Table 2 Modalities, settings, advantages, limits and indications of the different respiratory supports used in cardiogenic shock

O2 mask

Oxygen flow: adjust with objective of SaO₂ 92–98%

Avoid hypoxia

Simple and accessible device

No PEEP effect

Limited oxygen flow at 15 L/min

First-line support until NIV or IMV in case of respiratory failure

Acute cardiogenic pulmonary edema: compared to oxygenotherapy, PEEP induced a faster improvement of respiratory distress and acidosis without significant difference in mortality or intubation within 7 days [109]

No data regarding CS specifically

Non invasive ventilation (NIV)

 Continuous positive airway pressure (CPAP)

 Bilevel positive air pressure (BIPAP)

Positive Pressure ventilation (PPV) with positive end expiratory pressure (PEEP): minimal starting setting at 5–10 cmH₂O, adjust according to SaO₂

In case of BIPAP, adjust inspiratory positive airway pressure according to respiratory rate

FiO2: adjust with objective of SaO₂ 92–98% [106]

Need correct selection of interfaces, favorable patient/ventilator synchrony, comfort and active participation of the patient

1. Respiratory effects:

 Reduced alveolo-interstitial edema

 Induced alveolar recruitment

 Improve oxygenation: reversion of hypoxic pulmonary vasoconstriction, better systemic and myocardial oxygenation

 Improve decarboxylation

 Decreasing work-of-breathing and reduce the oxygen consumption of the diaphragm

2. Hemodynamic effects

 Reduce RV/LV preload and LV afterload

 Improve cardiac output

Could reduce the risk of invasive mechanical ventilation [111,112,113]

Simple and accessible device

Absolute contraindications:

 Severely impaired consciousness

 Refractory vomiting

 Facial trauma

 Hemodynamic instability

Relative contraindications:

 Inability to cough

 Uncooperative patient

NIV compared to IMV in a non-randomized study: no difference of mortality [115]

First line: respiratory distress in heart failure patients, without absolute contraindications to NIV [5, 34, 35, 106]

Second line: should be considered in CS only after:

 Hemodynamic stabilization

 An assessment of the risk–benefit balance

 Without absolute contraindications to NIV

 With a close monitoring of efficacity

Device: BIPAP increase Vt and could be preferable compared to CPAP in case of hypercapnia, chronic lung disease or severe RF

Invasive mechanical ventilation (IMV)

FiO2: adjust with objective of SaO₂ 92–98% [106]

PEEP: set at 5 cmH₂O, gradually increased according to respiratory (overdistension, barotrauma) and hemodynamic (decrease RV preload and increase RV afterload) risks of excessive PEEP

Respiratory rate: adjust to limit hypercapnia acidosis (worsening of RV dysfunction risk)

Vt: should not exceed 6–8 mL/kg of ideal body weight

No data and recommendations regarding superiority of any specific mode (volume or pressure control) [5, 34, 35, 106]

1. Respiratory effects:

 Reduced alveolo-interstitial edema

 Induced alveolar recruitment

 Improve oxygenation: reversion of hypoxic pulmonary vasoconstriction, better systemic and myocardial oxygenation

 Improve decarboxylation

 Decreasing work-of-breathing and reduce the oxygen consumption of the diaphragm

2. Hemodynamic effects:

 Reduce RV/LV preload and LV afterload

 Improve cardiac output

Sedation use: could reduce oxygen consumption and improve cardiac output

Risks associated with anaesthesia induction and intubation: hypotension, hypoxia, transient low cardiac output due to intrathoracic pressures change, cardiac arrest

Specific mode: pressure supported ventilation (PSV) could increase myocardial oxygen consumption if spontaneous breath is no fully supported [122]

First line: [5, 34, 35, 106]

 Refractory shock with severe hypotension

 Need for effective airway protection due to coma/impairment of consciousness

 Refractory vomiting

 Facial trauma

Second line after NIV failure [5, 34, 35, 106]

High flow nasal canula (HFNC)

FiO2: adjust with objective of SaO₂ 92–98%

High oxygen flow (max 60L/min, FIO2 1)

Improvement of oxygenation

Simple and accessible device

Inconstant PEEP “effect”, between 5 and 7 cmH₂O

Scarce data

Remains actually unclear [119, 120]