Christina Triantafillidou

Sleep oxygen desaturation predicts survival in idiopathic pulmonary fibrosis.

BACKGROUND Recent studies suggest poor sleep quality in patients with idiopathic pulmonary fibrosis (IPF). However, so far, the impact of IPF-related sleep breathing disorders (SBDs) on survival has not been extensively studied. METHODS In a cohort of 31 (24 males) treatment-naïve, newly diagnosed consecutive IPF patients, we prospectively investigated the relationship of SBD parameters such as apnea-hypopnea index (AHI), maximal difference in oxygen saturation between wakefulness and sleep (maxdiff SpO2), and lowest sleep oxygen saturation (lowest SpO2) with clinical (survival, dyspnea, daytime sleepiness), pulmonary function, submaximal (6-min walk test [6MWT]) and maximal exercise variables (cardiopulmonary exercise test [CPET]), and right ventricular systolic pressure (RVSP). RESULTS Sleep oxygen desaturation exceeded significantly that of maximal exercise (p < 0.001). Maxdiff SpO2 was inversely related to survival, DLCO%, and SpO2 after 6MWT, and directly with dyspnea, AHI, and RVSP. The lowest SpO2 was directly related to survival and to functional (TLC%, DLCO%) as well as submaximal and maximal exercise variables (6MWT distance, SpO2 after 6MWT, peak oxygen consumption/kg, SpO2 at peak exercise), while an inverse association with dyspnea score, AHI, and RVSP was observed. CONCLUSIONS Our findings provide evidence that intermittent sleep oxygen desaturation significantly exceeds that of maximal exercise and is associated with survival in IPF patients. Furthermore, they imply the existence of a link between lung damage and apnea events resulting to the induction and severity of intermittent sleep oxygen desaturation that aggravate pulmonary arterial hypertension and influence IPF survival.

MRC chronic Dyspnea Scale: Relationships with cardiopulmonary exercise testing and 6-minute walk test in idiopathic pulmonary fibrosis patients: a prospective study.

BackgroundExertional dyspnea is the most prominent and disabling feature in idiopathic pulmonary fibrosis (IPF). The Medical Research Chronic (MRC) chronic dyspnea score as well as physiological measurements obtained during cardiopulmonary exercise testing (CPET) and the 6-minute walk test (6MWT) are shown to provide information on the severity and survival of disease.MethodsWe prospectively recruited IPF patients and examined the relationship between the MRC score and either CPET or 6MWT parameters known to reflect physiologic derangements limiting exercise capacity in IPF patientsResultsTwenty-five patients with IPF were included in the study. Significant correlations were found between the MRC score and the distance (r = -.781, p < 0.001), the SPO2 at the initiation and the end (r = -.542, p = 0.005 and r = -.713, p < 0.001 respectively) and the desaturation index (r = .634, p = 0.001) for the 6MWT; the MRC score and VO2 peak/kg (r = -.731, p < 0.001), SPO2 at peak exercise (r = -. 682, p < 0.001), VE/VCO2 slope (r = .731, p < 0.001), VE/VCO2 at AT (r = .630, p = 0.002) and the Borg scale at peak exercise (r = .50, p = 0.01) for the CPET. In multiple logistic regression analysis, the only variable independently related to the MRC is the distance walked at the 6MWT.ConclusionIn this population of IPF patients a good correlation was found between the MRC chronic dyspnoea score and physiological parameters obtained during maximal and submaximal exercise testing known to reflect ventilatory impairment and exercise limitation as well as disease severity and survival. This finding is described for the first time in the literature in this group of patients as far as we know and could explain why a simple chronic dyspnea score provides reliable prognostic information on IPF.

