All of the following criteria are used for diagnosis of obesity hypoventilation syndrome except
**Core Concept**
Obesity hypoventilation syndrome (OHS) is a condition where obesity leads to impaired respiratory function, resulting in chronic hypoventilation. It is characterized by excessive daytime sleepiness, obesity, and impaired lung function.
**Why the Correct Answer is Right**
The diagnosis of OHS involves the evaluation of several clinical criteria, including:
- Obesity, typically defined as a body mass index (BMI) of 30 or higher
- Chronic daytime hypercapnia (elevated CO2 levels in the blood)
- Chronic daytime hypoxemia (low oxygen levels in the blood)
- Polysomnography (PSG) findings consistent with sleep-disordered breathing, such as obstructive sleep apnea (OSA)
- Exclusion of other causes of hypoventilation, such as neuromuscular disease or chronic obstructive pulmonary disease (COPD)
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not mentioned in the correct criteria for diagnosing OHS. **Option A:** is actually one of the correct criteria.
* **Option C:** This is a potential consequence of OHS, not a diagnostic criterion. **Option C:** is a complication of OHS rather than a diagnostic feature.
* **Option D:** This is another potential consequence of OHS, not a diagnostic criterion. **Option D:** is a complication of OHS rather than a diagnostic feature.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that OHS is often underdiagnosed, and its diagnosis should be considered in patients with obesity, especially those with symptoms of sleep-disordered breathing.
**Correct Answer:** A.