What is essential remains invisible to the eyes? Blood pressure cuffs colonized by bacterial diversity.

Using sphygmomanometers to measure blood pressure is a common practice in the healthcare context. The disinfection and maintenance of these devices is essential in clinical practice to prevent the proliferation of microorganisms. The aim of this study was to determine the presence of pathogenic microorganisms in sphygmomanometer cuffs in the clinical setting. A cross-sectional study was carried out. Five types of healthcare centers, selected through convenience sampling, participated in this study. Samples were collected from the inside of sphygmomanometer cuffs, and labeled and delivered to the laboratory for analysis. The samples were incubated in an oven at 35.5 °C for 24 h. A total CFU count was carried out on the plates that were cataloged as positive. Colonies that showed growth were identified using the matrix-assisted laser desorption/ionization-mass spectrometry technology. Of the total sample, (N = 372), 69.1% were positive and were isolated. In 30.9% (n = 115), no bacterial development was found within 48 h. A total of 257 microorganisms were found. The mean number of colony-forming units was 29.62 (SD = 32.33). The socio-health centers had the highest amount of bacterial contamination in the cuffs. In regards to the type of microorganisms, 31.5% (n = 81) found were Bacillus cereus, followed by 26.8% (n = 69) of Staphylococcus hominis and 9.7% (n = 25) were Pantoea agglomerans, among others. Statistically significant differences were found between the type of microorganism and the hours elapsed since the last disinfection (X2(19) = 44.582; p = 0.001). Statistically significant differences were found between the time elapsed since the last disinfection and the type of sphygmomanometer (X2 (2) = 117.752; p = 0.000). Despite the fact that most hospitals and health centers have established infection control policies and protocols, the results of this study indicate the presence of pathogenic microorganisms in blood pressure cuffs in the clinical setting.

Reducing amount of contrast agent after compression of right brachial artery using a blood pressure cuff in computed tomography cerebrovascular angiography.

OBJECTIVE: To invastgate feasibility of low-dose contrast agent in cerebral computed tomography angiography (CTA) to alleviate side effects. METHOD: Siemens' Somatom Definition AS+CT scanner, Heine's blood pressure monitor G7-M237 (BP cuff) and Ultravist contrast agent (370 mg Iodine/ml) are used. CTA is acquired using following scan parameters including slice thickness of 1mm, image acquisition parameters of 128×0.6 mm, pitch size of 0.8 mm, 175 effective mAs, 120 kVp tube voltage, scan delay time of 3 seconds, and the scan time of 4 seconds. This study is conducted by securing the IV route in the left antecubital vein before injection of contrast agent, wrapping BP cuff around the branchial artery of the opposite right arm after setting the pressure to 200 mmHg. Then, the injection rate of the contrast agent is fixed at 4.5 cc/sec and contrast agent was injected in three different amounts (70, 80, and 100 cc). Bp cuff is released from this moment when HU value reachs 100. RESULT: In this study, the mean HU values measured from common carotid artery are 412.45±5.89 when injecting 80cc contrast agent and using BP cuff and 399.64±5.51 when injecting 100 cc contrast agenet and not using BP cuff, respectively. In middle cerebral artery M1, the mean HU values are 325.23±38.29 when injecting 80cc contrast agent and using BP cuff and 325.00±30.63 when injecting 100cc contrast agent blood and not using pressure cuff, respectively. Difference of mean HU values is not statistically significant (p > 0.05) with and without using BP cuff. CONCLUSION: This study demonstrates that reducing amount of contrast agent is possible when the right brachial artery is compressed using BP cuff. Study results indicate that reducing 20% injection of contrast agent in CT cerebrovascular angiography can still yield comparable imaging results with conventional contrast angent usage, which implies that less side effects are expected with a contrast agent injection. Thus, this study can serve as a reference for potential reducing side effect during CT cerebrovascular angiography.

Modulation of Pulse Propagation and Blood Flow via Cuff Inflation-New Distal Insights.

