Value of postprocedural chest radiographs in the adult intensive care unit

Bedside chest radiography as part of a postcardiac surgery critical care pathway: a means of decreasing utilization without adverse clinical impact

OBJECTIVE

To evaluate the use of bedside chest radiography and patient outcome before and after implementation of a cardiac surgery critical care pathway that included guidelines for bedside radiography.

DESIGN

A cohort observational study.

SETTING

A university hospital in the midwest.

PATIENTS

Three groups, of 100 patients each, undergoing cardiac surgery in 1990, 1991, and 1995.

INTERVENTION

Introduction of a critical care pathway.

MEASUREMENTS

Medical records were retrospectively reviewed in three groups of 100 patients each: before the introduction of the critical care pathway; 2 months after introduction of the pathway in 1991; and 4 yrs after introduction in 1995. Data were analyzed to determine operative risk for each group. Subsequent analyses determined bedside radiography use, total length of hospital stay, and patient outcome (mortality rate, complications requiring intervention, and reoperation) during hospitalization and at outpatient follow-up 15-30 days postdischarge.

RESULTS

Total length of hospital stay was shorter for the 1995 group (7.6+/-6.6 days) compared with other groups (prepathway, 11.1+/-10.3 days; 1991 postpathway, 10.2+/-9.6 days; p<.05). The mean numbers of radiographs per patient were as follows: prepathway, 5.1; 1991 postpathway, 5.2; and 1995 postpathway, 3.3. The mean number of radiographs in the 1995 group was significantly lower (p = .02). More patients had the proposed number of two bedside radiographs described in the pathway in the 1995 group compared with the other groups (prepathway, p<.0001; the two-month postpathway group, p = .01). Twenty-three malpositioned catheters/tubes were found in the prepathway and 1991 groups compared with 11 in the 1995 group (p = .02). No statistically significant difference was found in inpatient complications (mediastinal bleeding, pneumothoraces, and pleural effusions), postdischarge complications, reoperations, or mortality rate.

CONCLUSION

Introduction of a critical care pathway can decrease the use of bedside radiography without adversely affecting near-term patient outcomes.

The efficacy of X-rays after chest tube removal

BACKGROUND

The insertion and subsequent removal of chest tubes are frequently performed procedures. We hypothesize that routine chest radiographs obtained after chest tube removal to confirm the absence of any post-procedure complications have little impact on clinical management.

MATERIALS AND METHODS

A 5-year retrospective study of 73 patients with tube thoracotomies was performed in a level II trauma center's intensive care unit. Patients were identified from billing records for chest tube placement. Medical records and official chest x-ray film reports, both before and after removal, were reviewed, and demographic data were collected.

RESULTS

Of the 73 patients examined, only 8 had postprocedure reports that differed from the preprocedure reports. Two of these 8 patients required reinsertion of a chest tube to treat the recurrence of a significant pneumothorax. However, the decision to reinsert the chest tube was based on the patient's clinical appearance rather than on the x-ray findings.

CONCLUSION

Chest radiography following the removal of chest tubes should not be a routinely performed procedure, but should preferably be based on the good clinical judgement and discrimination of the surgeon.

Utility of postintubation chest radiographs in the intensive care unit

OBJECTIVE

To determine the clinical usefulness of immediate (stat) chest radiographs after endotracheal intubation when performed by experienced critical care personnel.

PATIENTS AND METHODS

This was a prospective study. Endotracheal intubations in an 11-bed intensive care unit and a nine-bed intermediate intensive care unit were included. After intubations were performed by an experienced critical care operator, that individual recorded demographic and procedural data, and predicted radiographic findings on a data collection sheet. Experience at intubation was stratified into four levels of lifetime experience: fewer than 10 procedures, 10-20 procedures, 20-50 procedures, and more than 50 procedures. Radiographic findings evaluated included endotracheal tube position and procedure-related complications. The postintubation chest radiograph was then reviewed and the actual findings were also recorded.

RESULTS

A total of 101 evaluable intubations were recorded, two of which were predicted to show tube malposition. Actual radiographic findings revealed 10 malpositions, three of which were too high and seven were too low (one at the level of the carina). A single witnessed aspiration that occurred during intubation was not radiographically apparent until 24 h later. Only the tube positioned at the carina was felt to be of acute clinical significance or to place the patient at any acute risk.

