Haematology Cartridges

About the technology

CE marking

The CG4+ and CHEM8+ cartridges (Abbott) are classified as IVD General in vitro diagnostic medical devices (98/79/EC). The CG4+ cartridge was CE marked in October 2003 and the CHEM8+ cartridge in December 2006.

Description

The i‑STAT is a handheld, in vitro analyser designed to be used at the patient's bedside (point‑of‑care) for testing arterial, venous or capillary whole blood. It takes single‑use cartridges containing chemically sensitive biosensors on a silicon chip that are configured for test‑specific indicators. i‑STAT test cartridges are available for a broad range of diagnostic and treatment indicators including blood gases, electrolytes, metabolites and coagulation markers. Blood samples do not need to be processed before testing and results are available in around 2 minutes.

The i‑STAT system has the following components, accessories and consumables:

• i‑STAT analyser – a handheld, battery‑operated and fully automated analysis platform, consisting of a LCD screen and keypad. Two versions of the i‑STAT analyser are available: a wireless internet version (the i‑STAT Wireless, which can upload the results wirelessly) and a non‑wireless version (with which test results can be uploaded when the analyser is placed in the i‑STAT downloader/recharger).
• i‑STAT cartridges – single‑use, disposable cartridges for whole‑blood testing. They are inserted into the analyser after the blood sample has been applied. A large number of cartridges are available to test the most common test‑specific indicators in different combinations. Cartridges include tests for blood gases, electrolytes, metabolites and coagulation.
• i‑STAT downloader/recharger – acts as a cradle for the analyser, automatically uploading data (with the non‑wireless analyser) and recharging its batteries.
• Electronic simulator – for checking the performance of the i‑STAT analyser.
• TriControls – a set of control solutions at 3 clinically relevant concentrations of test‑specific indicators for verifying each cartridge type.
• i‑STAT data manager – data management software for cartridges, where test records can be transmitted to and then be printed or transmitted to the laboratory/hospital information system.
• i‑STAT printer – an optional portable printer which enables the operator to print results at the point of care.

This briefing report focuses on 2 i‑STAT cartridges, the CG4+ and CHEM8+, which are most relevant to the NHS ED setting.

The CG4+ cartridge provides the following chemistry test and blood gas measures:

• lactate
• pH
• the partial pressure of carbon dioxide (PCO2)
• the partial pressure of oxygen (PO2)
• total carbon dioxide (TCO2; calculated)
• bicarbonate (HCO3; calculated)
• base excess (calculated)
• oxygen saturation (sO2; calculated).

The CHEM8+ cartridge provides the following electrolyte and haematology tests:

• sodium
• potassium
• chloride
• urea nitrogen/urea
• glucose
• creatinine
• ionised calcium
• total carbon dioxide (TCO2)
• anion gap (calculated)
• haematocrit
• haemoglobin (calculated).