Cuff Pressure Research Articles

ENDOTRACHEAL TUBE CUFF PRESSURE CONTROL DURING ANESTHESIA
 IN CANCER PATIENTS

Relevance: An endotracheal tube (ETT) cuff provides a seal and encloses the lower airway from aspiration. Normally, the pressure in the
 ETT cuff is in the range of 20 to 30 cm of water column. Both increased and insufficient inflation of the ETT cuff is associated with a number of
 complications.
 The purpose of the research: comparison of palpation and apparatus methods of pressure control in the cuff of the endotracheal tube during
 anesthesia in cancer patients.
 Methods: A prospective observational study included 60 patients during general anesthesia in the department of anesthesiology and intensive
 care of KazIOR. Air was injected into the ETT cuff using a syringe, followed by palpation of the ETT cuff balloon and pressure control using the
 IntelliCuff device (Hamilton Medical, Switzerland). The actual pressure was compared with normal values, then the volume of air, actual and necessary to achieve normal pressure, was estimated.
 Results: assessment of the pressure level by the “classic” palpation method led to errors in the pressure level in the ETT cuff in more than 50%
 of cases; the normal level of pressure was only in 25 patients (42%), while the measured air volume in the cuff was on average 5.9±1.9 ml, although
 for the average air volume to achieve a pressure of 25 mm of water column was 3.9 ml, which led to an overestimated level of pressure in the ETT cuff.
 Conclusion: Determining ETT cuff pressure by palpation of the control balloon, while common practice, often results in incorrect pressure
 readings. At the same time, both high and low pressure in the ETT cuff are associated with the development of complications. The use of devices
 for measuring pressure in the ETT cuff allows you to control its level, while devices that allow prolonged monitoring of pressure in the ETT cuff
 have an advantage

Evaluation of Regional Myocardial Work Indices in Pediatric Essential and Renal or Renovascular Hypertension.

Myocardial work (MW) is an index of LV function based on pressure-strain loops and brachial cuff pressure measurement. MW has been proposed as more sensitive than conventional functional parameters, as it accounts for afterload and myocardial deformation. However, many studies have been limited to assessment of global MW indices, neglecting regional differences in cardiac associated with hypertension and consequent cardiac remodeling. We aimed to quantify regional MW in pediatric hypertension and compare the findings in renal or renovascular hypertension (RHTN) with essential hypertension (EHTN). We retrospectively assessed conventional markers of LV function, and both global and regional MW indices in 78 patients (49 males, 15.4 ± 2.94 years) with EHTN and RHTN. Peak systolic strain (PSS) in the basal septal segment was significantly impaired in patients with RHTN compared to EHTN (-13.00% [-15.50%; -13.00%] vs. -15.00% [-17.50%; -13.50%], P = 0.034). Similarly, basal septal MW indices were significantly elevated in patients with EHTN compared to RHTN, including MW efficiency (MWE) (95.0% [93.0%; 98.0%] vs. 94.0% [89.0%; 95.0%], P = 0.004) and constructive work (CW) (1700 mm Hg% (409 mm Hg%) vs. 1520 mm Hg% (336 mm Hg%), P = 0.037). Wasted work (WW) was significantly elevated in the RHTN group (79.0 mm Hg% [28.5 mm Hg%; 104 mm Hg%] vs. 105 mm Hg% [62.0 mm Hg%; 164 mm Hg%], P = 0.010). Significant differences in basal septal PSS and MW indices were observed between EHTN and RHTN. These findings highlight the usefulness of regional MW indices in assessing disease and may help differentiate between etiologies of pediatric hypertension.

Acute physiological responses to steady-state arm cycling ergometry with and without blood flow restriction.

