[Questionnaires for occupational disability evaluation in patients with chronic respiratory diseases]. / Questionari per la valutazione della disabilità occupazionale in pazienti con malattie respiratorie croniche.

Chronic Obstructive Pulmonary Disease (COPD) represents a model of respiratory degenerative chronic disabling disorder. In Pulmonary Rehabilitation (PR), occupational approach is aimed at restoring patient's abilities at best in the social, familiar and working scenarios, and it is an essential part of a good PR Programme. To evaluate first occupational disability and then the occupational outcome of a PR programme, we need appropriate tools. London Chest Activity of Daily Living (LCADL) ed il Manchester Respiratory Activities of Daily Living (MRADL) are two questionnaires with such characteristics available in the literature. Our aim was to translate into Italian and adapt to the Italian social reality these two questionnaires. This may be a preliminary albeit necessary step to obtain reliable data on the occupational outcome of PR programmes in Italy.

Quality of generated diagnosis related groups in Italian Respiratory Intermediate Care Units.

BACKGROUND: To date we lack official data on tipology of Diagnosis Related Groups (DRGs) and their quality in Italian Respiratory Intermediate Care Units (RICUs). AIM: The objective of the study was to collect data on the activity of 26 Italian RICUs and to evaluate the quality of the DRGs generated. METHODS: The primary and secondary diseases, the procedures carried out and their coding using the ICD9 system (valid Italy until 2000) were collected from the discharge forms of patients admitted to RICUs. To obtain the DRG, these codes were automatically recoded in the ICD9-CM classification system by Grouper 10. Afterwards, the same diseases and procedures were directly processed by the ICD9-CM classification system. Finally, in order to evaluate the quality of care, the DRGs generated by the ICD9 classification system were compared to DRGs generated by the ICD9-CM classification system. RESULTS: The average weight of the patients cared for in an Italian RICU was 2.05 using the ICD9 classification system and 2.53 using the ICD9-CM classification system. Some non-complicated DRGs (80-97) or non specific DRGs (101-102) were set to zero; others, like DRG 87 appear due to the ability of the ICD9-CM classification system to recognise and accept the fifth digit of the Respiratory Failure code (518.81). The difference in terms of DRG scores generated by the two codification systems was 360.5 DRG points in favour of ICD9-CM. More than 1 million Euro of reimbursements have been lost, as the average national reimbursement for each DRG score is Euro 2,943.80. CONCLUSION: Severe pulmonary diseases determined the case mix of patients cared for in the Italian RICUs during the observed period. The Italian RICUs offer high quality assistance and are characterised by high mean weight per treated patient. However, the activity has been under-estimated due to the low sensitivity of the ICD9 classification system used in the recognition of the real disease and in the correct generation of relative DRG. The ICD9 classification system penalised the recognition of respiratory failure in particular.

Use of bronchodilators during non-invasive mechanical ventilation.

Bronchodilators represent one of the most important therapeutic weapons for the treatment of airway obstructive diseases and the inhaled route of administration is very often employed due to the greater drug availability and reduced magnitude of side effects. During acute exhacerbations, it is not unfrequent that the elastic and resistive loads imposed on the ventilatory pump overcome the force sustainable by the respiratory muscles and the patient requires ventilatory assistance, in order to relieve fatigue and to optimize alveolar gas exchange. During these episodes, inhaled bronchodilators, far from being discontinued, sometime must be administered during mechanical ventilation, that, in hypercapnic ventilatory failure can be frequently applied noninvasively with a good rate of success. While in the current literature there are a lot of data about inhaled drug administration during invasive mechanical ventilation, very few data are available on the topic of aerosol therapy during noninvasive mechanical ventilation. With the present paper we want to analyze the rationale, the feasibility and the current data dealing with the administration of inhaled drugs during noninvasive mechanical ventilation.

Salbutamol delivery during non-invasive mechanical ventilation in patients with chronic obstructive pulmonary disease: a randomized, controlled study.

