Cuff Pressure Research Articles

Measuring blood pressure from Korotkoff sounds as the brachial cuff inflates on average provides higher values than when the cuff deflates

Objective. In this study, we test the hypothesis that if, as demonstrated in a previous study, brachial arteries exhibit hysteresis as the occluding cuff is deflated and fail to open until cuff pressure (CP) is well below true intra-arterial blood pressure (IABP). Approach Estimating systolic (SBP) and diastolic blood pressure (DBP) from the presence of Korotkoff sounds as CP increases may eliminate these errors and give more accurate estimates of SBP relative to IABP readings. Main Results. In 63 subjects of varying age 45.4 ± 19.9 years (range 21–76 years), including 44 men (45.2 ± 19.5, range 21–76 years) and 19 women (45.6 ± 21.4, range 21–75 years), there was a significant (p < 0.0001) increase in SBP from 124.4 ± 15.7 to 129.2 ± 16.3 mmHg and a significant (p < 0.0001) increase in DBP from 70.2 ± 10.7 to 73.6 ± 11.5 mmHg. Of the 63 subjects, 59 showed a positive increase in SBP (1–19 mmHg) and 5 subjects showed a reduction (−5 to −1 mmHg). The average differences for SBP estimates derived as the cuff inflates and estimates derived as the cuff deflates were 4.9 ± 4.7 mmHg, not dissimilar to the differences observed between IABP and NIBP measurements. Although we could not develop multiparameter linear or nonlinear models to explain this phenomenon we have clearly demonstrated through analysis of variance test that both body mass index (BMI) and pulse wave velocity are implicated, supporting the hypothesis that the phenomenon is associated with age, higher BMI and stiffer arteries. Significance. The implications of this study are potentially profound requiring the implementation of a new paradigm for NIBP measurement and a revision of the international standards for their calibration.

The Effect of the Endotracheal Cuff and Alveolar Pressures on Laryngopharyngeal Outcomes in Laparoscopic and Open Gynecological Procedure

The Effect of the Endotracheal Cuff and Alveolar Pressures on Laryngopharyngeal Outcomes in Laparoscopic and Open Gynecological Procedure

Body image dissatisfaction and experimental pressure pain sensitivity in a cohort of 13-year-old adolescents

ObjectiveWe aimed to quantify the associations between body image (dis)satisfaction and pressure pain thresholds in adolescents, using data from Generation XXI, a population-based cohort study in Portugal. MethodsWe assessed 1785 13-year old adolescents cross-sectionally. Body image satisfaction was measured using the Children's Figure Rating Scale. Pain detection and tolerance thresholds were assessed using cuff pressure algometry. We quantified the associations between body image categories (satisfied, prefers slightly thinner, prefers much thinner, and prefers heavier) and pain detection and tolerance thresholds using linear and logistic regression for continuous and binary (odds of achieving the highest distribution quarter) outcomes, respectively. Models were adjusted to pubertal stage and body mass index. ResultsAdolescents who desired a heavier silhouette had lower pressure pain tolerance thresholds when compared to those who were satisfied (linear regression coefficient: −3.95; 95% confidence interval: −6.68, −1.21), which was more precise in boys (−3.51; −7.17, −0.08). Those adolescents also had lower odds of achieving the highest quarter of pressure pain tolerance threshold (odds ratio: 0.66; 0.48, 0.90), especially girls (0.58; 0.35, 0.98). Adolescents who desired much thinner silhouettes had lower odds of achieving the highest quarter of pressure pain tolerance (0.68; 0.46, 1.00), and this was clearer in girls (0.66; 0.48, 0.90). Pain detection thresholds did not show robust associations with body image dissatisfaction. ConclusionOur study suggests an association between satisfaction with one's silhouette and pain tolerance in adolescents from the general population, arguing for an integrated approach to the assessment of body image and pain sensitivity.

