Do your NIV patients ever experience fogging or condensation in their masks? In combination with a high respiratory rate (RR) and elevated PaCO₂, it may indicate that the patient is rebreathing their own CO2 as the flow inside the mask is insufficient to effectively clear out heat, humidity, and, most importantly, carbon dioxide (CO₂).

Unfortunately, traditional single-port masks allow for the rebreathing of CO₂. Inhaling elevated levels of CO₂ during Non-Invasive Ventilation (NIV), a condition known as hypercapnia, can be harmful as it causes carbon dioxide to accumulate in the blood, leading to respiratory acidosis and potentially severe complications.¹

A 2022 study examined whether a new NIV mask design (dual-port) could reduce carbon dioxide rebreathing. The study took healthy adult volunteers and compared the dual-limb mask to the traditional single-port mask. In the first phase, CO₂ levels were measured during different modes of ventilation, while in the second phase, prolonged use was studied to assess breathing patterns using electrical impedance tomography.²

The results showed that the dual-port mask significantly reduced inspired CO₂ levels across all tested scenarios, with the most pronounced effect seen during continuous-flow CPAP, as shown in Fig. 1.

Fig. 1. End-inspiratory CO 2 difference between one-limb and two-limb masks for different ventilation settings on 10 healthy volunteers recorded during phase 1: (a) continuous-flow CPAP 60 L/min; (b) continuous-flow CPAP 90 L/min; (c) demand-flow CPAP 8 L/min; (d) demand-flow CPAP 20 L/min; (e) PSV (PS 5 cm H 2O) with bias flow 8 L/min; (f) PSV (PS 5 cmH2O) with bias flow 20 L/min. CPAP, continuous positive airway pressure; PEEP, positive end-expiratory pressure; PS, pressure support; PSV, pressure support ventilation

The DiMax ZERO Total-Face Mask offers a forward-thinking solution to reduce CO₂ rebreathing with its unique design that features separate inspiratory and expiratory connections. This single patient-use mask supports PSV, BiLevel-BIPAP, and CPAP ventilation modes. The five-point headgear ensures the mask stays in place, optimizes patient/ventilator synchronization, and reduces leakage. The mask’s lightweight, flexible polycarbonate construction, paired with a 0.3 mil silicone membrane, allows it to fit a wide range of face shapes and sizes comfortably, preventing skin injuries.

• Separate inspiratory/expiratory ports minimize CO₂ rebreathing
• Compatible with multiple ventilation modes (PSV, BiLevel-BIPAP, CPAP)
• Includes adapters for a wide range of setups and procedures
• Comfortable, secure fit with five-point headgear
• Available in sizes: Small to XXL