LOINCActiveObservation

LOINC Code 20355-4: Peak blood flow 2 by US.doppler

20355-4 is a LOINC code used to identify Peak blood flow 2 by US.doppler in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Blood flow 2.max. It is commonly used with the system or sample type Circulatory system.XXX.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Blood flow 2.max. It is commonly used with the system or sample type Circulatory system.XXX.

When is it used?

  • Used in lab systems, EHRs, and clinical data exchange.
  • May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
  • Status: ACTIVE
  • Order vs observation: Observation
  • Method: US.doppler

What it does not mean

  • The code identifies the observation or test, not the actual result.

Key facts

  • Peak blood flow 2 by US.doppler
  • Blood flow 2.max
  • Bld flow; Bld flow 2; Bld flow 2.max; CARD.US; Cardio; Cardiology; Circ; Circ sys; DOP; DUPLEX; Dynamic; Echography; Heart Disease; II; Largest; Max V; Maximal; Maximum; Misc; Miscellaneous; Other; Peak; Point in time; QNT; Quan; Quant; Quantitative; Random; Sonogram; Sonograph; Sonography; Spec; To be specified in another part of the message; ULS; Ultrasound; Unspecified; V max; VEL max; Velocity; Vmax

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Peak blood flow 2 by US.dopplerBld flow 2.max DOPBlood flow 2.maxCARD.USVelPtCirculatory system.XXX

Frequently asked questions

Code details

Code20355-4
SystemLOINC
Display namePeak blood flow 2 by US.doppler
DescriptionBlood flow 2.max
Short nameBld flow 2.max DOP
ComponentBlood flow 2.max
PropertyVel
TimingPt
System (specimen)Circulatory system.XXX
ScaleQn
MethodUS.doppler
ClassCARD.US
Example unitsm/s; cm/s
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0m
Last changed2.48

Part names

Blood flow 2.maxVelPtCirculatory system.XXXQnUS.dopplerVelocity (distance/time)Point in time (spot)Circulatory system XXXUltrasound.doppler

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

LOINC Code 20355-4 | HealthAssure