Portable Chest Radiographs Research Articles

Determination of intravascular volume status in critically ill patients using portable chest X-rays: measurement of the vascular pedicle width

Background and Aims: Traditionally, invasive hemodynamic pressure measurements have been used to assess the volume status in critically ill patients. The vascular pedicle, as seen on chest radiographs, is the mediastinal silhouette of the great vessels. It is measured by drawing a perpendicular line from the point at which the left subclavian artery emerges from the aortic arch and measured across to the point at which the superior vena cava crosses the right main stem bronchus. We carried out this study to establish a correlation between the width of the vascular pedicle as seen on chest radiographs and daily fluid balance or pulmonary capillary occlusion pressure in mechanically ventilated, critically ill patients. Materials and Methods: In this prospective clinical study, 50 consecutive adult patients in a tertiary care, multidisciplinary intensive care unit underwent simultaneous measurements of the width of the vascular pedicle as seen on standardized, portable chest radiographs in the supine position and pulmonary capillary occlusion pressure measurements. Twenty-four hour fluid balance calculations were also recorded for each patient. Results: Vascular pedicle width measurements correlated closely with positive fluid balance, r = + 0.88, P 0.000. A Receiver Operating Characteristic curve demonstrated that a vascular pedicle width of 86.5 mm had a 100% sensitivity and an 80% specificity (area under the curve 0.823, 95% confidence intervals 0.714-0.932) for predicting fluid overload equal to and greater than 1200 ml. The correlation between pulmonary capillary occlusion pressures and width of the vascular pedicle was poor, r = 0.41, P 0.02. Conclusions: Our findings suggest that the vascular pedicle width on daily chest radiographs can be used to assess hypervolemia in the intensive care unit. Serial changes in the pedicle width could possibly be used to increase the accuracy of predictions.

UTILITY OF PORTABLE CHEST RADIOGRAPH MEASUREMENTS IN DIFFERENTIATING CONGESTIVE HEART FAILURE FROM OTHER CAUSES OF DYSPNEA IN PATIENTS PRESENTING TO EMERGENCY ROOM

PURPOSE: To determine if vascular pedicle width (VPW), vascular pedicle ratio (VPR), or cardiothoracic ratio (CTR) on portable chest radiographs (CXR), accurately differentiate congestive heart failure (CHF) from others causes of dyspnea, and if any of these measurements have any additive value to serum B-type natriuretic peptide (BNP) levels.

Effect of a Clinical Pathway to Reduce Hospitalizations in Nursing Home Residents With Pneumonia

Nursing home residents with pneumonia are frequently hospitalized. Such transfers may be associated with multiple hazards of hospitalization as well as economic costs. To assess whether using a clinical pathway for on-site treatment of pneumonia and other lower respiratory tract infections in nursing homes could reduce hospital admissions, related complications, and costs. A cluster randomized controlled trial of 680 residents aged 65 years or older in 22 nursing homes in Hamilton, Ontario, Canada. Nursing homes began enrollment between January 2, 2001, and April 18, 2002, with the last resident follow-up occurring July 4, 2005. Residents were eligible if they met a standardized definition of lower respiratory tract infection. Treatment in nursing homes according to a clinical pathway, which included use of oral antimicrobials, portable chest radiographs, oxygen saturation monitoring, rehydration, and close monitoring by a research nurse, or usual care. Hospital admissions, length of hospital stay, mortality, health-related quality of life, functional status, and cost. Thirty-four (10%) of 327 residents in the clinical pathway group were hospitalized compared with 76 (22%) of 353 residents in the usual care group. Adjusting for clustering of residents in nursing homes, the weighted mean reduction in hospitalizations was 12% (95% confidence interval [CI], 5%-18%; P = .001). The mean number of hospital days per resident was 0.79 in the clinical pathway group vs 1.74 in the usual care group, with a weighted mean difference of 0.95 days per resident (95% CI, 0.34-1.55 days; P = .004). The mortality rate was 8% (24 deaths) in the clinical pathway group vs 9% (32 deaths) in the usual care group, with a weighted mean difference of 2.9% (95% CI, -2.0% to 7.9%; P = .23). There were no significant differences between the groups in health-related quality of life or functional status. The clinical pathway resulted in an overall cost savings of US 1016 dollars per resident (95% CI, 207 dollars-1824 dollars) treated. Treating residents of nursing homes with pneumonia and other lower respiratory tract infections with a clinical pathway can result in comparable clinical outcomes, while reducing hospitalizations and health care costs. clinicaltrials.gov Identifier: NCT00157612.

