Cuff Volume Research Articles

The evaluation of endotracheal tube cuff pressure in pediatric patients by subjective inflation techniques: a prospective observational study.

Cuffed endotracheal tubes (ETTs) are commonly used in pediatric patients, with the gold standard for measuring cuff pressure being a cuff pressure manometer. However, this equipment is not always available in every operating room. Subjective inflation techniques, such as the minimal occluding volume (MOV) technique and the stethoscope-guided (Steth) technique, offer convenient and safe alternatives to standard methods but do not provide quantitative measurements. This study aimed to evaluate ETT cuff pressures and volumes of air inflated using the two subjective techniques (MOV and Steth) in pediatric patients. This prospective observational study was conducted at the Department of Anesthesiology, Faculty of Medicine, Khon Kaen University, Thailand. We included healthy pediatric patients aged 2 to 7 years undergoing elective surgeries under general anesthesia with a cuffed ETT. The primary objective of this study was to compare the mean ETT cuff pressures and volumes of air inflated using the two subjective inflation techniques (MOV and Steth method). The secondary objectives include identifying factors associated with inappropriate inflation and evaluating post-intubation complications. Sixty-four pediatric patients were analyzed. The overall mean ETT cuff pressure was 26.52 ± 8.68 cmH2O. The target was achieved in 46.88% of patients, with overinflation in 32.81% and underinflation in 20.31%. The mean ETT cuff pressure in the MOV group was 27.77 ± 8.89 cmH2O and in the Steth group was 25.33 ± 8.34 cmH2O, with a non-significant mean difference of 2.44 cmH2O (95% CI [-1.89, 6.77], p = 0.264). The mean volume of air inflated in the MOV group was 0.78 ± 0.25ml, and in the Steth group was 0.68 ± 0.22ml, with a non-significant mean difference of 0.10ml (95% CI [-0.01, 0.22], p = 0.084). Younger age, lower weight, and shorter height were significantly associated with an increased risk of overinflation. An ETT size with an internal diameter (ID) of 5mm was significantly associated with an increased risk of underinflation. No post-intubation complications were reported. Subjective inflation techniques (MOV or Steth) achieve target ETT cuff pressures in less than 50%, and carry the risks of both overinflation and underinflation,even without post-intubation complications. TCTR20211016001 (registered with the Thai Clinical Trials Registry on October 16, 2021).

New device for assessment of endothelial function: plethysmographic flow-mediated vasodilation (pFMD)

Measurement of flow-mediated vasodilation (FMD) in the brachial artery by using ultrasound is a well-established technique for evaluating endothelial function. To make the measurement quicker and simpler than the measurements of conventional ultrasound FMD (uFMD), we have developed a new noninvasive method, plethysmographic FMD (pFMD), to assess vascular response to reactive hyperemia in the brachial artery. The aim of this study was to determine the accuracy of measurement of pFMD in comparison to that of measurement of conventional uFMD. This study was a multi-center, cross-sectional study. We compared pFMD by a new device using cuff pressure and volume with conventional uFMD using ultrasound in 50 men (mean age, 41 ± 9 years). pFMD significantly correlated with conventional uFMD (β = 0.59, P < 0.001). In Bland–Altman plot analysis of pFMD and conventional uFMD, the mean difference of pFMD and conventional uFMD was 0.78%, and limits of agreement (mean difference ±2 standard deviations of the difference) ranged from −4.53% to 6.11%. We demonstrated validity of the new method for measurement of pFMD, which can automate the evaluation of endothelial function in a short time. Measurement of pFMD is simpler than measurement of conventional uFMD and may have reduced artificial bias compared to that of conventional uFMD measurement (URL for Clinical Trial: https://ethics.hiroshima-u.ac.jp/site/wp-content/uploads/2022/12/eki_giji20221213.pdf. Registration Number for Clinical Trial: E2022-0131).