OBJECTIVE: We investigated the clinical response to equivalent doses of salbutamol delivered, via metered dose inhaler (MDI) during non-invasive mechanical ventilation (NIMV-MDI), during spontaneous breathing using a spacer (MDI-Spacer), and also during intermittent positive pressure breathing (IPPB). SETTING: A respiratory intensive care unit. DESIGN: Prospective, randomized, and placebo-controlled study. PATIENTS: Eighteen stable patients with chronic obstructive pulmonary disease (mean FEV1=38.5+/-8.8% predicted). RESULTS: Overall salbutamol administration induced, compared to placebo, a significant improvement in FEV1, irrespective of the mode of administration (+7.9+/-7.1% or +108+/-91 ml for IPPB, +9.6+/-8.8% or 112+/-67 ml for MDI-NIMV (inspiratory pressure=14.3+/-1.8 cmH2O; expiratory pressure=none), and +10.8+/-11.4% or 119+/-114 ml for MDI-Spacer, respectively). DeltaFVC significantly increased from placebo only in MDI-NIMV (+214+/-182 ml P=0.02). A second set of experiments performed in eight patients to ascertain the possible effect of NIMV on pulmonary function tests, showed a significant improvement from baseline values in FVC both after the delivering of placebo or salbutamol via NIMV-MDI (+206+/-147 ml and 208+/-145, respectively). FEV1 significantly increased only after salbutamol. No changes in gas exchange were observed after bronchodilator delivery. CONCLUSIONS: We show that delivery of bronchodilators via MDI with a spacer chamber during NIMV is feasible and induces a significant bronchodilator effect compared to placebo, even though it may be slightly less effective than the classical delivery system (MDI-Spacer).

Physiological response to pressure support ventilation delivered before and after extubation in patients not capable of totally spontaneous autonomous breathing.

We designed a prospective, physiological study in 12 patients affected by chronic respiratory disorders. The study was aimed at assessing the diaphragm energy expenditure (PTPdi), lung resistance (RL) and elastance (EL), arterial blood gases (ABG), breathing pattern, and dyspnea measured by a visual analog scale during invasive pressure support ventilation (i-PSV) and noninvasive PSV (n-PSV). The ventilator settings were kept the same. Both i-PSV and n-PSV significantly reduced the PTPdi per minute, compared with that during a T-piece trial (204.4 +/- 93.8 cm H(2)O x s/min [i-PSV]; 197.5 +/- 119.8 [n-PSV]; 393.8 +/- 129.0 [T-piece]). Expired tidal volume (VTe) was significantly higher (p < 0.05) during n-PSV (615 +/- 166 ml) than during i-PSV (519 +/- 140 ml). The respiratory pump (PTPdi/VTe) was more effective (p < 0.05) with noninvasive ventilation (22.3 +/- 2.3 cm H(2)O x s/L for i-PSV versus 17.2 +/- 3.3 for n-PSV). RL and EL were similar with the two modes of ventilation. Overall dyspnea was significantly (p < 0.05) better during n-PSV than i-PSV, whereas ABG were similar. We have shown, in patients affected by stable chronic respiratory disorders not ready to sustain totally spontaneous breathing, that i-PSV and n-PSV are equally effective in reducing the PTPdi and in improving ABG, but that n-PSV seems to be better tolerated.

Reliability of a questionnaire for evaluating the understanding of asthma.

The present study was designed to evaluate the repeatability of a questionnaire developed to assess the understanding that asthma patients have of their disease and, on the basis of its variability, estimate the sample size necessary for determining the efficacy of a future structured program on asthma knowledge. The repeatability of the Asthma Questionnaire (AQ) was evaluated by asking 89 patients to complete it twice within a period of 7-10 days without the subject being exposed to any programme on asthma knowledge between the two administrations. The AQ was demonstrated to have good content and face validity. Results showed that neither age nor sex had a significant influence on total scores, and that the degree of reliability was adequate (R = 0.769). The mean percentage of correct answers was observed to be approximately 70% in both sessions, suggesting a consistent area for possible improvement which could be targeted by means of an appropriately structured programme on asthma knowledge. For comparative purposes before and after the programme, or for measuring its efficacy, the AQ should be recommended. In conclusion the Asthma Questionnaire could provide a useful tool for the general practitioner, chest physician and other health professionals, to assess what the patient really does understand or does not, concerning asthma management, and hence be the starting point for a well-tailored educational intervention.

Erectile dysfunction in men with obstructive sleep apnea: an early sign of nerve involvement.

