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Management of Obesity Hypoventilation Guidelines: 2019

New guidelines have been released for OHS management. OHS is defined by the combination of obesity (BMI > 30 kg/m2), sleep disordered breathing (SDB), and awake daytime hypercapnia (awake resting PaCO2 > 45 mm Hg), after excluding other causes for hypoventilation. It can lead to serious sequelae, including increased rates of mortality and hospitalization due to acute-on-chronic hypercapnic respiratory failure, among others. The purpose of this guideline is to attempt to standardize as well as optimize the evaluation and management of patients with OHS. The multi-disciplinary panel prioritized five clinical questions, with suggested recommendations after reviewing the overall low quality of evidence. Below includes a summary of the salient points of these recommendations:

  • Should we use serum bicarbonate and/or oxygen saturation via pulse oximetry over arterial PaCO2 to screen for OHS in obese adults with SDB
    • For low to moderate clinical suspicion for OHS – clinicians may use a serum bicarbonate level of <27 mmol/L to exclude the diagnosis of OHS in obese patients with SDB (if >27 mmol/L, measure an arterial blood gas).
    • For a high clinical suspicion for OHS: Measure arterial blood gas.
    • There is insufficient data for the clinical usefulness of awake SpO2 for screening for OHS in obese patients with OSA.
  • Should OHS be treated with positive airway pressure (PAP, either continuous positive airway pressure [CPAP] or non-invasive ventilation [NIV]) or not be treated with PAP?
    • Stable ambulatory patients with OHS should receive PAP.
  • Use of CPAP vs NIV for the treatment of adults with OHS
    • In OHS coexisting with severe OSA (apnea-hypopnea index > 30 events/h), use CPAP as first-line rather than NIV (Notably, more than 70% of patients with OHS also have severe OSA).
  • Should hospitalized adults suspected of having OHS, be discharged with or without PAP treatment until the diagnosis of OHS is either confirmed or ruled out?
    • Patients hospitalized with respiratory failure and suspected of having OHS should be discharged with NIV until they undergo outpatient diagnostic procedures and PAP titration in the sleep laboratory. (Discharging patients with NIV should not be a substitute for arranging outpatient diagnostics.)
  • Should weight-loss be used as an intervention for adults with OHS?
    • Patients with OHS should use weight-loss interventions that produce sustained weight loss of 25% to 30% of body weight to achieve resolution of OHS (more likely to be obtained with bariatric surgery).

It is important to note that one should not apply the recommendations from these guidelines in a blanket fashion without an understanding of the individual patient, as no recommendation can take into account all of the variables that come into play with each individual patient. Additionally, these recommendations should not be used as an argument against additional research and will likely change once additional data are available.