From the Guidelines
Bilateral posterior lung infiltrates after CPR and ventricular fibrillation arrest should be managed with a focus on avoiding hyperventilation and maintaining normocapnia, as well as providing respiratory support with supplemental oxygen therapy and potentially escalating to non-invasive ventilation (CPAP/BiPAP) or mechanical ventilation if respiratory failure develops. The treatment approach should prioritize maintaining an arterial oxyhemoglobin saturation of 94% and avoiding hyperoxia, as recommended by the 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1.
Key considerations in the management of these patients include:
- Avoiding hyperventilation, which can cause cerebral vasoconstriction and worsen global brain ischemia 1
- Maintaining normocapnia, with a goal of keeping Pa CO2 between 40-45 mm Hg or P ETCO2 between 35-40 mm Hg 1
- Providing protective lung ventilation strategies, including tidal volumes of 6-8 ml/kg ideal body weight and positive end-expiratory pressure (PEEP) of 4-8 cm H2O 1
- Using diuretics like furosemide 20-40mg IV to reduce pulmonary edema, and empiric antibiotics such as ceftriaxone 1-2g IV daily plus azithromycin 500mg daily if aspiration pneumonia is suspected, pending culture results
- Maintaining euvolemia, optimizing cardiac function with appropriate medications based on cardiac evaluation, and continuing post-arrest care including targeted temperature management if indicated
Regular chest X-rays and arterial blood gas monitoring are essential to track improvement, and the infiltrates typically result from increased capillary permeability due to ischemia-reperfusion injury during cardiac arrest and CPR, or from gastric contents aspiration during the arrest 1. Recovery time varies from days to weeks depending on severity and underlying conditions, with most patients showing radiographic improvement within 5-7 days with appropriate treatment.
From the Research
Bilateral Posterior Lung Infiltrates after CPR and V Fib Arrest Treatment
- Bilateral posterior lung infiltrates can occur after cardiopulmonary resuscitation (CPR) and ventricular fibrillation (V Fib) arrest treatment due to various factors, including aspiration, pulmonary contusions, and systemic inflammation 2.
- The development of acute respiratory distress syndrome (ARDS) is a potential complication in patients who experience cardiac arrest, with risk factors including aspiration, pulmonary contusions, systemic inflammation, and reperfusion injury 2.
- Mechanical ventilation strategies, such as lung-protective ventilation with low tidal volumes, may be beneficial in improving outcomes after cardiac arrest 2, 3.
- The use of positive end-expiratory pressure (PEEP) and lower tidal volumes can help improve oxygenation and reduce lung injury in patients with ARDS 3, 4.
- The PaO2/FiO2 ratio is a useful indicator of lung injury severity and can be used to guide mechanical ventilation strategies 4.
Mechanical Ventilation Strategies
- Different mechanical ventilation strategies, such as lower tidal volume and higher PEEP, can have varying effects on oxygenation, pulmonary compliance, and length of ICU stay 3.
- A strategy of lower tidal volume and higher PEEP may result in improved oxygenation, while a strategy of higher tidal volume and lower PEEP may improve pulmonary compliance 3.
- The choice of mechanical ventilation strategy should be individualized based on the patient's specific needs and lung function 3, 5.
Lung Injury Severity Scoring
- Lung injury severity scoring systems, such as the Murray lung injury score, may be limited by their dependence on therapy-dependent criteria 4.
- The PaO2/FiO2 ratio is a simple and accurate method for quantifying lung injury severity and predicting mortality 4.
- The use of lung-protective mechanical ventilation strategies can help minimize ventilator-induced lung injury and improve outcomes in patients with acute lung injury or ARDS 6.