Routine portable chest radiographs in the medical intensive care unit: effects and costs

Efficacy of the scatter correction algorithm in portable chest radiography

PURPOSE

Portable chest radiographs (CXRs) continue to be a vital diagnostic tool for emergency and critical care medicine. The scatter correction algorithm (SCA) is a post-processing algorithm aiming to reduce scatter within portable images. This study aimed to assess whether the SCA improved image quality (IQ) in portable CXRs.

METHODS

Objective and subjective IQ assessments were undertaken on both phantom and clinical images, respectively. For objective analysis, attenuators were placed on the anterior surface of the patient's thorax to simulate pathologies present within uniform regions of the phantom's lung and heart. Phantom CXRs were acquired with three different tube-current-times (mAs). Phantom images were processed with different SCA strengths. Contrast to noise ratios (CNR) within the attenuator were determined for each algorithm strength and compared to non-SCA images. For subjective analysis, two independent radiologists graded 30 clinical images with and without the SCA activated. The images were graded for IQ in different anatomical structures and overall diagnostic confidence.

RESULTS

Objectively, most strengths of the SCA improved the CNR in both regions. However, a detrimental effect was recorded for some algorithm strengths in regions of high contrast. Subjectively, both observers recorded the SCA significantly improved IQ in clinical CXRs in all anatomical regions. Observers indicated the greatest improvement in the lung and hilar regions, and least improvement in the chest wall and bone. All images with and without the SCA were deemed diagnostic.

CONCLUSION

This study shows the potential radiation dose neutral IQ improvement when using an SCA in clinical patient CXRs.

Superiority of Supervised Machine Learning on Reading Chest X-Rays in Intensive Care Units

Purpose: Portable chest radiographs are diagnostically indispensable in intensive care units (ICU). This study aimed to determine if the proposed machine learning technique increased in accuracy as the number of radiograph readings increased and if it was accurate in a clinical setting.

Methods: Two independent data sets of portable chest radiographs (n = 380, a single Japanese hospital; n = 1,720, The National Institution of Health [NIH] ChestX-ray8 dataset) were analyzed. Each data set was divided training data and study data. Images were classified as atelectasis, pleural effusion, pneumonia, or no emergency. DenseNet-121, as a pre-trained deep convolutional neural network was used and ensemble learning was performed on the best-performing algorithms. Diagnostic accuracy and processing time were compared to those of ICU physicians.

Results: In the single Japanese hospital data, the area under the curve (AUC) of diagnostic accuracy was 0.768. The area under the curve (AUC) of diagnostic accuracy significantly improved as the number of radiograph readings increased from 25 to 100% in the NIH data set. The AUC was higher than 0.9 for all categories toward the end of training with a large sample size. The time to complete 53 radiographs by machine learning was 70 times faster than the time taken by ICU physicians (9.66 s vs. 12 min). The diagnostic accuracy was higher by machine learning than by ICU physicians in most categories (atelectasis, AUC 0.744 vs. 0.555, P < 0.05; pleural effusion, 0.856 vs. 0.706, P < 0.01; pneumonia, 0.720 vs. 0.744, P = 0.88; no emergency, 0.751 vs. 0.698, P = 0.47).

Conclusions: We developed an automatic detection system for portable chest radiographs in ICU setting; its performance was superior and quite faster than ICU physicians.

Do We Need Postoperative Chest Radiographs After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis?

STUDY DESIGN

The question was addressed in three ways: (1) a query of Kids' Inpatient Database (KID) to obtain nationally representative data; (2) retrospective review of cases at a single institution; (3) survey of Scoliosis Research Society (SRS) spine surgeons.

OBJECTIVES

Evaluate the rate of immediate postoperative pulmonary complications, risk factors, and relevant surgeon practice patterns, to determine the usefulness of routine postoperative chest radiographs after posterior spinal instrumentation and fusion (PSIF) for adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Routine postoperative chest radiography after PSIF for AIS is performed in many institutions to evaluate for acute pulmonary complications, particularly pneumothorax (PTX). The incidence of pneumothorax and its effect on management is unknown.

METHODS

The frequency of PTX and surgical intervention were recorded. We evaluated associations between PTX and patient demographics or comorbidities, as well as survey respondent demographics and their practice patterns.

RESULTS

In the KID data sets, the risk of PTX after PSIF for AIS patients was 0.3% (30/9,036), with intervention required in 13.3% (4/30) of PTX-positive patients (0.04% of all cases). Review of cases at our institution revealed a PTX rate of 3.3% (8/244) by radiology report. No surgical intervention was required. Patients with PTX had, on average, an increased number of vertebrae fused (p = .012), a proximal thoracic scoliosis curve location (p = .009), and/or an intraoperative blood transfusion (p = .002). SRS respondents reported a PTX risk of 0.8% (87/11,318), and 32.2% (89/276) of respondents indicated routine use of postoperative chest radiographs. Of those, 46.1% (41/89) specified willingness to change practice patterns if provided evidence of low PTX rates.

CONCLUSIONS

Pneumothorax is uncommon after PSIF for AIS. The need for intervention is even less common. Routine postoperative chest radiographs are of questionable value after PSIF for AIS.

LEVEL OF EVIDENCE

Level III.

Trends in Use of Daily Chest Radiographs Among US Adults Receiving Mechanical Ventilation

IMPORTANCE

Guidelines from December 2011 recommended against obtaining daily chest radiographs (CXRs) for patients requiring mechanical ventilation (MV). Daily CXR use for patients receiving MV in US hospitals is unknown and, if high, may represent an opportunity to reduce low-value care and unnecessary radiation.

OBJECTIVES

To determine frequency of daily CXR use for US patients receiving MV, assess variability across hospitals, and evaluate whether use has decreased over time.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of hospitalized adults (aged ≥18 years) receiving MV for 3 days or longer. Mechanical ventilation was defined by having an International Classification of Diseases, Ninth Revision, Clinical Modification code of 96.7x and an MV charge on more than 1 hospital day. Hospital discharges in the Premier Perspectives database were examined from July 1, 2008, to December 31, 2014. Data analysis was conducted from July 28, 2017, to December 13, 2017.