Effect of Nebulized Lignocaine on Prevention of Postoperative Sore Throat following Laparoscopic Cholecystectomy

Post-operative sore throat (POST) is one of the common side effects of general anesthesia with endotracheal intubation. Several medications have been tried for the prevention of POST. Nebulized lignocaine is easily available, easily administered, cost-effective, and acts immediately with a short duration of action and minimal systemic effects with no long-term residual effects. We conducted this study to find the prevalence of POST when preoperative nebulization with 2% lignocaine is used in patients following laparoscopic cholecystectomy. We also studied the factors associated with POST. This study was done in 100 patients who underwent laparoscopic cholecystectomy and received preoperative lignocaine nebulization. The incidence of POST was measured at 0, 6, 12, and 24 hours postoperatively and various risk factors that might have predisposed for the development of POST were also studied. The mean age of the patients was 42.53±12.82 years. A total of 40 patients (40.0%) experienced POST at any time point during the study period. The majority of patients had mild i.e. Grade 1 POST (11-21%). Patients with a BMI &gt; 30 kg/m2, CL grade 4, high cuff volume, airway trauma, higher duration of intubation, and higher pneumoperitoneum duration had a greater incidence of POST at all post-operative periods. We concluded that nebulization of 5 ml of 2.0% lignocaine decreases the intensity and treatment requirement for POST and has minimal side effects. A higher incidence of POST is seen in patients who had a higher CL grading, higher BMI, high cuff volume, airway trauma, higher duration of intubation, and longer pneumoperitoneum duration.

Evaluation of Endotracheal Cuff Pressure and Volume of Air for Inflation of CUFF Following Intubation After General Anaesthesia for Elective Surgery

Evaluation of Endotracheal Cuff Pressure and Volume of Air for Inflation of CUFF Following Intubation After General Anaesthesia for Elective Surgery

Ventilation with the esophageal-tracheal Combitube during general anaesthesia: assessing complications in 540 patients.

The esophageal-tracheal Combitube (ETC) was developed for the management of difficult airways but can also be used for general anaesthesia. This clinical study collected data from patients undergoing anaesthesia with the ETC in order to assess the rate of complications. Five hundred forty patients were ventilated with the ETC. In 94.8% (512/540), insertion was performed for the first time by the respective physician. The following minor complications were observed: 38.7% sore throat, 30.9% blood on tube as sign of mucosal lesions and 17.0% cyanotic tongue. Experience decreased the risk of mucosal lesions (odds ratio [OR]: 2.3, 95% confidence interval [CI]: 1.5-3.5). A higher than recommended volume of the oropharyngeal cuff was associated with blood on the ETC (OR: 1.5, 95% CI: 1.0-2.3) and tongue cyanosis (OR: 2.3, 95% CI: 1.4-3.7). Ventilation for more than 2 h was associated with tongue cyanosis (OR: 2.2, 95% CI: 1.6-3.1) and tongue protrusion (OR: 1.4, 95% CI: 1.1-1.9). We conclude that the Combitube may be used for short procedures requiring general anaesthesia, but the high rate of minor complications limits its value when other alternatives such as a laryngeal mask airway are available. The tested method appears safe regarding major complications, but minor complications are common. Adherence to recommended cuff volumes, experience with the ETC and limiting its use to surgeries lasting less than 2 h might reduce the rate of complications.

Effect of Minimum Bronchial Cuff Volume of Left-Sided Double-Lumen Tube for One-Lung Ventilation on the Change in Bronchial Cuff Pressure during Lateral Positioning in Thoracic Surgery: A Prospective Observational Study

The minimum bronchial cuff volume (BCVmin) of a double-lumen tube (DLT) without air leaks during lung isolation may vary among individuals, and lateral positioning could increase the bronchial cuff pressure (BCP). We investigated the effect of initially established BCVmin (BCVi) on the change in BCP by lateral positioning. Seventy patients who underwent elective lung surgery were recruited and divided into two groups according to the BCVi obtained during anesthetic induction in each patient. Outcome analysis was conducted using data from 39 patients with a BCVi greater than 0 (BCVi > 0 group) and 27 with a BCVi of 0 (BCVi = 0 group). The primary outcome was a change in the value measured in the supine and lateral positions of the initially established BCP (BCPi; BCP at the time of BCVi injection), which was significantly larger in the BCVi > 0 group than in the BCVi = 0 group (1.5 (0.5-6.0) cmH2O vs. 0.0 (0.0-1.0) cmH2O; p < 0.001). BCVi was related to the left main bronchus (LMB) diameter (Spearman's rho = 0.676, p < 0.001) and the gap between the LMB diameter and the outer diameter of the bronchial cuff (Spearman's rho = 0.553, p < 0.001). Therefore, selecting a DLT size with a bronchial cuff that fits each patient's LMB may be useful in minimizing the change in BCP when performing lateral positioning during thoracic surgery. If the bronchial cuff requires unavoidable initial inflation, it is necessary to be aware that BCP may increase during lateral positioning and to monitor the BCP regularly if possible.

