American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Jan 1996
Comparative StudyNocturnal saturation improves by target-flow inspiratory muscle training in patients with COPD.
Nocturnal desaturations during rapid eye movement (REM) sleep, caused by nonobstructive hypoventilation, occur frequently in patients with chronic obstructive pulmonary disease (COPD). This is partly caused by decreased activity of the intercostal and accessory muscles due to a lower motor command. The diaphragm has to compensate for the diminished activity of these muscles during REM sleep. ⋯ PImax, Pdi, SIPmax, and the endurance time as well as the nocturnal saturation improved significantly in the 60% training group (by 3.0 +/- 1.5 kPa, 3.4 +/- 1.9 kPa, 1.5 +/- 1.4 kPa, 189 +/- 149 s, and 1.9 +/- 2.2%, respectively), whereas no changes occurred in the sham training group. Also, significant correlations were observed between the changes in Pdi, SIPmax, and endurance time on the one hand and the change in nocturnal saturation on the other. We conclude that TF-IMT improves the nocturnal saturation in patients with severe COPD by increasing respiratory muscle strength and endurance.
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Am. J. Respir. Crit. Care Med. · Jan 1996
Comparative StudyFluorodeoxyglucose-positron emission tomography in the detection and staging of lung cancer.
Glycolysis is increased in tumor tissues. [18F]fluoro-2-deoxy-D-glucose (FDG) is a glucose analogue radiopharmaceutical used in positron emission tomography (PET) to trace glucose metabolism. We investigated the sensitivity and specificity of FDG-PET imaging in the diagnosis and staging of lung cancer. One hundred and seven patients who had abnormal chest roentgenograms underwent whole-body PET imaging using FDG. ⋯ Seven of these patients had lymphadenopathy on computed tomography. FDG-PET imaging is 100% accurate in predicting mediastinal involvement in patients with lung cancer. It is 100% sensitive and 52% specific in predicting the malignant nature of a chest radiographic abnormality.
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Am. J. Respir. Crit. Care Med. · Dec 1995
Comparative StudyMediastinal staging of non-small-cell lung cancer with positron emission tomography.
To determine the usefulness of positron emission tomography with fluoro-2-deoxyglucose (PET-FDG) in assessing mediastinal disease in patients with non-small-cell lung cancer (NSCLC) and to compare its yield to that of computed tomography (CT), we performed a prospective consecutive sample investigation in a university hospital and its related clinics. In 30 patients with NSCLC with clinical stage I (T1-2, NO, MO) disease, we compared the results of chest CT and PET-FDG with the findings at surgical exploration of the mediastinum. Seven (77%) of nine patients with surgically proven mediastinal metastasis were identified by the PET-FDG results, with four false-positives in 21 patients with negative lymph node dissections (p = 0.004). ⋯ The diagnostic accuracy of the combined imaging modalities was 90%. We concluded that mediastinal uptake of FDG correlates with the extent of mediastinal involvement of NSCLC and may contribute to preoperative staging. PET-FDG imaging complements chest CT in the noninvasive evaluation of NSCLC, and strategies for its use merit further investigation.
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Am. J. Respir. Crit. Care Med. · Dec 1995
Identification of patients with acute lung injury. Predictors of mortality.
A recent North-American-European Consensus Conference proposed new, uniform criteria for the definition of acute lung injury, in part to facilitate earlier identification of patients for clinical trials. However, these criteria have not been evaluated prospectively. We designed a prospective cohort study of 123 consecutive patients with acute lung injury prospectively identified on admission to the adult intensive care units of a tertiary care university hospital. ⋯ Overall hospital mortality was 58%. Sepsis was the most common clinical disorder (50/123 or 41%) associated with the development of acute lung injury. Using the new definition for acute lung injury, 66 of the 123 patients were enrolled with a PaO2/FIO2 ratio between 150 and 299; 57 of the 123 patients had a PaO2/FIO2 < 150 at the time of entry into the study.(ABSTRACT TRUNCATED AT 250 WORDS)
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Am. J. Respir. Crit. Care Med. · Dec 1995
Randomized Controlled Trial Clinical TrialBeneficial effects of the "open lung approach" with low distending pressures in acute respiratory distress syndrome. A prospective randomized study on mechanical ventilation.
Alveolar overdistention and cyclic reopening of collapsed alveoli have been implicated in the lung damage found in animals submitted to artificial ventilation. To test whether these phenomena are impairing the recovery of patients with acute respiratory distress syndrome (ARDS) submitted to conventional mechanical ventilation (MV), we evaluated the impact of a new ventilatory strategy directed at minimizing "cyclic parenchymal stretch." After receiving pre-established levels of hemodynamic, infectious, and general care, 28 patients with early ARDS were randomly assigned to receive either MV based on a new approach (NA, consisting of maintenance of end-expiratory pressures above the lower inflection point of the P x V curve, VT < 6 ml/kg, peak pressures < 40 cm H2O, permissive hypercapnia, and stepwise utilization of pressure-limited modes) or a conventional approach (C = conventional volume-cycled ventilation, VT = 12 ml/kg, minimum PEEP guided by FIO2 and hemodynamics and normal PaCO2 levels). ⋯ After correcting for baseline imbalances in APACHE II, we observed a higher weaning rate in NA (p = 0.014) but not a significantly improved survival (overall mortality: 5/15 in NA versus 7/13 in C, p = 0.45). We concluded that the NA ventilatory strategy can markedly improve the lung function in patients with ARDS, increasing the chances of early weaning and lung recovery during mechanical ventilation.