EXPOSURES

Hospital discharge date (quarter of the year) and hospital in which patients received MV.

MAIN OUTCOMES AND MEASURES

The outcome was daily CXR use (up to 7 days) during MV. We used standard statistics to describe CXR use, multilevel multivariable regression modeling with adjusted median odds ratio (OR) to evaluate variability by hospital, and multivariable piecewise regression (breakpoint: fourth quarter of 2011) with adjusted OR to evaluate time trends and response to guideline recommendations.

RESULTS

The primary cohort included 512 518 patients receiving MV (mean [SD] age, 63.0 [16.1] years; 46% female) in 416 hospitals, of whom 321 093 (63%) received daily CXRs. Wide variability was seen across hospitals; hospitals performed daily CXRs on a median of 66% of patients (interquartile range, 50%-77%; full range, 12%-97%). The adjusted median OR was 2.43 (95% CI, 2.29-2.59), suggesting the same patient had 2.43-fold higher odds of receiving a daily CXR if admitted to a higher- vs lower-use hospital; the odds of receiving daily CXRs were unchanged through quarter 3 of 2011 (adjusted OR, 1.00; 95% CI, 0.99-1.01), after which there was a 3% relative reduction in the odds of daily CXR use per quarter (adjusted OR, 0.97; 95% CI, 0.96-0.98).

CONCLUSIONS AND RELEVANCE

Three-fifths of US patients receiving MV also received daily CXRs from 2008 to 2014, although use declined slowly after new guidelines were published. The hospital at which a patient received care was associated with the odds of daily CXR receipt.

Routine chest X-ray is unnecessary after ultrasound-guided central venous line placement in the operating room

BACKGROUND

Central venous catheters (CVC) can be useful for perioperative monitoring and insertion has low complication rates. However, routine post insertion chest X-rays have become standard of care and contribute to health care costs with limited impact on patient management.

METHODS

200 patient charts who underwent pancreaticoduodenectomy with central line placement and early line removal were reviewed for clinical complications related to central line placement as well as radiographic evidence of malpositioning. A cost analysis was performed to estimate savings if CXR had not been performed across routine surgical procedures requiring central access.

RESULTS

In 200 central line placements for Whipple procedures, 198 lines were placed in the right internal jugular and 2 were placed in the subclavian. No cases of pneumothorax or hemothorax were identified and 30 (15.3%) of CVCs were improperly positioned. Only 1 (0.5%) of these was deemed clinically significant and repositioned after the CXR was performed.

CONCLUSION

Routine CXR consumes valuable time and resources (≅$155,000 annually) and rarely affects management. Selection should be guided by clinical factors.

Adding value to daily chest X-rays in the ICU through education, restricted daily orders and indication-based prompting

Background

Chest X-rays (CXRs) are traditionally obtained daily in all patients on invasive mechanical ventilation (IMV) in the intensive care unit (ICU). We sought to reduce overutilisation of CXRs obtained in the ICU, using a multifaceted intervention to eliminate automated daily studies.

Methods

We first educated ICU staff about the low diagnostic yield of automated daily CXRs, then removed the ‘daily’ option from the electronic health records-based ordering system, and added a query (CXR indicated or not indicated) to the ICU daily rounding checklist to prompt a CXR order when clinically warranted. We built a report from billing codes, focusing on all CXRs obtained on IMV census days in the medical (MICU) and surgical (SICU) ICUs, excluding the day of admission and days that a procedure warranting CXR was performed. This generated the number of CXRs obtained every 1000 ‘included’ ventilator days (IVDs), the latter defined as not having an ‘absolute’ clinical indication for CXR.

Results

The average monthly number of CXRs on an IVD decreased from 919±90 (95% CI 877 to 963) to 330±87 (95% CI 295 to 354) per 1000 IVDs in the MICU, and from 995±69 (95% CI 947 to 1055) to 649±133 (95% CI 593 to 697) in the SICU. This yielded an estimated 1830 to 2066 CXRs avoided over 2 years and an estimated annual savings of $191 600 to $224 200. There was no increase in reported adverse events.

Conclusion

ICUs can safely transition to a higher value strategy of indication-based chest imaging by educating staff, eliminating the ‘daily’ order option and adding a simplified prompt to avoid missing clinically indicated CXRs.

Abnormal Admission Chest X-Ray and MEWS as ICU Outcome Predictors in a Sub-Saharan Tertiary Hospital: A Prospective Observational Study

Background. Critical care in Uganda is a neglected speciality and deemed costly with limited funding/prioritization. We studied admission X-ray and MEWS as mortality predictors of ICU patients requiring mechanical ventilation. Materials and Methods. We did a cross-sectional study in Mulago Hospital ICU and 87 patients for mechanical ventilation were recruited with mortality as the outcome of interest. Chest X-ray results were the main independent variable and MEWS was also gotten for all patients. Results. We recruited 87 patients; most were males (60.92%), aged between 16 and 45 years (59.77%), and most admissions for mechanical ventilation were from the Trauma Unit (30.77%). Forty-one (47.13%) of the 87 patients died and of these 34 (53.13%) had an abnormal CXR with an insignificant IRR = 1.75 (0.90–3.38) (p = 0.062). Patients with MEWS ≥ 5 (p values = 0.018) and/or having an abnormal superior mediastinum (p values = 0.013) showed a positive association with mortality while having a MEWS ≥ 5 had an incidence risk ratio = 3.29 (1.00–12.02) (p = 0.018). MEWS was a good predictor of mortality (predictive value = 0.6739). Conclusion. Trauma (31%) caused most ICU admissions, having an abnormal admission chest X-rays positively associated with mortality and a high MEWS was also a good predictor of mortality.

