Intracuff Pressure Research Articles

EVALUATION OF POSTOPERATIVE AIRWAY RELATED ADVERSE EFFECTS BY USING INTRACUFF DEXAMETHASONE VERSUS INTRACUFF ALKALINISED LIGNOCAINE - RANDOMISED DOUBLE BLIND CONTROLLED STUDY

Background Securing airway with ETT is the gold standard for General anesthesia(GA).This method confers the protection of airway from aspiration of gastric contents and facilitates positive pressure ventilation. However, post-intubation airway-related adverse effects are known to be caused by endotracheal intubation like postoperative coughing on the tube, restlessness, hoarseness and sore throat. Therefore this study was undertaken to reduce post intubation complications. ObjectiveThestudy was conducted to compare intracuff dexamethasone and intracuff alkalinised lignocaine with respect to postoperative cough, hoarseness and sore throat scores. Methods A randomized double blind study was conducted in 200 patients of ASA I,II,III and age between 18 to 60 yrs undergoing surgeries under GA for more than 2 hours, Patients who need nasogastric tube or throat pack were excluded from study. A computer generated randomisation with double blind technique was used to distribute them into Group L and Group D 100 each. In Group L, ETT cuff was inflated with 2ml of 2% lignocaine +2-3ml of 7.5% Sodium bicarbonate and in Group D cuff was inflated with 2ml of dexamethasone + 2-3ml of Normal saline. Intracuff pressure was monitored throughout the surgery and was maintained below 28 cm H2O. ResultsThe severity of cough and hoarseness was found higher in group D at 2 hours which was statistically significant (P< 0.05). However, there was no significant difference at 8hrs,16hrs and 24hrs in both the groups. Conclusion We conclude that post operative airway related adverse effects are less when cuff was inflated with alkalinized lignocaine as compared to dexamethasone as liquid media.

Studying the Optimal Air Volume Needed for Inflating the Cuff of an Endotrecheal Tube: A Clinical Observational Study

Abstract: An endotracheal tube (ETT) is a polyvinyl chloride (PVC) flexible plastic tube, this tube is placed into the trachea through the mouth or nose. During the course of general anaesthesia or when a patient is unable to breath by him / herself the endotracheal tube is placed for the maintenance of breathing when it is necessary to sedate the patient, and airway protection is thus lost. Endotracheal tube is used for the protection of airway from any foreign body so that air can pass into and out of the lungs by which it can maintain the airway. This tube needs a special consideration with regards to cuff inflation for creating a seal in between trachea and endotracheal tube for preventing chances of aspiration and leakage of air. Therefore, we are conducting this study to find the optimal air volume needed to inflate the cuff of ETT and minimise the complications associated with over and underinflation of cuff. The conclusion of our study shows that There was a tendency to overinflate the ETT cuff, resulting in high intracuff pressure. The estimated optimal air volume needed for inflating the ETT cuff was about 6.05 ml for men and 5.45 ml for women.

Comparative Efficacy of Intracuff 1% and 2% Alkalinized Lignocaine with Saline on Endotracheal Tube-Induced Hemodynamic Changes and Emergence Phenomena in Neurosurgical Patients.

