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

Prognostic Value of the Radiographic Assessment of Lung Edema Score in Mechanically Ventilated ICU Patients

INTRODUCTION

The Radiographic Assessment of Lung Edema (RALE) score provides a semi-quantitative measure of pulmonary edema. In patients with acute respiratory distress syndrome (ARDS), the RALE score is associated with mortality. In mechanically ventilated patients in the intensive care unit (ICU) with respiratory failure not due to ARDS, a variable degree of lung edema is observed as well. We aimed to evaluate the prognostic value of RALE in mechanically ventilated ICU patients.

METHODS

Secondary analysis of patients enrolled in the 'Diagnosis of Acute Respiratory Distress Syndrome' (DARTS) project with an available chest X-ray (CXR) at baseline. Where present, additional CXRs at day 1 were analysed. The primary endpoint was 30-day mortality. Outcomes were also stratified for ARDS subgroups (no ARDS, non-COVID-ARDS and COVID-ARDS).

RESULTS

422 patients were included, of which 84 had an additional CXR the following day. Baseline RALE scores were not associated with 30-day mortality in the entire cohort (OR: 1.01, 95% CI: 0.98-1.03, p = 0.66), nor in subgroups of ARDS patients. Early changes in RALE score (baseline to day 1) were only associated with mortality in a subgroup of ARDS patients (OR: 1.21, 95% CI: 1.02-1.51, p = 0.04), after correcting for other known prognostic factors.

CONCLUSIONS

The prognostic value of the RALE score cannot be extended to mechanically ventilated ICU patients in general. Only in ARDS patients, early changes in RALE score were associated with mortality.

Evaluation of the Daily Change in PaO2/FiO2 Ratio as a Predictor of Abnormal Chest X-rays in Intensive Care Unit Patients Post Mechanical Ventilation Weaning: A Retrospective Cohort Study

Background and Objectives: The routine daily chest X-ray (CXR) strategy is no longer recommended in intensive care unit (ICU) patients. However, it is difficult for intensivists to collectively accept the on-demand CXR strategy because of the ambiguous clinical criteria for conducting CXRs. This study evaluated the predictive value of the change in PaO₂/FiO₂ (PF ratio) for abnormal CXR findings in ICU patients after mechanical ventilation (MV). Materials and Methods: A retrospective cohort study was conducted between January 2016 and March 2021 on ICU patients with MV who had at least 48 h of MV, and stayed at least 72 h in the ICU post-MV. Routine daily CXRs and daily changes in the PF ratios were investigated during the three days post-MV. Results: The 186 patients included in the study had a median age of 77 years (interquartile range: 65–82), and 116 (62.4%) were men. One hundred and eight (58.1%) patients had abnormal CXR findings, defined as one or more abnormal CXRs among the daily CXRs during the three days post-extubation. The reintubation rate was higher in the abnormal CXR group (p = 0.01). Of the 558 CXRs (normal = 418, abnormal = 140) and PF ratios, the daily change in PF ratio had a significant predictive accuracy for abnormal CXR findings (AUROC = 0.741, p < 0.01). Conclusions: The change in PF ratio (the Youden index point: ≤−23) had a sensitivity of 65.7%, and a specificity of 79.9%. Based on these results, the daily change in the PF ratio could be utilized as a predictive indicator of abnormal CXRs in ICU patients after MV treatment.

The Prognostic Capacity of the Radiographic Assessment for Lung Edema Score in Patients With COVID-19 Acute Respiratory Distress Syndrome-An International Multicenter Observational Study

Background: The radiographic assessment for lung edema (RALE) score has an association with mortality in patients with acute respiratory distress syndrome (ARDS). It is uncertain whether the RALE scores at the start of invasive ventilation or changes thereof in the next days have prognostic capacities in patients with COVID-19 ARDS.

Aims and Objectives: To determine the prognostic capacity of the RALE score for mortality and duration of invasive ventilation in patients with COVID-19 ARDS.

Methods: An international multicenter observational study included consecutive patients from 6 ICUs. Trained observers scored the first available chest X-ray (CXR) obtained within 48 h after the start of invasive ventilation (“baseline CXR”) and each CXRs thereafter up to day 14 (“follow-up CXR”). The primary endpoint was mortality at day 90. The secondary endpoint was the number of days free from the ventilator and alive at day 28 (VFD-28).

