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Biomedical subjects

R S Goldstein

Publications and source records attributed to R S Goldstein.

At least 55 records · Page 3Linked to original sources
PubMed1997

Economic analysis of respiratory rehabilitation.

STUDY OBJECTIVE: We report on the incremental costs associated with improvements in health-related quality of life (HRQL) following 6 months of respiratory rehabilitation compared with conventional community care. DESIGN: Prospective randomized controlled trial of rehabilitation. SETTING: A respiratory rehabilitation unit. PARTICIPANTS: Eighty-four subjects who completed the rehabilitation trial. INTERVENTION: Two months of inpatient rehabilitation followed by 4 months of outpatient supervision. MEASUREMENTS AND RESULTS: All costs (hospitalization, medical care, medications, home care, assistive devices, transportation) were included. Simultaneous allocation was used to determine capital and direct and indirect hospitalization costs. The incremental cost of achieving improvements beyond the minimal clinically important difference in dyspnea, emotional function, and mastery was $11,597 (Canadian). More than 90% of this cost was attributable to the inpatient phase of the program. Of the nonphysician health-care professionals, nursing was identified as the largest cost center, followed by physical therapy and occupational therapy. The number of subjects needed to be treated (NNT) to improve one subject was 4.1 for dyspnea, 4.4 for fatigue, 3.3 for emotion, and 2.5 for mastery. CONCLUSION: Cost estimates of various approaches to rehabilitation should be combined with valid, reliable, and responsive measures of outcome to enable cost-effectiveness measures to be reported. Comparison studies with the same method are necessary to determine whether the improvements in HRQL that follow inpatient rehabilitation are cheap or expensive. Such information will be important in identifying the extent to which alternative approaches to rehabilitation can influence resource allocation. A consideration of cost-effectiveness from the perspective of NNT may be useful in the evaluation of health-care programs.

Aged↗
PubMed1996

Meta-analysis of respiratory rehabilitation in chronic obstructive pulmonary disease.

BACKGROUND: Respiratory rehabilitation is increasingly recognised as an important part of the management of patients with chronic obstructive pulmonary disease (COPD). The widespread application of such programmes should be preceded by evidence of directly attributable improvements in function. We assessed the effect of respiratory rehabilitation on exercise capacity and health-related quality of life (HRQL) in patients with COPD. METHODS: We carried out a meta-analysis of randomised controlled trials of respiratory rehabilitation in patients with COPD that assessed functional or maximal exercise capacity, HRQL, or both. Respiratory rehabilitation was defined as exercise training (for at least 4 weeks) with or without education, psychological support, or both. The most commonly used measure for HRQL was the chronic respiratory questionnaire, in which responses were presented on a 7-point scale. The control groups received no rehabilitation. Within each trial and for each outcome an effect size was calculated; the effect sizes were then pooled by a random-effects model. The overall effect of treatment was compared with its minimum clinically important difference (MCID)--defined as the smallest difference perceived as important by the average patient. FINDINGS: We included 14 trials. Significant improvements were found for all the outcomes. For two important features of HRQL, dyspnoea and mastery, the overall treatment effect was larger than the MCID: 1.0 (95% CI 0.6-1.5) and 0.8 (0.5-1.2), respectively, compared with an MCID of 0.5. For functional exercise capacity (6-min walk test), the overall effect was 55.7 m (27.8-92.8), and for maximum exercise capacity (incremental cycle ergometer test), 8.3 W (2.8-16.5). Functional exercise capacity showed heterogeneity that could not be explained by the sensitivity analyses. INTERPRETATION: Respiratory rehabilitation relieves dyspnoea and improves the control over COPD. These improvements are clinically important. The value of the improvement in exercise capacity is not clear. Respiratory rehabilitation is an effective part of care in patients with COPD.

Exercise Therapy↗
PubMed1996

Rescue of sensory ganglia that are programmed to degenerate in normal development: evidence that NGF modulates proliferation of DRG cells in vivo.

