首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Obstructive sleep apnoea (OSA) is associated with high cardiovascular morbidity and mortality. Several randomised controlled trials have shown that continuous positive airway pressure (CPAP) treatment of OSA reduces blood pressure (BP). This randomised, sham-placebo controlled crossover trial assesses whether CPAP produces a similar clinically significant fall in BP in hypertensive OSA patients, but without hypersomnolence. Thirty-five, nonsleepy, hypertensive patients with OSA were treated with CPAP for 1 month, randomised first to either therapeutic or sham-placebo (subtherapeutic CPAP, about 1 cmH(2)O pressure). The second months' alternative treatment followed a 2-week washout period. BP was measured over 24 h, before and at the end of the two treatment periods: mean 24-h BP was the primary outcome variable. There was no overall significant difference in mean 24-h BP: the change in mean 24-h BP on therapeutic CPAP was -2.1 mmHg (sd 8.1), and -1.1 mmHg (sd 8.1) on subtherapeutic CPAP, with a difference of 0.7 mmHg (95% confidence interval (CI) +2.9- -4.4). There was a small significant fall in Epworth Sleepiness Score, therapeutic (-1.4) versus sham (-0.3), and difference -1.2 (95% CI -2.0- -0.4), but no change in objective sleepiness. In nonhypersomnolent hypertensive patients with obstructive sleep apnoea, there is no significant fall in mean 24-h blood pressure with continuous positive airway pressure, in contrast to the fall seen in hypersomnolent patients with obstructive sleep apnoea.  相似文献   

3.
BACKGROUND: It was shown in normals that an important decrease in upper airway resistance can be obtained with continuous positive airway pressure (CPAP). It was suggested that lung inflation in patients with sleep apnea syndrome (SAS) could also be a mechanism of action of CPAP. OBJECTIVE: In the present study we wanted to evaluate the effects of nocturnal CPAP on the daytime lung function pattern in patients with SAS. METHODS: We measured arterial blood gases and possible changes in static lung volumes in 57 SAS patients (37 with normal lung function, 10 with COPD and 10 with restrictive lung disease) after at least one month of CPAP therapy. RESULTS: A significant increase in PaO(2) (from 79 to 84 mm Hg, p = 0.01) and a decrease in AaDO(2) (from 23 +/- 1 to 16 +/- 1, p < 0.01) was only observed in SAS patients with normal lung function. This improved gas exchange was parallelled by a small but non significant change in the FRC (from 96.5 +/- 3.2 to 105.4 +/- 3.7%pred, p = 0.07) and TLC (from 101.3 +/- 1.7 to 104.1 +/- 1.4%pred, p = 0.15). Similar changes in TLC and FRC were also observed in SAS patients with obstructive and restrictive lung disease. CONCLUSIONS: Chronic nocturnal CPAP therapy can improve daytime gas exchange and may influence lung inflation during the daytime. The small changes seem to be a functional effect but of no clinical relevance.  相似文献   

4.
Progressive neuromuscular symptoms years after recovery from acute paralytic poliomyelitis have been termed the PPS. We describe a 52-year-old man who contracted poliomyelitis at age 9 years who fully recovered and 33 years later developed progressive dyspnea. Neurologic evaluation revealed bilateral paralysis of the vocal cords, generalized weakness, and accentuated mouth occlusion pressure and ventilatory responses to hypercapnic, hyperoxic breathing. An EMG and muscle biopsy showed changes consistent with acute and chronic denervation. Cardiopulmonary exercise evaluation demonstrated a pulmonary mechanical limit with excessive ventilation relative to CO2 output. Tracheostomy and nocturnal positive pressure ventilation resulted in increased respiratory muscle strength, normalization of ventilatory drive and marked improvement in exercise capacity.  相似文献   

5.
目的探讨夜间无创正压通气(NPPV)治疗AECOPD合并Ⅱ型呼吸衰竭患者的临床疗效。方法选择82例AE-COPD合并Ⅱ型呼吸衰竭住院患者,随机分为夜间通气组(A组)、日间通气组(B组),治疗前及治疗后3 d、7 d清晨分别抽取动脉血查血气分析,比较治疗前后两组患者动脉血气分析变化。结果两组在治疗后血气分析各项指标较治疗前有明显改善,比较有显著差异(P〈0.05)。两组间治疗后比较A组PH、PaO2较B组明显升高,PaCO2明显降低,有显著差异(P〈0.05)。结论夜间NPPV治疗AECOPD合并Ⅱ型呼吸衰竭患者能较快改善患者血气分析指标及预后,长期应用有望提高患者生活质量。  相似文献   

