Capillary blood gas – a more “patient friendly” alternative to

arterial blood gas?

S. Richter, C. Kerry, N. Hassan & A. Chari, University of Oxford

Arterial sample Capillary sample

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Your vote:

Blood Gas Sampling in

Germany

arterialise

collect

analyse

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1. Do patients prefer CBG over ABG?

2. Are CBGs as accurate as ABGs?

3. How does clinical contextinfluence CBG accuracy?

Systematic review

• Human AdultsP

• ABG I

• Earlobe CBGC• pO2, pCO2, pH, sO2

• Patient preferenceO

Reported in English

Search summary

Irrelevant: 515

Articles for full text review after screening titles and abstracts: 62

Total no. of studies included for systematic review: 31

Not eligible:

Incorrect sampling site: 13

No or insufficent information (e.g.

meeting abstract/letter/ editoral): 11

Wrong language: 3

Reviews: 2

Same article also published in different

journal: 2

TOTAL: 31

After removal of duplicates: 577

Duplicates: 198

No. of records identified through database searching

EMBASE: 74

PubMed: 309

Web of Knowledge: 383

Hand Search: 9

TOTAL: 775

1. Do patients prefer CBG over ABG?

ABG preferred

CBG preferred

2. Are CBGs as accurateas ABGs?

All 31 studies

Primary data for PO2 – 12 studies

n = 203r = 0.990p < 0.001

Normal range OUH= 90 – 120 mmHg

Primary data for PO2 – 12 studies< 150mmHg

n = 149r = 0.940p = 0.646

CBG reliable in relevant pO2 range forn= 149

but further evidence needed

3. How does clinical context influence CBG accuracy?

Clinical Context

PO2 in mmHg

No of SamplesWeighted MeanDifference SD SE

Lung Disease 325 15.666 93.922 5.210

Normal 165 6.404 28.794 2.242

Shocked 310 2.461 28.747 1.633

Peri-operative 96 0.156 7.907 0.807

ALL DATA 1091 7.123 102.904 3.115

Conclusion

1. Patients prefer CBG

2. CBG as accurate as ABG

– sO2, pCO2, pH same

– pO2 reliable < 150 mm Hg more evidence

3. Reliable in various clinical contexts except severe hyperoxia

References I1 Christof.C & Miller, J. M. CLINICAL USE AND LIMITATIONS OF ARTERIALIZED CAPILLARY BLOOD FOR PO2 DETERMINATION. American Review of Respiratory

Disease 98, 653-& (1968).

2 Cooper, E. A. & Smith, H. INDIRECT ESTIMATION OF ARTERIAL PCO2. Anaesthesia 16, 445-&, doi:10.1111/j.1365-2044.1961.tb13425.x (1961).

3 Dall'Ava-Santucci, J., Dessanges, J. F., Dinh Xuan, A. T. & Lockhart, A. Is arterialized earlobe blood PO2 an acceptable substitute for arterial blood PO2? EurRespir J 9, 1329-1330 (1996).

4 Eaton, T., Rudkin, S. & Garrett, J. E. The clinical utility of arterialized earlobe capillary blood in the assessment of patients for long-term oxygen therapy. RespirMed 95, 655-660, doi:10.1053/rmed.2001.1118 (2001).

5 Fajac, I. et al. Blood gas measurement during exercise: a comparative study between arterialized earlobe sampling and direct arterial puncture in adults. EurRespir J 11, 712-715 (1998).

6 Godfrey, S., Wozniak, E. R., Courntenay Evans, R. J. & Samuels, C. S. EAR LOBE BLOOD SAMPLES FOR BLOOD GAS ANALYSIS AT REST AND DURING EXERCISE. British Journal of Diseases of the Chest 65, 58-64, doi:10.1016/0007-0971(71)90006-4 (1971).

7 Hofford, J. M., Pell, S. & Dowling, A. S. Arterial blood gas measurements. The clinical usefulness and limitations of arterialized capillary bloods. Delaware medical journal 45, 8-11 (1973).

8 Honarmand, A. & Safavi, M. Prediction of arterial blood gas values from arterialized earlobe blood gas values in patients treated with mechanical ventilation. Indian journal of critical care medicine : peer-reviewed, official publication of Indian Society of Critical Care Medicine 12, 96-101 (2008).

9 Howland, W. S., Murphy, T. W. & Schweizer, O. ESTIMATION OF ACID-BASE OF VENOUS + ARTERIAL BLOOD FROM CAPILLARY SAMPLES. Acta AnaesthesiologicaScandinavica 8, 191-&, doi:10.1111/j.1399-6576.1964.tb00240.x (1964).

10 Knudsen, E. J. & Hansen, P. CARBON DIOXIDE TENSIONS IN NON-ARTERIALISED CAPILLARY AND ARTERIAL BLOOD DURING ANAESTHESIA. Acta Anaesthesiologica Scandinavica 6, 29-&, doi:10.1111/j.1399-6576.1962.tb00101.x (1962).

11 Koch, G. VALIDITY OF PO2 MEASUREMENT IN CAPILLARY BLOOD AS A SUBSTITUTE FOR ARTERIAL PO2. Scandinavian Journal of Clinical & Laboratory Investigation 21, 10-&, doi:10.3109/00365516809076970 (1968).

