susceptible in iduals by depressing central ventilatory drive, increasing upper airway obstruction and/or increasing the arousal threshold to apnoea. We therefore conducted a double-blind, placebo-controlled, cross-over study of baclofen 25 mg, administered before sleep in 10 snorers with mild sleep-disordered breathing (respiratory disturbance index 30 events per sleep hour). Each subject underwent two standard polysomnographic assessments, one week apart. Total sleep time was significantly prolonged by baclofen (placebo 356 +/- 9.9 SEM min baclofen 386 +/- 9.9 min). Both nonrapid eye movement(REM) and REM sleep duration were increased (nonREM: placebo 295 +/- 6.8 min baclofen 311 +/- 8.9 min REM: placebo 61 +/- 7.5 min baclofen 76 +/- 9.0 min). Time spent awake after sleep onset was reduced after baclofen (placebo 71 +/- 10.3 min baclofen 51 +/- 9.7 min). There was a slight reduction in mean overnight oxygen saturation (placebo 95.2 +/- 0.5% baclofen 94.4 +/- 0.7%). The frequency of apnoeas plus hypopnoeas (respiratory disturbance index (RDI)) did not change significantly (placebo 9 +/- 1.8 events.h-1 baclofen 13 +/- 3.4 events.h-1).(ABSTRACT TRUNCATED AT 250 WORDS)
Publisher: American Thoracic Society
Date: 1997
DOI: 10.1164/AJRCCM.155.1.9001312
Abstract: Changes in sleep posture have been shown to improve obstructive sleep apnea (OSA). To investigate the mechanisms by which this occurs we assessed upper airway stability in eight patients with severe OSA in three postures (supine, elevated to 30 degrees, and lateral). We used a specially adapted nasal continuous positive airway pressure (nCPAP) mask to measure upper airway closing pressure (UACP) and upper airway opening pressure (UAOP) during non-REM sleep. Statistical comparisons were made between postures using ANOVA for repeated measures. Elevation resulted in a less collapsible airway compared with both the supine and lateral positions (mean UACP: 30 degrees elevation -4.0 +/- 3.2 compared with supine 0.3 +/- 2.4 cm H2O, p < 0.05 and lateral -1.1 +/- 2.2 cm H2O, p < 0.05). Supine UACP and lateral UACP were not significantly different. Elevation or lateral positioning produced a 50% reduction in mean UAOP (supine 10.4 +/- 3.5 cm H2O compared with 30 degrees elevation 5.3 +/- 2.1, p < 0.05 and lateral 5.5 +/- 2.1 cm H2O, p < 0.05). We conclude that in severely affected OSA patients upper body elevation, and to a lesser extent lateral positioning, significantly improve upper airway stability during sleep, and may allow therapeutic levels of nCPAP to be substantially reduced.
Publisher: Elsevier BV
Date: 12-2007
Publisher: European Respiratory Society (ERS)
Date: 25-10-2019
DOI: 10.1183/13993003.01270-2018
Abstract: Does sertraline provide symptomatic relief for chronic breathlessness in people with advanced disease whose underlying cause(s) are optimally treated? 223 participants with chronic breathlessness (modified Medical Research Council breathlessness scale ≥2) who had optimal treatment of underlying cause(s) were randomised 1:1 to sertraline 25–100 mg (titrated upwards over 9 days) or placebo for 4 weeks. The primary outcome was the proportion who had an improvement in intensity of current breathlessness % from baseline on a 100-mm visual analogue scale. The proportion of people responding to sertraline was similar to placebo for current breathlessness on days 26–28 (OR 1.00, 95% CI 0.71–1.40) and for other measures of breathlessness. Quality of life in the sertraline arm had a higher likelihood of improving than in the placebo arm over the 4 weeks (OR 0.21, 95% CI 0.01–0.41 p=0.044). No differences in performance status, anxiety and depression, or survival were observed. Adverse event rates were similar between arms. Sertraline does not appear to provide any benefit over placebo in the symptomatic relief of chronic breathlessness in this patient population.
