Permissive Hypercapnia in Heart Failure Patients

Introduction to Permissive Hypercapnia

Permissive hypercapnia is acceptable in heart failure patients when implementing reduced tidal volume ventilation strategies, particularly in those with high inspiratory pressures or at risk for barotrauma/volutrauma 1

The European Society of Cardiology recommends permissive hypercapnia through reduced tidal volume ventilation in mechanically ventilated patients with high inspiratory pressures or at risk for barotrauma/volutrauma 1
The upper limit for PaCO2 has not been definitively established, but arterial pH should be maintained above 7.20 1, 2
Normalization of arterial blood gas values is not considered a valuable therapeutic maneuver in these patients 1

Non-invasive positive pressure ventilation (CPAP, BiPAP) should be considered in patients with respiratory distress (respiratory rate >25 breaths/min, SpO2 <90%) 3, 4
The European Heart Society recommends NIV to improve clinical parameters including respiratory distress and to reduce the need for intubation 3, 5
Intubation is recommended only if respiratory failure leading to hypoxemia (PaO2 <60 mmHg), hypercapnia (PaCO2 >50 mmHg), and acidosis (pH <7.35) cannot be managed non-invasively 3, 4

Monitor transcutaneous arterial oxygen saturation (SpO2) continuously 3, 4
Consider measurement of blood pH and carbon dioxide tension, especially in patients with acute pulmonary edema or previous history of COPD 3
Maintain arterial pH above 7.20 while allowing PaCO2 to rise 1, 2
Monitor blood pressure regularly, as NIV can reduce blood pressure and should be used with caution in hypotensive patients 3, 4

Use permissive hypercapnia with caution in patients with cardiogenic shock and right ventricular failure 5, 6
Be aware that hypercapnia may cause cerebral vasodilation and a rise in intracranial pressure, and may compromise myocardial contractility 2
In patients with COPD or other risk factors for hypercapnic respiratory failure, aim for a saturation of 88-92% pending blood gas results 7
Avoid routine use of oxygen in non-hypoxemic heart failure patients, as it causes vasoconstriction and reduces cardiac output 3, 8