Transcript Assessment of an Arterialised Earlobe Blood Sampler

Assessment of an Earlobe Arterialized
Blood Collector for use in Microgravity
Thais Russomano*
Marlise A dos Santos*
João Castro*
John Whittle**
Simon Evetts**
John Ernsting**
*Microgravity Laboratory/IPCT-PUCRS, Brazil
**Aerospace Medicine Group, King´s College London, UK
Background
There is currently no method of directly measuring
arterial blood gas tensions in space.
Background
There is currently no method of directly measuring
arterial blood gas tensions in space.
An alternative to direct arterial measurement is earlobe
arterialized blood sampling, an accurate technique for
measuring blood gas tensions, which has been in use in
clinical medicine and physiology for more than 30 years
(Lilienthal JL & Riley RL, 1944).
Background
There is currently no method of directly measuring
arterial blood gas tensions in space.
An alternative to direct arterial measurement is earlobe
arterialized blood sampling, an accurate technique for
measuring blood gas tensions, which has been in use in
clinical medicine and physiology for more than 30 years
(Lilienthal JL & Riley RL, 1944).
This technique has not yet been examined in the
microgravity environment due to the risk of
environmental contamination with blood products.
Aim
The aim of the project is to develop a
device and associated procedures that
enable an acceptable estimation of
arterial blood gas tensions and pH to be
conducted accurately and safely in
microgravity.
Introduction
Earlobe Blood Sampling – The Technique
Introduction
Earlobe Blood Sampling – The Technique
The earlobe is rendered hyperemic by the application of
a rubefacient cream containing 1% methyl nicotinate.
Introduction
Earlobe Blood Sampling – The Technique
The earlobe is rendered hyperemic by the application of
a rubefacient cream containing 1% methyl nicotinate.
The skin is then cleaned with an alcohol swab and a
small incision is made in the earlobe.
Introduction
Earlobe Blood Sampling – The Technique
The earlobe is rendered hyperemic by the application of
a rubefacient cream containing 1% methyl nicotinate.
The skin is then cleaned with an alcohol swab and a
small incision is made in the earlobe.
Blood is collected anaerobically via capillary tubes.
Introduction
Earlobe Blood Sampling – The Technique
The earlobe is rendered hyperemic by the application of
a rubefacient cream containing 1% methyl nicotinate.
The skin is then cleaned with an alcohol swab and a
small incision is made in the earlobe.
Blood is collected anaerobically via capillary tubes.
Blood is then analyzed using a blood gas analyzer.
Introduction
Earlobe massage
Earlobe arterialized blood collection
Radial Artery / Arterialised Earlobe Collection
Characteristic
Radial Artery
Sample
Hyperemic Earlobe
Sample
Discomfort
Painful
Pain Free
Potential
Complications
Hematoma
Hemorrhage
Infection (systemic)
Wrist pain
Arterial Spasm
Hemorrhage
Infection (cutaneous)
Ease of Use
Requires trained
medical personnel
Performed by nonmedical personnel.
Potential Usage
Hospital based
research
Hospital, clinic, rural
center and university
research.
Aero medical and
transport use.
ISS and other space
missions.
Characteristic
Radial Artery
Sample
Hyperemic Earlobe
Sample
Discomfort
Painful
Pain Free
Potential
Complications
Hematoma
Hemorrhage
Infection (systemic)
Wrist pain
Arterial Spasm
Hemorrhage
Infection (cutaneous)
Ease of Use
Requires trained
medical personnel
Performed by nonmedical personnel.
Potential Usage
Hospital based
research
Hospital, clinic, rural
center and university
research.
Aero medical and
transport use.
ISS and other space
missions.
Characteristic
Radial Artery
Sample
Hyperemic Earlobe
Sample
Discomfort
Painful
Pain Free
Potential
Complications
Hematoma
Hemorrhage
Infection (systemic)
Wrist pain
Arterial Spasm
Hemorrhage
Infection (cutaneous)
Ease of Use
Requires trained
medical personnel
Performed by nonmedical personnel.