Rapid detection of pneumothorax by ultrasonography in patients with multiple trauma

IntroductionEarly detection of pneumothorax in multiple trauma patients is critically important. It can be argued that the efficacy of ultrasonography (US) for detection of pneumothorax is enhanced if it is performed and interpreted directly by the clinician in charge of the patients. The aim of this study was to assess the ability of emergency department clinicians to perform bedside US to detect and assess the size of the pneumothorax in patients with multiple trauma.MethodsOver a 14 month period, patients with multiple trauma treated in the emergency department were enrolled in this prospective study. Bedside US was performed by emergency department clinicians in charge of the patients. Portable supine chest radiography (CXR) and computed tomography (CT) were obtained within an interval of three hours. Using CT and chest drain as the gold standard, the diagnostic efficacy of US and CXR for the detection of pneumothorax, defined as rapidity and accuracy (sensitivity, specificity, positive predictive value, negative predictive value), were compared. The size of the pneumothorax (small, medium and large) determined by US was also compared to that determined by CT.ResultsOf 135 patients (injury severity score = 29.1 ± 12.4) included in the study, 83 received mechanical ventilation. The time needed for diagnosis of pneumothorax was significantly shorter with US compared to CXR (2.3 ± 2.9 versus 19.9 ± 10.3 minutes, p < 0.001). CT and chest drain confirmed 29 cases of pneumothorax (21.5%). The diagnostic sensitivity, specificity, positive and negative predictive values and accuracy for US and radiography were 86.2% versus 27.6% (p < 0.001), 97.2% versus 100% (not significant), 89.3% versus 100% (not significant), 96.3% versus 83.5% (p = 0.002), and 94.8% versus 84.4% (p = 0.005), respectively. US was highly consistent with CT in determining the size of pneumothorax (Kappa = 0.669, p < 0.001).ConclusionBedside clinician-performed US provides a reliable tool and has the advantages of being simple and rapid and having higher sensitivity and accuracy compared to chest radiography for the detection of pneumothorax in patients with multiple trauma.

A Prospective Comparison of Supine Chest Radiography and Bedside Ultrasound for the Diagnosis of Traumatic Pneumothorax

Background: Supine anteroposterior (AP) chest radiography may not detect the presence of a small or medium pneumothorax (PTX) in trauma patients. Objectives: To compare the sensitivity and specificity of bedside ultrasound (US) in the emergency department (ED) with supine portable AP chest radiography for the detection of PTX in trauma patients, and to determine whether US can grade the size of the PTX. Methods: This was a prospective, single-blinded study with convenience sampling, based on researcher availability, of blunt trauma patients at a Level 1 trauma center with an annual census of 75,000 patients. Enrollment criteria were adult trauma patients receiving computed tomography (CT) of the abdomen and pelvis (which includes lung windows at the authors' institution). Patients in whom the examination could not be completed were excluded. During the initial evaluation, attending emergency physicians performed bedside trauma US examinations to determine the presence of a sliding lung sign to rule out PTX. Portable, supine AP chest radiographs were evaluated by an attending trauma physician, blinded to the results of the thoracic US. The CT results (used as the criterion standard), or air release on chest tube placement, were compared with US and chest radiograph findings. Sensitivities and specificities with 95% confidence intervals (95% CIs) were calculated for US and AP chest radiography for the detection of PTX, and Spearman's rank correlation was used to evaluate for the ability of US to predict the size of the PTX on CT. Results: A total of 176 patients were enrolled in the study over an eight-month period. Twelve patients had a chest tube placed prior to CT. Pneumothorax was detected in 53 (30%) patients by US, and 40 (23%) by chest radiography. There were 53 (30%) true positives by CT or on chest tube placement. The sensitivity for chest radiography was 75.5% (95% CI = 61.7% to 86.2%) and the specificity was 100% (95% CI = 97.1% to 100%). The sensitivity for US was 98.1% (95% CI = 89.9% to 99.9%) and the specificity was 99.2% (95% CI = 95.6% to 99.9%). The positive likelihood ratio for a PTX was 121. Spearman's rank correlation showed at ρ of 0.82. Conclusions: With CT as the criterion standard, US is more sensitive than flat AP chest radiography in the diagnosis of traumatic PTX. Furthermore, US allowed sonologists to differentiate between small, medium, and large PTXs with good agreement with CT results.

