Fluoroscopy time is not accurate as a surrogate for radiation exposure

Vascular ◽  
2017 ◽  
Vol 25 (5) ◽  
pp. 466-471 ◽  
Author(s):  
Edvard Skripochnik ◽  
Shang A Loh
Keyword(s):  
Radiation Exposure ◽  
Medical Center ◽  
Pearson Correlation ◽  
Academic Medical Center ◽  
Surrogate Marker ◽  
Correlation Coefficients ◽  
Frame Rate ◽  
Fluoroscopy Time ◽  
Poor Correlation ◽  
Dose Area Product

Objective The Food and Drug Administration and the Vascular Quality Initiative still utilize fluoroscopy time as a surrogate marker for procedural radiation exposure. This study demonstrates that fluoroscopy time does not accurately represent radiation exposure and that dose area product and air kerma are more appropriate measures. Methods Lower extremity endovascular interventions ( N = 145) between 2013 and 2015 performed at an academic medical center on a Siemens Artis-Zee floor mounted c-arm were identified. Data was collected from the summary sheet after every case. Scatter plots with Pearson correlation coefficients were created. A strong correlation was indicated by an r value approaching 1. Results Overall mean AK and DAP was 380.27 mGy and 4919.2 µGym2. There was a poor correlation between fluoroscopy time and total AK or DAP ( r = 0.27 and 0.32). Total DAP was strongly correlated to cine DAP and fluoroscopy DAP ( r = 0.92 vs. 0.84). The number of DSA runs and average frame rate did not affect AK or DAP levels. Mean magnification level was significantly correlated with total AK ( r = 0.53). Conclusions Fluoroscopy time shows minimal correlation with radiation delivered and therefore is a poor surrogate for radiation exposure during fluoroscopy procedures. DAP and AK are more suitable markers to accurately gauge radiation exposure.

Using 7.5 frames per second reduces radiation exposure in lower extremity peripheral vascular interventions

Vascular ◽  
2014 ◽  
Vol 23 (3) ◽  
pp. 240-244 ◽  
Author(s):  
Nuri I Akkus ◽  
George S Mina ◽  
Abdulrahman Abdulbaki ◽  
Fereidoon Shafiei ◽  
Neeraj Tandon
Keyword(s):  
Radiation Dose ◽  
Radiation Exposure ◽  
Success Rate ◽  
Frame Rate ◽  
Fluoroscopy Time ◽  
Peripheral Vascular ◽  
Dose Area Product ◽  
Group A ◽  
Group B ◽  
Area Product

Background Peripheral vascular interventions can be associated with significant radiation exposure to the patient and the operator. Objective In this study, we sought to compare the radiation dose between peripheral vascular interventions using fluoroscopy frame rate of 7.5 frames per second (fps) and those performed at the standard 15 fps and procedural outcomes. Methods We retrospectively collected data from consecutive 87 peripheral vascular interventions performed during 2011 and 2012 from two medical centers. The patients were divided into two groups based on fluoroscopy frame rate; 7.5 fps (group A, n = 44) and 15 fps (group B, n = 43). We compared the demographic, clinical, procedural characteristics/outcomes, and radiation dose between the two groups. Radiation dose was measured as dose area product in micro Gray per meter square. Results Median dose area product was significantly lower in group A (3358, interquartile range (IQR) 2052–7394) when compared to group B (8812, IQR 4944–17,370), p < 0.001 with no change in median fluoroscopy time in minutes (18.7, IQR 11.1–31.5 vs. 15.7, IQR 10.1–24.1), p = 0.156 or success rate (93.2% vs. 95.3%), p > 0.999. Conclusion Using fluoroscopy at the rate of 7.5 fps during peripheral vascular interventions is associated with lower radiation dose compared to the standard 15 fps with comparable success rate without associated increase in the fluoroscopy time or the amount of the contrast used. Therefore, using fluoroscopy at the rate of 7.5 fps should be considered in peripheral vascular interventions.