Introduction Extubation is associated with hemodynamic changes and emergence phenomena leading to cough, sore throat, dysphonia, and dysphagia in the postoperative period. The aim of our study was to compare intracuff 2% alkalinized lignocaine with 1% alkalinized lignocaine and saline in reducing endotracheal tube induced emergence phenomena and haemodynamic changes at extubation in neurosurgical patients. Materials and Methods In this randomized controlled study, 90 adult patients of either sex, scheduled to undergo neurosurgical procedures were randomly divided into three groups of 30 each to receive either 1% alkalinized lignocaine (AL1), 2% alkalinized lignocaine (AL2), or saline as cuff inflation media. Intracuff pressures and haemodynamic variables were noted intraoperatively and during emergence. The presence of postextubation cough, sore throat, dysphonia, and dysphagia were monitored until 24 hours postoperatively. Data were analyzed using Chi-square test and ANOVA. A p -value of less than 0.05 was considered significant. Results The intracuff pressures were significantly less with alkalinized lignocaine as compared to saline, after 3 hours of induction. Post extubation, hemodynamic parameters and incidence of coughing and bucking at extubation were significantly less in Groups AL1 ( p = 0.024) and AL2 ( p = 0.02) as compared to saline. On assessment of laryngotracheal morbidity, the incidence of coughing was found to be significantly less with 2% alkalinized lignocaine as compared to saline ( p = 0.021) at 1 hour after extubation. Sore throat was significantly less in Groups AL1 and AL2 as compared with saline at 1 hour ( p = 0.008, 0.002 respectively) and 8 hours ( p = 0.01 in both groups), and in Group AL2 versus saline at 24 hours ( p = 0.044) after extubation. The incidence of dysphonia was significantly less in Groups AL1 and AL2 as compared with saline at 1 hour ( p = 0.016, p = 0.002) and 24 hours ( p = 0.012 in both groups) and in Group AL2 versus saline at 8 hours (p = 0.03) postoperatively. No significant differences were noted between 1% alkalinized lignocaine and 2% alkalinized lignocaine. Conclusion Intracuff alkalinized lignocaine 1% and 2% were significantly better than saline in reducing coughing and bucking at extubation, post extubation haemodynamic changes and incidence of postoperative cough, sore throat, and dysphonia.

A Study to Evaluate the Efficacy of Preoperative Low-dose Nebulised Dexamethasone in Decreasing the Incidence of Postoperative Sore Throat in Patients Undergoing Surgery Under General Anaesthesia

Background and Aims: Postoperative sore throat (POST) is a stereotypical postoperative complication that usually occurs in approximately 21%–65% of patients who are under general anaesthesia and is ranked around eighth among the most undesirable subjective and unpleasant complaints by the society of American anaesthesiologist after general anaesthesia. As airway management is a crucial factor in the causation of POST, various methods, especially non-pharmacological, are used to reduce the incidence of postoperative sore throat with the use of a small-sized endotracheal tube with low intracuff pressures. The tracheal tube is applied with other agents that may help in reducing the symptoms such as steroids, lozenges, lignocaine, ketamine gargles, inhalation of steroids (also included in pharmacological methods used for reducing the incidence of postoperative sore throat). Aim and Objective: The aim of this study was to evaluate the efficacy of prophylactic low-dose nebulised dexamethasone for decreasing the incidence of post-extubation sore throat and to evaluate the complications of low-dose dexamethasone nebulisation in patients undergoing surgery under general anaesthesia. Patients and Methods: The study was done in the Anaesthesiology Department of Maharishi Markandeshwar Institute of Medical Sciences and Research (MMIMSR) Mullana, Ambala, after institutional ethical committee approval and written, informed consent was obtained from the patients from March 2021 to March 2022 with a group size of Group S – 25 patients and Group D – 25 patients. Observation and Results: The results showed that patients in the dexamethasone group had a lower POST rate compared to the control group. Conclusion: We concluded that a low dose of 4 mg dexamethasone was effective in reducing the incidence and severity of POST in patients after anaesthesia, and no side effects compared to 4 mg normal saline.

Comparative evaluation of self-pressurized Air-Q® and Proseal™ LMA® in patients undergoing elective surgery under general anaesthesia: A randomized clinical trial.