6.
Excessive nocturnal diuresis and natriuresis have been reported in patients with sleep apnea. The mechanisms responsible for these alternations in nocturnal renal function have not been clearly identified. To gain further insight into this matter, we studied 12 patients (one woman) with a mean +/- SD age of 50 +/- 9 yr and body mass index of 36.9 +/- 8.6 kg/m2. Polysomnography showed in all a sleep apnea syndrome with an apnea-hyponea index (AHI) of 81.3 +/- 41.7. Treatment with nasal continuous positive airway pressure (nCPAP) resulted in an AHI of 19.4 +/- 13.7 and in normalization of sleep characteristics. Diurnal renal function was normal in all subjects. Although untreated, patients showed an abolition of the well-known decrease in diuresis and natriuresis during the night (diurnal and nocturnal diuresis 56.3 +/- 26.8 and 77.2 +/- 33.4 ml/h, respectively, p = NS; diurnal and nocturnal fractional urinary Na+ excretion 0.42 +/- 0.09 and 0.70 +/- 0.55 ml/100 ml glomerular filtration [GF], respectively, p = NS). Results of nocturnal studies under nCPAP therapy showed a significant decrease in diuresis and natriuresis (nocturnal diuresis before and under nCPAP, respectively: 90.4 +/- 27.3 and 70.6 +/- 25.1 ml/h, p less than 0.02; nocturnal fractional urinary sodium excretion before and under nCPAP, respectively: 0.76 +/- 0.53 and 0.44 +/- 0.37 ml/100 ml GF, p less than 0.03). Morning blood levels of renin, aldosterone, antidiuretic hormone, epinephrine, and atrial natriuretic factor showed no significant difference before and under nCPAP, whereas norepinephrine significantly decreased from 309.5 +/- 104.2 before to 230.4 +/- 88.4 pg/ml under nCPAP (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

7.
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.  相似文献   

8.
The improvement in arterial blood gas tensions following assisted ventilation in chronic obstructive pulmonary disease (COPD) has usually been attributed to the relief of incipient or established respiratory muscle fatigue. The contribution of changes in the load placed upon and the drive to the respiratory muscle pump have not been evaluated. We have investigated the contribution of changes in respiratory muscle strength, the ventilatory response to CO2 and ventilatory function to changes in arterial blood gas tensions in eight patients with severe COPD completing six months domiciliary nasal intermittent positive pressure ventilation. Six patients showed a reduction and two an increase in arterial carbon dioxide tension (PaCO2), median (range) for eight patients, -0.9 kPa (-1.5 to +0.4) (p less than 0.05) and seven showed an improvement in arterial oxygen tension (PaO2), +0.7 kPa (-0.4 to +1.7) (p less than 0.05) during daytime spontaneous breathing. The reduction in PaCO2 was not related to increased inspiratory muscle strength but was correlated with a decrease in gas trapping (Spearman rank correlation coefficient (r(S)) 0.85, p less than 0.05) and in the residual volume (r(s) 0.78, p less than 0.05), suggesting reduced small airway obstruction and, therefore, a reduction in load. The change in PaCO2 also correlated with the increase in ventilation at an end-tidal CO2 of 8 kPa during rebreathing (r(s) -0.76, p less than 0.05) suggesting improved chemosensitivity to CO2. Our data do not support the hypothesis that improvements were due to the relief of muscle fatigue. We suggest that the contribution of changes in load and central drive warrant further investigation.  相似文献   

9.
Continuous positive airway pressure (CPAP) remains the best treatment for sleep apnoea syndrome (SAS). In the 1990s, many authors reported on daily compliance, but all of the studies utilised relatively short periods of follow-up that did not exceed a few years. The mean annual rate of CPAP use in patients with SAS was prospectively recorded. In the current study, the results are presented along with compliance data from patients who started CPAP between 1991 and 1998 and were still using it by the end of 2003. The cohort was chosen in order to obtain >or=5 yrs of follow-up for each patient. In total, there were 204 patients. For the whole group, mean+/-sd compliance reached 321+/-90 and 393+/-84 min after 1 and 10 yrs, respectively. There was no significant change in the first 2 yrs, with a significant increase from the third year onwards. Compliance, or its evolution over time, was not correlated either to the baseline polysomnographical data (except slightly for the CPAP pressure), to the difference of these data before and under CPAP therapy, to the age of retirement or to changes in the marital status. In conclusion, very long-term compliance with continuous positive airway pressure increases by a mean of 8 min.day-1 per year of follow-up in patients with sleep apnoea syndrome.  相似文献   