Abstract P257: Getting to the Golden Hour: Correlating “Door-To” Times with 60-Minute Administration of tPA in an Academic Medical Center

2011 ◽  
Vol 4 (suppl_2) ◽  
Author(s):  
Ann M Leonhardt ◽  
Curtis G Benesch ◽  
Kate C Young
Keyword(s):  
Medical Center ◽  
Academic Medical Center ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Time Frame ◽  
Arrival Times ◽  
Golden Hour ◽  
Stroke Team ◽  
Time Standards ◽  
Scheduling Protocols

Introduction: The efficacy of intravenous tPA for the treatment of acute stroke diminishes over time. The AHA/ASA and NINDS recommend a goal door to needle time of 60 minutes or less. Objective: Identify potential barriers to tPA administration within 60 minutes of arrival. Methods: Retrospective review of tPA adsinistration using “Get With the Guidelines” (GWTG) and institutional records from January 1, 2009 through December 31, 2010 (n=100). Spearman rank correlation coefficients were calculated for the NINDS recommended time standards, age and NIH Stroke Scale (NIHSS) score. We used a receiver-operator curve (ROC) to identify the door to CT time predictive of tPA administration ≤ 60 minutes. Results: Median door to physician, door to CT, and door to stroke team times were within the recommended goals. Door to CT (ρ=0.53, p<0.0001), and door to stroke team (ρ=0.33, p<0.01) times were positively correlated with door to tPA times. Last known well to arrival (ρ= -0.28, p<0.01) and NIHSS (ρ= -0.32, p<0.01) were negatively correlated with door to tPA times; patients with higher NIHSS and longer last-known-well to arrival times received tPA in a shorter time frame. Age and door to physician time were not correlated with tPA treatment times. After adjusting for the other benchmarks and NIHSS, only door to CT remained significantly correlated with door to IV tPA (partial correlation coefficient=0.40, p<0.001). The ROC curve showed that a goal time of 20 minutes or less for door to CT initiation had the best sensitivity and specificity for predicting tPA administration within 60 minutes. Conclusion: In keeping with the recommended time goals, median times for the intermediate steps were within target. Our median tPA times, however, did not meet the 60 minute goal. Door to CT initiation was the variable that most strongly correlated with door to needle times. Process issues such as order entry and scheduling protocols may be barriers to obtaining CT within the 20 minute time frame identified by our analysis. Other barriers after the CT scan is obtained must be identified to facilitate faster tPA administration. Further evaluation of these factors is warranted to better ensure the timely delivery of tPA to stroke patients, thereby improving patient outcomes.

Sustained Reduction of Ventilator-Associated Pneumonia Rates Using Real-Time Course Correction With a Ventilator Bundle Compliance Dashboard

2015 ◽  
Vol 36 (11) ◽  
pp. 1261-1267 ◽  
Author(s):  
Thomas R. Talbot ◽  
Devin Carr ◽  
C. Lee Parmley ◽  
Barbara J. Martin ◽  
Barbara Gray ◽  
...  
Keyword(s):  
Real Time ◽  
Program Implementation ◽  
Time Course ◽  
Medical Center ◽  
Pearson Correlation ◽  
Academic Medical Center ◽  
Ventilator Associated Pneumonia ◽  
Interrupted Time Series Analysis ◽  
Adherence Assessment ◽  
Bundle Compliance