Intra-cuff pressure of Air-Q self-pressurized laryngeal airways (Air-Q SP) balances airway pressure and adapts to patient's pharyngeal and periglottic structures, thus improves oropharyngeal leak pressure (OLP).This study was performed to compare efficacy of Air-Q SP with Proseal laryngeal mask airway (PLMA) in patients undergoing elective surgery. The study design was prospective, randomized and controlled. Ninety patients were randomly assigned to Air-Q SP or PLMA group. All patients were premedicated and shifted to operation theatre. Monitoring was instituted. After securing IV-line, induction with inj. Morphine + Propofol, relaxation with inj. Vecuronium was done. Supraglottic was inserted according to group allocation. Outcome measures were OLP, fibreoptic view of larynx, success rate, device insertion parameters, haemodynamic and respiratory parameters and post-operative laryngopharyngeal complications. Neostigmine + glycopyrrolate were given, device was extubated. All supraglottic airway devices (SADs) were successfully placed in two attempts. The mean initial OLP, OLP at 10 minutes, and device insertion time were significantly lower in Air-Q SP group. Fiber-optic laryngeal view grading was significantly better with Air-Q SP. No significant difference was observed with respect to rate of successful insertion in first attempt, ease of insertion, and manipulations required. The hemodynamic/respiratory parameters and post-operative sore throat in the two both groups were similar. Proseal LMA has a higher OLP than Air-Q SP but average insertion time was better, and fiber-optic grading of laryngeal view was shorter with Air-Q SP. However, Air-Q SP and Proseal LMA were both effective for lung ventilation.

A bench study on the prevention of lung-to-lung aspiration with double-lumen endobronchial tubes and bronchial blockers

Effective lung isolation prevents lung-to-lung aspiration during thoracotomy for the management of hemoptysis. Double-lumen endobronchial tubes (DLT) and bronchial blockers are commonly used for lung separation during thoracic surgery. In this study, the fluid-sealing characteristics of the endobronchial cuffs of three different commercially available DLTs (Broncho-Cath with a polyvinylchloride cuff, Broncho-Cath with a polyurethane cuff, and Human Broncho with a silicone cuff) and two different bronchial blockers (Arndt and Coopdech bronchial blockers) were evaluated using a benchtop model. The lateral decubitus position for the surgical management of bleeding from the right lung was simulated. The artificial tracheobronchial tree was placed horizontally, with the left bronchus in the dependent position and the right bronchus in the non-dependent position. In the DLT experiments, the tracheobronchial tree was intubated with left-sided DLTs, and the endobronchial cuff was inflated to maintain the intracuff pressure at 25 cmH2O. In the experiments with bronchial blockers, each bronchial blocker was inserted into the right bronchus, and the endobronchial cuff was inflated to seal the main bronchus. A fluid leakage test around the endobronchial cuff was performed using three different types of DLT (size 35, 37, and 41 Fr, each) and two different types of bronchial blockers (9 Fr). The 5 mL of colored water was poured into the right bronchus to simulate the blood flow from the operative side, and the times to the first and 100% leakage around the endobronchial cuff were recorded. Each bronchial blocker showed significantly less leakage over time than the other DLTs (P < 0.05). Fluid was not fully leaked around the cuffs for 24 h with either bronchial blocker. The times to first and 100% leakage were not significantly different among different types of DLTs. The times to first and 100% leakage did not also differ among the three different sizes of each type DLT. There was no significant difference in the time to first leakage around the endobronchial cuffs between Arndt and Coopdech bronchial blockers. Bronchial blockers provided a more effective seal against lung-to-lung aspiration than DLTs in the lateral decubitus position for thoracotomy in the benchtop model.

Tracheal tubes intracuff pressure difference between neutral head-neck position and lateral rotation in patients with tracheal intubation

BackgroundTracheal tubes (TT) cuffs seal the airway to facilitate positive pressure ventilation and prevent aspiration due to subglottic secretions. Changes in head-neck position can affect TT intracuff pressure. An increase or decrease in TT intracuff pressure can cause many morbidities. The purpose of this study was to determine the effect of lateral head-neck rotation on TT intracuff pressure. MethodsForty (40) patients aged 18–64 years undergoing elective surgery under general anesthesia were selected in this study. After tracheal intubation, the TT cuff was inflated with a minimal occlusive volume technique. The TT was placed on the right side of the mouth. Changes in TT intracuff pressure were assessed before and after the position change. TT intracuff pressure was measured with a cuff inflator in the neutral head position. After lateral head-neck rotation (60°), the intracuff pressure was remeasured. ResultsThe mean intracuff pressure increased from 25.5 + 1.64 to 29.4 + 1.71 cmH2O after lateral head-neck rotation (p = 0.000). There was a significant difference between neutral position and lateral head rotation (p < 0.05). The use of a minimal occlusive volume technique with a volume of 4–7 cc was able to produce TT intracuff pressure between 22 and 28 cmH2O (normal range 20–30 cmH2O). The difference in TT intracuff pressure after lateral head-neck rotation was 3.9 ± 1.31 cmHO2. ConclusionTracheal tube intracuff pressure is significantly higher after the head-neck position change from neutral to lateral rotation. Measurement of intracuff pressure after lateral head rotation is beneficial to avoid possible adverse effects of position-related pressure changes.

