Venous Blood Gas Reference Intervals

Transcription

1 Venous Blood Gas Reference Intervals The NSW Health Pathology approach Andrea Rita Horvath Department of Clinical Chemistry & Endocrinology NSW Health Pathology, Prince of Wales Hospital, Sydney

2 Outline Background Methods Results Transferability of the VBG RIs Conclusions

3 Acknowledgements Kirsty Ress NSW Health Pathology Gus Koerbin NSW Health Pathology Doug Chesher NSW Health Pathology Samarina Musaad NZPOCTQAG / ARQAG Ken Sikaris Melbourne Pathology David Hughes ACT Pathology Robert Flatman Sullivan Nicolaides Pathology Goce Dimeski QLD Pathology Frank Alvaro NSW Health Pathology Joshua Ryan NSW Health Pathology Anthony Diamond NSW Health Pathology Dorra Arvanitis NSW Health Pathology Andrew Sargeant NSW Health Pathology NSWHP Clinical Chemistry Stream and POCT Advisory Group

4 Background NSW Health Pathology Blood Gas Service 338 devices 105 ABL 800 series, 16 ABL 90 flex 15 GEM i-stat

5 Outline Background Methods Results Transferability of the VBG RIs Conclusions

6 Methods Systematic review of the literature RI study Survey of laboratory RIs Consensus of chemical pathologists Clinical consultation and consensus Verification and transferability testing using flag rates and 95 percentile ED population data

7 Outline Background Methods Results Transferability of the VBG RIs Conclusions

8 Systematic literature review : No VBG RI studies in humans

9 Systematic literature review Human studies were only on ABG-VBG differences mostly in sick patients Review No. of studies and disease states* ph HCO3 (mmol/l) Difference (VBG ABG) pco 2 (mmhg) po 2 (mmhg) Lactate (mmol/l) Ress (2016)* 47 (All) Bloom et al (2014) 3-15 (All) Bryne et al (2014) 18 (All) Kelly (2013) 13 (ED) Kelly et al (2010) 3-10 (ED) Lim et al (2010) 6 (COPD) Kelly et al (2006) 3 (DKA) * Median of all studies ED Emergency Department, COPD - Chronic Obstructive Pulmonary Disease, DKA Diabetic Ketoacidosis All No specific disease state included in the study. All disease states were included (e.g. COPD, DKA, healthy, critically ill and emergency department patients).

10 NSW VBG RI study n=216 healthy adult volunteers; 2/3 female, 1/3 male; age: 18-70y (80% 26-56y) Radiometer ABL 800 series blood gas analyser in one laboratory location Safe-PICO syringes for sampling Analyte Median Average Deviation Percentile (Non-coning) Tukey (Non-Para) Dixon-Reed (Non-Para) ph po 2 (mmhg) pco 2 (mmhg) Bicarbonate (mmol/l) Lactate (mmol/l) Sodium (mmol/l) Potassium (mmol/l) Chloride (mmol/l) Ionised Ca (mmol/l)

11 Review by chemical pathologists

12 Review by clinicians Final clinical & laboratory consensus

13 Evolution of the NSWHP VBG RI Analyte RI modelled on ABG-VBG differences NSW RI study NSWHP clin. chem. stream consensus NSWH clinical and laboratory consensus ph po 2 (mmhg) No RI No RI pco 2 (mmhg) Bicarbonate (mmol/l) Lactate (mmol/l) < <2.0 Ionised Ca (mmol/l) NA Sodium (mmol/l) NA Potassium (mmol/l) NA Chloride (mmol/l) NA

14 Every advantage in the past is judged in the light of the final issue From a consequentialist standpoint, a morally right act (or omission from acting) is one that will produce a good outcome, or consequence. Demosthenes

