All patients receive the three types of blood test (venous blood test, skin puncture blood (capillary blood) test and arterial blood gas analysis

Point of care blood analysis obtained from skin puncture

Primary outcome

1. Correlation of blood concentration between skin puncture blood and venous blood

   • variables Na+ (mmol/L) K+ (mmol/L) Ca++ (mmol/L) Hct (%) Glucose (mg/dl) Creatinine (mg/dl) Cl- (mmol/L)

2. Correlation of blood concentration between skin puncture blood and arterial blood

   • variables pH pCO2 (mmHg) pO2 (mmHg) HCO3 (mmol/L) Lactate (mmol/L)

Spearman correlation rank test will be performed to show the agreement of two methods in each value.

We will show the correlation coefficient for all values. Ex) The correlation coefficient of Na+, K+, Ca2+, Hct, glucose, creatinine and Cl- are ___, ___, ___, ___, ___, ___, ___, respectively.