(41 days)
The i-STAT CG4+ cartridge with the i-STAT 1 System is intended for use in the in vitro quantification of pH, PO2, PCO2, and lactate in arterial or venous whole blood in point of care or clinical laboratory settings.
pH, PO2, and PCO2 measurements are used in the diagnosis, monitoring, and treatment of respiratory disturbances and metabolic and respiratory-based acid-base disturbances.
Lactate measurements are used in (1) the diagnosis and treatment of lactic acidosis in conjunction with measurements of blood acid/base status, (2) monitoring tissue hypoxia and strenuous physical exertion, and (3) diagnosis of hyperlactatemia.
The i-STAT CG4+ test cartridge contains test reagents to analyze whole blood at the point of care or in the clinical laboratory for pH. PO2 (partial pressure of oxygen), PCO2 (partial pressure of carbon dioxide), and lactate. The test is contained in a single-use, disposable cartridge. Cartridges require two to three drops of whole blood which are typically applied to the cartridge using a transfer device.
The i-STAT 1 Analyzer is a handheld, in vitro diagnostic analytical device designed to run only i-STAT test cartridges. The instrument interacts with the cartridge to move fluid across the sensors and generate a quantitative result (within approximately 2 minutes).
The i-STAT 1 System is comprised of the i-STAT 1 analyzer, the i-STAT test cartridges and accessories (i-STAT 1 Downloader/Recharger, electronic simulator and portable printer). The system is designed for use by trained medical professionals at the patient point of care or in the clinical laboratory and is for prescription use only.
Here's a summary of the acceptance criteria and study information for the i-STAT CG4+ Cartridge with the i-STAT 1 System, based on the provided FDA 510(k) summary:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state formal "acceptance criteria" for each performance characteristic in a pass/fail format. Instead, it presents study results and concludes that the device is "substantially equivalent" to predicate devices. However, we can infer some criteria from the reported performance, especially in precision and linearity compared to typical clinical expectations.
| Performance Characteristic | Acceptance Criteria (Implied/Inferred) | Reported Device Performance |
|---|---|---|
| Precision (Aqueous Materials) | Acceptable Total CV% (Specific values for each analyte and level) | pH: Total CV% ranged from 0.03% to 0.07% across 5 levels. |
| PO2: Total CV% ranged from 1.9% to 3.5% across 5 levels. | ||
| PCO2: Total CV% ranged from 1.5% to 3.4% across 5 levels. | ||
| Lactate: Total CV% ranged from 0.4% to 2.7% across 5 levels. | ||
| Precision (Whole Blood) | Acceptable SD and CV% within specified sample ranges for venous and arterial blood | pH (Venous): SDs from 0.0030 to 0.0064, CV% from 0.04 to 0.09. |
| pH (Arterial): SDs from 0.0047 to 0.0060, CV% from 0.06 to 0.08. | ||
| PO2 (Venous): SDs from 0.9 to 12.4, CV% from 0.7 to 3.4. | ||
| PO2 (Arterial): SDs from 0.5 to 8.5, CV% from 1.2 to 4.4. | ||
| PCO2 (Venous): SDs from 0.29 to 0.77, CV% from 0.8 to 1.7. | ||
| PCO2 (Arterial): SDs from 0.37 to 0.90, CV% from 0.5 to 2.1. | ||
| Lactate (Venous): SDs from 0.016 to 0.200, CV% from 1.14 to 2.26. | ||
| Lactate (Arterial): SDs from 0.018 to 0.036, CV% from 0.42 to 2.49. | ||
| Linearity | Demonstrated linearity over the reportable range (e.g., r² > 0.99) | pH: Slope 0.966, Intercept 0.246, r² 0.9983 |
| PO2: Slope 1.005, Intercept -0.196, r² 0.9988 | ||
| PCO2: Slope 1.027, Intercept -1.084, r² 0.9978 | ||
| Lactate: Slope 1.128, Intercept 0.104, r² 0.9966 | ||
| Limit of Quantitation (LoQ) | LoQ to be below the lower limit of the reportable range | pH: Determined LoQ 6.716 (LLR ≤ 7.000) |
| PO2: Determined LoQ 10 mmHg (LLR ≤ 15 mmHg) | ||
| PCO2: Determined LoQ 9.7 mmHg (LLR ≤ 15.0 mmHg) | ||
| Lactate: Determined LoQ 0.27 mmol/L (LLR ≤ 0.30 mmol/L) | ||
| Limit of Blank (LoB) / Limit of Detection (LoD) | LoB and LoD for Lactate to be within acceptable limits | Lactate: LoB 0.15 mmol/L, LoD 0.19 mmol/L |
| Oxygen Sensitivity (Lactate) | Insensitive to oxygen changes between 20 to >500 mmHg (equivalence demonstrated) | The study demonstrated that the i-STAT Lactate test is insensitive to oxygen changes between 20 to >500 mmHg. |
| Interference | No significant interference (difference between control and test samples within allowed error (Ea)) | |
| (Note: Bromide and Glycolic Acid were identified as interferents for Lactate, with specific effects reported) | pH, PO2, PCO2: No interference found for Acetaminophen, Atracurium, Calcium, Ethanol, Ibuprofen, Morphine, Potassium, Sodium, Bilirubin, Hemoglobin, Triglyceride, Intralipid, Thiopental. | |
| Lactate: No interference for Acetaldehyde, Acetaminophen, N-Acetyl-Cysteine, Ascorbic Acid, β-Hydroxybutyric Acid, Bilirubin, Dopamine, Formaldehyde, Hemoglobin, Hydroxyurea, Pyruvate, Salicylate, Thiocyanate, Triglyceride, Intralipid, Uric Acid. Interference identified for Bromide (decreased results ≥ 40.7 mmol/L) and Glycolic Acid (increased results ≥ 1.18 mmol/L). | ||
| Method Comparison | Acceptable correlation with predicate device (e.g., high r-value, slope near 1, intercept near 0) | pH: N=316, Slope 1.05, Intercept -0.34, r 0.97 |
| PO2: N=308, Slope 1.03, Intercept -3.96, r 0.99 | ||
| PCO2: N=327, Slope 1.01, Intercept -1.29, r 0.99 | ||
| Lactate: N=246, Slope 0.96, Intercept 0.08, r 1.00 |
2. Sample Sizes Used for the Test Set and Data Provenance
- Precision (Aqueous Materials): The "test set" for this was aqueous materials. N values for each level were 80 or 81. Provenance is not explicitly stated beyond "at one site." It's an analytical performance study, not involving human subjects directly.
- Precision (Whole Blood): The "test set" for this involved whole blood venous and arterial specimens. Sample sizes (N) varied by sample type and range for each analyte (e.g., pH venous
§ 862.1120 Blood gases (P
CO2 , PO2 ) and blood pH test system.(a)
Identification. A blood gases (PCO2 , PO2 ) and blood pH test system is a device intended to measure certain gases in blood, serum, plasma or pH of blood, serum, and plasma. Measurements of blood gases (PCO2 , PO2 ) and blood pH are used in the diagnosis and treatment of life-threatening acid-base disturbances.(b)
Classification. Class II.