HypotensionNCT02907931
Carotid Doppler Ultrasound for the Measurement of Intravascular Volume Status
A study testing Point of Care Ultrasound in people with Hypotension and Sepsis, run by Yale University at 1 site in United States.
Trial summary
Ultrasound represents an attractive non-invasive method to assess hemodynamic status. Understanding dynamic changes in hemodynamics in situations such as hypovolemia, sepsis, and cardiogenic shock can potentially help improve patient care. Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Hypotension, Sepsis
- What is being tested?
- Point of Care Ultrasound
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 29 participants
- Where
- 1 siteUnited States
- Study dates
- Sep 2016to Jan 2020
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Generally healthy
- Able to provide informed consent
- Over 18 years of age
Who cannot join
- Non-English speaking or decisionaly impaired
- Significant medical illness (as determined by the study physician, JC)
- Taking vasoactive medications
- Older than 60 years of age
- Inability to lie flat for prolonged period
- Severe claustrophobia
- Pregnant
Trial locations and contacts
1 site in 1 country.
United States1 site
John B. Pierce Laboratory
New Haven, Connecticut, 06519
About this study
Official title: Carotid Doppler Ultrasound for the Measurement of Intravascular Volume Status During Lower Body Negative Pressure Simulation
Ultrasound represents an attractive non-invasive method to assess hemodynamic status. Understanding dynamic changes in hemodynamics in situations such as hypovolemia, sepsis, and cardiogenic shock can potentially help improve patient care. However, the inter-rater reliability and accuracy of how various ultrasound measurements reflect dynamic changes in physiology remains incompletely understood. Overall our aims are to investigate the use of ultrasound in a controlled setting, specifically using lower body negative pressure (LBNP), which can simulate hypovolemia at varied levels in human volunteers.
Aim 1: To determine the change in carotid blood flow (measured by velocity time integral, VTI) in subjects undergoing simulated hypovolemia at LBNP levels that precede vital sign changes.
Read more
Hypothesis: Carotid VTI will demonstrate significant changes that precede vital sign changes in simulated hypovolemia.
Aim 2: To compare transcranial color Doppler indices of cerebral blood flow with carotid blood flow, as assessed by VTI of the common carotid artery.
Hypothesis: Changes in transcranial color Doppler indices of cerebral blood flow will be mirrored by changes in carotid blood flow, indicating carotid VTI is an adequate surrogate for measuring cerebral blood flow in variable states of central hypovolemia. However, if cerebral blood flow remains more constant than carotid blood flow throughout varying levels of hypovolemia, our assumption is that cerebral autoregulation alters the relationship between carotid and cerebral blood flow. The more complex procedure of Transcranial Doppler ultrasound (TCD) must be performed to obtain valid assessments of cerebral blood flow.
Read the detailed description
Study Design: This is a prospective laboratory study using human volunteers.
Study Setting and Subjects: The study will take place in The John B. Pierce Laboratory where volunteers will be subjected to lower body negative pressure using the on-site LBNP chamber.
Protocol: Study subjects will be instructed to refrain from caffeine, alcohol, or cigarettes within 12 hours of the protocol, but will otherwise be allowed their routine oral intake prior to enrollment. The chamber is constructed of a sealed wood and acrylic box that is connected to a vacuum. Subjects will be placed into the chamber, which is sealed to the level of their pelvis by a neoprene skirt. Chamber pressure is transduced to an electronic digital manometer. The pressure in the chamber will reduced rapidly and held for 15-minute intervals at -5, -10, -15, and -20 mm Hg. If the subject becomes lightheaded, nauseated, or does not tolerate the test run in any way; negative pressure will be stopped.
Subjects will be monitored with continuous electrocardiogram monitoring, a standard automated blood pressure cuff, and a noninvasive beat-to-beat hemodynamic monitor (Finometer, Finapres Medical Systems, Amsterdam, The Netherlands). All carotid ultrasound measurements will be performed by specifically trained emergency physicians, using a Philips ultrasound machine (Philips Medical Systems, Andover, MA) equipped with phased and linear array probes programmed with Doppler capability. For transcranial Doppler imaging, we will use a 5- to 1-MHz sector array transducer and an Iu-22 ultrasound system (Philips Healthcare, Best, the Netherlands). Duplex sonography will be performed at the lower end of the frequency range (1-2 MHz) for better sound wave penetration of selected bone windows. For both the common carotid artery and transcranial portion of this study, we will obtain spectral Doppler waveform tracings and record measurements of corresponding vessel diameters. We will use data generated from software analysis of these spectral tracings to calculate hemodynamic parameters of interest to our study. Calculations are based on Bernoulli's principles of fluid dynamics.