Erectile dysfunction (ED) is common in men with obstructive sleep apnea (OSAS) but no completely convincing hypotheses about the underlying pathogenic mechanisms have been published in the literature. The aims of the present study were to assess the presence of ED in a group of OSAS patients without daytime respiratory failure and to determine whether this dysfunction was related to peripheral nerve involvement. Evaluation of the bulbocavernosus reflex (BCR) and the somato-sensory evoked potentials of pudendal nerve (PSEPs), the most widely established method of documenting pudendal neuropathies as being the cause of impotence, was performed in 25 patients. Data on BCR were compared with those of 25 healthy males volunteers matched for age. BCR was altered in 17 patients: in 6 it was elicited while in 11 it had a prolonged latency and reduced amplitude. Patients with altered BCR presented an higher AHI, an higher percentage of sleep time spent with SaO2 <90% (TST90) and a lower daytime PaO2. Six patient had clinically silent neurophysiological signs of mild polyneuropathy. The degree of OSAS and gas exchange alteration was more severe in patients with polyneuropathy than in those with isolated BCR alteration. ED is a common finding in OSAS patients and this alteration seems to be related to a nerve dysfunction. The development of nerve dysfunction is associated with a more severe degree of OSAS and nocturnal hypoxia.

Pulmonary function and complications following chemotherapy and stem cell support in breast cancer.

Pulmonary complications are frequent in patients treated with high-dose chemotherapy and autologous bone marrow transplantation for breast cancer or other solid tumours. This study analyses the development of lung toxicity, changes in respiratory function and occurrence of clinical symptoms in a group of 24 patients (mean age 46+/-7 yrs) who underwent high-dose sequential chemotherapy (HDS) with autologous peripheral blood stem cell (PBSC) support for high risk breast cancer. Clinical examination, chest radiography and lung function tests were performed before the HDS and 1 and 3 months following transplantation. Only one patient developed acute interstitial pulmonary disease which resolved after prednisone therapy. No patients developed infectious complications after transplantation. Baseline respiratory function was normal for most of the parameters. Only lung diffusing capacity of the lung for carbon monoxide (TL,CO) and maximal inspiratory pressure were below the normal range. Following PBSC transplantation only one patient had an altered vital capacity while 72.3% of patients had reduced TL,CO values at 1 month and 54.5% at 3 months after transplantation. Maximal expiratory flow at 25% forced vital capacity, TL,CO and maximal expiratory pres-sure were significantly reduced after 1 month but recovered slightly by 3 months. Arterial oxygen tension between baseline and both follow-up evaluations declined significantly in patients seropositive for human cytomegalovirus. It is concluded that this high-dose sequential chemotherapy regimen is acceptably safe since no pulmonary related mortality or respiratory infectious complications were observed. The only lung function alteration induced was an isolated diffusing capacity of the lung for carbon monoxide impairment, clinically negligible and partially recovered within 3 months.

Identification of chronic heart failure patients at risk of Cheyne-Stokes respiration.

Chronic heart failure (CHF) patients frequently show sleep-disordered breathing consisting of periodic breathing (PB) and Cheyne-Stokes respiration (CSR) with central sleep apnoea (CSA). Since the diagnosis of sleep-disordered breathing, in CHF patients, can be made only by means of full polysomnography, the aim of the present study was to evaluate whether or not daytime respiratory function can identify patients at risk of nocturnal PB and/or CSR/CSA. Twenty-seven patients (mean age 54 +/- 8.5 yrs), eight New York Heart Association Functional Class (NYHAFC) II, 17 NYHAFC III and two NYHAFC IV, with severe cardiac failure (cardiac output 2.0 +/- 0.66 L.min-1, ejection fraction 22.5 +/- 5.77%, pulmonary capillary wedge/pressure 23 +/- 9.05 mmHg). Mouth occlusion pressure (P0.1)/maximal inspiratory pressure (MIP) was significantly higher in patients with nocturnal CSR/CSA (5.04 +/- 1.49 versus 3.24 +/- 2.13%, analysis of variance (ANOVA) 0.03), whereas their arterial carbon dioxide tension (Pa,CO2) was significantly lower (4.15 +/- 0.56 (31.2 +/- 4.23 mmHg) versus 4.67 +/- 0.53 kPa (35.1 +/- 4 mmHg), ANOVA 0.02). Logistic regression analysis demonstrated that CSR/CSA occurrence may be predicted by daytime measurement of P0.1/MIP and Pa,CO2 (p = 0.04 and 0.01 respectively; odds ratio 1.93 and 0.76 respectively). The sensitivity was 70%, specificity 76.5%, false positive rate 36.4%, false negative rate 18.8%, positive predictive value 71.4% and negative predictive value 85%. This model seems useful for predicting respiratory pattern changes in chronic heart failure patients and the authors suggest that polysomnography be performed only in high-risk patients, saving costs and the resources of sleep laboratories.