Results: A total of 350 CXRs were scored in 139 patients with COVID-19 ARDS. The RALE score of the baseline CXR was high and was not different between survivors and non-survivors (33 [24–38] vs. 30 [25–38], P = 0.602). The RALE score of the baseline CXR had no association with mortality (hazard ratio [HR], 1.24 [95% CI 0.88–1.76]; P = 0.222; area under the receiver operating characteristic curve (AUROC) 0.50 [0.40–0.60]). A change in the RALE score over the first 14 days of invasive ventilation, however, had an independent association with mortality (HR, 1.03 [95% CI 1.01–1.05]; P < 0.001). When the event of death was considered, there was no significant association between the RALE score of the baseline CXR and the probability of being liberated from the ventilator (HR 1.02 [95% CI 0.99–1.04]; P = 0.08).

Conclusion: In this cohort of patients with COVID-19 ARDS, with high RALE scores of the baseline CXR, the RALE score of the baseline CXR had no prognostic capacity, but an increase in the RALE score in the next days had an association with higher mortality.

Accuracy of the Radiographic Assessment of Lung Edema Score for the Diagnosis of ARDS

Background: Bilateral opacities on chest radiographs are part of the Berlin Definition for Acute Respiratory Distress Syndrome (ARDS) but have poor interobserver reliability. The “Radiographic Assessment of Lung Edema” (RALE) score was recently proposed for evaluation of the extent and density of alveolar opacities on chest radiographs of ARDS patients. The current study determined the accuracy of the RALE score for the diagnosis and the prognosis of ARDS.

Methods:Post-hoc analysis of a cohort of invasively ventilated intensive care unit (ICU) patients expected to need invasive ventilation for >24 h. The Berlin Definition was used as the gold standard. The RALE score was calculated for the first available chest radiograph after start of ventilation in the ICU. The primary endpoint was the diagnostic accuracy for ARDS of the RALE score. Secondary endpoints included the prognostic value of the RALE score for ICU and hospital mortality, and the association with ARDS severity, and the PaO₂/FiO₂. Receiver operating characteristic (ROC) curves were constructed, and the optimal cutoff was used to determine sensitivity, specificity and the negative and positive predictive value of the RALE score for ARDS.

Results: The study included 131 patients, of whom 30 had ARDS (11 mild, 15 moderate, and 4 severe ARDS). The first available chest radiograph was obtained median 0 [0 to 1] days after start of invasive ventilation in ICU. Compared to patients without ARDS, a higher RALE score was found in patients with ARDS (24 [interquartile range (IQR) 16–30] vs. 6 [IQR 3–11]; P < 0.001), with RALE scores of 20 [IQR 14–24], 26 [IQR 16–32], and 32 [IQR 19–36] for mild, moderate and severe ARDS, respectively, (P = 0.166). The area under the ROC for ARDS was excellent (0.91 [0.86–0.96]). The best cutoff for ARDS diagnosis was 10 with 100% sensitivity, 71% specificity, 51% positive predictive value and 100% negative predictive value. The RALE score was not associated with ICU or hospital mortality, and weakly correlated with the PaO₂/FiO₂.

Conclusion: In this cohort of invasively ventilated ICU patients, the RALE score had excellent diagnostic accuracy for ARDS.

Prescription practice and clinical utility of chest radiographs in a pediatric intensive care unit: a prospective observational study

Background

Chest radiograph (CXR) prescribing pattern and practice vary widely among pediatric intensive care units (PICU). ‘On demand’ approach is increasingly recommended as against daily ‘routine’ CXRs; however, the real-world practice is largely unknown.

Methods

This was a prospective observational study performed in children younger than 12 years admitted to PICU of a tertiary care teaching hospital in India. Data were collected on all consecutive CXRs performed between December 2016 and April 2017. The primary outcome was to assess the factors that were associated with higher chest radiograph prescriptions in PICU. Secondary outcomes were to study the indications, association with mechanical ventilation, image quality and avoidable radiation exposure.

Results

Of 303 children admitted during the study period, 159 underwent a total of 524 CXRs in PICU. Median (IQR) age of the study cohort was 2 (0.6–5) years. More than two thirds [n = 115, 72.3%] were mechanically ventilated. Most CXRs (n = 449, 85.7%) were performed on mechanically ventilated patients, amounting to a median (IQR) of 3 (2–5) radiographs per ventilated patient. With increasing duration of ventilation, the number of CXRs proportionately increased in the first two weeks of mechanical ventilation. In non-ventilated children, about two thirds (68%) underwent only one CXR. Majority of the prescriptions were on demand (n = 461, 88%). Most common indications were peri-procedure prescriptions (37%) followed by evaluation for respiratory disease status (24%). About 40% CXRs resulted in interventions; adjustment in ventilator settings (13.5%) was the most frequent intervention. In 26% (n = 138) of radiographs, image quality required improvement. One or more additional body part exposure other than chest and upper abdomen were noted 336 (64%) images. Children with > 3 CXR had higher PRISM III score, more often mechanically ventilated, had higher number of indwelling devices [mean (SD) 2.6 (1.2) vs. 1.7 (1.0)] and stayed longer in PICU [median (IQR) 11(7.5–18.5) vs. 6 (3–9)].