- Conditions
- Hypotension, Sepsis
- Being tested
- Point of Care Ultrasound
- Keywords
- hemodynamics, ultrasonography
- Medical subject headings
- Hypotension, Sepsis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Point of Care UltrasoundOther
| Study group | Role | What they receive |
|---|---|---|
| Subjects | Experimental | Lower Body Negative Pressure Receives: Other: Point of Care Ultrasound |
What is being measured
The primary outcome is the main question the study is designed to answer.
changes in carotid blood flow (measured by velocity time integral, VTI) in subjects undergoing simulated hypovolemia
We will attach adhesive electrodes to your chest which allow us to monitor and record your vital signs. You will lie on your back on a table with the lower half of your body enclosed in a box. The box has a vacuum that creates suction and causes blood to pool in your legs and feet. Next you will do a Lower Body Negative Pressure test. For this test, you will lie with your lower body in the box while we apply increasing levels of suction, over 4 different intervals, lasting 2 minutes each. We will repeat the suction for longer times at each interval and obtain ultrasound images of blood vessels in your head and neck. Each interval may last up to 20 minutes for a total of up to 80 minutes time spent in the chamber.
Measured: over the course of 1-2 hours during which subjects will undergo incremental changes in lower body negative pressure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Sep 2016 (estimated)
- Study startSep 2016
- Primary completionJul 2018
- Study completionJan 2020
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (18)Papers the sponsor has linked to this study.
- Other trials for HypotensionStudies of the same condition, open and under way.
- More trials run by Yale UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 29 participants (actual)
Sponsor and investigators
- Lead sponsor
- Yale University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Jill C Crosby, MD, MHS, Principal investigator, Yale University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02907931
- Sponsor's protocol ID
- 1608018234
- Status last verified
- Jan 2020
- First submitted
- 14 Sep 2016
- Last updated
- 13 Jan 2020
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Marik PE. Iatrogenic salt water drowning and the hazards of a high central venous pressure. Ann Intensive Care. 2014 Jun 21;4:21. doi: 10.1186/s13613-014-0021-0. eCollection 2014.
PubMed 25110606Marik PE, Levitov A, Young A, Andrews L. The use of bioreactance and carotid Doppler to determine volume responsiveness and blood flow redistribution following passive leg raising in hemodynamically unstable patients. Chest. 2013 Feb 1;143(2):364-370. doi: 10.1378/chest.12-1274.
PubMed 22910834Mackenzie DC, Noble VE. Assessing volume status and fluid responsiveness in the emergency department. Clin Exp Emerg Med. 2014 Dec 31;1(2):67-77. doi: 10.15441/ceem.14.040. eCollection 2014 Dec.
PubMed 27752556Levitov A, Marik PE. Echocardiographic assessment of preload responsiveness in critically ill patients. Cardiol Res Pract. 2012;2012:819696. doi: 10.1155/2012/819696. Epub 2011 Sep 12.
PubMed 21918726Rivers E, Nguyen B, Havstad S, Ressler J, Muzzin A, Knoblich B, Peterson E, Tomlanovich M; Early Goal-Directed Therapy Collaborative Group. Early goal-directed therapy in the treatment of severe sepsis and septic shock. N Engl J Med. 2001 Nov 8;345(19):1368-77. doi: 10.1056/NEJMoa010307.
PubMed 11794169Dellinger RP, Levy MM, Rhodes A, Annane D, Gerlach H, Opal SM, Sevransky JE, Sprung CL, Douglas IS, Jaeschke R, Osborn TM, Nunnally ME, Townsend SR, Reinhart K, Kleinpell RM, Angus DC, Deutschman CS, Machado FR, Rubenfeld GD, Webb S, Beale RJ, Vincent JL, Moreno R; Surviving Sepsis Campaign Guidelines Committee including The Pediatric Subgroup. Surviving Sepsis Campaign: international guidelines for management of severe sepsis and septic shock, 2012. Intensive Care Med. 2013 Feb;39(2):165-228. doi: 10.1007/s00134-012-2769-8. Epub 2013 Jan 30.
