Accuracy at radiography and probing for the diagnosis of proximal caries

In 63 teenagers the proximal surfaces of premolars to be extracted for orthodontic reasons and the adjacent surfaces of neighboring teeth, 598 surfaces in all, were examined radiographically and by probing. Direct inspection after extraction revealed that 51% of the surfaces had incipient carious lesions and 5% lesions with cavities. Of the surfaces with cavities 82.1% were correctly diagnosed radiographically if any radiolucency, regardless of its extent, was used as a diagnostic criterion. However, this yielded a false positive rate of 19.6%. If only radioluccncies extending at least into the inner third of the enamel were called positive the true positive rate was 36.7% and the associated false positive rate 1.6%. At a 5% cavity frequency the predictive positive values were 17% and 53%, respectively. Probing yielded a true positive rate of about 29% and a false positive rate of 1.1% with a predictive positive value of 50-57%. All radiolucencies extending into the dentin were associated with cavities. When the most liberal radiographic criterion was used 37.5% of all carious lesions, whether associated with a cavity or not, were detected and 3.8% of sound surfaces were falsely called carious. The corresponding predictive positive value at the actual rate of incipient lesions and lesions with cavities was 92.6%.     

Complications and consequences of endotracheal intubation and tracheotomy: A prospective study of 150 critically ill adult patients

A prospective study of the complications and consequences of translaryngeal endotracheal intubation and tracheotomy was conducted on 150 critically ill adult patients. Adverse consequences occurred in 62 percent of all endotracheal intubations and in 66 percent of all tracheotomies during placement and use of the artificial airways. The most frequent problems during endotracheal intubation were excessive cuff pressure requirements (19 percent), self-extubation (13 percent) and inability to seal the airway (11 percent). Patient discomfort and difficulty in suctioning tracheobronchial secretions were very uncommon. Problems with tracheotomy included stomal infection (36 percent), stomal hemorrhage (36 percent), excessive cuff pressure requirements (23 percent) and subcutaneous emphysema or pneumomediastinum (13 percent). Complications of tracheotomy were judged to be more severe than those of endotracheal intubation. Follow-up studies of survivors revealed a high prevalence of tracheal stenosis after tracheotomy (65 percent) and significantly less after endotracheal intubation (19 percent) (p < 0.01). Thirty-nine of 41 (95 percent) patients with endotracheal intubation and 20 of 22 (91 percent) patients with tracheotomy had laryngotracheal injury at autopsy. Ulcers on the posterior aspect of the true vocal cords were found at autopsy in 51 percent of the patients who died after endotracheal intubation. There was no significant relationship between the duration of endotracheal intubation or tracheotomy and the over-all amount of laryngotracheal injury at autopsy, although patients with prolonged endotracheal intubation followed by tracheotomy had more laryngeal injury at autopsy (P = 0.06) and more frequent tracheal stenosis (P = 0.05) than patients with short-term endotracheal intubation followed by tracheotomy. Adverse effects of both endotracheal intubation and tracheotomy are common. The value of tracheotomy when an artificial airway is required for periods as long as three weeks is not supported by data obtained in this study.