Transcutaneous Oxygen Testing of the Hyperbaric Problem Wound - - PowerPoint PPT Presentation

▶
transcutaneous oxygen testing
SMART_READER_LITE
LIVE PREVIEW

Transcutaneous Oxygen Testing of the Hyperbaric Problem Wound - - PowerPoint PPT Presentation

Jun 07, 2023 225 likes •679 views

RADIOMETER WEBINAR SERIES Transcutaneous Oxygen Testing of the Hyperbaric Problem Wound Referral Radiometer Webinar Series February 4, 2015 Disclosure I have occasionally served as a consultant for Radiometer, Inc., and have occasionally

slide-1
SLIDE 1

Transcutaneous Oxygen Testing

  • f the

Hyperbaric Problem Wound Referral

Radiometer Webinar Series February 4, 2015

RADIOMETER WEBINAR SERIES

slide-2
SLIDE 2

Disclosure

I have occasionally served as a consultant for Radiometer, Inc., and have occasionally received compensation for speaking at conferences sponsored by Radiometer, Inc.

slide-3
SLIDE 3

RADIOMETER WEBINAR SERIES

Genesis & clinical evolution of transcutaneous oximetry Algorithmic implementation for hyperbaric referrals Normal, adequate, abnormal LE values Provocative maneuvers Site selection principals Interpretational fundamentals

Lecture Outline

slide-4
SLIDE 4

RADIOMETER WEBINAR SERIES

Transcutaneous oximetry Transcutaneous oxygen (tension) testing TcPO2 vs. tcpO2 PtcO2 vs. ptcO2 TCOMS

Naming Conventions

slide-5
SLIDE 5

RADIOMETER WEBINAR SERIES

Transcutaneous Oximetry

Non-invasive physiologic assessment of skin microcirculatory

  • xygen delivery

~ in contrast to standard hemodynamic & anatomic testing

slide-6
SLIDE 6

RADIOMETER WEBINAR SERIES

Historical perspectives

Neonatology Plastic Surgery Orthopedic Surgery Vascular Surgery

slide-7
SLIDE 7

RADIOMETER WEBINAR SERIES

Clark LC, et al. 1953 J Applied Physiology;6:189-193 Evans NTS, Naylor PFD: 1967 Respiration Physiology ;3:21-37

slide-8
SLIDE 8

RADIOMETER WEBINAR SERIES

Huch R, et al. 1972 Pflugers Archiv;337(3):185-198

slide-9
SLIDE 9

RADIOMETER WEBINAR SERIES

Achauer BM, et al. 1980 Plastic & Reconstructive Surg;65(6):738-745

slide-10
SLIDE 10

RADIOMETER WEBINAR SERIES

Burgess EM, Matsen FA 1981 Journal Bone & Joint Surg:1493-1467 Harward TRS, et al. 1985 Journal Vascular Surg;2:220-227

slide-11
SLIDE 11

RADIOMETER WEBINAR SERIES

Matsen FA, et al. 1980 Surgery, Gynecology & Obstetrics;150:525-528

slide-12
SLIDE 12

RADIOMETER WEBINAR SERIES

Hauser CJ, et al. 1984 Archives Surgery; 119:690-694

slide-13
SLIDE 13

RADIOMETER WEBINAR SERIES

Superiority of tcpO2 Assessment

~ non-invasive lower extremity studies

Superiority of tcpO2 to Doppler studies highly significant Regional tcpO2 had higher diagnostic accuracy than ABI; PVR & TPRT in diabetic vascular disease tcpO2 provides most objective description of dermal metabolism & oxygen availability tcpO2 high degree of accuracy (vs. ABI; xenon-133; Doppler pressures) in predicting amputation site healing

Hauser CJ, 1984 Hauser CJ, 1984 Rhodes G, 1985 Malone JM, 1987

slide-14
SLIDE 14

RADIOMETER WEBINAR SERIES

Low tcpO2 Predicts Abnormal Arteriography

96% of 66 limbs with tcpO2 < 30mmHg had abnormal arteriogram

Ballard JL, et al. 1995

tcpO2 <30mmHg a reliable indicator of need for arteriography, with 98% limbs showing significant disease

