<prompt> The indication for using Heimlich valve is for drainage of:PneumothoraxHemothoraxEmpyemaMalignant pleural effusion  <response>: Most patients with significant pneumothoraces 30 require placement of a closed-chest catheter 8-20F for acceptable reexpansion. This catheter then can be placed either to underwater suction drainage or to a Heimlich one-way valve. If a Heimlich valve maintains full expansion, the patient may be treated as an outpatient; however, if a Heimlich valve fails to reexpand the lung fully or if the patients condition is not optimal, admission to hospital and underwater chest tube suction drainage is required. Ref: Theodore P.R., Jablons D. 2010. Chapter 18. Thoracic Wall, Pleura, Mediastinum, Lung. In G.M. Dohey Ed, CURRENT Diagnosis Treatment: Surgery, 13e. 