Test-Ordering Strategy in the Intensive Care Unit

The objective of this study was to assess the effect of an intervention designed to reduce utilization of portable chest x-rays (CXRs) in the intensive care unit (ICU). In this prospective observational study, patients representing 2734 consecutive admissions over a 35-month period were studied. Data collected from the comprehensive ICU database included patient days, ventilator days, number of admissions to the unit, number of CXRs ordered, costs for CXR, Acute Physiology and Chronic Health Evaluation II (Apache II) scores, ICU length of stay (LOS), length of mechanical ventilation, inadvertent extubations from mechanical ventilation, and reintubation within 48 hours of planned extubation. There was a 22.5% reduction in the rate CXR utilization during the study period, resulting in a $109,968 cost savings, and these savings were not associated with any adverse clinical outcomes.

Implementation of a quality improvement initiative to reduce daily chest radiographs in the intensive care unit

OBJECTIVE

To reduce the number of routine chest radiographs (CXRs) done in a tertiary care intensive care unit (ICU).

METHODS

Using a quality improvement approach, we measured the number of CXRs done per patient-day before (15 June 2010-15 June 2011) and after (15 June 2011-15 June 2012) a multipronged intervention in a 15-bed medical-surgical ICU in a 350-bed tertiary care teaching hospital. We studied a total of 1492 patients who were admitted to this ICU-738 patients during the preintervention period and 754 patients during the postintervention period. Interventions were education for the ICU house staff, developing indications for routine CXRs on the computer order-entry system, and visual posters/signage to remind ICU staff that there were no indications for routine, daily CXRs. The primary outcome was the number of CXRs per patient-day, but we also measured CTs of the chest, mechanical ventilator days, length of ICU stay and ICU and hospital mortality.

RESULTS

There were 0.73 CXRs per patient-day done during the preintervention period and 0.54 CXRs per patient-day done during the postintervention period, a 26% reduction. There were no differences between the periods in age, sex or severity of illness (Acute Physiology and Chronic Health Evaluation (APACHE) II score) of the patients, number of chest CTs, mechanical ventilator days, length of ICU stay and ICU or hospital mortality.

CONCLUSIONS

A quality improvement that includes education, reminders of appropriate indications and computerised decision support can decrease the number of routine CXRs in an ICU.

Defining indications for selective chest radiography in the first 24 hours after cardiac surgery

OBJECTIVE

In the intensive-care unit (ICU), chest radiographs (CXRs) are frequently obtained routinely for postoperative cardiac surgery patients, despite the fact that the efficacy of routine CXRs is known to be low. We investigated the efficacy and safety of CXRs performed after cardiac surgery for specified indications only.

METHODS

In this observational cohort study, we prospectively included all patients who underwent conventional major cardiac surgery by median sternotomy in the year 2012. On-demand CXRs could be obtained during the first postoperative period for specified indications only. A routine control CXR was performed on the morning of the first postoperative day for all patients who had not undergone a CXR before that time. The diagnostic and therapeutic efficacy values were calculated for all CXRs. Differences were tested using Fisher's exact test or χ(2) analysis.

RESULTS

A total of 1102 consecutive cardiac surgery patients were included in this study. The diagnostic efficacy of CXRs for major abnormalities was higher for the postoperative on-demand CXRs (n = 301; 27%) than for the routine CXRs taken the morning after surgery (n = 801; 73%) (6.6% vs 2.7%, P = .004). The therapeutic efficacy was higher for the on-demand CXRs, whereas the need for intervention after the next-morning, routine CXRs was limited to 5 patients (4.0% vs 0.6%, P < .001). None of these patients experienced a major adverse event.

CONCLUSIONS

Defining clear indications for selective CXRs after cardiac surgery is effective and seems to be safe. This approach may significantly reduce the total number of CXRs performed, and will increase their efficacy.

Postprocedural chest radiograph: Impact on the management in critical care unit

Postprocedural chest radiograph is done to illustrate the position of endotracheal tubes (ETTs), nasogastric and drainage tubes, indwelling catheters, and intravascular lines or any other lifesaving devices to confirm their position. These devices are intended to save life, but may be life-threatening if in the wrong place. The incidence of malposition and complications ranges from 3% to 14%, respectively. The portable chest radiograph is of tremendous value, inexpensive and can be obtained quickly at the patient's bedside in any location of the hospital. A systemic literature search was performed in PubMed and the Cochranre library by setting up the search using either single text word or combinations. Those studies were also included where the chest radiograph was compared with other imaging modalities. Its clinical efficacy, cost-effectiveness and practicality allow anesthesiologist to evaluate the post-procedural position and complications of ETT, indwelling catheters, and multi lumen intravascular lines. Knowledge of the radiological features of commonly used devices is of utmost importance.

The value of routine chest radiographs after minimally invasive cardiac surgery: an observational cohort study

Background

Chest radiographs (CXRs) are obtained frequently in postoperative cardiac surgery patients. The diagnostic and therapeutic efficacy of routine CXRs is known to be low and the discussion regarding the safety of abandoning these CXRs after cardiac surgery is still ongoing. We investigated the value of routine CXRs directly after minimally invasive cardiac surgery.

Methods

We prospectively included all patients who underwent minimally invasive cardiac surgery by port access, ministernotomy or bilateral video-assisted thoracoscopy (VATS) in the year 2012. A direct postoperative CXR was performed on all patients at ICU arrival. All CXR findings were noted, including whether they led to an intervention or not. The results were compared to the postoperative CXR results in patients who underwent conventional cardiac surgery by full median sternotomy over the same period.

Main results

A total of 249 consecutive patients were included. Most of these patients underwent valve surgery, rhythm surgery or a combination of both. The diagnostic efficacy for minor findings was highest in the port access and bilateral VATS groups (56% and 63% versus 28% and 45%) (p < 0.005). The diagnostic efficacy for major findings was also higher in these groups (8.9% and 11% versus 4.3% and 3.8%) (p = 0.010). The need for an intervention was most common after minimally invasive surgery by port access, although this difference was not statistically significant (p = 0.056).

Conclusions

The diagnostic efficacy of routine CXRs performed after minimally invasive cardiac surgery by port access or bilateral VATS is higher than the efficacy of CXRs performed after conventional cardiac surgery. A routine CXR after these procedures should still be considered.