Effect of Fixed Tracheal Cuff Volume vs Fixed Tracheal Cuff Pressure on Hemodynamic Parameters and Postoperative Airway Complications, A Prospective Randomized Control Trial in a Tertiary Care Hospital

Background: The current study is aimed to compare the effect of fixed cuff volume and fixed cuff pressure technique on hemodynamic parameters and on postoperative complications.&#x0D; Methods: The prospective, randomised, controlled study was conducted in a tertiary care hospital with 100 patients aged between 18 to 60 yrs. The patients who are undergoing for elective surgeries under general anaesthesia were enrolled after obtaining ethical committee approval. Patients were randomized based on computer generated random numbers into two groups, fixed volume (7ml) group (group V, n-50) and fixed cuff pressure group (group P, n-50). The ETT cuff was filled with 7 ml of air in the fixed volume technique, and in the fixed cuff pressure group -cuff pressure was maintained at 20 cmH2O, after intubation. Tracheal tube cuff pressures were measured by AMBU cuff pressure gauge manometer. Hemodynamic parameters SBP, DBP, MAP and PR were noted at the time of cuff inflation, after extubation in the both the groups. Post-operative sore throat, hoarseness and cough was assessed at the time of extubation in the both the groups.&#x0D; Results: Mean age in both the groups was 41 years. Statistical significance (P&lt; 0.0001) was observed in Group P in systolic blood pressure (SBP), diastolic blood pressure (DBP), MAP, HR whereas no significance was seen in group V. The percentage of post-operative complications like hoarseness, cough, sore throat, and dysphagia were seen to be less in group P when compared to group V.&#x0D; Conclusion: With present data we could conclude that the fixed minimal cuff pressure (20 mm H2O) is an ideal and reliable technique in reducing the post-operative complications along with maintenance of hemodynamic parameters.&#x0D;

Comparison of Normal Saline and Alkalinized 2% Lignocaine to Reduce Emergence Phenomenon and Post-Intubation Morbidities: A Prospective, Double-Blind, Randomized Study.

