What are the Non-Invasive Ventilation (NIV) settings for a 60-year-old obese patient with bilateral pneumonia and hypercapnia (elevated partial pressure of carbon dioxide, PaCO2)?

From the Guidelines

For a 60-year-old obese patient with bilateral pneumonia and hypercapnia, I recommend starting non-invasive ventilation (NIV) with an EPAP in the 10-15 range and an IPAP of >30, if necessary, to effectively manage upper airway obstruction and ensure adequate tidal volume. The patient's obesity and severe hypercapnia increase the risk of sudden deterioration and difficulty with intubation, making expert assessment crucial for titrating EPAP and IPAP settings 1. Key considerations for NIV settings include:

• EPAP: 10-15 cmH2O to address upper airway obstruction, which is common in obese patients and may persist despite increasing EPAP
• IPAP: >30 cmH2O may be required to ensure adequate tidal volume, as impedance to inflation can be very high in some patients
• I:E ratio: 1:1 to increase the resulting tidal volume delivered
• Mode: Consider using volume-controlled ventilation or a volume-assured mode if the resulting tidal volume is still inadequate It is essential to closely monitor the patient's response to NIV, including arterial blood gases, and adjust settings accordingly to prevent NIV failure and ensure optimal management of hypercapnia and oxygenation 1.

From the Research

Non-Invasive Ventilation (NIV) Settings for Obese Patients with Bilateral Pneumonia and Hypercapnia

• The optimal NIV strategy for a 60-year-old obese patient with bilateral pneumonia and hypercapnia is not explicitly stated in the provided studies, but some general guidelines can be inferred from the available evidence 2, 3, 4, 5, 6.
• For acute hypercapnic respiratory failure, NIV can be delivered using continuous positive airway pressure (CPAP) or pressure support ventilation (NIPSV), also known as bilevel positive airway pressure (BIPAP) 2.
• The initial setting for NIPSV typically includes an expiratory pressure (EPAP or PEEP) of 5 cmH2O and an inspiratory pressure between 12 and 25 cmH2O, although the level of pressure support may be lower initially 2.
• Obese patients may require higher end-expiratory pressure levels and more time to reduce their PaCO2 levels below 50 mmHg than non-obese patients 3.
• Non-invasive strategies should first optimize body position with reverse Trendelenburg position or sitting position, and positive pressure pre-oxygenation before intubation procedure is recommended 4.
• The use of facial masks, high FiO2, and sedation with opiates are complementary maneuvers that may be recommended in this context in the majority of patients 2.

Considerations for Obese Patients

• Obesity is an important risk factor for major complications, morbidity, and mortality related to intubation procedures and ventilation in the ICU 4.
• The fall in functional residual capacity promotes airway closure and atelectasis formation in obese patients 4.
• Non-invasive ventilation (NIV) is considered as the first-line therapy in patients with obesity having postoperative acute respiratory failure 4.
• Prophylactic NIV should be considered after extubation to prevent re-intubation 4.

NIV Modalities

• CPAP is a simple technique that may reduce preload and afterload, increasing cardiac output in some patients, and is typically set at 10 cmH2O 2.
• NIPSV is a more complex mode that requires a ventilator and experience, and is usually applied with an expiratory pressure (EPAP or PEEP) resulting in a bilevel pressure modality (BIPAP) 2.
• Both CPAP and NIV appear safe and effective in patients with obesity-related respiratory failure and OSA, with or without COPD 6.