The dorsal root ganglia (DRG, spinal ganglia) are a metameric series of structures that develop from neural crest cells within the dorsal somitic mesoderm. A striking element of patterning within this meristic series is the disappearance of the five or six most rostral DRG early in the embryonic development of birds and mammals. The transient DRG have been named "Froriep's ganglia" after their 19th century discoverer (reviewed in Lim et al., 1987). The ontogeny of the longest surviving Froriep's ganglion of the chick embryo, DRG C2, has recently been examined in detail (Rosen et al., 1996). At St. 18 (Embryonic Day (E)2.5+), the C2 DRG had the same shape and volume as permanent ganglia C5 and C6. C2's development first diverged from that of normal DRG at St. 19 (E3-), when C2 was observed to be half the size and shaped differently from its neighbors, and its peripheral nerve root began to degenerate. Both lower proliferation and higher apoptosis rates contribute to the reduced size of C2 compared to normal DRG at St. 19-20. One-third fewer C2 cells were found to be in S-phase when compared to neighboring ganglia, and apoptotic cells were more than three times more abundant in C2 than in conventional DRG at this stage. Since growth factors modulate both proliferation and apoptosis, we postulated that these molecules and/or their receptors might be responsible for the difference in fate between C2 and C5. In order to begin to evaluate this hypothesis, we have now treated embryos with nerve growth factor (NGF) in ovo. NGF treatments partially rescued C2, producing a 50% reduction in the normal difference in size between C2 and C5 at St. 23. At least part of this rescue could be accounted for by increased levels of proliferation in the NGF-treated C2 compared to those in control embryos. Proliferation in normal DRG C5 was unaffected by NGF application. NGF treatment rescued DRG cells in both C2 and C5 from cell death. Staining of pycnotic nuclei revealed that NGF dramatically reduced the death in the C2 ganglia. In addition to providing insight into the early patterning of the DRG, our results shed new light on the best-studied neurotrophic factor, NGF. Our finding is the first direct evidence for a role for NGF in control of DRG cell proliferation in vivo.

Animals↗
PubMed1996

Interest among gay/bisexual men in greater Boston in participating in clinical trials of preventive HIV vaccines.

To estimate interest in HIV preventive vaccine trials, we administered questionnaires to two otherwise demographically similar cohorts of older (mean 40 years) and younger (mean 23 years) gay men in Boston. Questionnaire responses were linked to concurrent behavioral and demographic data. Univariate analyses, performed separately for older and younger cohorts, identified factors that distinguished participants who were "very interested" from those who were "not at all interested". Multivariate logistic regression analyses were used to adjust for confounding. Among all 630 participants, 215 (34%) were "not at all" interested in participating, 306 (49%) were "somewhat" interested, and 102 (16%) were "very" interested. Older men were significantly more likely than younger men to be "very" interested and less likely to be "not at all interested." Among both older and younger men, perceived peer willingness to enroll in vaccine trials predicted interest after adjusting for confounding. Among older men, optimism about success in vaccine development also predicted interest. In the younger cohort, men recruited in community settings (e.g., bars, nightclubs) were more interested in vaccine trial participation than were those recruited by outreach workers and word of mouth on college campuses. Vaccine-induced seroconversion evoked significant concern.

AIDS Vaccines↗
PubMed1996

Growth, proliferation, and cell death in the ontogeny of transient DRG (Froriep's ganglia) of chick embryos.

