BACKGROUND:Ultrasound guidance is commonly used for accessing difficult peripheral veins.For successful access,a tourniquet is required for venodilation.Tourniquets decrease the compressibility and increase the diameter of veins;they also obfuscate artery-vein differentiation on ultrasound.We aimed to establish the upper limit of sphygmomanometer cuff pressure that facilitates artery-vein differentiation during ultrasound-guided peripheral intravenous access. METHODS:We employed the sphygmomanometer cuff as a tourniquet for venodilation and tested it on seven participants at six different levels as follows:0 mmHg,DBP/2,DBP,(DBP+SBP)/2,SBP,and SBP+20 mmHg.We used an ultrasound probe attached to a pressure-measuring instrument to record cross-sectional images of the cubital artery and vein.During ultrasonography,compression was applied to the blood vessels through the skin.The following day,we measured the wrist pulse pressure and observed the oximeter pulse wave at six different tourniquet pressure levels.Repeated-measures analysis of variance(ANOVA)on ranks and Tukey's post-hoc analysis were used for multiple comparisons. RESULTS:Arterial pulsation was maintained at tourniquet pressures between 0 mmHg and(DBP+SBP)/2.However,arterial pulsation decreased or disappeared when the tourniquet pressure reached or exceeded the SBP.Moreover,at this pressure level,the superior compressibility of veins compared to that of arteries was no longer observed.Compression of the artery to 75%and 50%of its original diameter increased arterial pulsation. CONCLUSION:Arterial pulsation and the superior compressibility are useful indicators for differentiating veins from arteries until the tourniquet pressure reaches(DBP+SBP)/2.However,these indicators are not reliable once the tourniquet pressure exceeds the SBP.

BACKGROUND:Ultrasound guidance is commonly used for accessing difficult peripheral veins.For successful access,a tourniquet is required for venodilation.Tourniquets decrease the compressibility and increase the diameter of veins;they also obfuscate artery-vein differentiation on ultrasound.We aimed to establish the upper limit of sphygmomanometer cuff pressure that facilitates artery-vein differentiation during ultrasound-guided peripheral intravenous access. METHODS:We employed the sphygmomanometer cuff as a tourniquet for venodilation and tested it on seven participants at six different levels as follows:0 mmHg,DBP/2,DBP,(DBP+SBP)/2,SBP,and SBP+20 mmHg.We used an ultrasound probe attached to a pressure-measuring instrument to record cross-sectional images of the cubital artery and vein.During ultrasonography,compression was applied to the blood vessels through the skin.The following day,we measured the wrist pulse pressure and observed the oximeter pulse wave at six different tourniquet pressure levels.Repeated-measures analysis of variance(ANOVA)on ranks and Tukey's post-hoc analysis were used for multiple comparisons. RESULTS:Arterial pulsation was maintained at tourniquet pressures between 0 mmHg and(DBP+SBP)/2.However,arterial pulsation decreased or disappeared when the tourniquet pressure reached or exceeded the SBP.Moreover,at this pressure level,the superior compressibility of veins compared to that of arteries was no longer observed.Compression of the artery to 75%and 50%of its original diameter increased arterial pulsation. CONCLUSION:Arterial pulsation and the superior compressibility are useful indicators for differentiating veins from arteries until the tourniquet pressure reaches(DBP+SBP)/2.However,these indicators are not reliable once the tourniquet pressure exceeds the SBP.

BACKGROUND:Ultrasound guidance is commonly used for accessing difficult peripheral veins.For successful access,a tourniquet is required for venodilation.Tourniquets decrease the compressibility and increase the diameter of veins;they also obfuscate artery-vein differentiation on ultrasound.We aimed to establish the upper limit of sphygmomanometer cuff pressure that facilitates artery-vein differentiation during ultrasound-guided peripheral intravenous access. METHODS:We employed the sphygmomanometer cuff as a tourniquet for venodilation and tested it on seven participants at six different levels as follows:0 mmHg,DBP/2,DBP,(DBP+SBP)/2,SBP,and SBP+20 mmHg.We used an ultrasound probe attached to a pressure-measuring instrument to record cross-sectional images of the cubital artery and vein.During ultrasonography,compression was applied to the blood vessels through the skin.The following day,we measured the wrist pulse pressure and observed the oximeter pulse wave at six different tourniquet pressure levels.Repeated-measures analysis of variance(ANOVA)on ranks and Tukey's post-hoc analysis were used for multiple comparisons. RESULTS:Arterial pulsation was maintained at tourniquet pressures between 0 mmHg and(DBP+SBP)/2.However,arterial pulsation decreased or disappeared when the tourniquet pressure reached or exceeded the SBP.Moreover,at this pressure level,the superior compressibility of veins compared to that of arteries was no longer observed.Compression of the artery to 75%and 50%of its original diameter increased arterial pulsation. CONCLUSION:Arterial pulsation and the superior compressibility are useful indicators for differentiating veins from arteries until the tourniquet pressure reaches(DBP+SBP)/2.However,these indicators are not reliable once the tourniquet pressure exceeds the SBP.

