From the Guidelines
A CPAP order is appropriate for this patient with sleep apnea experiencing significant desaturations despite being on a venti mask, and I recommend starting with CPAP at 5-10 cmH2O pressure and titrating based on oxygen saturation response, aiming to maintain SpO2 >90%. The patient's presentation with septic shock, pneumonia, and acute hypoxemic respiratory failure, combined with underlying sleep apnea, indicates a need for positive pressure support. CPAP therapy would help maintain airway patency, prevent alveolar collapse, improve oxygenation, and reduce work of breathing 1. According to the study by Thorax in 2002, CPAP is employed in patients with acute respiratory failure to correct hypoxaemia, and it permits a higher inspired oxygen content than other methods of oxygen supplementation 1.
The study from the Journal of Clinical Sleep Medicine in 2010 provides guidelines for the adjustment of noninvasive positive pressure ventilation (NPPV) in stable chronic alveolar hypoventilation syndromes, which includes recommendations for increasing IPAP and/or EPAP to eliminate obstructive respiratory events, and increasing pressure support (PS) if the arterial PCO2 remains elevated or if respiratory muscle rest has not been achieved 1. However, in this acute setting, the primary goal is to improve oxygenation and reduce work of breathing.
Close monitoring is essential, including continuous pulse oximetry and frequent vital sign checks. If the patient fails to improve with CPAP or shows signs of increasing respiratory distress, escalation to BiPAP or intubation may be necessary. The underlying septic shock and pneumonia should be treated concurrently with appropriate antibiotics and hemodynamic support. It is crucial to prioritize the patient's morbidity, mortality, and quality of life, and CPAP therapy is a crucial step in achieving this goal.
From the Research
Patient Management
- The patient is experiencing septic shock, pneumonia (PNA), and acute hypoxemic respiratory failure (AHRF), with a history of sleep apnea and desaturation to the 80s despite being on a venti mask 2, 3, 4.
- The use of non-invasive ventilation, such as CPAP, may be considered for patients with acute hypoxemic respiratory failure, including those with sepsis or septic shock 5.
- However, the decision to intubate and mechanically ventilate a patient should be based on individual clinical judgment, taking into account factors such as the severity of respiratory failure, the patient's overall condition, and the potential risks and benefits of intubation 3, 4.
Ventilation Strategies
- Low tidal volume ventilation is recommended for patients with acute respiratory distress syndrome (ARDS) 4.
- Lung-protective ventilation strategies may also be beneficial for non-ARDS patients, although the evidence is less conclusive 4.
- Non-invasive respiratory support modalities, such as CPAP, may be used to reduce the need for intubation in patients with acute hypoxemic respiratory failure 5.
Clinical Management
- The Surviving Sepsis Campaign recommends the use of norepinephrine as the first-line inotropic support for patients with severe sepsis or septic shock 6.
- Clinical management of patients with severe sepsis or septic shock should include careful monitoring of fluid resuscitation, mechanical ventilation, and vasopressor support, as well as consideration of the patient's overall condition and potential complications 6.