Arterialized ear lobe blood samples for blood gas tensions

doi:10.1016/0007-0971(76)90042-5

British Journal of Diseases of the Chest

Volume 70, 1976, Pages 263-268

https://doi.org/10.1016/0007-0971(76)90042-5 Get rights and content

Abstract

The accuracy of arterialized blood samples both at rest and during exercise is described in comparison to simultaneous arterial blood samples. The technique was found to be reliable and sufficiently accurate for clinical exercise testing, with no significant differences for Po₂ or Pco₂ between the two methods.

References (2)

S. Godfrey et al.
Ear lobe blood samples for blood gas analysis at rest and during exercise
Br. J. Dis. Chest
(1971)
J. MacIntyre et al.
Use of capillary blood in measurement of arterial Po₂
Br. med. J.
(1968)

Cited by (60)

Elevated exercise ventilation in mild COPD is not linked to enhanced central chemosensitivity
2021, Respiratory Physiology and Neurobiology
Citation Excerpt :
Subsequently, a blood sample was drawn into a preheparinized capillary tube, placed on ice, and duplicate samples were analyzed immediately (ABL, Radiometer, Copenhagen, Denmark). This non-invasive method is considered an accurate estimation of arterial PO2 and PCO2 (Spiro and Dowdeswell, 1976). Central chemoreceptor characeristics were then evaluated by examining the ventilatory response to hypercapnia, using the Duffin’s modified CO2 rebreathing test, as previously described (Duffin et al., 2000; Jensen et al., 2005a; Preston et al., 2009).
The purpose of this study was to determine if altered central chemoreceptor characteristics contributed to the elevated ventilation relative to carbon dioxide production (V̇_E/V̇CO₂) response during exercise in mild chronic obstructive pulmonary disease (COPD).
Twenty-nine mild COPD and 19 healthy age-matched control participants undertook lung function testing followed by symptom-limited incremental cardiopulmonary exercise testing . On a separate day, basal (non-chemoreflex) ventilation (V̇_EB), the central chemoreflex ventilatory recruitment threshold for CO₂ (VRTCO₂), and central chemoreflex sensitivity (V̇_ES) were assessed using the modified Duffin’s CO₂ rebreathing method. Resting arterialized blood gas data were also obtained.
At standardized exercise intensities, absolute V̇_E and V̇_E/V̇CO₂ were consistently elevated and the end-tidal partial pressure of CO₂ was relatively decreased in mild COPD versus controls (all p < 0.05). There were no between-group differences in resting arterialized blood gas parameters, basal V̇_E, VRTCO₂, or V̇_ES (all p > 0.05).
These data have established that excessive exercise ventilation in mild COPD is not explained by altered central chemosensitivity.
Comparison of portable oxygen concentrators in a simulated airplane environment
2013, Respiratory Medicine
Citation Excerpt :
In our study all POCs delivered enough oxygen to increase the PaO2 of our subjects by at least 1.40 kPa (10 mmHg). We chose a difference of 10 mmHg to ensure that the change of pO2 was meaningful, as repeated measurements of pO2 from an arterialized ear lobe sample have been found to differ by a mean of 0.99 ± 0.63 mmHg and reflect arterial pO2 with a mean difference of 0.95 ± 3.05 mmHg.4 However a patient would need to test his or her personal oxygen demand according to guidelines to ensure clinical usefulness.5
Portable oxygen concentrators (POC) are highly desirable for patients with lung disease traveling by airplane, as these devices allow theoretically much higher travel times if additional batteries can be used. However, it is unclear whether POCs produce enough oxygen in airplanes at cruising altitude, even if complying with aviation regulations.
We evaluated five frequently used POCs (XPO2 (Invacare, USA), Freestyle (AirSep C., USA), Evergo (Philipps Healthcare, Germany), Inogen One (Inogen, USA), Eclipse 3 (Sequal, USA)) at an altitude of 2650 m (as simulated airplane environment) in 11 patients with chronic obstructive lung disease (COPD) and compared theses POCs with the standard oxygen system (WS120, EMS Ltd., Germany) used by Lufthansa.