Combined pulmonary fibrosis and emphysema

The advent of computed tomography permitted recognition of the coexistence of pulmonary fibrosis and emphysema (CPFE). Emphysema is usually encountered in the upper lobes preceding fibrosis of the lower lobes, and patients are smokers, predominantly male, with distinct physiologic profile characterized by preserved lung volumes and markedly reduced diffusion capacity. Actually, the term CPFE is reserved for the coexistence of any type and grade of radiological pulmonary emphysema and the idiopathic usual interstitial pneumonia computed tomography pattern as well as any pathologically confirmed case. CPFE is complicated by pulmonary hypertension, lung cancer and acute lung injury and may present different outcome than that of its components.

Static and dynamic mechanics of the murine lung after intratracheal bleomycin

BackgroundDespite its widespread use in pulmonary fibrosis research, the bleomycin mouse model has not been thoroughly validated from a pulmonary functional standpoint using new technologies. Purpose of this study was to systematically assess the functional alterations induced in murine lungs by fibrogenic agent bleomycin and to compare the forced oscillation technique with quasi-static pressure-volume curves in mice following bleomycin exposure.MethodsSingle intratracheal injections of saline (50 μL) or bleomycin (2 mg/Kg in 50 μL saline) were administered to C57BL/6 (n = 40) and Balb/c (n = 32) mice. Injury/fibrosis score, tissue volume density (TVD), collagen content, airway resistance (RN ), tissue damping (G) and elastance coefficient (H), hysteresivity (η), and area of pressure-volume curve (PV-A) were determined after 7 and 21 days (inflammation and fibrosis stage, respectively). Statistical hypothesis testing was performed using one-way ANOVA with LSD post hoc tests.ResultsBoth C57BL/6 and Balb/c mice developed weight loss and lung inflammation after bleomycin. However, only C57BL/6 mice displayed cachexia and fibrosis, evidenced by increased fibrosis score, TVD, and collagen. At day 7, PV-A increased significantly and G and H non-significantly in bleomycin-exposed C57BL/6 mice compared to saline controls and further increase in all parameters was documented at day 21. G and H, but not PV-A, correlated well with the presence of fibrosis based on histology, TVD and collagen. In Balb/c mice, no change in collagen content, histology score, TVD, H and G was noted following bleomycin exposure, yet PV-A increased significantly compared to saline controls.ConclusionsLung dysfunction in the bleomycin model is more pronounced during the fibrosis stage rather than the inflammation stage. Forced oscillation mechanics are accurate indicators of experimental bleomycin-induced lung fibrosis. Quasi-static PV-curves may be more sensitive than forced oscillations at detecting inflammation and fibrosis.

Acute severe asthma: new approaches to assessment and treatment.

