ABG Analyzers

ABG Analyzers Directly measures [blank_start]PCO2[blank_end] - Severinghaus, [blank_start]PO2[blank_end] - Clark, pH - [blank_start]Sanz[blank_end] HCO3, SaO2 and other values are calculated Formula for read out: (Barometric Pressure - [blank_start]47[blank_end]) x Fractional Concentration of [blank_start]gas[blank_end]

Severinhaus Electrode Measures [blank_start]PCO2[blank_end] [blank_start]Glass[blank_end] electrode in [blank_start]lucite[blank_end] jacket Includes nylon spacer and [blank_start]teflon[blank_end] membrane

PCO2 Calibration: Cylinders containing known concentrations of gas: Low: [blank_start]5[blank_end]% balance High: [blank_start]10[blank_end]% slope

Clark Electrode Measures [blank_start]PO2[blank_end] Platinum cathode, silver-silver chloride anode, polypropolene membrane (gas [blank_start]permeable[blank_end]) Using [blank_start]mylar[blank_end] membrane results in insufficient O2 diffusion Cleaning top with [blank_start]pumice[blank_end] periodically to clean [blank_start]protein[blank_end]

PO2 Calibration: Cylinders containing known concentrations of gas: Low: [blank_start]0[blank_end]% balance High: [blank_start]12[blank_end]% or [blank_start]20[blank_end]% slope

Sanz Electrode Measures PH Reference Electrode Contains: [blank_start]KCL[blank_end] solution with known PH, has contsant [blank_start]electrical[blank_end] potential. Measuring electrode contains: [blank_start]Buffer[blank_end] Solution, silver-silver chloride wire and pH sensitive glass capillary tube Introduction of sample causes electrical [blank_start]potential[blank_end] to develop. Voltage difference is proportional to PH [blank_start]difference[blank_end]

Sanz Electrode Calibration: Low pH solution: [blank_start]6.84[blank_end] - If displayed value is different than the known sample, adjust with the [blank_start]balance[blank_end] to known value. High pH solution: [blank_start]7.384[blank_end] - If displayed value is different than the known sample, adjust with the [blank_start]slope[blank_end] control to known value.

Tonomotry Used for quality [blank_start]control[blank_end] with ABG analyzers Allows precise gas mixtures to be [blank_start]equilibrated[blank_end] with buffer solution or whole blood samples Best method for precise control of [blank_start]Clark[blank_end] electrode Vert complex - not widely used