Reliability of point-of-care hematocrit, blood gas, electrolyte, lactate and glucose measurement during cardiopulmonary bypass

Abstract

The GEM Premier 3000 analyser seems to be suitable for point-of-care testing of electrolytes, metabolites, and blood gases during cardiopulmonary bypass. However, its downward bias in hematocrit values below 30% suggests that using the GEM Premier 3000 as a transfusion trigger leads to overtreatment with packed red cells.

Performance of Point-of-Care Diagnostics for Glucose, Lactate, and Hemoglobin in the Management of Severe Malaria in a Resource-Constrained Hospital in Uganda

“…18 Upward adjustment of a treatment threshold (e.g., to~5 mmol/L) based on the instrument bias might be considered and would have captured all cases of hypoglycemia in our series. Previous studies comparing the i-STAT glucose 12 and the One Touch Ultra instruments 3,6,8 to reference standards have generally shown a high level of accuracy and tighter precision than suggested by our findings, perhaps related to greater variability under field conditions of either or both instruments.…”

“…Treatment of anemia based on clinical judgment would, therefore, result in a large number of unnecessary transfusions compared with a protocol guided by point-of-care testing. Previous studies in the context of cardiopulmonary bypass surgery have found systematic errors caused by alterations in plasma proteins and electrolytes from the conductivity-based i-STAT measurement compared with reference methods 12,21 ; however, our patients were managed with cautious administration of fluids and electrolytes, 22 such that no significant bias was observed. Variability reported in previous studies (±20 g/L) seems to be lower than in our study, perhaps related to the tightly regulated artificial conditions used for testing.…”

“…The test performance characteristics in these contexts have been well-described. [3][4][5][6][7][8][9][10][11][12][13] Hypoglycemia and anemia are common complications of malaria that require laboratory diagnosis, because clinical assessment is an unsatisfactory substitute. Furthermore, lactate level at admission is an important prognostic indicator in severe malaria.…”

Downward bias of conductivity based point-of-care hemoglobin measurement compared with optical methods

“…The Hb/Hct is measured via the following principle: when a low-frequency current is incurred on the blood sample, the non-conductive cell membranes of red blood cells cannot conduct the current, meaning that a higher number of red blood cells results in a lower conductivity; such difference in conductivities is used to measure the Hb/Hct [2,9]. Again, the entire test requires only a few minutes, which makes POC ABGA useful in situations where simple and quick testing is demanded, such as for patients during a surgery [10].…”

Point-of-care testing: where is the evidence? A systematic survey

“…Blood gas Arora [66] 2011 Prospective USA 516 SN, SP, PPV, NPV Bailey [67] 1998 Prospective USA 222 NR Beneteau Burnat [68] 2004 Experimental France 20 NR Beneteau Burnat [69] 2008 Experimental France NR NR Chance [70] 2000 Experimental USA NR NR Coplin [71] 1998 Prospective USA 195 SN, SP Dohgomori [72] 2004 Prospective Japan 27 NR Frasca [73] 2011 Prospective France 471 NR Gayat [74] 2001 Prospective France 200 NR Gehring [75] 2002 Experimental Germany 450 NR Grosse [76] 2010 Prospective Switzerland NR NR Halpern [77] 1998 Prospective USA NR NR Hinkelbein [78] 2008 Prospective Germany 170 NR Jacobs [79] 1993 Experimental USA 259 NR Jain [80] 2009 Cohort USA 200 NR Kilgore [81] 1998 Prospective USA NR NR Kulkani [82] 2005 Prospective Australia NR NR Leino [83] 2011 RCT Finland 60 NR Lindemans [84] 1999 Experimental Netherlands NR NR Ng [85] 2000 Experimental USA NR NR Papadea [86] 2002 Experimental USA NR NR Petersen [87] 2008 Prospective USA 114 NR Prause [88] 1997 Experimental Austria NR NR Schlebush [89] 2001 Experimental Germany NR NR Sediame [90] 1999 Experimental France 92 NR Steinfelder Visscher [91] 2006 Prospective Netherlands 127 NR Thomas [92] 2009 Cohort USA 446 NR Walton [93] 2003 Experimental USA 59 NR Wax [94] 2007 Retrospective USA NR NR Zaman [95] 2001 experimental Belgium 20 NR LR+, positive likelihood ratio; LR-, negative likelihood ratio; NPV, negative predictive value; NR, not reported; PPV, positive predictive value; PTH, parathyroid hormone SN, sensitivity; SP, specificity.…”