The development of hyperventilation in patients with chronic heart failure and Cheyne-Strokes respiration: a possible role of chronic hypoxia.

AIM: To analyze the relationship between daytime respiratory and cardiac function in patients with compensated chronic heart failure (CHF) with and without periodic breathing (PB) or Cheyne-Stokes respiration (CSR). PATIENTS: We studied 132 patients (female, 13%; mean age, 53+/-8 years; body mass index, 25.9+/-3.5 kg/m2; left ventricular ejection fraction <40%; 23% in New York Heart Association class I, 43% in class II, and 34% in class III-IV). METHODS: Measurement of pulmonary function and blood gases, hemodynamic evaluation, analysis of breathing profile, echocardiography, recording of ECG, beat-to-beat arterial oxygen saturation, and respiration during spontaneous breathing. RESULTS: Fifty-eight percent of patients showed PB or CSR. Patients with PB or CSR have greater cardiac function impairment. Mean values of lung volumes and PaO2 were similar in the three groups of patients considered. In contrast, patients with PB or CSR had an increased minute ventilation and reduced PaCO2 values. Interestingly, patients with PB or CSR had lower values of arterial content of O2 and systemic oxygen transport (SOT) than patients with a normal breathing pattern (SOT, 394+/-9.8, 347+/-9.6, 438+/-11 mL of O2/min/m2, respectively; analysis of variance p<0.001). Weak correlations were found among lung volumes, blood gases, and cardiac function parameters: ie, vital capacity was correlated inversely with pulmonary capillary wedge pressure (PCWP) (-0.25; p<0.05); PaCO2 with PCWP (r=0.26; p<0.05), lung-to-ear circulation time (LECT) (r=-0.4; p<0.05), SOT (r=-0.33; p<0.0001), and cardiac index (CI) (r=0.27; p=0.003). Multiple regression analyses showed that arterial PCO2 was significantly correlated with SOT, LECT, and CI (r=0.51; r2=0.26; p<0.000001); the correlation became stronger considering only CSR patients (r=0.64; r2=0.4; p<0.001). CONCLUSIONS: Our study shows that patients with daytime breathing disorders have chronic hypocapnia. A reduced SOT may be one of the stimuli determining increased minute ventilation in these patients.

Chronic respiratory failure in a patient with type I Arnold-Chiari malformation (ACM1) and syringomyelia.

We present the case of a young adult with type I Arnold-Chiari malformation (AMC1) and syringomyelia who developed central sleep apnoea and chronic respiratory failure, successfully treated with nocturnal noninvasive positive pressure ventilation ventilation (NIPPV). An extensive syringomyelic cavity (from bulbar to L4 segment) with severe impairment of the IX cranial nerve was documented and remains, although reduced, after the neurosurgical treatment. At baseline evaluation, the patient showed a moderate restrictive ventilatory defect, severe hypercapnic respiratory failure, abnormal control of breathing characterized by the absence of response to hypoxia and hypercapnia, and severe nocturnal central apnoeas. Nocturnal NIPPV was then started in the A/C mode with an improvement in blood gas values. Further evaluations were performed 10 and 18 months later. A progressive significant improvement of lung volumes, both in sitting and supine position, associated with a slight improvement of blood-gas values were observed. Nonetheless, the breathing pattern abnormalities persisted. Polysomnographic evaluation during mechanical ventilation showed a normalization of breathing pattern with arterial oxygen saturation (SaO2) > 90% throughout the night.

Obstructive sleep apnoea syndrome: is the "half-night polysomnography" an adequate method for evaluating sleep profile and respiratory events?