Conclusion

On demand prescription was the prevalent practice in our PICU. Most non-ventilated children underwent only one CXR while duration of PICU stay and the number of devices determined the number of CXRs in mechanically ventilated children. Quality improvement strategies should concentrate on the process of acquisition of images and limiting the radiation exposure to unwanted body parts.

Reducing chest radiography utilization in the medical intensive care unit

BACKGROUND AND PURPOSE

Daily chest radiographs (CXRs) have long been a routine part of care. However, evidence as well as changing technology has promoted on-demand CXRs as beneficial to patient care. We found that a substantial number of routine daily CXRs were being ordered, with some of the orders staying active even after extubation.

METHODS

Within a 19-bed adult medical ICU, we prospectively utilized 3 intervention phases from October 1, 2014, to February 28, 2018, to reduce routine CXRs. Nurse Practitioners (NP) initiated this quality improvement (QI) project, aiming to reduce the number of unnecessary of CXRs. Interventions included staff survey, routine CXR order removal, duplicate alerts, visual reminders, and an electronic clinical decision support tool. Monthly education of appropriate CXRs and bedside ultrasound were facilitated by NPs. The outcome measures of interest include: the number of CXRs per patient-day, the number of routine and on-demand CXRs, mortality rate, ICU length of stay, and ventilator days, radiation and cost.

CONCLUSIONS

Total number of CXRs per patient-day decreased by 36.1%. The proportion of routine CXRs decreased from 55.37% to 13.18%; on-demand orders increased, from 44.63% to 86.82%; and calculated radiation-exposure per census decreased, from 0.011 to 0.008 mSv. In addition, charges to patients for CXRs decreased by $7,750/month. ICU mortality and ventilator days per census remained stable.

IMPLICATIONS FOR PRACTICE

By an orchestrated process that included creating awareness and desire to change CXR ordering practices, we were able to decrease routine CXRs and increase on-demand utilization while maintaining counterbalance measures.

Accuracy of Conventional and Machine Learning Enhanced Chest Radiography for the Assessment of COVID-19 Pneumonia: Intra-Individual Comparison with CT

PURPOSE

To evaluate diagnostic accuracy of conventional radiography (CXR) and machine learning enhanced CXR (mlCXR) for the detection and quantification of disease-extent in COVID-19 patients compared to chest-CT.

METHODS

Real-time polymerase chain reaction (rt-PCR)-confirmed COVID-19-patients undergoing CXR from March to April 2020 together with COVID-19 negative patients as control group were retrospectively included. Two independent readers assessed CXR and mlCXR images for presence, disease extent and type (consolidation vs. ground-glass opacities (GGOs) of COVID-19-pneumonia. Further, readers had to assign confidence levels to their diagnosis. CT obtained ≤ 36 h from acquisition of CXR served as standard of reference. Inter-reader agreement, sensitivity for detection and disease extent of COVID-19-pneumonia compared to CT was calculated. McNemar test was used to test for significant differences.

RESULTS

Sixty patients (21 females; median age 61 years, range 38-81 years) were included. Inter-reader agreement improved from good to excellent when mlCXR instead of CXR was used (k = 0.831 vs. k = 0.742). Sensitivity for pneumonia detection improved from 79.5% to 92.3%, however, on the cost of specificity 100% vs. 71.4% (p = 0.031). Overall, sensitivity for the detection of consolidation was higher than for GGO (37.5% vs. 70.4%; respectively). No differences could be found in disease extent estimation between mlCXR and CXR, even though the detection of GGO could be improved. Diagnostic confidence was better on mlCXR compared to CXR (p = 0.013).

CONCLUSION

In line with the current literature, the sensitivity for detection and quantification of COVID-19-pneumonia was moderate with CXR and could be improved when mlCXR was used for image interpretation.

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.

Daily routine versus on-demand chest radiograph policy and practice in adult ICU patients- clinicians' perspective

Background

Chest radiographs are taken daily as a part of routine investigations in Intensive care unit (ICU) patients. They are less effective and unlikely to alter the management of the majority of these patients compared to the radiographs obtained when indicated. According to the American College of Radiology (ACR) Appropriateness criteria, only selective ordering of chest radiographs is recommended, including elderly or high risk patients. The aim of this study was to identify and assess the clinician’s perspective in abandoning the current practice of daily routine chest radiograph and replacing with the on-demand radiograph in Saudi hospitals.

