Serial Lactate in Clinical Medicine - A Narrative Review.

Background: Blood lactate is commonly used in clinical medicine as a diagnostic, therapeutic and prognostic guide. Lactate's growing importance in many disciplines of clinical medicine and academic enquiry is underscored by the tenfold increase in publications over the past 10 years. Lactate monitoring is presently shifting from single to serial measurements, offering a means of assessing response to therapy and to guide treatment decisions. With the promise of wearable lactate sensors and their potential integration in electronic patient records and early warning scores, the utility of serial lactate measurement deserves closer scrutiny.

Methods: Articles included in this review were identified by searching MEDLINE, PubMed and EMBASE using the term "lactate" alone and in combination with "serial", "point of care", "clearance", "prognosis" and "clinical". Authors were assigned vetting of publications according to their specialty (anesthesiology, intensive care, trauma, emergency medicine, obstetrics, pediatrics and general hospital medicine). The manuscript was assembled in multidisciplinary groups guided by underlying pathology rather than hospital area.

Findings: Lactate's clinical utility as a dynamic parameter is increasingly recognized. Several publications in the last year highlight the value of serial measurements in guiding therapy. Outside acute clinical areas like the emergency room, operating room or intensive care, obtaining lactate levels is often fraught with difficulty and delays.

Interpretation: Measuring serial lactate and lactate clearance offers regular feedback on response to therapy and patient status. Particularly on the ward, wearable devices integrated in early warning scores via the hospital IT system are likely to identify deteriorating patients earlier than having to rely on observations by an often-overstretched nursing workforce.