A striking example of axial patterning in nervous system development is the unusual fate of dorsal root ganglia (DRG) that develop in the most rostral somites, the Froriep's ganglia. In amniotes, the DRG that develop adjacent to the occipital (cranial) and the first cervical segments of the CNS "disappear" early in embryonic development. In contrast, all other DRG are present throughout the animal's life. We here reexamine in greater detail the ontogeny of the longest surviving Froriep's ganglion of the chick embryo, DRG C-2. By 50 h of development (stage, st. 15), an anlagen of a DRG had formed in C-2 that was indistinguishable from those of adjacent "permanent" ganglia. At st. 18 [embryonic day (E) 2.5+], the C-2 DRG had the same shape and volume as permanent ganglia C-5 and C-6. C-2's development first diverged from that of normal DRG at st. 19 (E3-), when C-2 was observed to be half the size and shaped differently from its neighbors, and its peripheral nerve root began to degenerate. Two cellular mechanisms appear to contribute to the reduced size of C-2 compared to normal DRG at st. 20 at this early stage: lower proliferation and higher apoptosis rates. One-third fewer C-2 cells were found to be in the S phase when compared to neighboring ganglia, and apoptotic cells were more than three times more abundant in C-2 than in conventional DRG at this stage. The C-2 DRG continued to grow, but at a slower pace than neighboring ganglia through st. 32 (E7). At the height of the normal programmed DRG cell death in normal cervical DRG at st. 28 (E6), even more massive apoptosis occurred in C-2, which resulted in the absence of this ganglion in 80% of st. 36 (E10) embryos. A recent study demonstrated that the overexpression of a single Hox gene can "rescue" the C-2 DRG in transgenic mice. We speculate that Hox genes may produce the difference in fate between C-2 and normal DRG by modulating proliferation and apoptosis via modified neurotrophic factor and/or receptor expression.

Animals↗
PubMed1996

Sex- and age-dependent acetaminophen hepato- and nephrotoxicity in Sprague-Dawley rats: role of tissue accumulation, nonprotein sulfhydryl depletion, and covalent binding.

Acetaminophen (APAP) produces sex-dependent nephrotoxicity and hepatotoxicity in young adult Sprague-Dawley (SD) rats and age-dependent toxicity in male rats. There is no information regarding the susceptibility of aging female SD rats to APAP toxicity. Therefore, the present studies were designed to determine if sex-dependent differences in APAP toxicity persist in aging rats and to elucidate factors contributing to sex- and age-dependent APAP hepatotoxicity and nephrotoxicity. Young adult (3 months old) and aging (18 months old) male and female rats were killed from 2 through 24 hr after receiving APAP (0-1250 mg/kg, ip) containing [ring-14C]APAP. Trunk blood was collected for determination of blood urea nitrogen (BUN) concentration, serum alanine aminotransferase (ALT) activity, and plasma APAP concentration; urine was collected for determination of glucose and protein excretion; and liver and kidneys were removed for determination of tissue glutathione (GSH) concentration, APAP concentration, and covalent binding. APAP at 1250 mg/kg induced nephrotoxicity (as indicated by elevations in BUN concentration) in 3-month-old females but not males, whereas APAP induced hepatotoxicity (as indicated by elevations in serum ALT activity) in 3-month-old males but not females. Sex differences in APAP toxicity were no longer apparent in 18-month-old rats. APAP at 750 mg/kg ip produced liver and kidney damage in 18-month-old but not 3-month-old male and female rats. No consistent sex- or age-dependent differences in serum, hepatic, and renal APAP concentrations were observed that would account for differences in APAP toxicity. No sex- or age-dependent differences in tissue GSH depletion or covalent binding of radiolabel from APAP in livers or kidneys were observed following APAP administration. Utilizing an affinity-purified polyclonal antibody raised against APAP, arylated proteins with electrophoretic mobility similar to those observed in mice were prominent in rat livers following APAP administration to 3- and 18-month-old rats of both sexes. In contrast, no arylated proteins were detected in any rat kidneys following APAP administration. Absence of immunochemically detectable proteins in rat kidney following APAP administration is in direct contrast to observations in mice and supports the hypothesis that mechanisms of APAP hepatotoxicity and nephrotoxicity in rats and mice are distinctly different. In conclusion, sex differences in APAP toxicity are observed only in young adult (3-month-old) rats and sex differences are organ-specific with males more susceptible to hepatotoxicity and females more susceptible to nephrotoxicity. Aging rats are more susceptible to APAP-induced damage to both the liver and the kidney than are 3-month-old rats but sex differences are no longer apparent in 18-month-old rats. The mechanisms contributing to sex- and age-dependent differences in APAP toxicity cannot be attributed to differences in tissue APAP concentrations, GSH depletion, or covalent binding.

Acetaminophen↗
PubMed1996

Assessing the minimal important difference in symptoms: a comparison of two techniques.

