Jugular Venous Blood Flow Research Articles

Assessment of Jugular Venous Blood Flow Stasis and Thrombosis During Spaceflight

Exposure to a weightless environment during spaceflight results in a chronic headward blood and tissue fluid shift compared with the upright posture on Earth, with unknown consequences to cerebral venous outflow. To assess internal jugular vein (IJV) flow and morphology during spaceflight and to investigate if lower body negative pressure is associated with reversing the headward fluid shift experienced during spaceflight. This prospective cohort study included 11 International Space Station crew members participating in long-duration spaceflight missions . Internal jugular vein measurements from before launch and approximately 40 days after landing were acquired in 3 positions: seated, supine, and 15° head-down tilt. In-flight IJV measurements were acquired at approximately 50 days and 150 days into spaceflight during normal spaceflight conditions as well as during use of lower body negative pressure. Data were analyzed in June 2019. Posture changes on Earth, spaceflight, and lower body negative pressure. Ultrasonographic assessments of IJV cross-sectional area, pressure, blood flow, and thrombus formation. The 11 healthy crew members included in the study (mean [SD] age, 46.9 [6.3] years, 9 [82%] men) spent a mean (SD) of 210 (76) days in space. Mean IJV area increased from 9.8 (95% CI, -1.2 to 20.7) mm2 in the preflight seated position to 70.3 (95% CI, 59.3-81.2) mm2 during spaceflight (P < .001). Mean IJV pressure increased from the preflight seated position measurement of 5.1 (95% CI, 2.5-7.8) mm Hg to 21.1 (95% CI, 18.5-23.7) mm Hg during spaceflight (P < .001). Furthermore, stagnant or reverse flow in the IJV was observed in 6 crew members (55%) on approximate flight day 50. Notably, 1 crew member was found to have an occlusive IJV thrombus, and a potential partial IJV thrombus was identified in another crew member retrospectively. Lower body negative pressure was associated with improved blood flow in 10 of 17 sessions (59%) during spaceflight. This cohort study found stagnant and retrograde blood flow associated with spaceflight in the IJVs of astronauts and IJV thrombosis in at least 1 astronaut, a newly discovered risk associated with spaceflight. Lower body negative pressure may be a promising countermeasure to enhance venous blood flow in the upper body during spaceflight.

Kaolin-activated thromboelastography in echocardiographically normal cats

To determine reference values for kaolin-activated thromboelastography in echocardiographically normal cats. 30 healthy cats without evidence of cardiomyopathy on echocardiographic examination. All cats underwent echocardiographic examination, the findings of which were reviewed by a board-certified cardiologist. Cats that struggled (n = 10) received mild sedation with butorphanol and midazolam IM to permit phlebotomy without interruption in jugular venous blood flow. Blood samples were collected for analysis of thromboelastography variables, PCV, total solids concentration, platelet count, activated partial thromboplastin time, prothrombin time, fibrinogen concentration, and antithrombin concentration. All 4 thromboelastography variables had < 5% mean intra-assay variability. Mean values were as follows: reaction time, 4.3 minutes; clotting time, 1.6 minutes; α angle, 66.5°; and maximum amplitude, 56.4 mm. Compared with nonsedated cats, cats that required sedation had a significantly shorter clotting time and greater α angle, whereas reaction time and maximum amplitude were not significantly different. Kaolin-activated thromboelastography was a reliable test with unremarkable intra-assay variability in echocardiographically normal cats. Sedation may affect certain thromboelastography variables, but the effect is unlikely to be clinically important. It remains unknown whether subclinical cardiomyopathy has a significant effect on thromboelastography variables in cats.

Jugular venous blood flow velocity waveforms in human fetuses between 20 and 42 weeks of pregnancy.

The goal of the study was to measure the blood flow parameters of the fetal internal jugular vein during the second half of normal pregnancy using Doppler ultrasound. Jugular blood flow was analyzed in 95 normal singleton fetuses between 20 and 42 weeks gestation. Color and pulsed Doppler ultrasound was used to obtain jugular venous waveforms at the level of the mid-neck. Peak velocities, ratios of velocities, and time-averaged maximum velocities were measured. Jugular venous waveforms in healthy fetuses consist of three phases--the first forward peak occurs during ventricle systole; the second forward peak occurs during early diastole and the third peak occurs during atrial contraction. Forty-eight percent of the fetuses demonstrated absent flow during atrial contraction; 32% of fetuses demonstrated forward flow during atrial contraction and finally 20% of fetuses demonstrated flow reversal during atrial contraction. The reported jugular venous profile may serve as a foundation for future studies of jugular blood flow in high risk fetuses.

