Chronic Obstructive Pulmonary Disease and Oxygen Therapy: A Double-edged Sword.

Oxygen, like all medicines, is a drug which needs moderation. Hypoxia, as well as excess oxygen supplementation, can be harmful in a patient with chronic obstructive pulmonary disease (COPD). Both the European and the British guidelines recommend a target oxygen saturation of 88-92% in patients with COPD. Hypoxia can result in symptoms, such as restlessness, anxiety, agitation, and headache, while excess oxygen can lead to altered sensorium due to the retention of carbon dioxide (CO2) in patients with COPD. We often come across patients who come with breathlessness and have hypoxia, and the knee-jerk reaction is to start the patient on oxygen support to maintain an oxygen saturation of >95%, and this may result in hypercapnia and type II respiratory failure. Here, we present a descriptive review of the proper application of oxygen therapy in a patient presenting with acute exacerbation of COPD, the rationale behind the target oxygen saturations, and the mechanisms of type II respiratory failure due to hyperoxygenation.

Langerhans Cell Histiocytosis Presenting with Pneumothorax and Diabetes Insipidus.

Secondary spontaneous pneumothoraces occur in patients with known underlying lung disease. Patients with emphysema, bullae, and cystic lesions in the lungs are at high risk of developing pneumothorax. Cystic lung diseases like Langerhans cell histiocytosis (LCH) can present with complications like pneumothorax. Other common presenting features include maculopapular rashes and bone lesions. It can also be associated with endocrinopathies, most commonly central diabetes insipidus (CDI). We here present a case of a 22-year-old male who presented with pneumothorax, polyuria, and polydipsia. He was diagnosed with LCH on transbronchial lung biopsy, associated with CDI, and was treated with thoracoscopy-guided autologous blood patch for persistent air leak and subcutaneous cytarabine.

Clinical characteristics of non-sleepy obstructive sleep apnea patients: a study in a tertiary care sleep clinic in India.

Obstructive sleep apnea (OSA) encompasses a diverse population, manifesting with or without symptoms of excessive daytime sleepiness. There is contention surrounding the significance of non-sleepy OSA within clinical contexts and whether routine treatment is warranted. This study aims to evaluate epidemiological and clinical distinctions between sleepy and non-sleepy OSA patients. A retrospective analysis was conducted on consecutive patients undergoing polysomnography for OSA assessment at tertiary care hospitals between 2018 and 2023. For 176 of 250 patients, complete polysomnography records with OSA diagnoses were available. Non-sleepy OSA was defined when a patient had an Epworth sleepiness scale score <10 and polysomnography demonstrated an apnea hypopnea index ≥5/hour. Non-sleepy OSA patients were matched with sleepy OSA patients in terms of age and gender distribution (mean age 51.24±13.25 years versus 50.9±10.87 years, male 70.4% versus 73.3%). The sensitivity of STOP-BANG≥3 for the non-sleepy OSA group was 87.7%, 89.3%, and 95.2% for any OSA severity, moderate to severe OSA, and severe OSA, respectively, while the corresponding sensitivity for the sleepy OSA group was 96.5%, 98.6%, and 100% for any OSA severity, moderate to severe OSA, and severe OSA, respectively. A novel symptom scoring tool, HASSUN (hypertension, nocturnal apneas, snoring, sleep disturbance, unrefreshing sleep, and nocturia), demonstrated a sensitivity of over 90% for all severity categories of OSA in both non-sleepy and sleepy OSA groups. The prevalence of cardiovascular and metabolic comorbidities did not significantly differ between non-sleepy and sleepy OSA patients. The physiological parameters, including forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC ratio, arterial partial pressure of oxygen, and bicarbonate at baseline, were comparable between the two groups. To conclude, non-sleepy OSA patients are less obese, exhibit fewer symptoms, and have less severe OSA in comparison to sleepy OSA. Non-sleepy OSA patients display a similar likelihood of cardiovascular and metabolic comorbidities compared to sleepy OSA patients. Further investigations are warranted to elucidate the mechanisms underlying cardiovascular metabolic comorbidities in non-sleepy OSA patients. The proposed HASSUN scoring tool for non-sleepy OSA screening necessitates validation in future studies.