15 Outline Background Methods Results Transferability of the VBG RIs Conclusions

16 Transferability: 95% and flag rates Location NSW (public) ACT (public) VIC (private) QLD (public & private) NZ Instruments 65% Radiometer ABL 90 and 800 series 28% IL/Werfen GEM 5% Abbott i-stat 2% Siemens Rapidpoint 500 N=92,728 adult (>18 yr) inpatient episodes with VBG results 89% ED (n=82,786) 8% ED, ICU, CCU mixed population (n=7,814) 3% non-ed, non-icu wards (n=2,128) Limitations of data/data analysis All (not just single) episodes No age and gender breakdown (but majority is elderly); no exclusion of outliers Suitable for instrument comparison but not for RI verification VIC 7% ACT 25% QLD 5% NZ 5% NSW 58%

17 i-stat Abbott Rapidpoint Siemens ph VBG 95% of ED population - ph Laboratory ABL 800 series Radiometer GEM IL

18 i-stat Abbott Rapidpoint Siemens % of ph Results Flagged ED ED&ICU Non-ED&ICU Non-ED LRL Flagging Rate - ph 50 ph Lower Reference Limit: NSWHP 7.3, NSW RI Study Laboratory NSWHP FR Study FR ABL 800 series Radiometer GEM IL

19 i-stat Abbott Rapidpoint Siemens % of ph Results Flagged URL Flagging Rate - ph 50 ph Upper Reference Limits: NSWHP 7.4, NSW RI Study NSWHP FR Study FR Laboratory ABL 800 series Radiometer GEM IL

20 i-stat Abbott Rapidpoint Siemens pco2 (mmhg) VBG 95% of ED population pco Laboratory ABL 800 series Radiometer GEM IL

21 i-stat Abbott Rapidpoint Siemens % of pco 2 Results Flagged LRL Flagging Rate pco 2 50 pco 2 Lower Reference Limit: NSWHP 40 mmhg, NSW RI Study 38 mmhg NSWHP FR Study FR Laboratory ABL 800 series Radiometer GEM IL

22 i-stat Abbott Rapidpoint Siemens % of pco 2 Results Flagged URL Flagging Rate pco 2 50 pco 2 Upper Reference Limit: NSWHP 50 mmhg, NSW RI Study 61 mmhg NSWHP FR Study FR Laboratory ABL 800 series Radiometer GEM IL

23 i-stat Abbott Rapidpoint Siemens Bicarbonate (mmol/l) VBG 95% of ED population Bicarbonate Laboratory ABL 800 series Radiometer GEM IL

24 i-stat Abbott Rapidpoint Siemens % of Bicarbonate Results Flagged LRL Flagging Rate Bicarbonate 50 Bicarbonate Lower Reference Limit: NSWHP 22 mmol/l, NSW RI Study 23 mmol/l NSWHP FR Study FR Laboratory ABL 800 series Radiometer GEM IL

25 i-stat Abbott Rapidpoint Siemens % of Bicarbonate Results Flagged URL Flagging Rate Bicarbonate 50 Bicarbonate Upper Reference Limit: NSWHP 32 mmol/l, NSW RI Study 31 mmol/l NSWHP FR Study FR Laboratory ABL 800 series Radiometer GEM IL

26 i-stat Abbott Rapidpoint Siemens Lactate (mmol/l) VBG 95% of ED population Lactate Laboratory ABL 800 series Radiometer GEM IL

27 i-stat Abbott Rapidpoint Siemens % of Lactate Results Flagged URL Flagging Rate Lactate 70 Lactate Upper Reference Limit: NSWHP <2 mmol/l, NSW RI Study 3.1 mmol/l NSWHP FR 30 Study FR Laboratory ABL 800 series Radiometer GEM IL

28 i-stat Abbott Rapidpoint Siemens Ionised Ca (mmol/l) VBG 95% of ED population - ica Laboratory ABL 800 series Radiometer GEM IL

29 i-stat Abbott Rapidpoint Siemens % of Ionised Ca Results Flagged LRL Flagging Rate ica ica Lower Reference Limit: NSWHP 1.15 mmol/l, NSW RI Study 1.16 mmol/l NSWHP FR Study FR Laboratory ABL 800 series Radiometer GEM IL