Evaluation of the Clinical Utility of Routine Daily Chest Radiography in Intensive Care Unit Patients With Tracheostomy Tubes: A Retrospective Review

BACKGROUND

The utilization of imaging procedures is under scrutiny due to high costs and radiation exposure to patients and staff associated with some radiologic procedures. Within our institution's intensive care unit (ICU), it is common for patients to undergo chest radiography (CR) not only immediately following tracheostomy tube placement but also on a daily basis, irrespective of the patient's clinical status. We hypothesize that the clinical utility of performing routine daily CR on patients with tracheostomy tubes is low and leads to unnecessary financial cost.

METHODS

A retrospective medical chart review was done on 761 CRs performed on 79 ICU patients with tracheostomy from April 2010 to July 2011. We searched the radiology reports of the 761 CRs for the presence of new radiographically detected complications and reviewed medical records to determine which complications were clinically suspected and which radiology reports led to changes in patient management.

RESULTS

Of the 761 CRs, only 18 (2.3%) radiographs revealed new complications. All complications were clinically suspected prior to imaging. Only 5 (0.7%) complications resulted in a management change. The most common management changes were a change in antibiotic regimen (0.3%) and ordering of diuretics (0.3%).

CONCLUSIONS

Routine daily imaging of patients with tracheostomy in an ICU provides little clinical utility, and CR in this population should be performed selectively based on the patient's clinical status.

Significant changes in the practice of chest radiography in Dutch intensive care units: a web-based survey

Background

ICU patients frequently undergo chest radiographs (CXRs). The diagnostic and therapeutic efficacy of routine CXRs are now known to be low, but the discussion regarding specific indications for CXRs in critically ill patients and the safety of abandoning routine CXRs is still ongoing. We performed a survey of Dutch intensivists on the current practice of chest radiography in their departments.

Methods

Web-based questionnaires, containing questions regarding ICU characteristics, ICU patients, daily CXR strategies, indications for routine CXRs and the practice of radiologic evaluation, were sent to the medical directors of all adult ICUs in the Netherlands. CXR strategies were compared between all academic and non-academic hospitals and between ICUs of different sizes. A comparison was made between the survey results obtained in 2006 and 2013.

Results

Of the 83 ICUs that were contacted, 69 (83%) responded to the survey. Only 7% of responding ICUs were currently performing daily routine CXRs for all patients, and 61% of the responding ICUs were said never to perform CXRs on a routine basis. A daily meeting with a radiologist is an established practice in 72% of the responding ICUs and is judged to be important or even essential by those ICUs. The therapeutic efficacy of routine CXRs was assumed by intensivists to be lower than 10% or to be between 10 and 20%. The efficacy of ‘on-demand’ CXRs was assumed to be between 10 and 60%. There is a consensus between intensivists to perform a routine CXR after endotracheal intubation, chest tube placement or central venous catheterization.

Conclusion

The strategy of daily routine CXRs for critically ill and mechanically ventilated patients has turned from being a common practice in 2006 to a rare current practice. Other routine strategies and an ‘on-demand only’ strategy have become more popular. Intensivists still assume the value of CXRs to be higher than the efficacy that is reported in the literature.

Routine chest x-rays in intensive care units: a systematic review and meta-analysis

Introduction

Chest x-rays (CXRs) are the most frequent radiological tests performed in the intensive care unit (ICU). However, the utility of performing daily routine CXRs is unclear.

Methods

We searched Medline and Embase (1948 to March 2011) for randomized and quasi-randomized controlled trials (RCTs) and before-after observational studies comparing a strategy of routine CXRs to a more restrictive approach with CXRs performed to investigate clinical changes among critically ill adults or children. In duplicate, we extracted data on the CXR strategy, study quality and clinical outcomes (ICU and hospital mortality; duration of mechanical ventilation and ICU and hospital stay).

Results

Nine studies (39,358 CXRs; 9,611 patients) were included in the meta-analysis. Three trials (N = 870) of moderate to good quality provided information on the safety of a restrictive routine CXR strategy; only one trial systematically assessed for missed findings. Pooled data from trials showed no evidence of effect of a restrictive approach on ICU mortality (risk ratio [RR] 1.04, 95% confidence interval [CI] 0.84 to 1.28, P = 0.72; two trials, N = 776), hospital mortality (RR 0.98, 95% CI 0.68 to 1.41, P = 0.91; two trials, N = 259), ICU length of stay (weighted mean difference [WMD] -0.86 days, 95% CI -2.38 to 0.66 days, P = 0.27; three trials, N = 870), hospital length of stay (WMD -2.50 days, 95% CI -6.62 to 1.61 days, P = 0.23; two trials, N = 259), or duration of mechanical ventilation (WMD -0.30 days, 95% CI -1.48 to 0.89 days, P = 0.62; three trials, N = 705). Adding data from six observational studies, one of which systematically screened for missed findings, gave similar results.

Conclusions

This meta-analysis did not detect any harm associated with a restrictive chest radiograph strategy. However, confidence intervals were wide and harm was not rigorously assessed. Therefore, the safety of abandoning routine CXRs in patients admitted to the ICU remains uncertain.

Radiation exposure from diagnostic imaging in the pediatric intensive care unit

OBJECTIVE

To determine the range of radiation exposure from diagnostic imaging in children requiring mechanical ventilation.

DESIGN

Prospective, observational.

SETTING

Tertiary pediatric critical care unit.

