Subglottic Space Research Articles

Impact of multizonal decontamination of upper respiratory tract on incidence of ventilator-associated pneumonia: multicenter randomized pilot study

INTRODUCTION: Ventilator-associated pneumonia (VAP) is the one of nosocomial infections in intensive care units. VAP can result in prolonged duration of hospitalization and invasive mechanical ventilation (MV) that is associated with attributive mortality. OBJECTIVE: The aim of our pilot multicenter randomized study was to assess effect of the multizonal decontamination of upper airway including subglottic space on the VAP incidence and time of onset, as well as colonization upper airway and clinical outcomes. MATERIALS AND METHODS: Sixty patients requiring the prolonged MV were included in the prospective study. All participants were randomized into three groups: the control, the local antiseptic (LA) and the bacteriophage (BP). All patients were managed using similar VAP protective bundle. Infection-related ventilator-associated complications (IVAC) were registered based on clinical, laboratory, and instrumental examination. Diagnosis of VAP was confirmed if CPIS was ≥ 6 points. RESULTS: A total incidence of IVAC did nоt differ between groups: 15 (75 %), 14 (70 %), and 17 (85 %) cases in the control, LA, and BP groups, respectively. The VAP incidence was lower in the LA and BP groups compared with the controls: 3 (15 %) and 3 (15 %) vs 10 (50 %) cases (χ2 = 8.35; p = 0.015). The overall mortality was 30 % and did not differ between the groups. Multi-selective decontamination resulted in a trend to increased ventilator-associated tracheobronchitis incidence in the BP group and to silent colonization in both LA and BP groups (p = 0.07). No differences in the duration of MV, ICU and hospital stay were observed. CONCLUSIONS: The combined multizonal upper airway decontamination involving subglottic space is associated with a reduction of the VAP incidence but did not change the overall IVAC rate. Multizonal decontamination based on subglottic bacteriophage instillation might have a potential to influence the microbial heterogeneity of upper airways.

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.

Laryngoplasty with T-tube stenting in the treatment of subglottic stenosis in children

Introduction. Laryngeal stenosis is a congenital or acquired narrowing of the larynx that causes airway obstruction. Approximately 90% of cases of acquired subglottic stenosis in infants and children are due to endotracheal intubation. Laryngotracheoplasty with T-tube placement is a method for treating laryngotracheal stenosis.
 Aim. To demonstrate our experience of treating children with stenosis of the subglottic space using laryngoplasty with T-tube placement.
 Materials and methods. 53 patients with postintubation laryngeal stenosis are treating in the surgical thoracic department of the National Medical Research Center for Children's Health for the period from 2019 until now. All children were examined. 33 patients underwent laryngoplasty with T-tube stenting.
 Results. Nowadays, 18 children have been decannulated after laryngoplasty with T-tube stenting, the rest of the patients continue their treatment.
 Conclusion. According to our materials, T-tube stenting is safe and can be an alternative method for treating children with severe acquired laryngeal stenosis.