The precise definition of a severe asthmatic exacerbation is an issue that presents difficulties. The term ‘status asthmaticus’ relates severity to outcome and has been used to define a severe asthmatic exacerbation that does not respond to and/or perilously delays the repetitive or continuous administration of short-acting inhaled β2-adrenergic receptor agonists (SABA) in the emergency setting. However, a number of limitations exist concerning the quantification of unresponsiveness. Therefore, the term ‘acute severe asthma’ is widely used, relating severity mostly to a combination of the presenting signs and symptoms and the severity of the cardiorespiratory abnormalities observed, although it is well known that presentation does not foretell outcome.In an acute severe asthma episode, close observation plus aggressive administration of bronchodilators (SABAs plus ipratropium bromide via a nebulizer driven by oxygen) and oral or intravenous corticosteroids are necessary to arrest the progression to severe hypercapnic respiratory failure leading to a decrease in consciousness that requires intensive care unit (ICU) admission and, eventually, ventilatory support. Adjunctive therapies (intravenous magnesium sulfate and/or others) should be considered in order to avoid intubation. Management after admission to the hospital ward because of an incomplete response is similar.The decision to intubate is essentially based on clinical judgement. Although cardiac or respiratory arrest represents an absolute indication for intubation, the usual picture is that of a conscious patient struggling to breathe. Factors associated with the increased likelihood of intubation include exhaustion and fatigue despite maximal therapy, deteriorating mental status, refractory hypoxaemia, increasing hypercapnia, haemodynamic instability and impending coma or apnoea. To intubate, sedation is indicated in order to improve comfort, safety and patient-ventilator synchrony, while at the same time decrease oxygen consumption and carbon dioxide production. Benzodiazepines can be safely used for sedation of the asthmatic patient, but time to awakening after discontinuation is prolonged and difficult to predict. The most common alternative is propofol, which is attractive in patients with sudden-onset (near-fatal) asthma who may be eligible for extubation within a few hours, because it can be titrated rapidly to a deep sedation level and has rapid reversal after discontinuation; in addition, it possesses bronchodilatory properties. The addition of an opioid (fentanyl or remifentanil) administered by continuous infusion to benzodiazepines or propofol is often desirable in order to provide amnesia, sedation, analgesia and respiratory drive suppression.Acute severe asthma is characterized by severe pulmonary hyperinflation due to marked limitation of the expiratory flow. Therefore, the main objective of the initial ventilator management is 2-fold: to ensure adequate gas exchange and to prevent further hyperinflation and ventilator-associated lung injury. This may require hypoventilation of the patient and higher arterial carbon dioxide (PaCO2) levels and a more acidic pH. This does not apply to asthmatic patients intubated for cardiac or respiratory arrest. In this setting the post-anoxic brain oedema might demand more careful management of PaCO2 levels to prevent further elevation of intracranial pressure and subsequent complications. Monitoring lung mechanics is of paramount importance for the safe ventilation of patients with status asthmaticus.The first line of specific pharmacological therapy in ventilated asthmatic patients remains bronchodilation with a SABA, typically salbutamol (albuterol). Administration techniques include nebulizers or metered-dose inhalers with spacers. Systemic corticosteroids are critical components of therapy and should be administered to all ventilated patients, although the dose of systemic corticosteroids in mechanically ventilated asthmatic patients remains controversial. Anticholinergics, inhaled corticosteroids, leukotriene receptor antagonists and methylxanthines offer little benefit, and clinical data favouring their use are lacking.In conclusion, expertise, perseverance, judicious decisions and practice of evidence-based medicine are of paramount importance for successful outcomes for patients with acute severe asthma.

The Role of Cardiopulmonary Exercise Test in IPF Prognosis

Background. In IPF, defects in lung mechanics and gas exchange manifest with exercise limitation due to dyspnea, the most prominent and disabling symptom. Aim. To evaluate the role of exercise testing through the 6MWT (6-minute walk test) and CPET (cardiopulmonary exercise testing) in the survival of patients with IPF. Methods. This is a prospective, observational study evaluating in 25 patients the relationship between exercise variables through both the 6MWT and CPET and survival. Results. By the end of the observational period 17 patients were alive (33% mortality). Observation ranged from 9 to 64 months. VE/VCO2 slope (slope of relation between minute ventilation and CO2 production), VO2 peak/kg (peak oxygen consumption/kg), VE/VCO2 ratio at anaerobic threshold, 6MWT distance, desaturation, and DLCO% were significant predictors of survival while VE/VCO2 slope and VO2 peak/kg had the strongest correlation with outcome. The optimal model for mortality risk estimation was VO2 peak/kg + DLCO% combined. Furthermore, VE/VCO2 slope and VO2 peak/kg were correlated with distance and desaturation during the 6MWT. Conclusion. The integration of oxygen consumption and diffusing capacity proved to be a reliable predictor of survival because both variables reflect major underlying physiologic determinants of exercise limitation.

Pulmonary alveolar proteinosis: time to shift?

Pulmonary alveolar proteinosis (PAP) is categorized into hereditary, secondary and autoimmune PAP (aPAP) types. The common pathogenesis is the ability of the alveolar macrophages to catabolize phagocytized surfactant is affected. Hereditary PAP is caused by mutations involving the GM-CSF signaling, particularly in genes for the GM-CSF receptor and sometimes by GATA2 mutations. Secondary PAP occurs in hematologic malignancies, other hematologic disorders, miscellaneous malignancies, fume and dust inhalation, drugs, autoimmune disorders and immunodeficiencies. aPAP is related to the production of GM-CSF autoantibodies. PAP is characterized morphologically by the inappropriate and progressive ‘occupation’ of the alveolar spaces by an excessive amount of unprocessed surfactant, limiting gas exchange and gradually exhausting the respiratory reserve. Myeloid cells’ immunity deteriorates, increasing the risk of infections. Treatment of PAP is based on its etiology. In aPAP, recent therapeutic advances might shift the treatment option from the whole lung lavage procedure under general anesthesia to the inhalation of GM-CSF ‘as needed’.