BACKGROUNDThe effectiveness of practice bundles on reducing ventilator-associated pneumonia (VAP) has been questioned.OBJECTIVETo implement a comprehensive program that included a real-time bundle compliance dashboard to improve compliance and reduce ventilator-associated complications.DESIGNBefore-and-after quasi-experimental study with interrupted time-series analysis.SETTINGAcademic medical center.METHODSIn 2007 a comprehensive institutional ventilator bundle program was developed. To assess bundle compliance and stimulate instant course correction of noncompliant parameters, a real-time computerized dashboard was developed. Program impact in 6 adult intensive care units (ICUs) was assessed. Bundle compliance was noted as an overall cumulative bundle adherence assessment, reflecting the percentage of time all elements were concurrently in compliance for all patients.RESULTSThe VAP rate in all ICUs combined decreased from 19.5 to 9.2 VAPs per 1,000 ventilator-days following program implementation (P<.001). Bundle compliance significantly increased (Z100 score of 23% in August 2007 to 83% in June 2011 [P<.001]). The implementation resulted in a significant monthly decrease in the overall ICU VAP rate of 3.28/1,000 ventilator-days (95% CI, 2.64–3.92/1,000 ventilator-days). Following the intervention, the VAP rate decreased significantly at a rate of 0.20/1,000 ventilator-days per month (95% CI, 0.14–0.30/1,000 ventilator-days per month). Among all adult ICUs combined, improved bundle compliance was moderately correlated with monthly VAP rate reductions (Pearson correlation coefficient, −0.32).CONCLUSIONA prevention program using a real-time bundle adherence dashboard was associated with significant sustained decreases in VAP rates and an increase in bundle compliance among adult ICU patients.Infect. Control Hosp. Epidemiol. 2015;36(11):1261–1267

scholarly journals Two Data-Driven Approaches to Identifying the Spectrum of Problematic Opioid Use: A Pilot Study within a Chronic Pain Cohort

2021 ◽  
Author(s):  
Lori Schirle ◽  
Alvin D Jeffery ◽  
Ali Yaqoob ◽  
Sandra Sanchez-Roige ◽  
David C. Samuels
Keyword(s):  
Language Processing ◽  
Medical Center ◽  
Academic Medical Center ◽  
Correlation Coefficients ◽  
Pilot Project ◽  
Data Driven ◽  
Risk Scores ◽  
Opioid Use ◽  
Academic Medical ◽  
Manual Review

Background: Although electronic health records (EHR) have significant potential for the study of opioid use disorders (OUD), detecting OUD in clinical data is challenging. Models using EHR data to predict OUD often rely on case/control classifications focused on extreme opioid use. There is a need to expand this work to characterize the spectrum of problematic opioid use. Methods: Using a large academic medical center database, we developed 2 data-driven methods of OUD detection: (1) a Comorbidity Score developed from a Phenome-Wide Association Study of phenotypes associated with OUD and (2) a Text-based Score using natural language processing to identify OUD-related concepts in clinical notes. We evaluated the performance of both scores against a manual review with correlation coefficients, Wilcoxon rank sum tests, and area-under the receiver operating characteristic curves. Records with the highest Comorbidity and Text-based scores were re-evaluated by manual review to explore discrepancies. Results: Both the Comorbidity and Text-based OUD risk scores were significantly elevated in the patients judged as High Evidence for OUD in the manual review compared to those with No Evidence (p = 1.3E-5 and 1.3E-6, respectively). The risk scores were positively correlated with each other (rho = 0.52, p < 0.001). AUCs for the Comorbidity and Text-based scores were high (0.79 and 0.76, respectively). Follow-up manual review of discrepant findings revealed strengths of data-driven methods over manual review, and opportunities for improvement in risk assessment. Conclusion: Risk scores comprising comorbidities and text offer differing but synergistic insights into characterizing problematic opioid use. This pilot project establishes a foundation for more robust work in the future.

scholarly journals Sympathetic stimulation increases serum lactate concentrations in patients admitted with sepsis: implications for resuscitation strategies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nikhil Jagan ◽  
Lee E. Morrow ◽  
Ryan W. Walters ◽  
Robert W. Plambeck ◽  
Tej M. Patel ◽  
...  
Keyword(s):  
Medical Center ◽  
Academic Medical Center ◽  
Surrogate Marker ◽  
Lactate Production ◽  
Severity Of Illness ◽  
Serum Lactate ◽  
Sympathetic Stimulation ◽  
Arterial Blood ◽  
Academic Medical ◽  
Lactate Levels

