BACKGROUND: More than 140 million people drink arsenic-contaminated groundwater. It is unknown how much arsenic exposure is necessary to cause neurological impairment. Here, we evaluate the relationship between neurological impairments and the arsenic concentration in drinking water (ACDW). PARTICIPANTS AND METHODS: A cross-sectional study design was employed. We performed medical examinations of 1867 residents in seven villages in the Thabaung township in Myanmar. Medical examinations consisted of interviews regarding subjective neurological symptoms and objective neurological examinations of sensory disturbances. For subjective neurological symptoms, we ascertained the presence or absence of defects in smell, vision, taste, and hearing; the feeling of weakness; and chronic numbness or pain. For objective sensory disturbances, we examined defects in pain sensation, vibration sensation, and two-point discrimination. We analyzed the relationship between the subjective symptoms, objective sensory disturbances, and ACDW. RESULTS: Residents with ACDW ≥ 10 parts per billion (ppb) had experienced a "feeling of weakness" and "chronic numbness or pain" significantly more often than those with ACDW < 10 ppb. Residents with ACDW ≥ 50 ppb had three types of sensory disturbances significantly more often than those with ACDW < 50 ppb. In children, there was no significant association between symptoms or signs and ACDW. CONCLUSION Subjective symptoms, probably due to peripheral neuropathy, occurred at very low ACDW (around 10 ppb). Objective peripheral nerve disturbances of both small and large fibers occurred at low ACDW (> 50 ppb). These data suggest a threshold for the occurrence of peripheral neuropathy due to arsenic exposure, and indicate that the arsenic concentration in drinking water should be less than 10 ppb to ensure human health.
Adolescent ; Adult ; Arsenic ; analysis ; toxicity ; Cross-Sectional Studies ; Dietary Exposure ; adverse effects ; Dose-Response Relationship, Drug ; Drinking Water ; adverse effects ; chemistry ; Female ; Groundwater ; chemistry ; Humans ; Male ; Middle Aged ; Myanmar ; epidemiology ; Peripheral Nervous System Diseases ; chemically induced ; epidemiology ; physiopathology ; Sensation Disorders ; chemically induced ; epidemiology ; physiopathology ; Water Pollutants, Chemical ; analysis ; toxicity ; Young Adult

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.