Introduction 1 2 3 4 5 While it can be recommended to discontinue a daily routine CXR practice in ICU patients, elimination of these CXRs may have several disadvantages. Firstly, eliminating daily routine CXRs bears the risk that the number of on demand CXRs increases. In addition, elimination of daily routine CXRs might result in on demand CXRs being obtained more frequently during off-time hours, which may cause an inverse rise of costs. Secondly, length of stay (LOS) in ICU, readmission rate and mortality rate might be negatively influenced by this change in CXR practice. To evaluate the impact of elimination of daily routine CXRs we determined the change in on demand CXR practice in our multidisciplinary ICU, where a daily routine CXR strategy was applied until performance of this study. In addition, we evaluated the diagnostic and therapeutic value of on demand CXRs before and after this intervention. Finally, LOS in ICU, readmission rate, and mortality rate during a daily routine CXR strategy were compared with those during an on demand CXR strategy. Materials and Methods Subjects A prospective, nonrandomized, controlled design with an intervention was used for this study. Of all patients, all CXRs taken in the adult ICU department of the Academic Medical Center in Amsterdam, Netherlands, from 1 March 2004 to 31 July 2004 and from 1 September 2004 to 31 January 2005 were studied. This department is a closed-format tertiary care, referral, 28-bed multidisciplinary ICU. The patient population consists of cardiothoracic surgery patients, medical patients (including cardiology patients and pulmonary disease patients), and surgery patients (including trauma patients and neurosurgery patients). Patients who were admitted during the period in between phases 1 and 2, as well as patients that were readmitted, were not analyzed. The study protocol was approved by the local ethics committee. Protocol The study period was divided into two parts: phase 1, a 5-month phase before the intervention during which the daily routine CXR strategy was practiced; and phase 2, a 5-month phase which began 1 month after the intervention. The intervention consisted of a change in the ordering practice of CXRs: no standing orders for daily routine CXRs; each (on demand) CXR required a clinical indication, such as admittance to the ICU, insertion of central venous lines, intra-aortic balloon pump or tracheal and chest tubes, an increase in oxygen requirement, or a change in pulmonary secretions with or without fever (see Table E1). 6 Diagnostic and therapeutic value of on demand CXR 5 If a predefined finding was unexpectedly found, then we determined whether any action was taken because of the new unexpected finding. To do this, two of us (M.G. and M.J.S.) and two independent observers carefully read the medical records, checked the patient data management system (Metavision, iMDsoft, Sassenheim, The Netherlands) and searched the hospital information system for the following: orders for sputum cultures or performance of a bronchoalveolar lavage for culture, or start of, or a change in, antimicrobial therapy in case of unexpected infiltrates on the CXR; repositioning of tubes in case of malposition of orotracheal tubes (ignoring planned extubations); ultrasound of the thorax in case of pleural effusion on the CXR, start or change in medication (diuretics); insertion of a pleural drain; and repositioning of devices in the case of malposition of medical devices other than orotracheal tubes (ignoring planned changes such as removal of intravenous lines). The observers were not involved in the daily care of the patients, and ICU physicians were not aware of this part of the observation. As a consequence, the clinical relevance of the predefined abnormalities could not be evaluated in some cases, specifically in cases of large atelectasis and severe pulmonary congestion, since start of physiotherapy, changes in levels of positive end-expiratory pressure, and the use of diuretics might have been triggered by other (clinical) findings. Statistical analysis p Results Study population 1 Table 1 APACHE-II CXRs CI  Phase 1 Phase 2 p No. of patients  754  622  Age (years; mean, SD)  60 (16)  62 (16) 0.02 n  475 (63%)  398 (64%) 0.70 n a 3194 (82%) 1115 (88%) < 0.001 APACHE-II score  16.4 ± 6.9  16.4 ± 7.2 1.00 Patient subgroups    n  317 (42%)  306 (49%) 0.01 n  197 (26%)  119 (19%)  n  144 (19%)  131 (21%)  n  69 (9%)  46 (7%)  n  27 (4%)  20 (3%)  Length of stay in ICU (days; median IQR)   1.9 (1.0–4.6)   1.9 (0.9–4.6) 0.95 Mortality    n  94 (12%)  62 (10%) 0.49 n  132 (18%)  104 (17%) 0.70  Predicted hospital mortality (%)  181 (24%)  155 (25%) 0.69  Observed/predicted ratio (95% CI)   0.73 (0.59–0.90)   0.67 (0.53–0.83)  a Utility of CXRs p 1 p Fig. 1 Open bars: closed symbols:  Diagnostic and therapeutic value of on demand CXRs 2 3 p p p p Table 2 Expected and unexpected findings on on demand chest radiographs  n n Abnormalities Expected Expected+found Unexpected+found Expected Expected+found Unexpected+found Large atelectasis  37 (2.6)  2 (0.1)  13 (0.9)  49 (3.9)  3 (0.2)  15 (1.2) Large infiltrates  57 (4.0)  3 (0.2)  21 (1.5)  69 (5.4)  5 (0.4)  27 (2.1) Pulmonary congestion  98 (6.8)  8 (0.6)  25 (1.7) 104 (8.2) 14 (1.1)  22 (1.7) Pleural effusion  41 (2.9)  3 (0.2)  17 (1.2)  43 (3.4)  4 (0.3)  27 (2.1) Pneumothorax or pneumomediastinum  68 (4.7)  4 (0.3)  17 (1.2) c  3 (0.2)  12 (0.9) Malposition of invasive devices 350 (24.4) 18 (1.3)  54 (3.8) c c  52 (4.1) Total no. of abnormalities 