Exercise and noninvasive ventilatory support.

Breathlessness is the most common symptom that limits exercise in patients with chronic obstructive pulmonary disease and who may receive benefit from exercise training programmes. Exercise intensity may influence the physiological benefits of the programme. Although the exact underlying physiopathological mechanism is still unclear, there is laboratory evidence that continuous positive airway pressure and other modalities of mechanical ventilation (delivered either by mouthpiece or facial or nasal masks) may reduce breathlessness and increase exercise tolerance in these patients, in order to allow them to reach a higher exercise intensity.

Preliminary results on nursing workload in a dedicated weaning center.

Objective: To evaluate the nursing time required for difficult-to-wean patients in a dedicated weaning center (WC) and to examine the correlation of the nursing time with nursing workload (NW) scores and with clinical severity and dependency.

Setting: Four-bed WC of a pulmonary rehabilitation department.

Intervention: None.

Production of endogenous nitric oxide in chronic obstructive pulmonary disease and patients with cor pulmonale. Correlates with echo-Doppler assessment.

Exhaled nitric oxide (NO) production in stable chronic obstructive pulmonary disease (COPD) has been loosely related to the severity of illness, being significantly reduced in the most severe cases. Pulmonary hypertension is associated with lower NO output from the lung. In this study expired NO was measured in patients with severe stable COPD with or without cor pulmonale (CP).

Negative pressure ventilation vs external high-frequency oscillation during rigid bronchoscopy. A controlled randomized trial.

Study Objectives: To compare the effectiveness of two modalities of external ventilation during rigid bronchoscopy: intermittent negative pressure ventilation (INPV) and external high-frequency oscillation (EHFO).

Design: Prospective, controlled, randomized, nonblinded study.

Setting: University-affiliated hospital.

Physiologic effects of early administered mask proportional assist ventilation in patients with chronic obstructive pulmonary disease and acute respiratory failure.

Objective: To evaluate the physiologic short-term effects of noninvasive proportional assist ventilation (PAV) in patients with acute exacerbation of chronic obstructive pulmonary disease (COPD).

Design: Prospective, physiologic study.

Setting: Respiratory intermediate intensive care unit.

Long-term effectiveness of pulmonary rehabilitation in patients with chronic airway obstruction.

The aim of this study was to evaluate the long-term outcome of an outpatient pulmonary rehabilitation programme (PRP) in patients with chronic airway obstruction (CAO). In 61 CAO patients (35 asthmatics and 26 chronic obstructive pulmonary disease (COPD)) lung and respiratory muscle function, exercise tolerance (by symptom limited cycloergometer and walking tests), dyspnoea (Borg scale, visual analogue scale (VAS), baseline and transitional dyspnoea index (BDI and TDI, respectively)) and quality of life (St George's Respiratory Questionnaire (SGRQ)) were assessed at baseline (to), at discharge (t1) and 12 months postdischarge (t2). Preprogramme and post-programme hospital admissions and exacerbations of disease were also recorded.

Effects of oxygen on autonomic nervous system dysfunction in patients with chronic obstructive pulmonary disease.

Chronic hypoxaemia can play a pathological role in abnormalities of the autonomic nervous system (ANS). In patients with chronic obstructive pulmonary disease (COPD), chronic hypoxaemia is associated with increased mortality and only long-term oxygen therapy is able to improve their survival. Normoxaemic COPD patients have been shown to suffer from abnormalities in ANS function.

Endogenous nitric oxide in patients with chronic heart failure (CHF): relation to functional impairment and nitrate-containing therapies.

We assessed the levels of exhaled nitric oxide (eNO) in patients with chronic heart failure (CHF) according to the functional impairment and the use of nitrate-containing agents. Forty patients (age 55+/-9 years) were classified according to the NYHA classes I-II (n=18, group 1) and classes III-IV (n=22, group 2), and to the use of nitrate-containing drugs (Nitrate+, Nitrate-). Twenty-two healthy age-related subjects served as controls (group 3).

Physiological and symptom determinants of exercise performance in patients with chronic airway obstruction.

To evaluate the physiological and symptom determinants of exercise performance (EP) as measured by a 6-min walking test (6MWD), Watt(max), and peak oxygen consumption (VO2 ml/min/kg), 105 patients with chronic airway obstruction (CAO) [50 chronic obstructive pulmonary disease (COPD): 44 men, aged 63+/-7 years, forced expiratory volume in 1 sec (FEV1) forced vital capacity (FVC)(-1)% 54+/-13; and 55 asthmatic: 23 men, aged 55+/-10 years, FEV1 FVC(-1) % 65+/-10] underwent evaluation of 6MWD, symptom limited cyclo-ergometer exercise test, spirometry, respiratory muscle function, arterial blood gases and sensation of dyspnoea [using the Borg scale, Visual Analogue Scale (VAS) and Baseline Dyspnoea Index (BDI)]. A hierarchical method of analysis identified the residual volume (RV), total lung capacity (TLC)(-1) ratio, BDI and the patient's age as the strongest and most consistent correlates of EP (r2 = 0.14-0.

Exhaled nitric oxide and exercise in stable COPD patients.

Study Objective: To evaluate exhaled nitric oxide (eNO) during exercise in patients with stable COPD.

Setting: Outpatient evaluation in a rehabilitation center.

Patients: Eleven consecutive male patients with stable COPD (age, 65 +/- 6 years; FEV(1), 56 +/- 10% predicted).

Physiological effects of posture on mask ventilation in awake stable chronic hypercapnic COPD patients.