ESTROGEN AND PROGESTERONE RECEPTOR EXPRESSION IN TRACHEAL MUCOSA OF PATIENTS WITH IDIOPATHIC SUBGLOTTIC STENOSIS

TOPIC: Lung Pathology TYPE: Original Investigations PURPOSE: Idiopathic subglottic stenosis (iSGS) is the narrowing of subglottic space without antecedent injury or identifiable disease process, that leads to airway stenosis. The causative mechanism and pathogenesis remains unclear. The purpose of this pilot study is to evaluate the role of estrogen and progesterone in the pathophysiology of iSGS as it almost exclusively effects females. METHODS: We performed a prospective case control study of patients with iSGS undergoing endoscopic dilation procedures. Patients were identified using the departmental registry for iSGS patients. Patients without a diagnosis of iSGS undergoing bronchoscopy for non-dilation procedures served as controls and iSGS patients served as self controls. Endobronchial forceps biopsies were obtained from the stenotic area in iSGS patients and normal tracheal mucosa distal to the stenotic area. In controls, endobronchial forceps biopsies were obtained from normal tracheal mucosa. The specimens were stained for estrogen alpha and progesterone receptors.We assessed the estrogen alpha and progesterone receptor status of the specimens with plans for estrogen beta testing in the future. We avoided direct comparison due to relatively small numbers. RESULTS: Histological samples of 13 patients with iSGS and 7 controls were evaluated (Table 1). Patients with iSGS had undergone at least 1 endoscopic dilation prior to inclusion. 7 patients were included as controls, 3/7 with sarcoidosis, 3/7 with suspected lung cancer and 1/6 with tracheobronchomalacia.Significantly more fibrosis and chronic inflammation was identified in the iSGS specimens compared with the non-stenotic areas and control samples (Table 1). Mucosal ulceration and acutely inflamed granulation tissue (5 of 13 patients), squamous metaplasia (9 of 13 patients), were seen only in stenotic areas. Samples from the patient’s normal mucosa expressed mild and moderate estrogen alpha (90%). In contrast 61% of the peri-stenotic samples were negative. The PR expression showed moderate and high expression in the biopsies of non-involved areas (87.5%), but was significantly decreased to no or low levels (90%) in the peri-stenotic samples. In each patient, the expression of ER alpha and progesterone receptors were decreased in the peri- stenotic compared with the non-stenotic areas. CONCLUSIONS: The predilection of iSGS for premenopausal females is suggestive of hormonal causality. This pilot study suggests that iSGS patients may have higher levels of hormone receptors, compared with the general population. In addition, the expression of hormone receptors, especially progesterone, is decreased in the peri-stenotic areas. Further studies with a larger population are needed to identify the role of hormones, and potential use of hormone receptor therapy for altered expression of these receptors. DISCLOSURES: No relevant relationships by Valentina Robila, source=Web Response No relevant relationships by javeryah safi, source=Web Response Consultant relationship with COOK medical Please note: $1001 - $5000 by Ray Shepherd, source=Web Response, value=Consulting fee Royalties - authorship relationship with UpToDAte Please note: $1001 - $5000 by Ray Shepherd, source=Web Response, value=Royalty grant for industry study relationship with Olympus Spiration Please note: $1001 - $5000 by Ray Shepherd, source=Web Response, value=Grant/Research Support

Endoscopic treatment of subglottic stenosis in children

Introduction. Subglottic stenosis is one of the most common causes of upper airway obstruction. The incidence of post-intubation stenosis ranges from 0.9% to 3% (Rodríguez H. et al.), or from 0.2% to 20% (Haranal M.Y. et al.). Currently, there is no consensus on the choice of surgical tactics due to a large number of modalities for surgical restoration of the laryngeal lumen.Material and methods. 44 patients with postintubation laryngeal stenosis were treated in the surgical thoracic department of the National Medical Research Center of Children’s Health subordinate to the Ministry of Health of the Russian Federation during 2019-2021. The average age of patients in this group was 4 years 8 months ± 3 years 8 months. Endoscopic treatment was done to 24 patients (54.5%). Laryngoscopy, fibrobronchoscopy, multispiral computed tomography and, if necessary, barium esophagogram were done for additional diagnostics.Results. The average number of endoscopic procedures per patient was 2.9 ± 1.5 (range from 1 to 7). Good results were seen in 20 patients (83.3%).Conclusions. Endoscopic techniques are alternative options to open reconstructive surgery. These techniques give good results in treating stenoses in the subglottic space and give a good chance to avoid tracheostomy in a certain group of patients, which, according to the results of our study, was as large as 79.1%.

Therapeutic effectiveness of costal cartilage grafting into both anterior and posterior walls for laryngotracheal reconstruction in acquired subglottic stenosis.

