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.

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.

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.

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.

Consensus & Evidence-based INOSA Guidelines 2014 (First edition).

Obstructive sleep apnoea (OSA) and obstructive sleep apnoea syndrome (OSAS) are subsets of sleep-disordered breathing. Awareness about OSA and its consequences amongst the general public as well as the majority of primary care physcians across India is poor. This necessiated the development of the INdian initiative on Obstructive Sleep Apnoea (INOSA) guidelines under the auspices of Department of Health Research, Ministry of Health & Family Welfare, Government of India. OSA is the occurrence of an average five or more episodes of obstructive respiratory events per hour of sleep with either sleep related symptoms or comorbidities or ≥ 15 such episodes without any sleep related symptoms or comorbidities. OSAS is defined as OSA associated with daytime symptoms, most often excessive sleepiness. Patients undergoing routine health check-up with snoring, daytime sleepiness, obesity, hypertension, motor vehicular accidents and high risk cases should undergo a comprehensive sleep evaluation. Medical examiners evaluating drivers, air pilots, railway drivers and heavy machinery workers should be educated about OSA and should comprehensively evaluate applicants for OSA. Those suspected to have OSA on comprehensive sleep evaluation should be referred for a sleep study. Supervised overnight polysomnography (PSG) is the "gold standard" for evaluation of OSA. Positive airway pressure (PAP) therapy is the mainstay of treatment of OSA. Oral appliances are indicated for use in patients with mild to moderate OSA who prefer oral appliances to PAP, or who do not respond to PAP or who fail treatment attempts with PAP or behavioural measures. Surgical treatment is recommended in patients who have failed or are intolerant to PAP therapy.

Bronchodilator efficacy of tiotropium-formoterol via single pressurized meter dose inhaler (pMDI) versus tiotropium alone in COPD.

BACKGROUND: Bronchodilators form the main stay of treatment for COPD. When symptoms are not adequately controlled with one bronchodilator, addition of another bronchodilator is recommended. We have recently developed a combination of tiotropium and formoterol in a single pressurized metered dose inhaler (pMDI) (Cipla Ltd., India). The aim of this study was to compare the bronchodilator effects of a single dose of 18 mcg of tiotropium versus a single dose of a combination of 18 mcg tiotropium plus 12 mcg formoterol administered via a pMDI in subjects with moderate-to-severe COPD. STUDY DESIGN: 44 COPD subjects were enrolled in this randomized, double-blind, multi-centre, cross-over study. 18 mcg tiotropium and 18 mcg tiotropium plus 12 mcg formoterol were administered via pressurized metered dose inhalers on two separate days. FEV(1), FVC and Inspiratory capacity (IC) were measured before, 15, 30 min, 1, 2, 3, 4, 6, 8, 12 and 24 h after the study drugs were administered. RESULTS: Compared with tiotropium alone, a combination of tiotropium plus formoterol showed a faster onset of bronchodilator response (p < 0.01 for FEV(1) and FVC), a greater mean maximum change in FEV(1) (p = 0.01) and FVC (p = 0.008) and greater AUC(0-24h) values for FEV(1), FVC and IC. Trough FEV(1) and FVC values were also greater in the combination group. CONCLUSION: A combination of tiotropium plus formoterol administered via a single inhaler produced a superior bronchodilator response than tiotropium alone over a period of 24 h.

Consensus & evidence-based INOSA Guidelines 2014 (first edition).

Obstructive sleep apnoea (OSA) and obstructive sleep apnoea syndrome (OSAS) are subsets of sleep-disordered breathing. Awareness about OSA and its consequences amongst the general public as well as the majority of primary care physcians across India is poor. This necessiated the development of the INdian initiative on Obstructive sleep apnoea (INOSA) guidelines under the auspices of Department of Health Research, Ministry of Health & Family Welfare, Government of India. OSA is the occurrence of an average five or more episodes of obstructive respiratory events per hour of sleep with either sleep related symptoms or co-morbidities or ≥ 15 such episodes without any sleep related symptoms or co-morbidities. OSAS is defined as OSA associated with daytime symptoms, most often excessive sleepiness. Patients undergoing routine health check-up with snoring, daytime sleepiness, obesity, hypertension, motor vehicular accidents and high risk cases should undergo a comprehensive sleep evaluation. Medical examiners evaluating drivers, air pilots, railway drivers and heavy machinery workers should be educated about OSA and should comprehensively evaluate applicants for OSA. Those suspected to have OSA on comprehensive sleep evaluation should be referred for a sleep study. Supervised overnight polysomnography (PSG) is the "gold standard" for evaluation of OSA. Positive airway pressure (PAP) therapy is the mainstay of treatment of OSA. Oral appliances are indicated for use in patients with mild to moderate OSA who prefer oral appliances to PAP, or who do not respond to PAP or who fail treatment attempts with PAP or behavioural measures. Surgical treatment is recommended in patients who have failed or are intolerant to PAP therapy.