A Prospective Comparison of Supine Chest Radiography and Bedside Ultrasound for the Diagnosis of Traumatic Pneumothorax

Supine anteroposterior (AP) chest radiography may not detect the presence of a small or medium pneumothorax (PTX) in trauma patients. To compare the sensitivity and specificity of bedside ultrasound (US) in the emergency department (ED) with supine portable AP chest radiography for the detection of PTX in trauma patients, and to determine whether US can grade the size of the PTX. This was a prospective, single-blinded study with convenience sampling, based on researcher availability, of blunt trauma patients at a Level 1 trauma center with an annual census of 75,000 patients. Enrollment criteria were adult trauma patients receiving computed tomography (CT) of the abdomen and pelvis (which includes lung windows at the authors' institution). Patients in whom the examination could not be completed were excluded. During the initial evaluation, attending emergency physicians performed bedside trauma US examinations to determine the presence of a sliding lung sign to rule out PTX. Portable, supine AP chest radiographs were evaluated by an attending trauma physician, blinded to the results of the thoracic US. The CT results (used as the criterion standard), or air release on chest tube placement, were compared with US and chest radiograph findings. Sensitivities and specificities with 95% confidence intervals (95% CIs) were calculated for US and AP chest radiography for the detection of PTX, and Spearman's rank correlation was used to evaluate for the ability of US to predict the size of the PTX on CT. A total of 176 patients were enrolled in the study over an eight-month period. Twelve patients had a chest tube placed prior to CT. Pneumothorax was detected in 53 (30%) patients by US, and 40 (23%) by chest radiography. There were 53 (30%) true positives by CT or on chest tube placement. The sensitivity for chest radiography was 75.5% (95% CI = 61.7% to 86.2%) and the specificity was 100% (95% CI = 97.1% to 100%). The sensitivity for US was 98.1% (95% CI = 89.9% to 99.9%) and the specificity was 99.2% (95% CI = 95.6% to 99.9%). The positive likelihood ratio for a PTX was 121. Spearman's rank correlation showed at rho of 0.82. With CT as the criterion standard, US is more sensitive than flat AP chest radiography in the diagnosis of traumatic PTX. Furthermore, US allowed sonologists to differentiate between small, medium, and large PTXs with good agreement with CT results.

Quantitative assessment of pleural effusion in critically ill patients by means of ultrasonography*

To assess the ability of ultrasonography to identify the presence and assess the volume of pleural effusion in the intensive care unit setting. Prospective descriptive clinical study. Medical-surgical intensive care unit of a teaching hospital. Initial study group (group I) consisted of 97 patients (mean [+/-SD] Simplified Acute Physiology Score II, 40 +/- 14) with clinically suspected pleural effusion. Fifty-one patients were mechanically ventilated and 55 patients underwent a unilateral or bilateral thoracentesis (58 procedures). All patients underwent supine chest radiography and pleural ultrasonography at bedside. The testing group (group II) consisted of 19 additional patients (17 under ventilation) who underwent thoracentesis. None. Maximal interpleural distance was measured at the base and apex of the pleural space, at both end-expiration and end-inspiration. In group I, interpleural distances were compared to actual volume of fluid in the subset of patients who underwent a complete thoracentesis (n = 49). Prediction of the volume of pleural effusion was subsequently tested prospectively in group II (25 complete thoracenteses). Portable chest radiography and pleural ultrasonography yielded discordant results for 47 patients (48%) in the diagnosis of pleural effusion. The expiratory interpleural distance measured at the thoracic base with ultrasonography was significantly correlated with the volume of fluid (p < .0001; coefficient of determination: right, 0.78; left, 0.51). A pleural effusion > or =800 mL was predicted when this distance was >45 mm (right) or >50 mm (left), with a sensitivity of 94% and 100% and a specificity of 76% and 67%, respectively. In group II, the mean bias between the predicted and observed volumes of pleural effusion determined by thoracentesis was 24 +/- 355 mL, and this decreased to 28 +/- 146 mL for the prediction of pleural effusion <1400 mL. Bedside ultrasonography is well suited for the quantitative assessment of unloculated pleural effusions in intensive care unit patients.