PubMed 23361625Marik PE, Cavallazzi R, Vasu T, Hirani A. Dynamic changes in arterial waveform derived variables and fluid responsiveness in mechanically ventilated patients: a systematic review of the literature. Crit Care Med. 2009 Sep;37(9):2642-7. doi: 10.1097/CCM.0b013e3181a590da.
PubMed 19602972Blehar DJ, Glazier S, Gaspari RJ. Correlation of corrected flow time in the carotid artery with changes in intravascular volume status. J Crit Care. 2014 Aug;29(4):486-8. doi: 10.1016/j.jcrc.2014.03.025. Epub 2014 Apr 2.
PubMed 24930363Lamia B, Ochagavia A, Monnet X, Chemla D, Richard C, Teboul JL. Echocardiographic prediction of volume responsiveness in critically ill patients with spontaneously breathing activity. Intensive Care Med. 2007 Jul;33(7):1125-1132. doi: 10.1007/s00134-007-0646-7. Epub 2007 May 17.
PubMed 17508199Maizel J, Airapetian N, Lorne E, Tribouilloy C, Massy Z, Slama M. Diagnosis of central hypovolemia by using passive leg raising. Intensive Care Med. 2007 Jul;33(7):1133-1138. doi: 10.1007/s00134-007-0642-y. Epub 2007 May 17.
PubMed 17508202Stevens PM, Lamb LE. Effects of lower body negative pressure on the cardiovascular system. Am J Cardiol. 1965 Oct;16(4):506-15. doi: 10.1016/0002-9149(65)90027-5. No abstract available.
PubMed 5319567Cooke WH, Ryan KL, Convertino VA. Lower body negative pressure as a model to study progression to acute hemorrhagic shock in humans. J Appl Physiol (1985). 2004 Apr;96(4):1249-61. doi: 10.1152/japplphysiol.01155.2003.
PubMed 15016789Moore CL, Rose GA, Tayal VS, Sullivan DM, Arrowood JA, Kline JA. Determination of left ventricular function by emergency physician echocardiography of hypotensive patients. Acad Emerg Med. 2002 Mar;9(3):186-93. doi: 10.1111/j.1553-2712.2002.tb00242.x.
PubMed 11874773Moore CL, Tham ET, Samuels KJ, McNamara RL, Galante NJ, Stachenfeld N, Shelley K, Dziura J, Silverman DG. Tissue Doppler of early mitral filling correlates with simulated volume loss in healthy subjects. Acad Emerg Med. 2010 Nov;17(11):1162-8. doi: 10.1111/j.1553-2712.2010.00906.x.
PubMed 21175513Stolz LA, Mosier JM, Gross AM, Douglas MJ, Blaivas M, Adhikari S. Can emergency physicians perform common carotid Doppler flow measurements to assess volume responsiveness? West J Emerg Med. 2015 Mar;16(2):255-9. doi: 10.5811/westjem.2015.1.24301. Epub 2015 Feb 26.
PubMed 25834666
Study at a glance
From the registry record, last updated by the sponsor on 13 Jan 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Carotid Doppler Ultrasound for the Measurement of Intravascular Volume Status During Lower Body Negative Pressure Simulation
- ClinicalTrials.gov ID
- NCT02907931
- Acronym / sponsor ID
- 1608018234
- Conditions
- Hypotension, Sepsis
- Keywords
- hemodynamics, ultrasonography
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 29 participants (actual)
- Lead sponsor
- Yale UniversityUniversity, hospital or other
- Study start
- Sep 2016
- Primary completion
- Jul 2018 (actual)
- Study completion
- Jan 2020 (actual)
- First posted
- 20 Sep 2016 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Ultrasound represents an attractive non-invasive method to assess hemodynamic status. Understanding dynamic changes in hemodynamics in situations such as hypovolemia, sepsis, and cardiogenic shock can potentially help improve patient care. However, the inter-rater reliability and accuracy of how various ultrasound measurements reflect dynamic changes in physiology remains incompletely understood. Overall our aims are to investigate the use of ultrasound in a controlled setting, specifically using lower body negative pressure (LBNP), which can simulate hypovolemia at varied levels in human volunteers.
Aim 1: To determine the change in carotid blood flow (measured by velocity time integral, VTI) in subjects undergoing simulated hypovolemia at LBNP levels that precede vital sign changes.
