Obesity Hypoventilation Syndrome (Pickwickian Syndrome)
OHS is a breathing disorder seen in some people who are obese that leads to low oxygen levels and too much carbon dioxide in your blood. Low oxygen and high carbon dioxide levels may develop because of a condition called hypoventilation. Hypoventilation means you are not moving enough air in and out of your lungs.
The three main features of OHS are:
- daytime hypoventilation
- sleep disordered breathing (such as obstructive sleep apnea)
OHS has also been called Pickwickian Syndrome because a character described by the famous author Charles Dickensin his novel, The Posthumous Papers of the Pickwick Club,has similar OHS symptoms.
In obesity-hypoventilation syndrome, alveolar hypoventilation appears to result from a combination of blunted ventilatory drive and increased mechanical load imposed upon the chest by obesity. Voluntary hyperventilation returns the Pco2 and the Po2 toward normal values, a correction not seen in lung diseases causing chronic respiratory failure, such as COPD. Most patients with obesity-hypoventilation syndrome also suffer from obstructive sleep apnea, which must be treated aggressively if identified as a comorbid disorder.
The symptoms of OHS are usually caused by a lack of sleep and a lower than normal oxygen level in your blood. Symptoms can include:
- Daytime—sleepiness, lack of energy, breathlessness, headache, depression
- Nighttime—loud and frequent snoring during sleep and/or breathing pauses when you stop breathing for short periods of time
These may be concerning to your bed partner. Your bed partner may be the only one who sees or hears your nighttime symptoms.
Therapy of obesityhypoventilation syndrome consists mainly of weight loss, which improves hypercapnia and hypoxemia as well as the ventilatory responses to hypoxia and hypercapnia. NIPPV is helpful in some patients. Respiratory stimulants may be helpful and include progesterone acetate, 10–20 mg every 8 hours orally, theophylline, and acetazolamide.