We have reviewed the surgical procedures performed and outcomes for low-birth-weight infants with acquired subglottic stenosis. The gestational age at birth, birth weight, age at Laryngotracheal reconstruction, and therapeutic outcome over the past 26years were reviewed. Laryngotracheal reconstruction was initially performed by costochondral grafting involving only the anterior wall for the first operation, but since 2010 a costal cartilage was also inserted into the posterior wall of the cricoid cartilage using the BENSON pylorus spreader to split the cartilage. There were 21 patients. The mean gestational age was 29.6weeks, the mean birth weight was 1127g, and the first surgery was performed at a mean age of 37.0 ± 21.8months. Extubation was possible in 11 of 21 patients (52.3%) after the first surgery and in 7 of 7 patients after re-operation. The total extubation rate reached 100% (18/18) excluding three patients (one who suffered sudden death, and two who were lost to follow-up). Sufficient dilatation of the subglottic space could not be achieved by costochondral grafting involving the anterior wall alone. The extubation rate was improved by dilatation of the posterior wall and the insertion of costal cartilage into both the anterior and posterior walls.

A Case of Subglottic Edema Developed After Intubation with a Double-Lumen Endotracheal Tube

An 80-year-old woman underwent video-assisted thoracoscopic surgery (VATS) for lung cancer. The patient was intubated preoperatively with a 32 Fr DLT. However, since it was difficult to pass the tube through the subglottic space, the tube size was changed to 28 Fr. One day later, the patient complained of hoarseness. Fiberoptic laryngoscopic examination revealed subglottic stenosis caused by mucosal edema. Emergency tracheostomy was performed under local anesthesia. By 18 days after the VATS, the subglottic stenosis had completely resolved.

Prevention of ventilator-associated pneumonia in intensive departments from the nursing perspective

Ventilator-associated pneumonia (VAP) pose a serious nosocomial infection for patient at intensive care unit. Important role in its prevention presents nurse, who provides care for ventilated patient. This report drives attention to preventive aspects of VAP from nurse’s perspective, as is cleanse of oral cavity, airways maintenance, drainage of subglottic space, head position of patient on mechanical ventilator. We point to present recommendations and studies, which cover VAP prevention.

Selective digestive decontamination solution used as \u201clock therapy\u201d prevents and eradicates bacterial biofilm in an in vitro bench-top model

BackgroundMost preventing measures for reducing ventilator-associated pneumonia (VAP) are based mainly on the decolonization of the internal surface of the endotracheal tubes (ETTs). However, it has been demonstrated that bacterial biofilm can also be formed on the external surface of ETTs. Our objective was to test in vitro the efficacy of selective digestive decontamination solution (SDDs) onto ETT to prevent biofilm formation and eradicate preformed biofilms of three different microorganisms of VAP.MethodsWe used an in vitro model in which we applied, at the subglottic space of ETT, biofilms of either P. aeruginosa ATCC 15442, or E. coli ATCC 25922, or S. aureus ATCC 29213, and the SDDs at the same time (prophylaxis) or after 72 h of biofilm forming (treatment). ETT were incubated during 5 days with a regimen of 2 h-locks. ETT fragments were analyzed by sonication and confocal laser scanning microscopy to calculate the percentage reduction of cfu and viable cells, respectively.ResultsMedian (IQR) percentage reduction of live cells and cfu/ml counts after treatment were, respectively, 53.2% (39.4%—64.1%) and 100% (100%–100.0%) for P. aeruginosa, and 67.9% (46.7%–78.7%) and 100% (100%–100.0%) for E. coli. S. aureus presented a complete eradication by both methods. After prophylaxis, there were absence of live cells and cfu/ml counts for all microorganisms.ConclusionsSDDs used as “lock therapy” in the subglottic space is a promising prophylactic approach that could be used in combination with the oro-digestive decontamination procedure in the prevention of VAP.

Impact of Subglottic Saline Irrigation on Reducing Bacterial Contamination for Oral Surgery Patients.

