POINT-OF-CARE TESTING CRITICAL LIMITS
Point-of-Care Testing (POCT) Critical Limits By Kami Osher and Gerald J. Kost MD, PhD, MS, FADLM
T
he urgent communication of life-threatening test results is vital for patient safety, enabling rapid, potentially life-saving interventions. Unlike traditional laboratory testing, point-of-care testing (POCT) delivers rapid diagnostic results directly at or near the patient’s site. Healthcare institutions set thresholds for dangerously abnormal results
to guide immediate treatment. These tables display large-scale research by Kami Osher and Gerald J. Kost, MD, PhD, MS, FADLM, published in 2026 in Diagnostics (Basel), involving 417 hospitals across all 50 states and Washington, D.C., including university hospitals and affiliates, heart centers, and trauma centers.1
Table 1. Critical limits for point-of-care clinical chemistry tests.1 Measurand
Number of Hospitals (%)
Units
Low Mean (SD)
Low Median (Range)
High Mean (SD)
High Median (Range)
1.A. Adults Glucose
73 (17.5)
mg/dL
50.3 (4.9)
50 (40–70)
467.7 (60.5)
450 (200–600)
mmol/L
2.8 (0.3)
2.8 (2.2–3.9)
26 (3.4)
25 (11.1–33.3)
Ionized calcium
21 (5)
mmol/L
0.66 (0.17)
0.75 (0.50–1.00)
1.65 (0.10)
1.60 (1.40–1.75)
Potassium
20 (4.8)
mmol/L
2.9 (0.2)
3 (2.5–3)
6.1 (0.2)
6 (6–6.5)
Sodium
18 (4.3)
mmol/L
123.6 (3)
126 (120–126)
156.7 (2.4)
155 (155–160)
CO2 content
17 (4.1)
mmol/L
10.7 (0.6)
11 (10–12)
40 (1.9)
39 (39-45)
Lactic Acid
14 (3.4)
mmol/L
…
…
3.6 (0.6)
3.9 (2–4)
11 (2.6)
mg/dL
Calcium
6.5 (0.2)
6.6 (6–6.6)
13 (0.3)
12.9 (12.9–14)
mmol/L
1.64 (0.05)
1.65 (1.5–1.65)
3.25 (0.08)
3.23 (3.23–3.5)
…
…
3.9 (0)
3.9 (3.9–3.9)
Venous Lactic Acid
10 (2.4)
mmol/L
1.B. Newborns
Glucose
62 (14.9)
mg/dL
44.7 (5)
45 (40–54)
227.7 (87)
200 (125–500)
mmol/L
2.5 (0.3)
2.5 (2.2–3)
12.6 (4.8)
11.1 (6.9–27.8)
Ionized calcium
18 (4.3)
mmol/L
0.86 (0.05)
0.90 (0.80–0.90)
1.41 (0.14)
1.30 (1.30–1.60)
Potassium
15 (3.6)
mmol/L
3 (0.1)
3 (2.8–3)
6.8 (0.5)
7.1 (6–7.1)
Sodium
14 (3.4)
mmol/L
127.5 (4.3)
130 (120–130)
151.1 (2.9)
150 (150–160)
CO2 content
12 (2.9)
mmol/L
11 (0.4)
11 (10–12)
39.2 (0.4)
39 (39–40)
11 (2.6)
mg/dL
Calcium
6.9 (0.3)
7 (6–7)
13 (0.3)
12.9 (12.9–14)
mmol/L
1.73 (0.08)
1.75 (1.5–1.75)
3.25 (0.08)
3.23 (3.23–3.5)
10
mg/dL
…
…
17.9 (0)
17.9 (17.9–17.9)
(2.4)
µmol/L
…
…
306.1 (0)
306.1 (306.1–306.1)
Bilirubin Abbreviation: SD, standard deviation.
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6/12/26 12:50 PM