Diagnostic accuracy of daytime polysomnography: a reappraisal during the COVID-19 era.

Level I conventional polysomnography (PSG), the gold standard for diagnosing obstructive sleep apnea (OSA), requires an overnight stay. This study evaluated the role of daytime PSG as an alternative diagnostic tool. A prospective cohort study was undertaken with consecutive patients with suspected OSA at a tertiary care sleep center. The primary objective was to evaluate the sensitivity and diagnostic accuracy of daytime PSG for diagnosing OSA. The secondary objective was to find out the factors associated with a falsely negative daytime PSG result. All individuals were subjected to level I daytime PSG, done in the sleep lab in the presence of an experienced sleep technician during the daytime from 12 PM to 4 PM. Out of 162 patients, 105 underwent daytime PSG. OSA was diagnosed on daytime PSG in 86.7 out of the 19 remaining patients refused a repeat PSG study. Out of the 12 individuals who underwent the nighttime PSG for confirmatory diagnosis, 10 were diagnosed as OSA (false negatives), and 2 were confirmed as not-OSA (true negatives). The sensitivity, diagnostic accuracy, and negative predictive value of daytime PSG were 89.58%, 89.80%, and 16.67%, respectively. The false negatives had a higher prevalence of mild OSA. Daytime PSG is sensitive in diagnosing OSA and can be considered in individuals with severe symptoms at centers with a high patient load or when the individual wishes to avoid a nighttime study. A negative result in daytime PSG must be followed by conventional overnight PSG for confirmatory diagnosis.

Basic spirometry and advanced pulmonary function tests - NATCON 2022.

At the 77th National Conference on Tuberculosis and Chest Diseases, which took place on February 27, 2023, a pre-conference workshop on Basic Spirometry and Advanced Pulmonary Function Tests was held under the auspices of NATCON-2022. With the assistance of highly experienced faculty who are national and international level experts in their fields, the workshop covered all important aspects of basic spirometry and advanced Pulmonary Function Tests.

A study on the prevalence of RLS in OSA and the consequences of co-occurrence.

Background: Restless leg syndrome (RLS) is common among patients with obstructive sleep apnoea (OSA) but the prognostic importance of this is not studied. We have called OSA and RLS coexistence as ComOSAR. Materials and Methods: A prospective observational study was done on patients referred for polysomnography (PSG) with the aims to evaluate 1) the prevalence of RLS in OSA and comparing it with RLS in non-OSA, 2) the prevalence of insomnia, psychiatric, metabolic and cognitive disorders in ComOSAR versus OSA alone, 3) chronic obstructive airway disease (COAD) in ComOSAR versus OSA alone. OSA, RLS and insomnia were diagnosed as per respective guidelines. They were evaluated for psychiatric disorders, metabolic disorders, cognitive disorders and COAD. Results: Of 326 patients enrolled, 249 were OSA and 77 were non-OSA. 61/249 OSA patients, i.e. 24.4% had comorbid RLS, i.e. ComOSAR. RLS in non-OSA patients was similar (22/77, i.e. 28.5%); P = 0.41. ComOSAR had a significantly higher prevalence of insomnia (26% versus 10.1%; P = 0.016), psychiatric disorders (73.7% versus 48.4%; P = 0.00026) and cognitive deficits (72.1% versus 54.7%, P = 0.016) compared to OSA alone. Metabolic disorders like metabolic syndrome, diabetes mellitus, hypertension and coronary artery disease were also observed in a significantly higher number of patients with ComOSAR versus OSA alone (57% versus 34%; P = 0.0015). COAD was also seen in a significantly higher number of patients with ComOSAR compared to OSA alone (49% versus 19% respectively; P = 0.00001). Conclusion: It is essential to look for RLS in patients with OSA as it leads to a significantly higher prevalence of insomnia, and cognitive, metabolic and psychiatric disorders. COAD is also more common in ComOSAR compared to OSA alone.

Early versus non-early desaturation during 6MWT in COPD patients: A follow-up study.