Risk Factors and Protective Factors against Ventilator-Associated Pneumonia-A Single-Center Mixed Prospective and Retrospective Cohort Study.

Introduction: Understanding the factors associated with the development of ventilator-associated pneumonia (VAP) in critically ill patients in the intensive care unit (ICU) will allow for better prevention and control of VAP. The aim of the study was to evaluate the incidence of VAP, as well as to determine risk factors and protective factors against VAP. Design: Mixed prospective and retrospective cohort study. Methods: The cohort involved 371 critically ill patients who received standard interventions to prevent VAP. Additionally, patients in the prospective cohort were provided with continuous automatic pressure control in tapered cuffs of endotracheal or tracheostomy tubes and continuous automatic subglottic secretion suction. Logistic regression was used to assess factors affecting VAP. Results: 52 (14%) patients developed VAP, and the incidence density of VAP per 1000 ventilator days was 9.7. The median days to onset of VAP was 7 [4; 13]. Early and late onset VAP was 6.2% and 7.8%, respectively. According to multivariable logistic regression analysis, tracheotomy (OR = 1.6; CI 95%: 1.1 to 2.31), multidrug-resistant bacteria isolated in the culture of lower respiratory secretions (OR = 2.73; Cl 95%: 1.83 to 4.07) and ICU length of stay >5 days (OR = 3.32; Cl 95%: 1.53 to 7.19) were positively correlated with VAP, while continuous control of cuff pressure and subglottic secretion suction used together were negatively correlated with VAP (OR = 0.61; Cl 95%: 0.43 to 0.87). Conclusions: Tracheotomy, multidrug-resistant bacteria, and ICU length of stay >5 days were independent risk factors of VAP, whereas continuous control of cuff pressure and subglottic secretion suction used together were protective factors against VAP.

Subject factors influencing blood flow restriction in the arm at low cuff pressures.

Limb circumference predicts the pressure needed for complete occlusion. However, that relationship is inconsistent at moderate pressures typical of effective blood flow restriction (BFR) training. The purpose of this study was to investigate the influence of subject factors on BFR at low restriction pressures in the arm. Fifty subjects had arm anthropometrics assessed by peripheral quantitative computed tomography (pQCT), sum of skinfold thickness (sumSKF) and Gulick tape (Gulick tape circumference [Gulick Circ.]) at cuff level. Blood flow (BF) was measured with ultrasound at baseline and five restrictive pressures (20, 30, 40, 50 and 60 mmHg). Relationships between subject characteristics and BFR were assessed using Pearson's correlations and hierarchical regression. BF decreased (p < 0.05) at each incremental pressure. Regression models including percent muscle composition (%Muscle), pQCT circumference and systolic blood pressure (SBP), were significant at all five pressures (R2 = 0.18-0.49). %Muscle explained the most variance at each pressure. Regression models including sumSKF, Gulick Circ. and SBP, were significant at 30-60 mmHg (R2 = 0.28-0.49). SumSKF explained the most variance at each pressure. At low pressures (20-60 mmHg), there is considerable variability in the magnitude of BFR across individuals. Arm composition factors (muscle and fat) explained the greatest variance at each cuff pressure and may be the most important consideration when using BFR protocols.

A prospective observational study on changes in endo-tracheal tube cuff pressure and its correlation with airway pressures during various stages of robotic pelvic surgeries.

