Correlation of patient characteristics with arm and finger measurements in Asian parturients: a preliminary study

Background: Accurate blood pressure (BP) measurement depends on appropriate cuff size and shape in relation to the arm. Arm dimensions outside the recommended range of cuff sizes or trunco-conical arms may result in inaccurate BP measurements. Measuring BP using finger cuffs is a potential solution. Arm cuff size is based on mid-arm circumference (MAC), and trunco-conicity is quantified by conicity index. We aimed to determine the correlation of MAC, body mass index (BMI), and weight with conicity index.Methods: A prospective cohort study was conducted in the KK Women’s and Children’s hospital where third trimester parturients scheduled for cesarean delivery were recruited after obtaining informed consent. Parturients were asked to rate their experience with time taken to obtain BP readings, cuff popping off during measurement, need to move the cuff from the upper arm to lower arm or leg, and need to change to a different cuff. Our primary outcome was the correlation between MAC and conicity index, calculated using Pearson’s correlation. The correlation between BMI and weight with conicity index was also determined.Results: We enrolled 300 parturients. Moderate correlation was found between left MAC and left conicity index (r=0.41, 95% CI 0.32 to 0.51), and right MAC and right conicity index (r=0.39, 95% CI 0.29 to 0.48). Weight (r=0.35 to 0.39) and BMI (r=0.41 to 0.43) correlated with conicity index in this study. MAC of 1 parturient fell outside the recommended range for arm cuffs, but all parturients fit into available finger cuffs. Obese parturients had increased problems with arm cuffs popping off and needing a change of cuff.Conclusions: BMI better correlated with conicity index compared to MAC or weight. Standard finger cuffs were suitable for all parturients studied and may be a suitable alternative.Trial registration: Clinicaltrials.gov NCT04012151. Registered 9 Jul 2019 https://clinicaltrials.gov/ct2/show/NCT04012151

Correlation of patient characteristics with arm and finger measurements in Asian parturients: a preliminary study

Background: Accurate blood pressure (BP) measurement depends on appropriate cuff size and shape in relation to the arm. Arm dimensions outside the recommended range of cuff sizes or trunco-conical arms may result in inaccurate BP measurements. Measuring BP using finger cuffs is a potential solution. Arm cuff size is based on mid-arm circumference (MAC), and trunco-conicity is quantified by conicity index. We aimed to determine the correlation of MAC, body mass index (BMI), and weight with conicity index.Methods: A prospective cohort study was conducted in the KK Women’s and Children’s hospital where third trimester parturients scheduled for cesarean delivery were recruited after obtaining informed consent. Parturients were asked to rate their experience with time taken to obtain BP readings, cuff popping off during measurement, need to move the cuff from the upper arm to lower arm or leg, and need to change to a different cuff. Our primary outcome was the correlation between MAC and conicity index, calculated using Pearson’s correlation. The correlation between BMI and weight with conicity index was also determined.Results: We enrolled 300 parturients. Moderate correlation was found between left MAC and left conicity index (r=0.41, 95% CI 0.32 to 0.51), and right MAC and right conicity index (r=0.39, 95% CI 0.29 to 0.48). Weight (r=0.35 to 0.39) and BMI (r=0.41 to 0.43) correlated with conicity index in this study. MAC of 1 parturient fell outside the recommended range for arm cuffs, but all parturients fit into available finger cuffs. Obese parturients had increased problems with arm cuffs popping off and needing a change of cuff.Conclusions: BMI better correlated with conicity index compared to MAC or weight. Standard finger cuffs were suitable for all parturients studied and may be a suitable alternative.Trial registration: Clinicaltrials.gov NCT04012151. Registered 9 Jul 2019 https://clinicaltrials.gov/ct2/show/NCT04012151

Arm and finger measurements in pregnant Asian parturients and their implications on blood pressure measurement: a prospective cohort study