Evolution of the concepts of pediatric airway and endotracheal intubation

The tenets of airway anatomy and management continue to be reevaluated and challenged as our knowledge increases. This has led to a better understanding of the pediatric airway and its critical differences from adults. This evolving understanding of the pediatric airway size and shape has significant clinical implications to airway management in the operating room, emergency department, and the intensive care unit. The first significant change in clinical practice was the transition to the routine use of cuffed endotracheal tubes (ETTs). This was facilitated by the availability of the Microcuff® with a polyurethane cuff and a redesigned position of the cuff on the shaft of the ETT without the Murphy’s eye. Additional attention to the design and the location of the cuff on the ETT may be necessary as well as to markings for depth of intubation on the shaft of the ETT to ensure that the cuff is placed fully below the cricoid ring following endotracheal intubation. Inflation of the cuff with high intracuff pressures within the cricoid ring may compromise perfusion of the tracheal mucosa and result in airway injury.

Flexible intubation videoscope guided assessment of gastric channel opening in supraglottic airway devices- A proxy for intracuff pressure?

Flexible intubation videoscope guided assessment of gastric channel opening in supraglottic airway devices- A proxy for intracuff pressure?

Accuracy of pilot balloon palpation for cuff pressure assessment in small versus large sized tubes: a prospective non-randomized observational study

Pilot balloon palpation is still a commonly used method to evaluate cuff pressure of the endotracheal tube after intubation. This study determined whether the size of the tracheal tube influenced the accuracy of pilot balloon palpation. A prospective observational analysis of 208 patients intubated with an endotracheal tube of internal diameter (ID) 6.0 or 8.0 was conducted. An anesthesiologist judged the cuff pressure by manual pilot balloon palpation, and then measured the cuff pressure with a pressure gauge. Cuff pressure exceeding 20–30 cmH2O was defined as false recognition. The intracuff pressure was significantly higher in ID 6.0 tube than in the ID 8.0 tube (41.9 ± 18.8 cmH2O vs. 30.3 ± 11.9 cmH2O, p < 0.001). The number of patients that were mistakenly perceived to have appropriate cuff pressure by pilot balloon palpation was significantly higher in the ID 6.0 group compared to the ID 8.0 group (85 (81.7%) vs. 64 (61.5%), p = 0.001). Therefore, a smaller tube size may further increase risk of inaccurate measurement by pilot balloon palpation and although pressure gauge is recommended for all sizes to maximize accuracy, groups with increased risk factors should be targeted for standardized use of the pressure gauge.

Negative intracuff pressure inside the deflated cuff of an endotracheal tube.