CONCLUSIONS

The incidence of endotracheal tube malposition after intubation was underestimated. However, when performed by experienced critical care personnel, acutely significant malpositions were rare (one out of 101 intubations). We conclude that, in the absence of specific pulmonary complications, endotracheal intubations performed by experienced operators may be followed by routine, rather than 'stat' chest radiographs.

Delayed pneumothorax and hydrothorax with central venous catheter migration

We report a case of delayed pneumothorax, central venous catheter migration and iatrogenic hydrothorax in a 22-year-old female. The left subclavian central venous catheter initially transfixed the lung apex; pneumothorax occurred 24 h later following initiation of positive pressure ventilation. Lung collapse as a result of the pneumothorax caused catheter migration and hydrothorax. Catheter removal and chest drainage led to an uneventful recovery.

Cannulation of the internal jugular vein: is postprocedural chest radiography always necessary?

OBJECTIVES

To determine whether clinical features can be used in a decision rule to prospectively identify a subgroup of internal jugular catheter placements that are correctly positioned and free from mechanical complications, thus obviating the need for routine postprocedural chest radiographs in selected patients.

DESIGN

Prospective cohort study.

SETTING

Tertiary care teaching hospital.

PATIENTS

A total of 107 consecutive patients who presented to our catheter service for internal jugular catheter insertion because of clinical indications between November 1995 and April 1996. Exclusion criteria were mechanical ventilation, an altered mental status, an age of <15 years, and a height of <152 cm.

INTERVENTIONS

Right or left internal jugular vein catheter placement followed by a postprocedural chest radiograph.

MEASUREMENTS

The operating physician completed a detailed questionnaire for each catheter insertion, designed to detect potential complications and to predict the necessity, or lack of necessity, for a postprocedural chest radiograph. The questionnaire documented patient characteristics, the number of needle passes, difficulty establishing access, operator experience, poor anatomical landmarks, number of previous catheter placements, resistance to wire or catheter advancement, resistance to aspiration of blood or flushing of the catheter ports, sensations in the ear, chest, or arm, and development of signs or symptoms suggestive of pneumothorax. After catheter insertion, chest radiographs were obtained to assess for mechanical complications and malpositioned catheters.

MAIN RESULTS

In 46 cases, the decision rule predicted either a complication or a malposition and, thus, the need for a chest radiograph. In 61 cases, neither was predicted (no chest radiograph was needed). Radiographs confirmed one complication (pneumothorax) and 15 catheter tip malpositions (nine in the right atrium and six in the right axillary vein). Among the 46 cases predicted to have a potential complication or malposition, there were one actual complication (pneumothorax) and six actual malpositions (three axillary vein malpositions and three right atrial malpositions). The positive predictive value of this decision rule is 15%. Among the 61 cases predicted to be free from complications or malpositions and not to require a postprocedural chest radiograph, there were nine unexpected malpositions (three axillary vein malpositions and six right atrial malpositions). The negative predictive value is 85%. The overall sensitivity of the decision rule for detecting complications and malpositions is 44%, and the specificity is 55%.

CONCLUSIONS

In experienced hands, internal jugular venous catheterization is a safe procedure. However, the incidence of axillary vein or right atrial catheter malposition is 14%, and clinical factors alone will not reliably identify malpositioned catheters. Chest radiographs are necessary to ensure correct internal jugular catheter position.

Does the Murphy eye reduce the reliability of chest auscultation in detecting endobronchial intubation?