Methods

This was a cross-sectional study. A valid self-administered questionnaire was distributed to all clinical staff members working in ICUs in the major tertiary hospitals in Saudi Arabia. The study population was primarily the ICU intensivists (physicians), nurses and respiratory therapists (RT). The data collected were statistically processed using SPSS version 20.0; descriptive and inferential analyses were done.

Results

Out of 730 questionnaires sent, we received only 495 completed questionnaires with a response rate of 67.8%. Majority of them (n = 351) are working at academic hospitals. About half of the respondents (n = 247) are working in an open-format ICUs. Findings showed that the daily routine chest X-ray was performed in almost 96.8% of ICUs patients, which the majority of the clinical staff members (73%) thought that this current daily routine CXR protocol in the ICUs should be replaced with the on-demand CXR policy. Interestingly, the differences in demographic and work-related characteristics had no significant impact on the clinician’s view and supported moving to on-demand CXR policy and practice.

Conclusions

The daily routine CXR is still a common practice in most of the Saudi hospitals ICUs although enough empirical evidence shows that it can be avoided. We observed that intensivists support the change of the current practice and recommend an on-demand CXR policy likely to be followed in intensive care management.

Electronic supplementary material

The online version of this article (10.1186/s12880-018-0248-6) contains supplementary material, which is available to authorized users.

Inappropriateness of diagnostic imaging examinations in the inpatient setting: a case study research

OBJECTIVE

The purpose of our study was to audit the clinical appropriateness of the prescriptions of whole body CT (WB-CT), PET-CT and chest X-rays (CXRs) performed at Tor Vergata University Hospital in the inpatient setting.

MATERIALS AND METHODS

WB-CT, PET-CT and CXRs examinations were retrospectively analysed in the period between January and December 2014. CXR examinations were divided into bedside CXRs and traditional CXRs. The appropriateness of the examinations was defined according the American College of Radiology Appropriateness Criteria. Inappropriate examinations were divided into six inappropriateness categories in accordance with the European Union Medical Imaging Guidelines.

RESULTS

Appropriateness was suboptimal for all analysed techniques CXRs (A = 38%, I = 62%); bedside CXRs (A = 45%, I = 53%); WB-CT (A = 45%, I = 55%); PET-CT (A = 48%, I = 52%). With respect to WB-CT the highest rate of inappropriate imaging prescriptions came from the haematology clinical operative unit (OU) (44%) and emergency medicine (33%); with respect to PET-CT, the thoracic surgery OU (53%) and haematology OU (48%) showed the most inappropriate prescriptions. For CXRs, the percentage of inappropriateness was consistently distributed among all surgical OUs. For bedside CXRs, the largest inappropriate prescribers were the emergency medicine OU (48%), the cardiac surgery OU (58%), the intensive care OU (67%) and anaesthesia resuscitation OU (78%). The most represented classes of inappropriateness were 2, 3, 4 and 6.

CONCLUSIONS

The elimination of inappropriate prescriptions would result in an annual savings of approximately 390,000 Euro. An implementation plan to increase prescription appropriateness is under development by our group.

Patient and staff dosimetry during radiographic procedures in an intensive care unit

The performance of radiography in the Intensive Care Unit (ICU) may be associated with a certain level of radiation exposure for staff and patients in the unit. Little evidence on exposure levels is available in the literature. However, healthcare professionals in the ICUs at our centre tend to leave the room during radiographic examinations, potentially compromising patient care. The objectives of this study were to quantify dose levels within the ICU and to evaluate the performance of ICU x-ray studies according to patient dose measurements. This study was conducted in the 18-bed ICU of a third-level hospital. The scattering radiation due to mobile x-ray examinations was measured by using four personal thermoluminiscent dosimeters (TLDs). The dose area product (DAP) was measured at each examination using a transmission chamber installed on the diaphragm of the x-ray equipment. Based on the TLD readings and taking account of the error margin, the annual dose to patients and staff was less than 0.6 mSv. The value given by the DAP meter for chest x-rays was 94  ±  17 mGy cm(2); this value is well below the lower limit recommended by different agencies and committees. Exposure levels were found to be extremely low and pose no apparent risk to staff or to those in beds adjacent to the patients undergoing x-ray examinations, which were correctly performed in the unit.

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.