In standard critical care practice, cuff sphygmomanometry is widely used for intermittent blood pressure (BP) measurements. However, cuff devices offer ample possibility of modulating blood flow and pulse propagation along the artery. We explore underutilized arrangements of sensors involving cuff devices which could be of use in critical care to reveal additional information on compensatory mechanisms. In our previous work, we analyzed the response of the vasculature to occlusion perturbations by means of observations obtained non-invasively. In this study, our aim is to (1) acquire additional insights by means of invasive measurements and (2) based on these insights, further develop cuff-based measurement strategies. Invasive BP experimental data is collected downstream from the cuff in two patients monitored in the OR. It is found that highly dynamic processes occur in the distal arm during cuff inflation. Mean arterial pressure increases in the distal artery by 20 mmHg, leading to a decrease in pulse transit time by 20 ms. Previous characterizations neglected such distal vasculature effects. A model is developed to reproduce the observed behaviors and to provide a possible explanation of the factors that influence the distal arm mechanisms. We apply the new findings to further develop measurement strategies aimed at acquiring information on pulse arrival time vs. BP calibration, artery compliance, peripheral resistance, artery-vein interaction.

Cuff Under Pressure for Greater Accuracy.

PURPOSE OF REVIEW: To present the evidence that describes what is being measured by upper-arm cuff blood pressure (BP) and the level of accuracy compared with invasive central aortic and brachial BP. Potential causes of inaccuracy and emerging methods are also discussed. RECENT FINDINGS: On average cuff systolic BP systematically underestimates invasive brachial systolic BP, although in a given individual it may substantially under- or over-estimate central aortic systolic BP. Such errors may affect individual health management outcomes and distort population level data on hypertension prevalence and control. Oscillometric cuff BP is particularly susceptible to inaccuracy in people with high arterial stiffness and with pathophysiological BP waveform shapes. Emerging cuff-less BP methods will be susceptible to inaccuracy if oscillometric cuff BP is used for calibration. The original purpose of cuff BP was to estimate central aortic BP. Recent evidence has shown substantial inaccuracy of oscillometric cuff BP exists for the measurement of invasive central aortic and brachial BP. Thus, development of more accurate BP methods, through better understanding of oscillometric and BP waveform morphology, is needed to improve health outcomes related to high BP.

Measuring Blood Pressure: from Cuff to Smartphone.

PURPOSE OF REVIEW: For measurement of blood pressure, using inflatable cuff-based technology can be inconvenient, uncomfortable, and requires special equipment. These issues could be overcome by using a contactless technology that measures blood pressure with the ubiquitous smartphone. RECENT FINDINGS: In a proof of concept study involving normotensive participants, Luo et al. demonstrated brachial blood pressure measurements from video of the face with accuracy comparable to traditional automated blood pressure monitors. There is still some way to go before contactless blood pressure measurement technology is sufficiently accurate and robust for clinical use. For example, variations in skin tone and lighting conditions must be addressed. Further, new predictive features will be necessary to reveal added information about blood pressure and thus improve prediction accuracy. New tools are likely to encourage blood pressure measurements in more people, in more places, and with more regularity than ever before.

Eliminating Medical Device-Related Pressure Injury From Blood Pressure Cuffs During Continuous Monitoring in the Perioperative Setting: A Novel Approach.

Hospital-acquired pressure injuries have a significant impact on quality of life. Health care organizations continually strive to improve care and patient satisfaction, for the well-being of the patient and the fiscal health of the organization. A commitment to protecting skin and reducing risk for pressure injury in the perioperative setting is gaining momentum.

Clinical Question: In women who have undergone breast cancer surgery, including lymph node removal, do blood pressure measurements taken in the ipsilateral arm increase the risk of lymphedema?

Throughout the healthcare industry fears of taking blood pressure in arm of patients who have undergone breast cancer surgery have been propagated for decades and continue to be recommended by multiple medical societies and healthcare organizations. However, these precautions are not well based on evidence-based medicine and may have a more historical and traditional basis. The purpose of this study was to review current evidence-based research as well as current guidelines regarding ipsilateral arm blood pressure measurements in women who have undergone breast surgery for cancer including lymph node removal.

Clinical Inquiry-In women who have undergone breast cancer surgery, including lymph node removal, do blood pressure measurements taken in the ipsilateral arm increase the risk of lymphedema?

