Study: NCT01128413

Intervention type: DEVICE
Group type: EXPERIMENTAL
Intervention: Cheetah NICOM® PLRT
Description: Cheetah NICOM® (non-invasive cardiac output monitoring)PLRT (passive leg raise testing) protocol: The patient while in a semi-recumbent position (legs level, torso up 45 degrees) will have 3 minutes of stroke volume and cardiac index monitoring. Following the 3 minutes, the patient will be placed in a leg raised position (torso level, legs up 45 degrees) for 3 minutes of stroke volume and cardiac index monitoring. NICOM® PLRT will be performed within 10 minutes after any fluid bolus in both arms with results blinded to the Routine Care arm. If saline locked or maintenance IV fluid rate, NICOM® PLRT will be performed every 30 minutes in both arms with results blinded to the Routine Care arm.

Intervention type: DEVICE
Group type: ACTIVE_COMPARATOR
Intervention: Cheetah NICOM® PLRT
Description: Cheetah NICOM® (non-invasive cardiac output monitoring)PLRT (passive leg raise testing) protocol: The patient while in a semi-recumbent position (legs level, torso up 45 degrees) will have 3 minutes of stroke volume and cardiac index monitoring. Following the 3 minutes, the patient will be placed in a leg raised position (torso level, legs up 45 degrees) for 3 minutes of stroke volume and cardiac index monitoring. NICOM® PLRT will be performed within 10 minutes after any fluid bolus in both arms with results blinded to the Routine Care arm. If saline locked or maintenance IV fluid rate, NICOM® PLRT will be performed every 30 minutes in both arms with results blinded to the Routine Care arm.

Intervention type: DEVICE
Group type: EXPERIMENTAL
Intervention: USCOM ® (Ultrasound Cardiac Output Monitor)
Description: Patients while in the Cheetah NICOM® PLRT semi-recumbent position (legs level, torso up 45 degrees) will have simultaneous USCOM® stroke volume and cardiac index monitoring. Following the 3 minutes of Cheetah NICOM® PLRT semi-recumbent positioning, the patient will be placed in a leg raised position (torso level, legs up 45 degrees) and have simultaneous USCOM® stroke volume and cardiac index monitoring. USCOM® monitoring will be blinded to the Routine Care arm unless used as part of a provider's routine practice. USCOM® changes in SVI or CI with PLRT will be calculated after the patient leaves the ED.

Intervention type: DEVICE
Group type: ACTIVE_COMPARATOR
Intervention: USCOM ® (Ultrasound Cardiac Output Monitor)
Description: Patients while in the Cheetah NICOM® PLRT semi-recumbent position (legs level, torso up 45 degrees) will have simultaneous USCOM® stroke volume and cardiac index monitoring. Following the 3 minutes of Cheetah NICOM® PLRT semi-recumbent positioning, the patient will be placed in a leg raised position (torso level, legs up 45 degrees) and have simultaneous USCOM® stroke volume and cardiac index monitoring. USCOM® monitoring will be blinded to the Routine Care arm unless used as part of a provider's routine practice. USCOM® changes in SVI or CI with PLRT will be calculated after the patient leaves the ED.

Intervention type: DEVICE
Group type: EXPERIMENTAL
Intervention: Inferior Vena Cava (IVC) Ultrasound Collapsibility
Description: Patients while in the Cheetah NICOM® PLRT semi-recumbent position (legs level, torso up 45 degrees) will have a simultaneous 6-12 second ultrasound recording of their IVC. These recordings will be reviewed later by an ultrasonographer and graded for volume responsiveness. The reviewing ultrasonographer will be blinded to the Cheetah NICOM® PLRT results.

Intervention type: DEVICE
Group type: ACTIVE_COMPARATOR
Intervention: Inferior Vena Cava (IVC) Ultrasound Collapsibility
Description: Patients while in the Cheetah NICOM® PLRT semi-recumbent position (legs level, torso up 45 degrees) will have a simultaneous 6-12 second ultrasound recording of their IVC. These recordings will be reviewed later by an ultrasonographer and graded for volume responsiveness. The reviewing ultrasonographer will be blinded to the Cheetah NICOM® PLRT results.

Intervention type: BEHAVIORAL
Group type: EXPERIMENTAL
Intervention: CURVES Questionnaire
Description: The CURVES (CardiovascUlar Response \& Volume Estimation in Shock) Questionnaire consists of multiple provider questions aimed at defining the presumed shock etiology and anticipated responses to interventions. This will be administered to both arms.

Intervention type: BEHAVIORAL
Group type: ACTIVE_COMPARATOR
Intervention: CURVES Questionnaire
Description: The CURVES (CardiovascUlar Response \& Volume Estimation in Shock) Questionnaire consists of multiple provider questions aimed at defining the presumed shock etiology and anticipated responses to interventions. This will be administered to both arms.

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: Lactate Clearance
Description: Lactate samples will be drawn at time 0, 1, 3, \& 6 hours (or at ED departure if before 6 hours). Time 0 lactate will be revealed to the Routine Care arm and subsequent lactates revealed to the Routine Care arm only if serial lactates are part of the provider's routine practice.

Intervention type: BIOLOGICAL
Group type: ACTIVE_COMPARATOR
Intervention: Lactate Clearance
Description: Lactate samples will be drawn at time 0, 1, 3, \& 6 hours (or at ED departure if before 6 hours). Time 0 lactate will be revealed to the Routine Care arm and subsequent lactates revealed to the Routine Care arm only if serial lactates are part of the provider's routine practice.

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: 500ml Normal Saline Bolus
Description: Patients randomized to the experimental arm and having a \>/= 15% change in stroke volume index (SVI) or cardiac index (CI) via Cheetah NICOM®PLRT will be given a 500ml normal saline fluid bolus.

Intervention type: BIOLOGICAL
Group type: ACTIVE_COMPARATOR
Intervention: Clinician Discretion Intravenous Fluid Management
Description: Clinicians caring for patients randomized to the Routine Care arm will within 10 minutes after any fluid bolus be asked to decide via their clinical discretion if they want to re-bolus, saline lock, or place the patient on a maintenance IV fluid rate. If the patient is on a saline lock or maintenance fluid rate, clinicians will be asked every 30 minutes to decide via their clinical discretion to re-bolus, saline lock, or place the patient on a maintenance IV fluid rate.