Bunt TJ, et al. 1996

slide-15
SLIDE 15

RADIOMETER WEBINAR SERIES

Risk Factors For Diabetic Amputation Pathophysiologic Factor

Cutaneous circulation

~ tcpO2 <20 vs. >40mmHg

Peripheral arterial circulation

~ Doppler ABI <0.45 vs. 0.70

Neuropathy

~ lacking distal vibratory sense

Ulcers become infected

Odds Ratio 161 55.8 15.1 10.1

Reiber GE, et al. 1992

  • Ann. Int. Med;117:97-105
slide-16
SLIDE 16

RADIOMETER WEBINAR SERIES

The tcpO2 Hyperbaric Algorithm

Is wound healing complicated by hypoxia? Is any such hypoxia reversible? Is patient responding to HBO therapy? Has a therapeutic endpoint been reached? Not undertaking such determinations? …Margolis et al. Diabetes Care 2013

slide-17
SLIDE 17

RADIOMETER WEBINAR SERIES

What is a Normal Lower Extremity tcpO2 Value? Dermal oxygenation mapped in healthy volunteers

Eickhoff JH & Engell HC 1981 Wyss CR, et al. 1981 Franzeck UK, et al. 1982 Sheffield, PJ & Workman WT, 1985 Jonsson K, et al. 1987 Orenstein A, et al. 1988 Dowd GS, et al. 1993(a) Dowd GS, et al. 1993(b)

a ‘normal’ tcpO2 falls within a range of values (53-92 mmHg) reasonable to conclude that normal values exceed 50 mmHg

slide-18
SLIDE 18

RADIOMETER WEBINAR SERIES

What tcpO2 Values Considered Suboptimal?

Values > 40 mmHg representative of adequately oxygenated tissue Basic/clinical data suggests threshold range of < 35-40 mmHg as sub-optimal for O2 dependent wound healing One definition of ‘critical limb ischemia’ < 30mmHg ~ degree of adverse influence increases as values decrease ~ normal oxidative function

slide-19
SLIDE 19

Probability of Healing 100 90 80 70 60 50 40 30 20 10

0 10 20 30 40 50 60

tcpO2 (mmHg)

Padberg FT, et al. 1996 Surgical Research; 60(2)

slide-20
SLIDE 20

RADIOMETER WEBINAR SERIES

What About Any Control Sites?

Left second intercostal space grossly reflects state of ‘central’

  • xygenation….normal range 65-90mmHg (1.0 ATA)

Contra-lateral reference sites may represent poor comparison of normal to diseased tissue regional perfusion index (RPI)

slide-21
SLIDE 21

RADIOMETER WEBINAR SERIES

Evolution of Provocative Maneuvers

Treadmill exercise-induced change in Regional Perfusion Index Temporary limb ischemia-induced change in tcpO2 recovery ‘TORT’ Limb elevation-induced change in RPI…not limb elevation, per se Each directed at assessment of PVD; surgical planning None related to the issue of wound healing

slide-22
SLIDE 22

RADIOMETER WEBINAR SERIES

tcpO2 Provocative Manoeuver: HBO Referrals

Oxygen inhalation only provocative option that answers the key question: Does physiologic capacity exist to respond locally to centrally delivered oxygenation? Employable across continuum of tcpO2 algorithm Confirms adequacy of hyperbaric treatment pressure

slide-23
SLIDE 23

RADIOMETER WEBINAR SERIES

Normobaric 100% Oxygen Challenge

Response ranges

> 300 mmHg…regional large vessel disease unlikely 200-300 mmHg…minimal regional large vessel disease 100-199 mmHg…non-limb threatening ischemia 51-99 mmHg…significant ischemia: further arterial study < 50 mmHg…high grade ischemia: further arterial study

slide-24
SLIDE 24

RADIOMETER WEBINAR SERIES

Systemic Factors Influencing tcpO2

Pulmonary & cardiac function Oxygen content Central vascular perfusion Peripheral vascular perfusion Smoking, caffeine ingestion Vaso-active pharmacologic/other such substances Environment (temperature /altitude)

slide-25
SLIDE 25
slide-26
SLIDE 26

RADIOMETER WEBINAR SERIES

Local Factors Influencing tcpO2

Obesity Edema Increased skin thickness Cutaneous radiation tissue injury Bony prominences Poor skin preparation Poor electrode attachment

slide-27
SLIDE 27

RADIOMETER WEBINAR SERIES

slide-28
SLIDE 28

RADIOMETER WEBINAR SERIES

slide-29
SLIDE 29

RADIOMETER WEBINAR SERIES

Site Selection; Anatomic Factors Sensor site selection straightforward enough if… Clear understanding of question in need of address Appreciate principal determinant that answers question Principal testing site(s) consistent with that determinant Any necessary secondary testing site(s) incorporated

slide-30
SLIDE 30
slide-31
SLIDE 31
slide-32
SLIDE 32
slide-33
SLIDE 33
slide-34
SLIDE 34
slide-35
SLIDE 35
slide-36
SLIDE 36