Potential Usage
Hospital based
research
Hospital, clinic, rural
center and university
research.
Aero medical and
transport use.
ISS and other space
missions.
Characteristic
Radial Artery
Sample
Hyperemic Earlobe
Sample
Discomfort
Painful
Pain Free
Potential
Complications
Hematoma
Hemorrhage
Infection (systemic)
Wrist pain
Arterial Spasm
Hemorrhage
Infection (cutaneous)
Ease of Use
Requires trained
medical personnel
Performed by nonmedical personnel.
Potential Usage
Hospital based
research
Hospital, clinic, rural
center and university
research.
Aero medical and
transport use.
ISS and other space
missions.
Characteristic
Radial Artery
Sample
Hyperemic Earlobe
Sample
Discomfort
Painful
Pain Free
Potential
Complications
Hematoma
Hemorrhage
Infection (systemic)
Wrist pain
Arterial Spasm
Hemorrhage
Infection (cutaneous)
Ease of Use
Requires trained
medical personnel
Performed by nonmedical personnel.
Potential Usage
Hospital based
research
Hospital, clinic, rural
center and university
research.
Aero medical and
transport use.
ISS and other space
missions.
Development and Evaluation of a
Earlobe Arterialized Blood Collector
Prototype of the Earlobe Arterialized
Blood (EAB) Collector
Current Prototype of the EAB Collector
Body (module
housing)
Capillary tube
module
Capillary tube
Ophthalmic blade
Blade module
Method
A validation study of the EAB Collector was conducted
in which simultaneous samples of arterial and
arterialized blood were taken from the radial artery and
the earlobe.
Method
A validation study of the EAB Collector was conducted
in which simultaneous samples of arterial and
arterialized blood were taken from the radial artery and
the earlobe.
Six healthy subjects breathed a gas mixture of 12.8% O2
in N2 (equivalent to breathing air at 12,000 feet) during
15 min of head-down tilt.
Method
A validation study of the EAB Collector was conducted
in which simultaneous samples of arterial and
arterialized blood were taken from the radial artery and
the earlobe.
Six healthy subjects breathed a gas mixture of 12.8% O2
in N2 (equivalent to breathing air at 12,000 feet) during
15 min of head-down tilt.
The blood samples were analyzed immediately.
Method
Head Down Tilt to partially replicate the
effects of microgravity
Results
Blood Gas Data for Simultaneous Radial Artery and
Earlobe Arterialized Blood Samples
Radial artery
Mean  SD (range)
Arterialized Earlobe
Mean  SD (range)
pH
(pH Unit)
7.43  0.02 (7.4 – 7.46)
7.43  0.02 (7.4 – 7.46)
PO2
(mmHg)
42.1  3.66 (38 – 47)
42.9  3.88 (37 – 50)
PCO2
(mmHg)
34.1  1.88 (31 – 37)
33.12  2.38 (29 – 37)
SaO2
(%)
79.0  3.85 (75 – 84.5)
79.9  3.29 (74 –85.6)
Results
Blood Gas Data for Simultaneous Radial Artery and
Earlobe Arterialized Blood Samples
Radial artery
Mean  SD (range)
Arterialized Earlobe
Mean  SD (range)
pH
(pH Unit)
7.43  0.02 (7.4 – 7.46)
7.43  0.02 (7.4 – 7.46)
PO2