Background and Aims:Robotic surgeries often require a relatively long duration of pneumo-peritoneum and trendelenburg position which may accentuate changes in endo-tracheal tube (ETT) cuff pressure leading to pressure related complications. The aim of this study was to analyze changes in ETT cuff pressures during various stages of pneumo-peritoneum and surgical positioning and its correlation with airway pressure changes.Material and Methods:A prospective observational study was planned after approval of institutional review board on 60 patients undergoing elective robotic pelvic surgery requiring head down position. Baseline cuff pressure was adjusted to 25 cm H2O. ETT cuff pressure, peak airway pressure and end tidal CO2 (ETCO2) was measured at various time intervals before and after pneumo-peritoneum and head down. Ventilatory parameters were kept fixed after baseline setting. Those requiring any change were excluded. Pearson’s coefficient was used for correlation and ANOVA for trend of parameters at different time intervals (P value <0.05 was considered significant).Results:Baseline cuff pressure after manual inflation was 46.2 ± 17.4 cm H2O. Significant correlation was observed between change in cuff pressure and increase in peak airway pressure at the end of the surgery (r = 0.4, P < 0.05). Serial measurements of ETT cuff pressure, peak airway pressure and ETCO2 were significantly increased compared to baseline (P < 0.05).Conclusion:Significant increases in ETT cuff pressure may be seen in robotic surgeries, with a positive correlation between change in cuff pressure and increase in airway pressures. Objective adjusted measurement of cuff pressure and airway pressures is recommended for such surgeries.

370 Developing a Digitally Integrated Endotracheal Tube for Neonates to Improve Safety and Respiratory Function

OBJECTIVES/GOALS: Neonatal endotracheal tubes (ETTs) are usually uncuffed to avoid subglottic stenosis and other complications, but cuffed ETTs allow better ventilation. Our goal was to detect and control pressure in the cuff below the limit of occluding venous flow to minimize the risk of subglottic stenosis. METHODS/STUDY POPULATION: We designed a pressure sensor to fit on a 2.5 ETT for prototype testing in 8 age adult female rabbits. Eight uncuffed age- and sex- matched rabbits served as control. Study duration was 2 hours during which pressure in the cuff was limited by novel sensor (intervention) or auscultation (control). Anesthesia was maintained with sevoflurane. Ventilation was provided mechanically. Subsequently the tracheae were removed, sectioned crosswise, and compared histologically for mucosal damage. RESULTS/ANTICIPATED RESULTS: Preliminary data demonstrated an almost 30% greater amount of intact mucosa in the intervention group. The sensor also provided data on heart rate and respiratory rate, although this signal was not optimal. After filing an invention disclosure and provisional patent, we are refining our device to include multiple compartments for local control of cuff pressure and applying for a STTR Phase I/II application. DISCUSSION/SIGNIFICANCE: Ventilation in neonates with uncuffed ETTs can be suboptimal due to leak around the tube, but cuffed ETTs pose the threat of subglottic stenosis and other complications. We have designed a prototype cuffed ETT with a sensor to maintain low cuff pressure while preventing leaks and largely avoiding damage to the tracheal mucosa.

312 Developing a Digitally Integrated Endotracheal Tube for Neonates to Improve Safety and Respiratory Function

OBJECTIVES/GOALS: Neonatal endotracheal tubes (ETTs) are usually uncuffed to avoid subglottic stenosis and other complications, but cuffed ETTs allow better ventilation. Our goal was to detect and control pressure in the cuff below the limit of occluding venous flow to minimize the risk of subglottic stenosis. METHODS/STUDY POPULATION: We designed a pressure sensor to fit on a 2.5 ETT for prototype testing in 8 age adult female rabbits. Eight uncuffed age- and sex- matched rabbits served as control. Study duration was 2 hours during which pressure in the cuff was limited by novel sensor (intervention) or auscultation (control). Anesthesia was maintained with sevoflurane. Ventilation was provided mechanically. Subsequently the tracheae were removed, sectioned crosswise, and compared histologically for mucosal damage. RESULTS/ANTICIPATED RESULTS: Preliminary data demonstrated an almost 30% greater amount of intact mucosa in the intervention group. The sensor also provided data on heart rate and respiratory rate, although this signal was not optimal. After filing an invention disclosure and provisional patent, we are refining our device to include multiple compartments for local control of cuff pressure and applying for a STTR Phase I/II application. DISCUSSION/SIGNIFICANCE: Ventilation in neonates with uncuffed ETTs can be suboptimal due to leak around the tube, but cuffed ETTs pose the threat of subglottic stenosis and other complications. We have designed a prototype cuffed ETT with a sensor to maintain low cuff pressure while preventing leaks and largely avoiding damage to the tracheal mucosa.

