THE EFFECT OF PROLONGED TOURNIQUET APPLICATION ON SERUM BICARBONATE

BACKGROUND Many clinicians believe that prolonged tourniquet applicati on lowers the serum bicarbonate concentration in samples drawn from th at limb, but this effect has never been examined prospectively. OBJECT IVE To test the effect of prolonged tourniquet application before phle botomy on serum bicarbonate concentration in healthy adults. METHODS W e drew blood samples from 27 healthy adult volunteers without a tourni quet and again 1, 3, and 5 minutes after applying a blood pressure cuf f and inflating it to the mean arterial pressure. RESULTS The mean bic arbonate concentration was 27.3 +/- 2.26 mmol/L (standard deviation) a t baseline, 27.7 +/- 2.39 mmol/L at 1 minute, 27.7 +/- 2.05 mmol/L at 3 minutes, and 27.7 +/- 1.96 mmol/L at 5 minutes. The mean change in b icarbonate concentration from baseline was -0.04 +/- 1.02 mmol/L at 1 minute, 0.44 +/- 1.05 mmol/L at 3 minutes, and 0.44 +/- 1.31 mmol/L at 5 minutes. The mean lactate concentration was 1.1 +/- 0.28 mmol/L at baseline, 1.3 +/- 0.65 mmol/L at 1 minute, 1.2 +/- 0.52 mmol/L at 3 mi nutes, and 1.2 +/- 0.36 mmol/L at 5 minutes. The mean change in lactat e concentration from baseline was 0.15 +/- 0.67 mmol/L at 1 minute, 0. 11 +/- 0.11 mmol/L at 3 minutes, and 0.12 +/- 0.37 mmol/L at 5 minutes . CONCLUSIONS Prolonged tourniquet application before phlebotomy does not lower the serum bicarbonate concentration in healthy adults.