Table 6 Appropriateness criteria and comparison of inflight venous ultrasound with terrestrial standards.

From: Systematic review of the use of ultrasound for venous assessment and venous thrombosis screening in spaceflight

Appropriateness criteria

DVT studies (N = 3)

Other studies (N = 15)

Appropriate crew for venous ultrasound assessment (experience)

Experts: 0

Experts: 4

- Expert physician or sonographer on board OR

Remote control: 0

Remote control: 0

- Ground-based manual remote control

NR: 0

NR: 4

Appropriate in-flight equipment

  

- Peripheral veins: High-frequency emission probe in B-mode US (e.g., L12-5 MHz) – Colour-Doppler US – Duplex US

Yes: 3 (No: 0, NR: 0)

Yes: 7 (No: 2, NR: 6)

- Central veins: Low- frequency emission probe in B-mode US (e.g., C5-2 or P5-2 MHz) - Colour-Doppler US - Duplex US (with a small size probe for intrathoracic venous assessment)

Yes: 0 (No: 3, NR: 0)

Yes: 4 (NA: 10, NR: 1)

Appropriate assessment sites (both to be combined for venous thrombosis detection)

Yes: 0

Adapted to the study

- Peripheral veins: Whole venous network AND

- Only IJV assessed

 

- Central veins: Direct assessment (subclavian vein and innominate trunk) + Indirect assessment from peripheral veins

- No direct assessment of central veins

 

Appropriate assessment methods (both to be combined for venous thrombosis detection)

Yes: 3 (Both assessment methods combined)

Adapted to the study

- Morphological assessment: echogenicity, flow direction, thrombosis image, compression US test (for peripheral veins) AND

  

- Hemodynamic assessment (Colour-Doppler US + Duplex US): filling of the vein segment, blood flow velocity (doppler pattern, magnitude, direction)

  

Appropriate criteria to rule-out venous thrombosis:

  

- Peripheral veins: vein compressibility (B-mode) + absence of thrombus direct image (B-mode) + normal filling of the vein segment (Colour-Doppler)

Yes: 3

NA

- Central veins: absence of direct thrombus image and absence of vein obstruction (B-mode and Colour-Doppler) + normal phasicity with respiration and cardiac cycle at the level of the axillary vein (in supine position on-Earth) for the assessment of intrathoracic veins (using duplex ultrasound)*

Not assessed.

 

Appropriate criteria to rule-in venous thrombosis:

  

- Peripheral veins: non-full compressibility of the vein segment (B-mode) + partial or complete venous obstruction (B-mode and Colour-Doppler) + high quality thrombosis direct image (B-mode)

Main issue: Quality of thrombosis image.

NA

- Central veins: partial or complete venous obstruction (B-mode and Colour-Doppler) + high quality thrombosis direct image (B-mode) + loss of phasicity with respiration and cardiac cycle at the level of the axillary veins in supine position for the assessment of intrathoracic veins (using duplex ultrasound)

Not assessed.

 
  1. Among the 16 included publications: one reported exclusively on DVT study, two on both DVT studies and other types of studies, and 13 exclusively on other types of studies. Other studies = Not DVT studies. Neck and upper extremity peripheral venous segments: internal jugular veins (IJV), brachial and axillary veins – Neck and upper extremity central venous segments: deep IJV segment, subclavian, brachiocephalic venous trunk, superior vena cava. Remote Control is Remote Manual Control.
  2. Yes appropriate, No not appropriate, NA not applicable, NR not reported.
  3. *+ reversal of stasis phenomenon in-flight under venous interventions (i.e., mainly modified Mueller manoeuvre and the contralateral manual compression of the right IJV).
Back to article page