Effect of different recovery modes during resistance training with blood flow restriction on hormonal levels and performance in young men: a randomized controlled trial

BackgroundResistance training with blood flow restriction (BFR) results in hypertrophy, and its magnitude depends on various training variables. This study aimed to compare the long-term effect of passive recovery (PR) and active recovery (AR) during low-intensity resistance training with BFR on hormonal levels and performance in young men.MethodsIn the randomized clinical trial, 20 men were randomly divided into PR and AR groups during resistance training with BFR. The intervention consisted of six upper and lower body movements with 30% of one maximum repetition (1RM), three sessions per week for six weeks. Both groups wore pneumatic cuffs on the proximal part of thighs and arms. The cuff pressure was 60% of the calculated arterial blood occlusion and increased 10% every two weeks. The AR group performed seven repetitions in 30 s break between sets by one second for concentric and eccentric phases and two seconds rest, and the other group had passive rest. The blood samples and a series of performance tests were gathered before and after the intervention. A repeated measure ANOVA was used to analyze data.ResultsAR and PR interventions significantly improved the C-reactive protein (CRP) (− 38% vs. − 40%), Lactate dehydrogenase (LDH) (− 11% vs. − 3%), Sargent jump (9% vs. 10%), peak power (20% vs.18%), and average power (14% vs. 14%), upper 1RM (8% vs. 8%) and no significant differences were observed between groups. The AR intervention significantly increased growth hormone (GH) (423% vs. 151%, p = 0.03), lower body 1RM (18% vs. 11%) and muscle endurance (34% vs. 22% for the upper body, p = 0.02 and 32% vs. 24% for the lower body, p = 0.04) than the PR group. The PR intervention further increased the minimum power than the AR group (19% vs. 10%). There were no significant changes in testosterone (p = 0.79) and cortisol (p = 0.34) following interventions.ConclusionThe findings indicated that by increasing muscle activation and higher metabolic load, AR during resistance training with BFR might cause more remarkable improvements in serum GH, muscle strength, and endurance. Thus, to gain further benefits, AR during training with BFR is recommended.Trial registration: IRCT20191207045644N1. Registration date: 14/03/2020. URL: https://www.irct.ir/search/result?query=IRCT20191207045644N1

Physiological Responses to Acute Cycling With Blood Flow Restriction.

Aerobic exercise with blood flow restriction (BFR) can improve muscular function and aerobic capacity. However, the extent to which cuff pressure influences acute physiological responses to aerobic exercise with BFR is not well documented. We compared blood flow, tissue oxygenation, and neuromuscular responses to acute cycling with and without BFR. Ten participants completed four intermittent cycling (6 × 2 min) conditions: low-load cycling (LL), low-load cycling with BFR at 60% of limb occlusion pressure (BFR60), low-load cycling with BFR at 80% of limb occlusion pressure (BFR80), and high-load cycling (HL). Tissue oxygenation, cardiorespiratory, metabolic, and perceptual responses were assessed during cycling and blood flow was measured during recovery periods. Pre- to post-exercise changes in knee extensor function were also assessed. BFR60 and BFR80 reduced blood flow (~33 and ~ 50%, respectively) and tissue saturation index (~5 and ~15%, respectively) when compared to LL (all p < 0.05). BFR60 resulted in lower VO2, heart rate, ventilation, and perceived exertion compared to HL (all p < 0.05), whereas BFR80 resulted in similar heart rates and exertion to HL (both p > 0.05). BFR60 and BFR80 elicited greater pain compared to LL and HL (all p < 0.05). After exercise, knee extensor torque decreased by ~18 and 40% for BFR60 and BFR80, respectively (both p < 0.05), and was compromised mostly through peripheral mechanisms. Cycling with BFR increased metabolic stress, decreased blood flow, and impaired neuromuscular function. However, only BFR60 did so without causing very severe pain (>8 on pain intensity scale). Cycling with BFR at moderate pressure may serve as a potential alternative to traditional high-intensity aerobic exercise.

