upright examinationThirteen-hundred and fifty-four technically adequate chest radiographic films of 167 patiehts were analyzed from November, 1980 to January, 1983. One-hundred and twenty-two (9 percent) were repeated because they were judged to be technically inadequate for interpretation due to motion, improper exposure, or inadequate patient positioning. All those repeated were judged to be adequate for interpretation.

One-hundred and twenty-five others were deleted from the data base due to incomplete data entry. Upon reviewing the data that were entered regarding these films, we were unable to detect any bias in the reasons for incomplete data being entered. Eighty-two percent of the examinations were anteroposterior in projection; 5.7 percent were lateral decubitus studies. The remainder were postero-anterior, crosstable lateral, or other projections. Forty-eight percent were exposed with the patient in a semi-erect position; the rest were equally divided between supine and upright examinations. Reasons for ordering the examinations are summarized in Table 1.

Radiographic Abnormalities

For effect on diagnosis (efficacy type 1), the number of new or increased findings were evaluated on routine radiographic examinations, as well as on those requested post-procedure, to evaluate an existing abnormality, and to evaluate a change in clinical condition. Of 716 routine morning radiographs, 322 (45 percent) demonstrated at least one clinically unsuspected new finding, increased finding, or a tube or catheter malposition.

Radiographs were performed after 305 procedures. Excluding tube or catheter malposition, 18 (5.9 percent) demonstrated new abnormalities that were potentially related to the procedure, Table 2 lists these procedures and the radiographic complications that were found. Causality of these findings is not confirmed by this temporal association, but is inferred. Eighty-one films (26.6 percent) showed at least one tube or catheter that was judged to be in a suboptimal position; 42 of these were the catheters that had been placed immediately prior to the radiographic examination. Do you like the idea to publish medical and pharmaceutical articles in the Internet? If – Yes you may check out the website of Canadian Neighbor Pharmacy.

One-hundred and one pulmonary artery catheters were placed. Of the 24 pulmonary artery catheters noted on post-procedure radiographic examination to require a position adjustment, two were proximal, apparently in the right ventricle or right ventricular outflow tract; three were looped in the right ventricle, right atrium or inferior vena cava; and 19 were thought to be placed distally in segmental or subsegmental pulmonary arteries. inferior vena cava

A total of 143 central venous catheters were placed, including pulmonary artery catheters; five of these were temporally associated with the development of a pneumothorax, two of which were strongly suspected (>90 percent estimated probability) prior to radiographic study and three of which were not suspected. Pneumothoraces were strongly suspected in five cases after central venous catheterization. The subsequent radiographic films demonstrated pneumothoraces on two of these.

Endotracheal intubation was performed on 57 occasions, and nine endotracheal tubes were thought to require adjustment in position after examining the post-procedure film (eight orotracheal tubes and one nasotracheal tube). Eight of these films were available for review. One demonstrated the endotracheal tube in the right mainstem bronchus, one was in the larynx, and six required only minor adjustment due to placement near the carina.

Thoracostomy tubes were placed on 60 occasions. Four of these were thought to be in suboptimal position or were ineffective in resolving the abnormality (three pneumothoraces and one pleural eflusion) for which they were placed.

Of all radiographic examinations performed, 364 (26.9 percent) revealed new or increased abnormalities and 273 (20.2 percent) revealed inadequately positioned catheters. Four hundred sixty-seven (34.5 percent) demonstrated one or more of these abnormalities. Table 3 summarizes type 1 (diagnostic) efficacy of radiographic examinations in the different categories. The incidence of new or increased abnormality was significantly greater (p<0.001) on radiographic films taken to evaluate a change in clinical status than for routine examination.

Diagnostic or Therapeutic Interventions

In order to evaluate the effect of radiographic abnormalities on patient management (efficacy type 2), we evaluated physician responses to the radiographic abnormalities. Of the 716 routine radiographic studies, 71 (9.9 percent) led to further diagnostic procedures (Dx), 131 (18.3 percent) led to changes in therapy (Rx), and 148 (20.7 percent) led to the adjustment of a tube or catheter (Adj). One hundred seventy (23.7 percent) led to Dx or Rx, and 277 (38.7 percent) were followed by Dx, Rx, or Adj. Table 4 compares these figures to those for the other categories of films.