Recently, to reduce the costs of polysomnography, split-night studies have been introduced into routine practice: the first part of the night is used to make the diagnosis of obstructive sleep apnoea syndrome (OSAS) and the second part to achieve an appropriate level of continuous positive airway pressure. Since this split-night protocol has not yet been validated by the comparison of polysomnographic pictures obtained in the first and second parts of the night, the aim of this study was to evaluate sleep profile and respiratory disturbances in the first part (PSG1) and second (PSG2) portion of a standard full-night polysomnographic examination (PSGtot) in a group of OSAS patients. Twenty nine consecutive OSAS patients, aged 54+/-10 yrs; body mass index (BMI) 40+/-6 kg x m(-2) (mean+/-SD values), were studied by separate analyses of PSG1, PSG2 and PSGtot. PSG1 was found to have a low sensitivity value (66%). A significant difference was found between apnoea-hypopnoea indices (AHI) recorded in PSG1, PSG2 and PSGtot (mean+/-SD, AHI1 33+/-27, AHI2 45+/-28, AHItot 40+/-25 events x h(-1), respectively; p<0.01). A strong correlation was observed between AHItot and AHI1 (r=0.89) and between AHItot and AHI2 (r=0.92), but a weaker correlation between AHI1 and AHI2 (r=0.66). These correlations became weaker when patients were subdivided into two different classes on the basis of disease severity. PSG1 was representative of PSGtot and similar to PSG2 only in those patients with rapid eye movement (REM) phase sleep in the first part of the night. We conclude that split-night protocols are not appropriate for evaluating sleep-disordered breathing in obstructive sleep apnoea syndrome patients when rapid eye movement phase sleep does not occur in the first part of the night.

Human and financial costs of noninvasive mechanical ventilation in patients affected by COPD and acute respiratory failure.

STUDY OBJECTIVES: It has been suggested that noninvasive mechanical ventilation (NIMV) may be a time-consuming procedure for medical and paramedical personnel. We carried out a prospective trial in 10 consecutive COPD patients aimed at assessing the human and economic resources needed to ventilate patients by NIMV and we compared these with those needed by a group of six patients receiving invasive mechanical ventilation (InMV). DESIGN: The daily cost and the minutes spent by medical doctors (MDs), respiratory therapists (RTs), and nurses (Ns) were recorded during the first 48 h of ventilation in 10 patients during NIMV (group A) and in six who received InMV (group B) after an initial unsuccessful attempt with NIMV. In two subgroups of patients (five for group A and four for group B), the analysis was also performed, except for RTs, for the total length of mechanical ventilation. SETTING: A respiratory ICU. PATIENTS: At hospital admission, the two groups of COPD patients did not differ for blood gas values (PaCO2 = 88.2+/-9.8 mm Hg for group A vs 90.5+/-12.8 mm Hg for group B, and pH = 7.21+0.08 vs 7.20+0.08, respectively) or for clinical and neurologic status, but patients of group B had not tolerated NIMV. MEASUREMENTS AND RESULTS: The total time spent at the bedside in the first 6 h did not differ between group A and B (group A = 72.3 min [MD], 87.2 min [RT], and 178.8 min [N] vs 98.8 min [MD], 12.5 min [RT], and 197.6 min [N] for group B). In the following 42 h, a plateau was reached so that there was a significant reduction for both groups in the time of assistance given by Ns (p<0.001) but not by MDs or RTs. The total costs were also not different between the two groups ($806+/-73 [US dollars per day] vs $864+/-44 for group A and B, respectively). In the subgroups monitored for the entire period of ventilation, a significant reduction in the time of assistance, for both MDs and Ns, was observed after approximately the first half. CONCLUSIONS: We conclude that in the first 48 h of ventilation, daily NIMV is neither more expensive nor time-consuming and staff demanding than InMV. After the first few days of ventilation, NIMV was significantly less time-consuming than InMV, for MDs and Ns, so that medical and paramedical time expenditure seems not to be a major problem during NIMV.

Lung transplantation: the experience of the Thoracic Organ Transplantation Centre of Pavia.