Introduction: Six-minute walk test (6MWT) has a significant prognostic value in chronic obstructive pulmonary disease (COPD). Those who desaturate early during 6MWT are likely to have frequent exacerbations. Aims and Objectives: To follow-up and compare exacerbations and hospitalisations of COPD patients having early desaturation versus nonearly desaturation determined during baseline 6MWT. Methods: It was a longitudinal follow-up study conducted in a tertiary care institute from November 1, 2018 to May 15, 2020 involving 100 COPD patients. A decrease in SpO2 by ≥4% in baseline 6MWT was considered a significant desaturation. If the desaturation occurred within first minute of the 6MWT, the patient was called early desaturator (ED); if it occurred later, the patient was called nonearly desaturator (NED). If the saturation did not fall, then the patient was called nondesaturator. During the follow-up, 12 patients dropped out and 88 remained. Results: Of 88 patients, 55 (62.5%) were desaturators and 33 were nondesaturator. Of 55 desaturators, 16 were ED and 39 were NED. EDs had significantly higher number of severe exacerbations (P <.05), higher hospitalisation (P <.001), and higher BODE index (P <.01) compared to NEDs. The receptor operating characteristic curve and multiple logistic regression analysis showed that previous exacerbations, presence of early desaturation, and distance saturation product during the 6MWT were significant predictors for predicting hospitalizations. Conclusion: Early desaturation can be used as a screening tool for assessing the risk of hospitalization in COPD patients.

A Curious Case of White Out Lung.

CASE PRESENTATION: A 40-year-old Asian man with COPD presented to the ER with an acute exacerbation and type 2 respiratory failure. He was intubated and placed on the mechanical ventilator. He had a tobacco smoking history of 30 pack-years. Otherwise, he had no other significant medical or social history. The family history was non contributory. His physical development was normal.

An interesting case of whitish pleural effusion: think beyond the obvious.

A whitish pleural fluid calls for further biochemical and microbiological investigations beyond routine pleural fluid analysis as it decides the aetiology and management. https://bit.ly/3GwGpzS.

Prevalence, risk factors and effects of restless legs syndrome in COPD patients.

Restless legs syndrome (RLS), a sensory motor disorder, is commonly seen amongst chronic obstructive pulmonary disease (COPD) patients. We conducted a study to know its prevalence in COPD and analyse the possible cause and effect of RLS. It is an analytical cross-sectional study conducted between July 2016-December 2020.The prevalence of RLS was evaluated in patients of COPD using RLS diagnostic criteria. Spirometry, iron profile and arterial blood gas analysis was performed in all the patients to evaluate the cause of RLS. The effect was evaluated with diagnostic criteria for insomnia and patient health questionnaire (PHQ2) for depression. There were 205 participants with a mean age of 59±8 years, 182 (88.7%) men and 23 (11.2%) women. The mean body mass index (BMI) was 29±3.9 kg/m2. The prevalence of RLS was 31.2%. RLS was more common amongst women compared to men (60.8% vs 27.4%). RLS was more prevalent among hypoxemic (PaO2<60 mm Hg) and hypercapnic (PaCO2>45 mm Hg) patients (p<0.016; p<0.017). The ROC curve plotted between PaO2 and RLS occurrence showed that the patients having PaO2 less than 76 mm of Hg were more prone to develop RLS. RLS patients had a higher incidence of insomnia as compared to those without RLS (68.8% vs 36.8%, p<0.001). COPD with RLS patients had more depressive symptoms with a higher patient health questionnaire 2 (PHQ2) score (35.9% vs 14.2%, p<0.001) compared to non-RLS COPD patients. The multiple regression analysis also confirmed that RLS led to insomnia and depressive symptoms in COPD patients. To conclude, RLS is common in COPD patients. RLS leads to insomnia and depression, thus should be identified and treated.

A Young Man With Dyspnea.

CASE PRESENTATION: A 27-year-old accountant came to the ED with difficulty walking and progressive weakness of both lower limbs for 4 days' duration. He did not report a history of trauma or fall. He demonstrated no vertigo, headache, neck or back pain, disturbed vision, loss of weight, or weakness in upper limbs. He also reported difficulty breathing, fever, severe abdominal pain, and loose stools of 1 day's duration. His recorded maximum temperature at home was 38.3 °C. The fever subsided with oral paracetamol 500 mg. He did not report having weakness in any limb before the current presentation. He did not have comorbid diabetes mellitus or hypertension. Thirty days before presentation, he experienced fever, cough, and rhinorrhea and received a diagnosis of COVID-19 after reverse-transcriptase polymerase chain reaction testing. At that time, symptoms had been minimal, vitals signs and chest radiography findings were normal, and he had undergone home isolation. He had maintained an oxygen saturation of 98% to 99% as measured on pulse oximetry. He had not received any treatment at that time. His symptoms had lasted for 7 days, and he remained asymptomatic up to the current presentation with paraparesis.

