Basoglu OK, Tasbakan MS. Comparison of clinical characteristics in patients
with obesity hypoventilation syndrome and obese obstructive sleep apnea syndrome:
a case-control study. Clin Respir J. 2013 Sep 13.
It was shown that OHS patients have increased rate of hypertension, daytime sleepiness and HCO3 , and decreased lung functions and PaO2 levels than OSAS patients. The present results support that elevated bicarbonate levels and decreased oxygen saturations in obese OSAS patients should prompt clinicians to predict OHS.
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Some learning points:
- OHS, or cardiopulmonary syndrome, is almost certainly under-recognized and under-reported in the paediatric age group.
- Children with OHS have severe obesity and experience sleep-disordered breathing (usually obstructive sleep apnoea and/or nocturnal hypoventilation), resulting in excessive daytime drowsiness, with decreased attention and intellectual functioning adversely affecting their learning ability, as well as compounding the metabolic consequences of obesity.
- If nocturnal hypoventilation is untreated, major complications can include polycythemia, cor pulmonale, congestive heart failure, respiratory failure and even death.
- OHS treatment mainly consists of weight reduction plus BiPAP non-invasive ventilation support, taking into account that compliance is difficult in the paediatric population (3–6).
- The long-term success rate for adenotonsillectomy in obese children is low in the absence of effective weight loss; this therapy should still be considered if there is some degree of hypertrophy but should not be the default treatment (3–6).
Chau EH, Lam D, Wong J, Mokhlesi B, Chung F. Obesity hypoventilation syndrome:
a review of epidemiology, pathophysiology, and perioperative considerations.
Anesthesiology. 2012 Jul;117(1):188-205.
Obesity hypoventilation syndrome (OHS) is defined by the triad of obesity, daytime hypoventilation, and sleep-disordered breathing without an alternative neuromuscular, mechanical, or metabolic cause of hypoventilation. It is a disease entity distinct from simple obesity and obstructive sleep apnea. OHS is often undiagnosed but its prevalence is estimated to be 10-20% in obese patients with obstructive sleep apnea and 0.15-0.3% in the general adult population. Compared with eucapnic obese patients, those with OHS present with severe upper airway obstruction, restrictive chest physiology, blunted central respiratory drive, pulmonary hypertension, and increased mortality. The mainstay of therapy is noninvasive positive airway pressure. Currently, information regarding OHS is extremely limited in the anesthesiology literature. This review will examine the epidemiology, pathophysiology, clinical characteristics, screening, and treatment of OHS. Perioperative management of OHS will be discussed last.
Mokhlesi B. Obesity hypoventilation syndrome: a state-of-the-art review.
Respir Care. 2010 Oct;55(10):1347-62; discussion 1363-5.
Obesity hyoventilation syndrome (OHS) is defined as the triad of obesity, daytime hypoventilation, and sleep-disordered breathing in the absence of an alternative neuromuscular, mechanical or metabolic explanation for hypoventilation. During the last 3 decades the prevalence of extreme obesity has markedly increased in the United States and other countries. With such a global epidemic of obesity, the prevalence of OHS is bound to increase. Patients with OHS have a lower quality of life, with increased healthcare expenses, and are at higher risk of developing pulmonary hypertension and early mortality, compared to eucapnic patients with sleep-disordered breathing. OHS often remains undiagnosed until late in the course of the disease. Early recognition is important, as these patients have significant morbidity and mortality. Effective treatment can lead to significant improvement in patient outcomes, underscoring the importance of early diagnosis. This review will include disease definition and epidemiology, clinical characteristics of the syndrome, pathophysiology, and morbidity and mortality associated with it. Lastly, treatment modalities will be discussed in detail.
More PubMed results on OHS.