Throughout the healthcare industry fears of taking blood pressure in the arms of patients who have undergone breast cancer surgery have been propagated for decades and continue to be recommended by multiple medical societies and healthcare organizations. However, these precautions are not well based on evidence-based medicine and may have a more historical and traditional basis. The purpose of this study was to review current evidence-based research as well as current guidelines regarding ipsilateral blood pressure measurements in women who have undergone breast surgery for cancer including lymph node removal.

Clinical Inquiry-In women who have undergone breast cancer surgery, including lymph node removal, do blood pressure measurements taken in the ipsilateral arm increase the risk of lymphedema?

Throughout the healthcare industry fears of taking blood pressure in the arm of patients who have undergone breast cancer surgery have been propagated for decades and continue to be recommended by multiple societies and healthcare organizations. However, these precautions are not well based on evidence-based medicine and may have a more historical and traditional basis. The purpose of this study was to review current evidence-based research as well as current guidelines regarding ipsilateral arm blood pressure measurements in women who have undergone breast surgery for cancer including lymph node removal.

Preventing the collapse of a peripheral vein during cannulation: an evaluation of various tourniquet techniques on vein compressibility.

BACKGROUND: Venous access can occasionally be difficult to obtain secondary to near-complete compressibility of peripheral veins in some patients. OBJECTIVE: This study utilizes ultrasound to assess vein compressibility with different tourniquet techniques commonly available in the emergency department. METHODS: After approval by the Institutional Review Board, a prospective single-center study was conducted assessing the compressibility of basilic veins with ultrasound. Compressibility was assessed at baseline, use of one proximal tourniquet, two tourniquets (one distal and one proximal), and a proximal blood pressure cuff inflated to 150 mm Hg. Vein compressibility was rated as complete, moderate, or mild after light pressure was applied with the ultrasound probe. RESULTS: One hundred healthy patients were recruited into the study. Ninety-eight subjects had completely compressible basilic veins at baseline. When one tourniquet and two tourniquets were applied, 62 and 31 participants, respectively, demonstrated completely compressible veins. Fisher's exact test comparing one vs. two tourniquets revealed no difference between these two techniques (p = 0.4614). Only two participants continued to have a completely compressible vein after application of the blood pressure cuff with statistical significance by Fisher's exact test compared to both tourniquet groups (p < 0.0001). CONCLUSIONS: Both tourniquets and blood pressure cuffs can decrease the compressibility of peripheral veins. Although no difference was identified between one and two tourniquets, utilization of blood pressure cuffs significantly decreased compressibility. The findings of this study can be utilized in the emergency department when attempting to obtain peripheral venous access, specifically supporting the use of blood pressure cuffs to decrease compressibility.

Current state of affairs: A study regarding diagnosis, treatment and use of home blood pressure monitoring for hypertension in pregnancy.

Guidelines for management of hypertension (HTN) in pregnancy have evolved to recommend "tight" control and increased use of home blood pressure (BP) monitoring. This survey-based study examined the preferred methods for diagnosing, investigating and managing HTN in pregnancy among two groups of prenatal care providers at a tertiary care hospital: Family Physicians and Obstetricians. The response rate was 75%. Obstetricians were significantly more likely to use home BP monitoring while Family Physicians were significantly more likely to use 24-hour ambulatory BP monitoring to aid with diagnosis (p = 0.008). For surveillance, more Obstetricians believed home BP monitoring was validated in pregnancy (78.3% vs 42.9%, p = 0.02) and were more likely to monitor HTN with home readings compared to Family Physicians (91.7% vs 64.3%, p = 0.02). Family Physicians were significantly more likely to target "tight" BP control compared to Obstetricians (93.8% vs 72%, p = 0.03). This single centre study demonstrated relatively high uptake of newer BP target recommendations in pregnancy, however there remains a significant variation in the use of home BP monitoring for diagnosis and surveillance of HTN in pregnancy between the two specialties.

Improving Accurate Blood Pressure Cuff Allocation in Patients with Obesity: A Quality Improvement Initiative.