Bilateral breath sounds are routinely auscultated after endotracheal intubation to verify that the endotracheal tube (ETT) tip is properly positioned. We conducted the present study to ascertain whether the eye of the Murphy tube has an influence on the reliability of auscultation of breath sounds in detecting endobronchial intubation. Twenty patients undergoing scheduled oral and maxillofacial surgery participated in this study. After the induction of general anesthesia, either the Magill tube or the Murphy tube was inserted through the nose into the trachea. The fiberoptic bronchoscope was inserted through the ETT, and the distance from the nares to the carina of the trachea was measured. When breath sounds from the left side of the chest changed and disappeared while the ETT was being advanced, the distance from the nares to the ETT tip was measured. Unilateral auscultatory change was not observed until the ETT tip was advanced beyond the carina and inserted 1.5+/-0.4 cm into the right mainstem bronchus when the Magill tube was used and 2.0+/-0.4 cm when the Murphy tube was used (P < 0.01). Breath sounds disappeared when the ETT tip was further advanced up to 3.2+/-0.3 cm from the carina. We demonstrated that the eye of the Murphy tube reduces the reliability of chest auscultation in detecting endobronchial intubation.

IMPLICATIONS

The Murphy eye was designed to allow ventilation of the lung when the bevel of the endotracheal tube is occluded. We demonstrated that the eye of the Murphy tube reduces the reliability of chest auscultation in detecting endobronchial intubation.

The futility of chest roentgenograms following routine central venous line changes

OBJECTIVE

To demonstrate chest roentgenograms after central venous line changes over a guidewire delay the use of the central lines and increases charges with no change of morbidity or the rate of complication.

METHODS

Retrospective study using the Surgical Intensive Care database followed by a nonrandomized, prospective study of central venous line changes. The total time from the catheter change until chest radiograph confirmation and an analysis of charges was done.

RESULTS

The retrospective study of 1,201 central line changes demonstrated no pneumothorax and two central lines malpositioned. The prospective study of 100 patients demonstrated no pneumothorax and one catheter malpositioned. The average time from completion of the central line change until the radiographic confirmation was 60.2 minutes. The charge for the chest x-ray film was $156.

CONCLUSIONS

The combined studies composed of 1,301 patients demonstrated no pneumothorax and three malpositioned catheters. This study demonstrates that radiographic confirmation of central venous line placement after routine line change is of no benefit as the malpositioned catheters caused no morbidity, produces significant delays and increases medical charges to the patient. Extrapolation predicts an annual reduction of $46,800 in the Vanderbilt Surgical Intensive Care Unit.

The value of routine posttracheostomy chest radiography

OBJECTIVE

This study proposes to evaluate the efficacy of routine posttracheostomy chest radiography.

DESIGN

A retrospective chart review provided the framework of this study.

SETTING

The study took place at a university teaching hospital-level one trauma center.

PATIENTS

The study included 293 patients undergoing elective tracheostomy between 1989 and 1993.

MEASUREMENTS AND RESULTS

Data extracted from the charts included indication for tracheostomy, immediate preoperative and postoperative chest radiograph reports, management changes made secondarily to radiographic findings, including chest tube placement, institution of chest physiotherapy, and need for tracheal tube reposition. Complications were defined as findings not noted on the preoperative radiographs; these were pneumothorax, tube malposition, atelectasis, or clinical information resulting in management changes. All patients received postoperative chest radiographs in the trauma ICU. Statistical analysis of our data was carried out using the chi2 test. Patients with chest tubes in place at the time of surgery were the only group who were excluded so as not to confuse whether pneumothorax developed postoperatively. Of the initial 293 patients, 25 patients were excluded on the basis of having a chest tube. The remaining 268 charts were analyzed; 220 (82%) patients underwent tracheostomy for ventilator-dependent respiratory failure, 31 (12%) due to multiple facial fractures, 6 (2.1%) secondary to penetrating neck wounds, and 11 (4%) as a result of refractory vocal cord edema. One (0.3%) patient was found to have a postoperative 10% apical pneumothorax. Eight (2.4%) patients were found to have postoperative subsegmental atelectasis. There were no significant (p>0.05) management changes implemented as a result of these findings. No new infiltrates, effusions, or malpositioned tubes were noted. Deletion of routine posttracheostomy radiographs would save $52.39 per patient (cost) or $15,350 for 293 patients and $35,453 in total patient charges.

CONCLUSIONS

Abnormalities revealed by routine chest radiography after tracheostomy did not appear to alter patient management frequently enough to warrant the costs. A randomized, prospective study should be performed to analyze the safety of abandoning this practice.