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.JAMDA.2017.09.003
Abstract: Patients with chronic obstructive pulmonary disease (COPD) can be classified into groups A/C or B/D based on symptom intensity. Different threshold values for symptom questionnaires can result in misclassification and, in turn, different treatment recommendations. The primary aim was to find the best fitting cut-points for Global initiative for chronic Obstructive Lung Disease (GOLD) symptom measures, with an modified Medical Research Council dyspnea grade of 2 or higher as point of reference. After a computerized search, data from 41 cohorts and whose authors agreed to provide data were pooled. COPD studies were eligible for analyses if they included, at least age, sex, postbronchodilator spirometry, modified Medical Research Council, and COPD Assessment Test (CAT) total scores. Receiver operating characteristic curves and the Youden index were used to determine the best calibration threshold for CAT, COPD Clinical Questionnaire, and St. Georges Respiratory Questionnaire total scores. Following, GOLD A/B/C/D frequencies were calculated based on current cut-points and the newly derived cut-points. A total of 18,577 patients with COPD [72.0% male mean age: 66.3 years (standard deviation 9.6)] were analyzed. Most patients had a moderate or severe degree of airflow limitation (GOLD spirometric grade 1, 10.9% grade 2, 46.6% grade 3, 32.4% and grade 4, 10.3%). The best calibration threshold for CAT total score was 18 points, for COPD Clinical Questionnaire total score 1.9 points, and for St. Georges Respiratory Questionnaire total score 46.0 points. The application of these new cut-points would reclassify about one-third of the patients with COPD and, thus, would impact on in idual disease management. Further validation in prospective studies of these new values are needed.
Publisher: American Thoracic Society
Date: 05-1999
DOI: 10.1164/AJRCCM.159.5.9805086
Abstract: It is controversial whether obstructive sleep apnea (OSA) causes pulmonary hypertension (PH) in the absence of hypoxemic lung disease. To investigate this further we measured awake pulmonary hemodynamics, pulmonary gas exchange, and small airways function in 32 patients with OSA (apnea- hypopnea index, mean +/- SE, 46.2 +/- 3. 9/h) who had normal screening lung function. Pulmonary artery pressure (Ppa) and cardiac output were measured by Doppler echocardiography at three levels of inspired oxygen (FIO2 0.50, 0.21, and 0.11) and during incremental increases in pulmonary blood flow (10, 20, and 30 microgram/kg/min dobutamine infusions) while breathing 50% oxygen. Eleven patients had PH (mean Ppa >/= 20 mm Hg, Group I). They did not differ from patients without PH (Group II) in lung function, severity of sleep-disordered breathing, age, or body mass. Compared with Group II, Group I patients had increased small airways closure during tidal breathing (FRC-closing capacity: Group I, -0.16 +/- 0.11 Group II, 0.27 +/- 0.09 L p < 0.05), more ventilation-perfusion inequality (AaPO2: 23.8 +/- 2.8 19.8 +/- 1.4 mm Hg p = 0.08), a greater pulmonary artery pressor response to hypoxia (DeltaPpa FIO2, 0.50 to 0.11: 16.4 +/- 1.93 6.4 +/- 0.77 mm Hg p < 0.05) and a marked rise in Ppa during increased pulmonary blood flow. We conclude that PH may develop in some patients with OSA without lung disease and that it is associated with small airways closure during tidal breathing and heightened pulmonary pressor responses to hypoxia and during increased pulmonary blood flow. Such changes are consistent with remodeling of the pulmonary vascular bed in affected patients with OSA, seemingly unrelated to severity of sleep-disordered breathing.