Background Accurate blood pressure (BP) measurement depends on appropriate cuff size and shape in relation to the arm. Arm dimensions outside the recommended range of cuff sizes or trunco-conical arms may result in inaccurate BP measurements. Measuring BP using finger cuffs is a potential solution. Arm cuff size is based on mid-arm circumference (MAC), and trunco-conicity is quantified by conicity index. We aimed to determine the correlation of MAC, body mass index (BMI), and weight with conicity index. Methods A prospective cohort study was conducted in the KK Women’s and Children’s hospital where third trimester parturients scheduled for cesarean delivery were recruited after obtaining informed consent. Parturients were asked to rate their experience with time taken to obtain BP readings, cuff popping off during measurement, need to move the cuff from the upper arm to lower arm or leg, and need to change to a different cuff. Our primary outcome was the correlation between MAC and conicity index, calculated using Pearson’s correlation. The correlation between BMI and weight with conicity index was also determined. Results We enrolled 300 parturients. Moderate correlation was found between left MAC and left conicity index (r = 0.41, 95% CI 0.32 to 0.51), and right MAC and right conicity index (r = 0.39, 95% CI 0.29 to 0.48). Weight (r = 0.35 to 0.39) and BMI (r = 0.41 to 0.43) correlated with conicity index in this study. MAC of 1 parturient fell outside the recommended range for arm cuffs, but all parturients fit into available finger cuffs. Obese parturients had increased problems with arm cuffs popping off and needing a change of cuff. Conclusions BMI better correlated with conicity index compared to MAC or weight. Standard finger cuffs were suitable for all parturients studied and may be a suitable alternative. Trial registration: Clinicaltrials.gov NCT04012151. Registered 9 Jul 2019 https://clinicaltrials.gov/ct2/show/NCT04012151

Relationship Between Interface Pressures and Pneumatic Cuff Inflation Pressure at Different Assessment Sites of the Lower Limb to Aid Soft Exoskeleton Design

Objective The aim was to develop a means of predicting interface pressure from cuff inflation pressure during circumferential compression at the lower limb, in order to inform the design of soft exoskeletons. Background Excessive mechanical loading of tissues can cause discomfort and soft tissue injury. Most ergonomic studies on exoskeletons are of interface pressure, but soft exoskeletons apply circumferential pressures similar to tourniquet cuffs by way of cuff inflation pressure. This study details the relationship between interface and cuff inflation pressures for pneumatic tourniquet cuffs. Method Pneumatic cuffs of different widths were inflated to target pressures on (A) a rigid cylinder, (B) the dominant thigh and calf, and (C) knee of healthy participants standing still. Interface pressures were measured under the cuffs using a pressure-sensing mat. Average interface pressures were then compared to cuff inflation pressures. The influence of cuff width, cuff inflation pressure, and participants’ anthropometric data on pressure transmission was assessed. Results A strong linear relationship between cuff inflation pressures and interface pressures was observed. Interface pressures were generally higher than cuff inflation pressures. The efficiency of pressure transmission to the lower limb depended on assessment site, adipose tissue thickness, cuff size, cuff inflation pressure, and possibly limb circumference. Regression equations were developed to predict interface pressures at the thigh, calf, and knee. Conclusion Interface pressures under pneumatic cuffs are influenced by the cuff size, cuff inflation pressure, and tissue compressibility. Predicted interface pressure from cuff inflation pressure and vice versa can be used to aid the design of soft exoskeletons.

Penoscrotal Incision for the Primary Implantation of an Artificial Urinary Sphincter

Background: The artificial urinary sphincter (AUS) has become the gold standard to treat severe stress urinary incontinence in men. The traditional placement of an AUS requires 2 incisions. The cuff is placed through a perineal incision and the reservoir and pump are placed via an inguinal incision. The implantation of an AUS is also possible via a single penoscrotal approach. Objectives: The objective is to demonstrate that the penoscrotal approach is not inferior to the perineal approach. Methods: Retrospective review of a single surgeon database from 2014 to 2019 was performed. A total of 40 patients have undergone implantation of an AUS via a penoscrotal incision. The outcome of patients was followed for an average of 31.3 months for adverse outcomes. Results: A primary American Medical Systems 800 sphincter was placed in 40 patients via a penoscrotal incision. The average age was 72 years. The average operating time was 35 minutes. The average cuff size was 4 cm. There were no infections of the prothesis so far. Three patients required a revision, 2 other patients needed an explant of the AUS, 1 patient underwent a cystectomy because of persistent radiocystitis. After activation of the sphincter, 33 patients (82.5%) were completely dry or using 1 pad per day for accidents. The remainder were all improved. Conclusions: AUS implantation via a single penoscrotal approach is not inferior to the perineal approach and has several advantages. The operating time is shorter and the procedure requires only 1 incision which both reduce the risk of infections, while the continence results are similar for both approaches.