Physiological Considerations for Compression Bandaging

Physiological Considerations for Compression Bandaging

Harvey N. Mayrovitz, Ph.D.Professor of PhysiologyCollege of Medical SciencesNova Southeastern [email protected]

At the completion of this presentation participants will be able to:

1. State the difference between edema andlymphedema

2. State at least one process that can causeedema

3. Describe the basic processes involved inlymphatic transport

4. Describe long-stretch and short-stretchbandages and their use

5. Contrast the effects of resting vs. workingpressures

6. Describe Laplace’s law as it applies tobandaging

Dr. HN Mayrovitz

Relationship to Wound Healing

Impediments to HealingImpediments to Healing• Blood Flow• Oxygenation• Infection• Tissue Environment

Deficit OriginsDeficit Origins• Arterial• Venous• Microvascular• Lymphatic

Compression Therapy

LocalizedEdema/Lymphedema

Dr. HN Mayrovitz

Circulation Schema

H 2O

ArteryArtery

Vein

LymphaticsLymphatics

O2 CO2 CapillaryCapillary

ArteriolesArterioles

Dr. HN Mayrovitz

Normal Fluid Balance

35 mmHg

15

Π = 25 mmHg

FiltrationResorption

Lymphatic Capillary

~30 liters/day

PA

PV

protein

Blood Capillary

~27 liters/day

~3 liters/day(10% of filtered)

Dr. HN Mayrovitz

35 mmHg

Filtration

Lymphatic Capillary

Increased Venous Pressureor Capillary Permeability

••Less ResorptionLess Resorption

20PV

PA

•More Filtration

Resorption

Blood Capillary

Dr. HN Mayrovitz

If Net Filtration ExceedsLymphatic Transport Capacity

Overload = Edema+ [Protein]

= Lymphedema= Lymphedema

Therapy Options• Reduce Filtration• Increase Transport

Dr. HN Mayrovitz

Normal Lymph TransportNormal Lymph Transport

••Lymphangion ContractionLymphangion Contraction

••Skeletal Muscle PumpSkeletal Muscle Pump

••Arterial PulsationsArterial Pulsations

••Body MovementsBody Movements

••RespirationRespiration

All are Dynamic ProcessesDr. HN Mayrovitz

Lymphatic Capillaries

EC

Lumen PL

PT

EC

Lumen PL

+PT

PL > PT

PL < PT

AnchoringFilaments Blood Capillary

Lymphatic Capillary

Dr. HN Mayrovitz

Lymphatic ‘Hearts’

ValveLymphangion(lymph micro heart)

LymphCapillary

Walls have amuscular media

Peristaltic-like contractionspropel lymph to next segment

LymphangionLymphCapillary

Contraction force is preload andafterload dependent - analogous to heart

Dr. HN Mayrovitz

Calf Muscle Pump and Calf Muscle Pump and Normal ValvesNormal Valves

Superficial Deep

Rel

axed

FasciaSkin

Superficial Deep

Con

trac

ted

Skin FasciaDr. HN Mayrovitz

Calf Muscle Pump and Valve Dysfunction

Rel

axed

Resting Venous PressureResting Venous PressureINCREASEDINCREASED

VeinsVeinsDistendedDistended C

ontr

acte

d

•• High pressure transmittedHigh pressure transmittedto Superficial Veinsto Superficial Veins

•• Pump Efficiency ReducedPump Efficiency Reduced

Venous Valve DysfunctionChronic venous hypertension due toChronic venous insufficiency (CVI)

predisposes to developing venous ulcersIncreased Ambulatory Venous Pressure

VenousVenousPressurePressure

NormalNormal

CVIResting

Dr. HN Mayrovitz

ExternalCompression

TissueTissuePressurePressure

Vein Vein Diameter

TransTrans--locatelocateVolumeVolume

VenousVenousPressurePressure

Diameter

ArteriolarVasodilation VelocityVelocity

Shear Shear StressStress

NitricOxide Promote

FluidAbsorptionNormalize

PermeabilityWBC WBC

AdherenceAdherenceDr. HN Mayrovitz

Types of Compression

•Bandage

•Bandage-like

•Pumps

•Stockings

Short-StretchLong -Stretch

Short-Stretch

Dynamic

PreventionMaintenance

Dr. HN MayrovitzDr. HN Mayrovitz

Arrangement

Superficial

Facia

Skin

VascularSheath

MuscleDeep

Bone

DrainsSkin andSubcutis

Dr. HN Mayrovitz

Vascular Sheath

V

VA

L

L

Arterial Pulsations Can Mechanically Arterial Pulsations Can Mechanically Augment Lymph TransportAugment Lymph Transport

Dr. HN Mayrovitz

Arterial Flow Pulses Below Knee Blood Flow via Nuclear Magnetic Resonance Below Knee Blood Flow via Nuclear Magnetic Resonance

Control Leg Treated LegControl Leg Treated LegBeforeBefore

Bandage52 47

49 74

ml/min Bandage

WithWithBandageBandage

Increased pulses Increased pulses likely augment likely augment Lymph/venousLymph/venous

transporttransport

ml/min

Dr. HN Mayrovitz

Compartments

SuperficialPosterior

DeepPosterior

Anterior

Lateral

GreaterSaphenous

Lesser Saphenous

PosteriorTibial

Peroneal

AnteriorTibial

Skin

Tibia

Fibula

Want Therapy to Affect Superficial and DeepDr. HN Mayrovitz

Pressures of Interest

Skin

••SubSub--bandagebandage••SurfaceSurface••ContactContact

CompressionBandage or Device

••TissueTissue••InterstitialInterstitial

••IntramuscularIntramuscular

Tibialis m.