To compare heart rate (HR), oxygen consumption (VO2), blood lactate (BL), and ratings of perceived exertion (RPE) during arm cycling with and without a blood flow restriction (BFR). Twelve healthy males (age: 23.9 ± 3.75years) completed four, randomized, 15-min arm cycling conditions: high-workload (HW: 60% maximal power output), low-workload (LW: 30% maximal power output), low-workload with BFR (LW-BFR), and BFR with no exercise (BFR-only). In the BFR conditions, cuff pressure to the proximal biceps brachii was set to 70% of occlusion pressure. HR, VO2, and RPE were recorded throughout the exercise, and BL was measured before, immediately after, and five minutes post-exercise. Within-subject repeated-measures ANOVA was used to evaluate condition-by-time interactions. HW elicited the greatest responses in HR (91% of peak; 163.3 ± 15.8bpm), VO2 (71% of peak; 24.0 ± 3.7mlkg-1min-1), BL (7.7 ± 2.5mmol L-1), and RPE (14 ± 1.7) and was significantly different from the other conditions (p < 0.01). The LW and LW-BFR conditions did not differ from each other in HR, VO2, BL, and RPE mean of conditions: ~ 68%, 41%, 3.5 ± 1.6mmol L-1, 10.4 ± 1.6, respectively; p > 0.05). During the BFR-only condition, HR increased from baseline by ~ 15% (on average) (p < 0.01) without any changes in VO2, BL, and RPE (p > 0.05). HW arm cycling elicited the largest and most persistent physiological responses compared to LW arm cycling with and without a BFR. As such, practitioners who prescribe arm cycling for their clients should be advised to augment the demands of exercise via increases in exercise intensity (i.e., power output), rather than by adding BFR.

Impact of compression on velocity of venous and arterial main blood flow and cutaneous microcirculation of the lower extremity

Objective. To study the impact of compression on velocity of venous and arterial main blood flow of the lower extremity, as well as cutaneous microcirculation in the back part of the foot in healthy individuals and patients with decompensated forms of varicose disease and postthrombophlebitis syndrome.&#x0D; Materials and methods. In the investigation 56 individuals took part and divided into three groups: Group I – 20 healthy persons; Group II – 15 patients with varicose disease in decompensated stage; Group III– 21 patients with decompensated stage of postthrombophlebitis syndrome.&#x0D; In all participants of the investigation the index of ankle–brachial pressure, deep–femoro–popliteal index, the regional perfusion index, transcutaneous partial pressure of oxygen and partial pressure of carbon dioxide, the arterial blood flow velocity in femoral artery and of venous blood flow distally from sapheno–femoral junction were measured before and after application of elastic medical knitwear of various Class of compression or the cuff pressure.&#x0D; Results. In the Class III compression in patients of Group III the transcutaneously registered indices crossing have occurred between partial pressure of oxygen and carbon dioxide, accompanied by domination of the carbon dioxide partial pressure over the oxygen partial pressure while further enhancement of the compression Class. In patients of Group II this tendency was observed while application of Class IV compression only. At the investigation beginning the values of partial pressure of carbon dioxide registered were higher in the Group III patients, than in the patients of Group II (p=0.0001).&#x0D; Conclusion. While application of the Class III compression the velocity of the hip venous blood flow, comparing with its initial values, have lowered at average by 78% in patients of Group II and at average in 7.4 times in the patients of |Group III (p=0.0001). It is affordable in patients, suffering decompensated postthrombophlebitic syndrome, to apply the elastic compression of Classes I–II, while in those, having varicose disease in decompensated stage, – the elastic compression of Classes III and iV as well.

Tracheal tube cuff pressure during anesthesia for robotic-assisted laparoscopic prostatectomy and the efficacy of an automatic cuff pressure controller (SmartCuff): observational studies of 1-sample paired data.

