Bedside Ultrasound Evaluation and Indicators of Progression in Crotalid Snakebites
Study ID: STU-2019-0640
This protocol is a pilot study on the use of PoCuS for crotalid snakebites for the evaluation of extremity swelling and progression. our first aim seeks to compare two quantitative methods of assessment of local tissue swelling after crotalid envenomation between clinical and PoCuS evaluation: (1) Measured depth at the site of maximal swelling within 2 cm of the envenomation site of the affected limb and the same site on the other limb using PoCuS will be compared with circumferential measurements. The ratio between the affected limb and unaffected limb will be used to calculate the expansion coefficient. (2) Measured distance from the site of envenomation to the proximal leading-edge progression will be determined by the patient's own assessment, by visual/tactile exam, and by PoCuS. This will be used to calculate the percent expansion, defined as the change in leading edge in one hour over the length of the extremity. our second aim is to establish the interrater reliability for the measurement of soft tissue swelling of a crotalid envenomated limb by clinical visual/tactile evaluation and by PoCuS evaluation. The evaluation will be performed in a similar manner as aim 1 with repeat measurements an hour later.
- Cancer Related
- Healthy Volunteers
- UT Southwestern Principal Investigator
- KIM ALDY
UNIVERSITY OF TEXAS SOUTHWESTERN
overall objectives: To explore whether PoCuS will augment the evaluation of an envenomated extremity and provide more sensitive progression factors to evaluate the need for treatment. Specific aims: Specific aim 1 (Sa1): Compare the measurement of local tissue swelling from crotalid envenomation using clinical evaluation and PoCuS evaluation. * 1a: Compare the PoCuS expansion coefficient of a crotalid envenomated limb to circumferential limb measurement. * 1b: Compare the progression of proximal leading-edge by percent expansion of swelling through visual/tactile measurements to that of PoCuS measurement. * 1c: Compare progression of proximal leading-edge by percent expansion of swelling using patients own determination versus both visual/tactile measurement and PoCuS measurement. Specific aim 2 (Sa2): establish the interrater reliability for the measurement of soft tissue swelling of a crotalid envenomated limb by clinical visual/tactile evaluation and by PoCuS evaluation. * 2a: interrater reliability of limb circumference measurements as expansion coefficient. * 2b: interrater reliability of measuring PoCuS as expansion coefficient. * 2c: interrater reliability of visual/tactile proximal leading-edge by percent expansion. * 2d: interrater reliability of PoCuS proximal leading-edge by percent expansion. Hypotheses: Hypothesis 1: PoCuS measurements of soft tissue swelling from crotalid envenomation will yield greater changes than found by clinical methods (ratio of change in ultrasound measurement to change in clinical measurement [Greater Than] 1). When compared to patient's self-assessment, PoCuS findings will more closely match the patient's determination of progression as opposed to clinical evaluation. Hypothesis 2: The interrater reliability measurements of soft tissue swelling for crotalid envenomation for PoCuS and clinical measurements will have at least moderate agreement (iCC [Greater Than] 0.6). Rationale: This study may provide a more objective evaluation of progression after envenomation and lead to earlier noted tissue destruction that can be halted to prevent further patient disability. in addition, PoCuS could allow for sooner determination of non-progression which may be associated with decreased hospital stays and/or lower costs of hospital care incurred by treatment or transfer.