John G. Brooks

Partial obstruction of endotracheal tubes in children: incidence, etiology, significance.

: We examined 99 endotracheal tubes removed from 81 pediatric patients to determine the incidence of partial endotracheal tube obstruction and predisposing factors. The overall incidence of obstruction was 20.2% (20/99); 14 of the 20 obstructed tubes were occluded less than 50%. General anesthesia during the period of intubation was the only factor significantly associated with an increased incidence of obstruction (p less than 0.05). There was no correlation of obstruction with duration of intubation, the presence of a Murphy-eye side hole, or small tube size. Among the 71 tubes from patients who received general anesthesia, a tube size of 4 mm or less was associated with an increased incidence of obstruction (p less than 0.05). Pressure-flow curves for three different sizes of endotracheal tubes were constructed to determine the increase in resistance produced by different degrees of obstruction. At flow rates that approximated those found in children during quiet breathing, the resistance of tubes that were 50% obstructed was 4 times greater than that found in unobstructed tubes.

Endotracheal Foreign Bodies Difficulties in Diagnosis

The diagnosis of foreign body aspiration into the lower airway depends primarily on the radiographic demonstration of partial bronchial obstruc tion causing localized air trapping or atelectasis, present in 95 per cent of the cases. Èndotracheal foreign bodies may often be visualized directly on high kilovoltage radiographs of the airway or by fluoroscopy. In three of the four cases presented in this report, radiologic evaluation was normal, but endo tracheal foreign bodies were subsequently demonstrated endoscopically. Foreign objects may remain in the trachea for prolonged periods of time, causing persistent coughing, wheezing, or stridor. When there is a clear history or strong suspicion of foreign body aspiration in a patient with persistent symptoms, bronchoscopy should be used for diagnosis and treatment.

The child with simultaneous stridor and wheezing.

We describe 25 patients with simultaneous stridor and wheezing. Twelve patients presented to the emergency department of The Childrens Hospital of Denver over a two-year period; we found an additional 13 in a review of the literature. A combination of two disorders produced stridor and wheezing in six patients, with one condition in the extrathoracic airway and one in the intrathoracic airway. The remaining 19 patients had single lesions, nine with obstruction of the extrathoracic airway and 10 with obstruction of the intrathoracic airway. The causes of stridor and wheezing in these 19 patients fell into three general categories: (1) congenital lesion affecting the airway (eight patients); (2) foreign body in the airway or esophagus (nine patients); and (3) acquired lesion affecting the airway (two patients). All eight patients with congenital lesions developed symptoms by four months of age. All nine patients with an airway or esophageal foreign body were between five and 30 months of age. The history may be misleading, and the physical examination often cannot discriminate among the various likely diagnoses. However, the addition of four plain x-ray views (lateral neck, posteroanterior and lateral chest, and forced expiratory chest) located the site of obstruction in 18 of 25 patients. Barium swallow identified the two patients with vascular rings. Four patients underwent endoscopy to determine the site of obstruction. We make recommendations for evaluation of these patients.

Partial Obstruction of Endotracheal Tubes in Children. Incidence, Etiology, Significance

We examined 99 endotracheal tubes removed from 81 pediatric patients to determine the incidence of partial endotracheal tube obstruction and predisposing factors. The overall incidence of obstruction was 20.2% (20/99); 14 of the 20 obstructed tubes were occluded less than 50%. General anesthesia during the period of intubation was the only factor significantly associated with an increased incidence of obstruction (p less than 0.05). There was no correlation of obstruction with duration of intubation, the presence of a Murphy-eye side hole, or small tube size. Among the 71 tubes from patients who received general anesthesia, a tube size of 4 mm or less was associated with an increased incidence of obstruction (p less than 0.05). Pressure-flow curves for three different sizes of endotracheal tubes were constructed to determine the increase in resistance produced by different degrees of obstruction. At flow rates that approximated those found in children during quiet breathing, the resistance of tubes that were 50% obstructed was 4 times greater than that found in unobstructed tubes.

Pediatric Respiratory Therapy

The new, second edition of this volume is a very useful and well-written combination of practical information and advice, with brief summaries of relevant clinical and pathophysiological background information. With contributions by 14 authors, this book should be of most interest to students and practitioners involved directly or indirectly in the respiratory care of children. This edition includes three new chapters and incorporates much of the relevant new understanding, techniques, and equipment that have emerged in five years since the first edition was published. Development of the cardiopulmonary systems, the pulmonary defense systems, and some nonmetabolic functions of the lung are concisely reviewed in the first two chapters. Some specific diseases and congenital defects that result from or cause abnormalities in these normal patterns are also presented. All the uniquely neonatal clinical, pathophysiological, and therapeutic relevant background information and aspects or respiratory care are contained in chapter 3. A valuable