Dear Editor, Inflation and deflation of the cuff of an endotracheal tube (ETT) is a routine part of airway management. Inflation of the cuff ensures a seal that enables intermittent positive pressure ventilation and provides safety from aspiration of gastric contents.[1] Like inflation, deflation of the ETT cuff carries its own importance prior to extubation and during nasotracheal intubation. Quantification of cuff inflation is translated as positive intracuff pressure, which is widely measured using a cuff manometer.[2] However, there is no provision to quantify the intracuff pressure of a deflated cuff. We report a case indicating negative intracuff pressure inside a deflated cuff. A 26-year-old gentleman who had a history of road traffic accident three days back, presented with restricted mouth opening. The patient was diagnosed with a fractured mandible and was scheduled for fixation under general anaesthesia. The pre-anaesthetic check-up was within normal limits. Airway examination revealed a mouth opening of around 3 cm and a Modified Mallampati score of 3. The airway management plan was nasotracheal intubation using McGrath video laryngoscope. On the day of the surgery and after the induction of general anaesthesia, an armoured ETT of 7.0 mm internal diameter was introduced through the right nostril after deflating the cuff. After inserting around 10 cm of the ETT, the McGrath video laryngoscope size 3 was introduced in the oral cavity. As it was further advanced looking at the video screen, a pool of blood was observed in the oropharynx along with the ETT. The oropharynx was suctioned and as the vocal cords became visible, the ETT was inserted through the larynx and into the trachea. As the pilot balloon was picked up to inflate the cuff, blood was noticed in the pilot balloon and the inflation line [Figure 1]. Furthermore, we failed to inflate the cuff. The cuff was considered ruptured and the ETT was replaced. The inference was that the simultaneous rupturing of the cuff and the negative pressure contained inside the deflated cuff caused in-drawing of the surrounding blood into the inflation line and the pilot balloon.Figure 1: Blood inside the inflation line and pilot balloon of the endotracheal tubeIn a model experiment, the deflated cuff was ruptured in a bowl of coloured dye, and there was immediate siphoning of dye in the inflation line and the pilot balloon. This case and the experimental model highlighted that an unquantified negative pressure is contained inside the deflated cuff, contrary to the expected zero or atmospheric pressure. Any breach in the integrity of the cuff system acquired during the procedure of endotracheal intubation is unidentified until the attempted inflation of the cuff. The unusual observation of blood in the inflation line in the reported case indicated the breach. The clinical utility of this unique observation requires further exploration and study. Identical to the negative pressure test of the low-pressure system of an anaesthesia machine, a negative pressure test can be designed to confirm the integrity of the ETT cuff system prior to tracheal intubation. A conventional test for the cuff system needs inflation of the cuff system, which mandates deflation of the cuff prior to intubation: this makes it a multi-step process.[3,4] A negative pressure test, however, consists of a single step of cuff deflation and the deflated cuff for a pre-defined time period confirms integrity of the cuff system. Furthermore, ETTs can be factory supplied with a specified negative intracuff pressure rather than zero pressure. This practice bypasses the testing of the cuff system and requires only a mere visual inspection of the collapsed cuff through the transparent packing. Unlike cuff inflation, deflation of the cuff has not been not standardised. It is by tactile perception that cuffs are deflated before each extubation or prior to nasotracheal intubation. A measuring device can be designed to estimate the negative pressure inside the cuff system with a fixed standard rather than just the binary of yes or no. To conclude, this novel entity can hold a prominent place in the practice of anaesthesiology and opens up an arena of further research activity. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patient understands that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Pre-hospital emergency cricothyrotomy in dogs part 2: Airway sealing and ventilation using cricothyrotomy tubes.

Cricothyrotomy (CTT) has been recommended for use in the pre-hospital setting for military working dogs and Operational K9s during airway emergencies. Although the CTT can establish a patent airway for spontaneous ventilation, the ability to seal the airway and provide positive pressure ventilation (PPV) using tubes designed for humans has not been determined. Using various CTT tubes placed in cadaver dog airways, this study aimed to determine: (1) Whether the tube cuff could create a functional airway seal with safe intra-cuff pressures; (2) The magnitude of delivered tidal volume (TV) loss during a standard breath to assess the possibility of delivering an adequate tidal volume with a bag-valve device (BVM); (3) The best performing tubes for either test; (4) The reasons behind the findings using observations from upper airway endoscopy, dissection, and measurements. Cadaver dogs of similar weights to MWD and Operational K9 breeds had various CTT tubes placed including three from commercial kits, a standard endotracheal tube, and a tracheostomy tube. The minimum occlusive volume technique was used to inflate the tube cuff and a pressure ≤ 48 cm H2O with an adequate seal was considered successful. Individual TVs were calculated for each dog and added to the volume lost during delivery of a standard breath from an ICU ventilator. Endoscopy and airway dissection were performed to assess the relationship between tubes cuffs and the airway. The tubes from the CTT kits performed poorly with regards to producing an airway seal with the H&H tube failing to seal the airway all tests. Tracheal dimensions were significantly associated with successful airway sealing (P = 0.0004). Tidal volume loss could be compensated using a BVM in 34/35 tests with the H&H tube in cadaver 8 the only to fail. Tracheal airway sealing is influenced by airway anatomy when tube cuffs are inflated to a target pressure and larger tubes do not always provide a better seal. The CTT tubes tested have the potential to facilitate ventilation with a BVM under the conditions set in this study. The 8.0 mm endotracheal tube performed the best and the H&H the worst in both tests.