This study investigated the effectiveness of subglottic irrigation (SI) with 100 mL of saline on reducing bacterial contamination in the subglottic space during oral surgery procedures without the use of throat packs. Subglottic lavage and irrigation were performed through the suction lumen located on specialized endotracheal tubes (ETTs) with capabilities of permitting evacuation from the subglottic space. Fifty-three patients who were scheduled for oral surgery procedures under general anesthesia while intubated with specialized ETTs at Kyushu Dental University Hospital were enrolled in this study. Subglottic irrigation was performed, and the sample fluid was collected through the ETT suction lumen for smear and culture bacterial examinations after 3 points in time: immediately after intubation, after completing the surgical procedure, and again after SI. Oral surgery without a throat pack significantly increased bacterial contamination in the subglottic lavage (p < .001), and SI decreased bacterial contamination (p < .001) similarly to levels found after tracheal intubation. Subglottic irrigation with 100 mL of saline was effective in reducing bacterial load in the subglottic space to levels similarly noted immediately after intubation for patients undergoing intraoral surgical procedures without the use of a throat pack.

Effect of using the Suction Above Cuff Endotracheal Tube (SACETT) on postoperative respiratory complications in rhinoplasty: a randomized prospective controlled trial.

Background: The Suction Above Cuff Endotracheal Tube (SACETT) has a dorsal port above the cuff designed to enable the continuous or intermittent suctioning of secretions from the subglottic space. Thus, it facilitates the suctioning of excessive secretions above the cuff and around the glottis.Objectives: In this study, we investigated the effect of the using the SACETT on laryngospasm and postoperative complications in rhinoplasty operations.Methods: This randomized controlled clinical trial enrolled 132 patients undergoing rhinoplasty. The patients were randomly divided into two groups: Suction above Cuff Endotracheal Tube (n=66; Group SA) and classic endotracheal tube (n=66; Group C). Complications following general anesthesia were statistically analyzed among the two groups.Results: The incidence of postoperative laryngospasm (p=0.02) and respiratory complications was found to be lower in Group SA than in Group C. In addition, the incidence of agitation (p=0.035), postoperative nausea, and vomiting (PONV) (p=0.041), which required antiemetic drug administration, swallowing difficulty (p=0.012), and sore throat (p=0.027) were found to be lower in Group SA than in Group C.Conclusion: We suggest that using the SACETT in rhinoplasty reduces the incidence of postoperative respiratory complications as well as the incidence of agitation, sore throat, swallowing difficulty, and PONV.Clinical Trial Number: NCT03584503

The functional outcomes of open vertical resections of the larynx

The early diagnostics of the malignant tumours of the larynx provides a basis for the timely beginning of their conservative treatment and endolaryngeal surgical interventions. However, neither the conservative treatment nor endolaryngeal surgery ensures the sufficiently efficient treatment when the tumour spreads over the anterior commissure, subglottic space, and/or laryngeal ventricles. The open surgical resection of the larynx is indicated for the management of the patients presenting with this condition. Our experience is based on the performance of vertical resection of the larynx in 98 patients including the fronto-lateral and extended fronto-lateral interventions in 63 and 35 of them, respectively. The formation of the malignant tumour is known to result in the alteration of the acoustic characteristics of the patient's voice as compared to the initially normal ones in the preceding period. Specifically, the mean values of the fundamental tone frequency increases, the intensity of the sound signal decreases, and the amplitudes of the fundamental tone harmonics tend to be reduced. At the same time, both the dispersion and the variability of the acoustic characteristics being studied undergo an enhancement in comparison with the normal values. Open resection of the larynx with its simultaneous endoscopic correction made it possible to restore the respiratory and vocal functions in 90.8% and 92.1% of the treated patients respectively.

Serial intralesional triamcinolone acetonide injections for acquired subglottic stenosis in premature infants.