Radial Endobronchial Ultrasound to Diagnose a Case of Non-Hodgkin's Lymphoma in the Lung: A Case Report and Literature Review.

Non-Hodgkin's lymphomas (NHLs) are a heterogeneous group of lymphoproliferative malignancies that are very rarely seen in the lung. Although they generally have a favorable prognosis, the clinical symptoms and most efficient methods of diagnosis have not yet been clearly defined. This report highlights an interesting case wherein a 75-year-old male who presented with complaints of fever, cough, and generalized weakness for three weeks was diagnosed and treated as a case of pneumonia. He did not respond to conventional treatment with antibiotics and antipyretics. Hence, computed tomography of the thorax was done which showed consolidation in the right lower lobe along with a few enlarged right hilar nodes. To evaluate this unresolved pneumonia, he was further evaluated with a radial endobronchial ultrasound (EBUS) and biopsy, which helped in arriving at a diagnosis of NHL. This case illustrates the significance of advanced interventions such as radial EBUS to identify the exact etiology of the lesions. This is the first case to document the ultrasound images of NHL in the lung, obtained using a radial EBUS.

Author Response.

How to cite this article: Ramaswamy A, Kumar R, Ish P, Gupta N. Author Response. Indian J Crit Care Med 2024;28(4):405.

Thoracoscopic blood patch instillation for persistent air leak in pneumothorax: a case series and systematic review.

Persistent air leaks in patients with pneumothorax can lead to significant morbidity. If a patient with persistent air leak is medically unfit for thoracic surgery, medical pleurodesis via chest tube or thoracoscopy is either an option. Thoracoscopy offers the advantage of visualizing the site of the air leak and enabling direct instillation of the pleurodesis agent or glue at that location. Autologous blood patch instillation via chest tube has been reported to be a cheap and very effective technique for the management of persistent air leaks. However, thoracoscopic blood patch instillation has not been reported in the literature. We report two cases of secondary spontaneous pneumothorax in which patients had persistent air leaks for more than seven days and were subjected to thoracoscopy to locate the site of the leak. In the same sitting, 50 mL of autologous blood patch was instilled directly at the leak site. Post-procedure, the air leak subsided in both patients, and the chest tube was removed with complete lung expansion. We also conducted a systematic review of the use of medical thoracoscopic interventions for treating persistent air leaks.

HAT and HDAC: Enzyme with Contradictory Action in Neurodegenerative Diseases.

In view of the increasing risk of neurodegenerative diseases, epigenetics plays a fundamental role in the field of neuroscience. Several modifications have been studied including DNA methylation, histone acetylation, histone phosphorylation, etc. Histone acetylation and deacetylation regulate gene expression, and the regular activity of histone acetyltransferases (HATs) and histone deacetylases (HDACs) provides regulatory stages for gene expression and cell cycle. Imbalanced homeostasis in these enzymes causes a detrimental effect on neurophysiological function. Intriguingly, epigenetic remodelling via histone acetylation in certain brain areas has been found to play a key role in the neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease. It has been demonstrated that a number of HATs have a role in crucial brain processes such regulating neuronal plasticity and memory formation. The most recent therapeutic methods involve the use of small molecules known as histone deacetylase (HDAC) inhibitors that antagonize HDAC activity thereby increase acetylation levels in order to prevent the loss of HAT function in neurodegenerative disorders. The target specificity of the HDAC inhibitors now in use raises concerns about their applicability, despite the fact that this strategy has demonstrated promising therapeutic outcomes. The aim of this review is to summarize the cross-linking between histone modification and its regulation in the pathogenesis of neurological disorders. Furthermore, these findings also support the notion of new pharmacotherapies that target particular areas of the brain using histone deacetylase inhibitors.

Cryodebulking to Relieve Critical Airway Narrowing Due to a Central Airway Tumor at the Carina: A Case Report and Literature Review.