The cuff pressure of a tracheal tube may increase during robot-assisted laparoscopic surgery for prostatectomy (RALP), which requires pneumoperitoneum in a steep head-down position, but there have been no studies which confirmed this. In study 1, we studied how frequently the cuff pressure significantly increased during anesthesia for the RALP. In study 2, we studied if the SmartCuff (Smiths Medical Japan, Tokyo) automatic cuff pressure controller would minimize the changes in the intracuff pressure. With approval of the study by the research ethics committee (approved number: 20115), we measured the cuff pressures in anesthetized patients undergoing RALP and in those undergoing gynecological laparotomy (as a reference cohort), with and without the use of the SmartCuff. In 21 patients undergoing RALP, a clinically meaningful increase (5 cmH2O or greater) was observed in all the 21 patients (P = 0.00; 95% CI for difference: 86-100%), whereas in 23 patients undergoing gynecological laparotomy, a clinically meaningful decrease (5 cmH2O or greater) was observed in 21 of 23 patients (91%, P < 0.0001; 95% CI for difference: 72-99%). With the use of the SmartCuff, there was no significant increase in the incidence of a clinically meaningful change in the intracuff pressure in either cohort. The cuff pressure of a tracheal tube would frequently increase markedly in patients undergoing RALP, whereas it would frequently decrease markedly in patients undergoing gynecological laparotomy. The SmartCuff may inhibit the changes in the cuff pressure during anesthesia.

1115 NON-INVASIVE MYOCARDIAL WORK INDICES IN PATIENTS WITH FONTAN CIRCULATION

Abstract Background Although the Fontan operation has contributed greatly to the improvement of survival in patients with a single ventricle, cardiac function and exercise capacity may deteriorate over time. However, there have been no quantitative analyses of the effects of Fontan circulation on myocardial work (MW). Recently, a novel non-invasive method for calculating MW has been introduced on the basis of speckle tracking analysis with the estimation of left ventricular (LV) pressure from brachial artery cuff pressure. Purpose Aim of this study was to evaluate the diagnostic performance of the non-invasive myocardial work indices in predicting subclinical myocardial work impairment in Fontan patients. Methods A total of 69 patients were included and compared with healthy age- and sex- matched controls (CTRL). Ventricular systolic function and global longitudinal strain (GLS) were assessed. Cardiopulmonary exercise test was performed. Global myocardial work index (MWI) was calculated as the area of the LV pressure strain loops. From MWI, global constructive work (MCW), wasted work (MWW) and work efficiency (MWE) were estimated. Results The two groups were comparable for blood pressure, weight and height. Mean age of Fontan patients was 21.0±9.2 years. MWI (1162 ± 364 mmHg% vs 1777 ± 240 mmHg%, p &amp;lt; 0.001), MCW (1554 ± 450 mmHg% vs 2102 ± 221 mmHg%, p = 0.001) and MWE (90 ± 6% vs 96 ± 2% p = 0.001) were significantly reduced in Fontan patients compared with healthy CTRL. Moreover, GLS (-13,9 ± 3,1% vs -21,2 ± 1.5%, p &amp;lt; 0.001) and the ejection fraction (EF) (58,9 ± 4.5% vs 63.3 ± 3.9%, p &amp;lt; 0.002) were significantly lower in Fontan patients. Fontan patients with normal EF showed, however, significantly reduced values of MWI compared with CTRL (p&amp;lt;0.05). Fontan patients with functional right ventricle showed significantly reduced MWE compared with patients with functional left ventricle (p=0.030). In univariate analysis, peak VO2 was significantly associated with age, SatO2, MWI. In multivariate regression, lower peak VO2 was associated with older age (p = 0.003) and lower MWI (p = 0.026). Conclusions Fontan physiology is associated with disadvantageous ventricular work. In Fontan patients, estimation of MWI may be a more sensitive indicator of myocardial work impairment compared with EF and is able to predict exercise capacity.

Effects of Sex and Cuff Pressure on Physiological Responses during Blood Flow Restriction Resistance Exercise in Young Adults.