Abstract Background Diametrically opposed positions exist regarding the deleterious effects of elevated lactate. There are data suggesting that it is a detrimental proxy for tissue hypoperfusion and anaerobic metabolism in sepsis and an alternative viewpoint is that some of the hyperlactatemia produced maybe adaptive. This study was conducted to explore the relationship between serum lactate levels, mean arterial blood pressure (MAP), and sympathetic stimulation in patients with sepsis. Methods Retrospective analysis of prospectively collected clinical data from four community-based hospitals and one academic medical center. 8173 adults were included. Heart rate (HR) was used as a surrogate marker of sympathetic stimulation. HR, MAP, and lactate levels were measured upon presentation. Results MAP and HR interacted to affect lactate levels with the highest levels observed in patients with low MAP and high HR (3.6 mmol/L) and the lowest in patients with high MAP and low HR (2.2 mmol/L). The overall mortality rate was 12.4%. Each 10 beats/min increase in HR increased the odds of death 6.0% (95% CI 2.6% to 9.4%), each 1 mmol/L increase in lactate increased the odds of death 20.8% (95% CI 17.4% to 24.2%), whereas each 10 mmHg increase in MAP reduced the odds of death 12.3% (95% CI 9.2% to 15.4%). However, HR did not moderate or mediate the association between lactate and death. Conclusions In septic patients, lactate production was associated with increased sympathetic activity (HR ≥ 90) and hypotension (MAP < 65 mmHg) and was a significant predictor of mortality. Because HR, lactate, and MAP were associated with mortality, our data support the present strategy of using these measurements to gauge severity of illness upon presentation. Since HR did not moderate or mediate the association between lactate and death, criticisms alleging that lactate caused by sympathetic stimulation is adaptive (i.e., less harmful) do not appear substantiated.

Analysis of Radiation Exposure during Endovascular Aneurysm Repair

2012 ◽  
Vol 78 (10) ◽  
pp. 1029-1032 ◽  
Author(s):  
Michael Butler ◽  
Madhukar S. Patel ◽  
Samuel E. Wilson
Keyword(s):  
Radiation Exposure ◽  
Endovascular Aneurysm Repair ◽  
Abdominal Aortic Aneurysm Repair ◽  
Fluoroscopy Time ◽  
Potential Hazard ◽  
Dose Area Product ◽  
Contrast Volume ◽  
Using Data ◽  
Area Product ◽  
Aneurysm Repair

Endovascular aneurysm repair (EVAR) is now the preferred procedure for abdominal aortic aneurysm repair. As a result of the need for fluoroscopy during EVAR, radiation exposure is a potential hazard. We studied the quantity of radiation delivered during EVAR to identify risks for excessive exposure. Fluoroscopy time, contrast volume used, and procedural details were recorded prospectively during EVARs. Using data collected from similar EVARs, an equation was derived to calculate approximate dose-area product (DAP) from fluoroscopy time. DAP values were then compared between procedures in which a relevant postdeployment procedure (PDP) was necessary intraoperatively with those without. Clinical data on 17 patients were collected. The mean age of patients was 68 (±9) years. Fluoroscopy times and approximate DAP values were found to be significantly higher in the seven patients with a PDP compared with the 10 patients without an intraoperative PDP (31.2 [±9.6] vs 22.7 [±6.0] minutes, P = 0.033 and 537 [±165] vs 390 [±103] Gy-cm2, P = 0.033, respectively). The average amount of contrast volume used was not significantly different between groups. Radiation emitted during EVARs with PDPs was significantly greater relative to those without PDPs. Device design and operators should thus aim to decrease PDPs and to minimize fluoroscopy time.

scholarly journals Risk of ionizing radiation exposure from CT scans in the Neuro ICU - a patient safety blind spot?

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2489
Author(s):  
Avinash B. Kumar ◽  
Roy C. Neeley
Keyword(s):  
Mechanical Ventilation ◽  
Patient Safety ◽  
Ionizing Radiation ◽  
Radiation Exposure ◽  
Medical Center ◽  
Academic Medical Center ◽  
Ct Scans ◽  
Academic Medical ◽  
The Mean ◽  
Ct Studies