Utility of chest radiographs after guidewire exchanges of central venous catheters

OBJECTIVE

To determine whether chest radiographs are warranted after uncomplicated guidewire exchanges of central venous catheters in patients admitted to a Level I trauma intensive care unit.

DESIGN

Prospective study performed in two phases.

SETTING

Intensive care unit in a Level I trauma center.

PATIENTS

Patients admitted to a Level I trauma center intensive care unit who required central venous catheter guidewire exchanges.

INTERVENTIONS

Criteria for uncomplicated guidewire exchanges were established and followed. A catheter exchange checklist was completed at each procedure, and a chest radiograph was performed after each guidewire exchange. The complications followed were catheter malposition, pneumothorax, hemothorax, and cardiac tamponade. Results were reviewed after 3 mos, and a second phase of the study was initiated in which chest radiographs were obtained selectively and were not performed for uncomplicated exchanges. If obtained, subsequent radiographs were reviewed, and patients were followed to discharge for complications.

MEASUREMENTS AND MAIN RESULTS

One hundred central venous catheter exchanges with postprocedure radiographs were evaluated in phase I. The only complication identified was one malpositioned catheter. In phase II, 110 patients were followed. Eighty-four patients did not have chest radiographs performed after guidewire exchange; 69 patients had subsequent radiographs documenting good placement of the catheter, and 15 patients did not have a radiograph before death (n = 2) or discharge from the hospital (n = 13). Sixteen patients had postprocedure radiographs performed. There were no malpositioned catheters or complications related to guidewire exchanges.

CONCLUSIONS

Chest radiographs are unwarranted after uncomplicated guidewire exchanges of central venous catheters in hemodynamically stable, monitored patients. Eliminating these radiographs will result in significant cost and time savings without adversely affecting patient outcome.

Roentgenographic mimics of pneumonia in the critical care unit

Clinicians are confronted with a complex challenge when a patient is admitted to a critical care unit (CCU) with a significant chest roentgenography (CXR) abnormality. The etiology of a new infiltrate seen on CXR in a patient already in the CCU is more difficult to establish, but is of equal concern.

Postoperative portable chest radiographs: optimum use in thoracic surgery

PURPOSE

Daily portable chest radiographs are routinely ordered in many institutions after thoracic surgery. Our purpose was to assess the efficacy and cost of this practice and to determine the optimum use of postoperative x-ray studies.

METHODS

A prospective review of all portable chest x-ray films after 100 consecutive elective thoracotomies (DRG 75) was conducted. Each x-ray study initiated a three-part survey. First, the surgeon listed whether the x-ray study was routine and the anticipated management had it not been available. The radiologist then interpreted and scored the x-ray study as follows: negative, expected findings; A, minor findings necessitating no intervention; B, minor findings necessitating intervention; or C, major findings necessitating intervention. Finally, the x-ray film and the interpretation were returned to the surgeon. Any interventions necessitated by the x-ray study were recorded.

RESULTS

In 6 months, 99 patients underwent 82 pulmonary resections and 18 other major procedures. In the postoperative period, 769 portable chest x-ray studies were ordered, median five per patient (range 2 to 49). Of these, 731 (95%) were routine and 38 (5%), nonroutine. Severity scores were as follows: negative in 106 (13.8%), A in 558 (72.5%), B in 59 (7.7%), and C in 46 (6.0%). X-ray findings altered management in 43 of 769 studies (5.6%): in 33 routine (4.5%), in 10 nonroutine (26.3%), in 13 A (2.3%), in 22 B (37.3%), and in 8 C (17.4%).

CONCLUSIONS

These results demonstrate that routine daily portable chest x-ray studies have a minimal impact on management. It is, in fact, nonroutine x-ray studies that more often alter management. Had routine portable chest x-ray studies, which cost $114 each in our institution, been limited to one immediately after the operation, only 133 such studies (100 routine and 33 nonroutine) would have been needed in the care of these patients. Elimination of 636 (82.7%) x-ray studies reduces the cost of care by $725 per patient ($286,000 annually). For major thoracic procedures, it is safe, efficacious, and cost effective to eliminate routine postoperative portable chest x-ray studies and order nonroutine portable studies only when clinically indicated.