Hypothesis: Carotid VTI will demonstrate significant changes that precede vital sign changes in simulated hypovolemia.
Aim 2: To compare transcranial color Doppler indices of cerebral blood flow with carotid blood flow, as assessed by VTI of the common carotid artery.
Hypothesis: Changes in transcranial color Doppler indices of cerebral blood flow will be mirrored by changes in carotid blood flow, indicating carotid VTI is an adequate surrogate for measuring cerebral blood flow in variable states of central hypovolemia. However, if cerebral blood flow remains more constant than carotid blood flow throughout varying levels of hypovolemia, our assumption is that cerebral autoregulation alters the relationship between carotid and cerebral blood flow. The more complex procedure of Transcranial Doppler ultrasound (TCD) must be performed to obtain valid assessments of cerebral blood flow.
Detailed description
Study Design: This is a prospective laboratory study using human volunteers.
Study Setting and Subjects: The study will take place in The John B. Pierce Laboratory where volunteers will be subjected to lower body negative pressure using the on-site LBNP chamber.
Protocol: Study subjects will be instructed to refrain from caffeine, alcohol, or cigarettes within 12 hours of the protocol, but will otherwise be allowed their routine oral intake prior to enrollment. The chamber is constructed of a sealed wood and acrylic box that is connected to a vacuum. Subjects will be placed into the chamber, which is sealed to the level of their pelvis by a neoprene skirt. Chamber pressure is transduced to an electronic digital manometer. The pressure in the chamber will reduced rapidly and held for 15-minute intervals at -5, -10, -15, and -20 mm Hg. If the subject becomes lightheaded, nauseated, or does not tolerate the test run in any way; negative pressure will be stopped.
Subjects will be monitored with continuous electrocardiogram monitoring, a standard automated blood pressure cuff, and a noninvasive beat-to-beat hemodynamic monitor (Finometer, Finapres Medical Systems, Amsterdam, The Netherlands). All carotid ultrasound measurements will be performed by specifically trained emergency physicians, using a Philips ultrasound machine (Philips Medical Systems, Andover, MA) equipped with phased and linear array probes programmed with Doppler capability. For transcranial Doppler imaging, we will use a 5- to 1-MHz sector array transducer and an Iu-22 ultrasound system (Philips Healthcare, Best, the Netherlands). Duplex sonography will be performed at the lower end of the frequency range (1-2 MHz) for better sound wave penetration of selected bone windows. For both the common carotid artery and transcranial portion of this study, we will obtain spectral Doppler waveform tracings and record measurements of corresponding vessel diameters. We will use data generated from software analysis of these spectral tracings to calculate hemodynamic parameters of interest to our study. Calculations are based on Bernoulli's principles of fluid dynamics.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Subjects | Experimental | Other: Point of Care UltrasoundLower Body Negative Pressure |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Generally healthy
- Able to provide informed consent
- Over 18 years of age
Key exclusion criteria (7 listed)
- Non-English speaking or decisionaly impaired
- Significant medical illness (as determined by the study physician, JC)
- Taking vasoactive medications
- Older than 60 years of age
- Inability to lie flat for prolonged period
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Point of Care Ultrasound | Other | Subjects |
Primary outcome
changes in carotid blood flow (measured by velocity time integral, VTI) in subjects undergoing simulated hypovolemia
Time frame: over the course of 1-2 hours during which subjects will undergo incremental changes in lower body negative pressure
We will attach adhesive electrodes to your chest which allow us to monitor and record your vital signs. You will lie on your back on a table with the lower half of your body enclosed in a box. The box has a vacuum that creates suction and causes blood to pool in your legs and feet. Next you will do a Lower Body Negative Pressure test. For this test, you will lie with your lower body in the box while we apply increasing levels of suction, over 4 different intervals, lasting 2 minutes each. We will repeat the suction for longer times at each interval and obtain ultrasound images of blood vessels in your head and neck. Each interval may last up to 20 minutes for a total of up to 80 minutes time spent in the chamber.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Jan 2020.
- Background: PubMed 25110606Marik PE. Iatrogenic salt water drowning and the hazards of a high central venous pressure. Ann Intensive Care. 2014 Jun 21;4:21. doi: 10.1186/s13613-014-0021-0. eCollection 2014.