30 i-stat Abbott Rapidpoint Siemens % of Ionised Ca Results Flagged URL Flagging Rate ica ica Upper Reference Limit: NSWHP 1.30 mmol/l, NSW RI Study 1.32 mmol/l NSWHP FR Study FR Laboratory ABL 800 series Radiometer GEM IL

31 i-stat Abbott Rapidpoint Siemens Sodium VBG 95% of ED population - Na 160 NSWHP RI: mmol/l; HRI (serum/plasma): mmol/l Laboratory ABL 800 series Radiometer GEM IL

32 i-stat Abbott Rapidpoint Siemens Potassium (mmol/l) VBG 95% of ED population - K NSWHP RI: mmol/l HRI (serum/plasma): mmol/l; mmol/l (paed. plasma) Laboratory ABL 800 series Radiometer GEM IL

33 i-stat Abbott Rapidpoint Siemens Chloride (mmol/l) VBG 95% of ED population - Cl NSWHP RI: mmol/l; HRI (serum/plasma): mmol/l Laboratory ABL 800 series Radiometer GEM IL

34 Outline Background Methods Results Transferability of the VBG RIs Conclusions

35 Analyte NSW RI study Conclusions The below VBG Reference Intervals are adaptable to all major platforms (ABL, i-stat, GEM, Rapidpoint) after local verification. Electrolytes need further investigation. NSWH clinical and laboratory consensus Comments ph High URL flag rate may need fine tuning Harmonisation Meeting 2018 Recommendations accepted po 2 (mmhg) No RI Recommend ABG accepted pco 2 (mmhg) URL = decision limit to detect COPD. It will flag 20-25% healthy; clinical F/U accepted, with some arguing that this is a decision limit and we should still cite a RI that has a higher URL of ~60 mmhg Bicarbonate (mmol/l) HRI for serum/plasma accepted Lactate (mmol/l) <2.0 Same as ABG RI accepted Ionised Ca (mmol/l) Investigate high flag rate at LRL Sodium (mmol/l) Notable instrument differences?hri for plasma: Potassium (mmol/l) ?HRI for plasma: (paed) or (adults) Chloride (mmol/l) Notable instrument differences?hri for plasma: Suggested to investigate further and look into sampling issues that may explain the high flag rate at the LRL To be discussed further in the blood gas working party To be discussed further in the blood gas working party To be discussed further in the blood gas working party

36 <2.0 * NSWHP RI study NB; po2 RI is not recommended in VBG Proposed NSWHP RI * 22-32

37 References Kelly AM, McAlpine R, Kyle E. Agreement between bicarbonate measured on arterial and venous blood gases. Emergency Medicine. 2004;16(5 6):407-9 Kelly AM. The case for venous rather than arterial blood gases in diabetic ketoacidosis. Emergency Medicine Australasia. 2006;18(1):64-7 Kelly AM. Review article: Can venous blood gas analysis replace arterial in emergency medical care. Emergency Medicine Australasia. 2010;22(6):493-8 Lim BL, Kelly A-M. A meta-analysis on the utility of peripheral venous blood gas analyses in exacerbations of chronic obstructive pulmonary disease in the emergency department. European Journal of Emergency Medicine. 2010;17(5):246-8 Kelly AM. Agreement between arterial and venous blood gases in emergency medical care: a systematic review. Hong Kong Journal of Emergency Medicine. 2013;20(3):166. Bloom BM, Grundlingh J, Bestwick JP, Harris T. The role of venous blood gas in the emergency department: a systematic review and meta-analysis. European Journal of Emergency Medicine. 2014;21(2): Byrne AL, Bennett M, Chatterji R, Symons R, Pace NL, Thomas PS. Peripheral venous and arterial blood gas analysis in adults: are they comparable? A systematic review and meta analysis. Respirology. 2014;19(2): How to Read a Venous Blood Gas (VBG) - Top 5 Tips -