10.
BACKGROUND: The long-term daily use of noninvasive mechanical ventilation (NIMV) to treat chronic respiratory failure in chronic obstructive pulmonary disease (COPD) patients is not widely recommended, partly because of a lack of clear clinical results and partly because the physiological mechanisms by which the daily application of NIMV would be helpful in these patients have not yet been clarified. OBJECTIVES: We designed a physiological study in order to assess the effects of supervised long-term NIMV on gas exchange, respiratory muscle function, pulmonary mechanics and to ascertain the possible effect of the treatment in responders and nonresponders. METHODS: Fourteen consecutive inpatients with stable hypercapnic COPD (pH = 7.37 +/- 0.01; PaCO(2) = 56.73 +/- 6.48 mm Hg) underwent 4 weeks of nocturnal NIMV delivered with a bilevel ventilator 'physiologically' set to reduce tidal transdiaphragmatic pressure (Pdi) by at least 50% and the amount of dynamic intrinsic positive end-expiratory pressure by 70%. Various measurements were compared with those obtained in a control group of consecutive patients with comparable baseline characteristics who refused NIMV and underwent breathing exercises for the same period of time. RESULTS: By the end of the 4 weeks NIMV had induced a slight but significant (p < 0.01) reduction in resting PaCO(2) (53.78 +/- 5.64 mm Hg) associated with a decrease in the pressure time product of the diaphragm per minute (from 172 +/- 60 to 136 +/- 61 cm H(2)O/l/s; p < 0.05). This latter value was primarily due to a significant shortening of the inspiratory duty cycle, while Pdi and lung mechanics were not modified. Eight of the 13 NIMV-treated patients (1 dropped out for nonmedical reasons) had a clear reduction in PaCO(2) (>3 mm Hg or >5% from enrollment) and were classified as responders. The acute reduction in PaCO(2) during the first trial with NIMV resulted to be a strong index of the final response. The subgroup of responders had a significantly increased maximal Pdi (from 41 +/- 19 to 49 +/- 23 cm H(2)O, p < 0.05) and an enhanced ability of the ventilatory pump to clear CO(2) (9.7 +/- 3.4 vs. 7.2 +/- 2.9 cm H(2)O x s/min; p < 0.01). No significant changes were observed in the control group. CONCLUSIONS: These results suggest that in a remarkable and identifyable proportion of patients with stable hypercapnic COPD, nocturnal NIMV may decrease resting PaCO(2), reraising the role of chronically supporting the respiratory pump.  相似文献   

11.
Noninvasive positive pressure ventilation (NIPPV) is widely used in the domiciliary treatment of chronic ventilatory failure. We conducted a multicenter, prospective study of the effects of NIPPV on blood gas levels, subjective symptoms, and the performance of daily activities. Fifty-one hospitalized patients with chronic ventilatory failure were enrolled in the study. Using NIPPV, 44 patients were able to live at home for more than 1 month, and 43 for more than 3 months. PaO2 and PaCO2 were 69.1 +/- 13.1 Torr (n = 25) and 70.8 +/- 11.0 Torr (n = 27) before NIPPV and 77.9 +/- 12.5 Torr (n = 26) and 61.0 +/- 11.2 Torr (n = 27) after 1 month of domiciliary treatment, respectively. Blood gas values were significantly improved after NIPPV. Patients experienced alleviation of all subjective symptoms. Dyspnea when wearing clothes, walking on flat levels, or climbing stairs also subsided, and was significantly reduced during daily activities other than eating among those patients who needed any help in performing their activities prior to the initiation of NIPPV. We concluded that NIPPV is an effective and convenient means of domiciliary ventilation that can help patients achieve greater independence in daily life. NIPPV can be expected to play a central role in home respiratory care for patients with hypercapnic respiratory failure.  相似文献   

