Abstract
Aims:
In a patient with chronic pulmonary disease (COPD), obesity has many detrimental effects on the respiratory function and may lead to chronic hypoventilati´on in some patients, an association known as the obesity-hypoventilation syndrome (OHS). In many cases, patients with OHS also have sleep apnoeas. The association of Obstructive sleep apnoea syndrome (OSAS) and COPD, also known as Overlap syndrome.
Design:
History: A 65-year-old-man presented a chronic pulmonary disease (COPD) and at the moment, they had mild-to-moderate degrees of restrictive ventilatory pattern due to obesity, and clinical data suggesting that obstructive sleep apnoea syndrome (OSAS).
Methods:
Gasometric values, Quetelet index, Clinical data, pulmonary function test results, and pulmonary haemodynamics and polysomnographic characteristics were obtained.
Results:
Clinical data: diurnal sleep, dyspnoea and morning headache Gasometric values (diurnal): pO263 mmHg, Hypoxia and Hypercapnia. Desaturation Quetelet Index: 35’15. Critic Obesity Pulmonary function test results: Obstructive pattern and restrictive ventilatory pattern Polysomnographic characteristics: Obstructive sleep apnea.
Discussion:
In patients with OHS plus OSAS, the average proportion of obstructive apnoeas was 75% and central hypopnoeas 25%, which corresponded to prolonged periods of hypoventilation. Some patients with severe OSAS might have daytime hypercapnia, especially in the case of excessive daytime sleepiness. The mechanisms that link obesity and hypoventilation are unknown, but are thought to imply a depressed central control of the ventilatory drive. The OHS patients were significantly older than patients with pure OSAS.
Conclusions:
1- Patients with OSAS and chronic respiratory insufficiency had in most cases an associated OHS or COPD
2- Patients with OHS, like patients with the association of OSAS plus COPD, exhibited many features of poor prognosis, such as severe hypoxemia, hypercapnia, and pulmonary hypertension
3- Patients with OHS were older than patients with pure OSAS. They had mild-to-moderate degrees of restrictive ventilatory pattern due to obesity; and severe gas exchange impairment and pulmonary hypertension were quite frequent
4- The association of OHS with OSAS was the rule
Conflict of interest and funding
None.
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