PATIENTS

We enrolled pediatric critical care unit patients requiring mechanical ventilation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Thoracic radiation exposure while the patient was in the pediatric critical care unit was measured using a small, radiolucent dosimeter secured to the anterior chest wall. Demographic data, diagnoses, and number and type of radiographic procedures were recorded. Differences between exposures by admission diagnoses were analyzed by rank sum test. Relationships between exposure and risk factors were assessed using multiple linear regression and Pearson correlation. Sixty-nine subjects were enrolled over a 175-day period. Subjects experienced a mean (± SD) of 11 ± 11 days of mechanical ventilation during which they underwent a mean of 14 ± 16 chest radiographs and 5 ± 4 other plain films. Subjects who had only plain radiographic studies (CXR group) had a median thoracic exposure of 1.02 (range, 0.13-28.26) mGy and a median daily exposure of 0.16 (range, 0.02-1.99) mGy/day. Subjects who had computed tomography and/or fluoroscopy studies in addition to plain radiographs (CXR+ group) had a median total thoracic exposure of 3.71 (range, 0.77-33.41) mGy and median daily exposure of 0.37 (range, 0.04-3.71) mGy/day, both of which were significantly higher than for subjects in the CXR group. There was no significant difference in average daily exposures according to admission diagnoses and daily exposure could not be predicted from a combination of variables, including age, body mass index, gender, or length of stay. Total number of radiologic studies was correlated, as expected, with duration of ventilation (r = 0.941, p < .0001). Exposure was significantly higher in patients who underwent computed tomography scans or fluoroscopy studies than in patients who only had plain radiography.

CONCLUSIONS

Ventilated pediatric intensive care unit patients experienced an average daily thoracic radiation exposure above background environmental exposure and exposure varied widely, but exposures would not be expected to cause acute or chronic toxicity. Overall patient exposures were less than that received from 1 yr of natural background radiation.

[Prediction of the clinical usefulness of routine chest X-rays in a traumatology ICU]

BACKGROUND

The clinical value of routine chest X-rays in critical care has been questioned, but has not been studied in the trauma environment to date. The objective of this study was to identify easy to use clinical predictors of utility in this setting.

MATERIAL AND METHODS

A prospective observational study was made in an 8-bed traumatology ICU. Severe trauma patients (ISS > 15), aged 15 or older and admitted for 48 h or longer were included. Pregnant women and radiographs obtained during initial care or for reasons other than routine indication were excluded. A staff physician, separated from clinical duties, independently reviewed the films in search of changes, as described in a closed checklist. Following closed criteria, the attending physicians reported previous day clinical events and changes in clinical management after chest X-ray obtainment. Demographic and epidemiological data were also recorded. The associations among variables were studied by univariate and multivariate analysis.

RESULTS

A total of 1440 routine chest X-rays were obtained from 138 consecutive patients during one year. Young males prevailed (82%; 39 ± 16 years). The most common process was severe blunt trauma (97%). Fifty-two percent suffered severe chest trauma. The mean length of stay was 12.9 ± 10.1 days. Mechanical ventilation was used in 86.8% of the cases. A median of 10.4 ± 9.3 films were obtained from each patient. A total of 14% of the X-rays showed changes, most commonly malpositioning of an indwelling device (6.8%) or infiltrates (4.9%). Those findings led to a change in care in 84.6% of the cases. Multivariate analysis identified the following significant (p < 0.05) risk factors for radiographic changes: first two days of evolution, mechanical ventilation, worsening of PaO₂/FiO₂, worsening of lung compliance and changes in respiratory secretions.

CONCLUSIONS

Based on the results obtained, the risk of not identifying dangerous conditions by restricting routine chest X-rays prescription to the described conditions is low. Observing this policy would probably mean substantial savings and a reduction in radiation exposure.

An integrated approach for prescribing fewer chest x-rays in the ICU

Chest x-rays (CXRs) are the main imaging tool in intensive care units (ICUs). CXRs also are associated with concerns inherent to their use, considering both healthcare organization and patient perspectives. In recent years, several studies have focussed on the feasibility of lowering the number of bedside CXRs performed in the ICU. Such a decrease may result from two independent and complementary processes: a raw reduction of CXRs due to the elimination of unnecessary investigations, and replacement of the CXR by an alternative technique. The goal of this review is to outline emblematic examples corresponding to these two processes. The first part of the review concerns the accumulation of evidence-based data for abandoning daily routine CXRs in mechanically ventilated patients and adopting an on-demand prescription strategy. The second part of the review addresses the use of alternative techniques to CXRs. This part begins with the presentation of ultrasonography or capnography combined with epigastric auscultation for ensuring the correct position of enteral feeding tubes. Ultrasonography is then also presented as an alternative to CXR for diagnosing and monitoring pneumothoraces, as well as a valuable post-procedural technique after central venous catheter insertion. The combination of the emblematic examples presented in this review supports an integrated global approach for decreasing the number of CXRs ordered in the ICU.

Bedside ultrasound can safely eliminate the need for chest radiographs after central venous catheter placement: CVC sono in the surgical ICU (SICU)

BACKGROUND

Real-time ultrasound guidance of central venous catheter (CVC)/peripherally inserted central catheter (PICC) insertion improves safety and efficacy. We hypothesized that a more robust ultrasound surveillance technique incorporating thoracic, vascular, and cardiac views-the CVC sono-would avoid the need for chest radiography to realize cost and efficiency gains.

METHODS

We conducted a prospective data collection in a high-volume, urban, academic SICU. A single surgical intensivist, blinded to the results of chest radiography, performed all CVC sonos post-insertion. Catheter malposition was defined as location extrinsic to the superior vena cava and determined by a board-certified radiologist on chest radiography. CVC sono consisted of (1) mechanical complications screen (hemo-, pneumothorax), (2) intravenous tip screen, (3) intracardiac tip screen. The result of CVC sono was compared with chest radiography.

RESULTS

CVC sono evaluated 83 catheters (42 CVCs and 41 PICCs) and was considered technically adequate in 59 (71%). Incomplete studies were significantly more common in those with chest tubes (P = 0.02), but not in those with cervical collars (P = 0.07), an open abdomen (P = 0.28), or BMI > 40 (P = 0.33). Mean CVC sono time was 10.8 min, compared with chest radiography of 75.3 min (P < 0.001). No hemo-pneumothoraces developed. Presence of multiple indwelling central catheters (>1 CVC) trended for inaccurate CVC sono for catheter malposition (accuracy: 79% versus 93%, P = 0.11).