Endotracheal intubation for airway management in general anesthesia is associated with post-intubation morbidities due to tracheal mucosa injury caused by endotracheal tube (ETT) cuff. Nitrous oxide (N2O) diffuses into tracheal tube cuffs filled with air. The rate of diffusion of N2O through the membrane is proportional to its concentration gradient. High-volume low-pressure cuffs expand with only a slight increase in pressure until fully inflated. At this point, owing to the inelasticity of the material, the cuff pressure rises rapidly. This increased pressure can damage the tracheal mucosa. This phenomenon can be avoided, if we inflate the cuff with either a liquid or a gas mixture identical to the inspired gas and monitor the cuff pressure and volume at regular intervals. When lignocaine is used to inflate the ETT cuff, it diffuses to the underlying tracheal mucosa. Thus reducing local irritation and inflammation of the airway through its local anesthetic action. Alkalinization of lignocaine increases its rate of diffusion across the ETT cuff. It also reduces the dose of local anesthetic required to achieve the desired result. We sought to determine the benefits of filling the ETT cuff with alkalinized lignocaine 2% over normal saline, to prevent ETT-induced emergence phenomenon and reduce the incidence of post-intubation morbidities like sore throat, hoarseness, and nausea. This prospective, randomized, double-blind, and comparative study was done at a multispecialty hospital. A total of 120 individuals ofAmerican Society of Anesthesiologists (ASA) physical status 1 and 2, posted for surgery under general anesthesia, were randomly selected and divided into two groups: alkalinized 2% lignocaine group (group L) and normal saline group (group S). After induction of general anesthesia, the airway was secured with appropriate-sized ETT. The ETT cuff was inflated with either of the study media. Continuous cuff pressure monitoring was done to keep cuff pressure below 30 centimeters of water (cm of H2O), at all times. At extubation, the response was evaluated in terms of percentage change in heart rate (HR) and blood pressure from baseline, coughing, bucking, and restlessness. All the surgeries lasted more than two hours. Post-operatively, the patients were evaluated for sore throat and hoarseness, at regular intervals of up to 24 hours. ETT cuff pressure was initially less in group S, which rose to a significantly higher level at extubation, compared to group L (p <0.001). At extubation, there was a significant increase in HR and systolic blood pressure (SBP) from baseline, in group S than in group L (p <0.001 and p=0.001, respectively).The incidence of cough and restlessness was less in group L, compared to group S (p<0.001 and p=0.002, respectively). Mean extubation time and emergence time was more in group S than in group L (p<0.001). Post-operatively, the incidence and severity of sore throat were significantly higher in group S than in group L (p<0.001). Meanwhile, the incidence of hoarseness and nausea was comparable in the two groups. Continuous ETT cuff pressure monitoring helps to keep cuff pressure below tracheal mucosa capillary occlusion pressure. Filling the ETT cuff with alkalinized lignocaine further reduces extubation response and post-intubation morbidities.

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.

A PRELIMINARY STUDY TO EVALUATE THE EFFECTIVENESS OF LARYNGEAL MASK AIRWAYS IN ANESTHETIZED BIGHORN SHEEP (OVIS CANADENSIS) LAMBS.

Chemical immobilization of wildlife, required for many biological studies and management events, often induces hypoxemia and respiratory depression. Laryngeal mask airways (LMAs) have shown promise as an efficient method of airway protection during anesthesia. Nineteen wild bighorn sheep (Ovis canadensis) lambs were immobilized using an IM combination of medetomidine (0.16 ± 0.062 mg/kg), azaperone (0.20 ± 0.058 mg/kg), and alfaxalone (0.54 ± 0.21 mg/kg) via remote injection. Upon recumbency, arterial blood gas parameters, minute ventilation (VE), tidal volume (VT), and respiratory rate were measured before and after LMA placement. The VE and VT were measured via respirometer. Time to LMA placement, cuff pressure, cuff volume, and ease of placement were measured. Medetomidine was reversed with IM atipamezole at five times the medetomidine dose upon completion of procedures. Pre- and post-LMA measurements were compared using a t test or a Wilcoxon signed-rank test based on normality of the data. The LMA provided a patent airway in all lambs with a significant (P < 0.0001) increase in VE (mean [95% CI]; pre-LMA: VE = 17.3 [16.2-18.5] L/min, post-LMA: VE = 19.8 [18.6-21.0] L/min) but did not have a significant impact on partial pressure of oxygen (PaO2; pre-LMA: corrected PaO2 = 45.2 [41.2-49.2] mm Hg, post-LMA: corrected PaO2 = 47.5 [43.3-51.7] mm Hg; P = 0.19) or partial pressure of carbon dioxide (PaCO2; pre-LMA: PaCO2 = 50.4 [46.6-53.2] mm Hg, post-LMA: PaCO2 = 51.6 [48.8-55.7] mm Hg; P = 0.035) following placement. This study demonstrated that the LMA is a viable option for airway protection in wild bighorn sheep.

Validity and success rate of noninvasive mean arterial blood pressure measurements in cf-LVAD patients: A technical review.

