Diagnosis and Management of Obesity Hypoventilation Syndrome in the ICU
Section snippets
Historical perspective and definition
In 1955, Auchincloss and colleagues [1] described in detail the first case of a patient who had obesity hypoventilation syndrome (OHS). The following year, Burwell and colleagues [2] compared patients who had OHS to an obese, somnolent Charles Dickens' character and popularized the description “Pickwickian syndrome.” The central features of OHS include obesity (body mass index [BMI] ≥ 30 kg/m2), chronic alveolar hypoventilation leading to daytime hypercapnia (Paco2 ≥ 45 mm Hg), and
Morbidity and mortality
OHS is often unrecognized and treatment is frequently delayed, and can cause secondary erythrocytosis, pulmonary hypertension, and cor pulmonale. The delay in recognizing and treating this condition increases health care resource use and the likelihood of requiring hospitalization compared with patients who have similar degrees of obesity [7]. The most common reasons for hospitalizations are dyspnea and acute-on-chronic hypercapnic respiratory failure. Once hospitalized, patients who have OHS
Pathophysiology
The mechanism by which morbid obesity leads to hypoventilation is complex and not fully understood. Proposed mechanisms include abnormal respiratory system mechanics because of obesity, impaired central responses to hypercapnia and hypoxia, sleep-disordered breathing, and neurohormonal abnormalities, such as leptin resistance (Box 3) [4], [15].
Obesity imposes a significant mechanical load leading to a reduction in total respiratory system compliance, increased lung resistance, and a relative
Epidemiology
Because of the global obesity epidemic and the high prevalence of OSA in the general population, critical care physicians are likely to encounter patients who have acute-on-chronic respiratory failure attributable to OHS in their clinical practice. The prevalence of OHS amongst patients who have OSA has been estimated between 10% and 20% and is higher in the subgroup of patients who have extreme obesity (Fig. 1) [20], [21]. The prevalence of OHS is even higher (31%) in obese patients admitted
Clinical presentation
OHS is slightly more prevalent in men and most patients are diagnosed in their fifth or sixth decade of life. The vast majority of patients have the classic symptoms of OSA, including loud snoring, nocturnal choking episodes with witnessed apneas, excessive daytime sleepiness, and morning headaches. In contrast to eucapnic OSA, patients who have stable OHS frequently complain of dyspnea and may have signs of cor pulmonale. With acute-on-chronic hypercapnic respiratory failure, patients who have
Therapeutic options
In an ICU setting there are several therapeutic modalities that can improve ventilation and oxygenation in patients who have OHS who are experiencing an acute-on-chronic hypercapnic respiratory failure: NPPV, endotracheal intubation with invasive mechanical ventilation, and tracheostomy with or without mechanical ventilation. Although most of these patients need supplemental oxygen therapy in addition to positive airway pressure therapy, supplemental oxygen alone is inadequate and does not
Noninvasive positive pressure ventilation
Contrary to eucapnic OSA, effective treatment strategies for OHS must relieve upper airway obstruction and increase alveolar ventilation. The therapy of choice for the acutely decompensated patient who has OHS with hypercapnic respiratory failure is NPPV. NPPV can be applied with volume-limited, or more commonly, pressure-limited devices (eg, bilevel positive airway pressure [bilevel PAP] or pressure support ventilation). Although these two modes of NPPV have not been compared in patients who
Tracheostomy
Tracheostomy should be reserved for patients who have refractory OHS who have failed other modes of ventilatory support, are intolerant of NPPV, have severe cor pulmonale, or have a longstanding history of nonadherence with outpatient NPPV therapy. Tracheostomy may also become necessary in a subset of patients who cannot be successfully extubated and liberated from invasive mechanical ventilation. Tracheostomy bypasses the crowded upper airway and can substantially decrease apneas and hypopneas
Discusssion
Because of the global obesity epidemic and the high prevalence of OSA in the general population, critical care physicians are likely to encounter patients who have acute-on-chronic hypercapnic respiratory failure attributable to OHS in their clinical practice. We believe that early recognition of OHS leads to effective treatment and likely results in a decrease in morbidity and mortality. In the ICU setting, implementation of NPPV has marked beneficial effects leading to improvement in alveolar
Summary
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OHS is characterized by obesity (BMI ≥ 30 kg/m2), daytime hypercapnia (Paco2 ≥ 45 mm Hg), and sleep-disordered breathing in the absence of other known causes of hypercapnia.
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Patients who have OHS have increased health care resources use and require more frequent hospitalization because of dyspnea or acute-on-chronic hypercapnic respiratory failure compared with patients who have similar degrees of obesity.
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The pathophysiology of OHS is multifactorial and includes abnormal respiratory system
References (61)
- et al.
Recent advances in obesity hypoventilation syndrome
Chest
(2007) - et al.
The obesity-hypoventilation syndrome revisited: a prospective study of 34 consecutive cases
Chest
(2001) - et al.
The use of health-care resources in obesity-hypoventilation syndrome
Chest
(2001) - et al.
Obesity-associated hypoventilation in hospitalized patients: prevalence, effects, and outcome
Am J Med
(2004) - et al.
In-hospital mortality in the Pickwickian syndrome
Am J Med
(1974) - et al.
