PubMed Health⌕ Search

Biomedical subjects

Daniel O Rodenstein

Publications and source records attributed to Daniel O Rodenstein.

8 recordsLinked to original sources

Health care costs and the sleep apnea syndrome.

This paper reviews some concepts on health economics from the authors personal perspective. It then examines the few papers published on health economics analysis applied to the field of sleep apnea syndrome, as well as the literature on the indirect (cost) consequences of sleep apnea syndrome. It appears that undiagnosed sleep apnea leads to a roughly two-fold increase in medical expenses in the years preceding the diagnosis and that treating the disease (once it is diagnosed) results in a decrease in these excess costs. It seems clear that sleep apnea increases the actual number of road traffic accidents, which will carry a definite, but unmeasured up to now, economic cost consequence. From the health economic point of view, the best diagnostic strategy is the one with the greater utility (i.e. polysomnography), although it could appear at first sight to be the more expensive one. From the patient's perspective, sleep apnea results in a given decrease in the possibilities to enjoy life, and its treatment is worth considering, especially if one takes into account that the actual treatment costs are not great. The global image of the health costs related to sleep apnea is still blurred, and further work is required to get the complete and clear picture of the economic consequences of this disease and of its treatment.

Health Care Costs↗

Comparison of lung deposition in two types of nebulization: intrapulmonary percussive ventilation vs jet nebulization.

BACKGROUND: So-called intrapulmonary percussive ventilation (IPV), frequently coupled with a nebulizer, is increasingly used as a physiotherapy technique; however, its physiologic and clinical values have not been rigorously assessed. STUDY OBJECTIVE: To compare in vitro and in vivo characteristics of the nebulizer of the IPV device (Percussionaire; Percussionaire Corporation; Sandpoint, ID) with those of standard jet nebulization (SST) [SideStream; Medic-Aid; West Sussex, UK]. DESIGN: Aerodynamic particle size was studied by an cascade impactor. The deposition of (99m)Tc-diethylenetriaminepenta-acetic acid was measured in 10 healthy subjects by tomoscintigraphy during spontaneous breathing with both nebulizers. MEASUREMENTS AND RESULTS: The mass median aerodynamic diameter (0.2 micro m vs 1.89 micro m for IPV and SST, respectively) and the fine-particle fraction (16.2% vs 67.5%, respectively) were significantly smaller with IPV. In vivo, respiratory frequency (RF) was lower with the IPV device (10.1 +/- 3.4 breaths/min vs 14.6 +/- 3.4 breaths/min, p = 0.002). Whole-body deposition was significantly higher with IPV (15.63% vs 9.31%), but it was due to a higher extrapulmonary deposition. Although intrapulmonary deposition (IPD) was not different with both devices (4.20% for SST vs 2.49% for IPV), it was much more variable with IPV, compared to SST. The penetration index into the lung was higher with IPV than SST when normalized for RF (0.045 +/- 0.018 breaths/min vs 0.026 +/- 0.013 breaths/min, p = 0.007). CONCLUSION: The two techniques showed comparable lung deposition despite a large difference in particle size. However, IPV IPD was too variable and thus too unpredictable to recommend its use for drug delivery to the lung.

Administration, Inhalation↗

Non-invasive ventilation and sleep.

In this paper, we review the effects of nocturnal mechanical ventilation on sleep. Indeed, although non-invasive assisted ventilation during sleep has been applied extensively, the exact effects of this treatment on sleep quality have not been thoroughly studied. In patients with severe chronic obstructive pulmonary disease and severe restrictive ventilatory defects, the resulting respiratory failure is aggravated by the specific effects of sleep on respiration. Non-invasive mechanical ventilation can lead to improvements in both ventilation and sleep quality. However, this is not always the case. Moreover, sleep-related leaks may jeopardize the efficiency of the ventilatory assistance which in turn may result in a deterioration in sleep quality. Non-invasive mechanical ventilation, if applied during sleep, should require a monitoring procedure during sleep with the aim of obtaining the best possible effects both on ventilation and on sleep quality.

Equipment Failure↗

Should all sleep apnoea patients be treated?

