TY - JOUR
T1 - Agreement between paired blood gas values in samples transported either by a pneumatic system or by human courier
AU - Peter, John Victor
AU - Patole, Shalom
AU - Fleming, Jude Joseph
AU - Selvakumar, Ratnasamy
AU - Graham, Petra L.
PY - 2011/8/1
Y1 - 2011/8/1
N2 - Background: Rapid accurate assessment of metabolic derangements is crucial in the critically ill. We evaluated if arterial blood gas (ABG) samples transported through a pneumatic tube system (PTS) agreed with values transported by a human courier. Methods: In this prospective study of 50-paired ABG samples, the couriered reference ABG was compared with those transported by PTS. Agreement was summarised by the mean difference with 95% limits of agreement (LOA) and Lin's concordance correlation (pc). Results: The mean (±SD) time from sampling to analysis was 35.7±23.2 (courier) and 38.6±22.1 (PTS) minutes. Agreement was good between courier and PTS for pH, PaCO 2, bicarbonate, oxygen saturation and PaO 2 values (pc>0.97). Although the mean difference in PaO 2 values between PTS and courier was small (-0.9 mm Hg) and the agreement was good, individual differences were clinically significant (95% LOA -40.8 to 39.0). For PaO 2 <160 mm Hg, analysis of PTS samples yielded erroneously high PaO 2 values and vice versa for PaO 2>160 mm Hg compared to manual courier. This suggested exaggerated oxygen movement between the blood sample and air in the PTS. Conclusions: In this study, analysis of samples transported through the PTS resulted in clinically unacceptable PaO 2 values. Delay in transport and analysis of ABG samples should be avoided and samples transported manually if they cannot be assessed on-site.
AB - Background: Rapid accurate assessment of metabolic derangements is crucial in the critically ill. We evaluated if arterial blood gas (ABG) samples transported through a pneumatic tube system (PTS) agreed with values transported by a human courier. Methods: In this prospective study of 50-paired ABG samples, the couriered reference ABG was compared with those transported by PTS. Agreement was summarised by the mean difference with 95% limits of agreement (LOA) and Lin's concordance correlation (pc). Results: The mean (±SD) time from sampling to analysis was 35.7±23.2 (courier) and 38.6±22.1 (PTS) minutes. Agreement was good between courier and PTS for pH, PaCO 2, bicarbonate, oxygen saturation and PaO 2 values (pc>0.97). Although the mean difference in PaO 2 values between PTS and courier was small (-0.9 mm Hg) and the agreement was good, individual differences were clinically significant (95% LOA -40.8 to 39.0). For PaO 2 <160 mm Hg, analysis of PTS samples yielded erroneously high PaO 2 values and vice versa for PaO 2>160 mm Hg compared to manual courier. This suggested exaggerated oxygen movement between the blood sample and air in the PTS. Conclusions: In this study, analysis of samples transported through the PTS resulted in clinically unacceptable PaO 2 values. Delay in transport and analysis of ABG samples should be avoided and samples transported manually if they cannot be assessed on-site.
UR - http://www.scopus.com/inward/record.url?scp=80051717778&partnerID=8YFLogxK
U2 - 10.1515/CCLM.2011.611
DO - 10.1515/CCLM.2011.611
M3 - Article
C2 - 21619479
AN - SCOPUS:80051717778
SN - 1434-6621
VL - 49
SP - 1303
EP - 1309
JO - Clinical Chemistry and Laboratory Medicine
JF - Clinical Chemistry and Laboratory Medicine
IS - 8
ER -