Haemodynamic effects of non-invasive ventilation in patients with obesity-hypoventilation syndrome.
OBJECTIVE
Although it has been reported that pulmonary hypertension is more frequent in patients with obesity-hypoventilation syndrome than in patients with 'pure' obstructive sleep apnoea syndrome, little is known about the haemodynamic repercussions of this entity. The aim was to describe the haemodynamic status, as assessed by echocardiography and 6-min walk test (6MWT), of patients with a newly diagnosed, most severe form of obesity-hypoventilation syndrome, and to evaluate the impact of non-invasive ventilation in these patients.


METHODS
A prospective, descriptive, and single-centre follow-up study was conducted. At baseline, patients underwent echocardiography, spirometry, static lung volume measurement, 6MWT, overnight pulse-oximetry and polygraphic recording. Changes in echocardiography and 6MWT were assessed after 6 months of non-invasive ventilation. Right ventricular overload was defined on the basis of right ventricular dilatation, hypokinesis, paradoxical septal motion and/or pulmonary hypertension.


RESULTS
Thirty patients (20 women; mean age 69 ± 11) were tested. The percentage of patients with right ventricular overload did not change significantly after non-invasive ventilation (43.3-41.6%; P = 0.24). In patients with right ventricular overload at diagnosis, pulmonary artery systolic pressure decreased significantly at six months (58 ± 11 to 44 ± 12 mm Hg; P = 0.014), and mean distance on 6MWT increased from 350 ± 110 to 426 ± 78 m (P = 0.006), without significant changes in body mass index.


CONCLUSIONS
Right ventricular overload is a frequent finding in patients with the most severe form of obesity-hypoventilation syndrome. Treatment with non-invasive ventilation is associated with a decrease in pulmonary artery systolic pressure at six months and an increase in the distance covered during the 6MWT.
Respiratory Division and Sleep Disorders Unit, Hospital Lucus Augusti, Lugo, Spain. olalla.castro.anon@sergas.es
Olalla
O
Castro-Añón
Rafael
R
Golpe
Luis A
LA
Pérez-de-Llano
María Jesús
MJ
López González
Edgar J
EJ
Escalona Velasquez
Ruth
R
Pérez Fernández
Ana
A
Testa Fernández
Arturo
A
González Quintela
D000368:Aged; D000369:Aged, 80 and over; D004452:Echocardiography / Q000379:methods; D005080:Exercise Test; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000503:physiopathology; D008875:Middle Aged; D063087:Noninvasive Ventilation / Q000379:methods*; D010845:Obesity Hypoventilation Syndrome / Q000503:physiopathology* / Q000628:therapy*; D010092:Oximetry / Q000379:methods; D017286:Polysomnography / Q000379:methods; D012129:Respiratory Function Tests / Q000295:instrumentation / Q000379:methods; D012720:Severity of Illness Index; D018497:Ventricular Dysfunction, Right / Q000503:physiopathology / Q000628:therapy