We have developed a method for estimating the minimally important difference (MID) for health status measures. Whereas the conventional approach requires patients to judge themselves relative to their memories, our method requires patients to judge themselves relative to others with the same condition. In this study we examined whether our method (based on between-patient differences) and the conventional method (based on within-patient changes) provides comparable estimates of the MID for one health status measure: the Chronic Respiratory Questionnaire. Patients with chronic obstructive pulmonary disease who were participating in a supervised respiratory rehabilitation program were included if they were in stable health (n = 112). Their mean score per question in the Chronic Respiratory Questionnaire was 4.5 (range, 1 to 7; where bigger values indicate better health). Our method estimated that the MID was 0.5 (95% confidence interval 0.4 to 0.7). This estimate was similar to the MID previously found using the conventional method. These observations support the role of the Chronic Respiratory Questionnaire for measuring patient's symptoms, the validity of our approach for assessing the MID, and an estimate on the order of 0.5 as the threshold for this particular health status measure.

Adaptation, Psychological↗
PubMed1996

CPAP improves inspiratory muscle strength in patients with heart failure and central sleep apnea.

Patients with congestive heart failure (CHF) suffer from respiratory muscle weakness which may contribute to dyspnea. Nasal continuous positive airway pressure (NCPAP) can improve left ventricular ejection fraction (LVEF) and reduce dyspnea in patients with CHF and Cheyne-Stokes respiration with central sleep apnea (CSR-CSA) but its effects on respiratory muscle strength are not known. We therefore studied the effects of NCPAP on maximal inspiratory and expiratory pressures (MIP and MEP, respectively), LVEF, dyspnea, and fatigue in patients with chronic CHF and CSR-CSA over 3 mo. Eight patients were randomized to control and nine to nightly NCPAP. There were no significant changes in any of these factors in the control group during the study. In contrast, among the NCPAP group, MIP increased from 79.3 +/- 8.1 to 90.7 +/- 10.4 cm H2O (mean +/- SEM; p < 0.02), LVEF increased from 24.0 +/- 4.0 to 32.6 +/- 6.6% (p < 0.02) and symptoms of dyspnea and fatigue were alleviated. However, MEP did not change. In addition, the number of apneas and hypopneas decreased from 49 +/- 11 to 17 +/- 7 per hour of sleep (p < 0.001) and mean low Sao2 during sleep increased from 87.9 +/- 1.0 to 93.0 +/- 1.0% (p < 0.01). Our data indicate that nightly application of NCPAP in patients with CHF and CSR-CSA improves inspiratory muscle strength and LVEF, and relieves dyspnea and fatigue.

Aged↗
PubMed1996

Spirometry and dyspnea in patients with COPD. When small differences mean little.

OBJECTIVE: To determine when a difference in FEV1 is sufficiently large to be associated with a noticeable difference in dyspnea symptoms for patients with chronic lung disease. DESIGN: Cross-sectional analysis of 15 groups (n = 112 patients, 832 contrasts). SETTING: Respiratory rehabilitation program. PATIENTS: Patients with COPD (mean FEV1 = 35% predicted). MEASURES: Patients' perspectives assessed through subjective comparison ratings of dyspnea and of overall health. Relation between the FEV1 and patients' perspectives determined the smallest difference in spirometry that was associated with a noticeable difference in patients' symptoms. RESULTS: The FEV1 was moderately correlated with patients' ratings of dyspnea (r = 0.29; 95% confidence interval (CI), 0.22 to 0.35). In contrast, the FEV1 was minimally correlated with patients' ratings of overall health (r = 0.10; 95% CI, 0.03 to 0.17). The FEV1 needed to differ by 4% predicted for the average patient to stop rating his or her dyspnea as "about the same" and start rating his or her dyspnea as either "a little bit better" or "a little bit worse" relative to other patients (95% CI, 1.5 to 6.5). This was equivalent to the average patient's FEV1 increasing by 112 mL (starting from 975 mL and ending at 1,087 mL). CONCLUSIONS: Some statistically significant differences in the FEV1 are so small that they may not represent important differences in symptoms for the average patient with severe COPD; an awareness of the smallest difference in FEV1 that is noticeable to patients can help clinicians interpret the effectiveness of symptomatic treatments.

