a ssessment of an earlobe arterialized blood collector for use in microgravity
DESCRIPTION
A ssessment 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. - PowerPoint PPT PresentationTRANSCRIPT
AAssessment of an Earlobe Arterialized ssessment of an Earlobe Arterialized Blood Collector for use in MicrogravityBlood Collector for use in Microgravity
Thais Russomano* Thais Russomano* Marlise A dos Santos* Marlise A dos Santos*
João Castro* João Castro* John Whittle** John Whittle** Simon Evetts** Simon Evetts** John Ernsting** John Ernsting**
*Microgravity Laboratory/IPCT-PUCRS, Brazil
**Aerospace Medicine Group, King´s College London, UK
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.
Background
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.
Aim
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
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 non-medical personnel.
Potential Usage Hospital based research
Hospital, clinic, rural center and university research.Aero medical and transport use. ISS and other space missions.
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 non-medical 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 non-medical 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 non-medical 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 non-medical 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
Blade module
Capillary tube module
Capillary tube
Body (module housing)
Ophthalmic blade
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
MethodHead Down Tilt to partially replicate the
effects of microgravity
Results
Blood Gas Data for Simultaneous Radial Artery and Earlobe Arterialized Blood Samples
Radial arteryMean SD (range)
Arterialized EarlobeMean 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 arteryMean SD (range)
Arterialized EarlobeMean 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 arteryMean SD (range)
Arterialized EarlobeMean 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 arteryMean SD (range)
Arterialized EarlobeMean 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 arteryMean SD (range)
Arterialized EarlobeMean 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 Mean ( SD)
PO2
mmHg
PCO2
mmHg Langlands & Wallace
(1965) (n=16)
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)
Present study (n=6)
0.25(1.25)
-1.0(0.75)
Study Author
Discussion
Arterilaized Capillary- Arterial Mean ( SD)
PO2
mmHg
PCO2
mmHg Langlands & Wallace
(1965) (n=16)
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)
Present study (n=6)
0.25(1.25)
-1.0(0.75)
Study Author
Discussion
Arterilaized Capillary- Arterial Mean ( SD)
PO2
mmHg
PCO2
mmHg Langlands & Wallace
(1965) (n=16)
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)
Present study (n=6)
0.25(1.25)
-1.0(0.75)
Study Author
Discussion
Arterilaized Capillary- Arterial Mean ( SD)
PO2
mmHg
PCO2
mmHg Langlands & Wallace
(1965) (n=16)
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)
Present study (n=6)
0.25(1.25)
-1.0(0.75)
Study Author
Discussion
Arterilaized Capillary- Arterial Mean ( SD)
PO2
mmHg
PCO2
mmHg Langlands & Wallace
(1965) (n=16)
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)
Present study (n=6)
0.25(1.25)
-1.0(0.75)
Study Author
Discussion
Arterilaized Capillary- Arterial Mean ( SD)
PO2
mmHg
PCO2
mmHg Langlands & Wallace
(1965) (n=16)
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)
Present study (n=6)
0.25(1.25)
-1.0(0.75)
Study Author
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.
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Results
Individual Data