Pulmonary Function Tests: A Tool to Assess the Lung Functional Capacity in Different Physiological and Disease Conditions | Chapter 10 | Medical Science: Updates and Prospects Vol. 7

 

Pulmonary function tests are tests to assess pulmonary function. These tests assess every aspect of our lung function. It assesses lung compliance (dynamic as well as static), degree of airflow obstruction, exchange of gases and other functions. Pulmonary function tests are non-invasive and safe, as there is no requirement of insertion of any instrument inside the human body by a health care provider. The study evaluates the importance of Pulmonary Function Tests to assess the Lung Functional Capacity in different physiological and disease conditions. There is a battery of tests to assess both static and dynamic lung function. Dynamic lung function tests mainly measure airflow rate, while static lung function tests measure absolute air volumes. Some tests are used to measure how well our lungs absorb oxygen in blood. Some others test the response of lungs to some triggers, like exercise and pharmacologic agents. Pulmonary function tests are variable in different physiological states like age, sex, exercise, change of posture, pregnancy, etc., as well as in pulmonary diseases. Pulmonary diseases are broadly classified into two categories: first, restrictive lung diseases, e.g. interstitial lung disease, scoliosis, etc. and second, obstructive lung diseases, e.g. asthma, bronchitis, bronchiectasis, etc. In obstructive lung diseases, mainly dynamic lung functions are affected, but in restrictive lung diseases, static lung functions are mainly affected. FEF25-75% is the most sensitive parameter for early diagnosis of obstructive lung disease, whereas DLCO is the most sensitive for early diagnosis of restrictive lung disease.

 

 

Author(s) Details

Mohd. Amir
Faculty of Medicine, Aligarh Muslim University (AMU), Aligarh, India.

 

Please see the book here :- https://doi.org/10.9734/bpi/msup/v7/7252

Comprehensive Clinical Insights into the Diagnosis, Management and Complications of Pickwickian Syndrome | Chapter 8 | Medical Science: Updates and Prospects Vol. 2

 

The aim of this study is to provide a comprehensive and up-to-date synthesis of the clinical understanding of Pickwickian Syndrome, with a focus on its diagnosis, management, and associated complications. Pickwickian Syndrome, or Obesity Hypoventilation Syndrome (OHS), is a serious obesity-related respiratory disorder defined by chronic daytime hypercapnia (PaCO₂ > 45 mmHg), obesity (BMI ≥ 30 kg/m²), and exclusion of other hypoventilation causes. It arises from a complex interplay of impaired ventilatory drive, leptin resistance, and mechanical respiratory restriction, often coexisting with obstructive sleep apnea (OSA) in nearly 90% of cases. OHS leads to chronic hypoxemia, pulmonary hypertension, and cor pulmonale if untreated. Diagnosis relies on arterial blood gas analysis, polysomnography, and exclusion of alternative etiologies. A key diagnostic feature is chronic hypercapnia (PaCO₂ >45 mmHg), often accompanied by compensated metabolic alkalosis due to renal bicarbonate retention.  There may also be hypoxemia (PaO₂ <70 mmHg), particularly in more severe cases. Management requires a multidisciplinary approach emphasising weight reduction, lifestyle modification, and positive airway pressure (PAP) therapy—CPAP for OHS with OSA and BiPAP for persistent hypercapnia. Bariatric surgery offers substantial improvement in severe cases. Pharmacologic agents like acetazolamide and medroxyprogesterone serve limited roles. Early recognition and adherence to therapy markedly improve outcomes, reducing mortality from 30% to under 10%. Despite advancements, OHS remains underdiagnosed and undertreated, highlighting the need for greater clinical awareness, digital monitoring integration, and personalised management strategies.

 

 

Author(s) Details

Harsahaj Singh Wilkhoo
Faculty of Medicine, Tbilisi State Medical University, Tbilisi, Georgia.

 

Afra Wasama Islam
Faculty of Medicine, Tbilisi State Medical University, Tbilisi, Georgia.

 

Please see the book here :- https://doi.org/10.9734/bpi/msup/v2/6708