Aged↗
PubMed1996

Chest wall oscillation at 1 Hz reduces spontaneous ventilation in healthy subjects during sleep.

STUDY OBJECTIVE: The objective was to determine whether external chest wall oscillation (ECWO) during sleep (1) reduced spontaneous ventilation while maintaining adequate gas exchange over several hours, (2) influenced the quality and distribution of sleep, and (3) increased the number of respiratory events. DESIGN: Prospective controlled study with counterbalanced order of intervention. SETTING: Pulmonary function sleep laboratory. PARTICIPANTS: Seven healthy volunteers. INTERVENTION: One night of ECWO at 1 Hz (I:E = I:I; oscillation mean [SEM] from - 11.1 [0.7] to 6.0 [0.7] cm H2O) and a night during which the cuirass was applied without ECWO. MEASUREMENTS AND RESULTS: ECWO resulted in a significant decrease in spontaneous minute ventilation (VE) in all stages of sleep. ECWO was associated with a reduction in the total sleep time and a reduction in rapid eye movement (REM) sleep. The number of stage changes and the sleep efficiency did not change significantly. The mean PCO2 was similar between the control and cuirass nights (44 to 46 mm Hg). There was a significant decrease in the mean PCO2 during stage 1 (41 [2] mm Hg) and stage 2 (42 [2] mm Hg) sleep during the ECWO night. The mean arterial oxygen saturation (SaO2) was maintained at 96 to 97% throughout sleep during the control, cuirass, and ECWO nights. The apnea + hypopnea index increased (p < 0.05) during ECWO mostly due to an increase in the number of hypopneas in stage 2 sleep. During ECWO, 18 of 30 respiratory events were associated with an arousal, whereas only 2 events were associated with an arousal during the control night. CONCLUSIONS: ECWO can be tolerated for several hours and will assist ventilation while maintaining normal mean PCO2 and mean SaO2 during sleep. Monitoring of the apnea + hypopnea index and the SaO2 is recommended at the time of application. Clinical trials to define the most appropriate indications for ECWO are now necessary.

Adult↗
PubMed1995

Initial axial level-dependent differences in size of avian dorsal root ganglia are imposed by the sclerotome.

We have recently shown that there is very early variation in dorsal root ganglia (DRG) size based on their axial position. From the time of their condensation at Stage (St.) 20 (Embryonic Day 3), before the onset of apoptosis, the ganglia in brachial segments 14 and 15 are more than 80% larger on the average than those in cervical 5 and 6. This difference in volume is due to increased numbers of cells in the brachial DRG. In addition, the rostrocaudal length was found to be significantly greater for brachial ganglia, and the greater length of the brachial ganglia was found to be correlated with a greater length of brachial than cervical sclerotomes. It was therefore proposed that the difference in DRG size at the time of gangliogenesis is likely to arise from colonization by a larger initial number of neural crest cells of the longer adjacent rostral sclerotomes in brachial somites. In the present work, we have performed two types of experiments to test this hypothesis. First, we have performed heterotopic grafts of segmental plate mesoderm from cervical to brachial levels and vice versa. In all of these grafts, the sclerotomes developed with a rostrocaudal extent (length) corresponding to their level of origin in the donor embryo. DRG that formed in the grafted mesoderm attained a length appropriate to that of ganglia developing in segments of the axial level of the donor mesoderm, not that of the host. Second, we have estimated proliferation of DRG cells at St. 20 using HNK-1/bromodeoxyuridine double-stain immunocytochemistry. The percentage of cells in S-phase at both brachial and cervical levels of the neuraxis in newly formed ganglia was observed to be the same. These two lines of evidence strongly argue that the initial difference in size between DRG at different axial levels is not intrinsic, but rather is imposed by the mesodermal microenvironment in which they develop, as is the case for DRG segmentation. This is in contrast to what may occur in the hindbrain, where determination of rhombomere identity and neural crest segmentation are thought to be intrisic to the nervous system.