Chest radiographs in 104 French ICUs: current prescription strategies and clinical value (the RadioDay study)

OBJECTIVE

To analyze the current practices of chest radiograph (CXR) prescription and their clinical impact.

DESIGN

Prospective snapshot observational study (on RadioDay) combined with a survey.

PATIENTS

Patients who were given a CXR on RadioDay.

SETTING

One hundred four French intensive care units (ICUs).

RESULTS

On RadioDay, 854 CXRs (in 804 patients) were ordered. For the "CXRs morning round," the prescription policy was declared to be "on-demand" (in 63 % of the ICUs), "daily routine only in mechanically ventilated patients (MV)" (30 %) or, less frequently, "daily routine in all patients" (7 %). When analyzing the two main local policies, as compared with "daily routine only in MV" ICUs, in "on-demand" ICUs: (1) fewer CXRs were ordered (0.6 ± 0.3 vs. 0.9 ± 0.2 CXRs/patient, p < 0.001) with no increase in the rate of unscheduled CXRs (i.e., CXRs performed outside the morning round), and (2) individual CXRs were more often followed by a therapeutic intervention (which would not have occurred without the CXR): 34 vs. 25 % of the CXRs (p < 0.05). Last, in case of severe respiratory disease (low PaO(2)/FiO(2) ratio), it is noteworthy that the clinical value of "on-demand" individual CXRs was still markedly higher than that of "daily routine" CXRs.

CONCLUSION

Nearly two-thirds of the participating ICUs adopted the "on-demand" strategy of prescription, which was associated with a lower rate of CXRs with no increase in unscheduled CXRs and was of higher clinical value than a "daily routine in MV" strategy. Importantly, the study design did not allow assessing if the "on-demand" strategy had missed or delayed some diagnoses.

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.

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).

Thoracic imaging in the ICU

Imaging in the ICU plays a crucial role in patient care. The portable chest radiograph (CXR) is the most commonly requested radiographic examination, and, despite its limitations, it often reveals abnormalities that may not be detected clinically. Recent advances in CT technology have made it possible to obtain diagnostic-quality images even in the most dyspneic patient. This article reviews the significant contribution thoracic imaging makes in diagnosing and managing critically ill patients.

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.

Elimination of daily routine chest radiographs does not change on-demand radiography practice in post–cardiothoracic surgery patients

OBJECTIVE

We sought to determine the effect of elimination of daily routine chest radiographs on chest radiographic practice in cardiothoracic surgery patients in the intensive care unit and the post-intensive care unit ward.

METHODS

We used a prospective, comparative study design with an intervention in a 28-bed intensive care unit/post-intensive care unit ward (including a 4-bed medium-care unit) in a university hospital. Cardiothoracic surgery patients were admitted to the intensive care unit during a period of 6 months (3 months before intervention and 3 months after intervention). Daily routine chest radiographs in the intensive care unit were eliminated; all chest radiographs required a clinical indication. Routine chest radiographs were not performed in the post-intensive care unit ward, both before and after the intervention.

RESULTS

Before intervention, in the intensive care unit 353 daily routine chest radiographs and 261 on-demand chest radiographs were obtained in 175 patients; after intervention, 275 on-demand chest radiographs were obtained in 163 patients. Before intervention, in the post-intensive care unit ward 413 on-demand chest radiographs were obtained in 167 patients; after intervention, 445 on-demand chest radiographs were obtained in 161 patients. In the intensive care unit the number of chest radiographs per patient day decreased from 1.8 +/- 0.6 to 1.1 +/- 0.6. In the post-intensive care unit ward the number of chest radiographs per patient per day was 0.4 +/- 0.2, both before and after the intervention. Slightly more unexpected abnormalities were found in the on-demand chest radiographs after the intervention. No negative influence on chest radiography timing, length of stay in the intensive care unit and hospital, and readmission rate was seen.

CONCLUSIONS

Elimination of daily routine chest radiographs led to a decrease of the total number of chest radiographs obtained per patient per day in the intensive care unit and did not change chest radiography practice in the post-intensive care unit ward.

Year in review 2006: Critical Care--Resource management

As health care resources become increasingly constrained, it is imperative that intensive care unit resources be optimized. In the years to come, a number of challenges to intensive care medicine will need to be addressed as society changes. Last year's Critical Care papers provided us with a number of interesting and highly accessed original papers dealing with health care resources. The information yielded by these studies can help us to deal with issues such as prognostication, early detection and treatment of delirium, prevention of medical errors and use of radiology resources in critically ill patients. Finally, several aspects of scientific research in critically ill patients were investigated, focusing on the possibility of obtaining informed consent and recall of having given informed consent.