OBJECTIVE: To evaluate the accuracy of potassium concentrations measured by blood gas analysis (PBG) compared with laboratory serum potassium (LSP), in the initial care of patients with diabetic ketoacidosis (DKA). SUBJECTS AND METHODS: Fifty three patients with diabetes mellitus were evaluated in a retrospective analysis. PBG was carried out using the Radiometer ABL 700 (Radiometer Copenhagen®), and results were compared with LSP ADVIA 1650 Chemistry system (Siemens®), the gold standard method. Both methods are based on potentiometry. RESULTS: Mean PBG was 3.66 mmol/L and mean LSP was 4.79 mmol/L. Mean difference between PBG and LSP was -1.13 mmol/L (p < 0.0005, 95% CI, -1.39 to -0,86). Lin concordance correlation coefficient was rc = 0.28 (95% CIb, 0.10 to 0.45), demonstrating low concordance between the methods. CONCLUSION: Although PBG measurement is faster and easier, it should not be used as a surrogate for LSP in the clinical treatment of DKA.

RESUMOO trabalho visa avaliar eficácia e a preferência dos pacientes na monitorização da glicemia capilar em locais alternativos: lóbulo de orelha, antebraço e panturrilha em relação à ponta de dedo. Foram avaliados 89 pacientes (39 M/50 F) com diabetes melito tipo 2 (DM2). A monitorização foi feita com glicosímetro digital (ACCU -CHEK Performa, Roche), lancetador ACCU-CHEK Multiclix, em grau 5 na face palmar da falange distal do 3 o dedo da mão direita, porção inferior do lóbulo da orelha direita, antebraço direito e região superior da panturrilha direita. Não houve diferença da glicemia capilar na ponta de dedo em relação aos locais alternativos. A ponta de dedo foi o local mais doloroso. Quanto ao local de preferência, a orelha e a ponta de dedo foram os preferidos. A monitorização glicêmica em locais alternativos é simples, segura e eficaz, como a glicemia de ponta de dedo. Arq Bras Endocrinol Metab. 2009;53(3):344-7.Descritores Glicemia capilar; locais alternativos; diabetes melito; monitorização glicêmica ABSTRACT This paper evaluate the efficacy and patients preferences of glucose monitoring in alternatives sites: ear lobe, forearm and calf against conventional fingerstick. We studied 89 patients (39 M/ 50 F) with type 2 diabetes mellitus (DM2). Glucose monitoring was measured using a digital glucosimeter (ACCU -CHEK Performa, Roche), and ACCU-CHEK Multiclix lancetador, with grade 5 on the distal phalange on the right hand's third finger, inferior part of right ear lobe, right forearm and right calf. There was not statistical significance on the comparative analyzes of fingerstick and alternatives sites. There was more pain in fingerstick. The patients preferred the fingerstick and the ear lobe. Glucose monitoring in alternative sites is as simple, safe and efficient as fingerstick. Arq Bras Endocrinol Metab. 2009;53(3):344-7.