The goal of this clinical trial is to determine if perfusion index (PI) can reliably predict changes in systolic blood pressure (SBP) in persons with spinal cord injury (SCI) during a cool temperature challenge. Participants with SCI can be 18-75 years of age, male or female, neurological level of injury C4-T12, ASIA Impairment Scale (AIS: A or B: motor complete) or gender and healthy age-matched able-bodied (AB) controls.
The main question this study aims to answer is: can PI reliably predict change in SBP during a cool temperature challenge? The investigators hypothesize that PI can be used as a biomarker of SBP in persons with SCI.
Researchers will compare the relationship of 1) changes in PI and SBP and 2) relationship of changes in other vital signs to SBP, during the cool temperature challenge. The researchers aim to determine if PI can be used as a biomarker of SBP in persons with SCI during a cool temperature challenge (experimental group/arm). Able-bodied controls (control group/arm) will receive the same intervention (cool challenge) as the experimental group.
During the study, participants will be asked to wear only shorts and a T-shirt so that their skin can be exposed to the warm and cool temperatures of the 2 rooms.
The investigators will put put on non-invasive sensors (taped or attached on the surface of your body) to measure PI, BP, and other vital signs. The investigators will record these measurements while the participant is seated in a wheelchair for 10 minutes in a warm room and up to 90 minutes in a cool room.
The participant had a spinal cord injury (SCI: C4-T12) for more than one year and the SCI was graded as ASIA Impairment Scale (AIS) A or B (unable to voluntarily move your legs)
The participant can also be a gender and age-matched (±5 years) able-bodied (AB) control subject (similar gender and age to a subject with SCI).
Subjects with SCI and AB controls must be between 18 and 75 years of age.
If the participant are going to do the study, they must avoid caffeine and alcohol, maintain normal salt and water intake, and avoid strenuous exercise for 24 hours prior to the study visit.
The participant has cardiovascular, kidney, or untreated thyroid disease
The participant has had a traumatic brain injury (TBI)
The participant has diabetes mellitus
The participant has an acute illness or infection
Parallel
Controlled Cool Thermal Challenge (18°C)
Other interventionParticipants with SCI will undergo a controlled, non-invasive cool thermal challenge of 18°C (64.4°F) in a climate-controlled chamber for up to 90 minutes. Participants will remain seated in their wheelchair while wearing a standard T-shirt and shorts to ensure uniform skin exposure. Continuous non-invasive monitoring of perfusion index and blood pressure will be performed throughout the baseline of 27°C (80°F) and cool challenge 18°C (64.4°F) phases to evaluate their relationship.
Controlled Cool Thermal Challenge (18°C)
Other interventionAble-bodied participants will undergo a controlled, non-invasive cool thermal challenge of 18°C (64.4°F) in a climate-controlled chamber for up to 90 minutes. Participants will remain seated in a wheelchair that will be provided while wearing a standard T-shirt and shorts to ensure uniform skin exposure. Continuous non-invasive monitoring of perfusion index and blood pressure will be performed throughout the baseline of 27°C (80°F) and cool challenge 18°C (64.4°F) phases to evaluate their relationship.
Perfusion Index (PI)
Perfusion index (PI: ranging from 0.02 to 20) reflects the ratio of pulsatile (arterial) blood flow to non-pulsatile static blood flow. PI will be continuously collected using Masimo Radical-7 pulse oximeters (Masimo Corp., Irvine, CA) attached to three sites: an ear, a finger, and a toe. This multi-site data will serve as the primary independent predictor variable of SBP in the AI/machine learning models.
Systolic Blood Pressure (SBP)
Beat-to-beat systolic blood pressure (SBP: mmHg) will be continuously collected via a finger-cuff sensor using the VitalStream-CM wireless hemodynamic monitor (CareTaker Medical LLC, Charlottesville, VA). SBP will serve as the primary target dependent variable that the investigators are trying to predict to evaluate sympathetic/vascular reactivity and to train the non-invasive machine learning prediction algorithms.
Click on the lead sponsor to view all of their trials.