The life expectancy of patients with a continuous flow left ventricular assist device (cf-LVAD) is increasing. Adequate determination and regulation of mean arterial pressure (MAP) is important to prevent adverse events. Given the low pulsatility characteristics in these patients, standard blood pressure equipment is inadequate to monitor MAP and not recommended. We provide an overview of currently available noninvasive techniques, using an extensive search strategy in three online databases (Pubmed, Scopus and Google Scholar) to find validation studies using invasive intra-arterial blood pressure measurement as a reference. Mean differences with the reference values smaller than 5 ± 8 mm Hg were considered acceptable. After deduplication, screening, and exclusion of incorrect sources, eleven studies remained with 3139 successful MAP measurements in 386 patients. Four noninvasive techniques, using Doppler, pulse oximetry, finger cuff volume clamp, or slow upper arm cuff deflation, were identified and evaluated for validity and success rate in cf-LVAD patients. Here, a comprehensive technical background of the blood pressure measurement methods is provided in combination with a clinical use comparison. Of the reported noninvasive techniques, slow cuff devices performed most optimally (mean difference 1.3 ± 5.2 mm Hg). Our results are encouraging and indicate that noninvasive blood pressure monitoring options with acceptable validity and success rate are available. Further technical development and validation is warranted for the growing population of patients on long-term cf-LVAD support.

Comparative evaluation of three methods of endotracheal tube cuff inflation for adequacy of seal.

Intubation with cuffed endotracheal tube (ETT) is common in operation rooms, critical care, and emergency rooms. The pressure exerted by the cuff on the tracheal mucosa can lead to a reduction in blood flow to the tracheal wall and result in mucosal ischemia. There are many methods for ETT cuff inflation. Aim of the study was to compare the cuff pressures and volumes between the three methods of ETT cuff inflation. One hundred and twenty patients were randomized into three groups: Group SG (stethescope guided), group AL (audible leak), and group P (palpation). In group SG, the cuff was inflated by auscultating with the bell of the stethoscope over the thyroid cartilage for leak around cuff. In group AL, the cuff was inflated by listening for an audible leak around the cuff with observer's ear 5 cm away from the mouth of the patient. In group P, the cuff was inflated by palpating for a leak over the cricoid and trachea. The adequacy of the cuff seal was compared between the groups by assessing the volumes of additional air needed to stop the leak around the cuff as confirmed by supraglottic capnometry. The initial volumes needed to inflate the cuff were significantly more in the stethoscope (SG) and hearing (AL) groups than in the palpation (P) group (SG = 5.1 ± 1.4 ml, AL = 4.6 ± 1.6 ml, P = 3.1 ± 0.9 ml; SG and AL vs. P, P < 0.001). Additional cuff volumes required to achieve zero leak around cuff by supraglottic capnometry were 0.85 ± 1 ml in group SG, 1.3 ± 1.1 ml in group AL, and 2.237 ± 0.8 ml in group P (SG vs. P and AL vs. P; P < 0.001). Out of the auscultation-guided, audible leak-guided, and palpation-guided methods of ETT cuff inflation, the auscultation-guided and audible leak-guided methods achieve significantly better tracheal seal than the palpation-guided method.

Intracuff alkalinized lignocaine improves endotracheal tube induced emergence phenomenon

Background: Endotracheal intubation for airway management in general anaesthesia is associated with post intubation morbidities due to prolonged inflation of the ETT cuff with air. Lidocaine by instillation in the ETT cuff and its diffusion through semipermeable membrane causes reduction in mucosal irritation and inflammation. Objectives To compare the endotracheal tube (ETT) cuff pressure inflated with air or alkalinized lignocaine during anaesthesia and evaluate clinical symptoms such as coughing and sore throat (postoperative sore throat [POST]) following tracheal extubation. Material and Methods: This was a prospective randomized controlled study conducted over a period of 6 months. We included 60 patients in age group of 18–55 years posted for elective laparoscopic operative gynecological surgeries of duration more than 90 min under general anaesthesia with N2O‑O2 mixture. Patients were randomized using computer‑generated randomization table into air and lignocaine group. The ETT cuff was inflated with air or alkalinized lignocaine (2% lignocaine with 7.5% sodium bicarbonate, in the proportions of 19.0:1.0 ml) to the volume that prevented air leak using cuff pressure manometer. After extubation, an independent observer blinded to study group recorded the presence or absence of coughing and POST at immediately, 1,6,12h and 24 h postoperatively. Results: Demographic data, baseline characteristics (American Society of Anaesthesiologists grade, intracuff volume/cuff pressure at start of surgery), and duration of anaesthesia were comparable among study groups (P>0.05). Cuff pressure and volume achieved in the end of surgery were much noteworthy higher in air group as compared to lignocaine group (P < 0.0001). Incidence of coughing and POST at immediately, 1,6,12h and 24 h postoperatively was significantly higher in air group compared to lignocaine group. Conclusion: This study showed the significance of use of alkalinized 2% lignocaine in prevention of rise of cuff pressure and incidence of coughing and POST.