Evaluation of the endotracheal tube cuff pressure changes during cardiac operations under cardiopulmonary bypass.

Introduction: Tracheal intubation is used for most operations under general anesthesia. Prolonged hyperinflation of the tube cuff can compromise tracheal mucosal perfusion, and low pressure of the cuff may cause some other complications. The aim of this study was the evaluation of changes in intra-cuff pressure in patients undergoing cardiac surgeries under cardiopulmonary bypass. Methods: In an observational study 120 patient's candidate to cardiac operations under cardiopulmonary bypass were enrolled. After induction of anesthesia and tracheal intubation by same tracheal tubes, tracheal tube cuff pressure was adjusted to 20-25 mm Hg (T0). Then the cuff pressure was measured at beginning of CPB (Cardio Pulmonary Bypass) (T1), at 30º hypothermia (T2) and after separation from CPB (T3). Results: The mean cuff pressure was 33.5±7.3, 28.9±5.4, 25.6±5.2 and 28.1±3.7 at T0, T1, T2 and T3 respectively. Intra- cuff pressure changed significantly during cardiopulmonary bypass. Conclusion: The mean intra-cuff pressure was decreased during hypothermic cardiopulmonary bypass. The decrease in cuff pressure may protect the tracheal mucosa against hypotensive ischemic injury in these patients.

Air Versus Distilled Water Cuff Inflation using Cuffill (Digital Cuff) in Adult Patients Undergoing General Anaesthesia

Introduction: An essential part of anaesthesia is endotracheal intubation. The Endotracheal Tube (ETT) cuff pressure must not be higher than the predicted 22-30 mmHg tracheal perfusion pressure. If the ETT’s cuff is inflated with air while under nitrous oxide+oxygen anaesthesia, the cuff pressure may increase dangerously and result in ischaemia of the tracheal mucosa. Hence, distilled water as an alternative agent to air for inflation of cuffs of ETTs was used in the present study. Aim: To determine whether inflating the ETT cuff with distilled water, instead of air changes the pressure over time. To evaluate changes in cuff pressure over time, and to assess the knowledge about endotracheal cuff pressure monitoring with cuffill. Materials and Methods: The randomised clinical study was conducted from February 2022 to April 2022. The study included 50 patients undergoing elective surgery under general anaesthesia who were randomly divided into two groups. In Group-A, distilled water was used and in Group-B, air was used to inflate the cuffs of ETTs. General anaesthesia was given with nitrous oxide, oxygen and relaxant technique. The intra-cuff pressures of ETT cuffs were recorded by AG cuffill. Increase of pressures with time were recorded and analysed. Results: Mean ET cuff pressure by cuffill with air (Group-B) was 26±2.43 mmH2 O after 0 minutes of intubation. After 15 minutes of intubation mean ET cuff pressure was 31.80±3.39 mmH2 O. Mean ET cuff pressure by cuffill with distilled water (Group-A) was 25.56±2.02 mmHg after 0 minutes of intubation. After 15 minutes of intubation, mean ET cuff pressure was 28.5±2.26 cmH2 O. There was a pressure difference observed between the groups with a mean difference of 3.217, t-value of 4.743 and a p-value of 0.001. Conclusion: For the purpose of inflating the cuffs of ETTs when the patient is under general anaesthesia with the use of nitrous oxide, oxygen, and relaxant method, distilled water may be considered a more desirable agent than air.

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.

Two Birds, One Stone: Awake Extracorporeal Life Support.