Hemodynamic and Pulmonary Changes after Drainage of Significant Pleural Effusions in Critically Ill, Mechanically Ventilated Surgical Patients

Our purpose was to study the effects of drainage of significant pleural effusions in mechanically ventilated patients in a surgical intensive care unit. Twenty-two ventilated patients in the surgical intensive care unit of a tertiary care center over a 12-month period who developed a pleural effusion large enough to require drainage were studied prospectively. All patients underwent serial portable chest radiography in the upright or semiupright position; the radiographs were reviewed by a radiology attending. Pleural effusions were classified as small, moderate, or large. Moderate or larger effusions were drained using an 8- to 12-Fr pigtail catheter inserted at the bedside under ultrasound guidance. Hemodynamic and pulmonary parameters were collected before and after the fluid was drained. Parameters studied included those outlined in the physiologic profile and included measured and calculated physiologic variables, arterial blood gas measurements, and Svo2 measurements. Ventilator settings before and after were also recorded. Average initial pleural effusion drainage was 1,262 +/- 762 mL (range, 300-2,980 mL). Nine of the 22 patients had effusions drained from both the right and left chest. Blood pressure, systemic vascular resistance, Po2, Pco2, Svo2, Fio2, peak airway pressure, and spontaneous volume did not change significantly. Pulmonary capillary wedge pressure decreased (17.4 +/- 6.0 before, 13.6 +/- 4.4 after; p < 0.01), central venous pressure decreased (14.2 +/- 5.2 before, 11.5 +/- 4.4 after; p < 0.02), and pulmonary arteriovenous shunt decreased (26.7 +/- 15.1 before, 21.0 +/- 7.8 after; p < 0.04). Oxygen delivery increased (579.7 +/- 214.7 before, 662.8 +/- 263.3 after; p < 0.01) and oxygen consumption increased (146.3 +/- 61.6 before, 175.2 +/- 73.8 after; p < 0.01). Respiratory rate also decreased (19.4 +/- 6.5 before, 15.5 +/- 6.3 after; p < 0.05). There were no complications from the placement of the pigtail catheters. Drainage of pleural effusions results in increased oxygen delivery and oxygen consumption coinciding with a decrease in pulmonary capillary wedge pressure. The pulmonary arteriovenous shunt decreased, implying an increase in functional residual capacity and improved oxygenation. Further study is needed to determine whether these changes lead to an improved patient outcome (i.e., reduction in length of stay, ventilator days, or mortality).

The impact of peer management on test-ordering behavior.

Laboratory testing of hospitalized patients, although essential, can be expensive and sometimes excessive. Attempts to reduce unnecessary testing have often been difficult to implement or sustain. Use of peer management through a resource utilization committee (RUC) to favorably modify test-ordering behavior in a large academic medical center. Interrupted time-series study. Medical center with inpatient care provider order entry (CPOE) system and database of ordered tests. Predominantly housestaff physicians but all clinical staff (attending physicians, housestaff, medical students, nurses, advance practice nurses, and other clinical staff) at Vanderbilt University Hospital who used CPOE systems. The RUC analyzed the ordering habits of providers during previous years and made 2 interventions by modifying software for the CPOE system. The committee first initiated a daily prompt in the system that asked providers whether they wanted to discontinue tests scheduled beyond 72 hours. After evaluating this first intervention, the committee further constrained testing options by unbundling serum metabolic panel tests (sodium, potassium, chloride, bicarbonate, glucose, blood urea nitrogen, and creatinine tests) into single components and by reducing the ease of repeating targeted tests (including electrolyte, blood urea nitrogen, creatinine, and glucose tests; electrocardiography; and portable chest radiography). Pre- and postintervention volumes of tests; proportion of patients with abnormal targeted chemistry levels after 48 hours; rates of repeated admission, transfer to intensive care units, and mortality; adjusted coefficient of variation for test ordering; and length of stay. Voluntary reduction of testing beyond 72 hours (first intervention) decreased orders for metabolic panel component tests by 24% (P = 0.02) and electrocardiograms by 57% (P = 0.006) but not orders for portable chest radiographs. Prospective constraints on recurrent test ordering with panel unbundling (second intervention) produced an additional decrease of 51% for metabolic panel component tests (P < 0.001) and 16% for portable chest radiographs (P = 0.03). Incidence of patients with abnormal targeted blood chemistry levels after 48 hours decreased after the intervention (P = 0.02). Postintervention-adjusted coefficients of variation decreased for metabolic panel component tests (P = 0.03) and electrocardiography (P = 0.04). Rates of (adjusted) monthly readmission, transfers to intensive care units, hospital length of stay, and mortality were unchanged. Other activities occurring during the time period of the interventions might have influenced some test-ordering behaviors, and we assessed effects on only a limited number of commonly ordered tests. Peer management reduced provider variability by addressing the imperfect ability of clinicians to rescind testing in a timely manner. Hospitals with growing health care costs can improve their resource utilization through peer management of testing behaviors by using CPOE systems.

