J. Moita

Síndroma do pulmão encolhido: Relato de um caso clínico e revisão da literatura

Respiratory complications of systemic lupus erythematosus may involve every element of the respiratory system and are relatively common as the initial manifestation of this disease occurring in 60 -80% of patients during the course of the disease. The authors report a case of a lupic patient with a respiratory manifestation rarely recognized which diagnostic approach and treatment still represents a clinical challenge.

Titration with automatic continuous positive airway pressure in obstructive sleep apnea

BACKGROUND AND OBJECTIVE Autotitrating positive airway pressure (APAP) is an accepted titration method to determine the optimal positive airway pressure (PAP), for the treatment of obstructive sleep apnea (OSA). The required duration of APAP monitoring to determine a fixed continuous positive airway pressure level still remains to be established. We aimed to evaluate the variation in PAP level, delivered by APAP devices, at different periods of treatment, to determine the APAP treatment duration required to reach an effective and stable PAP level. METHODS A cross-sectional study of 62 patients newly diagnosed with OSA were evaluated after 3 months of APAP therapy. APAP data corresponding to the first day (D1), first week (W1), seventh week (W7) and twelfth week (W12) under APAP therapy was collected. For the analysis of the pressure behaviour, the difference of P95th pressure level between W12 and W7 (P W12-W7), W12 and W1 (P W12-W1) and W12 and D1 (P W12-D1) was calculated. RESULTS There was a high correlation in P95th pressure level between D1 and W12 (r=0.771; p>0.0001), W1 and W12 (r=0.817; p>0.0001), and W7 and W12 (r=0.926; p>0.0001). This correlation progressively increased with APAP use. A significance difference was found in concordance between P W12-W7 and P W12-D1 (p=0.046) within the pressure range ±2cmH2O. However there was no significant difference in concordance between P W12-W7 and P W12-W1. CONCLUSIONS One week of APAP therapy seems sufficient to determine an effective and stable PAP level, within the pressure range ±2cmH2O.

Reply to the letter to the editor "Sleep disorders breathing in chronic heart failure. Is adaptive servoventilation really the answer?".

We thank you very much for the interesting questions about our article. In the group of patients with CSA/CSR (40.6% of the total patients) the diagnosis was made in the beginning, with a polissonography. In the group with CompSAS, the diagnosis was made in patients who presented central sleep apnea after starting treatment with autoCPAP/CPAP for obstructive sleep apnea. These patients maintained a high AHI despite treatment (more than 2--3 months after the beginning of the treatment) so they were submitted to a split-night study about 4 months after the initial sleep study. All the patients were submitted to a split night study and in all of the patients the technician always try first the treatment with PAP (CPAP/AutoCPAP/BIPAP) but because it did not resolved the central apnea, the technician switched to servoventilation, with excellent results. Only one patient was treated with BIPAP (S/T mode). The first pressures were 18/14 but the patient suddenly died and we had no time to optimize the best pressures for him. As the study is retrospective, not all the patients had previously realized echocardiogram before PAP therapy so the comparison between the two ventilatory modes concerning cardiac function cannot be made with confidence and we have declared this fact as a limitation of the study.

Controversies in the Cardiopulmonary Exercise Test use in evaluation of impairment and disability in Portugal

Pulmonologists are involved in the assessment of functional impairment in patients with occupational respiratory diseases. 1-3 These patients often complain that dyspnea on exertion interferes with their ability to do their job and they may be legally compensated according to the functional defi cit reported. 4,5 Cardiopulmonary exercise testing (CPET) is a valuable clinical test for assessment of exercise intolerance and is taken into account when providing relevant information to assess functional impairment and disability. 6-15 Several researchers have demonstrated the utility of CPET in determining the functional deficit. 16-22 Of all parameters determined, maximal Oxygen consumption (VO2 max) is the one that reveals exercise limitation and is used in most guidelines for quantifying functional impairment. 7-9 A normal VO2 max implies that respiratory function is preserved, showing no signifi cant functional defi cit. A decreased VO2 max may have several causes and the other parameters provide information to determine the factors that contribute to exercise intolerance (psychogenic, deconditioning, cardiovascular limitation, ventilatory limitation or limitation by gas exchange abnormalities). 16-19,23 The maximal oxygen consumption in office work is 5-7 mL/kg/min, in moderate physical work about 15 mL/kg/min and in

Qualidade de Sono e Parâmetros de Dessaturação Nocturna em Doentes com Doença Pulmonar Obstrutiva Crónica e Hipoxémia entre 55-70mmHg

