Use of finer needles for venipuncture increases in vitro haemolysis despite reducing persistent pain and nerve injury: A retrospective study.

BACKGROUND: Although venipuncture is minimally invasive, and is the most frequently performed medical procedure, it carries the small risk of causing persistent pain, including nerve damage. Recently, our hospital stopped using 22-gauge needles for venipuncture in outpatients and switched to using only 23- and 25-gauge needles. We investigated the impact of using only the finer needles on the incidence of persistent or neuropathic pain and the prevalence of haemolysis, as well as the impact of haemolysis associated with the needle change on other laboratory data. METHODS: We retrospectively collected and analysed data on venipuncture-associated pain complaints made during the 1-year period prior and 1-year period after the change in needles, as well as the frequency of haemolysis before and after the change. We also focused on 90 cases that showed significant haemolysis after the needle change and compared the serum aspartate aminotransferase, lactate dehydrogenase, and potassium levels before and after the needle change. RESULTS: The incidence of persistent pain was significantly reduced from 1 in 10,825 venipunctures before the change to 1 in 29,747 venipunctures after the change. Notably, no patients experienced neuropathic pain after the change. However, the prevalence of haemolysis was significantly increased. Additionally, the serum aspartate aminotransferase, lactate dehydrogenase, and potassium levels were significantly elevated in the cases that showed moderate to gross haemolysis after the needle change. CONCLUSION: Using finer needles involves both advantages and disadvantages, and careful consideration is needed to determine which type of needle is in the best interests of the patient.

Endothelial dysfunction precedes atherosclerotic lesions and platelet activation in high fat diet-induced prothrombotic state.

INTRODUCTION: Earlier we have demonstrated a prothrombotic state in spontaneously atherogenic rodents kept on Western-style high fat diet. The aim of the present study was to investigate the cellular mechanism of such prothrombotic state. MATERIALS AND METHODS: Two kinds of diets, Western-style high fat diet containing 20% fat (w/w) and 0.05% cholesterol (w/w) and low fat diet containing 7% fat without cholesterol based on AIN93G, were added to diet-sensitive apolipoprotein E and low-density lipoprotein receptor double deficient male mice for 12 or 18 weeks from 6 weeks of age. Atherosclerosis was assessed by morphometry of the aortic wall or lipid-stained lesions. Endothelial function was measured by flow-mediated vasodilation (FMV) of the femoral artery. Platelet reactivity was measured ex vivo by a shear-induced platelet aggregation test. RESULTS AND CONCLUSIONS: 12 weeks feeding of mice with high fat diet significantly impaired FMV, as compared with mice fed with low fat diet (P<0.05). In contrast, there was no significant difference in the lipid-stained areas and in the reactivity of platelets between the two groups. 18 weeks feeding with high fat diet significantly impaired FMV (P<0.05) and enhanced both lipid-stained areas (P<0.05) and platelet reactivity (P<0.01). These findings show that in high fat diet-induced prothrombotic state, endothelial dysfunction precedes both the morphologically detectable lesions and the enhancement of platelet reactivity.

Impaired spontaneous thrombolytic activity in elderly and in habitual smokers, as measured by a new global thrombosis test.

We used a new test (the Görög Thrombosis Test) for assessing the effect of aging, smoking and exercise habits on the overall thrombotic status including platelet reactivity and spontaneous thrombolytic activity of 30 healthy young males (mean, 21.1 +/- 0.4 years) and 34 elderly males (64.5 +/- 1.1 years). The occlusion time (OT) and the lysis time (LT) were measured from a single native blood sample. The OT is an index of platelet activation and subsequent occlusive thrombus formation by high shear stress, while the LT is an index of the resumption of blood flow due to thrombolysis. The LTs in the elderly group were significantly longer than in the young group (P < 0.001). The LTs of elderly smokers were significantly longer than those of non-smokers (P < 0.001). Exercise did not affect the LT significantly. Platelet reactivity to shear stress (OT) was not affected either by aging, smoking or exercise habits. Suppressed spontaneous thrombolytic activity in elderly males and smokers could be a mechanism of acute thrombotic events in these people.