Stable chronic hypercapnic patients are often prescribed long-term mask noninvasive pressure support ventilation (NPSV). There is a lack of information on the effects of posture on NPSV. Therefore posture induced changes in physiological effects of NPSV in awake stable chronic hypercapnic patients were evaluated.

Chest wall kinematics and respiratory muscle action in walking healthy humans.

We studied chest wall kinematics and respiratory muscle action in five untrained healthy men walking on a motor-driven treadmill at 2 and 4 miles/h with constant grade (0%). The chest wall volume (Vcw), assessed by using the ELITE system, was modeled as the sum of the volumes of the lung-apposed rib cage (Vrc,p), diaphragm-apposed rib cage (Vrc,a), and abdomen (Vab). Esophageal and gastric pressures were measured simultaneously.

Heart failure-related myopathy. Clinical and pathophysiological insights.

Aims: To evaluate the relationship of skeletal and respiratory muscular dysfunction with the degree of clinical severity, cardiac impairment and exercise intolerance in patients with chronic heart failure.

Methods And Results: Ninety-one patients (age 52.7+/-8 years) on standard therapy and in a stable clinical condition with normal nutritional status underwent evaluation of (1) clinical severity and metabolic status (NYHA class, weight, albuminaemia, natraemia, cortisol, insulin, neurohormones), (2) cardiac function (Echo, right heart catheterization), (3) exercise tolerance (peak VO(2)), (4) dynamic isokinetic forces of the quadriceps and hamstring (Cybex method), and respiratory muscle strength (maximal inspiratory and expiratory pressures).

Endogenous nitric oxide in patients with stable COPD: correlates with severity of disease.

Background: Increased levels of exhaled nitric oxide (eNO) have been reported in asthmatic subjects but little information is available on eNO in patients with advanced chronic obstructive pulmonary disease (COPD). A study was undertaken to evaluate the levels of eNO in patients with stable COPD of different degrees of severity.

Methods: Peak and plateau values of eNO (PNO and PLNO, respectively) were evaluated in 53 patients with COPD and analysed according to the level of forced expiratory volume in one second (FEV1) and the presence of cor pulmonale (CP) (group 1, FEV1 < 35% predicted with CP, n = 15; group 2, FEV1 < 35% predicted without CP, n = 15; group 3, FEV1 > 35% predicted, n = 23).

Detection of nitric oxide in exhaled air of different animal species using a clinical chemiluminescence analyser.

The aim of the present study was to evaluate the nitric oxide (NO) concentrations present in end-expired gas (FENO) of different animal species under basal and stimulated conditions using a clinical chemiluminescence analyser, which has been developed for measurement of single exhalations in humans. Anaesthetised, tracheotomised and artificially ventilated guinea pigs, rats and rabbits were prepared for recording systemic blood pressure and FENO. Stable levels of FENO were detected in expired air over a 1-h observation period in the three animal species tested.

Differences in spontaneous breathing pattern and mechanics in patients with severe COPD recovering from acute exacerbation.

The aims of this study were to assess spontaneous breathing patterns in patients with chronic obstructive pulmonary disease (COPD) recovering from acute exacerbation and to assess the relationship between different breathing patterns and clinical and functional parameters of respiratory impairment. Thirty-four COPD patients underwent assessment of lung function tests, arterial blood gases, haemodynamics, breathing pattern (respiratory frequency (fR), tidal volume (VT), inspiratory and expiratory time (tI and tE), duty cycle (tI/ttot), VT/tI) and mechanics (oesophageal pressure (Poes), work of breathing (WOB), pressure-time product and index, and dynamic intrinsic positive end-expiratory pressure (PEEPi,dyn)). According to the presence (group 1) or absence (group 2) of Poes swings during the expiratory phase (premature inspiration), 20 (59%) patients were included in group 1 and 14 (41%) in group 2.

Outcome of COPD patients performing nocturnal non-invasive mechanical ventilation.

The role of non-invasive nocturnal domiciliary ventilation (NNV) in chronic obstructive pulmonary disease (COPD) patients with chronic hypercapnia is still discussed. The aims of this study were to evaluate the long-term survival, the clinical effectiveness and side-effects of NNV in these patients. Forty-nine stable hypercapnic COPD patients on long-term oxygen therapy (LTOT) were assigned to two groups: in Group 1, 28 patients performed NNV by pressure support modality in addition to LTOT; in Group 2, 21 patients continued their usual LTOT regimen.

Noninvasive mechanical ventilation in the weaning of patients with respiratory failure due to chronic obstructive pulmonary disease. A randomized, controlled trial.

Background: In patients with acute exacerbations of chronic obstructive pulmonary disease, mechanical ventilation is often needed. The rate of weaning failure is high in these patients, and prolonged mechanical ventilation increases intubation-associated complications.

Objective: To determine whether noninvasive ventilation improves the outcome of weaning from invasive mechanical ventilation.

Dobutamine-induced changes in pulmonary artery pressure in patients with congestive heart failure and their relation to abnormalities of lung diffusing capacity.

Short-term infusion of dobutamine may determine a mild, statistically significant increase in pulmonary artery pressure from baseline in 30% of patients with moderate to severe heart failure despite systemic effects (changes in cardiac index and systemic vascular resistance) similar to those observed in patients showing a large reduction in right heart pressures. The increase in pulmonary artery pressure observed seems to be associated with a lower pulmonary diffusing capacity, probably reflecting a reduction in recruitment and distension capacity of pulmonary circulation.