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Biomedical subjects

E W Ely

Publications and source records attributed to E W Ely.

At least 37 records · Page 2Linked to original sources
PubMed2000

Education of physicians-in-training can decrease the risk for vascular catheter infection.

BACKGROUND: Procedure instruction for physicians-in-training is usually nonstandardized. The authors observed that during insertion of central venous catheters (CVCs), few physicians used full-size sterile drapes (an intervention proven to reduce the risk for CVC-related infection). OBJECTIVE: To improve standardization of infection control practices and techniques during invasive procedures. DESIGN: Nonrandomized pre-post observational trial. SETTING: Six intensive care units and one step-down unit at Wake Forest University Baptist Medical Center, Winston-Salem, North Carolina. PARTICIPANTS: Third-year medical students and physicians completing their first postgraduate year. INTERVENTION: A 1-day course on infection control practices and procedures given in June 1996 and June 1997. MEASUREMENTS: Surveys assessing physician attitudes toward use of sterile techniques during insertion of CVCs were administered during the baseline year and just before, immediately after, and 6 months after the first course. Preintervention and postintervention use of full-size sterile drapes was measured, and surveillance for vascular catheter-related infection was performed. RESULTS: The perceived need for full-size sterile drapes was 22% in the year before the course and 73% 6 months after the course (P < 0.001). The perceived need for small sterile towels at the insertion site decreased reciprocally (P < 0.001). Documented use of full-size sterile drapes increased from 44% to 65% (P < 0.001). The rate of catheter-related infection decreased from 4.51 infections per 1000 patient-days before the first course to 2.92 infections per 1000 patient-days 18 months after the first course (average decrease, 3.23 infections per 1000 patient-days; P < 0.01). The estimated cost savings of this 28% decrease was at least $63000 and may have exceeded $800000. CONCLUSIONS: Standardization of infection control practices through a course is a cost-effective way to decrease related adverse outcomes. If these findings can be reproduced, this approach may serve as a model for physicians-in-training.

Bacteremia↗
PubMed2000

Active CMV infection before lung transplantation: risk factors and clinical implications.

BACKGROUND: Cytomegalovirus (CMV) infection is a major cause of morbidity following lung transplantation, but active CMV infection has not been described before transplantation. Since 1990, we have screened all lung-transplant recipients for CMV infection with viral urine cultures on the day of transplantation. We retrospectively reviewed the medical records of all 102 lung-allograft recipients transplanted between March 1990 and September 1998. Patients with positive urine cultures for CMV were compared to culture negative patients for age, gender, pretransplant diagnosis, time from diagnosis to transplantation, CMV serostatus, use of pretransplant immunosuppression, T-lymphocyte subsets, and presence of fever. Posttransplant outcomes assessed were duration of intubation and hospitalization, acute rejection, frequency of CMV disease, duration of Nashville rabbit antithymocyte serum or globulin (N-RATS/G) and ganciclovir, and survival. Five (5%) of 102 patients had positive urine cultures for CMV; none had symptoms of CMV infection. All 5 had idiopathic pulmonary fibrosis (IPF) (5/5 vs 27/97; p = 0.002). The age, gender, and CMV serostatus of these patients did not differ from the 97 patients in the culture negative group. Four (80%) of the 5 patients with positive cultures were receiving treatment with azathioprine or cyclophosphamide vs only 18 (19%) of the 97 patients with negative cultures (p = 0.007), and all 5 (100%) were receiving steroids compared to 50 (52%) of 97 patients with negative cultures (p = 0.06). Culture-positive IPF patients, when compared with the 27 culture-negative IPF patients, did not differ in any demographic variable or in the use of immunosuppression, but culture-positive patients were more likely to have a CD4/CD8 T-cell subset ratio <1.0 (p = 0.02). Following transplantation, 3 (60%) of 5 IPF patients with positive CMV cultures developed CMV disease compared to 3 (11%) of 27 IPF patients with negative cultures (p = 0.03). Patients with positive cultures also received more days of parenteral antiviral therapy (mean 44 +/- 11 days vs 16 +/- 10 days; p < 0.001). Utilizing pretransplant screening, we have discovered that 16% of patients with IPF had active CMV infection, which was associated with both alterations in their T-cell subsets and a greater risk for CMV disease after transplantation. This occurrence of occult CMV infection in patients with IPF has not been previously recognized, and has important implications.