Dynamic Functional Brain Connectivity Underlying Temporal Summation of Pain in Fibromyalgia.

Abnormal central pain processing is a leading cause of pain in fibromyalgia (FM) and is perceptually characterized with the psychophysical measure of temporal summation of pain (TSP). TSP is the perception of increasingly greater pain in response to repetitive or tonic noxious stimuli. Previous neuroimaging studies have used static (i.e., summary) measures to examine the functional magnetic resonance imaging (fMRI) correlates of TSP in FM. However, functional brain activity rapidly and dynamically reorganizes over time, and, similarly, TSP is a temporally evolving process. This study was undertaken to demonstrate how a complete understanding of the neural circuitry supporting TSP in FM thus requires a dynamic measure that evolves over time. We utilized novel methods for analyzing dynamic functional brain connectivity in patients with FM in order to examine how TSP-associated fluctuations are linked to the dynamic functional reconfiguration of the brain. In 84 FM patients and age- and sex-matched healthy controls, we collected high-temporal-resolution fMRI data during a resting state and during a state in which sustained cuff pressure pain was applied to the leg. FM patients experienced greater TSP than healthy controls (mean ± SD TSP score 17.93 ± 19.24 in FM patients versus 9.47 ± 14.06 in healthy controls; P = 0.028), but TSP scores varied substantially between patients. In the brain, the presence versus absence of TSP in patients with FM was marked by more sustained enmeshment between sensorimotor and salience networks during the pain period. Furthermore, dynamic enmeshment was noted solely in FM patients with high TSP, as interactions with all other brain networks were dampened during the pain period. This study elucidates the dynamic brain processes underlying facilitated central pain processing in FM. Our findings will enable future investigation of dynamic symptoms in FM.

The Effect of Intraoperative Transesophageal Echocardiography Probe Placement on the Endotracheal Tube Cuff Pressure in Adult Patients Undergoing On-Pump Cardiac Surgery

The study was directed toward documentation of the effect of transesophageal echocardiography (TEE) probe insertion on the endotracheal tube cuff pressure (CP) in adult patients undergoing on-pump coronary bypass surgery. The primary objective of this study was to assess whether CP reaches supranormal pressures during the different stages of intraoperative TEE examination. The secondary objective was to observe the effect of TEE probe placement on the ventilation parameters. A prospective observational study. At a tertiary care cardiac center. Thirty-four cardiac surgical patients older than 18 years of age who required intraoperative TEE examination. TEE probe insertion. Following the induction of general anesthesia and tracheal intubation, a TEE probe was introduced. The endotracheal tube CP was recorded at 5 time zones: Before TEE probe insertion, during the insertion of the probe, during probe manipulation, probe in the transgastric position, and during removal of the probe. A nonparametric test was used for comparing intracuff pressure between pairs of time zones. There was a statistically significant difference in CP values between the baseline and those during different time zones (chi-square test=134.77, degrees of freedom=4, p=0.001). There was a statistically significant difference in the peak pressure between different time points compared to baseline (p=0.0001). TEE probe placement in patients with tracheal intubation may be associated with a significant increase in CP well above the baseline pressure. With the possibility of the mean arterial pressures during cardiopulmonary bypass being substantially lower than expected, the findings of the current study raised the concern of predisposing the tracheal mucosa to hypoperfusion, with subsequent temporary or permanent tracheal damage. Hence, at least a baseline estimation of the endotracheal tube CP at the time of tracheal intubation, with the help of a pressure gauge in the operating room, may be considered as a safe practice.

Association between Brachial-Ankle Pulse Wave Velocity as a Marker of Arterial Stiffness and Body Mass Index in a Chinese Population.