Soleus m.

Gastroc m.

Popliteus m.Tibialis m.

Peroneus

Tibia

Fibula

2

3

1

Dr. HN Mayrovitz

Edema and Tissue Pressure

Normal

PT

Loose Fibrous Trabeculae

PT

Dr. HN Mayrovitz

Resting (Static) Pressure

P ~ P ~ TTRR

Superficial vessels affected the mostSuperficial vessels affected the most

LaplaceLaplace’’ssLawLaw

MusclesMusclesRelaxedRelaxed

R

CompressionBandage or Device

T

Pressure dueto bandagetension (T)projecting an inward

radialpressure (P)

Dr. HN Mayrovitz

Pressure Gradient Concept

Compression Appliedat Constant Tension

P ~ P ~ TTRR

Increasing RIncreasing RDecreasing PDecreasing P

Mimics Normal Intravascular

PressureGradient

Dr. HN Mayrovitz

Working (Dynamic) PressureBandage acts as a Bandage acts as a restraint to muscle restraint to muscle

expansion expansion

P ~ Contraction Force x P ~ Contraction Force x ‘‘RigidityRigidity’’

P

ContractedContractedMusclesMuscles

Positive Positive affect on affect on

deeperdeepervesselsvessels

Pressure isPressure isdevelopeddeveloped

from from ‘‘withinwithin’’

Dr. HN Mayrovitz

Dynamic Pressure Depends onBandage Material Features

Bandage ‘Stretchibility’

No externalcompression

0

Form fitted steel pipe

‘shortstretch’

‘longstretch’

Dyn

amic

Pre

ssur

e (∆

P)

Dr. HN Mayrovitz

Working vs. Resting PressuresRole of Compression Material

ShortShortStretchStretch LongLong

StretchStretch

Filling Filling

Resting

Tiss

ue P

ress

ure

(PT)

Time

Emptying

Dr. HN Mayrovitz

Overall Impact of Compression Overall Impact of Compression Depends on both working and resting pressures

A

PT

PUUpstreamPressure

TissuePressure

Vein or Lymphatic

••FillingFilling: Inflow ~ PU - PT

••EmptyingEmptying: Outflow ~ ∆V ~ ∆PT

••BestBest: Adequate resting PT and High ∆PT

Dr. HN Mayrovitz

PneumaticSensor*

ElectronicSensor*

ElectronicPressureReadout

Sub-Bandage Pressure Measurements

Compression set at various static levels to compare dynamic sub-bandage pressuresachieved with different bandages duringcalf muscle contraction and relaxation

*Pneumatic sensor: Talley Oxford Pressure Monitor*Electronic Sensor: http://bioscience-research.net

Dr. HN Mayrovitz

Dynamic (Working) Pressures

0

150

mm

Hg

30 40 50

Static

Static Pressures Set by Compression

Dynamic pressures via calf muscle contractionDynamic pressures via calf muscle contractionDynamic

CohesiveCohesive ElasticElastic MultilayerMultilayer0

150

mm

Hg

Comparison of Different Bandage TypesInefficient Low

Dynamic Pressure Efficient

Dynamic Pressure

Dr. HN Mayrovitz

Multiple Choice Questions1. According to Laplace’s law, if a limb is bandaged with constant tension, then the

contact pressure experienced by the limb will be:a) greater where the limb is widestb) greater where the limb is narrowest*c) equal at all sites since the tension is constantd) least over areas of bony prominence such as the malleolus

2. A short-stretch bandage, as compared to a long-stretch:a) results in a greater resting pressureb) affects the deep vessels more than the superficial vesselsc) results in a greater working pressure*d) has a greater effect on underlying blood vessels at rest

3. A short-stretch bandage provides more efficient venous and lymphatic filling andemptying because it produces:

a) greater working pressure and greater resting pressureb) reduced working pressure and reduced resting pressurec) greater working pressure and reduced resting pressure*d) reduced working pressure and greater resting pressure

References1. Mayrovitz HN, Larsen PB. Effects of compression bandaging on leg pulsatile blood flow.

Clinical Physiology 1997;17:105-172. Mayrovitz HN . Compression-Induced pulsatile blood flow changes in human legs.

Clinical Physiology, 1997;18:117-24.3. Mayrovitz HN, Delgado M., Smith J. Compression bandaging effects lower extremity peripheral and

sub- bandage skin blood perfusion. Wounds 1997;9:146-52.4.4. Mayrovitz HN, Sims N (2003) Effects of ankle-to-knee external pressures on skin blood perfusion in the

compressed leg and non-compressed foot. Adv Skin Wound Care 2003;16:198-202