Comparison of two techniques of administering the Valsalva manoeuvre in patients under general anaesthesia: A randomised controlled study.

Background and Aims: Surgeons often request a Valsalva manoeuvre (VM) at the end of surgery (head-neck surgery, craniotomy) to check haemostasis and to unmask covert venous bleeders. We aimed to compare an anaesthesia machine-generated objective technique for delivering VM under pressure-control (PC) mode with the traditional subjective technique of delivering VM in manual mode. Methods: This randomised controlled study included 60 adult patients randomised to manual (Group M) and controlled ventilation (Group C) groups. Our primary outcome measure was internal jugular vein (IJV) diameter at pre-determined time points (T0 = baseline, T1 = VM initiation, T2 = 20 s after VM initiation, T3 = immediately after VM release, and T4 = 1 min, T5 = 2 min and T6 = 5 min post-VM release). Secondary outcome measures included mean arterial pressure (MAP), heart rate, time to desired plateau airway pressure, number of patients with bleeders unmasked and surgeon satisfaction. Independent/paired sample t-tests were applied. Results are expressed as mean (standard deviation), mean difference (95% confidence interval), dotted box-whisker plots and trendlines. P <0.05 is considered statistically significant. Results: Mean differences in diameter changes in IJV (in centimetres) in the mediolateral and anteroposterior directions between Group C and Group M were -0.136 (-0.227, -0.044) and -0.073 (-0.143, -0.002), respectively. VM in the PC mode produced more significant IJV dilatation (P = 0.004, P = 0.044). MAP at T0 and T1 was comparable. At T2 and T3, there was a more significant fall in MAP in Group C versus Group M (P = 0.018 and P = 0.021, respectively). At T4, T5 and T6, MAP was comparable. Conclusion: Performing VM in PC mode is a better technique based on IJV diameter, haemodynamics, bleeder unmasking and surgeon satisfaction.

Management of severe acute respiratory distress syndrome in Australia and New Zealand (SAGE-ANZ): An observational study.

Objective: Acute respiratory distress syndrome (ARDS) is associated with significant mortality, morbidity, and cost. We aimed to describe characteristics and management of adult patients admitted to intensive care units (ICUs) in Australia and New Zealand with moderate-severe ARDS, to better understand contemporary practice. Design: Bi-national, prospective, observational, multi-centre study. Setting: 19 ICUs in Australia and New Zealand. Participants: Mechanically ventilated patients with moderate-severe ARDS. Main outcome measures: Baseline demographic characteristics, ventilation characteristics, use of adjunctive support therapy and all-cause mortality to day 28. Data were summarised using descriptive statistics. Results: 200 participants were enrolled, mean (±SD) age 55.5 (±15.9) years, 40% (n = 80) female. Around half (51.5%) had no baseline comorbidities and 45 (31%) tested positive for COVID-19. On day 1, mean SOFA score was 9 ± 3; median (IQR) PaO2/FiO2 ratio 119 (89, 142), median (IQR) FiO2 70% (50%, 99%) and mean (±SD) positive end expiratory pressure (PEEP) 11 (±3) cmH2O. On day one, 10.5% (n = 21) received lung protective ventilation (LPV) (tidal volume ≤6.5 mL/kg predicted body weight and plateau pressure or peak pressure ≤30 cm H2O). Adjunctive therapies were received by 86% (n = 172) of patients at some stage from enrolment to day 28. Systemic steroids were most used (n = 127) followed by neuromuscular blockers (n = 122) and prone positioning (n = 27). Median ventilator-free days (IQR) to day 28 was 5 (0, 20). In-hospital mortality, censored at day 28, was 30.5% (n = 61). Conclusions: In Australia and New Zealand, compliance with evidence-based practices including LPV and prone positioning was low in this cohort. Therapies with proven benefit in the treatment of patients with moderate-severe ARDS, such as lung protective ventilation and prone positioning, were not routinely employed.

Prospective Evaluation of Extubation Failure in Neonates and Infants After Cardiac Surgery.

Background: Extubation failure and its associated complications are not uncommon after pediatric cardiac surgery, especially in neonates and young infants. We aimed to identify the frequency, etiologies, and clinical characteristics associated with extubation failure after cardiac surgery in neonates and young infants. Methods: We conducted a single center prospective observational study of patients ≤180 days undergoing cardiac surgery between June 2022 and May 2023 with at least one extubation attempt. Patients who failed extubation, defined as reintubation within 72 h of first extubation attempt, were compared with patients extubated successfully using χ2, Fisher exact, or Wilcoxon rank-sum tests as appropriate. Results: We prospectively enrolled 132 patients who met inclusion criteria, of which 11 (8.3%) failed extubation. Median time to reintubation was 25.5 h (range 0.4-55.8). Extubation failures occurring within 12 h (n = 4) were attributed to upper airway obstruction or apnea, whereas extubation failures occurring between 12 and 72 h (n = 7) were more likely to be due to intrinsic lung disease or cardiac dysfunction. Underlying genetic anomalies, greater weight relative to baseline at extubation, or receiving positive end expiratory pressure (PEEP) > 5 cmH2O at extubation were significantly associated with extubation failure. Conclusions: In this study of neonates and young infants recovering from cardiac surgery, etiologies of early versus later extubation failure involved different pathophysiology. We also identified weight relative to baseline and PEEP at extubation as possible modifiable targets for future investigations of extubation failure in this patient population.