The purpose of this study was to examine the physiological responses resulting from an acute blood flow restriction resistance exercise bout with two different cuff pressures in young, healthy men and women. Thirty adults (18-30 yr) completed a bilateral leg extension blood flow restriction bout consisting of four sets (30-15-15-15 repetitions), with cuffs applied at pressures corresponding to 40% and 60% of the minimum arterial occlusion pressure (AOP) needed to completely collapse the femoral arteries. During each of these conditions (40% and 60% AOP), physiological measures of near-infrared spectroscopy (NIRS) and EMG amplitude (EMG AMP) were collected from the dominant or nondominant vastus lateralis. After each set, ratings of perceived exertion (RPE) were collected, whereas only at baseline and at the end of the bout, mean arterial pressure (MAP) was assessed. Separate mixed-factorial ANOVA models were used to examine mean differences in the change in EMG AMP and NIRS parameters during each set. The absolute RPE and MAP values were also examined with separate ANOVAs. A P value ≤0.05 was considered statistically significant. Regardless of sex or cuff pressure, the change in EMG AMP was lower in set 1 (14.8%) compared with the remaining sets (22.6%-27.0%). The 40% AOP condition elicited the greatest changes in oxy[heme] and deoxy[heme], while also providing lower RPEs. For MAP, there was an effect for time such that MAP increased from preexercise (87.5 ± 4.3 mm Hg) to postexercise (104.5 ± 4.1 mm Hg). The major findings suggested that the 40% AOP condition permitted the greatest amount of recovery during the interset rest. In addition, there did not seem to be any meaningful sex-related difference in this sample of young healthy adults.

Effects of Low-Load Blood Flow Restriction Resistance Training on Muscle Strength and Hypertrophy Compared with Traditional Resistance Training in Healthy Adults Older Than 60 Years: Systematic Review and Meta-Analysis.

There is clinical interest in determining the effects of low-load blood flow restriction (LL-BFR) resistance training on muscle strength and hypertrophy compared with traditional high- and low-load (HL and LL) resistance training in healthy older adults and the influence of LL-BFR training cuff-pressure on these outcomes. A search was performed on the MEDLINE, PEDro, CINHAL, Web of Science, Science Direct, Scopus, and CENTRAL databases. The analysis included 14 studies. HL resistance training produces a small increase in muscle strength (eight studies; SMD, -0.23 [-0.41; -0.05]) but not in muscle hypertrophy (six studies; (SMD, 0.08 [-0.22; 0.38]) when compared with LL-BFR resistance training. Compared with traditional LL resistance training, LL-BFR resistance training produces small-moderate increases in muscle strength (seven studies; SMD, 0.44 [0.28; 0.60]) and hypertrophy (two studies; SMD, 0.51 [0.06; 0.96]). There were greater improvements in muscle strength when higher cuff pressures were applied versus traditional LL resistance training but not versus HL resistance training. LL-BFR resistance training results in lower muscle strength gains than HL resistance training and greater than traditional LL resistance training in healthy adults older than 60 years. LL-BFR resistance training promotes a similar muscle hypertrophy to HL resistance training but is greater than that of traditional LL resistance training. Applying cuff pressures above the limb occlusion pressure could enhance the increases in muscle strength compared with traditional LL resistance training.

Tracheo-oesophageal fistula - A disastrous complication of endotracheal intubation!

A 28-year old man required invasive mechanical ventilation in view of organophosphorus poisoning in a peripheral hospital. His trachea was extubated ten days later following which he presented with dysphagia, voice change, burping, fever and cough. He was referred to our hospital for further management. His barium swallow radiograph showed a large tracheo-oesophageal fistula. Therefore, he was scheduled for oesophageal transection and colonic transposition. Following induction of anaesthesia, despite easy laryngoscopy view (Cormack Lehane grade 1), the tracheal intubation was found to be difficult as the tube tended to pass through the fistula into the oesophagus repeatedly as confirmed by absence of capnogram trace. Attempts to bypass the fistula using a fibreoptic scope and even a double lumen tube also failed. Identification of oesophageal intubation would have been missed or possibly detected late in this case with disastrous consequences but for absence of capnogram. Finally, the tracheal tube was successfully negotiated beyond the fistula with the help of a gum elastic bougie directed anteriorly into the trachea and a good capnogram was obtained. The surgery was uneventful and the trachea was extubated 24 h later in the intensive care unit following which the patient developed stridor requiring permanent tracheostomy. This case report illustrates the novel use for gum elastic bougie during tracheal intubation. This also highlights the importance of repeated measurement of tracheal cuff pressure in patients especially those receiving long duration mechanical ventilation.