Central airway tumors presenting as critical airway stenosis is a medical emergency. Employing a cryoprobe, we successfully debulked a central airway tumor, providing rapid relief to a patient who came to the emergency room with severe breathlessness, hemoptysis, and respiratory failure. The current report underscores the efficacy of cryodebulking as an immediate and minimally invasive technique and a compelling alternative to conventional heat-based therapies.

Correlation of severity & clinical outcomes of COVID-19 with virus variants: A prospective, multicentre hospital network study.

BACKGROUND OBJECTIVES: The clinical course of COVID-19 and its prognosis are influenced by both viral and host factors. The objectives of this study were to develop a nationwide platform to investigate the molecular epidemiology of SARS-CoV-2 (Severe acute respiratory syndrome Corona virus 2) and correlate the severity and clinical outcomes of COVID-19 with virus variants. METHODS: A nationwide, longitudinal, prospective cohort study was conducted from September 2021 to December 2022 at 14 hospitals across the country that were linked to a viral sequencing laboratory under the Indian SARS-CoV-2 Genomics Consortium. All participants (18 yr and above) who attended the hospital with a suspicion of SARS-CoV-2 infection and tested positive by the reverse transcription-PCR method were included. The participant population consisted of both hospitalized as well as outpatients. Their clinical course and outcomes were studied prospectively. Nasopharyngeal samples collected were subjected to whole genome sequencing to detect SARS-CoV-2 variants. RESULTS: Of the 4972 participants enrolled, 3397 provided samples for viral sequencing and 2723 samples were successfully sequenced. From this, the evolution of virus variants of concern including Omicron subvariants which emerged over time was observed and the same reported here. The mean age of the study participants was 41 yr and overall 49.3 per cent were female. The common symptoms were fever and cough and 32.5 per cent had comorbidities. Infection with the Delta variant evidently increased the risk of severe COVID-19 (adjusted odds ratio: 2.53, 95% confidence interval: 1.52, 4.2), while Omicron was milder independent of vaccination status. The independent risk factors for mortality were age >65 yr, presence of comorbidities and no vaccination. INTERPRETATION CONCLUSIONS: The authors believe that this is a first-of-its-kind study in the country that provides real-time data of virus evolution from a pan-India network of hospitals closely linked to the genome sequencing laboratories. The severity of COVID-19 could be correlated with virus variants with Omicron being the milder variant.

Comparative yield of transbronchial cryo-nodal biopsy, transbronchial intra-nodal forceps biopsy, and transbronchial needle aspiration for mediastinal lesions at a tertiary care center in India (COLD-FORCEPS study).

Endobronchial ultrasound (EBUS) guided mediastinal cryobiopsy, and intranodal forceps biopsy are newer modalities for sampling mediastinal lymph nodes. The data regarding the diagnostic yield of both modalities is scarce. Patients were recruited retrospectively from our existing database. Patients who had undergone both an EBUS guided mediastinal cryobiopsy and an intranodal forceps biopsy were enrolled in the study. The final diagnosis was made with a clinical-pathological-radiological assessment and clinico-radiological follow-up after one month. A total of 34 patients were enrolled in the study who had undergone both EBUS guided mediastinal cryobiopsy and intranodal forceps biopsy and had complete data available, including 1-month follow-up data. The sample adequacy rate of EBUS-transbronchial needle aspiration (EBUS-TBNA), EBUS-TBNA with mediastinal cryobiopsy, and EBUS-TBNA with intranodal forceps biopsy was 94.11%, 97.05%, and 94.11%, respectively (p=0.56). The diagnostic yield achieved in EBUS-TBNA, EBUS-TBNA with mediastinal cryobiopsy, and EBUS-TBNA with intranodal forceps biopsy was 73.52%, 82.35%, and 79.41%, respectively (p=0.38). No major complications were seen in any patient. To conclude, adding EBUS guided mediastinal cryobiopsy and intranodal forceps biopsy to EBUS-TBNA may not be superior to routine EBUS-TBNA.

Simulated Hemoptysis - Difficulties in Diagnosis / Hemoptisis facticia - dificultades en el diagnóstico

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