Publisher: Oxford University Press (OUP)
Date: 16-04-2019
DOI: 10.1136/POSTGRADMEDJ-2018-136380
Abstract: Pleural diseases are common in clinical practice. Doctors in training often encounter these patients and are expected to perform diagnostic and therapeutic pleural procedures with confidence and safely. However, pleural procedures can be associated with significant complications, especially when performed by less experienced. Structured training such as use of training manikin and procedural skills workshop may help trainee doctors to achieve competence. However, high costs involved in acquiring simulation technology or attending a workshop may be a hurdle. We hereby describe a training model using a simple manikin developed in our institution and provide an effective way to document skill acquisition and assessment among trainee medical officers. This was a prospective observational study. The need for training, competence and confidence of trainees in performing pleural procedures was assessed through an online survey. Trainees underwent structured simulation training through a simple manikin developed at our institute. Follow-up survey after the training was then performed to access confidence and competence in performing pleural procedures. Forty-seven trainees responded to an online survey and 91% of those expressed that they would like further training in pleural procedure skills. 81% and 85% of responders, respectively, indicated preferred method of training is either practising on manikin or performing the procedure under supervision. Follow-up survey showed improvement in the confidence and competence. Our pleural procedure training manikin model is a reliable, novel and cost-effective method for acquiring competences in pleural procedures.
Publisher: Elsevier BV
Date: 05-1993
Abstract: In preparation for a vasodilator study on chronic obstructive pulmonary disease (COPD), we investigated the reliability of recently described pulsed Doppler techniques for estimating pulmonary artery pressure (PAP) and cardiac output (CO). Our aims were to determine the following: (1) the imaging success rate for pulsed Doppler measurements (2) the repeatability of the measurements, and interobserver and intraobserver variability and (3) the accuracy of Doppler compared with catheter measurements. Doppler studies were attempted in 81 patients (cardiac disease [23], COPD [22], sleep apnea [32], and normal subjects [4]). Suitable images were obtained in 68 subjects (84 percent) and in 76 subjects (94 percent) for PAP and CO estimations, respectively. The lowest imaging success rates were in COPD patients (68 percent for PAP and 86 percent for CO estimation). Repeatability of the techniques was assessed in four cardiac patients and three healthy volunteers by performing four replicate studies in each subject over 1 h. Intrasubject coefficient of variation was < 10 percent for PAP and < 5 percent for CO. The intraobserver variability for Doppler estimation of systolic and mean PAP was 5.5 percent and 5.8 percent, respectively. The corresponding values for interobserver variability were 6.7 percent and 6.2 percent. Intraobserver and interobserver variability for "nongeometric" method of estimating CO was 5.1 percent and 5.9 percent, respectively. Agreement was good between catheter-measured and Doppler-estimated PAP in the 27 patients tested (cardiac [19] and COPD [8]) for both mean and systolic pressures (r = 0.96 and r = 0.97, respectively). The correlations between thermodilution and Doppler estimations of CO in eight COPD patients were 0.77 ("geometric" technique) and 0.97 ("nongeometric" technique). We conclude that pulsed Doppler techniques can be used to obtain accurate and reproducible quantitative information on pulmonary hemodynamics in a wide range of patients. Suitable Doppler images can be obtained in more than two thirds of COPD patients.
Publisher: Informa UK Limited
Date: 05-2011
DOI: 10.1586/ERV.11.53
Publisher: Elsevier BV
Date: 05-1993
Abstract: Pulmonary hypertension in chronic obstructive pulmonary disease (COPD) is associated with a poor prognosis. Reduction of pulmonary artery pressure in COPD by prolonged oxygen treatment has been shown to be associated with increased survival. In an attempt to find a suitable pharmacologic method of reducing pulmonary artery pressure and pulmonary vascular resistance in COPD, we enrolled 13 stable pulmonary-hypertensive, hypoxemic COPD patients in a study to test the effects of felodipine, a relatively new, vascular-selective calcium antagonist. Doppler echocardiography was used to estimate pulmonary artery pressure and cardiac output before treatment, 2, 7, and 12 weeks during felodipine treatment (10 to 20 mg/d), and after a 1-week placebo washout period. Measurements of lung function, arterial blood gases, and exercise capacity during an incremental bicycle ergometer test were also performed at intervals during the study period. Three patients withdrew from the study and of the remaining 10, 8 had some side effects of medication (peripheral edema or headache) that improved either spontaneously or following a reduction in drug dose. In the 10 patients who completed the study (8 male mean age, 67 years), felodipine resulted in significant reductions in mean pulmonary artery pressure (22 percent) and total pulmonary (vascular) resistance (30 percent) and increases in cardiac output (15 percent) and stroke volume (13 percent) compared with baseline measurements and those taken after placebo washout. These effects were sustained over the 12 weeks of felodipine treatment. There was no adverse effect of felodipine treatment on pulmonary gas exchange at rest or during exercise and no change in lung function or exercise capacity. We conclude that in pulmonary hypertensive, hypoxemic COPD patients, felodipine substantially improves pulmonary hemodynamics.