651 38 147 696 c 155 a 641 (44.6) 38 (2.6) 133 (9.2) c c c b 580 (76.9) 37 (4.9) 120 (15.9) c c 119 (19.1) Numbers in parentheses are percentages a b c p Table 3 ND  n n Abnormalities Resulting in a change in therapy Resulting in a change in therapy Large atelectasis ND ND Large infiltrates 10 (0.7%) 14 (1.1%) Pulmonary congestion ND ND Pleural effusion 11 (0.8%) 12 (0.9%) Pneumothorax or pneumomediastinum 11 (0.8%)  9 (0.7%) Malposition of invasive devices 25 (1.7%) 29 (2.3%) Total no. of abnormalities 57 64 a 56 (3.9%) 61 (4.8%) b 48 (6.4%) c a b c p LOS in ICU, readmission rate and mortality rate 1 P 1 Discussion The present study demonstrates the impact of elimination of daily routine CXRs in a mixed medical–surgical ICU. We found a sharp decline in the total number of CXRs, while only a minimal increase in the number of on demand CXRs was observed. In addition, the number of CXRs in off-hours was similar between the two periods. Elimination of daily routine CXRs did neither affect LOS in ICU and readmission rate nor ICU and hospital mortality rate. Although the diagnostic and therapeutic value of on demand CXRs was significantly higher after the intervention, we considered this difference clinically irrelevant. When one considers the increase in diagnostic and therapeutic value of on demand CXRs after elimination of daily routine CXRs indirect proof of the “value” of daily routine CXRs, one must also recognize its futility regarding the therapeutic value. Indeed, the percentage of CXRs with unexpected findings that truly led to a change in therapy was similar in the two study phases. Since readmission rate and mortality rate remained unchanged after the intervention, we conclude that the true value of daily routine CXRs in our multidisciplinary ICU is very low. Interestingly, only in medical patients did the number of CXRs that showed an unexpected predefined major abnormality increase after elimination of daily routine CXRs. The reason for this finding remains unexplained. The distribution of abnormalities encountered on CXRs of these patients was similar in the two study phases; however, neither readmission rate nor differences in raw or risk-adjusted ICU and hospital mortality rates of medical patients was affected by the change in CXR practice. One interesting finding was the decrease in abnormalities presumed to be present on CXRs. Indeed, a 30% reduction in expected predefined findings was observed in phase 2. This finding remains unexplained and we can only speculate on its cause. Firstly, it may be that physicians learned from experience that many of their expectations proved to be untrue during the actual carrying out of the study. This may have caused them to be more reluctant in scoring for expected findings. Alternatively, physicians may have become less enthusiastic about the study, which might have resulted in failure to comply with study rules at some moments (i.e., they did not fill in the back of the formal CXR request form); however, there was no change in expectations of physicians regarding abnormalities that truly led to a change in therapy. More importantly, if the backside of the formal forms were not filled out, as a rule the CXR was simply not obtained. Indeed, collection of data was complete regarding this issue, there were no on demand CXRs without a completed form. 7 8 7 8 5 Several important drawbacks of our study must be mentioned. Firstly, our study did not include a strict method for tracking complications as a result of elimination of daily routine CXRs. Indeed, several abnormalities might have been missed (or discovered too late) which might (or do) have impact on clinical outcome. Examples of these types of abnormalities include pneumothorax causing weaning problems, the malposition of devices such as central venous lines, causing extravasation of fluid, or orotracheal tubes, potentially causing injury to the vocal cords. Considering these examples, such a strict method may mandate a daily check of all invasive devices. Although possible complications of elimination of daily routine CXRs could be discussed in daily bedside rounds, daily radiology conferences and daily multidisciplinary meetings during the performance of our study, no clinically important complications were reported as the result of elimination of daily routine CXRs; thus, although we assume that the elimination of daily routine CXRs does not cause any complications, we cannot be certain that this was truly the case. Secondly, as mentioned previously, it is of importance to realize that results that come from one center may simply not be similar for other centers: differences in staffing; especially during off-hours, and differences in case mix may be of great influence on outcome when abandoning daily routine CXRs. Thirdly, as mentioned previously, we found a reduction in expected predefined finding in phase 2. We assumed that the cause of this reduction might be that the physicians became less enthusiastic about the study, which might be seen as a limitation of the study. Conclusion In conclusion, in our mixed medical–surgical ICU elimination of daily routine CXRs leads to a sharp decline in the total number of CXRs, while only minimally increasing the number of on demand CXRs. Although we cannot be certain whether we missed important findings by abandoning daily routine CXRs, its elimination did neither affect LOS in ICU, nor readmission rate and ICU and hospital mortality rates. Electronic supplementary material Electronic Supplementary Material (DOC 165K)