Changes of oscillogram envelope maximum with blood pressure and aging: a quantitative observation

Objective. The oscillometric blood pressure (BP) measurement technique estimates BPs from analyzing the oscillometric cuff pressure waveform (oscillogram) envelope. The oscillogram envelope maximum is associated with physiological changes and influences BP measurement accuracy. We aim to quantitatively investigate the effect of BP and aging on the changes of oscillogram envelope maximum. Approach. Four hundred and sixty-two subjects (214 female, 248 male) were recruited. The cuff pressure was digitally recorded during linear cuff deflation to derive oscillogram envelopes and their maximums. Moderation analysis was performed to investigate whether the relationship between BP and envelope maximum was moderated by age. Subjects were divided into five age categories and three BP groups. The envelope maximums were compared between different BP and age categories to qualify their changes with increased BP and aging. Main results. Age has a significant moderating effect on the relationship between BP and envelope maximum (P < 0.05). The oscillogram envelope maximums increased significantly with increased BPs (P < 0.05 between each BP groups) and aging (P < 0.05 for > 60 years old groups in comparison with younger groups). Significance. This study experientially and theoretically concluded the BPs and aging are two important factors that influence the maximum value of the oscillogram envelope.

A Comparison between High and Low Cuff Pressures on Muscle Oxygen Saturation and Recovery Responses Following Blood-Flow Restriction Resistance Exercise.

The aim of the study was to compare the recovery response and muscle oxygenation of a blood-flow restriction resistance exercise (BFR) session with high [HP: 80% of the arterial occlusion pressure (AOP)] and low cuff pressure (LP: 40% of AOP). Both exercise sessions included 4 sets to failure at the barbell preacher curl exercise. Twelve resistance trained men (27.4 ± 5.0 years; 83.5 ± 11.6 kg; 176.6 ± 7.0 cm) performed each protocol in a counterbalanced, randomized order. Maximal isometric force, muscle morphology and muscle soreness of the biceps brachii muscle were assessed at baseline, 15-min, 60-min and 24-h post each testing session. In addition, muscle oxygen saturation (SmO2) was assessed during each training session. A lower number of repetitions (p = 0.013) was detected in HP compared to LP. A lower SmO2 (p < 0.001) was detected in the recovery time between the sets in HP (mean: 47.6 ± 15.7%) compared to LP (mean: 68.9 ± 7.2%). No differences between the two trials (p > 0.05) were noted for isometric force, muscle architecture and soreness at any timepoint. Results indicate that, despite a high cuff pressure may induce a more hypoxic condition compared to a lower cuff pressure, recovery responses may not be affected.

Airway management with novel intubating laryngeal tubes has no influence on cerebral oxygenation in cardiac surgery patients: A prospective observational study

BackgroundA laryngeal tube is often used as an alternative to intubation with direct laryngoscopy during cardiopulmonary resuscitation. However, in a study with piglets undergoing simulated cardiac arrest, reduced carotid artery blood flow was associated with the insertion of different supraglottic airway devices, such as a laryngeal tube. Limited by its construction, secondary tracheal intubation through a laryngeal tube was difficult or impossible in contrast to a second generation laryngeal mask. The new disposable intubating laryngeal tube with suction (iLTS-D®) seems to facilitate tracheal intubation. We hypothesized that iLTS-D, when inflated to the recommended air volume, does not reduce cerebral oxygenation in patients with cardiovascular diseases undergoing elective cardiac surgery.MethodsThis single-center prospective, controlled observational study was approved by the local ethics committee (Ethical Committee No. 2018-13716). Forty adult patients undergoing elective cardiac surgery requiring tracheal intubation were included in this study. The exclusion criteria were age &amp;lt;18 years and a high risk of aspiration, inability to consent, height &amp;lt;155 cm, or pregnancy. Prior to insufflation and deflation of the cuffs, we performed cerebral oximetry via near-infrared spectroscopy. The primary outcome was a significant reduction in NIRS in the context of the preinduction baseline value after inflation of the cuffs with the recommended air volume, defined as a ≥25% decrease from baseline or an absolute value ≤ 50%. The secondary endpoints were differences in time points, insertion success rates, and complications.ResultsThere was no significant reduction in cerebral oximetry after inflation with the recommended cuff volume and an initially measured cuff pressure of &amp;gt;120 cmH2O. Overall, tracheal intubation was achieved in a median of 20 s [interquartile range 15-23 s] and enabled sufficient ventilation and tracheal intubation through the iLTS-D in all patients. Traces of blood on the cuffs (after removing the iLTS-D) and a sore throat (evaluated 2 h after removing the tracheal tube) were observed in one patient.ConclusionOur results showed no association between the insertion of the iLTS-D and reduced cerebral oxygenation in patients undergoing elective cardiac surgery.Trial registrationClinicalTrials.gov, NCT03942809.