Accurate noninvasive blood pressure (NIBP) measurement requires use of an appropriately sized cuff. We aimed to improve the perioperative allocation of NIBP cuffs in patients with Class II-III obesity. In the baseline evaluation, we measured the mid-arm circumference (MAC) of 40 patients with BMI > 35 kg/m2, documenting the corresponding cuff allocated by pre-operative nurses. The intervention consisted of the introduction of cuff allocation based on MAC measurement and augmented NIBP cuff supplies. We completed a re-evaluation and evaluation of the intervention by staff survey, using 5-point Likert scales and free text comments. At baseline, the correct cuff was allocated in 9 of 40 patients (22.5%). During the intervention, education occurred in 54 (69.2%) peri-operative nursing staff. Upon re-evaluation, the correct cuff was allocated in 30 of 40 patients (75.0%), a statistically significant improvement (χ2 = 22.1, p < 0.001). Ninety-three of 120 staff surveys were returned (78%). Eleven out of 18 preoperative staff surveyed (61.1%) felt confident measuring the arm and selecting the correct cuff. Six (33%) agreed that taking the arm measurement added a lot of extra work. Equipment shortages, accuracy concerns, and clinical workarounds were reported by staff. Our intervention increased the proportion of correct cuffs allocated, but equipment and practical issues persist with NIBP cuff selection in obese patients.

Perioperative Considerations in Osteogenesis Imperfecta: A 20-Year Experience with the Use of Blood Pressure Cuffs, Arterial Lines, and Tourniquets.

Osteogenesis imperfecta (OI) is a rare genetic connective-tissue disorder with bone fragility. To avoid iatrogenic fractures, healthcare providers have traditionally avoided using non-invasive blood pressure (NIBP) cuffs and extremity tourniquets in the OI population in the perioperative setting. Here, we hypothesize that these procedures do not lead to iatrogenic fractures or other complications in patients with OI. A retrospective study of all children with OI who underwent surgery at a single tertiary care children's hospital from 1998 to 2018 was performed. Patient positioning and the use of NIBP cuffs, arterial lines, and extremity tourniquets were documented. Fractures and other complications were recorded. Forty-nine patients with a median age of 7.9 years (range: 0.2-17.7) were identified. These patients underwent 273 procedures, of which 229 were orthopaedic operations. A total of 246 (90.1%) procedures included the use of an NIBP cuff, 61 (22.3%) an extremity tourniquet, and 40 (14.7%) an arterial line. Pediatric patients with OI did not experience any iatrogenic fractures related to hemodynamic monitoring or extremity tourniquet use during the 20-year period of this study. Given the benefits of continuous intra-operative hemodynamic monitoring and extremity tourniquets, we recommend that NIBP cuffs, arterial lines, and tourniquets be selectively considered for use in children with OI.

Comparison of blood pressure measurements in the upper and lower extremities versus arterial blood pressure readings in children under general anesthesia.

PURPOSE: To compare invasive blood pressure (IBP) readings obtained from an arterial cannula with non-invasive blood pressure (NIBP) measurements from oscillometric cuffs on the upper and lower extremities of infants and children under general anesthesia. PATIENTS AND METHODS: Patients under 10 years of age were enrolled in our study if they were to receive general anesthesia with planned placement of a radial arterial cannula. At 5 mins intervals, IBP was measured using a fluid-coupled pressure transducer and NIBP was measured with two oscillometers with appropriately sized cuffs placed on the upper arm and lower leg, for 10 readings per patient. RESULTS: The study enrolled 18 boys and 12 girls, ranging in age from 0 to 8 years. Across 300 data points, the absolute difference between the arm and invasive mean arterial pressure (MAP) measurements was 7±7 mmHg (range: 0-52 mmHg). The absolute difference between the leg and invasive MAP measurements was 8±8 mmHg (range: 0-52 mmHg). Although both non-invasive measurement sites demonstrated frequent deviation from invasive measurement, large deviations were more common when BP was measured at the leg (81 of 298 observations (27%) deviating by >10 mmHg) compared to the arm (60 of 300 observations (20%) deviating by >10 mmHg). CONCLUSION: The frequency of clinically significant NIBP deviation in children under general anesthesia supports the importance of IBP monitoring when hemodynamic fluctuations are likely and would be particularly detrimental. NIBP measured at the lower leg is more likely to result in clinically significant deviation from invasively measured MAP than NIBP values obtained from an upper arm.

Efficacy of an Ethanol-Based Hand Sanitizer for the Disinfection of Blood Pressure Cuffs.