Appendix 1: Portable Chest Radiography

Appendix 1: Portable Chest Radiography

Appendix 1: Portable Chest Radiography

Appendix 1: Portable Chest Radiography

Utility of Daily Routine Portable Chest Radiographs in Mechanically Ventilated Patients in the Medical ICU

To determine whether there is any difference in diagnostic, therapeutic, and outcome efficacy between protocols utilizing daily (ie, routine) chest radiographs (CXRs) and those utilizing clinically indicated (ie, nonroutine) CXRs in mechanically ventilated patients. Prospective, randomized, observational study. A 20-bed medical ICU at a university hospital. Adult patients who had been receiving mechanical ventilation for > 48 h. None. Ninety-four patients who had been intubated for at least 48 h were randomized to receive either routine or nonroutine CXRs and were observed until extubation or death. The percentage of CXRs with new findings was significantly larger in the nonroutine CXR group (53.1%; 120 CXRs) compared to that in the routine CXR group (33.4%; 98 CXRs; odds ratio [OR], 1.59; 95% confidence interval [CI], 1.16 to 2.18; p = 0.004). The number of CXRs with new findings that resulted in interventions was significantly larger in the nonroutine CXR group (26.5%; 60 CXRs) compared to that in the routine CXR group (13.3%; 39 CXRs; OR, 2.0; 95% CI, 1.29 to 3.08; p = 0.002). There was no difference in the mean duration of mechanical ventilation (routine CXR arm, 7.93 days; nonroutine CXR arm, 6.76 days; p = 0.2606), length of ICU stay (routine CXR arm, 11.93 days; nonroutine CXR arm, 9.55 days; p = 0.1936), and total length of hospital stay (routine CXR arm, 19.34 days; nonroutine CXR arm, 16.45 days; p = 0.2199) between the two groups. Although patients in the nonroutine arm of the study received fewer CXRs, adverse outcomes (eg, length of mechanical ventilation, length of hospital stay, length of ICU stay, and mortality) did not increase (p = 0.818). Using the number of CXRs per patient as a surrogate, there was a statistically significant cost savings and decreased radiation exposure in the nonroutine CXR group. For mechanically ventilated patients, a strategy calling for daily routine CXRs compared to CXRs obtained based on clinical indications alone was not associated with reduced ICU or hospital length of stay or with reduced mortality.

Diagnosis of Ventilator‐Associated Pneumonia: Where Do We Go from Here?

Diagnosis of Ventilator‐Associated Pneumonia: Where Do We Go from Here?

Portable chest radiographs in the intensive care units: referral patterns and estimated cumulative radiation exposures.

The objective of this article was to determine the frequency of referrals for portable chest radiographs from medical and (noncardiac) surgical intensive care units (NICU and SICU) and their respective stepdown units (NICA and SICA). Additionally, the cumulative entrance skin exposure (ESE) using an ion chamber was determined. We retrospectively reviewed the medical records of all adult patients admitted to the MICU, SICU, MICA, and SICA at a tertiary referral center during a 6-month interval. The duration of stay and the number of portable chest radiographs were determined for each patient. The measured ESEs from all portable radiography units ranged from 5 to15 mR (average: 10mR). The cumulative radiation exposure for each patient was calculated. There were 567 patients admitted to the units: 146 surgical and 421 medical. Their ages ranged from 15 to 87 years. The duration of stay varied from 1 to 68 days. A total of 3,794 portable chest radiographs were obtained. The number of radiographs per patient varied from 1 to 94. The number of radiographs and the corresponding cumulative radiation doses were as follows: 406 patients (72%) had fewer than five radiographs (<50 mR); 76 (13%) had five to 10 radiographs (<100 mR); 35 (6%) had 11 to 20 (<200 mR); and 50 (9%) had more than 20 chest radiographs (>200 mR). The cumulative ESE ranged from 10 to 940 mR. It exceeded 450 mR in only nine (1.5%) patients. Most (73%) patients undergoing intensive care undergo fewer than five radiographs during their stay in the units. Patient exposure from portable chest radiographs in this population is less than the average annual exposure from background radiation in the USA (450-500 mR), and is much less than the average annual exposure from teratogenic radiation.