Case A 55 year old female, no previous medical history, underwent out-of-hospital cardiac arrest. Advanced cardiac life support (ACLS) was initiated, with return of spontaneous circulation after 30’ of conventional resuscitation efforts. At first hospital arrival coronary angiography and successful percutaneous transluminal angioplasty were performed to treat right coronary artery stenosis. Incidentally, lung computed tomography (CT) revealed signs of aspiration pneumonia (Figure 1). Moreover, as a result of improper out-of-hospital endotracheal tube (ETT) positioning (ID 7.5/OD 10.7 mm) during ACLS, the patient suffered iatrogenic airway injury, as confirmed by bronchoscopy (12 x 19 mm respectively sagittal and longitudinal axis, Figures 1 and 2).Figure 1.: Tracheal injury (white arrow) and aspiration pneumonia at CT scan performed at hospital admission: distal end of the endotracheal tube in the main right bronchus (white arrow); retrocarinal pneumomediastinum (black arrow); evidence of basal consolidation in the left lung. CT, computed tomography.Figure 2.: Evolution of tracheal injury (white arrows) at fiberoptic bronchoscopy. A: day 1 large tear in the pars membranacea (posterior wall) of the trachea, extended to the emergence of the main right bronchus (white arrow), with hyperemic peripheral area; (B) day 7: partial re-epithelialization of the posterior wall, and decreased mucosal hyperemia; (C) day 24 evidence of resolution of the injury, with a residual linear scar. ECMO, extracorporeal membrane oxygenation; LMB, left main bronchus; RMB, right main bronchus.Pneumonia worsened rapidly to acute respiratory distress syndrome (ARDS) over subsequent days, and the presence of tracheal injury complicated mechanical ventilation management, so femoro-femoral veno-venous extracorporeal membrane oxygenation (V-V ECMO) was initiated in referring hospital (details in online supplement, Supplemental Digital Content 1, https://links.lww.com/ASAIO/A876). After cannulation the patient was transferred to referral center. For the first 2 days deep sedation and neuromuscular blockade were deemed necessary to provide lung protective ventilation (settings detailed in online supplement, Supplemental Digital Content 1, https://links.lww.com/ASAIO/A876). Due to the location of the distal end of the ETT cuff tube, the intracuff pressure was strictly monitored and maintained at 20 mm Hg. On minimal ECMO support gas exchange rapidly improved. To improve tracheal tear healing the patient was extubated on third day of ECMO, and high flow nasal oxygen (HFNO) initiated. After 8 days successful weaning trial was attempted, and decannulation performed. Follow up CTs demonstrated progressive resolution of lung disease and airway injury, with reabsorption of pneumodediastinum. Since ECMO weaning the patient remained eupneic; she was discharged home with almost complete lung recovery and intact tracheal wall (evolution of injury and clinical course are depicted in supplementary figures 1 and 2, Supplemental Digital Content 1, https://links.lww.com/ASAIO/A876). Full neurologic recovery was achieved, with no signs of physical impairment.

Comparisons of the segments of left-sided double-lumen tracheobronchial tubes as industrial products.

BackgroundAlthough there are at least seven manufacturers producing left-sided double-lumen tubes (DLTs), there have been few reports comparing the segments of these DLTs. In this study, we compared various segments of left-sided DLTs further.Materials and methodsWe examined five manufacturers’ left-sided DLTs: Mallinckrodt, Portex, Rüsch, Sheridan, and Daiken-medical. We conducted the following six trials or measurements, and three supplemental trials or measurements: First, we tried to pass various sizes of steel balls down each lumen in order from the smallest (3 mm) to largest (4.5 mm). If the ball passed on the first attempt, we tried just once; otherwise, we made a second attempt. Second, we measured the external diameter of tracheal and bronchial cuff using a profile projector. Third, we measured the length of the cuff and tip of the bronchial segment of the tubes using the profile projector. Fourth, we measured various lengths of the tubes. Fifth, we measured the external diameter of both lumens and the tubules for tracheal and bronchial cuff inflation. Finally, we measured various cross-sectional areas including the tracheal lumen, bronchial lumen, and tubules for cuff inflation. We also conducted three supplemental studies. First, we measured air volume in the cuff when intracuff pressure equaled 2 or 3 kPa. Second, we defined the configuration of the tracheal and bronchial cuffs. Third, we defined the presence or absence of bevels and also measured the angle of the bevels using the profile projector.ResultsWe performed nine trials and measurements and found large disparities between each manufacturer’s tubes.ConclusionsThe large disparities found between the measurements of the five manufacturers’ tubes may be due to different lots or changes in specifications made by each manufacturer. We found tubes exhibiting lower quality, such as deformations, and non-universal and inconsistent sizing, in the comparison of the manufacturers’ tubes. Practitioners should be aware of the features and aspects of these tubes.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12871-022-01698-2.