CONCLUSION

A novel ultrasound technique, CVC sono eliminated the need for chest radiography in most patients after CVC/PICC insertion, saving time and money. Those with multiple indwelling central catheters may still require post-insertion conventional chest radiography.

Comparison of routine and on-demand prescription of chest radiographs in mechanically ventilated adults: a multicentre, cluster-randomised, two-period crossover study

BACKGROUND

Present guidelines recommend routine daily chest radiographs for mechanically ventilated patients in intensive care units. However, some units use an on-demand strategy, in which chest radiographs are done only if warranted by the patient's clinical status. By comparison between routine and on-demand strategies, we aimed to establish which strategy was more efficient and effective for optimum patient care.

METHODS

In a cluster-randomised, open-label crossover study, we randomly assigned 21 intensive care units at 18 hospitals in France to use a routine or an on-demand strategy for prescription of chest radiographs during the first of two treatment periods. Units used the alternative strategy in the second period. Each treatment period lasted for the time taken for enrolment and study of 20 consecutive patients per intensive care unit; patients were monitored until discharge from the unit or for up to 30 days' mechanical ventilation, whichever was first. Units enrolled 967 patients, but 118 were excluded because they had been receiving mechanical ventilation for less than 2 days. The primary outcome measure was the mean number of chest radiographs per patient-day of mechanical ventilation. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00893672.

FINDINGS

11 intensive care units were randomly allocated to use a routine strategy to order chest radiographs in the first treatment period, and 10 units to use an on-demand strategy. Overall, 424 patients had 4607 routine chest radiographs (mean per patient-day of mechanical ventilation 1.09, 95% CI 1.05-1.14), and 425 had 3148 on-demand chest radiographs (mean 0.75, 0.67-0.83), which corresponded to a reduction of 32% (95% CI 25-38) with the on-demand strategy (p<0.0001).

INTERPRETATION

Our results strongly support adoption of an on-demand strategy in preference to a routine strategy to decrease use of chest radiographs in mechanically ventilated patients without a reduction in patients' quality of care or safety.

FUNDING

Assistance Publique-Hôpitaux de Paris (Direction Régionale de la Recherche Clinique Ile de France).

Chest radiograph evaluation and interpretation

Chest imaging is an important tool in managing critically ill patients. Basic chest radiology is still used to quickly detect abnormalities in the chest. Critical care nurses are often the ones who first read the radiologist's report of chest radiograph results and provide their interpretation to a physician. Oftentimes, chest radiographs are obtained routinely on a daily basis for every critical care patient, with the goal of effective clinical management. Critical care nurses can confirm cardiopulmonary assessment findings by also evaluating their patient's chest radiographs and reviewing the radiologist's report. By learning some basic skills in interpreting and evaluating chest radiographs, nurses can recognize and localize gross pathologic changes visible on a chest radiograph. This article provides basic chest radiograph interpretation information that allows readers to review relevant anatomy and physiology, summarize normal and abnormal findings on chest radiographs, and describe radiographic findings in common pulmonary and cardiac disorders.

Low Value of Routine Chest Radiographs in a Mixed Medical-Surgical ICU

OBJECTIVE

To determine the diagnostic efficacy (DE) and therapeutic efficacy (TE) of daily routine chest radiographs (CXRs), and to establish the impact of abandoning this CXR from daily practice on total CXR volume, ICU length of stay (LOS), readmission rate, and ICU mortality.

DESIGN

Prospective controlled study in two parts. The first part comprised a 1-year period during which attending physicians were blinded for findings on daily routine CXRs and were only informed if something deemed important was seen by the radiologist (predefined major abnormalities) who reviewed all CXRs as usual. The second part comprised a half-year period during which daily routine CXRs were replaced by clinically indicated CXR.

SETTING

Mixed medical-surgical ICU of a teaching hospital.

RESULTS

Data on 1,780 daily routine CXRs in 559 hospital admissions were collected. DE of daily routine CXRs was 4.4%. The most frequent unexpected major abnormalities were new or progressive infiltrates (1.8%) and oropharyngeal tube malposition (0.7%). TE of daily routine CXRs was 1.9%. The most frequent intervention was oropharyngeal tube adjustment (0.6%). No relation was found for DE or TE and hospital admission type or intubation and mechanical ventilation. In the second study part, 433 CXRs were obtained in 274 admissions. Abandoning daily routine CXRs did not affect clinically indicated CXRs orders, or ICU LOS, readmission rate, and mortality. A total CXR volume reduction of 35% (which equaled 9,900 per bed per year [US dollars]) was observed after abandoning daily routine CXRs.

CONCLUSION

Diagnostic and therapeutic value of the daily routine CXR is low. Daily routine CXRs can be safely abandoned in the ICU.

Chest radiography practice in critically ill patients: a postal survey in the Netherlands

Background

To ascertain current chest radiography practice in intensive care units (ICUs) in the Netherlands.

Methods

Postal survey: a questionnaire was sent to all ICUs with > 5 beds suitable for mechanical ventilation; pediatric ICUs were excluded. When an ICU performed daily-routine chest radiographs in any group of patients it was considered to be a "daily-routine chest radiography" ICU.

Results

From the number of ICUs responding, 63% practice a daily-routine strategy, in which chest radiographs are obtained on a daily basis without any specific reason. A daily-routine chest radiography strategy is practiced less frequently in university-affiliated ICUs (50%) as compared to other ICUs (68%), as well as in larger ICUs (> 20 beds, 50%) as compared to smaller ICUs (< 20 beds, 65%) (P > 0.05). Remarkably, physicians that practice a daily-routine strategy consider daily-routine radiographs helpful in guiding daily practice in less than 30% of all performed radiographs. Chest radiographs are considered essential for verification of the position of invasive devices (81%) and for diagnosing pneumothorax, pneumonia or acute respiratory distress syndrome (82%, 74% and 69%, respectively). On demand chest radiographs are obtained after introduction of thoracic drains, central venous lines and endotracheal tubes in 98%, 84% and 75% of responding ICUs, respectively. Chest films are also obtained in case of ventilatory deterioration (49% of responding ICUs), and after cardiopulmonary resuscitation (59%), tracheotomy (58%) and mini-tracheotomy (23%).