Evolution of patients with chronic obstructive pulmonary disease, obesity hypoventilation syndrome or congestive heart failure in a respiratory monitoring unit
Arch Bronconeumol
(2006) - et al.
Non-invasive positive pressure ventilation improves lung volumes in the obesity hypoventilation syndrome
Respir Med
(2007) - et al.
The obesity hypoventilation syndrome
Am J Med
(2005) - et al.
Neuromechanical properties in obese patients during carbon dioxide rebreathing
Am J Med
(1983) Pulmonary complications of obesity
Am J Med Sci
(2001)
Daytime hypercapnia in adult patients with obstructive sleep apnea syndrome in France, before initiating nocturnal nasal continuous positive airway pressure therapy
Chest
Hypercapnia in the obstructive sleep apnea syndrome. A reevaluation of the “Pickwickian syndrome”
Chest
Treatment effects on carbon dioxide retention in patients with obstructive sleep apnea-hypopnea syndrome
Chest
Nasal CPAP continues to improve sleep-disordered breathing and daytime oxygenation over long-term follow-up of occlusive sleep apnea syndrome
Chest
Obesity hypoventilation syndrome as a spectrum of respiratory disturbances during sleep
Chest
The obesity hypoventilation syndrome can be treated with noninvasive mechanical ventilation
Chest
Benefits at 1 year of nocturnal intermittent positive pressure ventilation in patients with obesity-hypoventilation syndrome
Respir Med
Noninvasive positive pressure ventilation and not oxygen may prevent overt ventilatory failure in patients with chest wall diseases
Chest
Obesity hypoventilation syndrome: hypoxemia during continuous positive airway pressure
Chest
Positive airway pressure titration in obesity hypoventilation syndrome: continuous positive airway pressure or bilevel positive airway pressure
Chest
Non-invasive positive pressure ventilation improves lung volumes in the obesity hypoventilation syndrome
Respir Med
Comparison of volume- and pressure-limited NPPV at night: a prospective randomized cross-over trial
Respir Med
Nocturnal nasal intermittent positive pressure ventilation with bi-level positive airway pressure (BiPAP) in respiratory failure
Chest
Long-term cardiovascular outcomes in men with obstructive sleep apnoea-hypopnoea with or without treatment with continuous positive airway pressure: an observational study
Lancet
Mortality in obstructive sleep apnea-hypopnea patients treated with positive airway pressure
Chest
The use of noninvasive ventilation in acute respiratory failure at a tertiary care center
Chest
Early use of non-invasive ventilation for acute exacerbations of chronic obstructive pulmonary disease on general respiratory wards: a multicentre randomised controlled trial
Lancet
Human and financial costs of noninvasive mechanical ventilation in patients affected by COPD and acute respiratory failure
Chest
Predicting the result of noninvasive ventilation in severe acute exacerbations of patients with chronic airflow limitation
Chest
Airway management in critical illness
Chest
Cited by (37)
Clinical Assessment of the Patient With Respiratory Sleep Disorder
2021, Encyclopedia of Respiratory Medicine, Second EditionExtubating to Noninvasive Ventilation: Noninvasive Ventilation from Intensive Care Unit to Home
2020, Sleep Medicine ClinicsCitation Excerpt :In an ambulatory setting, serum bicarbonate, Paco2, pulse oximetry, and nocturnal capnometry can be used as tools to screen for OHS, but in the hospital setting, one can only suspect OHS based on BMI and presence of hypercapnic respiratory failure. Several ventilator modalities are available for management of patients with suspected OHS with acute or chronic hypercapnic respiratory failure in the ICU—these include NIV, endotracheal intubation with mechanical ventilation, and trach ± mechanical ventilation.32 Inpatient CPAP is only recommended for those patients with stable OHS, but oftentimes, patients with OHS in the ICU are battling acute on chronic hypercapnic respiratory failure, and CPAP is therefore not the modality of choice owing to its lack of ability to optimally ventilate these hypercapnic patients.
Effectiveness of different treatments in obesity hypoventilation syndrome
2020, PulmonologyCitation Excerpt :PAP therapy improves gas exchange, respiratory sleep disorders and probably lung function and central respiratory impulse to carbon dioxide (CO2). Night-time hypoventilation can be effectively improved, but not in all cases,46–49 and daytime PaCO2 reduced or restored to normal values.48 The effectiveness of NIV has been assessed in several long-term, observational studies1,7,23,44,50–55 and medium-term randomised trials.3,21,56
Obesity hypoventilation in the intensive care unit
2020, Obesity Hypoventilation Syndrome: From Physiologic Principles to Clinical PracticeSocial and Economic Impacts of Managing Sleep Hypoventilation Syndromes
2017, Sleep Medicine ClinicsCitation Excerpt :More information regarding differences in presentation and treatment of these populations is needed. Patients with OHS often go unnoticed until they present in acute respiratory failure.1,38 In one study, nearly a third of hospitalized obese (BMI ≥35 kg/m2) patients, most of whom were previously undiagnosed, had OHS.1
Nocturnal Ventilation in Chronic Hypercapnic Respiratory Diseases
2012, Therapy in Sleep Medicine