Pulmonary sequestration is the result of early isolation of pulmonary tissue from the developing lung bud. Sequestration may occur as intralobar or extralobar, depending on whether the abnormal tissue is located within the pleura or outside of it. The abnormal tissue may have cystic and solid areas with mixtures of air, rudimentary air sacs, and bronchi and chronically inflamed areas. Deterioration during the induction of anesthesia may be a result of communication of the sequestration with the respiratory or gastrointestinal tract, resulting in respiratory distress or GI symptoms. Spontaneous breathing may be more optimal in this regard until the communication can be identified, isolated, and ligated along with the blood supply to the sequestration. Extralobar sequestration, although extrapleural, generally presents at an earlier age with recurrent infections. Arteriovenous malformations are also commonly associated.

It may or may not be, depending on the timing and severity of presentation. A deficiency of bronchial cartilage, bronchial stenosis, or extrinsic vascular compression from the pulmonary artery may result in congenital lobar emphysema, characterized by overinflation and air trapping in the affected lobe with compression atelectasis of adjacent parenchyma and possible mediastinal displacement. Males are affected more often than females. There is progressive respiratory distress in the newborn period or in early infancy. Rapid deterioration requires urgent surgery, and when accompanied by a mediastinal shift, increased intrathoracic pressure, impaired venous return, and decreased cardiac output may result. The diagnosis is made by chest X-ray when bronchovascular marking is present in a hyperlucent area of the lung. Bronchoscopy should be considered in the older infant if there is a possibility of intraluminal obstruction causing lobar emphysema. Surgical excision in the neonate, however, may be an emergent procedure if the lobe is expanding rapidly. Vigorous positive pressure should be avoided during anesthetic induction, and spontaneous ventilation should be preserved. Nitrous oxide should be avoided, as should muscle relaxants.

An anterior mediastinal mass may or may not cause symptoms depending on its encroachment on the tracheobronchial tree and the right heart and pulmonary circulation. Physical diagnosis is not always helpful with regard to the severity of the chest disease, because even patients with more than 50 % airway narrowing may only be symptomatic with orthopnea; the superior vena cava syndrome is relatively rare in pediatric patients [5–7]. Pulmonary function tests may be helpful in demonstrating inspiratory and expiratory compromise. At 8 years of age, a MAC plus good local anesthesia by the surgeon is a very acceptable plan. The patient should also be placed in Semi-Fowler’s position for optimal comfort for ventilation and gas exchange. Premedication with oral benzodiazepines may be a very rational plan and will lessen the patient’s anxiety and improve the chances for a successful operating room course. For patients whose risks increase because of greater than 50 % airway encroachment or significant tumor impingement on the pulmonary circulation or the right ventricle, it is not a bad idea to have a rigid bronchoscope available. In the highest risk situations, when the patient has had episodes of syncopy which may be related to a drop in pulmonary blood flow as a result of right heart obstruction, it may be worthwhile to have both groins prepped and draped and have a perfusion team standing by to cannulate and go on to cardiopulmonary bypass immediately.