Animals↗
PubMed1995

Biliary epithelial cell proliferation following alpha-naphthylisothiocyanate (ANIT) treatment: relationship to bile duct obstruction.

These studies were designed to evaluate the importance of bile duct obstruction in the pathogenesis of alpha-naphthylisothiocyanate (ANIT)-induced biliary epithelial cell (BEC) hyperplasia in rats. Hepatobiliary function and morphology were evaluated in adult male Sprague-Dawley rats 16, 24, 48, 72, 120, and 168 hr after a single oral dose of ANIT (0, 25, 75, or 150 mg/kg). After 75 or 150 mg/kg ANIT, multifocal bile duct obstruction was observed at 48 and 72 hr and preceded BEC hyperplasia which occurred at 120 and 168 hr. BEC proliferation, reflected by 5-bromo-2'-deoxyuridine (BrdU) incorporation, occurred at doses and at time points coinciding with BEC necrosis and/or bile duct obstruction. In contrast, 25 mg/kg ANIT produced minimal BEC damage and no evidence of bile duct obstruction or BEC hyperplasia. In a separate experiment, BEC proliferation was evaluated following bile duct ligation or ANIT treatment (150 mg/kg). The onset and peak of BEC proliferation occurred 24 and 48 hr, respectively, following bile duct obstruction resulting from either ligation or ANIT treatment. Furthermore, BEC proliferation occurred at all levels of the biliary tree in both bile duct-ligated and ANIT-treated rats. These data indicate that (a) dose-response curves for ANIT-induced bile duct obstruction and BEC hyperplasia are similar; (b) ANIT-induced BEC proliferation and bile duct obstruction precedes BEC hyperplasia; (c) BEC proliferation occurred at doses/timepoints associated with BEC damage and bile duct obstruction; and (d) once ANIT-induced bile duct obstruction occurs, the spatial and temporal aspects of BEC proliferation are comparable to those following biliary obstruction induced by bile duct ligation. Collectively, these data suggest that ANIT-induced BEC hyperplasia is secondary to intrahepatic bile duct obstruction.

1-Naphthylisothiocyanate↗
PubMed1995

Treatment of congestive heart failure and Cheyne-Stokes respiration during sleep by continuous positive airway pressure.

A previous uncontrolled study suggested that nasal continuous positive airway positive airway pressure (NCPAP) may improve left ventricular ejection fraction (LVEF) in patients with congestive heart failure (CHF) and Cheyne-Stokes respiration with central sleep apnea (CSR-CSA). In order to more critically evaluate the effects of NCPAP on cardiac function, we undertook a randomized, controlled trial of NCPAP in 29 patients with heart failure and CSR-CSA over a 3-mo period, with LVEF as the primary outcome measure. Patients with CHF and associated CSR-CSA who were receiving optimal medical therapy were randomly assigned to a control group (n = 15) or a group receiving nightly NCPAP (n = 14). Twelve patients in each group completed the study. There was a greater improvement of LVEF in the NCPAP group than in the control group during the study (mean +/- SEM = 7.7 +/- 2.5 versus - 0.5 +/- 1.5%, p = 0.019). In addition, there was a significantly greater reduction in the number of apneas and hypopneas (-28.5 +/- 3.9 versus -6.1 +/- 7.0 per hour of sleep, p = 0.012) in the NCPAP group than in the control group. Significantly greater improvements in symptoms of fatigue (5.6 +/- 1.2 versus 0.8 +/- 0.7, p = 0.005) and disease mastery (3.6 +/- 1.1 versus -0.7 +/- 0.7, p = 0.031) were also observed in the NCPAP group. We conclude that in patients with chronic heart failure and CSR-CSA, nightly administration of NCPAP can attenuate CSR-CSA, improve cardiac function, and alleviate symptoms of heart failure.

Analysis of Variance↗
PubMed1995

Effect of external chest wall oscillation on gas exchange in healthy subjects.

