PMC:28992 / 2746-8521 JSONTXT

{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/28992","sourcedb":"PMC","sourceid":"28992","source_url":"http://www.ncbi.nlm.nih.gov/pmc/28992","text":"Methods\nThe emergency system at the University of Graz is a combination of stationary and rendezvous components. The stationary component is an emergency patient transport vehicle, operated by four emergency technicians of the Austrian Red Cross. One of these individuals, similar to American paramedics, is a young physician or medical student, at the end of their training, who specialised in emergency medicine. The second component is a small emergency car, carrying the emergency physician and an emergency technician, which transports the doctor to the site of the accident, but which cannot transport the patient. Consequently, six well educated emergency staff members attend the patient at the site of the accident.\nFirstly, six indications for prehospital blood analysis were defined:\n1. cardiopulmonary resuscitation (CPR; blood gases and electrolytes);\n2. all forms of dyspnea or hypoxia (blood gases);\n3. suspected acidosis (blood gases and electrolytes);\n4. cardiogenic shock resistant to therapy (blood gases and electrolytes);\n5. control of mechanical ventilation (blood gases), and\n6. cardiac arrhythmias and tachycardia (electrolytes).\nThe device was carried in the rendezvous car to the site of the emergency. Samples for tests which included blood gas analysis were taken from an artery with a 26G needle and a heparinized syringe; samples for electrolytes alone were taken from an artery or vein. Additionally, a form was completed by the emergency physician which included the following two questions:\n1. Was knowledge of the measured parameters helpful to your diagnosis or treatment?\n2. Did you change your therapy due to the prehospital tests?\nThe emergency physician obtained and interpreted the measurements, and performed the resulting therapeutic interventions at the site of the emergency. All emergency doctors were anesthesiologists at the Department of Anesthesiology and Critical Care Medicine with more than 2 years' experience in prehospital care.\nAll data were recorded and evaluated after completion of the study. A retrospective investigation of the outcome of the patients and the accuracy of the tentative diagnosis was not performed. The study aimed to evaluate the management and usefulness of a new transportable blood analyzer at the site of an emergency, and the immediate therapeutic consequences.\nA prerequisite of the study was not to disturb the essential treatment of emergency patients. The study was approved by the ethics review board of the University.\n\nTechnical description\nThe IRMA Blood Analysis System is one of a new class of instruments which are used for what is termed `point-of-care testing' (POCT) [2], indicating that it can be used wherever the patient may be to measure blood gases and pH, as well as the electrolytes sodium (Na), K and Ca2+.\nThe device consists of the analyzer and two types of cartridge, one labeled `blood gases' and the other `electrolytes'. Each cartridge is prepackaged with a calibration gel covering the sensors, and with a short fluid filled pouch which stabilizes the humidity. The calibration of the sensors takes place automatically when the cartridge is inserted into the IRMA blood analyzer; there is no need for calibration gases or fluids. Quality control calibration is performed with delivered control reagents. The instrument can only be filled using a syringe, and the blood sample (minimum = 0.2 ml, maximum = 3.0 ml, recommended amount = 1.5 ml) must be injected with dosed power into the filling gap of the cartridge. The instrument measures barometric pressure and determines pH, pO2, and pCO2 by analyzing the sample in the blood gas analysis (BGA) cartridge; additional parameters are also calculated (see Table 1). Using the electrolyte cartridge, Na, K and Ca2+ are determined. The accuracy of the measurements from the IRMA blood analyzer have been validated in previous studies [2,3]. The device has the size (29.2 × 24.1 × 12.7 cm) and weight (1.35 kg) of a small laptop computer, and each cartridge weighs 19 g and is 9.9 × 5.6 × 1.3 cm in size. The exchangeable batteries operate for 2–3 h and are recharged by an external charger.\nData entry into the analyzer is performed through a back-lit interactive touch screen. The menus guide the user through the operation process with directly labeled buttons. An on-board printer provides a hard copy of results either automatically or on demand. An RS232 port on the back of the unit allows the downloading of data to a personal computer or other data collection system.\nThe price of the IRMA Blood Analysis System is approximately ATS100,000 ($10,000). Each cartridge (used for one measurement, blood gases or electrolytes) costs about ATS100 ($10). The single-use disposable cartridges can be stored for 12 weeks in normal ambient temperature (12–30°C). The device is Food and Drug Administration (FDA) approved.\nThe system is maintained in stand-by mode, with the power automatically switching on when a cartridge is inserted. The calibration code must be observed and if necessary corrected. After confirmation of this code on the touch screen, the calibration procedure starts automatically. Depending on whether an electrolyte or blood gas cartridge is being used the system requires 10 or 90 s to warm up, respectively. The end of the calibration procedure is announced by a beep, after which the user has 120 s to inject the blood sample. Finally, the results are shown on the display and can be printed on demand. The entire measurement takes approximately 70 s for electrolytes and 160 s for blood gases. Correction of the calibration code, if necessary, requires an additional 25 s.\nIn cases of hypothermia, the blood temperature can be corrected after the measurement and the results recalculated.\n","divisions":[{"label":"Title","span":{"begin":0,"end":7}},{"label":"Section","span":{"begin":2509,"end":5774}},{"label":"Title","span":{"begin":2509,"end":2530}}],"tracks":[]}