Association of Coronary Artery Atherosclerosis With Brain White Matter Hyperintensity.

We aim to determine, in healthy high-risk adults, the association between subclinical coronary artery disease and white matter hyperintensity (WMH) volume and location, independent of atherosclerotic risk factors. Seven hundred eighty-two asymptomatic first-degree relatives of index cases with early-onset coronary artery disease (<60 years old) from GeneSTAR (Genetic Study of Atherosclerosis Risk) with contemporaneous coronary computed tomography angiography and brain magnetic resonance imaging were analyzed. Multilevel mixed-effects linear regression models, accounting for family structure, evaluated the association of total WMH volume and 3 regions (deep WMH, periventricular WMH [PVWMH], or borderzone [cuff]) with markers of coronary artery disease. Separate models were created for total WMH, deep WMH, PVWMH, and cuff volumes, each, as dependent variables, across coronary computed tomography angiography variables, adjusted for covariates. Mean age was 51 years ±10, with 58% women and 39% African American people. Participants with any coronary plaque had 52% larger WMH volumes than those without plaque (95% CI, 0.24–0.59). Per 1% greater coronary plaque volume, total WMH volumes were 0.07% larger (95% CI, 0.04–0.10). Every 1% higher total coronary plaque volume was associated with 5.03% larger deep WMH volume (95% CI, 4.67–5.38), 5.10% PVWMH larger volume (95% CI, 4.72–5.48), and 2.74% larger cuff volume (95% CI, 2.38–3.09) with differences in this association when comparing deep WMH to PVWMH (P interaction, 0.001) or cuff (P interaction, <0.001), respectively. In healthy, high-risk individuals, the presence and volume of coronary artery plaque are associated with larger WMH volumes, appearing the strongest for PVWMH. These findings in high-risk families suggest a disease relationship in 2 different vascular beds, beyond traditional risk factors, possibly due to genetic predisposition.

Advanced cuff pressure control ventilation (ACPCV); a bench study of a new concept of mechanical ventilation

The concept of advanced cuff pressure control ventilation (ACPCV) is that the endotracheal tube (ETT) cuff volume could be controlled and allowed to exhale the gas through the vocal cords. The potential advantages of ACPCV are reduction of dead space, reduction of expiratory airway resistance, and preservation of vocal cord function. We developed the ACPCV system and investigated its performance in bench studies. The ETT cuff volume was regulated via four steps, depending on airway pressure and tracheal pressure. Two ventilatory settings were examined under several rates of spontaneous breathing efforts. Imposed expiratory resistance (RE ), imposed expiratory work of breathing (WOB), and auto-PEEP of ACPCV were compared with continuous mandatory ventilation (CMV). RE of ACPCV (2.6 ± 0.5 cm H2O/l/s) was significantly lower than that of CMV (11.6 ± 1.6 cm H2O/l/s) (p < 0.001). Expiratory WOB of ACPCV (0.25 ± 0.02 J/l) was significantly lower than that of CMV (0.54 ± 0.10 J/l) (p < 0.001). Auto-PEEP of ACPCV (−0.6 ± 0.2 cm H2O) was significantly lower than that of CMV (1.1 ± 0.7 cm H2O) (p < 0.001). ACPCV can significantly reduce RE and expiratory WOB by controlling the ETT cuff volume in synchronisation with mechanical ventilation.

Laryngeal mask airway protector generates higher oropharyngeal leak pressures compared to the laryngeal mask airway supreme: A randomized clinical trial in the ambulatory surgery unit.