Oxygen was delivered by each POC for 30 min to each patient at rest, blood gases were then drawn from the arterialized ear lobe. All POCs were able to deliver enough oxygen to increase the PaO₂ of our subjects by at least 1.40 kPa (10 mmHg). However, to achieve this increase, the two most lightweight POCs (Freestyle and Invacare XPO2) had to be run at their maximum level. This causes a significant reduction of battery life. The three other POCs (EverGo, Inogen One, Eclipse 3) and the WS120 were able to increase the PaO₂ by more than 2.55 kPa (20 mmHg), which provides extra safety for patients with more severe basal hypoxemia.
When choosing the right oxygen system for air travel in patients in COPD, not only weight, but also battery life and maximum possible oxygen output must be considered carefully.
Detection of disturbances in pulmonary gas exchanges during exercise from arterialized earlobe PO<inf>2</inf>
2011, Respiratory Physiology and Neurobiology
Blood sampling from the arterialized earlobe is widely used in clinical exercise testing but Fajac et al. (1998) (Eur. Respir. J. 11, 712–715) have shown that arterialized $P_{O_{2}} (P c_{C O_{2}})$ is not a valid surrogate for $P a_{O_{2}}$ . In the present study, in order to detect disturbances in pulmonary gas exchanges during clinical exercise testing from the alveolar-arterial gradient of $P_{O_{2}}$ ( $P {[A_{i} a]}_{O_{2}}$ ), a correction factor for $P c_{O_{2}}$ was validated from data on a large cohort (107 patients at one or two levels of exercise: 172 pairs of samples). Pulmonary gas exchanges and pH, $P_{O_{2}}$ , $P_{C O_{2}}$ , $P A_{i O_{2}}$ and $P {(A_{i} a)}_{O_{2}}$ from arterial and arterialized blood were measured or computed. Arterial and arterialized pH and $P_{C O_{2}}$ (and thus $P A_{i O_{2}}$ ) were similar but $P c_{O_{2}}$ was lower than arterial $P_{O_{2}} (P a_{O_{2}})$ . However, when corrected for the systematic bias between $P a_{O_{2}}$ and $P c_{O_{2}}$ , which increased with $P c_{O_{2}}$ , $P c_{O_{2}}$ adequately detected disturbances in pulmonary gas exchanges with a very high sensibility and specificity (predictive values of a negative or positive test ∼95%).
Validity of arterialized earlobe blood gases at rest and exercise in normoxia and hypoxia
2010, Respiratory Physiology and Neurobiology
The purpose of this study was to compare arterial and arterialized blood gases during normoxic and hypoxic exercise. In the same conditions, earlobe pulse oximetry O₂ saturation ( $S p_{O_{2}}$ ) was compared to arterial oxygen saturation ( $S a_{O_{2}}$ ). Ten men performed incremental cycle ergometer tests, in normoxia and hypoxia ( $F I_{O_{2}} = 0.127$ ). Blood samples were drawn simultaneously from the radial artery and pre-warmed earlobe capillary blood of subjects at rest, submaximal and near maximal exercise. R² between the two samples were 0.99 for $P_{O_{2}}$ and $S_{O_{2}}$ , 0.86 for $P_{C O_{2}}$ and 0.97 between $S p_{O_{2}}$ and $S a_{O_{2}}$ . Earlobe $P_{O_{2}}$ mean was 4.4 ± 3.6 mmHg lower than $P a_{O_{2}}$ in normoxia but in hypoxia only 1.1 ± 2.2 mmHg low. The mean difference were low in normoxia between $S a_{O_{2}}$ and $S p_{O_{2}}$ and increased in hypoxia, were acceptable for $P_{C O_{2}}$ , $S_{O_{2}}$ , pH in all conditions. In conclusion, except for $P_{O_{2}}$ in normoxia, pre-warmed earlobe capillary blood is a good substitute to arterial blood to allow measurement of blood gas values in normoxia and hypoxia at rest and exercise.
Unilateral Extrapulmonary Airway Bypass in Advanced Emphysema
2010, Annals of Thoracic Surgery
Citation Excerpt :
The primary outcome measure was change in RV to TLC ratio at 3 months. Lung function and arterialized earlobe gases [17] were measured in line with European Respiratory Society guidelines using standard equipment. The incremental shuttle walking test was performed using the method of Singh [18], whereas cycle ergometry used the protocol previously elaborated by us [8]; maximal workload was determined at the screening visit and endurance at 70% of this workload was then measured subsequently.