Towards an improved wind effect assessment for asbestos abatement: A methodology for reduced-scale experiments.

During building renovation or demolition, asbestos fibers can be released which can contaminate the environment, leading to potential occupational health and public health concerns. Strict asbestos abatement procedures and regulations are in place to mitigate this risk, which involve sealing the worksite and depressurizing it relative to the outdoor environment (i.e., indoor pressure lower than the outdoor pressure) using mechanical ventilation. However, the depressurization of the containment can be breached by the effects of the wind. Hence, it is essential to identify which wind conditions are problematic and how to prevent their effects. To conduct corresponding laboratory measurements, it is first required to scale down the building and its containment zone including a working mechanical ventilation system. This paper presents an innovative methodology for conducting reduced-scale experiments on buildings equipped with mechanical ventilation systems for contaminant containment. The methodology, here explained in the context of asbestos abatement, could also be applied to any other type of particulate pollutant. The methodology of this research study includes the design of a mechanical ventilation system for depressurization; a method to scale down the building and the ventilation system for testing in a wind tunnel; and 3D steady Reynolds averaged Navier-Stokes (RANS) simulations for optimizing the positioning of the ventilation components. The methodology is applied for a single-zone building including its ventilation system, which is found to achieve the targeted indoor depressurization of -40 Pa, making it ready for wind tunnel tests.

Evaluation of lung homogeneity in neonates and small infants during general anaesthesia using electrical impedance tomography: a prospective observational study.

Background: Prolonged mechanical ventilation can create heterogeneous ventilation patterns, which increase the risk of lung injury in infants. However, little is understood about the risk of brief exposure to mechanical ventilation during anaesthesia. The aim of this prospective observational study was to describe the regional pattern of lung ventilation during general anaesthesia in healthy neonates and infants, using electrical impedance tomography. Methods: Twenty infants (age 3 days to 12 months), without known lung disease and receiving general anaesthesia with endotracheal intubation for supine positioned surgery, were included in the study. Anaesthesia and ventilation management was at the discretion of the treating clinician. Standardised lung imaging using electrical impedance tomography was made at six time points during anaesthesia from induction to post-extubation. At each time point, the gravity-dependent and right-left lung centre of ventilation was calculated. Results: Tidal ventilation favoured the dorsal lung regions at induction, with a median (inter-quartile range) centre of ventilation (CoV) of 58.2 (53.9-59.3)%. After intubation, there was a redistribution of ventilation to the ventral lung, with the greatest change occurring early in surgery: CoV of 53.8 (52.3-55.2)%. After extubation, CoV returned to pre-intubation values: 56.5 (54.7-58)%. Across all time points, the pattern of ventilation favoured the right lung. Conclusions: General anaesthesia creates heterogenous patterns of ventilation similar to those reported during prolonged mechanical ventilation. This potentially poses a risk for lung injury that may not be recognised clinically. These results suggest the need to better understand the impact of general anaesthesia on the developing lung. Clinical trial registration: Australian New Zealand Clinical Trials Registry (ACTRN 12616000818437, 22 June 2016).

A novel application of the Hyperflex™ tracheostomy tube for lung isolation in a patient with airway stoma after laryngectomy.

In patients who have undergone laryngectomy followed by permanent tracheostomy, managing the airway for one-lung ventilation during lung surgery may present a challenge for anaesthetists. This case report discusses a 45-year-old man with a permanent tracheostomy after a laryngectomy performed for laryngeal carcinoma 5 years ago. He was scheduled to undergo excision of a right bronchial mass for which one-lung ventilation was required. An adjustable Flange Hyperflex™ Tracheostomy tube (Bivona® Silicone Tracheostomy tube, Smiths Medical ASD, Inc., Gary, Indiana, USA) was used for this purpose and the tube was guided into the left main bronchus with a bronchoscope. Appropriate lung isolation was achieved using this technique, and there were no airway-related complications during or after the surgery. This case report shows that a Hyperflex™ tracheostomy tube can be successfully utilised in challenging airway scenarios in patients with a tracheostomy, where other options may not be feasible.

Navigating the Anesthetic Challenges of Vertebral Defects, Anorectal Anomalies, Cardiac Anomalies, Tracheoesophageal Fistula (TEF)/Esophageal Atresia, Renal Anomalies, and Limb Abnormalities (VACTERL) Association: A Delicate Balancing Act.