Between January 1991 and September 1995 at the Thoracic Organ Transplantation Centre of Pavia, 193 patients entered the waiting list for heart-lung or lung transplantation. Indications for heart-lung transplantation (HLT) were mainly primary or secondary pulmonary vascular diseases. Parenchymal lung diseases were the most frequent reasons for single- (SLT) or double-lung (DLT) transplantation. During the same period, 21 patients underwent HLT, 16 SLT and 14 DLT. Early deaths (within 30 days of surgery) occurred in 2 (10%) HLT, in 3 (19%) SLT, and in 3 (21%) DLT. Nineteen (90%) patients with HLT, 11 (69%) with SLT, and 10 (71%) with DLT survived up to 3 months; and 11 (52%) patients with HLT, 8 (50%) with SLT, and 5 (36%) with DLT survived up to 12 months. At the time of writing, the following patients are still alive: 10 (48%) with HLT, after a mean +/- SEM follow-up of 37.2 +/- 6 (range 28-46) months, 12 (75%) with SLT, after a mean follow-up of 16 +/- 11 (range 1-35) months, and finally 7 (50%) with DLT, after mean follow-up of 14 +/- 9 (range 1-23) months.

Physiological effects of flow and pressure triggering during non-invasive mechanical ventilation in patients with chronic obstructive pulmonary disease.

BACKGROUND: The effect of the type of trigger system on inspiratory effort has been studied in intubated patients, but no data are available in non-invasive mechanical ventilation where the "trigger variable" may be even more important since assisted modes of ventilation are often employed from the beginning of mechanical ventilation. METHODS: The effect of flow triggering (1 and 5 1/min) and pressure triggering (-1 cm H2O) on inspiratory effort during pressure support ventilation (PSV) and assisted controlled mode (A/C) delivered non-invasively with a full face mask were compared in patients with chronic obstructive pulmonary disease (COPD) recovering from an acute exacerbation. The patients were studied during randomised 15 minute runs at zero positive end expiratory pressure (ZEEP). The oesophageal pressure time product (PTPoes), dynamic intrinsic PEEP (PEEPi,dyn), fall in maximal airway pressure (delta Paw) during inspiration, and ventilatory variables were measured. RESULTS: Minute ventilation, respiratory pattern, dynamic lung compliance and resistances, and changes in end expiratory lung volume (delta EELV) were the same with the two triggering systems. The total PTPoes and its pre-triggering phase (PTP due to PEEPi and PTP due to valve opening) were significantly higher during both PSV and A/C with pressure triggering than with flow triggering at both levels of sensitivity. delta Paw was larger during pressure triggering, and PEEPi,dyn was significantly reduced during flow triggering in the A/C mode only. CONCLUSIONS: In patients with COPD flow triggering reduces the inspiratory effort during both PSV and A/C modes compared with pressure triggering. These findings are likely to be due to a reduction in PEEPi,dyn and in the time of valve opening with a flow trigger.

Time course of exercise capacity, skeletal and respiratory muscle performance after heart-lung transplantation.

Recipients of heart-lung transplantation (HLT) show reduced exercise capacity due to several pre- and postsurgical factors. The aim of this study was to evaluate the time course of exercise capacity, and skeletal and respiratory muscle performance in 11 patients (5 females and 6 males; age (mean +/- SD) 38 +/- 13 yrs) undergoing HLT. All of the patients were admitted to our institution for a rehabilitation programme after surgery, and were followed-up for 18 months. On admission, at discharge after an in-patient rehabilitation programme, and every 6 months, patients underwent evaluation of: lung function values; incremental treadmill exercise, 6 min walking distance (6-MWD); maximal inspiratory and expiratory pressures (MIP and MEP, respectively); and peak torque of isokinetic contraction of leg flexor and extensor muscles (IFX and IEX, respectively). On admission, patients had: reduced lung volumes as assessed by vital capacity (VC) (60 +/- 15% of predicted); reduced exercise capacity as assessed by peak oxygen consumption (V'O2,peak) (40 +/- 12% pred); reduced skeletal and respiratory muscle performance as assessed by IEX, IFX (48 +/- 16 and 28 +/- 12 Newton-metres (N x m), respectively) and by MIP and MEP (54 +/- 21 and 58 +/- 19 cmH2O, respectively). Ten patients completed the rehabilitation programme. At discharge, no significant change in dynamic and static lung volumes was observed. However, nonsignificant increases in MIP, MEP, IEX, IFX, 6-MWD and V'O2,peak were recorded. After 6 and 12 months, indices of skeletal and respiratory muscle function and V'O2, peak improved further, but still remained lower than normal values. We conclude that in patients with heart-lung transplantation, skeletal and respiratory muscle function and exercise performance are reduced after surgery, that they may improve with time but are still less than normal after 18 months.