Am J Vet Res. 2024 Dec 20:1-10. doi: 10.2460/ajvr.24.08.0242. Online ahead of print.
ABSTRACT
OBJECTIVE: To assess the accuracy of a flash glucose monitoring system (FGMS; FreeStyle Libre 2) in healthy dogs during isoflurane general anesthesia.
METHODS: 6 purpose-bred Beagle dogs underwent 3 anesthetic events, 1 week apart, in a randomized crossover study. 1 of 3 mean arterial blood pressure (MAP) states were induced under isoflurane anesthesia (hypotension [MAP, ≤ 60 mm Hg], normotension [MAP, 80 to 120 mm Hg], and hypertension [MAP, ≥ 120 mm Hg]) for 40 minutes. Interstitial glucose was collected from an FGMS (applied to the dog's neck prior to anesthesia) at 0, 5, 10, 20, 30, and 40 minutes from stabilization within targeted MAP range. Whole-blood samples were collected from a lateral saphenous vein for plasma glucose measurement (blood glucose gold standard; BGGS) and via marginal lip mucosal puncture for point-of-care glucose measurement (blood glucose point-of-care; BGPOC). Shrout-Fleiss intraclass correlation and Bland-Altman analysis were performed. Accuracy was determined using human International Organization for Standardization criteria, including Parkes consensus error grid analysis.
RESULTS: Interstitial glucose strongly correlated with BGGS and BGPOC (intraclass correlation, 0.962 and 0.953, respectively). Interstitial glucose measured higher than BGGS (median[IQR] difference 9[-2 to 20] g/dL) and lower than BGPOC (-27[-37 to -11] g/dL). Interstitial glucose BGGS increased as MAP decreased. 62.1% and 63.3% of interstitial glucose measurements were within ± 15 mg/dL when BGGS ≤ 100 mg/dL and within ± 15% of BGGS when > 100 mg/dL, respectively. However, 100% were within zones A and B of error grid analysis.
CONCLUSIONS: Despite not meeting International Organization for Standardization standards, the FreeStyle Libre 2 demonstrated clinical accuracy for monitoring glucose concentrations in anesthetized dogs.
CLINICAL RELEVANCE: The application of an FGMS before anesthesia may be useful for monitoring at-risk patients perioperatively.
PMID:39705805 | DOI:10.2460/ajvr.24.08.0242