Long-term intubation of premature infants sometimes induces acquired subglottic stenosis (SGS), causing glottic or supraglottic problems. These kinds of SGS often require tracheostomy and subsequently make decannulation difficult. The aim of our study was to clarify the efficacy of repeated intralesional steroid injections to the stenosis. Six children with acquired SGS, who were treated with triamcinolone acetonide injections to the subglottic space just below the vocal folds between September 2015 and December 2017 were retrospectively reviewed. The patients' mean age was 4.3 (range 1.3-4.4) years, the mean gestational age at birth was 25 (23-28) weeks, and the mean birth weight was 591 (456-734) g. The degree of SGS was grade II in one patient and III in five patients, with both tracheostoma and glottic or supraglottic abnormalities. They generally underwent ten procedures, every 3-4 weeks. In most cases, the patency of the injected space improved by 25-220%, and the symptoms were relieved. One patient achieved decannulation, and another one underwent laryngotracheal reconstruction and decannulation. Two patients started using a speech cannula. There were no severe complications. Serial intralesional steroid injections are likely to be effective in improving the patency of acquired SGS.

The Relationship Between Postoperative Pneumonia and Endotracheal Suctioning Under General Anesthesia in Ophthalmic Surgery: A Retrospective Study.

Postoperative pneumonia is the third most common postoperative complication. It may result from aspiration of secretions accumulating in the subglottic space during general anesthesia (GA). However, the relationship between endotracheal suctioning (ETS) during extubation from GA emergence and postoperative pneumonia has not been well investigated. Therefore, the aim of this study was to investigate the effectiveness of ETS during extubation in prevention of postoperative pneumonia in ophthalmic surgery under GA in our medical center from 2011 through 2015. Three thousand, seven hundred and ninety-four patients receiving ophthalmic surgery under GA were included and divided into two groups by the anesthesiologists. The first group underwent the conventional ETS during extubation, while the other group was extubated without ETS. The incidences of postoperative pneumonia were compared between the two groups to find the correlation between ETS during extubation and postoperative pneumonia. In addition, other complication such as postoperative hemorrhage was also recorded. Of the 3,794 patients undergoing ophthalmic surgery under GA, 2,187 (58%) patients underwent extubation with ETS, whilst 1,607 (42%) patients were extubated without ETS. The incidence rates of postoperative pneumonia with or without ETS during extubation were both 0%. Besides, the incidence rates of postoperative hemorrhage were also both 0% in two groups. Extubation from GA without ETS seemed not to increase the risk of postoperative pneumonia. Thus, no routine ETS during extubation seemed not to be a risk factor for postoperative pneumonia under GA in ophthalmic surgery.

Orotracheal tube as arisk factor for lower respiratory tract infection: preliminary data from arandomised trial.

The aim of the study was to investigate whether polyurethane (PU) endotracheal tubes, continuous measurements of cuff pressure and aspiration of the subglottic space as a bundle of parameters could reduce patients' risk for developing ventilator associated pneumonia (VAP). Two groups of patients that differed only in terms of endotracheal tubes and intubation intervention were compared. GroupA was ventilated using PU tubes a with conical cuff; they also had continuous cuff pressure measurement and continuous subglottic aspiration. GroupB was ventilated using PVC tubes with a cylindrical cuff; the patients underwent intermittent cuff pressure measurement and intermittent subglottic aspiration. Seven patients in groupA (13.2%) and 18 in groupB (36.0%) out of 103 were diagnosed with VAP. VAP patients were in general older, stayed longer in the ICU and were ventilated significantly longer compared with the patients with no VAP. Eight more patients in groupB died compared with groupA. Moreover, subjects in groupA survived longer. Patient age, hours on mechanical ventilation, and days on an ICU were all positively associated with the occurrence of VAP. Prevention parameters in ventilation (PU cuff, conical cuff, continuous subglottic drainage and continuous cuff pressure measurement) could prevent the incidence of VAP in ICU patients.

Inter-rater and intra-rater reliability of the airway diameter measured by sonography.

