This may take 24 to 48 hours for it to take effect, and it is not well suited to cases where the impaction needs to be removed immediately due to risk of complications or severe pain. Enemas (such as hyperosmotic saline) and suppositories (such as glycerine suppositories) work by increasing water content and stimulating peristalsis to aid in expulsion, and both work much more quickly than oral laxatives. Because enemas work in 2–15 minutes, they do not allow sufficient time for a large fecal mass to soften. Even if the enema is successful at dislodging the impacted stool, the impacted stool may remain too large to be expelled through the anal canal. Mineral oil enemas can assist by lubricating the stool for easier passage. In cases where enemas fail to remove the impaction, polyethylene glycol can be used to attempt to soften the mass over 24–48 hours, or if immediate removal of the mass is needed, manual disimpaction may be used. Manual disimpaction may be performed by lubricating the anus and using one gloved finger with a scoop-like motion to break up the fecal mass. Most often manual disimpaction is performed without general anaesthesia, although sedation may be used. In more involved procedures, general anaesthesia may be used, although the use of general anaesthesia increases the risk of damage to the anal sphincter. If all other treatments fail, surgery may be necessary. An easier, more comfortable, and more efficient method to enema and manual disimpaction is to use pulsed irrigation evacuation (PIE).
Pneumothorax ex vacuo is a rare type of pneumothorax which forms adjacent to an atelectatic lobe. It is seen preferentially with atelectasis of the right upper lobe and is the result of rapid atelectasis producing an abrupt decrease in the intrapleural pressure with subsequent release of nitrogen from pleural capillaries. Treatment
Treatment consists of bronchoscopy rather than chest tube drainage. Radiographically, pneumothorax ex vacuo is suggested when an atelectatic lobe or lung, particularly right upper lobe atelectasis, is surrounded by a focal pneumothorax. Related illness
"Trapped lung" presents in the same way as pneumothorax ex vacuo and can occur in patients with visceral pleural thickening and following drainage of an effusion. == References ==