An Investigation into Design of Blood Pressure Cuffs Using the Tekscan Pressure Sensing System

Cuff design is the most important aspect to work on for the accurate measurement of blood pressure. For the very first time, pressure distribution underneath different parts/components of the fabric cuffs was analysed in detail using an advanced interface pressure sensing system. The pressure distribution at the interface of the selected cuffs and an arm simulator were measured experimentally while simulating blood pressure measurement. Fabrics are the main cuff constructing material and a relationship was found between cuff fabric properties and pressure at the interface of the cuff and the arm simulator. It was also found that the pressure distribution under different parts of the same cuff varied due to the uneven contact of the cuff fabric with the arm simulator. Components attached to cuff fabric which facilitate blood pressure measurement either confine or drive fabric according to their size and placement; they may cause non-uniform interface pressure distribution on the human arm too. It was also examined whether the selected cuffs were applying higher or lower average pressure over the surface of the simulator and the range varied from 8 mmHg to 25 mmHg. This indicates that the subsequent pressure distribution inside the arm tissues and over an artery would also vary further due to the cuffs being of different designs. This study found that cuffs would be unable to transfer the required pressure over the artery to block blood flow as and when needed.

Automated model calibration with parallel MCMC: Applications for a cardiovascular system model.

Computational physiological models continue to increase in complexity, however, the task of efficiently calibrating the model to available clinical data remains a significant challenge. One part of this challenge is associated with long calibration times, which present a barrier for the routine application of model-based prediction in clinical practice. Another aspect of this challenge is the limited available data for the unique calibration of complex models. Therefore, to calibrate a patient-specific model, it may be beneficial to verify that task-specific model predictions have acceptable uncertainty, rather than requiring all parameters to be uniquely identified. We have developed a pipeline that reduces the set of fitting parameters to make them structurally identifiable and to improve the efficiency of a subsequent Markov Chain Monte Carlo (MCMC) analysis. MCMC was used to find the optimal parameter values and to determine the confidence interval of a task-specific prediction. This approach was demonstrated on numerical experiments where a lumped parameter model of the cardiovascular system was calibrated to brachial artery cuff pressure, echocardiogram volume measurements, and synthetic cerebral blood flow data that approximates what can be obtained from 4D-flow MRI data. This pipeline provides a cerebral arterial pressure prediction that may be useful for determining the risk of hemorrhagic stroke. For a set of three patients, this pipeline successfully reduced the parameter set of a cardiovascular system model from 12 parameters to 8-10 structurally identifiable parameters. This enabled a significant efficiency improvement in determining confidence intervals on predictions of pressure compared to performing a naive MCMC analysis with the full parameter set. This demonstrates the potential that the proposed pipeline has in helping address one of the key challenges preventing clinical application of such models. Additionally, for each patient, the MCMC approach yielded a 95% confidence interval on systolic blood pressure prediction in the middle cerebral artery smaller than ±10mmHg (±1.3kPa). The proposed pipeline exploits available high-performance computing parallelism to allow straightforward automation for general models and arbitrary data sets, enabling automated calibration of a parameter set that is specific to the available clinical data with minimal user interaction.

Methods Used for Endotracheal Tube Cuff Inflation and Pressure Verification in Veterinary Medicine: A Questionnaire on Current Practice.