Publisher: MDPI AG
Date: 08-08-2022
DOI: 10.3390/DIABETOLOGY3030033
Abstract: Obstructive sleep apnoea (OSA) and type 2 DM mellitus (T2DM) share obesity as a major risk factor. Furthermore, these conditions share overlapping mechanisms including inflammation, activation of the autonomic nervous system, and hypoxia-linked endocrinopathy. Hence, the pathogenesis of the two conditions may be more closely related than previously recognised. This raises the question of whether treatment of OSA might assist resolution of obesity and/or T2DM. Here, we present a narrative review of the literature to identify clinical and scientific data on the relationship between obstructive sleep apnoea and T2DM control. We found there is a paucity of adequately powered well-controlled clinical trials to directly test for a causal association. While routine screening of all T2DM patients with polysomnography cannot currently be justified, given the high prevalence of sleep disordered breathing in the overweight/obese population, all T2DM patients should at a minimum have a clinical assessment of potential obstructive sleep apnoea risk as part of their routine clinical care. In particular, screening questionnaires can be used to identify T2DM subjects at higher risk of OSA for consideration of formal polysomnography studies. Due to morbid obesity being a common feature in both T2DM and OSA, polysomnography should be considered as a screening tool in such high-risk in iduals.
Publisher: Massachusetts Medical Society
Date: 03-01-2019
Publisher: Wiley
Date: 09-2009
Publisher: Informa UK Limited
Date: 16-03-2017
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.JPAINSYMMAN.2018.07.010
Abstract: Pulmonary arterial hypertension (PAH) affects people of all ages and is associated with poor prognosis. Chronic breathlessness affects almost all people with PAH. This randomized, placebo-controlled, double-blind, crossover study aimed to evaluate the effects of regular, low-dose, extended-release (ER) morphine for PAH-associated chronic breathlessness. Participants with PAH-associated chronic breathlessness were randomized to 1) seven days of ER morphine 20 mg, 2) seven-day washout, and 3) seven days of identically looking placebo, or vice versa. Primary end points were breathlessness "right now"-morning and evening-measured with a Visual Analogue Scale. Secondary end points included additional breathlessness measures, quality of life, function, harms, and blinded treatment preference (ACTRN12609000209291). Within a period of seven years, 50 patients were assessed in detail and 23 (46%) were randomized (despite broad eligibility criteria). Four participants withdrew while taking morphine. Nineteen participants completed the study. Breathlessness "right now" was higher on morphine compared with placebo both for morning [mean (M) ± SD 31.7 ± 25 mm vs. 26.9 ± 22 mm effect size (80% CI) = -0.22 (-0.6 to 0.2)] and evening [(M ± SD 33.5 ± 28 mm vs. 25.6 ± 21 mm effect size (80% CI) = -0.33 (-0.8 to 0.1)]. All secondary measures of breathlessness were higher with morphine as were nausea and constipation. This study does not support a Phase III study of ER morphine for people with PAH-associated chronic breathlessness. Recruiting to the target s le size was difficult, the direction of effect in every measure of breathlessness favored placebo and morphine generated more harms.
Location: North Macedonia
No related grants have been discovered for Dimitar Sajkov.