Which of the following complications is associated with mechanical ventilation? Select all that apply

A. Critically ill clients on mechanical ventilation are at increased risk of stress-related mucosal damage, which can lead to gastric or duodenal ulcers due to physiologic stress, reduced perfusion, and acid hypersecretion. B. Mechanical ventilation does not directly suppress the immune system. Immunosuppression may occur due to underlying illness, medications, or critical illness, but it is not a direct complication of the ventilator itself. C. Positive pressure ventilation can increase intrathoracic pressure, reducing venous return to the heart, which may lead to decreased cardiac output and hypotension, especially in patients with hypovolemia. D. Mechanical ventilation does not directly cause pulmonary emboli. Risk factors for emboli include immobility, hypercoagulable states, or recent surgery, not the ventilator itself. E. Mechanical ventilation can cause barotrauma, which is damage to the alveoli or lungs due to excessive pressure or volume, potentially leading to pneumothorax, subcutaneous emphysema, or pneumomediastinum. F. Mechanical ventilation increases the risk of ventilator-associated pneumonia (VAP) due to impaired airway defense, colonization of the endotracheal tube, and aspiration of secretions.