12.
We wished to assess the efficacy of inhaled salmeterol (SML; 50 micrograms b.i.d.) compared to a combination of slow-release theophylline and ketotifen p.o. (TK; T 300 mg+K 1 mg b.i.d.) for the treatment of nocturnal asthma. Ninety six patients with nocturnal asthma, (forced expiratory volume in one second (FEV1) 60-90% of predicted value, reversibility > or = 15%, at least two nocturnal awakenings per week) were eligible for a multicentre, double-blind, double-dummy cross-over study (14-day run-in, two successive 28-day treatment periods). Efficacy was assessed as success/failure, success being defined as the complete disappearance of nocturnal symptoms/awakening during the last week of each treatment period. There was a statistically significant difference between SML and TK for this criterion: 46% and 39% success with SML during periods I (first 28-day period) and II (following the cross-over), compared to only 15% and 26% with TK, respectively (p < 0.01). SML was also significantly better for the other criteria (lung function, rescue salbutamol intake during day and night). Side-effects were five times less frequent in SML-treated patients (p < 0.004). Efficacy and tolerance of SML were obviously far better than those of TK in patients with nocturnal asthma.  相似文献   

13.
Intermittent positive pressure ventilation (IPPB) is reported to improve lung compliance and decrease the work of breathing in subjects with kyphoscoliosis. These results suggest that IPPB may improve chest wall and lung compliance in patients with neuromuscular disease. We studied the short-term effects of IPPB on total respiratory system compliance in 14 subjects with neuromuscular disease. Seven were quadriplegics, and seven had muscular dystrophy. Vital capacity was reduced to 38 +/- 14 percent of the predicted normal values. Baseline measurements of total respiratory system compliance were 57 +/- 18 percent when compared to normal control values. After a 20 minute treatment of IPPB delivered with inspiratory pressures of 20 to 25 cm H2O that more than tripled resting tidal volume, there was no significant change in total respiratory system compliance in either group of patients. These findings indicate that patients with quadriplegia or muscular dystrophy do not derive immediate improvement in ventilatory mechanics from IPPB treatments.  相似文献   

14.
Individuals with obstructive sleep apnea syndrome (OSAS) are at high risk for cardiovascular morbidity and mortality. The effects of OSAS severity and nocturnal continuous positive airway pressure (CPAP) on daytime baroreflex sensitivity (BRS) and nitric oxide (NO) production were investigated in OSAS patients. Fifty-one consecutive males with OSAS and 29 age-matched healthy men underwent the Valsalva test and standard polysomnography. Patients with an apnea-hypopnea index (AHI) of >or=20 episodes per hour were randomized to receive CPAP treatment for 3 months (n=14) or no such treatment (n=19). The BRS index measured from the overshoot phase (phase IV) of the Valsalva maneuver and plasma NO concentration were significantly lower, whereas the AHI, oxygen desaturation time, arousal index, percentage of sleep stage 1, and systolic blood pressure were significantly greater, in patients with an AHI of >or=20/h than in those with an AHI of <20/h or in controls. The 24-h urinary excretion of norepinephrine was significantly reduced and the plasma NO concentration was significantly increased after one night of CPAP. The BRS index for phase IV and the Valsalva ratio were significantly increased in the CPAP group after the 3-month treatment period but remained unchanged in the non-CPAP group of OSAS patients. The daytime BRS index and NO production were thus inversely related to the severity of OSAS, and successful CPAP treatment improved these parameters in patients with moderate to severe OSAS. CPAP may therefore reduce the risk of cardiovascular complications due to endothelial dysfunction or increased sympathetic activity.  相似文献   

15.
Summary We report the efficacy of therapy over 5 years follow-up in 758 non-insulin-dependent diabetic patients in a prospective, randomised controlled study of therapy of mild hypertension. Patients were recruited who on antihypertensive therapy had systolic blood pressure over 150 mmHg or diastolic over 85 mmHg, or if not on therapy had systolic blood pressure over 160 mmHg or diastolic over 90 mmHg. Their mean blood pressure at entry to the study was 160/94 mmHg at a mean age of 57 years. They were allocated to tight control (aiming for systolic < 150/diastolic < 85 mmHg) or to less tight control (aiming for systolic < 180/ diastolic < 105 mmHg). The tight control group were allocated to primary therapy either with a beta blocker (atenolol) or with an antiotensin converting enzyme inhibitor (captopril), with addition of other agents as required. Over 5 years, the mean blood pressure in the tight control group was significantly lower (143/82 vs 154/88 mmHg, p < 0.001). No difference was seen between those allocated to atenolol or captopril. The proportion of patients requiring three or more antihypertensive therapies to maintain tight control in those allocated to atenolol or captopril increased from 16 and 15 %, respectively at 2 years to 25 and 26 %, respectively at 5 years, whereas in the less tight control group at 2 and 5 years only 5 and 7 %, respectively required three or more therapies. There was no difference in the incidence of side effects or hypoglycaemic episodes between those allocated to atenolol or captopril, but those allocated to atenolol increased their body weight by a mean of 2.3 kg compared with 0.5 kg in those allocated to captopril (p < 0.01). Allocation to atenolol was also associated with small increases in triglyceride, and decreases in LDL and HDL cholesterol, which are of uncertain clinical relevance. The study is continuing to determine whether the improved blood pressure control, which was obtained, will be beneficial in maintaining the health of patients by decreasing the incidence of major clinical complications, principally myocardial infarction and strokes, and microvascular complications, such as severe retinopathy requiring photocoagulation and deterioration of renal function. [Diabetologia (1996) 39: 1554–1561]  相似文献   