Effective gas exchange can be maintained in animals without the need for endotracheal intubation using external chest wall oscillation (ECWO). The clinical application of this technique has been limited by equipment which was either impractical or uncomfortable. We evaluated a prototype of a new oscillator in which an oscillatory profile of negative and positive pressure was imposed on a negative baseline pressure within a cuirass. In seven healthy subjects, we identified an oscillatory cuirass pressure that could effectively ventilate but would not result in severe hypocapnia over 5 min. We then measured the influence of changing the frequency of oscillation (fo) on PaCO2 and spontaneous ventilation. Lastly, we evaluated the capability of this prototype to achieve targeted changes in chamber pressure. Subjects were ventilated with an inspiratory chamber pressure of -20 +/- 4 cm H2O, an expiratory chamber pressure of 5 cm H2O and an inspiratory-expiratory ratio of 1:1 at 9 oscillatory frequencies (fo: 1 to 5 Hz at 0.5-Hz increments). Each subject was ventilated for 5 min with consecutive periods of ECWO being separated from each other by 10 min of unassisted breathing. Oscillatory tidal volume (Vo) was sampled and PaCO2 was determined from the expired carbon dioxide concentration (FECO2) measured at the mouth. The change in PaCO2 (delta PaCO2) was the difference in PaCO2 immediately before and after ECWO. We found that delta PaCO2 and Vo were inversely related to fo. At 1 Hz the delta PaCO2 was -13 +/- 1 mm Hg and Vo was 344 +/- 34 mL in the absence of spontaneous breathing (fb = 0). At 3 Hz and above, at the chamber pressures used, the delta PaCO2 was small (-1 to -2 mm Hg) and the Vo was less than the predicted dead space. Subjects breathed spontaneously but at a frequency below that of their resting fb. With this prototype, chamber pressure changes up to 30 cm H2O could be accurately achieved at 1, 2.5, and 4 Hz. In conclusion, ECWO can provide effective ventilation among healthy adults in the presence or absence of spontaneous breathing, and further studies are warranted to explore its effectiveness in a variety of clinical circumstances.

Adult↗
PubMed1995

Home mechanical ventilation. Demographics and user perspectives.

Although the number of users of home mechanical ventilation (HMV) is increasing, information regarding the users' perceptions of the impact of HMV on their lives is incomplete. We administered an open-ended questionnaire to 98 (48 male, 50 female) HMV users aged (mean +/- SD) 47.4 +/- 19.5 years with COPD (9%), thoracic restrictive disease (43%), and neuromuscular disease (48%). At the time of survey, subjects had received HMV for 59.5 +/- 58.3 months. Fifty-three percent were ventilated electively. Ventilator use was continuous (18%), at night only (37%), or at night with occasional daytime use (45%). Twenty-seven (28%) individuals identified themselves as being totally independent while 32 (33%) rated themselves as partially dependent on caregiver assistance for daily activities. Only 37 (38%) considered that they had made an informed choice when first starting HMV whereas 54 (55%) did not. The impact of using a mechanical ventilator was believed to be overwhelmingly positive (87%). Positive comments regarding the impact of the ventilator on lifestyle were grouped in the following categories: life sustaining, facilitating mobility, and improving physical symptoms. Negative comments were grouped in the following categories: limiting mobility, equipment issues, and social implications. HMV users with a tracheostomy volunteered significantly fewer positive statements than those ventilated noninvasively (p < 0.05). Whereas 52 (53%) of users indicated that they had experienced initial difficulties in coping with the ventilator, only 11 (11%) identified difficulties at the time of the survey.

Adolescent↗
PubMed1995

Rehabilitation in end-stage COPD.

Patients with chronic obstructive lung disease represent a major impact on the utilization of health care resources. The high prevalence of impairment, disability and handicap among this population has led to the development of programmes in respiratory rehabilitation that aim to increase exercise tolerance and quality of life. Programme requirements may be quite modest but candidate evaluation will as-sist in selecting those most likely to benefit. The programme content should include supervised exercise, education and patient support. It is essential to employ appropriate outcome measures to evaluate the effectiveness of respiratory rehabilitation.

Adult↗