- Background: PubMed 22910834Marik PE, Levitov A, Young A, Andrews L. The use of bioreactance and carotid Doppler to determine volume responsiveness and blood flow redistribution following passive leg raising in hemodynamically unstable patients. Chest. 2013 Feb 1;143(2):364-370. doi: 10.1378/chest.12-1274.
- Background: PubMed 27752556Mackenzie DC, Noble VE. Assessing volume status and fluid responsiveness in the emergency department. Clin Exp Emerg Med. 2014 Dec 31;1(2):67-77. doi: 10.15441/ceem.14.040. eCollection 2014 Dec.
- Background: PubMed 21918726Levitov A, Marik PE. Echocardiographic assessment of preload responsiveness in critically ill patients. Cardiol Res Pract. 2012;2012:819696. doi: 10.1155/2012/819696. Epub 2011 Sep 12.
- Background: PubMed 11794169Rivers E, Nguyen B, Havstad S, Ressler J, Muzzin A, Knoblich B, Peterson E, Tomlanovich M; Early Goal-Directed Therapy Collaborative Group. Early goal-directed therapy in the treatment of severe sepsis and septic shock. N Engl J Med. 2001 Nov 8;345(19):1368-77. doi: 10.1056/NEJMoa010307.
- Background: PubMed 23361625Dellinger RP, Levy MM, Rhodes A, Annane D, Gerlach H, Opal SM, Sevransky JE, Sprung CL, Douglas IS, Jaeschke R, Osborn TM, Nunnally ME, Townsend SR, Reinhart K, Kleinpell RM, Angus DC, Deutschman CS, Machado FR, Rubenfeld GD, Webb S, Beale RJ, Vincent JL, Moreno R; Surviving Sepsis Campaign Guidelines Committee including The Pediatric Subgroup. Surviving Sepsis Campaign: international guidelines for management of severe sepsis and septic shock, 2012. Intensive Care Med. 2013 Feb;39(2):165-228. doi: 10.1007/s00134-012-2769-8. Epub 2013 Jan 30.
- Background: PubMed 19602972Marik PE, Cavallazzi R, Vasu T, Hirani A. Dynamic changes in arterial waveform derived variables and fluid responsiveness in mechanically ventilated patients: a systematic review of the literature. Crit Care Med. 2009 Sep;37(9):2642-7. doi: 10.1097/CCM.0b013e3181a590da.
- Background: PubMed 24930363Blehar DJ, Glazier S, Gaspari RJ. Correlation of corrected flow time in the carotid artery with changes in intravascular volume status. J Crit Care. 2014 Aug;29(4):486-8. doi: 10.1016/j.jcrc.2014.03.025. Epub 2014 Apr 2.
- Background: PubMed 17508199Lamia B, Ochagavia A, Monnet X, Chemla D, Richard C, Teboul JL. Echocardiographic prediction of volume responsiveness in critically ill patients with spontaneously breathing activity. Intensive Care Med. 2007 Jul;33(7):1125-1132. doi: 10.1007/s00134-007-0646-7. Epub 2007 May 17.
- Background: PubMed 17508202Maizel J, Airapetian N, Lorne E, Tribouilloy C, Massy Z, Slama M. Diagnosis of central hypovolemia by using passive leg raising. Intensive Care Med. 2007 Jul;33(7):1133-1138. doi: 10.1007/s00134-007-0642-y. Epub 2007 May 17.
- Background: PubMed 5319567Stevens PM, Lamb LE. Effects of lower body negative pressure on the cardiovascular system. Am J Cardiol. 1965 Oct;16(4):506-15. doi: 10.1016/0002-9149(65)90027-5. No abstract available.
- Background: PubMed 15016789Cooke WH, Ryan KL, Convertino VA. Lower body negative pressure as a model to study progression to acute hemorrhagic shock in humans. J Appl Physiol (1985). 2004 Apr;96(4):1249-61. doi: 10.1152/japplphysiol.01155.2003.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Jill C Crosby, MD, MHS principal investigator
Yale University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Point of Care Ultrasound in people with Hypotension and Sepsis, run by Yale University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 13 Jan 2020. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
changes in carotid blood flow (measured by velocity time integral, VTI) in subjects undergoing simulated hypovolemia (time frame: over the course of 1-2 hours during which subjects will undergo incremental changes in lower body negative pressure). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02907931, which also lists 18 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Jan 2020.