Complications associated with insertion of jugular venous catheters for hemodialysis: the value of postprocedural radiograph

It is routine in hemodialysis units to require a chest radiograph after the insertion of an internal jugular line for venous access before dialysis is commenced. There are two principal reasons for this: (1) to ensure that no procedural complications have occurred and (2) to verify correct catheter placement. Knowledge of the time delay involved may prompt nephrologists to opt for femoral access (with increased hemodialysis recirculation and need for repeated line placement). The benefit of the postprocedural chest radiograph has never been evaluated in the hemodialysis population. We retrospectively reviewed the data on internal jugular access placement from two large nephrology training centers. Over a 36-month period, 460 internal jugular dialysis catheters were placed in 312 patients. Wherever possible, 15-cm lines were used for the left internal jugular vein and 12-cm lines for the right internal jugular vein. Ultrasound guidance was used in 105 cases (22.8%). There were a total of 90 (19.6%) clinical complications in 62 patients (13.5%). These consisted of carotid artery puncture (n = 35, 7.6%) and hematoma (n = 55, 12%). All of these patients had a normal post-internal jugular chest radiograph. Carotid artery puncture did not occur if ultrasound guidance was used. There was no case of associated pneumothorax. Of the 370 line insertions in 250 patients in whom it was believed clinically that no complication had occurred, the chest radiograph only showed unsuspected line malposition in four cases (1.08%). Routine chest radiographs rarely contribute to the diagnosis of any procedural complications and are of little value after internal jugular access placement, especially if it is believed clinically that no complication occurred.

The utility of routine postoperative chest radiography in the postanesthesia care unit

STUDY OBJECTIVE

To evaluate the clinical significance and cost effectiveness of routine chest radiographs in the postanesthesia care unit (PACU).

DESIGN

Prospective study.

SETTING

University hospital.

PATIENTS

100 patients who were admitted to the PACU following various surgical procedures, and in whom a postoperative chest radiograph was routinely performed.

INTERVENTIONS

Chest radiograph was taken in each study patient soon after admission to the PACU. The indications for postoperative chest radiograph were: thoracotomy (30 patients), thoracoscopy (7), central vein catheterization (CVC) (75), pulmonary artery catheterization (3), and mechanical ventilation (36). A staff anesthesiologist examined each patient, evaluated each chest radiograph, and decided if a treatment action was to be taken. A chest radiologist later evaluated each chest radiograph, and her interpretation was compared with the anesthesiologist's interpretation to assess if this may affect patient management.

MEASUREMENTS AND MAIN RESULTS

The anesthesiologist found eight abnormal chest radiographs (8%): three with pulmonary congestion, four in whom the CVC was in the right atrium, and one with malpositioned CVC. In four patients (4%), the chest radiographic findings directly affected patient management. The radiologist confirmed the anesthesiologist's interpretation and found four additional abnormalities: one pulmonary congestion, one malpositioned CVC, and two chest radiographs, each with a small pneumothorax.

CONCLUSIONS

Abnormal chest radiographic findings resulted in a change in the management of only 4% of the patients. Therefore, the yield of a routine postoperative chest radiograph in the PACU is low. Performing a chest radiograph for a specific indication rather than on a routine basis, may decrease work load and save expenses. Postoperative chest radiography can be safely evaluated by a staff anesthesiologist.

Chest radiography in the ICU

Proper positioning and assessment of abnormalities and complications of the above-mentioned devices have a significant impact on the management of critically ill patients in the intensive care unit (ICU). The timely assessment of new or rapidly evolving findings is critical. Optimal radiographic technique, availability of images to the clinicians, and rapid reporting by the radiologist all serve to maximize the efficacy of bedside chest radiography in the ICU. Sometimes, changes in cardiopulmonary status may only be appreciated on chest radiographs (CXRs). Complications from ventilatory assistance, such as barotrauma, occur frequently and must be detected promptly. The position of monitoring devices, an important component of critical care management, is best checked radiographically. Indications for CXRs and the recommended frequency for repeat follow-up CXRs are based on the existing literature and the consensus of an expert panel formed by the American College of Radiology.