The hazard of scattered radiation in a trauma intensive care unit.

Patients admitted to the trauma intensive care unit (TICU) often require bedside imaging procedures such as radiographs, fluoroscopic placement of enteral feeding tubes, and insertion of vena cava filters. The potential for scattered radiation exposure is a concern to healthcare workers. Our study's purpose was to measure the level of scattered ionizing radiation present in a TICU. This prospective study was conducted over 3 months in an open-design, ten-bed TICU of a Level I trauma center. Fifteen dosimeters were placed in selected areas of the TICU to measure the amount of scattered radiation present. Standard radiation protection precautions were used throughout the study period. At the end of each month, data from the dosimeters were sent to the manufacturer for analysis. One thousand seventy-four radiologic studies were performed at the bedside during the study period (803 portable chest radiographs, 103 abdominal radiographs, 303 extremity radiographs, 223 spine radiographs, and 15 fluoroscopic procedures). Dosimetry analysis showed <5 mrem (1/1000 roentgen equivalent in man) scattered radiation per month (<60 mrem/year) in each of the monitored areas. All monitored areas measured <2 mrem per week of scattered radiation when adjusted for occupancy. The level of scattered radiation in our TICU is less than the recommended allowable exposure of <100 mrem/year, indicating that radiation exposure is not a significant occupational hazard in our TICU, even in the setting of frequent use of bedside imaging studies.

Effect of weight loss in congestive heart failure from idiopathic dilated cardiomyopathy on electrocardiographic QRS voltage

It was appreciated in the 1950s and 1960s that patients with congestive heart failure (CHF) had lower QRS voltages on their electrocardiograms than they had when compensated.1–4 Also, 30 years ago Ishikawa et al5 documented an increase in ECG voltages in 12 patients after treatment of CHF, whereas a decrease in the QRS amplitudes occurred in 3 patients with poor response to therapy.5 Recently, a phenomenon consisting of a reduction in ECG amplitude commensurate with weight gain in patients with anasarca was reported6; the involved patients had a variety of critical illnesses, mainly sepsis, and required administration of large volumes of intravenous fluids. During the last month of implementation of this study,6 we encountered in the coronary care unit 3 patients with CHF who had the reverse phenomenon, i.e., an increase in the amplitude of electrocardiograms in response to treatment of CHF, and a resultant loss of weight. These were the only patients admitted in the course of 1 month, with CHF and visible “pitting” peripheral edema in the pretibial aspect of their legs and the dorsum of their feet. Daily weights and standard electrocardiograms were obtained. Measurements to the nearest 0.5 mm of the amplitude (highest positive + lowest negative deflections) of the QRS complex of all 12 leads were obtained by 1 of the investigators (JEM) using a magnifying glass and calipers. Calibration was 1 mV = 10 mm. Sums of the QRS amplitudes of all leads (ΣQRS) were calculated for electrocardiograms of each patient from the days corresponding to the initial (peak) and the lowest weights attained in response to therapy for CHF. Both the change in weights and ΣQRS, and the adjusted values to the commencement of therapy as a percent change were used as variables. The intraobserver variability of ΣQRS in 10 random electrocardiograms from a previous study was found to be 0.41 ± 3.34% (mean ± SD).6 Because hematocrit change may affect blood conductivity,7,8 and thus the amplitude of ECG potentials, this parameter was followed closely. Electrolytes were monitored, and supplemental potassium was administered. Frequent portable chest radiographs were obtained in the study patients to evaluate heart size and status of pulmonary congestion, and its change. Echocardiograms were obtained to assess cardiac structure and function. Management of CHF was done routinely.

Chest radiographs of limited utility in the diagnosis of blunt traumatic aortic laceration.

The radiographic diagnosis of blunt traumatic aortic laceration (BTAL) remains problematic. We reviewed our experience with chest radiographic signs of BTAL at a single trauma center. The chest radiographs of 188 consecutive blunt trauma patients with suspected BTAL who underwent portable chest radiography and aortography were retrospectively reviewed by a thoracic radiologist. The presence or absence of 15 radiographic findings were recorded, and the sensitivity and specificity of individual radiographic signs and combinations of signs were determined. There were 10 patients with BTAL. Although three signs showed greater than 90% sensitivity for BTAL, these signs showed low specificity, and no significant improvement in overall accuracy was achieved by combining radiographic findings. The experience at our institution suggests that chest radiographs have limited utility in the accurate diagnosis of blunt traumatic aortic laceration. Cross-sectional imaging techniques will likely become the preferred imaging procedures for evaluating patients with suspected BTAL.

