Negative pressure ventilation is not new. Indeed the first practical ventilator for human subjects was the iron lung designed in the late 1920s to provide ventilatory assistance to patients with poliomyelitis.¹ However, negative pressure ventilation has been largely superseded by developments of positive pressure ventilation equipment and techniques, including non-invasive positive pressure ventilation. In this issue of the journal, Al-balkhi and colleagues suggest a role for negative pressure ventilation in the treatment of infants with apnoea associated with bronchiolitis.² So is negative pressure ventilation on the brink of a comeback or should it be properly consigned to history?

Negative pressure ventilation (NPV) relies on the application of a subatmospheric pressure to the thorax, which is transmitted to a reduction of intrapleural pressure, leading to expansion of the lungs. By cycling the pressure and allowing passive deflation of the lungs as the negative intrapleural pressure rises, alveolar ventilation can occur. Advantages of negative pressure ventilation include avoidance of the adverse effects of endotracheal intubation and positive pressure ventilation. The patient’s airway may be accessed readily during NPV for diagnostic or therapeutic procedures such as suctioning of secretions or fibreoptic bronchoscopy. There is also a beneficial effect on cardiac output, probably related to increased systemic venous return, although this effect may only apply when negative pressure is applied to the thorax alone using a cuirass or wrap rather than to the entire body surface as occurs with …