Background and Aims:The Laryngeal Mask Airway (LMA) Protector™ is one of the latest introduced supraglottic airway devices. It provides access and functional separation of the respiratory and digestive tracts. Compared to the LMA Supreme™, it has two digestive ports, one to provide suction in the pharyngeal region and one for gastric tube insertion. High oropharyngeal leak pressure is a marker for safe ventilation when using LMA devices. We hypothesized that oropharyngeal leak pressure of the LMA Protector™ is 5 cm H2O higher than the oropharyngeal leak pressure of the LMA Supreme™ at various cuff volumes. Secondary outcome measures were ease of insertion of both masks, fiberoptic confirmation of correct positioning, failures of insertion, presence of blood staining, sore throat, presence of air leak and insertion time.Material and Methods:American Society of Anesthesiologists (ASA) I-III patients aged >18 years, scheduled for elective minor ambulatory surgery under general anesthesia with a LMA were included. Patients were randomized in the LMA Protector™ or LMA Supreme™ group based on a computer-generated random sequence table. After general anesthesia induction, oropharyngeal leak pressures were measured.Results:Oropharyngeal leak pressures were significantly higher (P < 0.0001) for LMA Protector™ compared to LMA Supreme™ at different cuff volumes and a cuff pressure of 65 cm H2O. Insertion time was significantly higher for the LMA Protector™ (29 sec) [interquartile range (IQR) 23, 35] compared to the LMA Supreme™ (19 sec) (IQR 16, 22) (P < 0.0001). There were no statistically significant differences in ease of insertion (number of attempts for succesful positioning), failures of insertion, presence of blood staining, sore throat or presence of air leak.Conclusion:Oropharyngeal leak pressures were consistently higher (>5 cm H2O) for LMA Protector™ compared to LMA Supreme™. LMA Protector™, therefore, allows effective ventilation at higher airway pressures than LMA Supreme™.Trial Registration:http://clinicaltrials.gov.NCT03462550.

P0411 / #1109: IS TRACHEAL TUBE CUFF ASSOCIATED WITH POST EXTUBATION STRIDOR IN PEDIATRIC SUBJECTS?

Aims & Objectives: to describe association of PES with cuffed tracheal tube use and related factors in pediatric subjects connected to MV more than 12 hours. Methods: Observational prospective study. Eighty-one intubated subjects admitted to PICU at University Hospital were follow after 12 hours of MV until 48 hours after extubation in order to found PES. Cuff volume and pressure inflation values with minimum volume occlusive test (MVOT) were measure two times by day until extubation. Main outcome was PES occurrence after 48 hours post extubation. Association of PES and cuff was estimate by logistic regression. Cuff volume and pressure relationship, ventilator associate pneumonia (VAP) compared with previous years, and extubation failure with PES association were studied. Results: Cuff use was 64.2%, median age 4 (2; 12) months, MV hours 72 (41-118) hours, and PES occurred in 9.8%. There was no association between cuff use and PES (OR 4.36 [95%CI 0.51 to 37.31; p-value= 0.179]). Both types of cuff were no associated with PES. No other clinical values were associated with PES. Moderate relation between volume and pressure was observe in both types of cuff. No significant differences observed in VAP incidence (VAP= 0) compared with previous years. Conclusions: Cuffed tracheal tube is not associated with PES. Cuff use were not associate with extubation failure nor VAP. Other variables derived from cuff use and other recorded clinical variables were not associate with PES.

A sore throat after endotracheal intubation in Sanglah General Hospital 2017

Background: Cuff volume additionally impacts a postoperative sore throat and dysphagia. The rate of a sore throat has likewise been discovered to be higher in the event of Laryngeal Mask Airway (LMA) than that of endotracheal intubation (ETT).Aim: To know the duration of a sore throat and level of severity of a sore throat after endotracheal intubation among patients of Sanglah General Hospital.Method: This cross sectional study was conducted on patients of Sanglah General Hospital. There were 100 students were participated in this study. They were asked to fill up a self-administered questionnaire. The variables assessed were their duration towards patients who have used anesthetic during surgery.Result: About 54% of 100 patient of Sanglah General Hospital, respectively had a sore throat for 4 to 6 days after endotracheal intubation. However, 28% of patients had a sore throat from day one to day three after the endotracheal intubation method. For the severity of a sore throat over 50% of the patients have experienced pain in eating, drinking, talking and for some people it has given them an enormous side effect towards their daily activity. Though the overall duration and severity of a sore throat among the patient, lasted less than a week and for the severity patient have voted respectively high. Patients with good diet control after the surgery tend to heal faster.