Jugular venous blood flow in fetuses with single nuchal umbilical cord

Jugular venous blood flow in fetuses with single nuchal umbilical cord

Transcranial Doppler-estimated versus thermodilution-estimated cerebral blood flow during cardiac operations: Influence of temperature and arterial carbon dioxide tension

The ability of the noninvasive continuous transcranial Doppler technique to reflect changes in cerebral blood flow during cardiac operations was evaluated in seven adults. Middle cerebral artery blood flow velocity changes were compared with simultaneous thermodilution measurements of venous blood flow in the ipsilateral internal jugular vein during 11 preset stages of the procedure. Cerebral blood flow was varied by changes in arterial carbon dioxide tension and temperature. High-dose fentanyl-droperidol anesthesia and alpha-stat pH management were employed. To facilitate comparisons between the two methods, the individual awake values of middle cerebral artery flow velocity (45.1 +/- 3.3 cm/sec, mean +/- standard error of the mean) and jugular venous blood flow (382 +/- 37 ml/min) were normalized (100%). Cerebral metabolic rate for oxygen was calculated as the product of jugular arteriovenous oxygen content difference and middle cerebral artery flow velocity or jugular venous blood flow, respectively. The individual correlations between the two flow estimates varied between 0.76 and 0.87 (median 0.83), and the correlation of the combined data from all seven patients was 0.77 (p less than 0.0001). Variations in arterial carbon dioxide tension induced significant changes in the two flow estimates both during normothermia before cardiopulmonary bypass and at deep hypothermia (20 degrees C) during cardiopulmonary bypass. The significant arterial carbon dioxide tension changes had no significant effects either on Doppler- or thermodilution-estimated cerebral metabolic rate for oxygen. Deep hypothermia (20 degrees C) reduced Doppler- and thermodilution-estimated cerebral metabolic rate for oxygen to 22.0% +/- 3.9% and 20.6% +/- 6.9% of the awake levels, respectively. The study supports the validity of using middle cerebral arterial flow velocity changes as an estimate of changes in volume flow through the brain during cardiac operations.

Influence of abdominal surgical trauma on substrate utilization by the human brain.

In 10 patients undergoing cholecystectomy, measurements of jugular venous blood flow (one side) and arterio‐jugular vein differences of oxygen, glucose, lactate, pyruvate, glycerol, 3‐hydroxybutyrate and alanine were made. The arterial concentration of 3‐hydroxybutyrate was raised during surgery, but this substrate only covered a minute part of the total energy demand. The need for substrates of oxidative metabolism in the brain was met by glucose. During the operation the stoichiometrically calculated oxygen uptake was lower than that of glucose, indicating an increase in the brain glucose content.

Effect of feeding on jugular venous blood flow in the normal newborn infant.

Jugular venous occlusion plethysmography was used to measure jugular blood flow in 47 infants; this was done at varying times after the end of a feed. Jugular blood flow was found to be lower, by about 30%, during the first postprandial half hour than at any other time up to 2 hours postprandially. In 2 infants longitudinal studies were performed in relation to several feeds, and postprandial reductions in blood flow of a similar magnitude were found. Aspects of the venous occlusion technique are discussed. It is concluded that feeding in healthy neonates is associated with a subsequent reduction in jugular blood flow, and possible mechanisms for this phenomenon are discussed.

Atrial versus ventricular contribution in determining systolic venous return. A new approach to an old riddle.

In order to compare the contribution of atrial relaxation and ventricular contraction in determining systolic atrial filling, the jugular venous blood flow velocity curve was recorded transcutaneously with a directional Doppler flowmeter in 81 cases of arrhythmias involving dissociation between atrial and ventricular activity (A-V block, atrial fibrillation, atrial standstill, nodal rhythm, wandering pacemaker). After a brief historical review of the subject the recorded tracings are analysed and evidence provided for the participation of both cardiac events in achieving normal systolic return.

Bilateral jugular venous blood flow by thermal dilution.

Measurements of internal jugular venous flow were made in 12 patients with severe cerebral vascular disease. Flow rates were determined by the thermal dilution method, using room temperature physiological (heparinized) saline as an indicator infused at a constant rate. The major sources of error (indicator mixing) were studied under highly controlled in vitro experiments. Total jugular venous outflow was substantially below mean values of total cerebral flow for normal subjects and somewhat below the mean values for demented patients. Free communication between the two jugular veins via the torcular was observed in all patients. Following unilateral venous compression, the differential shift to the contralateral vein was not always equal to the precompression total flow. This would seem to indicate that this maneuver produces some diversion of flow to other venous channels and suggests that total cerebral blood flow can be obtained reliably only through bilateral measurements.

A catheter probe for measurement of jugular venous blood flow in man by thermal dilution.

ArticleA catheter probe for measurement of jugular venous blood flow in man by thermal dilution.R D Lowe, and D J DowsettR D Lowe, and D J DowsettPublished Online:01 Dec 1967https://doi.org/10.1152/jappl.1967.23.6.1001MoreSectionsPDF (784 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByMeasurement of flow in large veins by the continuous thermodilution methodResearch in Experimental Medicine, Vol. 186, No. 2Measurement of blood flow by thermodilutionThe American Journal of Cardiology, Vol. 29, No. 2The Measurement of Local Cerebral Blood Flow and the Effect of Amines More from this issue > Volume 23Issue 6December 1967Pages 1001-3 https://doi.org/10.1152/jappl.1967.23.6.1001PubMed4863735History Published online 1 December 1967 Published in print 1 December 1967 Metrics