Endotracheal intubation is a routine procedure in veterinary anaesthesia, yet no consensus guidelines exist for endotracheal tube (ETT) cuff inflation and pressure measurement. The aim of this study was to assess current practice of ETT cuff inflation and seal verification in veterinary medicine. An online questionnaire was distributed among veterinary professionals who administer anaesthesia, comprising six demographic and twelve ETT cuff-related questions per species. N = 348 questionnaires were completed. Cuff pressure was measured by 30% of respondents in cats, 32% in dogs and 9% in both farm animals and horses. Anaesthesia diplomates were not more likely to measure cuff pressure than others, except in cats (OR: 1.8; 95% CI: 1.1-2.9). The most frequently selected recommended range of cuff pressure was 20-30 cm H2O, regardless of species, although &gt;30 cm H2O was selected significantly more often in horses compared to dogs, cats and farm animals. The preferred technique to verify cuff seal was minimal occlusive volume in dogs, cats and farm animals, whereas in horses, the preferred method was verification of normal capnogram waveform. ETT cuff pressure measurement remains uncommon in veterinary anaesthesia. The development of consensus recommendations for cuff inflation, including evidence-based target cuff pressure ranges for various species and different ETT models or materials, can help to improve practice.

Effect on Cuff Pressure of Various Endotracheal Tube Cuff Inflation Methods

Objective: To compare mean endotracheal tube cuff pressures generated using two endotracheal tube cuff inflation methods;just-Seal versus Stethoscope-Guided in patients undergoing elective surgery under general Anaesthesia.&#x0D; Study Design: Quasi-experimental study.&#x0D; Place and Duration of Study: Anesthesia Department, Combined Military Hospital, Rawalpindi Pakistan, from Jan to Jul 2021.&#x0D; Methodology: A total of 100 patients undergoing elective surgery under general endotracheal tube anaesthesia between 18–60 years of age of either gender were included. Patients were equally allocated (n=50 each) to two Groups, A (Just Seal Group) and B (Stethoscope Guided Group). In the Group-A method, the air was injected until no air leak could be heard. The pressure was measured using a “Portex cuff pressure manometer”. In the Group-B method, a stethoscope bell was placed on the thyroid lamina, and harsh breath sounds were auscultated during ventilation. Cuff was inflated till the sounds changed to smooth sounds. The pressure was measured and then noted down. &#x0D; Results: Among 100 patients, 39 % were males, and 61 % were females. The mean endotracheal cuff pressure in Group-A was 39.90±3.19 centimetres of water and 28.42±3.52 centimetres of water, with Group-B (p-value of 0.001).&#x0D; Conclusion: Post-intubation cuff pressure measured in patients undergoing elective surgery under general anaesthesia of the just seal group is higher than that in the stethoscope-guided group.&#x0D; Keywords: Cuff pressure, Stethoscope-guided, Tracheal intubation.&#x0D;

Pressure changes in tapered and cylindrical shaped cuff after extension of head and neck: A randomized controlled trial.

The proper cuff pressure of endotracheal tube (ET) plays an important role in sealing the airway and preventing airway complications during mechanical ventilation. The ET cuff shape affects the cuff pressure after positional change. To investigate cuff pressure between tapered and cylindrical cuff after extension of head and neck during nasal endotracheal intubation. In a randomized clinical trial, 52 patients were randomized to one of two groups: cylindrical cuff or Tapered cuff. Cuff pressure with 22 cmH2O was applied to patients in the neutral position. After extension of head and neck, the cuff pressure was evaluated again and readjusted to 22 cmH2O. In addition, the extent of cephalad migration of ET tip was assessed and postoperative airway complications such as sore throat, and hoarseness were measured. The cuff pressure was higher in the tapered cuff (28.7 ± 1.0 cmH2O) than in the cylindrical cuff (25.5 ± 0.8 cmH2O) after head and neck extension (P < 0.001). The extent of cephalad migration of tube tip was greater in TaperGuard ET (18.4 ± 2.2 mm) than in conventional ET (15.1 ± 1.2 mm) (P < 0.001). The incidence of postoperative airway complications was comparable between two groups. After head and neck extension, the cuff pressure and the extent of cephalad migration of ET was greater in tapered cuff than in cylindrical cuff during nasal intubation, respectively.

