Postoperative pulmonary complications: An analysis of etiology, diagnosis, prophylaxis and treatment

Abstract

Because of prevalent misconceptions regarding postoperative pulmonary complications, an effort has been made to stress those salient factors in their etiology and diagnosis which will lead to more effective prophylaxis and treatment. It is the author's opinion that atelectasis is the primary pathologic process, and that pneumonia and lung abscess represent advanced stages of the initial atelectasis. Therefore, the time of onset is of major importance in diagnosis. Bronchial obstruction is the sole determining cause of postoperative atelectasis. The quantity and character of the tracheobronchial secretions, and the forces available for expulsion of these secretions, are the factors concerned in the formation of bronchial plugs. Any agent causing an unfavorable change in either factor may precipitate bronchial occlusion. Most often it is the result of an increased amount of thickened secretions with lessened ability to expel them. If infection is superimposed upon the atelectasis, pneumonitis results. Abscess formation follows if the organism is sufficiently virulent and proper treatment is delayed. The following factors, involving the trachoebronchial secretions, powers of expulsion of the secretions, and pulmonary infection, have been discussed and evaluated: operative site, operative sepsis, acute and chronic preëxisting respiratory infection, dental sepsis, anesthesia, incisional trauma with resultant muscle-splinting, constricting dressings, with diaphragmatic limitation, immobility, use of morphia, atropine, and cough sedatives, and the predisposing factors of age, sex, and season. The time of onset has been stressed in diagnosis. Complications appearing in the first five postoperative days are usually atelectasis. Pneumonia seldom occurs prior to the fifth day and most often makes its appearance between the fifth and eighth days. Embolic complications and lung abscesses are usually met after the eighth day. This differentiation is important in the diagnosis of atelectasis from bronchopneumonia, as the clinical picture and even the roentgenogram are often deceptive. Prophylaxis must be directed towards the prevention of bronchial obstruction and pulmonary infection. Each of the several etiologic factors must be given serious consideration as to its potentiality. The following prophylactic measures have been recommended: preoperative care of the respiratory tract, including the prevention of “colds” after admission; incision and operation as atraumatic as possible; avoidance of tight upper abdominal dressings; an individualized anesthetic; judicious use of opiates with preservation of the cough reflex and elimination of pre- and postoperative atropine; semi-Fowler position, supervised deep breathing exercises, and frequent turning after consciousness is regained; encouragement to remove bronchial secretions by cough; carbon dioxide inhalations routinely after abdominal operations; and thyroid extract where the basal metabolic rate is definitely below normal, to prevent embolism. Only the treatment of atelectasis is presented, for if this condition is treated promptly and efficiently pneumonia and lung abscess will not occur. Mention is made of therapy of embolism. Treatment of atelectasis means removal of the obstruction. Measures used in prophylaxis are also utilized in treatment. In addition, postural drainage, with the aid of cough while in the most favorable position for drainage, is recommended. Bronchoscopic aspiration is strongly recommended when the more conservative methods of drainage fail. Two illustrative cases are presented.