Long-term oxygen therapy prescription in India: Evaluation of compliance, factors affecting compliance, indications, and survival.

Introduction: The international data shows that long-term oxygen therapy (LTOT) compliance is insufficient and variable. We conducted the first study from India on LTOT compliance, factors affecting compliance, indications, and survival through oxygen concentrator. Materials and Methods: Our organization from Delhi had given 378 oxygen concentrators over the last 5 years. We evaluated 120 patients randomly for participating in the study. Compliance was defined as the use of LTOT for at least 15 h/day. Results: Ninety-seven patients were included in the final analysis after exclusion criteria. The compliance to LTOT was seen in 45.36% (44/97). The commonest cause of noncompliance was lack of instructions (49.06%) followed by electricity issues, social stigma, and workplace constraints. A higher PaCO2 was associated with significantly lower compliance (PaCO2 53.18 vs. 44.98 mmHg, P = 0.036). Interstitial lung disease was associated with significantly higher compliance. Oxygen prescription was titrated with arterial blood gas analysis in only 4.12%. The indications for LTOT were chronic obstructive pulmonary disease (49.48%), posttuberculous obstructive airway disease (20.6%), and interstitial lung disease (12.37%). We found a significant reduction in the mean number of exacerbations/year from 3.91 to 1.93 (P < 0.0001). 61.86% of the patients were surviving on LTOT with a median survival time of 12 months. Conclusion: The adherence to LTOT in Indian patients is suboptimal mainly due to lack of instruction and is associated with a higher PaCO2. The practice of titration needs to be followed. The development of a national registry to monitor LTOT should be the long-term target.

A follow-up study of post infectious obliterative bronchiolitis in adults and comparative analysis with chronic obstructive pulmonary disease.

OBJECTIVES: The objective is (1) To evaluate the change in forced expiratory volume in one second (FEV1), forced vital capacity (FVC), dyspnea grading, body mass index, and oxygen saturation (SpO2) in adults with postinfectious obliterative bronchiolitis (PIOB) over a period of time (2) To evaluate the same parameters in chronic obstructive pulmonary disease (COPD) patients and compare with PIOB. MATERIALS AND METHODS: It was a retrospective observational study involving appropriately managed patients of PIOB and COPD with minimum 3 years of follow-up. Out of a total of 106 patients who followed up from January 2019 to December 2019 and had a follow-up data of more than 3 years, 61 (31 COPD and 30 PIOB) patients were included in the final analysis after applying the inclusion and exclusion criteria. RESULTS: The baseline FEV1 and FVC was significantly worse in PIOB group compared to COPD group. In PIOB group, there was nonsignificant increment in both the parameters (FVC by 18.79 ml and FEV1 by 12.2 ml per year). There was a significant decline in FVC and FEV1 in the COPD group by 106.8 ml and 63.25 ml per year, respectively. There was a significant difference between PIOB and COPD for the yearly change in FVC and FEV1 (P value being 0.000083 and 0.000033, respectively). In PIOB group, there was increment in modified Medical Research Council (mMRC) score and nonsignificant change in SpO2 whereas the SpO2 and mMRC score had a yearly decline in the COPD group. CONCLUSION: The PIOB is characterized by a nonsignificant increase in lung function whereas COPD shows a significant progressive decline.

COPD sleep phenotypes: Genesis of respiratory failure in COPD.