Sonography has gained a broad field of applications in current anesthetic practice. During airway management, it could have an important role, because it allows real-time measurement of anatomical aspects and a functional evaluation with high safety profile. However, assessment of the reliability and precision of these measurements is critical if sonography is used as a clinical diagnostic tool. The aim of the study was to estimate inter-rater and intra-rater reliability of the airway diameter measured by sonography in heathy volunteers. We conducted a cross-sectional study during 2015 on healthy adult volunteers. Using sonography, transverse internal diameter of subglottic space was measured twice by two blinded sonographers. Agreement was classified as very good for intra-rater measurements (ICC=0.84) and good for the inter-rater measurements (ICC=0.71). The 95% CI of agreement limits for the intra-rater measurements were inferior to those for the inter-rater measurements. Ultrasound measurement is a reliable and precise method to measure the internal subglottic diameter of the airway. Ultimately, this method may provide clinicians valuable information regarding airway diameter in adults and may help to guide treatment options.

Eradication of P. aeruginosa biofilm in endotracheal tubes based on lock therapy: results from an in vitro study

BackgroundDespite the several strategies available for the management of biofilm-associated ventilator-associated pneumonia, data regarding the efficacy of applying antibiotics to the subglottic space (SS) are scarce. We created an in vitro model to assess the efficacy of antibiotic lock therapy (ALT) applied in the SS for eradication of Pseudomonas aeruginosa biofilm in endotracheal tubes (ETTs).MethodsWe applied 2 h of ALT to a P. aeruginosa biofilm in ETTs using a single dose (SD) and a 5-day therapy model (5D). We used sterile saline lock therapy (SLT) as the positive control. We compared colony count and the percentage of live cells between both models.ResultsThe median (IQR) cfu counts/ml and percentage of live cells in the SD-ALT and SD-SLT groups were, respectively, 3.12 × 105 (9.7 × 104-0) vs. 8.16 × 107 (7.0 × 107-0) (p = 0.05) and 53.2% (50.9%-57.2%) vs. 91.5% (87.3%-93.9%) (p < 0.001). The median (IQR) cfu counts/ml and percentage of live cells in the 5D-ALT and 5D-SLT groups were, respectively, 0 (0-0) vs. 3.2 × 107 (2.32 × 107-0) (p = 0.03) and 40.6% (36.6%-60.0%) vs. 90.3% (84.8%-93.9%) (p < 0.001).ConclusionWe demonstrated a statistically significant decrease in the viability of P. aeruginosa biofilm after application of 5D-ALT in the SS. Future clinical studies to assess ALT in patients under mechanical ventilation are needed.

Incidence of airway complications in patients using endotracheal tubes with continuous aspiration of subglottic secretions

BackgroundContinuous aspiration of subglottic secretions is effective in preventing ventilator-associated pneumonia, but it involves a risk of mucosal damage. The main objective of our study was to determine the incidence of airway complications related to continuous aspiration of subglottic secretions.MethodsIn consecutive adult patients with continuous aspiration of subglottic secretions, we prospectively recorded clinical airway complications during the period after extubation. A multidetector computed tomography of the neck was performed during the period of 5 days following extubation to classify subglottic and tracheal lesions as mucosal thickening, cartilage thickening or deep ulceration.ResultsIn the 86 patients included in the study, 6 (6.9%) had transient dyspnea, 7 (8.1%) had upper airway obstruction and 18 (20.9%) had dysphonia at extubation. Univariate analysis identified more attempts required for intubation (2.3 ± 1.1 vs. 1.2 ± 0.5; p = 0.001), difficult intubation (71.4 vs. 10.1%, p = 0.001) and Cormack score III–IV (71.4 vs. 8.8%; p < 0.001) as risk factors for having an upper airway obstruction at extubation. The incidence of failed extubation among patients after planned extubation was 18.9% and 11 patients (12.7%) required tracheostomy. A multidetector computed tomography was performed in 37 patients following extubation, and injuries were observed in 9 patients (24.3%) and classified as tracheal injuries in 2 patients (1 cartilage thickening and 1 mild stenosis with cartilage thickening) and as subglottic mucosal thickenings in 7 patients.ConclusionsThe incidence of upper airway obstruction after extubation in patients with continuous aspiration of subglottic secretions was 8.1%, and the injuries observed by computed tomography were not severe and located mostly in subglottic space.