What is the Adequate Cuff Volume for Tracheostomy Tube? A Pilot Cadaver Study

ObjectiveTo determine the patterns of tracheostomy cuff pressure changes with various air inflation amounts in different types of tracheostomy tubes to obtain basic data for appropriately managing long-term tracheostomy.MethodsWe performed tracheostomy on a 46-year-old male cadaver. Three types of tracheostomy tubes (single-cuffed, double-cuffed, and adjustable flange), divided into 8 different subtypes based on internal tube diameters and cuff diameters, were inserted into the cadaver. Air was inflated into the cuff, and starting with 1 mL air, the cuff pressure was subsequently measured using a manometer.ResultsFor the 7.5 mm/14 mm tracheostomy tube, cuff inflation with 3 mL of air yielded a cuff pressure within the recommended range of 20–30 cmH2O. The 7.5 mm/24 mm tracheostomy tube showed adequate cuff pressure at 5 mL of air inflation. Similar values were observed for the 8.0 mm/16 mm and 8.0 mm/27 mm tubes. Double-cuffed tracheostomy cuff pressures (7.5 mm/20 mm and 8.0 mm/20 mm tubes) at 3 mL air inflation had cuff pressures of 18–20 cmH2O at both the proximal and distal sites. For the adjustable flange tracheostomy tube, cuff pressure at 6 mL of cuff air inflation was within the recommended range. Maximal cuff pressure was achieved at inflation with almost 14 mL of air, unlike other tube types.ConclusionVarious types of tracheostomy tubes showed different cuff pressures after inflation. These values might aid in developing guidelines For patients who undergo tracheostomy and are discharged home without cuff pressure manometers, this standard might be helpful to develop guidelines.

Incidence of gastric insufflation at high compared with low laryngeal mask cuff pressure: A randomised controlled cross-over trial.

The success of ventilation with a laryngeal mask depends crucially on the seal between the mask and the periglottic tissue. Increasing the laryngeal mask's cuff volume is known to reduce oral air leakage but may lead to gastric insufflation. We hypothesised that a lower cuff pressure would result in less gastric insufflation. We sought to compare gastric insufflation with laryngeal mask cuff pressures of 20 cmH2O (CP20) and 60 cmH2O (CP60) during increasing peak airway pressures in a randomised controlled double-blind cross-over study. We also evaluated the incidence of gastric insufflation at the recommended peak airway pressure of 20 cmH2O or less and during both intermittent positive airway pressure and continuous positive airway pressure. After obtaining ethics approval and written informed consent, 184 patients ventilated via laryngeal mask received a stepwise increase in peak airway pressure from 15 to 30 cmH2O with CP20 and CP60 in turn. Gastric insufflation was determined via real-time ultrasound and measurement of the cross-sectional area of the gastric antrum. The primary endpoint was the incidence of gastric insufflation at the different laryngeal mask cuff pressures. Data from 164 patients were analysed. Gastric insufflation occurred less frequently at CP20 compared with CP60 (P < 0.0001). Gastric insufflation was detected in 35% of cases with CP20 and in 48% with CP60 at a peak airway pressure of 20 cmH2O or less. Gastric insufflation occurred more often during continuous than during intermittent positive airway pressures (P < 0.01). A laryngeal mask cuff pressure of 20 cmH2O may reduce the risk of gastric insufflation during mechanical ventilation. Surprisingly, peak airway pressure of 20 cmH2O or less may already induce significant gastric insufflation. Continuous positive airway pressure should be avoided due to an increased risk of gastric insufflation. The study was registered in the German Clinical Trials Register (DRKS00010583) https://www.drks.de.