Conclusion

There is notable lack of consensus on chest radiography practice in the Netherlands. This survey suggests that a large number of intensivists may doubt the value of daily-routine chest radiography, but still practice a daily-routine strategy.

The clinical value of daily routine chest radiographs in a mixed medical-surgical intensive care unit is low

INTRODUCTION

The clinical value of daily routine chest radiographs (CXRs) in critically ill patients is unknown. We conducted this study to evaluate how frequently unexpected predefined major abnormalities are identified with daily routine CXRs, and how often these findings lead to a change in care for intensive care unit (ICU) patients.

METHOD

This was a prospective observational study conducted in a 28-bed, mixed medical-surgical ICU of a university hospital.

RESULTS

Over a 5-month period, 2,457 daily routine CXRs were done in 754 consecutive ICU patients. The majority of these CXRs did not reveal any new predefined major finding. In only 5.8% of daily routine CXRs (14.3% of patients) was one or more new and unexpected abnormality encountered, including large atelectases (24 times in 20 patients), large infiltrates (23 in 22), severe pulmonary congestion (29 in 25), severe pleural effusion (13 in 13), pneumothorax/pneumomediastinum (14 in 13), and malposition of the orotracheal tube (32 in 26). Fewer than half of the CXRs with a new and unexpected finding were ultimately clinically relevant; in only 2.2% of all daily routine CXRs (6.4% of patients) did these radiologic abnormalities result in a change to therapy. Subgroup analysis revealed no differences between medical and surgical patients with regard to the incidence of new and unexpected findings on daily routine CXRs and the effect of new and unexpected CXR findings on daily care.

CONCLUSION

In the ICU, daily routine CXRs seldom reveal unexpected, clinically relevant abnormalities, and they rarely prompt action. We propose that this diagnostic examination be abandoned in ICU patients.

Can we abandon daily routine chest radiography in intensive care patients?

Two different schools of thought exist on the utility of daily routine chest radiographs in intensive care unit (ICU) patients: some ICU physicians argue that daily routine chest radiographs are indicated in all patients who have cardiopulmonary problems or are receiving artificial ventilation. Others state that chest radiographs should be made on indication only, for example, following a change in clinical status or change of supportive devices. Most studies on this topic have simply reported the existence of several findings on chest radiographs; some investigators tried to determine whether such findings were new and/or unexpected and whether they caused a therapy change. A restrictive strategy has been compared with a daily routine strategy in only 2 clinical trials: 1 study conducted in a pediatric ICU (pediatric ICUs usually have low mortality rates), and the other a rather small (and probably underpowered) study. The debate about discontinuing daily routine chest radiographs in the ICU is still not settled.

Routine Daily Chest Radiography in Patients with Pulmonary Artery Catheters

• Background Pulmonary artery catheters are widely used invasive monitoring devices in critically ill patients. Clinicians disagree about whether daily chest radiographs are needed or clinical parameters alone are sufficient to verify catheter placement.

• Objectives To determine whether daily chest radiographs are needed to assess migration of pulmonary artery catheters.

• Methods One hundred consecutive patients with pulmonary artery catheters were prospectively evaluated. Clinical criteria for optimal position of the pulmonary artery catheters and findings on chest radiographs were compared. Optimal clinical criteria were (1) amount of air required to measure pulmonary capillary wedge pressure: 1.25 to 1.5 mL and (2) pulmonary artery catheter migrated 1 cm or less from initial position.

• Results Three hundred ninety comparisons of clinical criteria and radiographic findings were done. Chest radiographs indicated the catheter required repositioning in 15 (4%) of 390 instances but in only 4 (1%) of 310 instances in which bedside clinical findings indicated adequate catheter position. In 69 (18%) of the 390 cases, the clinical criteria for adequate catheter position were not met, but radiographs showed the catheter in an appropriate position. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of abnormal clinical criteria were 73%, 82%, 81%, 14%, and 99%, respectively.

• Conclusions Chest radiographs indicated that about 4% of catheters required repositioning. Catheter malposition can be reliably excluded (negative predictive value, 99%) by close observation of specific clinical criteria, so routine daily chest radiographs do not seem justified.

Routine chest radiographs in pediatric intensive care units

OBJECTIVES

To determine whether interventions were performed based on portable routine morning chest x-rays (CXRs) in pediatric intensive care unit (PICU) patients and to identify patient subgroups for whom the routine CXR is most useful.

DESIGN

Prospective multiinstitutional study. Setting. PICUs of 15 tertiary care hospitals. Patients. PICU patients who received a routine morning CXR were included in the study.

OUTCOME MEASURES

Recorded data included: weight, diagnosis, presence of active cardiopulmonary problems, length of stay, and number and type of devices. The number and types of interventions based on the interpretation of the CXR were recorded.

RESULTS

Five hundred twelve routine CXRs were evaluated. The majority of the routine chest radiographs were obtained on patients who were admitted for cardiovascular disease (195/512; 38%) or respiratory failure (186/512; 36%), and 465/512 of the routine CXRs (91%) were performed on patients with one or more devices. Two hundred thirty-one of the 512 routine CXRs (45%) resulted in 1 or more interventions. One hundred fifty-five of the 284 routine CXRs (55%) obtained in children </=10 kg resulted in one or more interventions, compared with 61/152 (40%) and 15/76 (20%) of routine CXRs obtained in children 10 to 40 kg and >/=40 kg, respectively. The frequency of interventions increased from 19% in children with no devices to >50% in children with 2 or more devices. One or more interventions were performed in 27% of routine CXRs when no active cardiopulmonary problems were present, compared with 51% of routine CXRs when active cardiopulmonary problems were present. Diagnosis and length of intensive care unit stay at the time the routine CXR was obtained did not affect the percentage of CXRs that resulted in interventions.

CONCLUSIONS

Routine CXRs are more likely to result in interventions in the smaller, critically ill child with one or more devices and if active cardiopulmonary problems are present.