(mmHg)
42.1  3.66 (38 – 47)
42.9  3.88 (37 – 50)
PCO2
(mmHg)
34.1  1.88 (31 – 37)
33.12  2.38 (29 – 37)
SaO2
(%)
79.0  3.85 (75 – 84.5)
79.9  3.29 (74 –85.6)
Results
Blood Gas Data for Simultaneous Radial Artery and
Earlobe Arterialized Blood Samples
Radial artery
Mean  SD (range)
Arterialized Earlobe
Mean  SD (range)
pH
(pH Unit)
7.43  0.02 (7.4 – 7.46)
7.43  0.02 (7.4 – 7.46)
PO2
(mmHg)
42.1  3.66 (38 – 47)
42.9  3.88 (37 – 50)
PCO2
(mmHg)
34.1  1.88 (31 – 37)
33.12  2.38 (29 – 37)
SaO2
(%)
79.0  3.85 (75 – 84.5)
79.9  3.29 (74 –85.6)
Results
Blood Gas Data for Simultaneous Radial Artery and
Earlobe Arterialized Blood Samples
Radial artery
Mean  SD (range)
Arterialized Earlobe
Mean  SD (range)
pH
(pH Unit)
7.43  0.02 (7.4 – 7.46)
7.43  0.02 (7.4 – 7.46)
PO2
(mmHg)
42.1  3.66 (38 – 47)
42.9  3.88 (37 – 50)
PCO2
(mmHg)
34.1  1.88 (31 – 37)
33.12  2.38 (29 – 37)
SaO2
(%)
79.0  3.85 (75 – 84.5)
79.9  3.29 (74 –85.6)
Results
Blood Gas Data for Simultaneous Radial Artery and
Earlobe Arterialized Blood Samples
Radial artery
Mean  SD (range)
Arterialized Earlobe
Mean  SD (range)
pH
(pH Unit)
7.43  0.02 (7.4 – 7.46)
7.43  0.02 (7.4 – 7.46)
PO2
(mmHg)
42.1  3.66 (38 – 47)
42.9  3.88 (37 – 50)
PCO2
(mmHg)
34.1  1.88 (31 – 37)
33.12  2.38 (29 – 37)
SaO2
(%)
79.0  3.85 (75 – 84.5)
79.9  3.29 (74 –85.6)
Results
The mean difference in PO2 between arterialized
earlobe and arterial samples was 0.25 ( ± 1.25)
mmHg.
Results
The mean difference in PO2 between arterialized
earlobe and arterial samples was 0.25 ( ± 1.25)
mmHg.
Comparison of PCO2 of the arterialized earlobe and
arterial samples showed a mean difference of -1 ( ±
0.75) mmHg.
Results
The mean difference in PO2 between arterialized
earlobe and arterial samples was 0.25 ( ± 1.25)
mmHg.
Comparison of PCO2 of the arterialized earlobe and
arterial samples showed a mean difference of -1 ( ±
0.75) mmHg.
There was no difference between the pH values of
the arterialized earlobe and arterial samples.
Correlations between Arterial and
Earlobe Blood Sample Measurements
r = 0.93
r = 0.94
r = 0.97
r = 0.92
Discussion
Arterilaized Capillary- Arterial
Study Author
Mean ( SD)
PO2
mmHg
PCO2
mmHg
0.62
(4.1)
1.05
(1.6)
Godfrey et al. (1971) (n=8)
2.09
(2.48)
0.65
(1.2)
Spiro & Dowdeswell (1971) (n=11)
-0.72
(1.67)
1.0
(1.91)
Dar et al. (1995) (n=55)
0.675
(4.43)
0.75
(2.25)
0.25
(1.25)
-1.0
(0.75)
Langlands & Wallace
(1965) (n=16)
Present study (n=6)
Discussion
Arterilaized Capillary- Arterial
Study Author
Mean ( SD)
PO2
mmHg
PCO2
mmHg
0.62
(4.1)
1.05
(1.6)
Godfrey et al. (1971) (n=8)
2.09
(2.48)
0.65
(1.2)
Spiro & Dowdeswell (1971) (n=11)
-0.72
(1.67)
1.0
(1.91)
Dar et al. (1995) (n=55)
0.675
(4.43)
0.75
(2.25)
0.25
(1.25)
-1.0
(0.75)
Langlands & Wallace
(1965) (n=16)
Present study (n=6)
Discussion
Arterilaized Capillary- Arterial
Study Author
Mean ( SD)
PO2
mmHg
PCO2
mmHg
0.62
(4.1)
1.05