16.
Obstructive sleep apnea syndrome (OSAS) is recognized as one of the risk factors of hypertension and cardiovascular disorders. In the current study, we hypothesized that the hypoxic stress and oxidative stress caused by obstructive sleep apnea would increase circulating adrenomedullin (ADM) levels in untreated OSAS patients as compared to an age and body mass index (BMI)-matched control group and an age-matched, but normal-BMI control group. We further hypothesized that nasal continuous positive airway pressure (nCPAP) treatment may decrease OSAS-induced hypoxic stress, oxidative stress and ADM levels. To examine these hypotheses, we measured circulating ADM and reactive oxygen species (ROS) from leukocytes before and after nCPAP therapy in OSAS patients. The circulating levels of ADM and amount of ROS in untreated OSAS patients were significantly greater than those in the controls. No differences in ADM levels were found between the increased-BMI controls and normal-BMI controls. We observed that nCPAP treatment decreased sleep apneas, nocturnal oxyhemoglobin desaturation, the circulating ADM, and ROS production by leukocytes in OSAS patients. The ADM levels were associated with the magnitude of oxyhemoglobin desaturation rather than the number of sleep apneas. These observations suggest that nCPAP therapy could reduce OSAS-induced nocturnal hypoxemia, generation of ROS, and ADM in patients with OSAS.  相似文献   

17.
The purpose of the present study was to analyse the importance and prognostic value of renal failure in multiple myeloma patients. The frequency and reversibility of renal failure in 775 multiple myeloma patients diagnosed between 1984-86 and 1990-92 in the Nordic countries were studied. Renal failure, defined as plasma creatinine > 130 micromol/l, was observed in 29% of the cases at the time of diagnosis. During the first year after diagnosis 58% achieved normalisation of p-creatinine, and this was achieved mainly during the first 3 months. Reversibility of renal failure was more frequently observed in patients with moderate renal failure, hypercalcaemia and low Bence-Jones protein excretion. In a multivariate analysis renal failure, high age, stage III disease and hypercalcaemia were independent prognostic factors for survival. Patients who needed dialysis had a poor prognosis, with a median survival of 3.5 months. A 12-months landmark analysis showed that reversibility of renal failure was a more important prognostic factor than response to chemotherapy. It is concluded that renal failure in multiple myeloma is reversible in about half the cases, and reversibility of renal failure improves long-term survival.  相似文献   

18.
The effects of a new angiotensin receptor antagonist, eprosartan (200 or 300 mg b.i.d.) and enalapril (5-20 mg u.i.d.) on cough and blood pressure were compared in a 26-week, double-blind, randomised, parallel-group, multicentre, international study involving 528 patients with hypertension. Uptitration of doses was based on clinic blood pressure measurements during the first 12 weeks, after which hydrochlorothiazide (12.5-25 mg/day) could be added. The frequency and intensity of cough was assessed by a standardised questionnaire administered at each clinic visit. The primary end-point was the incidence of persistent, dry cough not due to upper respiratory infection; change in sitting diastolic blood pressure and overall incidence of cough were secondary end-points. During the first 12 weeks of double-blind therapy, enalapril treatment was associated with a 3.45-fold higher risk of definite cough (14/261 vs 4/259, P = 0.018). Overall cough incidence (from spontaneous reports from patients, or investigator's observation) was also more frequent with enalapril, as compared to eprosartan. Both agents reduced blood pressure significantly compared to baseline, although the eprosartan-treated group had a slightly higher response rate (defined as sitting diastolic blood pressure <90 mm Hg, or at least a 10 mm Hg reduction from baseline), both at end of titration (70.3% vs 62.6%, P < 0.05) and after 26 weeks (81.7% vs 73.5%, P= 0.018). These data suggest that, in unselected hypertensive patients, eprosartan is associated with less cough and a somewhat higher responder rate than enalapril.  相似文献   

19.
20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号