Pirfenidone treatment in idiopathic pulmonary fibrosis: too much of a great expectation?

To the Editors: Idiopathic pulmonary fibrosis (IPF) is a dreadful, chronic and irreversibly progressive fibrosing disease lacking any effective treatment and leading to death in all affected patients [1, 2]. The scientific community is becoming aware that corticosteroids and immunosuppressors have failed to prove any efficacy concerning both mortality and the prevention of devastating complications, such as IPF acute exacerbations [1, 3]. Not only has this approach proven ineffective, but also harmful. Recently, the National Heart, Lung, and Blood Institute (Bethesda, MD, USA) aborted the continuation of treatment of combined prednisone, azathioprine and N -acetylcysteine (one arm of the three-arm multicentre PANTHER-IPF clinical trial) due to safety concerns [4]. The results of the interim analyses revealed that patients with IPF receiving the conventionally used triple-drug therapy consisting of prednisone, azathioprine and N -acetylcysteine had worse outcomes than those who received matched placebos. Thus, the need for an effective and safe treatment for IPF is still being pursued in several clinical trials. Pirfenidone (5-methyl-1-phenyl-2-[1H]-pyridone), a novel compound with anti-inflammatory, antifibrogenic and antioxidant properties, appears promising in IPF patients [1, 2 …

The many faces of sarcoidosis: asymptomatic muscle mass mimicking giant-cell tumor

Sarcoidosis is a chronic, multisystem granulomatous disease of unknown etiology. Muscle involvement is frequent, but often asymptomatic. There are three forms of muscular sarcoidosis: only the nodular type can be recognized by imaging. MRI and 18F-FDG PET–CT are the best methods to attempt the diagnosis of nodular muscular sarcoidosis; nevertheless, the lesion can mimic a malignant tumor. In this case, biopsy is the only tool to identify the disease.

Bronchiolitis: adopting a unifying definition and a comprehensive etiological classification

Bronchiolitis is an inflammatory and potentially fibrosing condition affecting mainly the intralobular conducting and transitional small airways. Secondary bronchiolitis participates in disease process of the airways and/or the surrounding lobular structures in the setting of several already defined clinical entities, mostly of known etiology, and occurs commonly. Primary or idiopathic bronchiolitis dominates and characterizes distinct clinical entities, all of unknown etiology, and occurs rarely. Secondary bronchiolitis regards infections, hypersensitivity disorders, the whole spectrum of smoking-related disorders, toxic fumes and gas inhalation, chronic aspiration, particle inhalation, drug-induced bronchiolar toxicities, sarcoidosis and neoplasms. Idiopathic or primary bronchiolitis defines clinicopathologic entities sufficiently different to be designated as separate disease entities and include cryptogenic constrictive bronchiolitis, diffuse panbronchiolitis, diffuse idiopathic pulmonary neuroendocrine cell hyperplasia, neuroendocrine hyperplasia in infants, bronchiolitis obliterans syndrome in lung and allogeneic hematopoietic cell transplantation, connective tissue disorders, inflammatory bowel disease and bronchiolitis obliterans organizing pneumonia. Most of the above are pathological descriptions used as clinical diagnosis. Acute bronchiolitis, though potentially life threatening, usually regresses. Any etiology chronic bronchiolitis contributes to morbidity and/or mortality if it persists and/or progresses to diffuse airway narrowing and distortion or complete obliteration. Bronchiolitis in specific settings leads to bronchiolectasis, resulting in bronchiectasis.