The chronic obstructive pulmonary disease (COPD) patients could have respiratory failure during sleep without daytime overt arterial blood gas (ABG) abnormality. We undertook a study first of its kind to attempt in distinguishing the underlying pathophysiological mechanisms.  It was a prospective observational study in stable COPD patients. The inclusion criterion was presence of day time PaO2>60 mmHg and PaCO2<45 mmHg. Twenty five out of 110 patients were excluded because of the ABG abnormality. The remaining 85 patients were subjected to overnight pulse oximetry and end-tidal (ET)-CO2 monitoring. The nocturnal oxygen desaturation was defined as per Fletcher's criteria. The nocturnal hypoventilation was defined as per American academy of sleep medicine (AASM) guidelines. Patients having saw-tooth pattern on pulse oximetry and/or snoring were subjected to polysomnography. 38/85(44.8%) patients had nocturnal gas exchange abnormality in absence of daytime respiratory failure and were identified into 3 different phenotypes: obstructive sleep apnoea (OSA), nocturnal hypoventilation and nocturnal oxygen desaturation. The isolated abnormality was seen in 24 patients: 10 patients had OSA, 9 had nocturnal hypoventilation and 5 had nocturnal oxygen desaturation. Overlap of two or more phenotypes was seen in 14 patients. As compared to the nocturnal hypoventilation and desaturation phenotypes, the OSA phenotype had a significantly higher BMI & FEV1. The nocturnal hypoventilation and the desaturation phenotypes did not have significant difference in FEV1 and BMI, but the daytime SpO2 and PaO2 differed significantly.  Such parameters could help in identifying the three distinct COPD-sleep phenotypes (OSA, nocturnal hypoventilation and nocturnal oxygen desaturation). A phenotype based nocturnal management may help in delaying the process of overt respiratory failure in COPD.

A young lady with dyspnoea: Quest for the cause.

Pulmonary hypertension (PH) is a common cause of dyspnoea. The management and prognosis of PH varies with the underlying aetiology. Hence the detection of the cause of PH is important. Obliterative bronchiolitis (OB) is a common but under-recognised cause of PH. OB is usually secondary to childhood infections known as post-infectious OB. It can also be secondary to other diseases, but cryptogenic OB is an extremely rare entity. Here we share a unique case of PH due to cryptogenic OB and its successful outcome with optimal management.

A mysterious case of an elevated dome of the right diaphragm.

Combined collapse of the right middle lobe and lower lobe requires CT scan for confirmation. Excessive dynamic airway collapse (EDAC) can cause lobar collapse. Surgical intervention is required in EDAC only in symptomatic patients with >95% collapse. https://bit.ly/2UXTuw7.

Prevalence of sleep disorders in chronic obstructive pulmonary disease and utility of global sleep assessment questionnaire: An observational case-control study.

INTRODUCTION: Although sleep disorders in chronic obstructive pulmonary disease (COPD) are common, no study has comprehensively evaluated sleep disorders in COPD, and there are no screening tools available for COPD patients. Global sleep assessment questionnaire (GSAQ) is one of the best screening tools for the general population. AIMS AND OBJECTIVES: The aims and objectives of the study were to find (i) the prevalence of sleep disorders in COPD based on GSAQ score; (ii) if the GSAQ score in COPD is high compared to healthy adult population; (iii) the prevalence of insomnia, obstructive sleep apnea (OSA), restless leg syndrome (RLS), and depression in COPD patients; and (iv) the sensitivity and specificity of GSAQ. METHODS: This was a prospective case-control study where GSAQ is administered to 100 stable COPD and 50 healthy individuals. The presence of sleep disorder in COPD was further confirmed based on the diagnostic criteria and polysomnography. RESULTS: GSAQ was positive in 68% of the COPD patients compared to 16% of the matched healthy adults (P < 0.001). The sleep disturbance was confirmed in 66 COPD patients. Insomnia, OSA, RLS, depression/anxiety, and overlap of two or more disorder were seen in 39, 13, 30, 22, and 31 patients, respectively. The overall sensitivity/specificity of GSAQ for sleep disturbances in COPD was 90.9%/70.58%, respectively. The sensitivity/specificity of GSAQ for insomnia, OSA, RLS, and anxiety/depression was 87/75%, 77/67%, 90/80%, and 91/65%, respectively. CONCLUSION: Sleep disorders in COPD patients are significantly high. GSAQ is a good screening tool for detecting the presence of disturbed sleep in COPD. Overlap of two or more sleep disorders is common in COPD.

Management of interstitial lung diseases: A consensus statement of the Indian Chest Society (ICS) and National College of Chest Physicians (NCCP).