Animals↗
PubMed2000

Lung allocation in the United States, 1995-1997: an analysis of equity and utility.

BACKGROUND: Waiting time for organ transplantation varies widely between programs of different sizes and by geographic regions. The purpose of this study was to determine if the current lung-allocation policy is equitable for candidates waiting at various-sized centers, and to model how national allocation based solely on waiting time might affect patients and programs. METHODS: UNOS provided data on candidate registrations; transplants and outcomes; waiting times; and deaths while waiting for all U.S. lung-transplant programs during 1995-1997. Transplant centers were categorized based on average yearly volume: small (< or = 10 pounds sterling transplants/year; n = 46), medium (11-30 transplants/year; n = 29), or large (>30 transplants/year; n = 6). This data was used to model national organ allocation based solely on accumulated waiting time for candidates listed at the end of 1997. RESULTS: Median waiting time for patients transplanted was longest at large programs (724-848 days) compared to small and medium centers (371-552 days and 337-553 days, respectively) and increased at programs of all sizes during the study period. Wait-time-adjusted risk of death correlated inversely with program size (365 vs 261 vs 148 deaths per 1,000 patient-years-at-risk at small, medium, and large centers, respectively). Mortality as a percentage of new candidate registrations was similar for all program categories, ranging from 21 to 25%. Survival rates following transplantation were equivalent at medium-sized centers vs large centers (p = 0.50), but statistically lower when small centers were compared to either large- or medium-size centers (p < or = 0.05). Using waiting time as the primary criterion lung allocation would acutely shift 10 to 20% of lung-transplant activity from medium to large programs. CONCLUSIONS: 1) Waiting list mortality rates are not higher at large lung-transplant programs with long average waiting times. 2) A lung-allocation algorithm based primarily on waiting-list seniority would probably disadvantage candidates at medium-size centers without improving overall lung-transplant outcomes. 3) If fairness is measured by equal distribution of opportunity and risk, we conclude that the current allocation system is relatively equitable for patients currently entering the lung-transplant system.

Actuarial Analysis↗
PubMed2000

The utility of weaning protocols to expedite liberation from mechanical ventilation.

Over the past decade, a number of studies have examined methods of hastening liberation of patients from mechanical ventilation. This article outlines weaning protocols that have been proven superior to weaning performed by board-certified intensivists. The author also presents techniques to faciliate the implementation of weaning protocols based on the published experience of one hospital.

Clinical Protocols↗
PubMed2000

The distribution of costs of care in mechanically ventilated patients with chronic obstructive pulmonary disease.

OBJECTIVES: To delineate the costs of care of patients with Chronic Obstructive Pulmonary Disease (COPD) and respiratory failure and to compare them with those of other mechanically ventilated patients. DESIGN: A post hoc analysis of a prospective investigation. SETTING: Medical and coronary intensive care units (ICUs) of an 804-bed, university-based hospital. PATIENTS: A total of 300 mechanically ventilated patients, 44 with COPD and 256 others, were included. MEASUREMENTS AND MAIN RESULTS: Despite similar lengths of ICU stay (9 days) and mechanical ventilation (5.5 days COPD vs. 5 days other, p = .11), ICU respiratory care costs for patients with COPD were $2,422 ($1,157-$6,110) [median U.S. dollars (interquartile range)] vs. $1,580 ($738-$3,322) for the others (p = .01). Ventilator costs for COPD patients were $1,795 ($943-$5,782) vs. $1,574 ($613-$3,112) (p = .12). Total hospitalization respiratory care costs for COPD patients were higher, $4,064 ($2,422-$9,572) vs. $2,342 ($1,186-$4,591), (p = .0001), and 74.4% of the median difference in cost between COPD patients and others was accounted for by spontaneous nebulizers (p = .001), metered dose inhalers (p = .01), and pulse oximetry (p = .02). By using multiple linear regression analyses, we found that COPD remained associated with higher respiratory costs (p<.05). Respiratory Care was the third largest category of hospital costs after beds (27%) and pharmacy expenses (25%), and it comprised approximately 14% of total cost. Total hospital costs were large for both groups, but did not differ between COPD and the others [$24,217 ($16,211-$58,834) vs. $27,672 ($15,692-$53,766), respectively (p = .96)]. Linear regression analyses showed that only Acute Lung Injury score was significantly related to total ICU and hospital costs of care (p<.05). CONCLUSIONS: Costs of ICU and non-ICU respiratory care for patients with COPD are higher than costs of care for other mechanically ventilated patients. Although the increased cost of bronchodilators and oximetry in these patients may serve as target areas for reductions in respiratory care costs, it may also be true that these modalities of therapy and management are necessary and need to be used with even greater intensity to achieve better outcomes. The predominant contributions of bed and pharmacy costs in all of our patients with respiratory failure support research efforts addressing these aspects of care.

