ingested should be identified, as this information may be useful in guiding further management Clinicians should contact their regional Poison Control Center; this is often very helpful in determining active ingredients and the degree of concern for a given substance (see Chapter 102 Toxicologic Emergencies ) The airway should be assessed and secured if necessary Stridor should raise concern for laryngeal edema and orotracheal intubation is indicated in its presence The airway should be visualized during this maneuver and tubes should not be passed blindly One exception to this is in the case of ingested hydrofluoric acid, which requires immediate evacuation, best achieved by nasogastric decompression of the stomach Patients presenting to the ED following a caustic ingestion may become critically ill and should be closely monitored with this in mind They should remain nil per os and large-bore intravenous lines should be placed for fluid administration Measures to dilute or neutralize the ingested agent may cause further complications, and activated charcoal and emetic agents should be avoided Two view radiographs of the chest and abdomen should be performed and reviewed carefully for evidence of pneumomediastinum, pneumoperitoneum, and pleural effusion These findings raise concern for full-thickness esophageal or gastric injury Patients with suspected esophageal or gastric injury should receive prompt gastroenterology and/or surgical evaluation, as early endoscopy is the gold standard for the assessment of caustic injuries and should be performed within the first 12 to 24 hours after ingestion Patients with any concerning history or findings should be admitted to the appropriate inpatient ward for close monitoring thereafter, and patients with obvious perforation should receive broad-spectrum antibiotics and will likely require urgent operative management PLEURAL DISEASES The lung is covered by the densely adherent visceral pleura, which moves smoothly over the parietal pleura of the chest wall A thin fluid film and the friction created by apposition of the pleural layers (like two plates of glass held together by a film of water) contribute to the full expansion of the lung mechanically When air, excess fluid, or purulent material comes between the two layers of the pleura, the lung may collapse or become significantly compressed and consideration needs to be given to drainage of the pleural space Pneumothorax PEARLS AND PITFALLS Tension pneumothorax is a clinical diagnosis and does not require a radiograph for confirmation if there is hemodynamic compromise Exercise caution in sedating patients with pneumothoraces or converting them to positive pressure ventilation since their hemodynamic status can be tenuous Children with even small pneumothoraces may require admission for observation Current Evidence A pneumothorax is a collection of air in the pleural space It can occur for shortor long-term duration and can be static or accumulate progressively Because atmospheric pressure is greater than intrapleural pressure, any mechanism that allows even momentary communication between the atmosphere outside the chest wall or within the tracheobronchial tree can result in a rapid shift of air into the pleural space A pneumothorax may occur spontaneously, or it may be the result of trauma or a therapeutic intervention Children with no known predisposing pulmonary conditions are diagnosed as having a primary spontaneous pneumothorax Secondary spontaneous pneumothoraces occur in patients with underlying diseases such as asthma, cystic fibrosis, or structural abnormalities such as congenital blebs, pneumatoceles, or congenital pulmonary airway malformations (CPAMs) Primary spontaneous pneumothoraces are thought to be the result of sudden increases in transpulmonary pressure resulting in alveolar rupture Ruptured alveoli coalesce into blebs, which usually occur apically and can rupture into the pleural space Varying amounts of entering air can lead to a small pneumothorax or complete collapse of the involved lung (Fig 124.5 ) Increased intrathoracic pressure associated with the Valsalva maneuver or forceful inhalation has been associated with spontaneous pneumothorax but there may be no history of any abnormal respirations Genetic predisposition seems to play a role in spontaneous Secondary spontaneous pneumothoraces often result from different pathophysiology; these may involve a defect in the visceral pleura caused by infection, inflammation, connective tissue disorders, or space-occupying lesions FIGURE 124.5 Large pneumothorax involving the entire thorax Atelectatic lung border is marked by arrows Goals of Treatment Tension pneumothorax is a life-threatening emergency and needs to be evacuated immediately Smaller pneumothoraces may be managed conservatively depending on hemodynamic and respiratory response Once patients are stabilized, clinicians should investigate the etiology of the pneumothorax Clinical Considerations Clinical Recognition The peak incidence of spontaneous pneumathorax occurs in the adolescent and young adult years with a male predominance Certain patient populations are at higher risk Children who suffer spontaneous pneumothoraces tend to be tall and thin Cigarette smoking is a significant risk factor in adults and illicit drugs such as marijuana and cocaine have also been associated with pneumothoraces Patients with collagen vascular disorders such as Marfan syndrome are also at increased risk In patients with cystic fibrosis, spontaneous pneumothorax is the second most common pulmonary complication and usually occurs in teenage or young adult patients with advanced, diffuse disease Another group of children with a high incidence of spontaneous pneumothorax are those with pulmonary metastases Children with staphylococcal pneumonia are especially prone to develop unilateral or bilateral pneumothoraces Finally, even though only a very small proportion of asthmatics sustain pneumothoraces, given that asthma is one of the most common diagnoses encountered in the Pediatric ED, these patients represent a fair number of cases Iatrogenic causes of pneumothorax include thoracentesis or central venous catheter insertion, bronchoscopy, aggressive positive pressure ventilation (“barotrauma”), or cardiopulmonary resuscitation Penetrating and blunt trauma to the chest may cause injuries to the lung, pleura, esophagus, trachea, and bronchi, all of which can result in pneumothorax A more detailed discussion of trauma-related causes of pneumothorax can be found in Chapter 115 Thoracic Trauma A tension pneumothorax requires emphasis because this condition may be fatal if not recognized early and attended to rapidly Tension pneumothorax results in air accumulating in the pleural space with each inspiration Whether the entry site of air into the pleural space is through the chest wall, a torn bronchus, or an injured lung, the physiologic result is that of a one-way valve, whereby air continues to accumulate in the pleural cavity with inspiration but cannot be expelled on expiration This phenomenon continues until the intrathoracic pressure on the involved side is so high that no further air can enter the pleural space This results not only in a complete collapse of the ipsilateral lung but also in progressive pressure across the mediastinum This pressure impedes ventilation of the contralateral lung resulting in further compromise Hemodynamic compromise results from rising intrathoracic pressure compromising venous ... Atelectatic lung border is marked by arrows Goals of Treatment Tension pneumothorax is a life-threatening emergency and needs to be evacuated immediately Smaller pneumothoraces may be managed conservatively... sustain pneumothoraces, given that asthma is one of the most common diagnoses encountered in the Pediatric ED, these patients represent a fair number of cases Iatrogenic causes of pneumothorax