Objectives: Arterial stiffness is widely accepted as an important predictor of cardiovascular disease (CVD) development. While obesity is generally associated with increased CVD risk, there is evidence that overweight patients with existing CVD may have better clinical outcomes than their lean counterparts. Our study sought to observe any potential association between brachial–ankle pulse wave velocity (BAPWV), a marker of arterial stiffness related to CVD risk, and Body Mass Index (BMI), a crude and widely used measure of obesity. Methods: Adult individuals (n = 857) assessed for routine CV risk were included and grouped according to their BMI (<25 kg/m2: normal; 25–30 kg/m2: overweight, ≥30 kg/m2: obese). Their anthropometric parameters, brachial cuff pressures, and BAPWV were measured. Results: Brachial pressure was significantly higher as BMI increased. BAPWV showed a positive linear association with systolic (r = 0.66, p < 0.01), mean (r = 0.60, p < 0.01), diastolic (r = 0.51, p < 0.01), and pulse (r = 0.53, p < 0.01) pressures. However, a linear relationship between BMI and BAPWV was only apparent in males aged <50 years (p = 0.01) and in females aged ≥50 years (p < 0.01). In individuals with similar brachial systolic pressure, BAPWV was higher in normal-weight subjects compared to overweight–obese ones. Conclusions: This conflicting finding is attributed to an overestimation of the degree of arterial stiffness as a measure of CVD risk in individuals with a less ‘healthy’ BMI. This suggests that BMI may not the appropriate obesity indicator to assess CV risk. Our finding emphasizes the importance of establishing a non-linear relationship between CVD risk, age, and BMI, taking into account apparent sex differences, to predict future CV events. While this finding may suggest a lower degree of stiffness in large arteries of overweight–obese subjects compared to their normal-weight counterparts, the potential implications for individuals with higher BMI need be explored further.

COMPARISON OF “JUST SEAL” VS “STETHOSCOPE GUIDED” CUFF INFLATION METHOD OF ENDOTRACHEAL TUBE CUFF FOR REDUCTION OF POST OPERATIVE SORE THROAT

Objective: To compare the efficacy of “Just seal” method of endotracheal tube cuff inflation versus “stethoscope guided”method for reduction of frequency of post operative sore throat.&#x0D; Study Design: Prospective observation study.&#x0D; Place and Duration of study: This study was conducted in Main operation theatre, CMH Kohat from 1st September 2018 to 30th November 2018.&#x0D; Patients and methods: 44 patients divided in two groups of 22 each were made, Group JS and Group SG. Inj Propofol and atracurium was used for induction of general anaesthesia, and Inj Nalbuphine was used as analgesic. Endotracheal intubation with 7.5 internal diameter ETT, was done after 3 minutes of injecting atracurium. In group JS, ETT cuff was inflated gradually till no leakage was heard. In group SG, ETT cuff was inflated slowly and stethoscope bell was placed over thyroid lamina till harsh sounds stopped. Age, volume used to inflate cuff, cuff pressure generated and complain of sore throat 02 hours after extubation were noted.&#x0D; Results: Mean age was 30.22 ±4.7 years and 30.13± 4.2 years for Group JS and SG respectively (p=0.946). Mean volume used was 6.81±0.41 ml and 4.95±0.29 ml for Group JS and SG respectively (p=0.000). Mean pressure generated was 34.90±4.48 cmH2O and 28.91±2.37 cmH2O (p=0.000). Frequency of Post operative sore throat was 54.55% (12/22) in JS group and 18.18 % (4/22) in SG group (p= 0.012).&#x0D; Conclusion: Stethoscope guided technique for inflation of ETT cuff is more effective in reducing frequency of post operative sore throat.

Endotracheal Tube Cuff Pressure Management: An Observational Study Guided by the SEIPS Model.