Use of an optical fiber scope to confirm endotracheal tube placement in pediatric patients

OBJECTIVE

To determine the efficacy of a portable optical fiber scope to confirm endotracheal tube (ETT) placement.

DESIGN

A prospective, nonrandomized, blinded study.

SETTING

Pediatric intensive care unit in a children's hospital.

PATIENTS

Thirty mechanically ventilated patients with an ETT in place.

INTERVENTIONS

Patients entered into the study underwent ETT placement determination by chest roentgenogram (CXR) and by the optical fiber scope.

MEASUREMENTS AND MAIN RESULTS

Thirty patients were entered into the study, for a total of 46 measurements (n = 46). ETT size ranged from 3.0 to 6.0 mm internal diameter. Distance from the ETT and the carina was determined by the scope and compared with the distance measured on the CXR. No statistical difference was found between the two methods. None of the patients experienced clinically significant side effects from the procedure. On three occasions, the presence of secretions in the ETT did not allow for the visualization of the carina by the scope.

CONCLUSION

The use of a flexible optical fiber scope is an accurate, fast, and practical method to determine ETT placement in pediatric patients on mechanical ventilation.

Utility of routine chest radiographs in a medical-surgical intensive care unit: a quality assurance survey

OBJECTIVE

To determine the utility of routine chest radiographs (CXRs) in clinical decision-making in the intensive care unit (ICU).

DESIGN

A prospective evaluation of CXRs performed in the ICU for a period of 6 months. A questionnaire was completed for each CXR performed, addressing the indication for the radiograph, whether it changed the patient's management, and how it did so.

SETTING

A 14-bed medical-surgical ICU in a university-affiliated, tertiary care hospital.

PATIENTS

A total of 645 CXRs were analyzed in 97 medical patients and 205 CXRs were analyzed in 101 surgical patients.

RESULTS

Of the 645 CXRs performed in the medical patients, 127 (19.7%) led to one or more management changes. In the 66 surgical patients with an ICU stay <48 hours, 15.4% of routine CXRs changed management. In 35 surgical patients with an ICU stay > or = 48 hours, 26% of the 100 routine films changed management. In both the medical and surgical patients, the majority of changes were related to an adjustment of a medical device.

CONCLUSIONS

Routine CXRs have some value in guiding management decisions in the ICU. Daily CXRs may not, however, be necessary for all patients.

Ultrasound and other imaging technologies in the intensive care unit

As technology advances, more imaging and procedures are performed at the bedside on critically ill patients in ICUs, thereby eliminating the risks of transporting patients. These imaging techniques can serve as diagnostic and therapeutic tools in treating the acute and chronic consequences of injured, critically ill patients. One area of growth is ultrasonography. Critical care applications of ultrasonography are expanding, and the learning curve of surgeons and intensivists performing some of these studies is improving. Ultrasonography can supplement physical examination and provide useful "real-time" information on nearly every body cavity. Other imaging technology is also available in a portable form, enabling imaging directly at the bedside. Images are now becoming readily and easily available with the advancement of teleradiology. Some of the imaging modalities are still in development, and their clinical effectiveness is being studied. In the future, more uses of these various imaging technologies may become evident and cost-effective.

A picture archival and communication system shortens delays in obtaining radiographic information in a medical intensive care unit

OBJECTIVE

To assess whether variables such as unit occupancy and aggregate severity of illness that reflect increased work demands on physicians in medical intensive care units (MICU) are associated with increased delays in their obtaining information about nonroutine chest radiographic examinations. To determine whether the presence of a picture archiving and communication system (PACS) workstation in the MICU shortens those delays.

DESIGN

A prospective cohort study stratified for presence or absence of PACS.

SETTING

MICU of a university hospital.

PATIENTS

A total of 118 patients admitted to the MICU who had nonroutine bedside chest radiographs.

MEASUREMENTS AND MAIN RESULTS

Multivariate analyses were conducted to determine how unit occupancy, patient acuity, the time of day the examination was taken, and the presence of a PACS workstation influenced the time from radiographic examination completion to the time when MICU physicians first obtained image information. In a multivariate analysis, patient acuity, unit occupancy, the aggregate level of severity of illness in the study cohort, whether the examination was taken at night or day, and the presence of a PACS workstation were significant predictors of the elapsed time from examination completion until review by MICU physicians. Without the PACS workstation, higher occupancy, higher aggregate severity of illness, and examinations taken during the day were associated with longer delays. Overall, the multivariate analysis showed a 24-min decrease in the elapsed time to obtain information during periods with the PACS workstation compared with periods without the workstation (p = .03).

CONCLUSIONS

A PACS workstation significantly decreased the delays in obtaining image information that occurred with high unit occupancy and high aggregate severity of illness and may improve unit efficiency under conditions of high physician workload.

Financial impact of elimination of routine chest radiographs in a pediatric intensive care unit

OBJECTIVE

To determine the change in chest radiograph use if each chest radiograph requires a separate order and clinical indication.

DESIGN

Prospective, nonrandomized, controlled design with an intervention.

SETTING

The pediatric intensive care unit (PICU) at Primary Children's Medical Center, Salt Lake City, UT.

PATIENTS

The study comprised 3,727 PICU patients treated between 1992 and 1996.

INTERVENTIONS

A change in ordering practice: There will be no standing orders for routine daily morning chest radiographs. Each radiograph requires a written order and a clinical indication.

MEASUREMENTS AND MAIN RESULTS

During a 29-month control phase when routine daily chest radiographs were obtained for all intubated patients, 1.026 chest radiographs per patient day were performed. After the intervention, the ratio dropped to 0.653 chest radiographs per patient day, a decrease of 36.4%. This resulted in a (projected) variable cost savings of $45,476. Data were also collected for quality assurance purposes.

CONCLUSIONS

These results demonstrate the impact of an evaluation and subsequent change in radiology ordering practice in our PICU. The change resulted in decreased variability in ordering practice, fewer chest radiographs per patient, and an accompanying cost savings to our patients and payors.