Significance of backboard artifacts on portable trauma series chest radiographs

Purpose: To evaluate the degree to which the artifacts created by the radio-opaque components of a backboard obscure the findings on the initial trauma series chest radiograph (BBCXR). Methods: We reviewed 40 consecutive trauma victims admitted to our level I trauma center over a 3-month period who underwent a follow-up portable supine chest radiograph (PCXR) off the backboard no longer than 1 h after the initial trauma BBCXR. The original interpretation of the BBCXR was compared to the reading of the PCXR as well as to a retrospective analysis of the BBCXR performed by two radiologists blinded as to the findings on the original report. Results: The initial interpretation of the BBCXR failed to identify abnormalities reported in the follow-up PCXR of 10 individuals (25 %), most frequently bone fractures, misplaced hardware, and pleural effusions. Of these missed abnormalities, 80 % were identified retrospectively. Conversely, the initial reading of the BBCXR described a widened mediastinum in five cases, right upper lobe opacities in two, and cardiomegaly in one. Of these eight reported findings, only five (63 %) – the cardiomegaly and four of the mediastinal abnormalities – were also reported upon retrospective analysis, while the PCXR taken with the patient off the backboard confirmed widened mediastinum in only three cases. Conclusions: The initial, often hurried reading of a portable chest radiograph taken on a backboard as part of a trauma series often misses significant pathology, most of which can be detected upon more thorough examination of the original film. The backboard also tends to magnify mediastinal structures more than routine PCXR. Therefore, we advocate a more cautious analysis of the original BBCXR and routine utilization of a follow-up PCXR to confirm mediastinal abnormalities.

Portable CT: assessing thoracic disease in the intensive care unit.

The objective of this study was to assess the usefulness of a portable CT scanner to evaluate and treat thoracic disease in patients in the intensive care unit. Fourteen patients who were being treated in the intensive care unit underwent 20 portable CT scans. Twice a CT scan was obtained to guide an interventional chest procedure. The remaining 18 scans were assessed for findings not evident on portable chest radiography and for findings that altered treatment. Image quality was judged in comparison with fixed CT scans. Unsuspected abnormalities, most relating to the pleura or chest wall, were found in 13 of the 17 available portable CT scans. Treatment was affected in four (25%) of the 16 cases in which medical records were available for review. Two interventional procedures were performed successfully using portable CT guidance. Scan quality was judged to be comparable with that of fixed CT for mediastinal windows and somewhat inferior for lung windows. Portable CT gives images of diagnostic quality and allows confident guidance during interventional procedures in critically ill patients who therefore need not leave the intensive care unit environment.

Utility of portable chest radiographs as a predictor of endotracheal tube cuff pressure

Increased endotracheal tube cuff pressure causes mucosal ischemia that can lead to necrosis, infection, and, eventually, tracheomalacia or tracheal stenosis. Endotracheally intubated patients frequently undergo portable chest radiography. In this study we explored the relationship of endotracheal tube cuff pressure and the appearance on the tracheal air columns on the portable chest radiograph. We measured the endotracheal tube cuff pressure of intensive care unit patients 124 times immediately before portable chest radiography. On 64 of these radiographs we measured the width of the tracheal air column below the tip of the endotracheal tube and at the maximal diameter of the endotracheal tube balloon. We then analyzed the relationship of cuff pressure to tracheal dilation. The results of ANOVA of tracheal dilation for three groups (safe, borderline, and unsafe cuff pressures) were significant. Large overlapping ranges existed in each group. Regression analysis confirmed a linear relationship between cuff pressure and tracheal dilation ( r = 0.435, p < 0.001). Predicted tracheal expansion at 20 mm Hg was a poor screen for endotracheal tube cuff inflation safety; the sensitivity was only 56% and specificity only 71%. The differences in the capacity for tracheal distension between patients make these findings not unexpected. The portable chest radiograph is a poor screening tool for unsafe endotracheal tube cuff pressure. (Otolaryngol Head Neck Surg 1999;120:51-6.)