Utility of routine admission chest radiographs in patients with acute gastrointestinal hemorrhage admitted to an intensive care unit

PURPOSE

To determine the diagnostic yield of routine admission chest radiographs in patients with acute gastrointestinal (GI) hemorrhage and clinical predictors of radiographic abnormalities.

PATIENTS AND METHODS

The study was a retrospective series of 202 adult patients with GI hemorrhage admitted to intensive care units at an academic medical center. Routine admission chest radiographs were obtained in 161 patients. These radiographs were reviewed by a study radiologist blinded to the study purpose. The radiologist scored radiographic abnormalities into categories of "minor" or "major," "new" or "previously known," and "with an intervention" or "without an intervention." Nominal logistic regression explored the data for clinical features that identified patients with major new radiographic abnormalities with or without an intervention.

RESULTS

Minor radiographic abnormalities were noted in 23 (14.3%) patients, of whom 17 (10.6%) patients had "new" (previously unknown) abnormalities. No minor abnormality prompted a therapeutic or diagnostic intervention. Major radiographic abnormalities were detected in 21 (13.0%) patients, of whom 19 (11.8%) had new findings. Major new findings prompted interventions in only 9 (5.6%) of patients. A history of lung disease and an abnormal lung physical examination predicted major new radiographic findings (P = 0.0001, sensitivity 79%, negative predictive value 96%). These variables also identified major new abnormalities that prompted interventions (P = 0.007, sensitivity 89%, negative predictive value 99%). Use of the logistic regression model to select patients for admission chest radiographs decreased charges from $1,068 to $580 for each detected major new radiographic abnormality and from $2,254 to $1,087 for major new radiographic abnormalities that prompted an intervention.

CONCLUSION

These data indicate that routine chest radiographs have a low yield in detecting major new radiographic abnormalities in patients with acute GI hemorrhage. Clinical criteria, available at the time of admission, may be useful for selecting patients for chest radiographic evaluations.

Selected topics in chest trauma

Trauma is the leading cause of death of young adults in the United States, and chest trauma is one of the leading causes of trauma-related fatalities. This article presents an approach to the radiological evaluation and diagnosis of pneumothorax, pneumomediastinum, traumatic aortic rupture, and thoracic spine injuries. Also discussed is the radiological assessment of vascular catheters, endotracheal tubes, and thoracostomy tubes.

Fallibility of persistent blood return for confirmation of intravascular catheter placement in patients with hemorrhagic thoracic effusions

Two patients are described with hemorrhagic thoracic effusions who required central venous catheterization. Presumed subclavian and internal jugular vein cannulation, ipsilateral to the hemorrhagic thoracic effusions, was confirmed by the operators in each case by the persistent aspiration of blood. Subsequent clinical and radiologic evaluation revealed that the vascular catheters were introduced into the pleural space. In both individuals, the persistent aspiration of extravascular hemorrhagic fluid mimicked intravascular catheter positioning. Physicians treating patients with hemorrhagic thoracic effusions need to be aware of this potential complication that can result in the delayed resuscitation of hemodynamically unstable patients.

Routine chest radiographs following repositioning of endotracheal tubes are necessary to assess correct position in pediatric patients

Attempts to correctly reposition endotracheal tubes (ETTs) are not always successful in pediatric patients, even when chest radiographs (CXRs) are measured to determine the distance that the ETT deviates from the correct position. We determined the frequency of continued ETT malposition after repositioning in a pediatric intensive care unit (PICU). Forty children with malpositioned ETTs were identified during a 4-month period. After repositioning, ten (25 percent) continued to be malpositioned on the next CXR. Of 47 children with correctly positioned ETTs, only one ETT (2 percent) was found to be incorrectly positioned on the next routine CXR obtained 24 h later. The difference in frequency of ETT malposition between these two groups of children is significant (p < 0.0001). The children were similar in weight and age. Despite repositioning based on measurements taken from a CXR, a large percentage of pediatric patients had continued ETT malposition. However, after radiographic documentation of correct position, we demonstrated that significant movement was uncommon. Routine confirmation of ETT position by CXRs should be considered after repositioning ETTs in pediatric patients.