By Nicholas Borgert

The need to test and quickly diagnose elevated and dangerous levels of bilirubin in newborns was once a function performed almost exclusively by busy lab staff who spend their days operating the large clinical chemistry analyzers in a hospital’s high-volume central laboratory. Now that testing protocol is rapidly changing as hospitals focusing on critical care near patient testing continue to invest in the OMNI S analyzer, the latest extension of the OMNI blood gas analyzer line developed and marketed by Roche Diagnostics.

High levels of bilirubin are an indication that an infant’s system is not functioning properly. Elevated bilirubin often means the baby’s body is destroying an excessive number of red blood cells or that his or her liver is not removing enough bilirubin from the blood supply. Though jaundice, the yellowing of skin and the whites of the eyes, is one common indicator that bilirubin accumulation in the blood is dangerously high, testing and monitoring are necessary for physicians and caregivers to determine an exact cause and plan treatment. Excessive bilirubin levels often signal metabolic problems, obstructions within the bile duct, a cirrhosis in the liver resulting from physical or chemical damage, or an inherited condition.

For older children and adults, elevated bilirubin doesn’t carry the same risk as it does for newborns. For infants up to 4 weeks old, high bilirubin levels can be toxic to brain development, leading to retardation, physical abnormalities, and blindness. Neonatal bilirubin is not uncommon during the first 3 days of an infant’s life when a newborn’s system lacks the ability to produce enough intestinal bacteria to process bilirubin. In fact, as many as half of full-term newborns show elevated bilirubin levels. Preterm babies are particularly vulnerable to the condition.

In healthy infant bodies, high bilirubin levels disappear within a few days. If high levels continue, special treatments and regular testing are used. Treatments frequently range from photo therapy to transfusions.

Bedside Bilirubin Testing
For the past year and a half, Roche has been bringing important tests for bilirubin closer to the tiny patients who need them most. The company’s newest OMNI S analyzer was designed at the Roche Center for Excellence in Switzerland to function as a workhorse blood gas analyzer in both point-of-care settings (such as neonatal intensive care units and emergency rooms) and hospital central laboratories.

In fact, bilirubin is just one of 18 important critical care parameters available on the OMNI S analyzer. The fully automated analyzer is also configured to produce measurements through tests for pH, P02, PC02, sodium, potassium, ionized calcium, chloride, hematocrit, glucose, lactate, urea/BUN, total hemoglobin, oxygen saturation, oxyhemoglobin, deoxyhemoglobin, carboxyhemoglobin, and methemoglobin. The analyzer handles samples of whole blood, serum, plasma, and aqueous solutions.

According to Mike Kolodkin, product manager for Blood Gas and ISE Systems at Roche Diagnostics, the OMNI advanced open system architecture and sensor-based technology can produce the 18 critical care parameters in less than 100 seconds. Results from the bilirubin test, available on any OMNI S analyzer with C0-OX, are produced in just 60 seconds, Kolodkin says.

A Respected Pedigree
Roche launched its line of easy-use, automated OMNI blood gas analyzers in 1996. The product line has grown to become one of the most popular analyzers in clinics, labs, and hospitals. Kolodkin says the newly configured OMNI S analyzer for bilirubin and other critical care tests was unveiled 19 months ago for the European market. Roche premiered the analyzer at the 2003 Philadelphia session of the American Association for Clinical Chemistry. Following formal 510(k) approval from the Food and Drug Administration, the OMNI S began distribution for the US market during the fourth quarter of 2003.

“The OMNI S in its various configurations has received a positive reception in the marketplace from the very beginning,” Kolodkin says. “That’s not surprising since our OMNI platform has been getting a great deal of acceptance for nearly a decade.”

The OMNI S offers a number of features that distinguish it from other brands of blood gas analyzers and platforms and make it an ideal choice for critical care near-patient testing, according to Kolodkin. “We made the OMNI S flexible as well as extremely user-friendly,” he says.

The OMNI S requires a whole blood sample of less than 80 µL for a complete picture of a patient’s oxygenation status (pH, PO2, PCO2, tHb, SO2). The analyzer’s bilirubin test requires only about 88 µL of whole blood (about three drops) and generates results in a minute or so.

Roche offers the OMNI S in four different instrument configurations geared to the different needs of critical care settings (OMNI S 1-4). In addition to neonatal units, the analyzer performs effectively in intensive care units, emergency rooms, operating rooms, remote and STAT-labs, recovery rooms, and renal dialysis centers.

“That small sample is important in minimizing invasiveness on a newborn,” Kolodkin says. “The OMNI S’s neonate test system is fully automated, uncomplicated and not time-consuming.”

According to Kolodkin, rapid response and near-patient testing were key forces that drove development of the OMNI S analyzer models. He also points to three technical features that make the analyzer an attractive addition for hospitals and laboratories.

“The OMNI S is the first analyzer to provide liquid calibration without requiring the use of external [and potentially hazardous] external gas tanks,” he says. The design includes maintenance-free sensors with a typical life of 12 months or more.

Another advantage involves reagents. The OMNI S features a transponder-managed smart reagent pack that operates in real time and frees a user from having to enter a bar code or punch keys. The operator can move the transponder and reintroduce the reagent pack without compromising the test, Kolodkin says.

“Users don’t have to worry about running out of reagents, when the lab supply person is not available during a hospital central lab’s off-hours,” he says. “The user doesn’t have to do anything. The transponder continues gathering test data when it’s plugged into another analyzer.”

“We understand that a limited laboratory staff can get stretched thin by ever-increasing volumes of testing,” Kolodkin says. “At Roche, we manufacture our analyzers to be extremely operationally efficient.”

In many cases, the analyzer’s reagent supply needs replacement only once or twice per month. By using an empty S1 bottle as a waste bottle, users can extend running time and cut costs even more.

Quality control is another primary benefit of the OMNI S platform, according to Kolodkin. Roche offers the OMNI S analyzer with an optional AutoQC module capable of storing up to 40 days of QC onboard and providing simultaneous comparisons lot to lot that fully meet applicable regulatory requirements. The analyzer comes standard with RS232 and Ethernet interfaces; its protocol permits direct connection of the OMNI S to DataCarePOC and OMNILINK, Roche supported data and instrument management IT solutions.

Kolodkin says a 2-minute online demonstration of the OMNI S analyzer available on the Roche Web site has become a popular source of information and review for interested hospitals and lab professionals.

“When you look at the instrument’s service and capabilities over a 5-year period, the OMNI S is parallel with the market,” he says.

In the near future, Roche Diagnostics will introduce an OMNI S 5 to handle glucose and lactate parameters, and an OMNI S 6 designed for glucose, lactate, and BUN/urea measurements.

Nicholas Borgert is a contributing writer for Clinical Lab Products.