Evaluation of Diagnostic Performance of Line Probe Assay on Smear-Negative Samples of Pulmonary Tuberculosis.

BACKGROUND: This study aims to compare the performance of line probe assay (LPA) on smear-negative samples with that of smear-positive samples for diagnosing pulmonary tuberculosis (PTB) and first-line drug sensitivity testing (FL DST). METHODS: A total of 196 sputum samples including both smear-positive (112) and negative (84) samples of patients suspected of PTB were subjected to LPA for TB detection and FL DST. TB culture followed by MPT 64 Ag was done and conventional FL DST was performed on all culture-positive isolates. Results of LPA on smear-negative were compared with smear-positive samples. RESULTS: The LPA confirmed the diagnosis of PTB in 104/112 smear-positive cases but in only 36/84 smear-negative cases. The assay had 47.36%, 72.72%, and 88.88% sensitivity and 86.96%, 95.23%, and 95.65% specificity in smear-negative cases compared to 89.09%, 95.83%, and 98.07% sensitivity and 100%, 98.36%, and 98.24% specificity in smear-positive cases for detecting Mycobacterium tuberculosis (MTB), rifampicin (RMP) resistance, and isoniazid (INH) resistance, respectively. CONCLUSION: LPA performance was better on smear-positive than smear-negative sputum samples. Further larger studies are needed to justify the use of LPA on smear-negative pulmonary samples for diagnosis.

Follow-up study of COVID-19 sequelae (FOSCO study).

INTRODUCTION: We undertook the first study from India to evaluate the long-term health effects of coronavirus disease 2019 (COVID-19). METHODS: The patients enrolled in our post-COVID-19 clinic were followed up for assessment at 1, 3, 6 and 12 months after recovery from acute disease prospectively. RESULTS: 200 patients with mean age of 50.72 years and 57.5% males were analysed. 42.5% had severe and 17% had moderate disease at the time of diagnosis. The persistence of symptoms beyond 1 month of diagnosis was seen in 72.5% (145/200) patients. 8% (16/200) of the patients had post-COVID-19 complications that required rehospitalisation after discharge or recovery from acute COVID-19. The complications included respiratory failure (2%), lung cavities (3.5%), fungal infection, pericardial effusion, pneumothorax and death. The symptoms were persistent beyond 3 months in 51% (102/200) and beyond 6 months in 17.5% (35/200) of cases. The patients with persistent symptoms beyond 3 months and 6 months had significantly higher intensive care unit (ICU) admission during acute COVID-19, severe disease during acute COVID-19, and higher prevalence of comorbidities compared to the recovered patients. The clinical recovery was attained in 95.5% (91/200) patients, and the radiological recovery was attained in 97.92% patients at 1 year. The mean duration to clinical recovery was 174.2 days. CONCLUSIONS: COVID-19 recovery takes longer time. However, clinico-radiological recovery is attained in >95% cases by one year.

NCCP-ICS joint consensus-based clinical practice guidelines on medical thoracoscopy.

ABSTRACT: Medical Thoracoscopy (MT) is commonly performed by respiratory physicians for diagnostic as well as therapeutic purposes. The aim of the study was to provide evidence-based information regarding all aspects of MT, both as a diagnostic tool and therapeutic aid for pulmonologists across India. The consensus-based guidelines were formulated based on a multistep process using a set of 31 questions. A systematic search of published randomized controlled clinical trials, open labelled studies, case reports and guidelines from electronic databases, like PubMed, EmBase and Cochrane, was performed. The modified grade system was used (1, 2, 3 or usual practice point) to classify the quality of available evidence. Then, a multitude of factors were taken into account, such as volume of evidence, applicability and practicality for implementation to the target population and then strength of recommendation was finalized. MT helps to improve diagnosis and patient management, with reduced risk of post procedure complications. Trainees should perform at least 20 medical thoracoscopy procedures. The diagnostic yield of both rigid and semirigid techniques is comparable. Sterile-graded talc is the ideal agent for chemical pleurodesis. The consensus statement will help pulmonologists to adopt best evidence-based practices during MT for diagnostic and therapeutic purposes.

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.

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.

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.

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.

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.

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.