Nocturnal desaturation is well recnognized in patients with chronic respiratory failure (CRF). Alveolar hypoventilation, particulary in REM sleep, is frequently assumed as the main physiopathological mechanism. This ocurrence is important in patients with mild basal hypoxemia (PaO2 55-70 mmHg) because of the particular position of the PaO2 in the oxyhemoglobin desaturation curve. However, disturbances of the quality of sleep that alter the normal structure of sleep in patients with chronic obstructive pulmonary disease (COPD) has been described in the literature. The objective of this study is to evaluate how the quality of sleep could afect the parameters of nocturnal desaturation and the definition of a patient as a desaturator. Twenty patients (15 men; 5 women; 68.2 ± 6.1 yrs) with stabilized CRF secondary to COPD (FEV1 = 1.024 ± 0.431 L; 47 ± 16.5% predicted) were submited to a polysomnographic study in two consecutive nights in ambient air, free of sedative medication and under usual broncodilator medication. In the first night of sleep the general pattern was insomnia and fragmented sleep (increase in sleep latency time, number of arousals and a decrease in the efficiency of sleep) with a consequent reduction in the time spent in 3-4 and REM sleep. In the second night of study a significant reduction of sleep latency time (72 ± 65.5 vs. 28 ± 31.4 mn; p = 0.008) and an increase in efficiency of sleep (52 ± 26.5 vs. 76 ± 13.4%; p < 0.0001) was seen, without any significant variation in the number of aroulsals and of the time in slow wave sleep but with a significant increase in REM sleep (6 ± 4.8 vs. 11 ± 6.5 %; p < 0.01). No significant differences were noted in the nocturnal desaturation parameters over the two nights although there was a large individual variability. Correlation between individual variation in sleep parameters and variation in desaturation parameters was significant for the variation in minimal saturation with variation in total sleep time (r = 0.559) and for the variation in time spent with SaO2 < 80 % with the time spent in REM sleep (r = 0.471). Using two definitions of desaturator patient – 1) more than 5 minutes with a SaO2 < 90% with at least one episode with minimal SaO2 < 85%; 2) more than 30% of the recorded time with SaO2 < 90% - it was concluded that for the first criteria 11/20 patients were desaturators on the second night vs 7/20 on first night (p = 0.002) and for the second criteria 9/20 vs. 7/20 for the second and first night respectively (p = 0.012). It was concluded that patients with COPD and mild hypoxemia show a bad quality of sleep with a “first night effect”. No significant variation in nocturnal desaturation parameters was seen in a second night of sleep but the intensity of the desaturation and the classification of a patient as desaturator can be affected. REV PORT PNEUMOL 2001; VII (2):

The effect of left ventricular dysfunction on nocturnal desaturation in patients with chronic emphysematous bronchitis and PaO2 55-70 mmHg.

The possibility of nocturnal oxygen desaturation (NOD) in patients with chronic bronchitis and emphysema (CBE) even with basal hypoxemia greater that 55 mmHg is well recognised. Nocturnal hypoventilation is admitted as the main cause for this NOD. In this study we evaluate how the presence of left ventricular dysfunction (LVD) could aggravate NOD. Thirty-six patients with CBE and basal stabilised PaO2 55-70 mmHg underwent right heart catheterisation and polysomnographic study. NOD was defined as more than 30% of total sleep time with SaO2 less than 90%; LVD was defined as capillary pressure greater than 15 mmHg. Six patients were excluded from analysis because of sleep apnoea syndrome. In the remaining 30 patients (20 men, 10 women; mean age = 65.88.6 years; mean FEV1 = 0.970.31 litres; 43.316.6% predicted; mean basal PaO2 = 61.83.6 mmHg) 8 had LVD and 18 and NOD. Patients with NOD had a greater diurnal level of hypoventilation (basal PaCO2 = 44.63.8 vs. 414.1 mmHg; p = 0.025). Patients with LVD, despite identical diurnal pulmonary function, showed a significantly p < 0.05) greater degree of NOD (mean nocturnal SaO2 = 84.56.4 vs 89.52.5; minimal nocturnal SaO2= 68.517.3 vs. 79.47.8; Time spent with SaO2 < 90% = 78.833.7 vs. 43.138.7). We conclude that the presence of LVD in patients with CBE and PaO2 55-70 mmHg aggravates the intensity and the time spent with NOD, probably because of aggravation of hypoventilation or ventilation/perfusion mismatching.