Self-setup of home respiratory polygraphy for the diagnosis of sleep apnea syndrome: cost-efficiency study.

PURPOSE: To evaluate the differences in reliability and costs of home respiratory polygraphy (HRP) when installed by the patient and by a nurse, in order to determine the factors affecting and to consider the possible generalization of self-setup procedure. Several HRP devices have been validated for obstructive sleep apnea (OSA) diagnosis but convenience of a nurse intervention in HRP installation has been scarcely studied. METHODS: This is a prospective and interventional study. About 301 participants were assigned to 2 groups: self-setup and nurse intervention. Sleep study, questionnaires, and diagnostic procedures were performed following the clinical practice in 2016. Signals were considered lost above 3 min, and success of the test was established according to guidelines. Costs were calculated according to a previous multicenter study. RESULTS: Both groups (self-setup and nurse intervention) resulted homogeneous in age, gender, BMI, and final diagnosis of OSA. Signal losses during the test were similar in both groups. Slightly higher percentage of unsuccessful tests were obtained in the self-setup procedure (5.3 vs 2.0%, p = 0.121). The costs were similar (107 vs 105 €) in the self-setup group as compared to the nurse setup group. CONCLUSIONS: The setup of HRP by either the patient or nurse had similar costs and data acquisition. Both installation procedures of HRP were similar regarding test reliability and costs. Main findings are that self-installation by the patient could be similarly reliable and economic as installation by a nurse, as far as consensus guidelines are followed. This study demonstrates that self-setup of HRP is a potentially viable option for the diagnosis of OSA.

Flow and airway pressure analysis for detecting ineffective effort during mechanical ventilation in neuromuscular patients.

Ineffective efforts (IEs) are among the most common types of patient-ventilator asynchrony. The objective of this study is to validate IE detection during expiration using pressure and flow signals, with respiratory effort detection by esophageal pressure (Pes) measurement as the reference, in patients with neuromuscular diseases (NMDs). We included 10 patients diagnosed with chronic respiratory failure related to NMD. Twenty-eight 5-minute recordings of daytime ventilation were studied for IE detection. Standard formulas were used to calculate sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of IE detection using pressure and flow signals compared to Pes measurement. Mean sensitivity and specificity of flow and pressure signal-based IE detection versus Pes measurement were 97.5% ± 5.3% and 91.4% ± 13.7%, respectively. NPV was 98.1% ± 8.2% and PPV was 67.6% ± 33.8%. Spearman's rank correlation coefficient indicated a moderately significant correlation between frequencies of IEs and controlled cycles ( ρ = 0.50 and p = 0.01). Among respiratory cycles, 311 (11.2%) were false-positive IEs overall. Separating false-positive IEs according to their mechanisms, we observed premature cycling in 1.2% of cycles, delayed ventilator triggering in 0.1%, cardiac contraction in 9.2%, and upper airway instability during expiration in 0.3%. Using flow and pressure signals to detect IEs is a simple and rapid method that produces adequate data to support clinical decisions.

A novel presentation of diaphragmatic flutter in a patient with obstructive sleep apnea and recurrent cerebellar hemangioblastoma.

We report a unique case of diaphragmatic flutter in a patient with obstructive sleep apnea who had no respiratory symptoms related to flutter and a history of recurrent cerebellar hemangioblastoma. The flutter was detected during a routine follow-up monitoring through the built-in software of the positive airway pressure device; the flow and pressure curves showed abnormal and curious oscillations. The ultrasound confirmed the diagnosis and ruled out other causes of abnormal diaphragmatic movements. This case report contributes to the scientific literature by presenting a novel case of diaphragmatic flutter associated with recurrent cerebellar hemangioblastoma. It also emphasizes the need for more research on the pathophysiology and treatment of this rare condition. CITATION: Ciorba C, Espinoza Perez JA, Alfonso Imizcoz M, Errasti Viader J, Cebollero Rivas P, De Vito EL. A novel presentation of diaphragmatic flutter in a patient with obstructive sleep apnea and recurrent cerebellar hemangioblastoma. J Clin Sleep Med. 2024;20(2):313-317.

Characterization of the paracrine effects of human skeletal myoblasts transplanted in infarcted myocardium.

BACKGROUND: The discrepancy between the functional improvements yielded experimentally by skeletal myoblasts (SM) transplanted in infarcted myocardium and the paucity of their long-term engraftment has raised the hypothesis of cell-mediated paracrine mechanisms. METHODS AND RESULTS: We analyzed gene expression and growth factors released by undifferentiated human SM (CD56(+)), myotubes (SM cultured until confluence) and fibroblasts-like cells (CD56(-)). Gene expression revealed up-regulation of pro-angiogenic (PGF), anti-apoptotics (BAG-1, BCL-2), heart development (TNNT2, TNNC1) and extracellular matrix remodelling (MMP-2, MMP-7) genes in SM. In line with the gene expression profile, the analysis of culture supernatants of SM by ELISA identified the release of growth factors involved in angiogenesis (VEGF, PIGF, angiogenin, angiopoietin, HGF and PDGF-BB) as well as proteases involved in matrix remodelling (MMP2, MMP9 and MMP10) and their inhibitors (TIMPs). Culture of smooth muscle cells (SMC), cardiomyocytes (HL-1) and human umbilical vein endothelial cells (HUVECs) with SM-released conditioned media demonstrated an increased proliferation of HUVEC, SMC and cardiomyocytes (p<0.05) and a decrease in apoptosis of cardiomyocytes (p<0.05). Analysis of nude rats transplanted with human SM demonstrated expression of human-specific MMP-2, TNNI3, CNN3, PGF, TNNT2, PAX7, TGF-beta, and IGF-1 1 month after transplant. CONCLUSIONS: Our data support the paracrine hypothesis whereby myoblast-secreted factors may contribute to the beneficial effects of myogenic cell transplantation in infarcted myocardium.