Archive for the ‘Duchenne Muscular Dystrophy’ Category

Ventilation and Breathing Pattern during Sleep in Duchenne Muscular Dystrophy: Conclusion

Ventilation and Breathing Pattern during Sleep in Duchenne Muscular Dystrophy: ConclusionSurface abdominal and rib cage motion reflect diaphragmatic and intercostal contributions to breathing, but the relationship of these indexes to diaphragm and intercostal function is more complex. In neuromuscular diseases, the mechanical coupling between muscle activation and rib cage motion may be further distorted. Although the abdominal contribution gives only an indirect index of diaphragm function, more direct measurements such as transdiaphragmatic pressure were avoided in this study to minimize instrumentation of these subjects. Despite these limitations, however, the mean abdominal contributions of our subjects in wakefulness and sleep were well below normal and their relationship in these patients to oxygen desaturation in REM sleep underlines the importance of diaphragm dysfunction in their vulnerability to sleep desaturation. The similarity between the fall in bilateral diaphragm paralysis in dogs lends further support to this view. Read the rest of this entry »

Ventilation and Breathing Pattern during Sleep in Duchenne Muscular Dystrophy: Outcome

Sampling problems are inevitable when selecting representative data from each sleep stage, particularly from periods of wakefulness and REM sleep. The heterogeneous nature of stage REM, comprising tonic and phasic components and often, in these subjects, brief arousal periods associated with oxygen desaturation, further limits interpretation of its ventilatory data. The heterogeneity is reflected in the measured coefficient of variation of all our measurements and is also seen in normal subjects. There have been several attempts to quantify ventilation and its components in normal subjects nonin-vasively during wakefulness and sleep. The RIP data of Stradling et al were obtained by MLR from restrained sleeping adult healthy males and so offer an appropriate comparison to the present results. Patients with Duchenne MD have severe generalized respiratory weakness usually without selective diaphragm involvement and, in our subjects, without obesity or significant scoliosis. Here Read the rest of this entry »

Ventilation and Breathing Pattern during Sleep in Duchenne Muscular Dystrophy: Discussion

Ventilation and Breathing Pattern during Sleep in Duchenne Muscular Dystrophy: DiscussionIn a further report that included data from four of these six subjects, we showed that mean hypopnea and apnea duration (usually REM related) was prolonged by oxygen treatment. In the present study, however, mean Ve in REM sleep was similar on air and oxygen. Representative mean data obtained over six to ten minutes of each sleep stage give an overall picture of Ve rather than an analysis of individual disordered breathing events; minor differences between air and oxygen nights may have been obscured. Nevertheless, it is reassuring that oxygen desaturation can be greatly improved or abolished without an apparent adverse effect on overall ventilation. Here Read the rest of this entry »

Ventilation and Breathing Pattern during Sleep in Duchenne Muscular Dystrophy: Comparison to Normal Values

Variability of Data
The within-subject coefficient of variation values were similar on air and oxygen and only those from air are given in Table 2. A marked increase in variability of all respiratory measurements occurred in changing NREM to REM sleep, but especially in the frequency of ventilation, and all save Vt and AC were more variable in REM than wakefulness.
Comparison to Normal Values
A comparison with normal data, derived using similar MLR calibration of RIP in six restrained young healthy adult males, is presented in Figure 3. This illustrates the mean values of each variable during wakefulness, slow wave (S3/4) sleep, and REM sleep in the six subjects with Duchenne MD studied on air compared to these published normal data. Significant differences between the present data and those of Stradling et al were noted for Ve in NREM sleep (p<0.05) and abdominal contribution during wakefulness (p<0.01), slow wave sleep (p<0.01), and REM sleep (p<0.05). Mean Vt/Ti fell by 17.8 percent (air) and 20.9 percent (oxygen) from awake to NREM sleep, but by only 2.9 percent in the published normal results; the further fall from NREM to REM sleep was similar to normal. other Read the rest of this entry »

Ventilation and Breathing Pattern during Sleep in Duchenne Muscular Dystrophy: Results