Gas trapping in emphysema results in resting and dynamic hyperinflation. We tested the hypothesis that a direct connection between the lung parenchyma and the atmosphere could increase expiratory flow and thereby potentially improve dyspnea through the relief of gas trapping.
Ex vivo we studied 7 emphysematous lungs and 3 fibrotic lungs (as controls) and measured expiratory flow before and after airway bypass insertion during a forced maneuver in an artificial thorax. Pilot studies were conducted in vivo in 6 patients with advanced emphysema using a size 9 endotracheal tube as a bypass surgically placed through the chest wall into the upper lobe.
In the ex vivo emphysematous lungs the volume expelled during a forced expiratory maneuver increased from 169 to 235 mL (p < 0.05). In the in vivo group 4 patients retained the bypass tube for 3 months or more; total lung capacity was reduced, and the forced expiratory volume in 1 second increased by 23% (mean percent predicted at baseline versus 3 months, 24.4% versus 29.5%).
An extrapulmonary airway bypass increases expiratory flow in emphysema. This may be a useful approach in hyperinflated patients with homogeneous emphysema.
Depression and its relationship with poor exercise capacity, BODE index and muscle wasting in COPD
2009, Respiratory Medicine
Citation Excerpt :
Spirometry was done according to the ATS/ERS Standardization Guideline27 using a Jaeger MasterScreen spirometer (Jaeger Ltd, Hoechberg, Germany). Earlobe capillary blood gases were measured according to the method described by Spiro and Dowdeswell28 using a Radiometer analyzer (Radiometer Medical A/S, Copenhagen, Denmark). Exercise capacity was measured using the 6-minute walk test (6MWT) according to the ATS guideline.29
The prevalence of depression in stable COPD patients varies markedly, possibly because of use of different scales. We aimed to assess depression using 2 different depression scales and to examine the association between depression and poor exercise performance, BODE index and muscle wasting in clinically stable COPD patients.
122 stable COPD patients were assessed with the Centre for Epidemiologic Studies Depression Scale (CES-D) and the Brief Assessment Schedule Depression Cards (BASDEC). We also assessed patients with spirometry, bioelectrical impedance analysis, 6-minute walk distance (6MWD), St George's Respiratory Questionnaire (SGRQ) and MRC dyspnoea and Borg scales.
The CES-D and BASDEC scales detected almost similar prevalence rates of depression (21% vs 17%) with a Kappa coefficient of 0.68, p < 0.0001. The BASDEC scale detected more depression in women and was more closely associated with dyspnoea than the CES-D. COPD severity was associated with depression when using BODE scores but not when GOLD categories were used. Each of the CES-D and BASDEC depression scores were associated with 6MWD after adjusting for FEV₁% predicted, gender, age and pack-years (p = <0.0001 and 0.001, respectively). Also, patients with a 6MWD < 350 scored significantly higher on both depression scales. Wasted patients appeared to have higher depression scores, but the difference was statistically insignificant.
The administration of different depression scales may affect some of the characteristics of depressed patients rather than the prevalence rate of depression. Depression was associated with poor exercise performance and BODE index in COPD.

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^∗: Present address: Division of Respiratory Diseases RM-12, University of Washington, Seattle, Washington 98195, USA.

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General articleArterialized ear lobe blood samples for blood gas tensions

Abstract

Br. J. Dis. Chest

Use of capillary blood in measurement of arterial Po2

Br. med. J.

General article
Arterialized ear lobe blood samples for blood gas tensions

Use of capillary blood in measurement of arterial Po₂