(1.6)
Godfrey et al. (1971) (n=8)
2.09
(2.48)
0.65
(1.2)
Spiro & Dowdeswell (1971) (n=11)
-0.72
(1.67)
1.0
(1.91)
Dar et al. (1995) (n=55)
0.675
(4.43)
0.75
(2.25)
0.25
(1.25)
-1.0
(0.75)
Langlands & Wallace
(1965) (n=16)
Present study (n=6)
Discussion
Arterilaized Capillary- Arterial
Study Author
Mean ( SD)
PO2
mmHg
PCO2
mmHg
0.62
(4.1)
1.05
(1.6)
Godfrey et al. (1971) (n=8)
2.09
(2.48)
0.65
(1.2)
Spiro & Dowdeswell (1971) (n=11)
-0.72
(1.67)
1.0
(1.91)
Dar et al. (1995) (n=55)
0.675
(4.43)
0.75
(2.25)
0.25
(1.25)
-1.0
(0.75)
Langlands & Wallace
(1965) (n=16)
Present study (n=6)
Discussion
Arterilaized Capillary- Arterial
Study Author
Mean ( SD)
PO2
mmHg
PCO2
mmHg
0.62
(4.1)
1.05
(1.6)
Godfrey et al. (1971) (n=8)
2.09
(2.48)
0.65
(1.2)
Spiro & Dowdeswell (1971)
(n=11)
-0.72
(1.67)
1.0
(1.91)
Dar et al. (1995) (n=55)
0.675
(4.43)
0.75
(2.25)
0.25
(1.25)
-1.0
(0.75)
Langlands & Wallace
(1965) (n=16)
Present study (n=6)
Discussion
Arterilaized Capillary- Arterial
Study Author
Mean ( SD)
PO2
mmHg
PCO2
mmHg
0.62
(4.1)
1.05
(1.6)
Godfrey et al. (1971) (n=8)
2.09
(2.48)
0.65
(1.2)
Spiro & Dowdeswell (1971) (n=11)
-0.72
(1.67)
1.0
(1.91)
Dar et al. (1995) (n=55)
0.675
(4.43)
0.75
(2.25)
0.25
(1.25)
-1.0
(0.75)
Langlands & Wallace
(1965) (n=16)
Present study (n=6)
Discussion
Points of note.
Discussion
Points of note.
• Arterialized blood collection from the
earlobe is virtually pain free.
Discussion
Points of note.
• Arterialized blood collection from the
earlobe is virtually pain free.
• Anaesthetic is not required.
Discussion
Points of note.
• Arterialized blood collection from the
earlobe is virtually pain free.
• Anaesthetic is not required.
• Anaerobic blood collection is possible.
Discussion
Points of note.
• Arterialized blood collection from the
earlobe is virtually pain free.
• Anaesthetic is not required.
• Anaerobic blood collection is possible.
• EAB Collector prevents environmental
contamination.
Conclusion
This limited study suggests that:
Conclusion
This limited study suggests that:
1. Arterialized blood sampled from the
earlobe provides accurate estimations of
arterial blood measurements of PO2, PCO2
and pH during microgravity simulation and in
hypoxia.
Conclusion
This limited study suggests that:
1. Arterialized blood sampled from the
earlobe provides accurate estimations of
arterial blood measurements of PO2, PCO2
and pH during microgravity simulation and in
hypoxia.
2. Blood collection will be possible in
microgravity without environmental
contamination.
Further Studies
1. To validate the EAB Collector during normoxia in
other body positions (sitting and supine);
2. To test the efficiency of the EAB Collector in
microgravity (parabolic flight).*
* Protocol under evaluation by ESA.
Thank you for listening
Questions?
Professor Thais Russomano
[email protected]
or
[email protected]
Results
Individual Data