BACKGROUND:Ultrasound guidance is commonly used for accessing difficult peripheral veins.For successful access,a tourniquet is required for venodilation.Tourniquets decrease the compressibility and increase the diameter of veins;they also obfuscate artery-vein differentiation on ultrasound.We aimed to establish the upper limit of sphygmomanometer cuff pressure that facilitates artery-vein differentiation during ultrasound-guided peripheral intravenous access. METHODS:We employed the sphygmomanometer cuff as a tourniquet for venodilation and tested it on seven participants at six different levels as follows:0 mmHg,DBP/2,DBP,(DBP+SBP)/2,SBP,and SBP+20 mmHg.We used an ultrasound probe attached to a pressure-measuring instrument to record cross-sectional images of the cubital artery and vein.During ultrasonography,compression was applied to the blood vessels through the skin.The following day,we measured the wrist pulse pressure and observed the oximeter pulse wave at six different tourniquet pressure levels.Repeated-measures analysis of variance(ANOVA)on ranks and Tukey's post-hoc analysis were used for multiple comparisons. RESULTS:Arterial pulsation was maintained at tourniquet pressures between 0 mmHg and(DBP+SBP)/2.However,arterial pulsation decreased or disappeared when the tourniquet pressure reached or exceeded the SBP.Moreover,at this pressure level,the superior compressibility of veins compared to that of arteries was no longer observed.Compression of the artery to 75%and 50%of its original diameter increased arterial pulsation. CONCLUSION:Arterial pulsation and the superior compressibility are useful indicators for differentiating veins from arteries until the tourniquet pressure reaches(DBP+SBP)/2.However,these indicators are not reliable once the tourniquet pressure exceeds the SBP.

BACKGROUND:Ultrasound guidance is commonly used for accessing difficult peripheral veins.For successful access,a tourniquet is required for venodilation.Tourniquets decrease the compressibility and increase the diameter of veins;they also obfuscate artery-vein differentiation on ultrasound.We aimed to establish the upper limit of sphygmomanometer cuff pressure that facilitates artery-vein differentiation during ultrasound-guided peripheral intravenous access. METHODS:We employed the sphygmomanometer cuff as a tourniquet for venodilation and tested it on seven participants at six different levels as follows:0 mmHg,DBP/2,DBP,(DBP+SBP)/2,SBP,and SBP+20 mmHg.We used an ultrasound probe attached to a pressure-measuring instrument to record cross-sectional images of the cubital artery and vein.During ultrasonography,compression was applied to the blood vessels through the skin.The following day,we measured the wrist pulse pressure and observed the oximeter pulse wave at six different tourniquet pressure levels.Repeated-measures analysis of variance(ANOVA)on ranks and Tukey's post-hoc analysis were used for multiple comparisons. RESULTS:Arterial pulsation was maintained at tourniquet pressures between 0 mmHg and(DBP+SBP)/2.However,arterial pulsation decreased or disappeared when the tourniquet pressure reached or exceeded the SBP.Moreover,at this pressure level,the superior compressibility of veins compared to that of arteries was no longer observed.Compression of the artery to 75%and 50%of its original diameter increased arterial pulsation. CONCLUSION:Arterial pulsation and the superior compressibility are useful indicators for differentiating veins from arteries until the tourniquet pressure reaches(DBP+SBP)/2.However,these indicators are not reliable once the tourniquet pressure exceeds the SBP.

BACKGROUND:Ultrasound guidance is commonly used for accessing difficult peripheral veins.For successful access,a tourniquet is required for venodilation.Tourniquets decrease the compressibility and increase the diameter of veins;they also obfuscate artery-vein differentiation on ultrasound.We aimed to establish the upper limit of sphygmomanometer cuff pressure that facilitates artery-vein differentiation during ultrasound-guided peripheral intravenous access. METHODS:We employed the sphygmomanometer cuff as a tourniquet for venodilation and tested it on seven participants at six different levels as follows:0 mmHg,DBP/2,DBP,(DBP+SBP)/2,SBP,and SBP+20 mmHg.We used an ultrasound probe attached to a pressure-measuring instrument to record cross-sectional images of the cubital artery and vein.During ultrasonography,compression was applied to the blood vessels through the skin.The following day,we measured the wrist pulse pressure and observed the oximeter pulse wave at six different tourniquet pressure levels.Repeated-measures analysis of variance(ANOVA)on ranks and Tukey's post-hoc analysis were used for multiple comparisons. RESULTS:Arterial pulsation was maintained at tourniquet pressures between 0 mmHg and(DBP+SBP)/2.However,arterial pulsation decreased or disappeared when the tourniquet pressure reached or exceeded the SBP.Moreover,at this pressure level,the superior compressibility of veins compared to that of arteries was no longer observed.Compression of the artery to 75%and 50%of its original diameter increased arterial pulsation. CONCLUSION:Arterial pulsation and the superior compressibility are useful indicators for differentiating veins from arteries until the tourniquet pressure reaches(DBP+SBP)/2.However,these indicators are not reliable once the tourniquet pressure exceeds the SBP.