RADIOMETER WEBINAR SERIES

Transcutaneous Oximetry: When To Delay Testing

Immediately post hemo-dialysis Nutritive skin perfusion impaired during dialysis, sufficient in some cases to produce chest/cardiac & leg pain ~ significant tcpO2 decreases in pts. with & without PVD

Weiss T, et al. 1998 Neph Dial Trans; 13

Markedly edematous tissue Edema represents a diffusion barrier between functioning capillaries & skin

Dooley J, et al. 1996 UHM;23(3): 167-174

slide-37
SLIDE 37

RADIOMETER WEBINAR SERIES

Transcutaneous Oximetry: When To Delay Testing

Caffeine ingestion Restrict caffeine-containing substances prior to tissue oximetry

~ significant differences (S.D. 270 mmHg) in healthy subjects, sufficient to screen out otherwise suitable candidates

Stephens M, et al. 1999 UHM;26(2): 93-97

Supplemental oxygen administration Absence of conversion factors Nicotine Avoid any use for at least two hours prior to tissue oximetry

Jensen JA, et al. 1994 Arch Surg; 126:1131-1134

slide-38
SLIDE 38

RADIOMETER WEBINAR SERIES

Peri-operative tcpO2 Values

~ following limb revascularization Measurement Mean(mmHg) S.D.

Preoperative 9.27** 12.14 POD #1 17.73* 15.86 POD #2 20.36* 5.61 POD #3 36.82** 18.80

* Not significant * * Significant p = 0.001

Arroyo CI, et al. 2002

  • J. Foot Ankle Surg.41(4)
slide-39
SLIDE 39

RADIOMETER WEBINAR SERIES

Possible Etiologies

Post-operative edema Vasospasm, due to high pressures Ischemia-reperfusion injury Endothelial cell trauma Micro embolic events Effects of dye

slide-40
SLIDE 40

RADIOMETER WEBINAR SERIES

Transcutaneous Oximetry

This evidence-based approach to hyperbaric wound healing confers:

More exacting patient selection Algorithmic case management Improved clinical outcomes Enhanced cost-effectiveness

slide-41
SLIDE 41
slide-42
SLIDE 42
slide-43
SLIDE 43

Normobaric Transcutaneous Algorithm

Algorithm 1

Wound hypoxia (<40mmHg): at one or more sites Yes No Normobaric (100%) oxygen challenge periwound values Baseline transcutaneous oximetry Exceed 100mmHg Range from 50-100mmHg Adequate reversal HBO not presently indicated Consider quality of life, clinical and economic issues Hyperbaric candidate To Algorithm 2 In-chamber Ptc02 if favoring HBO therapy Trial of HBO if value(s) exceed 200mmHg Further arterial testing Reconstructible disease Yes No Work up for other etiologies Refer to Wound Center To Algorithm 2 Repeat Ptc02 post procedure Wound hypoxia No Yes HBO not presently indicated Fail to reach 50mmHg Not a hyperbaric candidate under the present flow circumstances Further arterial testing HBO presently difficult to justify Yes No Reconstructible disease

slide-44
SLIDE 44

In-Chamber & Follow -Up Transcutaneous Algorithm

Algorithm 2

Obtain tcPO2 value within 15 minutes at 2.0 ATA No Yes Commence HBO at 2.0 ATA: Hypoxic wounds Titrate to 2.1 ATA Further arterial diagnostic testing Continue to titrate upwards in 0.1 ATA increments Yes No Do not exceed 40 txs D/C HBO Yes No tcPO2 in excess of 200mmHg? tcPO2 > 200mmHg? Maintain at 2.0 ATA Repeat tcPO2 at 1.0 ATA at 14 txs Values 40mmHg, or greater Yes No Hold HBO No Standard care Continue HBO Repeat tcPO2 at 1.0 ATA as indicated Hold HBO at 40mmHg Yes Restart HBO 5 – 10 txs Continued healing? Hold HBO Continued healing? Yes No tcPO2 > 200mmHg? Do not exceed 2.5 ATA Deterioration No Yes Hold HBO: Further diagnostic testing Weekly follow up Schedule follow up Yes No Continued healing?