ABSTRACT
Puncture of the radial or cubital artery with a thin needle of 0.4--0.5 mm diameter connected to a glass capillary is a simple and non-invasive technique for obtaining samples for arterial blood gas analysis. Compared with the conventional sampling techniques using glass syringes and needles of larger calibers, the results, especially with regard to paO2 values, show very close agreement over a wide range from hypoxic to hyperoxic conditions (correlation coefficient r2 = 0.99) if the microsamples are analysed within 10 minutes. Delayed analysis after 30 minutes, however, shows marked underestimation of hyperoxic paO2 (greater than 150 mm Hg) with the microtechnique, whereas paO2 values below 100 mm Hg are still comparable to the macrosamples. The method described provides an accurate arterial blood gas analysis without discomfort or harmful side effects, especially in patients under treatment with anticoagulants.