Use of an innovative cuff pressure control and subglottic secretions drainage system in COVID-19 ARDS patients undergoing pronation

We conducted a proof of concept study where Anapnoguard endotracheal tubes and its control unit were used in 15 patients with COVID-19 acute respiratory distress syndrome. Anapnoguard system provides suction, venting, rinsing of subglottic space and controls cuff pressure detecting air leakage through the cuff. Alpha-amylase and pepsin levels, as oropharyngeal and gastric microaspiration markers, were assessed from 85 tracheal aspirates in the first 72 h after connection to the system. Oropharyngeal microaspiration occurred in 47 cases (55%). Episodes of gastric microaspiration were not detected. Patient positioning, either prone or supine, did not affect alpha-amylase and pepsin concentration in tracheal secretions. Ventilator-associated pneumonia (VAP) rate was 40%. The use of the AG system provided effective cuff pressure control and subglottic secretions drainage. Despite this, no reduction in the incidence of VAP has been demonstrated, compared to data reported in the current COVID-19 literature. The value of this new technology is worth of being evaluated for the prevention of ventilator-associated respiratory tract infections.

Comparing the Immediate Effect of Pneumatic and Conventional Knee Braces on Gait, Satisfaction and Pain in Patients With Knee Medial Osteoarthritis

Background/Aims Knee braces can change loading direction on knees in people with osteoarthritis, thereby reducing symptoms and progression of the disease. The aims of this study were to explore the immediate effect of two types of braces, a pneumatic knee brace with air pressure embedded in a sandal cuff (sandal cuff pressure) and a conventional knee brace on gait, pain and satisfaction during walking in patients with knee medial osteoarthritis. Methods A total of 28 patients with knee medial osteoarthritis were assigned to two groups, 14 patients used a conventional brace and 14 used a prototype brace with a pneumatic system, which was designed and fabricated by the authors, and followed the mechanism of variable pressures in the stance and swing phases of a gait cycle in a patient’s knee. The gait parameters (walking self-selected speed, cadence, stride length, knee range of motion, and maximum knee adduction moment) were measured with a Kistler force plate and Vicon motion analysis under two conditions: with and without brace for the conventional brace group, and under three conditions of no brace, brace with sandal cuff pressure, and brace without sandal cuff pressure for the pneumatic brace group. Patients’ pain and satisfaction were also measured using a visual analogue scale and Likert scale respectively. Results Both groups showed a significant reduction in maximum knee adduction moment and pain wearing braces in comparison to no brace during walking (P&lt;0.05). The knee range of motion was significantly decreased in the pneumatic brace group with and without sandal cuff pressure compared with no brace (P&lt;0.001). No significant difference was found for any of the variables when using the pneumatic brace with and without sandal cuff pressure (P&gt;0.05). In the between-group comparison, only patients’ satisfaction was significantly reduced when using the pneumatic brace in both walking with (P=0.041) and without (P=0.02) sandal cuff pressure compared to those using the conventional brace. Conclusions Both conventional and pneumatic braces led to reduced knee adduction moment and pain in patients with knee osteoarthritis. However, using a pneumatic brace reduced the knee range of motion and satisfaction of patients, which could be because the brace was a prototype.

Endotracheal Tube Cuff Pressures in the Operating Room of a Pediatric Hospital: A Quality Improvement Initiative.

Four plan-do-study-act (PDSA) cycles were completed in the operating rooms at Nationwide Children's Hospital over 9 months to assess ways to improve the accuracy of obtaining recommended ETT cuff pressures. Control charts were used to evaluate the primary outcome measure. Preimplementation, ETT cuff pressures were out of the recommended range 76% of the time. Cuff pressures were out of the recommended range 64% of the time with the addition of the air method, 84% of the time in the tidal volume ratio cycle, and 50% of the time using the removal of air technique. The removal of air method was the most effective in achieving cuff pressures within the recommended pressure range (P < 0.001). Using quality improvement methodology, the percentage of ETT cuff pressures falling within the recommended pressure range increased using the removal of air technique. This approach is a simple and practical method that can be easily implemented in the clinical setting and would provide additional safety in the anesthetic management of pediatric patients.