Aged↗
PubMed2000

Living and dying with chronic obstructive pulmonary disease.

OBJECTIVE: To characterize chronic obstructive pulmonary disease (COPD) over patients' last 6 months of life. STUDY DESIGN: A retrospective analysis of a prospective cohort from the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT). SETTING: Hospitalization for exacerbation of COPD at five US teaching hospitals. PARTICIPANTS: COPD patients who died within 1 year (n = 416) among 1016 enrolled. METHODS: Interview and medical record data were organized into time windows beginning with death and ending 6 months earlier. OUTCOME MEASURES: Days in hospital, prognosis, illness severity, function, symptoms, patients' preferences, and impacts on families. RESULTS: One-year survival was 59%, 39% had > or = 3 comorbidities, and 15 to 25% of the patients' last 6 months were in hospitals. Exacerbation etiologies included respiratory infection (47%) and cardiac problems (30%). Better quality of life predicted longer survival (ARR: 0.36; 95% CI, 0.19-0.87) as did heart failure etiology of exacerbation (ARR: 0.57; CI, 0.40, 0.82). Estimates of survival by physicians and by prognostic model were well calibrated, although patients with the worst prognoses survived longer than predicted. Patients' estimates of prognosis were poorly calibrated. One-quarter of patients had serious pain throughout, and two-thirds had serious dyspnea. Patients' illnesses had a major impact on more than 25% of families. Patients' preferences for Do-Not-Resuscitate orders increased from 40% at 3 to 6 months before death to 77% within 1 month of death; their decisions not to use mechanical ventilation increased from 12 to 31%, and their preferences for resuscitation decreased from 52 to 23%. CONCLUSIONS: Patients with advanced COPD often die within 1 year and have substantial comorbidities and symptoms. Adequate description anchors improved care.

Aged↗
PubMed2000

Flock worker's lung: broadening the spectrum of clinicopathology, narrowing the spectrum of suspected etiologies.

STUDY OBJECTIVES: Workers in the nylon flocking industry recently have been found to be at increased risk of chronic nongranulomatous interstitial lung disease. Although a spectrum of cytologic and histopathologic abnormalities has been observed, nonspecific interstitial pneumonia, lymphoid nodules, and lymphocytic bronchiolitis predominated in the 19 previously reported cases of flock worker's lung. Here we describe five additional patients who appear to expand the histopathologic spectrum and add to the evidence suggesting a causative role for respirable-sized nylon fragments. METHODS: We studied all North American patients (n = 5) found in 1998 to satisfy our previous case definition of flock worker's lung. Two pulmonary pathologists independently reviewed each biopsy specimen. RESULTS: All five patients reported cough and dyspnea. Only one patient had crackles on chest auscultation. High-resolution CT scan, interpreted with attention to subtle ground-glass attenuation, remained a highly sensitive diagnostic test. Pulmonary function tests and plain chest radiograph were less sensitive. One patient's wedge biopsy showed previously described prototypical findings. Two others had transbronchial biopsies showing some of the same features. The fourth patient's wedge biopsy showed desquamative interstitial pneumonia. The fifth patient had bilateral synchronous adenocarcinoma but with radiographic evidence of diffuse interstitial fibrosis. These 5 patients and the 19 patients studied previously were exposed to nylon flock manufactured by a rarely used cutting technology. CONCLUSION: Findings in these five patients appear to broaden the spectrum of the clinicopathology of flock worker's lung and add to the evidence incriminating respirable-sized nylon particulates produced during the manufacture and use of rotary-cut nylon flock.