Blood pressure cuffs (BP cuffs) have been implicated in some nosocomial outbreaks. We compared the efficacy of an ethanol-based hand sanitizer (EBHS) with a detergent/disinfectant for the disinfection of BP cuffs. The inner sides of 30 BP cuffs were sampled for bacterial culture. Then, the same area was divided into halves. One half was disinfected by a detergent/disinfectant and the other was disinfected by an EBHS. The bacterial count decreased significantly with both disinfectants (p < 0.0001 compared with before disinfection). The bacterial count decrease seemed greater with the EBHS compared with the detergent/disinfectant, but the difference was not significant. Therefore, within the limits of a single application, the EBHS was an efficacious means of BP cuff disinfection. However, the repeated exposure to emollients contained in EBHS may require further studies before validating these results.

Equivalence between invasive and oscillometric blood pressures at different anatomic locations in healthy normotensive anaesthetised horses.

REASONS FOR PERFORMING STUDY: Accurate blood pressure measurement is essential for effective clinical assessment and appropriate interventions in anaesthetised horses. Information on the accuracy of oscillometry for blood pressure measurement on the appendages of mature horses is limited. OBJECTIVES: To assess equivalence between invasive and oscillometric blood pressures at different anatomic locations in horses. STUDY DESIGN: Prospective experimental study using 6 healthy mature horses. METHODS: Blood pressure was measured invasively in the right transverse facial artery and noninvasively by oscillometry in nondependent limbs and tail of laterally recumbent sevoflurane- or desflurane-anaesthetised horses. Cuff widths of 5-12 cm were tested on the tail, metatarsus, metacarpus and distal radius/ulna. Equivalence between mean arterial pressure (MAP) oscillometric and MAP invasive was assessed using a linear mixed effects model with a significance level of P≤0.05. RESULTS: Twenty paired measurements were obtained for each cuff size in each of the locations, totalling 340 measurements. There was only one location (tail) and one cuff width (6 cm; cuff width-to-tail circumference ratio of 0.25) that resulted in equivalence between MAP measured with the oscillometric and the invasive methods (P = 0.8). All other locations (metacarpus, radius/ulna, metatarsus) and cuff widths were not equivalent (P≤0.01). CONCLUSIONS: A cuff width-to-tail circumference ratio of 0.25 is recommended for accurate oscillometric blood pressure measurement in mature, laterally recumbent anaesthetised normotensive horses. Studies with variable haemodynamics are warranted. Oscillometric measurements at other extremities and/or with other cuff sizes cannot be recommended for clinical use.

Sphygmomanometer cuffs: a potential source of infection!

We evaluated the potential pathogenic hazard of sphygmomanometer blood pressure cuffs (BPCs) in a hospital setting. Prospectively, the presence of bacterial organisms on 120 BPCs in 14 medical wards and outpatient clinics in a district general hospital in London was assessed. Swabs taken from the inner aspect of the cuffs were cultured using standard microbiological techniques. Bacterial organisms were found in 85% (102) of the 120 BPCs assessed. The highest rates of contamination were found in the outpatients department (90%). There were differences in the most common bacterial species isolated between the samples obtained from the outpatient clinics and the wards, with coagulase-negative Staphylococcus and diphtheroids being the most prevalent species in the wards and outpatient clinics, respectively. These findings highlight the necessity to eliminate this potential risk of infection.

Comparison of indirect and direct blood pressure monitoring in normotensive swine.

The gold standard for blood pressure measurement in pigs is direct monitoring of arterial pressure, but this is an invasive technique adding complexity to surgical procedures. We sought to compare direct measurements obtained via catheterization to more easily-obtained indirect measurements using a sphygmomanometer with an automated cuff. Simultaneous measurements via an arterial pressure transducer and a child-size cuff were performed in pigs undergoing abdominal surgical procedures under normotensive conditions. Correlation between direct and indirect measurements was good (r=0.881). Systolic blood pressures for the cuff were higher than those for arterial measurements, while diastolic pressures were lower for the cuff than arterial. A Bland-Altman analysis confirmed this bias at the extremes of the normotensive range. For highly accurate readings, especially under stressed conditions, direct arterial catheterization remains the preferred method of measuring blood pressure. When monitoring surgical procedures, the more convenient blood pressure cuff can provide reliable measurements.