Sleep apnoea is a condition in which people stop breathing during sleep. A number of studies in general and worker populations have shown that the prevalence of an apnoea-hypopnoea index (AHI) >10 is in the range of 20%. Subjects with an AHI >10 that complain of excessive daytime somnolence, tiredness, asphyxic episodes during the night or non-refreshing sleep, among other symptoms, suffer from the sleep apnoea hypopnoea syndrome (SAHS). The prevalence of SAHS is around 4%. Owing to its high prevalence, clinical symptoms, probable secondary cardiovascular consequences and associated social problems, SAHS has a considerable impact on health, management of which is worth considering. Despite the fact that SAHS treatment has been challenged recent studies conclude that nasal continuous positive airway pressure (nCPAP) is undoubtedly effective in clearly symptomatic patients. Its use in clinical practice is adequately supported in the treatment of moderate to severe SAHS. Further studies are needed in order to define the lower range of symptoms to be treated. One of the most important problems encountered in this area results from the combination of two situations. On the one hand, different epidemiological studies have demonstrated that an AHI >10 without symptoms is present in around 15% of the general population. On the other hand, several studies suggest that having a high AHI, even without secondary symptoms, gives rise to some undesirable effects such as traffic accidents and cardiovascular consequences. In this context, comprehensive epidemiological studies are therefore warranted to define the role of nCPAP treatment especially in those subjects with a high AHI but with few or no symptoms.

Accidents, Traffic↗

Effects of hypocapnic hyperventilation on the response to hypoxia in normal subjects receiving intermittent positive-pressure ventilation.

OBJECTIVE: To confirm the hypothesis that the ventilatory response to hypoxia (VRH) may be abolished by hypocapnia. METHODS: We studied four healthy subjects during intermittent positive-pressure ventilation delivered through a nasal mask (nIPPV). Delivered minute ventilation (Ed) was progressively increased to lower end-tidal carbon dioxide pressure (PETCO(2)) below the apneic threshold. Then, at different hypocapnic levels, nitrogen was added to induce falls in oxygen saturation, a hypoxic run (N(2) run). For each N(2) run, the reappearance of a diaphragmatic muscle activity and/or an increase in effective minute ventilation (E) and/or deformations in mask-pressure tracings were considered as a VRH, whereas unchanged tracings signified absence of a VRH. For the N(2) runs eliciting a VRH, the threshold response to hypoxia (TRh) was defined as the transcutaneous oxygen saturation level that corresponds to the beginning of the ventilatory changes. RESULTS: Thirty-seven N(2) runs were performed (7 N(2) runs during wakefulness and 30 N(2) runs during sleep). For severe hypocapnia (PETCO(2) of 27.1 +/- 5.2 mm Hg), no VRH was noted, whereas a VRH was observed for N(2) runs performed at significantly higher PETCO(2) levels (PETCO(2) of 34.0 +/- 2.1 mm Hg, p < 0.001). Deep oxygen desaturation (up to 64%) never elicited a VRH when the PETCO(2) level was < 29.3 mm Hg, which was considered the carbon dioxide inhibition threshold. For the 16 N(2) runs inducing a VRH, no correlations were found between PETCO(2) and TRh and between TRh and both Ed and E. CONCLUSION: During nIPPV, VRH is highly dependent on the carbon dioxide level and can be definitely abolished for severe hypocapnia.

Adult↗

Effects of intermittent negative pressure ventilation on effective ventilation in normal awake subjects.

RATIONALE: Previous studies have shown that an increase in inspiratory pressure during nasal intermittent positive pressure ventilation (IPPV) does not result in increased effective minute ventilation (E) due to glottic interference. STUDY OBJECTIVES: To test the consequences of increases in negative pressure ventilation (NPV) on V(E). MATERIAL AND METHODS: Eight healthy awake subjects underwent NPV delivered by an iron lung. First, NPV was started at a respirator frequency (f) of 15 cycles per minute with an inspiratory negative pressure (INP) of - 15 cm H(2)O (F15-P15). Then, f was increased to 20 cycles per minute and INP was kept at - 15 cm H(2)O. Next, f was kept at 20 cycles per minute and INP was reduced to - 30 cm H(2)O (F20-P30). Finally, f was decreased to 15 cycles per minute and INP was kept at - 30 cm H(2)O. At each step and for each breath, effective tidal volume (VT), V(E), and end-tidal carbon dioxide pressure were measured. In three subjects, the glottis width was assessed using fiberoptic bronchoscopy. RESULTS: From spontaneous breathing to the first step of NPV (F15-P15), we observed an inhibition of the phasic inspiratory diaphragmatic electromyogram concomitant to a significant increase in V(E) (p < 0.0005). For the group as a whole, the increase in mechanical ventilation (from F15-P15 to F20-P30) resulted in significant increases in VT and V(E) leading to hypocapnia (p < 0.0005). Moreover, the glottis width did not decrease with the increase in mechanical ventilation. CONCLUSIONS: We conclude that in normal awake subjects, NPV allowed a significant increase in V(E). These results differ from those previously obtained with nasal IPPV in which the glottic width interferes with the delivered mechanical ventilation.

Adult↗