Adult↗
PubMed2000

Pulmonary veno-occlusive disease: a case series and new observations.

STUDY OBJECTIVES: The aim of this study was to describe our experience at one institution with pulmonary veno-occlusive disease (PVOD) during the past 10 years, with particular reference to new findings and long-term outcome. SETTING: Tertiary care, academic medical center. PATIENTS AND METHODS: Eleven patients who were evaluated and treated for PVOD at our institution were retrospectively studied. Included were all available clinical, radiographic, hemodynamic, and pathologic data. RESULTS: All 11 patients in our series had at least one symptom or clinical finding that, in conjunction with known pulmonary hypertension, suggested the diagnosis of PVOD. Digital clubbing, not previously reported in PVOD, was found in 5 patients, rales in 6, and increased interstitial markings on chest radiograph in 10. Half of the 10 patients who underwent acute vasodilator testing exhibited a decrease in pulmonary artery pressure of > 20%, although one patient died shortly after receiving IV calcium-channel blockers. Three patients have demonstrated sustained clinical improvement with therapy, which includes calcium-channel blockers, epoprostenol, and lung transplantation in one patient each. However, outcome was generally poor, with a 72% mortality within 1 year of diagnosis. CONCLUSION: The diagnosis of PVOD requires a high clinical suspicion. However, both physical examination findings and radiographic studies often provide clues to the diagnosis, which may obviate the need for lung biopsy in the majority of cases. Although there may be patients who respond to medical therapy, the use of vasoactive medications in patients with PVOD should be undertaken with great caution. Long-term survival is poor, and lung transplantation remains the only proven therapy.

Adult↗
PubMed1999

Mechanical ventilation in a cohort of elderly patients admitted to an intensive care unit.

BACKGROUND: It has been argued that life support for the elderly should be limited to conserve resources. As this population increases, so will the importance of evaluating appropriate use of mechanical ventilation in this group. OBJECTIVE: To determine whether age has an independent effect on the outcomes of patients treated with mechanical ventilation after admission to an intensive care unit (ICU). DESIGN: Prospective cohort study. SETTING: University-based tertiary care medical center. PATIENTS: 63 patients 75 years of age or older and 237 patients younger than 75 years of age enrolled from medical and coronary ICUs. MEASUREMENTS: In-hospital mortality rate, duration of mechanical ventilation, lengths of stay in the ICU and in the hospital, and cost of care. RESULTS: Median duration of mechanical ventilation was 4.2 days (interquartile range, 2.1 to 9.3 days) for patients 75 years of age or older and 6.4 days (interquartile range, 3.4 to 11.4 days) for patients younger than 75 years of age (P = 0.14). When the length of time required to "pass" a daily screening test of weaning variables was used as an indicator of recovery from respiratory failure, elderly patients passed earlier than younger patients (risk ratio, 1.58 [95% CI, 1.13 to 2.22]; P = 0.03). The cost of ICU care was lower for older ($12,822 [CI, $9821 to $26,313] than for younger ($19,316 [CI, $9699 to $39,950]) patients (P = 0.03). Median hospital costs tended to be lower in the older group ($21,292 compared with $29,049; P = 0.17). After adjustment for ethnicity, sex, and severity of illness in a multivariate logistic regression analysis, patient age of 75 years or older was predictive of 1 less day on the ventilator (CI, -2.8 to 1.2 days). Lengths of stay in the ICU (beta-coefficient, -0.5 days [CI, -3.0 to 2.7 days]) and in the hospital (beta-coefficient, 0.3 days [CI, -3.7 to 5.5 days]) did not differ for persons 75 years of age or older after these adjustments (P > 0.1). Intensive care unit and hospital costs, however, were lower for elderly persons (P = 0.02). The in-hospital mortality rate was 38.1% among elderly patients and 38.8% among younger patients (P > 0.2); Cox proportional hazards analysis confirmed that survival did not differ between the two groups (relative risk for older patients, 0.82 [CI, 0.52 to 1.29]). CONCLUSIONS: After adjustment for severity of illness, elderly patients spent similar time on mechanical ventilation and in the ICU and hospital but had a lower cost of care than younger patients. These outcomes are not explained by differences in mortality rate and suggest that mechanical ventilation should not be restricted in elderly patients with respiratory failure on the basis of chronologic age.