The categories of radiographic examination were then grouped into: 1) routine radiographic examinations, including only those examinations performed as scheduled morning studies; and 2) nonroutine examinations, including those ordered to evaluate a change in clinical condition, those ordered post-procedure, and those ordered to evaluate a known or suspected abnormality. When the 716 routine films were compared to the 572 nonroutine radiographic examinations (Table 5), significant differences (p<0.05) were found between the two groups in the incidence of Dx and Rx actions. Significant differences between the groups were also found for the combined groupings of Dx or Rx, and Dx, Rx or Adj. There was no significant difference between routine and nonroutine radiographic films with respect to the incidence of tube or catheter malposition. The Dx or Rx or Adj column of Table 4 represents the type 2 (therapeutic) efficacy of radiographic examinations of the different categories.

infiltratesAnalysis of all radiographic films in the study period revealed that new or increased infiltrates were documented 152 times, and that these were associated with diagnostic or therapeutic changes 75 times (49 percent). The changes included changes in respiratory therapy, changes in ventilator settings, special radiographic examinations, changes in medications, and collection of cultures.

Pleural fluid was detected as a new or increased finding on 71 occasions and diagnostic or therapeutic maneuvers were initiated in 37 (52 percent) of these, including lateral decubitus radiographic studies 19 times, prior to thoracocentesis in 15 patients.

Pneumothorax was a new or increased finding 58 times, 21 of which were immediately treated with tube thoracostomy, and ten of which were immediately addressed with other specific therapeutic measures such as thoracostomy tube adjustment or ventilator changes. Others underwent special radiographic examinations, or timed follow-up radiographic examinations were scheduled.

Atelectasis (40) and reduced lung volume (35) were associated with diagnostic and/or therapeutic intervention in 60 and 57 percent of the occurrences, respectively. The majority of interventions in patients with these abnormalities were changes in respiratory therapy or ventilator settings, or both.

Table 1—Number aflCU Radiographic Examination» by Category

Category Number .(%)
Admission 48 (3.6)
Routine morning 716 (52.8)
Routine followup 18 (1.3)
Post-procedure 305 (22.5)
Change in clinical condition 124 (9.2)
Evaluate an existing abnormality 143 (10.6)
Total 1354 (100)

Table 2—RadiographicaUy Evident Complications of Procedures

Procedure Number Number (%) with abnormal tube or catheter placement Other complications (number)
Pulmonary artery catheterization 101 24 (23.8) Vascular abnormality (1) Pleural eflusion (1) Mediastinal abnormality (1) Pneumothorax (3)
Tube thoracostomy 60 4 (6.7) Mediastinal abnormality (1) Volume loss (1)Infiltrate (1)Subcutaneous emphysema (3)
Endotrachealintubation 57 9 (15.8) None
Central venous catheterization 42 5 (11.9) Extrathoracic abnormality (1) Pneumothorax (2)
Thoracocentesis 36 Pneumothorax (1)
Bronchoscopy 5 None
Surgery/other 4 Infiltrate (1)Pleural eflusion (1)

Table 3—Type 1 (diagnostic) Efficacy Related to Radiographic Category

Radiographic category Type 1 efficacy* (%)
Admission 72.9
Routine morning 30.2
Routine fbllowup 16.7
Post-procedure 7.9
Change in condition 50.0
Existing abnormality 16.8
All radiographs 26.9

Table 4—Percentage cf Radiographic Films cf Different Categories Evoking an Action (Type 2 or Therapeutic Efficacy)

Category Dx Rx Adj Dx or Rx Dx or Rx or Adj
Admission 33.3 33.3 4.2 50.0 50.0
Routine morning 9.9 18.3 20.7 23.7 38.7
Routine fbllowup 11.1 16.7 0.0 16.7 16.7
Post-procedure 9.2 20.0 26.6 24.6 45.9
Change in condition 12.1 34.7 19.4 42.7 57.3
Existing abnormality 29.4 18.2 12.6 42.6 51.1
All radiographs 12.9 20.7 20.2 28.5 43.4

Table 5—Comparison cf Routine and Nonroutine Radiographs Based on Actions Taken

Action Routine (N = 716) Nonroutine (N = 572) p value (proportionality test) (9)
Dx 9.9% 14.9% 0.003
Rx 18.3% 22.7% 0.025
Adj 20.7% 21.5% 0.358
Dx or Rx 23.7% 33.0% <0.001
Dx, Rx, or Adj 38.7% 49.7% <0.001