The aim of the rigorous endotracheal tube cuff pressure (ETTCP) management is to maintain cuff pressures within the recommended values during the mechanical ventilation period. However, hyperinflation or hypoinflation of cuff has been reported because of inconsistent clinical practices in intensive care unit (ICU) settings. Furthermore, there is no available best evidence for clinical decision-making regarding the ETTCP management provided by international institutes. The aim of this study was to examine the ETTCP management work system in ICU settings in urban hospitals of Turkey and the United States using the Systems Engineering Initiative for Patient Safety model. This was a direct observational, prospective field study, in which the COREQ (Consolidated Criteria for Reporting Qualitative Research) tool was used. The direct observations and follow-up interviews were conducted, and the results were reported using the Systems Engineering Initiative for Patient Safety model. We identified important characteristics of the ETTCP management work system in each of the 4 ICU and differences across the settings. Common use of the evidence-based and internationally used protocols may standardize the management of ETTCP, improve communication among ICU staff, and promote desired patient outcomes. There is a need for developing strategies to provide standardized ETTCP management and to improve patient's quality of care. To improve the patient outcomes and quality of care, ICU managers should consider clear expectations for ETTCP management in each job description, structured and evidence-based protocols, and effective communication among disciplines and provide teaching opportunities to encourage physicians, nurses, and respiratory therapists to meet their educational needs.

Abstract No.: ABS1770: Cuffed versus uncuffed endotracheal tubes in infants undergoing elective surgery in prone position:peritubal leak at standardised ventilator settings

Background & Aims:The purpose of this study was to compare peritubal leak in cuffed and uncuffed tubes in infants at standardised ventilatorsettings. Secondary objective was to see incidence of accidental extubation and postoperative respiratory complications such as stridor and sore throat.Methods:With ethics committee approval, a prospective,randomised,clinical study was conducted. Patients aged between birth to 1 year, American Society of Anesthesiologists ASA grade I,II and III, requiring general anaesthesia with orotracheal intubation in prone position during elective surgery were included and children with parents not giving consent,children with airway anomaly, laparoscopic surgery, and emergency surgery were excluded. Tracheal tube size was judged as adequate if the leak pressure was 20 cm H2O or less. Tube was exchanged to next larger size if the leak pressure was too high and tube size was exchanged to next smaller size, when cuff pressure exceeded 20 cm H2O.Results:60 infants were studied.In group 1 in which cuffed tube was used, there were no leaks,on the other hand, in group 2,17 out of 30 patients had peritubal leak and tube was exchanged to next larger size uncuffed tube, p value was <0.001. Moreover, the incidenceof accidental extubation, post extubation sore throat and stridor was more in uncuffed group, It was 2/6/6 in uncuffed group and 0/3/4 in cuffed group respectively. Tracheal tube exchange rate was also higher in uncuffed group.Conclusion:We found that in microcuff paediatric endotracheal tube, there is less peritubal leak; selection of cuffed tube with small internal diameter compared to uncuffed tubes implicates a higher chance for adequate fit of the tube at cricoid ring and due to this there is least chance of accidental extubation in the prone position.Peritubal leakGroup I (n=30)Group II (n=30)Total (n=60) No.%No.%No.%Absent30100.01343.34371.7Present00.01756.71728.3

Abstract No.: ABS1132: A Comparative study of Oropharyngeal leak pressure in LMA ProtectorTM with cuff pilot vs LMA SupremeTM in paralysed patients: A prospective randomised clinical study.