Infrared Red Intubation System (IRRIS) guided flexile videoscope assisted difficult airway management.

Tracheal intubation with a flexible scope is a cornerstone technique in patients with severely difficult airways, but may fail. We report on a technique, Infrared Red Intubation System (IRRIS), that seems to facilitate the identification of the glottis. The IRRIS is placed over the patient's cricothyroid membrane and emits blinking infrared light through the patient's skin into the subglottic space. When a flexible videoscope (one that does not filter infrared light) is introduced into the airway, it will display this as a blinking white light emerging from the glottis, retrograde transillumination, showing the pathway to the trachea. We have introduced this as an adjunct when managing our patients with difficult airways. We describe the technique and retrospectively report on the first ten patients where it was used. All ten patients had significant pathology in the airway, radiation therapy, predictors for difficult intubation and/or morbid obesity. In all cases the blinking light was visible during the flexible endoscopy and provided unambiguous identification of the glottis, from a distance. The blinking nature of the light from the IRRIS helped to distinguish it from the reflections in the mucosa that inevitably arise when the mucosa is hit by the light from the flexible scope itself. The addition of the IRRIS technique to intubation with flexible videoscopes may be a tool that will make intubation of the most difficult airways easier and may be of special help to the clinician who only rarely uses flexible videoscopes for tracheal intubation.

Optimization of Endotracheal Tube Cuff Pressure by Monitoring CO2 Levels in the Subglottic Space in Mechanically Ventilated Patients: A Randomized Controlled Trial.

Many of the complications of mechanical ventilation are related to inappropriate endotracheal tube (ETT) cuff pressure. The aim of the current study was to evaluate the effectiveness of automatic cuff pressure closed-loop control in patients under prolonged intubation, where presence of carbon dioxide (CO2) in the subglottic space is used as an indicator for leaks. The primary outcome of the study is leakage around the cuff quantified using the area under the curve (AUC) of CO2 leakage over time. This was a multicenter, prospective, randomized controlled, noninferiority trial including intensive care unit patients. All patients were intubated with the AnapnoGuard ETT, which has an extra lumen used to monitor CO2 levels in the subglottic space.The study group was connected to the AnapnoGuard system operating with cuff control adjusted automatically based on subglottic CO2 (automatic group). The control group was connected to the AnapnoGuard system, while cuff pressure was managed manually using a manometer 3 times/d (manual group). The system recorded around cuff CO2 leakage in both groups. Seventy-two patients were recruited and 64 included in the final analysis. The mean hourly around cuff CO2 leak (mm Hg AUC/h) was 0.22 ± 0.32 in the manual group and 0.09 ± 0.04 in the automatic group (P = .01) where the lower bound of the 1-sided 95% confidence interval was 0.05, demonstrating noninferiority (>-0.033). Additionally, the 2-sided 95% confidence interval was 0.010 to 0.196, showing superiority (>0.0) as well. Significant CO2 leakage (CO2 >2 mm Hg) was 0.027 ± 0.057 (mm Hg AUC/h) in the automatic group versus 0.296 ± 0.784 (mm Hg AUC/h) in the manual group (P = .025). In addition, cuff pressures were in the predefined safety range 97.6% of the time in the automatic group compared to 48.2% in the automatic group (P < .001). This study shows that the automatic cuff pressure group is not only noninferior but also superior compared to the manual cuff pressure group. Thus, the use of automatic cuff pressure control based on subglottic measurements of CO2 levels is an effective method for ETT cuff pressure optimization. The method is safe and can be easily utilized with any intubated patient.