BACKGROUND:Ultrasound guidance is commonly used for accessing difficult peripheral veins.For successful access,a tourniquet is required for venodilation.Tourniquets decrease the compressibility and increase the diameter of veins;they also obfuscate artery-vein differentiation on ultrasound.We aimed to establish the upper limit of sphygmomanometer cuff pressure that facilitates artery-vein differentiation during ultrasound-guided peripheral intravenous access. METHODS:We employed the sphygmomanometer cuff as a tourniquet for venodilation and tested it on seven participants at six different levels as follows:0 mmHg,DBP/2,DBP,(DBP+SBP)/2,SBP,and SBP+20 mmHg.We used an ultrasound probe attached to a pressure-measuring instrument to record cross-sectional images of the cubital artery and vein.During ultrasonography,compression was applied to the blood vessels through the skin.The following day,we measured the wrist pulse pressure and observed the oximeter pulse wave at six different tourniquet pressure levels.Repeated-measures analysis of variance(ANOVA)on ranks and Tukey's post-hoc analysis were used for multiple comparisons. RESULTS:Arterial pulsation was maintained at tourniquet pressures between 0 mmHg and(DBP+SBP)/2.However,arterial pulsation decreased or disappeared when the tourniquet pressure reached or exceeded the SBP.Moreover,at this pressure level,the superior compressibility of veins compared to that of arteries was no longer observed.Compression of the artery to 75%and 50%of its original diameter increased arterial pulsation. CONCLUSION:Arterial pulsation and the superior compressibility are useful indicators for differentiating veins from arteries until the tourniquet pressure reaches(DBP+SBP)/2.However,these indicators are not reliable once the tourniquet pressure exceeds the SBP.

BACKGROUND:Ultrasound guidance is commonly used for accessing difficult peripheral veins.For successful access,a tourniquet is required for venodilation.Tourniquets decrease the compressibility and increase the diameter of veins;they also obfuscate artery-vein differentiation on ultrasound.We aimed to establish the upper limit of sphygmomanometer cuff pressure that facilitates artery-vein differentiation during ultrasound-guided peripheral intravenous access. METHODS:We employed the sphygmomanometer cuff as a tourniquet for venodilation and tested it on seven participants at six different levels as follows:0 mmHg,DBP/2,DBP,(DBP+SBP)/2,SBP,and SBP+20 mmHg.We used an ultrasound probe attached to a pressure-measuring instrument to record cross-sectional images of the cubital artery and vein.During ultrasonography,compression was applied to the blood vessels through the skin.The following day,we measured the wrist pulse pressure and observed the oximeter pulse wave at six different tourniquet pressure levels.Repeated-measures analysis of variance(ANOVA)on ranks and Tukey's post-hoc analysis were used for multiple comparisons. RESULTS:Arterial pulsation was maintained at tourniquet pressures between 0 mmHg and(DBP+SBP)/2.However,arterial pulsation decreased or disappeared when the tourniquet pressure reached or exceeded the SBP.Moreover,at this pressure level,the superior compressibility of veins compared to that of arteries was no longer observed.Compression of the artery to 75%and 50%of its original diameter increased arterial pulsation. CONCLUSION:Arterial pulsation and the superior compressibility are useful indicators for differentiating veins from arteries until the tourniquet pressure reaches(DBP+SBP)/2.However,these indicators are not reliable once the tourniquet pressure exceeds the SBP.

Introduction: Voriconazole (VRCZ) is a triazole antifungal agent for which therapeutic drug monitoring (TDM) is recommended. At Juntendo University Hospital, the VRCZ TDM implementation rate was 42% between January 2011 and October 2017. Here, we report that modifications to the hospital’s drug ordering system improved the implementation rate of VRCZ TDM.Method: In August 2018, the drug ordering system was modified so that a message appeared on the screen to notify clinicians of the need to monitor VRCZ blood concentrations and to recommend a date for sample collection. In addition, the laboratory orders for VRCZ levels were digitized. We compared two one-year periods before and after implementation of the modifications (August 2017 to July 2018 and August 2018 to July 2019) to verify the effect of the changes.Result: Results showed an increase in the TDM implementation rate: 12 patients (42.8%) received TDM before modification of the system, and 26 patients (92.9%) received TDM after modification of the system. Further, the rate of blood sampling at the recommended time point for estimating blood concentration (day 5-7 after the start of administration) improved after system modification, i.e., blood samples were collected from 18 patients (64.3%) at the steady state point. In contrast, blood samples were collected from only 6 patients (21.4%) before system modification. When blood concentrations deviated from the target range in patients who received TDM, clinicians took appropriate actions, such as reducing drug doses, prescribing drug holidays, or discontinuing medications.Conclusion: A system that provides information related to VRCZ blood concentration measurements can help clinicians provide patients with optimal pharmacotherapy.