BACKGROUND: Interstitial lung disease (ILD) is a complex and heterogeneous group of acute and chronic lung diseases of several known and unknown causes. While clinical practice guidelines (CPG) for idiopathic pulmonary fibrosis (IPF) have been recently updated, CPG for ILD other than IPF are needed. METHODS: A working group of multidisciplinary clinicians familiar with clinical management of ILD (pulmonologists, radiologist, pathologist, and rheumatologist) and three epidemiologists selected by the leaderships of Indian Chest Society and National College of Chest Physicians, India, posed questions to address the clinically relevant situation. A systematic search was performed on PubMed, Embase, and Cochrane databases. A modified GRADE approach was used to grade the evidence. The working group discussed the evidence and reached a consensus of opinions for each question following face-to-face discussions. RESULTS: Statements have been made for each specific question and the grade of evidence has been provided after performing a systematic review of literature. For most of the questions addressed, the available evidence was insufficient and of low to very low quality. The consensus of the opinions of the working group has been presented as statements for the questions and not as an evidence-based CPG for the management of ILD. CONCLUSION: This document provides the guidelines made by consensus of opinions among experts following discussion of systematic review of evidence pertaining to the specific questions for management of ILD other than IPF. It is hoped that this document will help the clinician understand the accumulated evidence and help better management of idiopathic and nonidiopathic interstitial pneumonias.

Diffuse alveolar hemorrhage secondary to plastic fume exposure: A case report.

A 31-year non-smoker man, working in plastic making industry for 12 years presented with cough and streaking hemoptysis for 2 days. Computed tomography (CT) of chest showed patchy ground glass opacities with interlobular septal thickening in bilateral lung parenchyma. Fiber optic bronchoscopy (FOB) was done. Sequential lavage was taken which showed progressively increasing hemorrhagic fluid. His diffusion capacity for carbon monoxide (DLCO) was 38.08 mL/mmHg/Mi (126%) predicted on day 2 of admission, 32.36 ml/mmHg/Mi (106%) predicted on discharge and 39.63 mL/mmHg/Mi (130%) predicted on going back to work. He was diagnosed with plastic fume exposure related pulmonary alveolar hemorrhage.

Management of interstitial lung diseases: A consensus statement of the Indian Chest Society (ICS) and National College of Chest Physicians (NCCP)

Interstitial lung disease (ILD) is a complex and heterogeneous group of acute and chronic lung diseases of several known and unknown causes. While clinical practice guidelines (CPG) for idiopathic pulmonary fibrosis (IPF) have been recently updated, CPG for ILD other than IPF are needed. Methods: A working group of multidisciplinary clinicians familiar with clinical management of ILD (pulmonologists, radiologist, pathologist, and rheumatologist) and three epidemiologists selected by the leaderships of Indian Chest Society and National College of Chest Physicians, India, posed questions to address the clinically relevant situation. A systematic search was performed on PubMed, Embase, and Cochrane databases. A modified GRADE approach was used to grade the evidence. The working group discussed the evidence and reached a consensus of opinions for each question following face-to-face discussions. Results: Statements have been made for each specific question and the grade of evidence has been provided after performing a systematic review of literature. For most of the questions addressed, the available evidence was insufficient and of low to very low quality. The consensus of the opinions of the working group has been presented as statements for the questions and not as an evidence-based CPG for the management of ILD. Conclusion: This document provides the guidelines made by consensus of opinions among experts following discussion of systematic review of evidence pertaining to the specific questions for management of ILD other than IPF. It is hoped that this document will help the clinician understand the accumulated evidence and help better management of idiopathic and nonidiopathic interstitial pneumonias.

A novel procedure of endobronchial ultrasound-guided transbronchial needle aspiration for pulmonary parenchymal lesions: The ZUTAM technique.

Convex probe-endobronchial ultrasound (CP-EBUS) has been proven to be safe and accurate for identifying malignancy and granulomatous disease affecting the mediastinum and hilum. CP-EBUS can be used for intraparenchymal lesions also and has been shown to be efficacious. A subset of lesions particularly suited for CP-EBUS are those completely surrounded by lung parenchyma, centrally located, and typically close to but without an airway leading directly to them. We report a case of transbronchial needle aspiration (TBNA) done from a nodule of size 11 mm in the superior segment of the right lower lobe. EBUS-TBNA was done from this lesion, which was 5 mm away from the bronchus in the lung parenchyma with intervening normal lung tissue in between. TBNA was performed by compressing the abutting normal lung tissue, thus causing compression collapse of the intervening normal lung. We labeled this Zealous Unique Trans Arterial Maneuver as the "ZUTAM" technique.