APACHE↗
PubMed1999

The prognostic significance of passing a daily screen of weaning parameters.

OBJECTIVE: While "weaning parameters" are commonly used to guide removal of mechanical ventilation devices, little information exists concerning their prognostic value. We evaluated whether passing weaning parameters was associated with survival. DESIGN: A prospectively followed cohort of mechanically ventilated patients. SETTING: Medical and coronary adult intensive care units of an 806-bed medical center. PATIENTS: 300 consecutively enrolled mechanically ventilated patients. MEASUREMENTS AND RESULTS: 216 patients who passed a daily screen of weaning parameters were more likely to be extubated successfully (87 vs 30%, p = 0.0001), less likely to require ventilation for > 21 days (3 vs 30%, p = 0.0001), and had a higher survival to hospital discharge (74 vs 29%, p = 0.0001) than 84 patients who never passed the screen. The overall accuracy of the daily screen for predicting successful extubation and in-hospital survival was 82 and 73%, respectively. Multivariate proportional hazards analysis of time until hospital death confirmed the beneficial effect of passing the daily screen (p = 0.01) and of duration of mechanical ventilation (p = 0.001) even after adjustment for differences in severity of illness, age, race, gender, diagnosis, and treatment assignment. While liberation from mechanical ventilation was predictive of survival at any time during the hospital stay (p = 0.001), the prognostic significance of the daily screen for hospital survival was related to how early after intubation it was passed. The difference in survival between patients who had passed and those who had not passed the daily screen was significant for 1 1/2 weeks postintubation but progressively decreased over time. The average time to extubation after passing the daily screen increased from 3 days (range 0 to 56), for those passing within 5 days of intubation, to 8 days (0 to 35), for those passing after 10 days of intubation (r = 0.26, p = 0.001). CONCLUSIONS: Passing a daily screen of weaning parameters is an independent predictor of successful extubation and survival, but its prognostic value decreases over time. Time spent on mechanical ventilation after passing the daily screen presents an important opportunity to optimize liberation from the ventilator.

Adult↗
PubMed1999

Venous air embolism from central venous catheterization: a need for increased physician awareness.

OBJECTIVES: To report a series of patients with clinically diagnosed venous air embolism (VAE) and major sequelae as a complication of the use of central venous catheters (CVCs), to survey health care professionals' practices regarding CVCs, and to implement an educational intervention for optimizing approaches to CVC insertion and removal. SETTING: Tertiary care, university-based 806-bed medical center. INTERVENTIONS: We surveyed 140 physicians and 53 critical care nurses to appraise their awareness of the proper management and complications of CVCs. We then designed, delivered, and measured the effects of a multidisciplinary educational intervention given to 106 incoming house officers. MEASUREMENTS AND MAIN RESULTS: Although most physicians (127, 91%) chose the Trendelenburg position for CVC insertion, only 42 physicians (30%) reported concern for VAE. On CVC removal, only 36 physicians (26%) cited concern for VAE. Some physicians (13, 9%) reported elevating the head of the bed during CVC removal, possibly increasing the risk of VAE. Awareness of VAE or its prevention did not correlate with the level of physician training, experience, or specialty. After the educational intervention, concern for and awareness of proper methods of prevention of VAE improved (p < .001). At 6-month follow-up, reported use of the Trendelenburg position continued, but concern cited for VAE had returned to baseline. CONCLUSIONS: There is inadequate awareness of VAE as a complication of CVC use. Focused instruction can improve appreciation of this potentially fatal complication and knowledge of its prevention, but the effect declines rapidly. To achieve a more sustained improvement, a more intensive, hands-on, periodic educational program will likely be necessary, as well as reinforcement through enhanced supervision of CVC insertion and removal practices.

Academic Medical Centers↗
PubMed1999

Large scale implementation of a respiratory therapist-driven protocol for ventilator weaning.