Introduction: The exposure to ionizing radiation has increased significantly with the wide availability of computed tomography (CT) scans and portable imaging technology. We examine the pattern of use of inpatient diagnostic imaging and radiation exposure in the neuro-intensive care unit (Neuro ICU, N-ICU) patient population at a large academic medical center. Methods: We retrospectively evaluated all patients admitted to the Neuro ICU at our academic medical center from January 1 to December 31, 2013. The number and type of CT studies was collected, and the corresponding estimated radiation dose was calculated. We limited the evaluation to CT scans, which accounts for the majority of radiation exposure. Data were electronically collected and cross-referenced to the patients’ electronic medical records (EMR) and radiology records. Radiation dose estimates were calculated based on published reference values and conversion factors (CT head (2mSv)), CT angiography of the head and neck (7-10 mSv), Ct Chest /Abd/pelvis ( 10 mSv), CT cerebral perfusion analysis (3.3 mSv). Results: In the calendar year 2013, we had a total of 2353 admission encounters (F=1078). The mean age on admission was 56.55Y ± 16.7. The mean length of ICU stay was 6.3 days. Mechanical ventilation was initiated on 420 patients with a mean length on mechanical ventilation 5.09 days. 2028 CT scans were completed of which approximately 60% were head CT without contrast (n=1209). 379 patients had multiple CT studies. The mean number of studies was 3.8 ± 2. The number of patients with more thanthree3 studies during their ICU stay was 159.  The maximum number of studies on a single patient was 21. Conclusion: Patients in the Neuro ICU are at a risk for significant exposure to ionizing radiation. Radiation exposure must be factored into the culture of quality and patient safety in the ICU.

Abstract 17014: Getting to Zero: Impact of Electroanatomical Mapping on Fluoroscopy Use in Pediatric Catheter Ablation

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Bradley C Clark ◽  
Kohei Sumihara ◽  
Robert McCarter ◽  
Charles I Berul ◽  
Jeffrey P Moak
Keyword(s):  
Radiation Dose ◽  
Radiation Exposure ◽  
Imaging Techniques ◽  
Statistical Significance ◽  
Accessory Pathway ◽  
Analysis Of Covariance ◽  
Fluoroscopy Time ◽  
Normal Heart ◽  
Dose Area Product ◽  
Zero Fluoroscopy

Introduction: Over the past several years, alternative imaging techniques including electroanatomic mapping systems such as CARTO®3 (C3) have been developed to improve anatomic resolution and potentially limit radiation exposure in electrophysiology (EP) procedures. We retrospectively examined the effect of the introduction of C3 on patient radiation exposure during EP studies and ablation procedures at a children’s hospital. Methods: All patients that underwent EP and ablation procedures between January 2012 and November 2014 were included; demographic information, fluoroscopy time in minutes (FT), total radiation dose in mGy (RAD), and dose-area product in μGy/m2 (DAP) were collected. Patients were stratified by time period (before vs. after C3 introduction), structural group (normal heart, congenital heart disease (CHD), and those with normal cardiac anatomy requiring trans-septal (TS) access), and arrhythmia diagnosis (Accessory Pathway (AP), AV Nodal Reentry Tachycardia (AVNRT), atrial, or ventricular arrhythmia). Mean values were compared using a single sample t-test, as well as analysis of covariance to control for age, weight, and arrhythmia diagnosis. Results: Mean FT decreased after the introduction of C3 in patients with normal hearts (p<0.001), AP (p<0.001), AVNRT (p=0.002), and CHD (p=0.007). After controlling for age, weight, and arrhythmia diagnosis, there was a statistically significant decrease in FT in all three groups (normal heart, CHD and TS), in RAD in the TS group, and in DAP in both the normal heart and TS groups. In all other groups, there was a trend towards decreased RAD and DAP, but they did not reach statistical significance. After the introduction of C3, zero fluoroscopy was achieved in 18/66 (27%) and ≤ 1 minute of FT in 28/66 (42%) of ablation procedures in patients with normal hearts. Conclusions: We have shown a decrease in all metrics that measure radiation exposure when comparing the time periods before and after the introduction of C3, secondary to reducing fluoroscopy time, fluoroscopic pulse rate and radiation dose per pulse. Further refinements are still needed to decrease radiation exposure towards the goal of zero fluoroscopy, but this cannot be achieved without thinking beyond fluoroscopy time.

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