In contrast to their study, our study assessed arterial samples as opposed to peripheral venous samples; arterial samples are fully ‘mixed’ and less apt to regional error (e.g. tourniquet effects during phlebotomy, differences in limb flow and oxygen consumption etc.). We were also able to assess the performance of base deficit. A review of previous studies’ assessment of BD, AG, and ACAG for the diagnosis of hyperlactatemia is provided in Table ​Table55. Table 5 Summary of previous studies The implications of these data are noteworthy. Because elevated serum lactate levels identify patients who are

at high risk of death and may identify Inhibitors,research,lifescience,medical patients in shock before they become hypotensive (a condition called cryptic shock), early

recognition and treatment of hyperlactatemia is critical, and likely improves mortality.[7] In order to institute appropriate therapy as timely as possible, screening tests for shock should offer as early a warning as possible, well Inhibitors,research,lifescience,medical before the serum lactate rises to 4.0–5.0 mmol/L. For these reasons, the routine use of AG, BD, and ACAG as screening tests to determine the presence or absence of hyperlactatemia, in our opinion, is unacceptable and potentially harmful. While it is true that the AG and BD detect the presence of hyperlactatemia Inhibitors,research,lifescience,medical more effectively as the threshold value for lactate is raised (serum lactate > 4.0 mmol/L), waiting to diagnose hyperlactatemia by allowing the level to rise may delay appropriate intervention. An ACAG < 10 meq/L appears to effectively rule out the presence of hyperlactatemia, Inhibitors,research,lifescience,medical but the serum albumin and serum electrolytes must be cotemporaneous and from the same sample in order for that relationship to be valid. Given that Inhibitors,research,lifescience,medical accurate and rapid serum lactate concentration measurement is now widely available to all major hospitals (central labs and/or point of service testing), serum lactate concentrations should be routinely measured upon admission to the ICU, for many patients in the emergency

department, and in our opinion should be considered an index laboratory measure. Serum lactate remains an assay that must be requested separately in most ICUs and emergency departments; therefore, a clinician must actively ask for this test (Table ​(Table1).1). Further, the use of anion gap and base deficit to diagnose the presence or absence of hyperlactatemia is still commonly taught to medical students and physicians in training. below As clinicians and teachers, we need to correct this misperception in order to identify patients with hyperlactatemia promptly. In this study, the shortcomings of using the AG to assess metabolic acidosis were exposed. As expected, the sensitivity of anion gap improves when the anion gap is corrected for albumin (ACAG). However, the selleck products specificity of the ACAG remained low. The reason for this is illustrated in Figure ​Figure11 and Figure ​Figure2.2.