Ventilation and Breathing Pattern during Sleep in Duchenne Muscular Dystrophy: ResultsData Analysis
Data from six to ten representative consecutive minutes of wakefulness, steady stage 2 non-REM (NREM) sleep (S2), stage 3/4 NREM (S3/4), and REM sleep were obtained for both air and oxygen nights and a mean ± SEM derived. The “minute to minute” within-subject coefficient of variation for each sleep stage was also derived from these data. Comparisons between means were made using the Student t test. life without allergy com
Results
Daytime Pulmonary Function

The mean seated vital capacity of the six subjects was 1.48 L (range, 0.8 to 3.0 L) with a mean fall of 6.7 ( — 3.3 to 20 percent) when supine. The mean total lung capacity was 3.56 L (2.5 to 6.3 L). Residual volume ranged from 1.2 to 3.8 L (mean, 2.18 L) and functional residual capacity from 1.5 to 4.3 L (mean, 2.5 L). Maximum static mouth pressures were low in all subjects, the mean MIP being 37.5 (25 to 65 cm H20) and MEP being 29.2 (15 to 50 cm H20). Daytime blood gas tensions, however, were within normal limits (mean Po2, 14.5 kPa [13.2 to 17.9 kPa]; Pco2, 5.23 kPa [4.7 to 6.05 kPa]). Read the rest of this entry »

Ventilation and Breathing Pattern during Sleep in Duchenne Muscular Dystrophy: RIP Calibration

RIP Calibration
“Respibands” were taped securely to the chest (nipple level) and abdomen (umbilical level and below the costal margins). Immediately before “lights out” and with the patient in his preferred sleeping posture and prepared to sleep, volume-motion (VM) coefficients were obtained using computerized multiple linear regression (MLR) analysis as described by Stradling et al.s Briefly, RIP outputs from rib cage (RC) and abdomen (AB) together with the integrated spirometer signal (SP) from a pneumotachograph (Gould Godart BV) previously stabilized to eliminate drift and calibrated against a liter syringe were sampled within 20 ms of each other 150 times during a 20-second fixed period of quiet tidal breathing and were analyzed by MLR using a BBC “B” microcomputer programmed in Basic. The 150 raw data values for RC, AB, and SP were used in each calibration to calculate the VM coefficients (a and b), using the equation described by Armitage, te, (ax RC) + (bx AB) + e = SP (“e” representing errors arising from (1) the different voltages of the three variables, and (2) the offset attributable to the intercept of the plot of RIP volume: spirometer volume). more Read the rest of this entry »

Ventilation and Breathing Pattern during Sleep in Duchenne Muscular Dystrophy

Ventilation and Breathing Pattern during Sleep in Duchenne Muscular DystrophyWe have shown previously that recurrent episodes of central hypopnea and/or apnea with accompanying hypoxemia are common in subjects with advanced Duchenne muscular dystrophy (MD) during rapid eye movement (REM) sleep. There are, however, few reports quantifying the breathing pattern during wakefulness and sleep in patients with respiratory muscle weakness; such data can be obtained noninvasively using respiratory inductance plethysmography (RIP) that should help to characterize further the disordered breathing in sleep seen in subjects with Duchenne MD. In addition, the analysis of rib cage and abdominal contributions to breathing during wakefulness and sleep may shed light on the role of diaphragm dysfunction in the mechanism of REM-related oxygen desaturation in Duchenne MD. Acpurate and stable quantification of RIP data requires the subject to maintain a single posture and the equipment to be recalibrated following body movement. During sleep, therefore, reliable quantification is possible only for stationary or paralyzed subjects. Patients with advanced Duchenne MD are capable of only minimal body movement and require assistance to change their sleeping posture; they are thus ideally suited to RIP data analysis. We present ventilatory data obtained during overnight polysomnography from six acclimatized subjects with Duchenne MD randomized to air or oxygen on two consecutive nights. buy mircette birth control Read the rest of this entry »

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