Background & Aims:Oropharyngeal leak pressure (OLP) is the pressure at which a gas leaks around the airway, higher leak pressures, betterseal. Our primary aim was to measure OLP and Secondary aims were to measure Insertion Time, Numbers of Attempts,Ease of Insertion, and Postoperative complications.Methods:The study was carried out in 62 adult patients of ASA I & II which were randomized into 2 groups Group S (LMA SupremeTM) and Group P (LMA ProtectorTM) (n = 31 each) based on a computer‑generated random sequence table.Respective LMA’s were inserted after general anaesthesia induction and OLP were measured at cuff pressure of 60 cmH2O in each group accordingly. Secondary Parameters such as insertion time, no of attempts of supraglottic airway devicesand gastric tube, ease of insertion were measured. Intraoperative haemodynamic parameters and postoperatively airwaymorbidity were also measured.Results:OLP were significantly higher (P<0.0001) for LMA Protectorâ„¢ compared to LMA Supremeâ„¢.The OLP in LMAProtectorâ„¢ group was 28.12 cmH2O (SD- 1.96) compared to 21.5 cmH2O (SD- 2.65) in LMA Supremeâ„¢ group. Insertiontime was significantly higher for the LMA Protectorâ„¢ (24.58 sec) compared to the LMA Supremeâ„¢ (16.67 sec) (P<0.0001). There were no statistically significant differences in ease of insertion, Numbers of Attempts, trauma, sorethroat, Dysphagia and Dysphonia.Conclusion:Oropharyngeal leak pressures were consistently higher (>5 cm H2O) for LMA Protectorâ„¢ compared to LMA Supremeâ„¢, Thus providing effective ventilation than LMA SupremeTM .

Comparison between Endotracheal Tube Cuff Pressure Measurements Before and After nursing Interventions among Mechanically Ventilated Patients

Comparison between Endotracheal Tube Cuff Pressure Measurements Before and After nursing Interventions among Mechanically Ventilated Patients

Sealing mechanism study of laryngeal mask airways via 3D modelling and finite element analysis

Proper sealing of laryngeal mask airways (LMAs) is critical for airway management in clinical use. Understanding the sealing mechanism can significantly help front-line anaesthetists to reduce the incidence of adverse events. However, anaesthetists, who may not have the most substantial engineering backgrounds, lack intuitive ways to develop an understanding of the LMA sealing mechanism effectively. The paper aims to study the LMA-pharynx sealing mechanisms from the perspective of front-line anaesthetists. We use a computer-aided 3D modelling technique to visualise the LMA—pharynx interactions, which helps anaesthetists identify the critical areas of complications. Furthermore, we conduct a quantitative pressure distribution analysis of the LMA-pharynx contacting surface using the finite element analysis technique, which helps further understand the sealing mechanics in those areas. We present two cases studies based on one male volunteer, aged 50, inserted with a ProSeal LMA. In the first case, a relatively low cuff pressure (CP) was applied to simulate the clinical circumstances in which complications related to air leakage are most likely to happen; in the second case, we increase the CP to a relatively high value to simulate the scenarios with an increased risk of complications related to high mucosal pressure. The experiments suggest the follows: (1) Sore throat complications related to high mucosal pressure is most likely to occur in the hypopharynx with a high CP setting, particularly in the areas where the cricoid cartilage presses the mucosa. (2) The narrow hyoid bone super horn width likely causes LMA insertion difficulties. (3) Insufficient CP will significantly increase the risk of air leakage in the oropharynx. A complete sealing pressure line in the contacting surface will be formed with sufficient CP, thereby preventing the air leakage into the oral.

Tracking Peripheral Artery Motion and Vascular Resistance With a Multimodal Wearable Sensor Under Pressure Perturbations.

The status of peripheral arteries is known to be a key physiological indicator of the body's response to both acute and chronic medical conditions. In this paper, peripheral artery deformation is tracked by wearable photoplethysmograph (PPG) and piezo-electric (polyvinylidene difluoride, PVDF) sensors, under pressure-varying cuff. A simple mechanical model for the local artery and intervening tissue captures broad features present in the PPG and PVDF signals on multiple swine subjects, with respect to varying cuff pressure. These behaviors provide insight into the robustness of cardiovascular property identification by noninvasive wearable sensing. This is found to help refine noninvasive blood pressure measurements and estimation of systemic vascular resistance (SVR) using selected features of sensor amplitude versus applied pressure.