12 Langlands, J. H. M. & Wallace, W. F. M. Small blood-samples from ear-lobe puncture. A substitute for arterial puncture. Lancet 7407, 315-317 (1965).

13 Laughlin, D. E., Bedell, G. N. & McDonald, J. S. MICROTECHNIQUE FOR MEASUREMENT OF PO2 ARTERIALIZED EARLOBE BLOOD. Journal of Laboratory andClinical Medicine 64, 330-& (1964).

14 Lilienthal, J. L. & Riley, R. L. On the determination of arterial oxygen saturations from samples of "capillary" blood. Jour Clin Invest 23, 904-906, doi:10.1172/jci101565 (1944).

15 Lilienthal, J. L. & Riley, R. L. ON THE ESTIMATION OF ARTERIAL CARBON DIOXIDE FROM SAMPLES OF CUTANEOUS (CAPILLARY) BLOOD. Journal of Laboratory and Clinical Medicine 31, 99-104 (1946).

16 Maas, A. H. J., Kreukniet, J. & Zuijdgee.Lp. MICROSPECTROPHOTOMETRIC DETERMINATION OF HAEMOGLOBIN OXYGEN SATURATION IN HAEMOLYZED ARTERIALIZED CAPILLARY BLOOD. Clinica Chimica Acta 9, 236-&, doi:10.1016/0009-8981(64)90100-7 (1964).

References II17 Maas, A. H. & Vanheijs.An. A COMPARISON OF PH OF ARTERIAL BLOOD WITH ARTERIALISED BLOOD FROM EAR-LOBE WITH ASTRUPS MICRO

GLASSELECTRODE. Clinica Chimica Acta 6, 31-&, doi:10.1016/0009-8981(61)90032-8 (1961).

18 Maas, A. H. & Vanheijs.An. ACCURACY OF MICRO-DETERMINATION OF PCO2 OF BLOOD FROM EAR-LOBE. Clinica Chimica Acta 6, 34-&, doi:10.1016/0009-8981(61)90033-x (1961).

19 Macintyr.J, Norman, J. N. & Smith, G. USE OF CAPILLARY BLOOD IN MEASUREMENT OF ARTERIAL PO2. British Medical Journal 3, 640-& (1968).

20 McEvoy, J. D. S. & Jones, N. L. ARTERIALIZED CAPILLARY BLOOD-GASES IN EXERCISE STUDIES. Medicine and Science in Sports and Exercise 7, 312-315 (1975).

21 Mollard, P. et al. Validity of arterialized earlobe blood gases at rest and exercise in normoxia and hypoxia. Respir Physiol Neurobiol 172, 179-183, doi:10.1016/j.resp.2010.05.017 (2010).

22 Olivia, J. V., Spellman, S., Podgainy, M. & Gittlema.B. EARLOBE CAPILLARY BLOOD FOR ESTIMATING ARTERIAL OXYGEN-TENSION. Jama-Journal of theAmerican Medical Association 223, 1388-1388 (1973).

23 Pitkin, A. D., Roberts, C. M. & Wedzicha, J. A. Arterial earlobe blood gas analysis: An underused technique. Thorax 48, 1068 (1993).

24 Russomano, T. et al. A device for sampling arterialized earlobe blood in austere environments. Aviat Space Environ Med 77, 453-455 (2006).

25 Sadove, M. S., Thomason, R. D. & Jobgen, E. CAPILLARY VERSUS ARTERIAL BLOOD-GASES. Anesthesia and Analgesia 52, 724-727 (1973).

26 Sauty, A., Uldry, C., Debetaz, L. F., Leuenberger, P. & Fitting, J. W. Differences in PO2 and PCO2 between arterial and arterialized earlobe samples. EurRespir J 9, 186-189 (1996).

27 Spiro, S. G. & Dowdeswell, I. R. G. ARTERIALIZED EAR LOBE BLOOD-SAMPLES FOR BLOOD-GAS TENSIONS. British Journal of Diseases of the Chest 70, 263-268, doi:10.1016/0007-0971(76)90042-5 (1976).

28 Torjusse.W. OXYGEN SATURATION IN CAPILLARY BLOOD. Scandinavian Journal of Clinical & Laboratory Investigation 17, 505-&, doi:10.3109/00365516509075367 (1965).

29 Torjusse.W & Nitterha.S. PH AND PCO2 IN CAPILLARY BLOOD FROM EAR-LOBE. Scandinavian Journal of Clinical & Laboratory Investigation 19, 79-&, doi:10.3109/00365516709093484 (1967).

30 Wallman, A. A., Arora, P. L., Allen, H. & Hyde, R. W. COMPARISON OF ARTERIAL OXYGEN TENSION AND ARTERIALIZED CAPILLARY OXYGEN TENSION DURING BREATHING OF ROOM AIR AND 100 PER CENT OXYGEN. American Review of Respiratory Disease 96, 165-& (1967).

31 Yordanov, Y. Comparative researches into the arterial and capillary blood oxygen tension during surgical interventions. (Preliminary communication). Nauchni trudove na Visshiia meditsinski institut, Sofiia 47, 55-59 (1968).

Previous Meta-analysis:

• Zavorsky, G. S., Cao, J., Mayo, N. E., Gabbay, R. & Murias, J. M. Arterial versus capillary blood gases: A meta-analysis. Respiratory Physiology & Neurobiology 155, 268-279,

Questions?

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