The Effects of Temperature and Relative Humidity on Point-of-Care Glucose Measurements in Hospital Practice in a Tropical Clinical Setting

Abstract

Inaccuracy of glucose monitoring may derive from test strip, patient, pharmacological, environmental, and other factors. Incorrect results may cause serious harm and change clinical decisions. 2,3 To ensure reliable results, POC devices and test strips should be stored and operated according to manufacturer specifications. In tropical settings, temperature and relative humidity may exceed specified ranges.Our goal was to assess the effects of storage temperature, operating temperature, and operating relative humidity (RH) when ambient conditions in patient ward areas naturally exceeded manufacturer limits because of the tropical setting of Siriraj Hospital. During ISO 22870 4,5 certification inspection, we discovered out-of-limit temperature and RH discrepancies that had to be investigated and corrected. Methods Glucose Meters and Test StripsWe evaluated the photometric SureStep®Flexx meter, SureStep™ Hospital glucose test strips, and control solutions Background: Hospitals in tropical countries experience conditions that exceed manufacturer temperature and humidity limits for point-of-care (POC) glucose reagents. Our goal was to assess the effects of out-of-limits storage temperature, operating temperature, and operating humidity on POC glucose measurement reliability.Methods: Quality control measurements were performed monthly using glucose test strips stored under controlled conditions and in inpatient wards under ambient conditions. Glucose test strips were evaluated in groups organized by operating temperatures of 24-25 (group 1), 28-29 (group 2), and 33-34°C (group 3), and relative humidity (RH) of ≤70 (group A), ~80 (group B), and ~90% (group C). Results:Glucose results for different storage conditions were inconsistent. Measurements at higher operating temperatures had lower values with mean differences of -2.4 (P < .001) and -36.5 (P < .001) mg/dL (28-29 vs 24-25°C), and -3.6 (P < .001) and -37.4 (P < .001) mg/dL (33-34 vs 24-25°C) for low and high control levels, respectively. Measurements at higher RH had lower values with mean differences of -4.0 (P < .001) and -13.2 (P < .001) mg/dL (~80 vs ≤70% RH), and -5.8 (P < .001) and -16.6 (P < .001) mg/dL (~90 vs ≤70% RH) for low and high levels, respectively. Conclusions:High temperature and high RH decreased glucose concentrations for the POC oxidase-based system we evaluated. We recommend that individual hospitals perform stress testing, then determine if maximum absolute differences, which represent highest risk for patients, are clinically significant for decision making by using error grid analysis.

Novelty seeking and reward dependence‐related large‐scale brain networks functional connectivity variation during salience expectancy

“…The SMA mediates network changes related to emotional reactivity when processing content reflecting insecure attachment [Borchardt et al, ], and in controlling internally triggered movements [Elangovan et al, ]. Specifically, it has been proposed that FC between the SMA and brain areas responsive to emotion in others reflects an empathic response to negative emotional stimuli, in which an impulse to act results in an internalized motor response [Pratumvinit et al, ]. Parallel to these findings, salient cues in a paradigm involving mental actions have led to enhanced FC between reward centers and motor cortex [Mendelsohn et al, ], and the SN has been specifically proposed to play a role in motor response planning [Spencer and Rupp, ].…”

Paper-based DPPH Assay for Antioxidant Activity Analysis

“…High humidity can cause a degradation of the reagent in the test strip, such as glucose. 49 We anticipated that the DPPH paper-based devices kept at a lower humidity condition would be more stable for a longer period of time.…”

PSoC-Stat: A single chip open source potentiostat based on a Programmable System on a Chip

“…At the current range used for the measurement of ±8 μA, the PSoC-Stat has resolution of 0.4 mg/dl. At this level most variation in the glucose measurements will be due to differences between glucose strips, and the temperature and humidity changes between measurements [ 53 ]. The PSoC-Stat measurements were well within the 15% accuracy needed for a glucose meter to be approved by the FDA [ 54 ].…”