Hemodynamic Optimization By Non-Invasive Determination Of Cardiac Output In Critically Ill Patients

Hypotension Clinical Trial

Official title:

HEMODYNAMIC OPTIMIZATION BY NON-INVASIVE DETERMINATION OF CARDIAC OUTPUT IN CRITICALLY ILL PATIENTS: A RANDOMIZED, CONTROLLED TRIAL

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01309724
• Other study ID #: 09-1074
• Status: Completed
• Phase: N/A
• First received: March 2, 2011
• Last updated: March 3, 2011
• Start date: January 2010
• Est. completion date: December 2010

Study information

• Verified date: March 2011
• Source: Washington University School of Medicine
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

Inadequate identification of and subsequent delayed therapy for patients with hypoperfusion (including hypovolemia, congestive heart failure and sepsis) is a common problem faced by physicians and intensivists caring for critically ill patients. Bedside clinical assessment is notoriously inaccurate in diagnosing complex etiologies of hemodynamic disturbances and in deciding on the appropriate therapy. Invasive techniques which are often required to guide diagnosis and therapy have significant risks associated with them, are costly, and are time consuming. New technology has been developed that allows for instantaneous, noninvasive monitoring of key hemodynamic parameters, like stroke volume, peak velocity and cardiac output. This new technology has the potential to improve recognition of the etiology of hemodynamic disturbances and assist the clinician in optimizing therapy based on changes in hemodynamic parameters. There is significant potential for this to be translated into improved outcomes in critically ill patients, but this has never been studied.

Description:

Patients with life-threatening hypotension are commonly cared for in intensive care units (ICUs). Pathophysiologic perturbations due to disease states such as sepsis, hypovolemia, and congestive heart failure may lead to tissue hypoxia, a critical development which precedes multi-organ failure and death. Not only is it difficult to rapidly identify patients heading down this path, but the execution of effective hemodynamic resuscitation to slow or reverse this process is challenging.

A cornerstone of hemodynamic resuscitation is volume administration. The goal of volume administration is to maximize cardiac output, and thereby systemic oxygen delivery, by optimizing cardiac preload. Bedside clinical assessment is inadequate for judging whether or not this goal has been achieved. Invasive techniques, such as central venous pressure (CVP) monitoring and pulmonary artery catheterization, carry risks, are costly and time-consuming, and may yield misleading data. Doppler ultrasound-based technology has been developed that allows for instantaneous, non-invasive monitoring of key hemodynamic parameters, such as cardiac output. This technology may facilitate determining the etiology of hemodynamic disturbances and assist the clinician in optimizing therapy based on changes in hemodynamic parameters. This randomized, controlled trial was designed to determine the impact of a volume resuscitation protocol, guided by non-invasive Doppler ultrasound technology, on outcomes in medical ICU patients with vasopressor-dependent hypotension.

Materials and methods:

Patient Population:

Study participants were recruited between January 19, 2010 and December 26, 2010 from two medical ICUs at Barnes-Jewish Hospital, a 1252-bed urban teaching hospital. The Washington University School of Medicine Human Research Protection Office approved the study, and informed consent was obtained from participants or their authorized representatives. Inclusion criteria were age ≥18 years; administration of vasopressors, defined as a continuous infusion of norepinephrine at a dose >5 mcg/min, dopamine ≥5 mcg/kg/min or any dose of another vasopressor; and passage of <18 hours since initiation of vasopressors at doses specified above. Exclusion criteria were hemorrhagic shock, need for immediate surgery, imminent risk of death in the next 48 hours (as judged by the attending ICU physician), level of care decision that precluded implementation of the study protocol, enrollment in any other clinical study, and pregnancy.

Study Protocol:

Subjects were assigned to treatment groups using blocked randomization to receive either volume resuscitation guided by the ultrasound cardiac output monitor (USCOM; USCOM Ltd., Sydney, Australia) or observation. The USCOM is a non-invasive device that uses continuous-wave Doppler ultrasound measurements of blood flow in the ascending aorta or pulmonary artery to estimate stroke volume (SV). Prior to the beginning of the study, one of the study investigators (LMD) underwent a supervised training period with the USCOM in 50 patients to insure reproducibility of the obtained measurements. Subjects randomized to the intervention group underwent a baseline USCOM measurement of SV by a single operator (LMD), followed by a pressurized infusion of 1 L of normal saline (NS) over approximately 15 minutes, after which the SV measurement was repeated. If the SV increased by ≥15%, the patient was deemed volume-responsive, and another 1 L NS bolus was administered. This process was repeated until the SV did not increase by ≥15%, two hours had elapsed since study enrollment, or 4 L of NS had been infused, whichever occurred first. With the exception of initial fluid management in the intervention group, as described above, use of all diagnostic and treatment modalities were at the discretion of the ICU physicians. Subjects in the control group underwent no intervention; ongoing care was carried out at the discretion of the ICU physicians. ICU physicians were unaware of subjects' group assignments and the USCOM data acquired in the intervention group.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 92
• Est. completion date: December 2010
• Est. primary completion date: December 2010
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Age 18 yrs or greater

• Administration of vasopressors, defined as a continuous infusion of norepinephrine at a dose >5 mcg/min, dopamine =5 mcg/kg/min or any dose of another vasopressor

• Passage of <18 hours since initiation of vasopressors at doses specified above

Exclusion Criteria:

• Hemorrhagic shock

• Need for immediate surgery

• Imminent risk of death in the next 48 hours (as judged by the attending ICU physician)

• Level of care decision that precluded implementation of the study protocol

• Enrollment in any other clinical study

• Pregnancy

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Critical Illness
• Hypotension

Intervention

Other:
• USCOM-guided fluid administration
Patients in the intervention group underwent hemodynamic measurements with the ultrasound cardiac output monitor. Based on these measurements, patients were guided through a fluid resuscitation protocol.

Locations

Country	Name	City	State
United States	Barnes-Jewish Hospital	Saint Louis	Missouri

Sponsors (1)

Lead Sponsor	Collaborator
Washington University School of Medicine

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Time on vasopressors, measured during the 48 hours after study enrollment		48 hours after study enrollment	No
Secondary	ICU length of stay		At one month (average)	No
Secondary	Hospital length of stay		At one month (average)	No
Secondary	Duration of mechanical ventilation		At one month (average)	No
Secondary	Development of acute renal failure		At one month (average)	No
Secondary	Invasive procedures performed after study enrollment		At one month (average)	No
Secondary	Intravenous fluids infused in first 2 hours after enrollment		First 2 hours after study enrollment	No
Secondary	Intravenous fluids infused in first 48 hours after enrollment		First 48 hours after study enrollment	No
Secondary	Need for hemodialysis		At one month (average)	No