Figure 1 illustrates a block diagram of the renal-body fluid volume mechanism for arterial pressure control.” Solid lines between successive blocks indicate that an increase in the factor in one block causes an increase also in the factor in the next block. Dashed lines indicate that an increase of the first factor causes the second factor to decrease. The function of this system is described in the following:
(I) An increase in arterial pressure increases the urinary volume output (blocks 1, 2).- This is a very marked effect, as will be illustrated by function curves in figures 6, 7, 8. That is, a very slight rise in arterial pressure is associated with a marked increase in kidney excretion of urine. It is this basic ability of urinary output to respond markedly to changes in arterial pressure that allow the renal-body fluid volume mechanism to control arterial pressure exactly.
We studied 1 female and 11 male COPD patients (mean ± SD; FEV1 40 ± 14% predicted; mean age, 69 ± 7 years) who were ex-smokers with a mean smoking history of 68 ± 23 pack-years (Table 1). All patients had negative results of skin-prick reaction tests and radioallergosorbent tests for a battery of common allergens. Patients’ exacerbation and stable-state characteristics are given in Table 1. A clear deterioration in cough, sputum, and blood gas analysis was observed in all subjects during an exacerbation. In addition, patients were unable to perform acceptable spirometry during an exacerbation. All patients showed acute respiratory failure at the time of the exacerbation (Po2, < 60 mm Hg) [Table 1]. Five patients had positive sputum culture results during exacerbations (for Streptococcus pneumoniae, three patients; for Pseudomonas aeruginosa, two patients). Chest radiographs at the time of exacerbation did not reveal pneumonia or pneumothorax in any patient.
Mean room air oxygen saturation was not significantly different for each delivery method. The mean respiratory rates were 16.2 ± 4.0 at rest and 19.5 ± 5.1 at the end of exercise. Oxygen saturation and the amount of oxygen required to produce adequate saturation each minute for all subjects, from each trial, using both oxygen delivery techniques, are shown in Table 2. All saturation readings were recorded at the end of the three minute exercise session. In most cases, both steady flow and the DODS were able to provide the subjects with enough oxygen to meet their physiologic needs during low-level exercise. However, much more oxygen was required using steady flow delivery than the DODS to achieve adequate oxygen saturation.
The performance curves of steady flow and DODS oxygen delivery are shown in Figure 2. At 90 percent saturation, the oxygen supply requirement was 211.4 ml/min for the DODS as contrasted to steady flow which was 1,610.9 ml/min. Therefore, the mean oxygen savings benefit of the DODS over steady flow delivery is 7.6:1 with a range of 3.95:1 (subject 6) to better than 10:1 (subject 3). These differences are statistically significant (p<.0001). A comparison of oxygen utilization at 90 percent saturation for each delivery method is shown in Figure 3. Again, substantially more oxygen is required using steady flow delivery, as opposed to DODS delivery, to achieve equivalent oxygen saturation.
The lung is a major target organ for smoking-related disease. Because of the risk of lung disease, smokers have been recommended to give up the habit, or failing that, to change to cigarettes with lower yields of tar, nicotine and carbon monoxide. While there is evidence that cessation of smoking results in a slow improvement in abnormal pulmonary function, we are unaware of any evidence of improvement in pulmonary function test results when smokers change to lower yield cigarettes. However, a difficulty with this type of study arises from the long time course required for improvement in conventional tests of lung function even after complete cessation of smoking.
The use of inspiratory muscle resistive loading training plus nonventilatory muscle exercise (particularly walking) while breathing oxygen improves exercise performance and endurance in COPD patients during ten-week outpatient therapy.
This 38-year-old caucasian woman had had yellow, pebbly skin lesions in the axillae (Fig 1), antecubital fossae (Fig 2) and around the neck since the age of six. She now presents with a several-year history of chest pain. Her only known risk factor for atherosclerosis is hypertension. Physical examination is notable for skin findings and angioid streaks in the fundi (Fig 3, arrows). What is the diagnosis?
b) cutis laxa
c) pseudoxanthoma elasticum
d) Ehlers-Danlos syndrome
Answer: The diagnosis is (c), pseudoxanthoma elasticum
In the present report, easy bruising averaged 7.6% in the ICS group and 3.6% in the placebo group among all participants. These findings are roughly similar to those reported from previously published randomized controlled trials of ICS in COPD pa-tients, in which the findings were not adjusted for compliance with the study drug. When results from the present study were stratified based on measured inhaler compliance, we observed that, among those who complied well with the use of their assigned inhaler, a larger proportion of the ICS group reported easy bruising (11.2%) than those of the placebo group (3.5%). Thus, the incidence of reported bruising was 3.2-fold higher in the ICS group than the placebo group when only good compliers are considered, as opposed to a 2.1-fold difference when all participants were included in the analysis. Failure to control for the effect of compliance, therefore, results in a substantial underestimate of the effect of ICS use on bruising. Continue reading
Weaknesses of the above-cited older studies are that they were cross-sectional, nonrandomized surveys and that they relied on retrospective reporting of previous, as well as current, ICS use. Moreover, some subjects had received oral corticosteroids in variable amounts at least in short courses, potentially contributing to the occurrence of cutaneous as well as other systemic side effects. More recently, the incidence of skin bruising has been examined in three large-scale, prospective, 2.5-year to 3-year, randomized controlled clinical trials of high-dose ICSs in the management of stable patients with COPD (Table 7). Bruising was assessed either by subjective self-reports of side effects or by the direct observation of ecchymotic areas > 5 cm2 in size on the volar side of the forearm. In two of these clinical trials, the proportion of subjects in whom bruising was found was numerically but not significantly higher in the ICS group than the placebo group (7.3% vs 4%, respectively, in one study; and 7% vs 6%, respectively, in the other study). In the third trial, the highest prevalence of bruises at any visit was significantly higher in the ICS arm than in the placebo arm (4.9% vs 1.4%, respectively). Continue reading
The relevance of these findings to potential cutaneous effects of other commonly used ICSs might be inferred from published data concerning the equi-systemic effects (ie, microgram dose producing equal systemic cortisol suppression) of six inhaled corticosteroid preparations. According to the latter report, TAA produces a systemic effect (10% cortisol suppression) that is equivalent to 1.43 times the microgram dose of beclomethasone chlorofluorocarbon (CFC). By comparison, flunisolide CFC, fluticasone dry powder inhaler, budesonide dry powder inhaler, and fluticasone metered-dose inhaler CFC produce systemic effects equivalent to that of 1.71, 0.81, 0.50, and 0.20 times the microgram dose of beclometha-sone CFC, respectively. Continue reading
Easy Bruising and Acetylsalicylic Acid/Nonsteroidal Anti-inflammatory Drug Use
Use of acetylsalicylic acid (ASA) or nonsteroidal anti-inflammatory drugs (NSAIDs) was reported by a slightly but significantly higher proportion of participants who also reported bruising (87.7%) than those who did not (78.8%; p = 0.001 [x2 test]). On the other hand, a higher proportion of those assigned to receive placebo than to receive TAA reported using ASA or NSAIDs, making it unlikely that ASA/NSAID use contributed to the association between ICS use and bruising. Continue reading