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.

ASSESSMENT OF ENDOTRACHEAL TUBE CUFF PRESSURE: FINGER PRESSURE TECHNIQUE VERSUS MINIMUM LEAK TECHNIQUE

Objective: The purpose of this study is to compare routinely used cuff insufflation techniques to finger-pressure and minimal leak procedures for achieving safe endotracheal tube (ETT) intracuff pressures in patients undergoing endotracheal intubation. Methods: It is a prospective observational study conducted in patients undergoing elective surgical procedures under general anaesthesia at GITAM Institute of Medical Sciences and Research, Visakhapatnam from January 2019 to June 2020. In Group FP, which includes 50 patients, the ETT cuff (ETTc) was inflated by palpating the pilot balloon between the index finger and thumb until it became taut. When this point was reached, the syringe was detached from the pilot balloon, and a cuff manometer was attached. The pressure reading on the cuff manometer is noted. In Group ML, which includes 50 patients, the ETTc was inflated fully, and then the air was withdrawn slowly from the cuff with auscultation over the trachea until a small leak was heard. When the point was reached, the syringe was detached, and a cuff manometer was attached; pressure readings were noted. Results: Mean inflation cuff pressure in the FP group was 45.40±21.74 cm H2O and in the ML group was 28.68±8.35 cm H2O. In Group FP, out of 50 patients, cuff pressure in 14 (28%) patients was in the normal range; in 32 (64%) patients, the cuff was over inflated, and in 4 patients (8%) cuff was under inflated. In the group ML, 24 (48%) patients have cuff pressure within the normal range; in 18 (36%) patients, the cuff has been over inflated, and 8 (16%) patients have low cuff pressures. Cuff pressure adjustment was required in 36 patients (72%) in the FP group, whereas 26 patients (52%) in the ML group. ML group has a low incidence of postoperative complications, i.e., 10%, compared to the FP group, i.e., 18%. A positive correlation was seen between the measured cuff pressure and body mass index, Volume of air insufflated. Conclusion: The main conclusion is to realize the need to use manometers or better-automated controllers during routine anaesthetic procedures.

Intraoperative Evaluation of Effects of Different Gas Mixtures (Oxygen 100%, O2 50%:N2O 50%, Air on Cuff Pressure of PLMA (Proseal LMA)

Introduction:- we study the intra operative evaluation of different gas mixture(oxygen 100%, O2 50%:N2O 50%, AIR on cuff pressure of PLMA. Aims and Objectives:- To study intracuff pressure changes and the change in final volume of gas mixture during inflation and deflation during intraoperative period and postoperative complications. Material and Methods:- This double blind, prospective Study was conducted in Department of Anaesthesiology, Maharishi Markandeshwar Institute of Medical Sciences and Research, Mullana, Ambala following approval from institutional ethical committee and written informed patient consent. The sample size of 120 patient aged 18 to 60 years, belonging to ASA physical status 1 and 2 undergoing surgery in general anesthesia with PLMA as airway device divided into three group on the basis of PMLA cuff gas mixture:-Group O - oxygen 100%, Group ON - Nitrous 50%: Oxygen 50%, Group A – Air. Results and Conclusion:- Combination of N2O and O2 resulted in decreased intracuff pressure and air lead to a slight increase in intracuff pressure with O2 providing relatively stable cuff pressures. Keywords: PLMA,100% Oxygen, Air, Oxygen 50% N2O 50%, Air.