We prospectively investigated the large-scale implementation of a respiratory-therapist-driven protocol (TDP) that included 117 respiratory care practitioners (RCPs) managing 1,067 patients with respiratory failure over 9,048 patient days of mechanical ventilation. During a 12-mo period, we reintroduced a previously validated protocol that included a daily screen (DS) coupled with spontaneous breathing trials (SBTs) and physician prompt, as a TDP without daily input from a physician or "weaning team." With graded, staged educational interventions at 2-mo intervals, RCPs had a 97% completion rate and a 95% correct interpretation rate for the DS. The frequency with which patients who passed the DS underwent SBTs increased throughout the implementation process (p < 0.001). As the year progressed, RCPs more often considered SBTs once patients had passed a DS (p < 0.001), and physicians ordered more SBTs (46 versus 65%, p = 0.004). Overall, SBTs were ordered more often on the medicine than on the surgical services (81 versus 63%, p = 0.001), likely reflecting medical intensivists' prior use of this protocol. Important barriers to protocol compliance were identified through a questionnaire (89 respondents, 76%), and included: Physician unfamiliarity with the protocol, RCP inconsistency in seeking an order for an SBT from the physician, specific reasons cited by the physician for not advancing the patient to a SBT, and lack of stationary unit assignments by RCPs performing the protocol. We conclude that implementation of a validated weaning strategy is feasible as a TDP without daily supervision from a weaning physician or team. RCPs can appropriately perform and interpret DS data more than 95% of the time, but significant barriers to SBTs exist. Through a staged implementation process, using periodic reinforcement of all participants in ventilator management, improved compliance with this large-scale weaning protocol can be achieved.

Clinical Protocols↗
PubMed1998

Cryptococcal pneumonia complicating pregnancy.

In the present report we describe 4 previously healthy women who developed cryptococcal pneumonia during pregnancy, and 1 pregnant woman with cryptococcal meningitis. These cases illustrate a previously uncharacterized spectrum of cryptococcal disease. We also discuss 24 patients previously reported who had cryptococcal meningitis during pregnancy. Finally, we review the available data for each therapeutic option and present an algorithm for management based on appraisals of disease severity and risk to the unborn fetus. This report emphasizes the need for heightened awareness of cryptococcosis in the differential diagnosis of pneumonia, chest pain, and hypoxemia in the pregnant patient, but at present, there are insufficient epidemiologic data to determine whether incidences of pulmonary or disseminated cryptococcosis actually increase during pregnancy. The risk of congenital cryptococcosis to the unborn fetus is low, and the most likely mechanism whereby neonates acquire invasive fungal pulmonary infection is through aspiration. While it is unclear whether there is any real increased risk of spontaneous abortion or premature labor, the data indicate that overall fetal outcome depends on effective treatment of maternal infection. For patients with dense air-space consolidation, progressive pulmonary disease, or dissemination, antifungal therapy is necessary. Optimal treatment is determined by the acuity and severity of the clinical presentation. Amphotericin B (approximately 1 g) with or without flucytosine represents the choice for initial treatment of the more acutely ill patient with disseminated or progressive pulmonary cryptococcosis who requires hospitalization (whether during or after pregnancy). Oral fluconazole appears to be safe and effective alternative therapy after delivery for the less severely ill patient who can be managed on an outpatient basis. While the use of fluconazole during pregnancy generally appears safe in terms of fetal outcome (49, 58), the class C status and single report of fetal malformation (62) preclude confident recommendation for its use during pregnancy. The risks and benefits of this effective and generally less toxic drug should be discussed with the parents and weighed against the use of amphotericin B. For pregnant women with limited pulmonary cryptococcosis (segmental or nodular infiltrates) and no evidence of dissemination, we recommend close follow-up without antifungal therapy similar to the recommendation for normal hosts with minimal disease. However, it is important to note that there is no extensive experience upon which to base this recommendation for pregnant individuals (45, 55, 103, 108). It is prudent to use frequent physical examinations (for example, every 1-2 months), combined with chest roentgenograms and serum cryptococcal antigens to monitor progression and/or development of disease in both the mother and child for approximately 6 months postpartum. In conclusion, cryptococcosis during pregnancy presents a special challenge to the clinician. A balanced therapeutic approach holds great promise for successful maternal and fetal outcomes.

Adult↗
PubMed1998

Appraising pulmonary edema using supine chest roentgenograms in ventilated patients.

