Carotid flow time changes with volume status in acute blood loss.
Document Type
Article
Publication Date
9-1-2015
Institution/Department
Emergency
Journal Title
Annals of emergency medicine.
MeSH Headings
Adult, Blood Flow Velocity, Blood Volume, Carotid Arteries, Female, Hemorrhage, Humans, Male, Prospective Studies, Supine Position, Ultrasonography
Abstract
STUDY OBJECTIVE: Noninvasive predictors of volume responsiveness may improve patient care in the emergency department. Doppler measurements of arterial blood flow have been proposed as a predictor of volume responsiveness. We seek to determine the effect of acute blood loss and a passive leg raise maneuver on corrected carotid artery flow time.
METHODS: In a prospective cohort of blood donors, we obtained a Doppler tracing of blood flow through the carotid artery before and after blood loss. Measurements of carotid flow time, cardiac cycle time, and peak blood velocity were obtained in supine position and after a passive leg raise. Measurements of flow time were corrected for pulse rate.
RESULTS: Seventy-nine donors were screened for participation; 70 completed the study. Donors had a mean blood loss of 452 mL. Mean corrected carotid artery flow time before blood loss was 320 ms (95% confidence interval [CI] 315 to 325 ms); this decreased after blood loss to 299 ms (95% CI 294 to 304 ms). A passive leg raise had little effect on mean corrected carotid artery flow time before blood loss (mean increase 4 ms; 95% CI -1 to 9 ms), but increased mean corrected carotid artery flow time after blood loss (mean increase 23 ms; 95% CI 18 to 28 ms) to predonation levels.
CONCLUSION: Corrected carotid artery flow time decreased after acute blood loss. In the setting of acute hypovolemia, a passive leg raise restored corrected carotid artery flow time to predonation levels. Further investigation of corrected carotid artery flow time as a predictor of volume responsiveness is warranted.
ISSN
1097-6760
First Page
277
Last Page
282
Recommended Citation
Mackenzie, David C; Khan, Noman A; Blehar, David; Glazier, Scott; Chang, Yuchiao; Stowell, Christopher P; Noble, Vicki E; and Liteplo, Andrew S, "Carotid flow time changes with volume status in acute blood loss." (2015). Maine Medical Center. 836.
https://knowledgeconnection.mainehealth.org/mmc/836