The role of portable, anteroposterior, supine chest X-rays (CXRs) in distinguishing hydrostatic pulmonary edema (HPE) from permeability pulmonary edema (PPE) in mechanically ventilated patients is controversial. We prospectively obtained and evaluated such CXRs in 33 supine, mechanically ventilated intensive-care-unit patients with pulmonary artery catheters. Three chest radiologists independently reviewed CXRs without clinical information and recorded the cardiothoracic (CT) ratio, vascular pedicle width (VPW), and other radiographic features commonly used to evaluate pulmonary edema. Hydrostatic pulmonary edema was associated with a larger CT ratio (p < 0.001), subjective impressions of cardiomegaly (p < 0.01), and increased VPW (p = 0.02). There was a significant correlation between the pulmonary artery occlusion pressure and the VPW (r = 0.45, p = 0.0076) and CT ratio (r = 0.52, p = 0.0016), as well as between the VPW and CT ratio (r = 0.49, p = 0.0032). Despite this detailed evaluation of the CXRs, the mean accuracy of the radiologists' clinical diagnosis of HPE versus PPE was 41%, and 15 of 19 (79%) of PPE patients showed one or more roentgenographic signs of volume overload. Receiver-operating-characteristic curves were constructed to determine optimum cut-off values of VPW and CT ratio associated with HPE. Hydrostatic pulmonary edema was found to correlate best using a VPW > 63 mm coupled to a CT ratio > 0.52 (p = 0.027). With this combination of objective criteria, radiologists' diagnostic accuracy could have been increased to 73%. We therefore conclude that measurements of CT ratio and VPW correlate with pulmonary artery occlusion pressure in supine, mechanically ventilated patients. Distinction of hydrostatic from permeability pulmonary edema is difficult using portable, supine CXRs, but readily assessed radiologic signs may contribute to the correct diagnosis.

Adult↗
PubMed1998

Radiographic assessment of hyperinflation: correlation with objective chest radiographic measurements and mechanical ventilator parameters.

BACKGROUND: Pulmonary barotrauma is a potentially fatal complication of positive pressure ventilation. We previously found that barotrauma occurred in patients with radiographic hyperinflation, but few objective data define the relationships among hyperinflation, objective chest radiograph (CXR) measurements, ventilator parameters, and development of barotrauma. OBJECTIVES: We sought (1) to assess the relationships among hyperinflation, objective CXR findings, mechanical ventilator parameters, and development of barotrauma. (2) To compare radiographic hyperinflation, ventilator parameters, and incidence of barotrauma in a current group of ICU patients with historical control subjects. SETTING: Medical and surgical ICU patients in a university hospital. DESIGN: Prospective blinded observational study; comparison of current series with historical control subjects. METHODS: One hundred two prospectively enrolled mechanically ventilated medical and surgical ICU patients each received portable supine CXRs that were reviewed independently by three radiologists who made objective measurements and subjectively determined the likelihood of hyperinflation. Ventilator parameters were recorded at the bedside at the time each CXR was obtained. CXR measurements and ventilator parameters were then related to the development of barotrauma during the course of ventilation and compared with findings of a prospective study at our institution 1 year earlier. RESULTS: Radiographically recognizable hyperinflation occurred in 18 of 102 mechanically ventilated ICU patients (18%) and correlated with lung length (24.7 vs 19.8 cm; p<0.05) and the anterior rib number that intersects the hemidiaphragm (5.4 vs 4.7; p<0.05). Patients with hyperinflation were ventilated at higher tidal volume per kilogram (VT/kg) (11.0 vs 9.4; p=0.0081), but peak airway pressure, plateau pressure, and positive end-expiratory pressure were similar. There were significant decreases in VT (810 vs 739 mL; p=0.015) and VT/kg (11.0 vs 10.1 mL/kg; p<0.001) in these mechanically ventilated ICU patients in comparison to hospital control subjects evaluated during the previous year. Paralleling these changes was a decrease in the frequency of CXR hyperinflation (p=0.003) and the incidence of ventilator-associated barotrauma (6.5% vs 0.98%; p=0.048). CONCLUSIONS: Ventilation at higher VT/kg is associated with a higher incidence of CXR hyperinflation. Radiographic hyperinflation is associated with lung length > or =24.7 cm and visualization of the sixth anterior rib. Patients with hyperinflation may be at greater risk for developing barotrauma or volutrauma. Ventilatory strategies utilizing lower volumes are associated with a lower incidence of such trauma in the current sample as compared with historical control subjects.

Adolescent↗