Vertebral defects, anorectal anomalies, cardiac anomalies, tracheoesophageal fistula (TEF)/esophageal atresia, renal anomalies, and limb abnormalities (VACTERL) association is a rare congenital disorder presenting with a constellation of birth defects. The diagnosis is primarily clinical, and patients exhibit at least three of these anomalies. These patients' management involves a multidisciplinary approach tailored to the individual's condition. Anesthetic management is particularly challenging due to the diverse and complex anomalies. This article discusses the anesthetic management of a term newborn male (39 weeks, six days gestation, 3340 g) diagnosed with VACTERL association. The newborn was admitted to the neonatal intensive care unit (NICU) and scheduled for the surgical repair of TEF and derivative colostomy on the second day of life. To mitigate the risk of air leak and abdominal distension from positive pressure ventilation, a derivative colostomy was performed first under regional anesthesia preserving spontaneous ventilation. To achieve that, the patient was sedated with ketamine and dexmedetomidine, and an ultrasound-guided single-shot caudal block with ropivacaine was performed. Post-abdominal decompression, general anesthesia was induced, and intubation was managed via videolaryngoscopy. Thoracoscopic TEF repair required several pauses for ventilation and hemodynamic optimization. Dopamine was administered intraoperatively for blood pressure support. The newborn was extubated and started on enteral feeding by the seventh postoperative day, progressing well by the time of discharge. In this case, a derivative colostomy before TEF repair avoided positive pressure ventilation complications. Ultrasound-guided caudal block provided effective regional anesthesia with high success rates. Ketamine and dexmedetomidine offered balanced sedation with minimal respiratory compromise. Dopamine was used effectively to maintain adequate perfusion, monitored with invasive blood pressure and cerebral oximetry. Anesthetic management of newborns with VACTERL association undergoing simultaneous repair of TEF and anal atresia demands meticulous and tailored planning to address the specific needs and minimize associated risks. This case highlights the importance of comprehensive anesthetic management and its impact on the patient's outcome.

[Tracheotomy : Indication and implementation]. / Tracheotomie : Indikation und Durchführung.

Tracheotomy has long been performed outside of intensive care medicine. In modern medicine, it has a firm place in the management of critically ill and emergency care patients as well as in cancer surgery of the head and neck, the care of long-term ventilated patients, patients with swallowing disorders, and neurological diseases. The indication, technique, and timing of tracheotomy are very different for the various diseases. This article provides an overview of the different indications, surgical techniques, and timing of tracheotomy in modern intensive care medicine.

Glucagon-like peptide-1 receptor agonists may benefit cardiopulmonary outcomes in patients with COPD.

BACKGROUND: Clinical studies have shown that glucagon-like peptide-1 receptor agonists (GLP-1 RA) can have beneficial effects on cardiopulmonary function. We conducted this longitudinal cohort study to compare the risk of cardiopulmonary outcomes and mortality between GLP-1 RA use and no use in patients with type 2 diabetes (T2D) and chronic obstructive pulmonary disease (COPD). METHODS: The study identified 8060 matched GLP-1 RA users and non-users from Taiwan's National Health Insurance Research Database from 1 January 2008 to 31 December 2019. Cox proportional hazards models were used to determine the risk of cardiopulmonary outcomes between GLP-1 RA users and non-users. RESULTS: The mean follow-up time was 2.51 and 2.46 years for GLP-1 RA users and non-users, respectively. In the matched cohorts, GLP-1 RA users had a significantly lower risk of mortality (adjusted HR (aHR) 0.46, 95% CI 0.38 to 0.56), cardiovascular events (aHR 0.73, 95% CI 0.65 to 0.82), non-invasive positive pressure ventilation (aHR 0.66, 95% CI 0.47 to 0.93), invasive mechanical ventilation (aHR 0.64, 95% CI 0.51 to 0.8) and bacterial pneumonia (aHR 0.76, 95% CI 0.65 to 0.88) than GLP-1 RA non-users. The subsequent analyses for various subgroup and medication duration also showed that GLP-1 RA was associated with a significantly lower risk of mortality, cardiovascular events, ventilation support and bacterial pneumonia than non-GLP-1 RA. CONCLUSION: This nationwide cohort study showed that GLP-1 RA had a lower risk of cardiopulmonary outcomes and all-cause mortality than non-GLP-1 RA in patients with T2D and COPD. GLP-1 RA may help manage diabetes in people with COPD.

Assessing 129Xe multi-breath washout MRI response to elexacaftor/tezacaftor/ivacaftor intervention in pediatric CF.

BACKGROUND: Monitoring multiple-breath washout (MBW) of a xenon tracer using magnetic resonance imaging (MBW Xe-MRI) provides quantitative regional measures of gas washout (fractional ventilation, FV) and spatial ventilation heterogeneity (coefficient of variation, CoVFV) in pediatric CF lung disease, but has yet to be evaluated in an interventional setting. METHODS: 12 pediatric CF participants (median age 15.3 ± 2 years) completed MBW Xe-MRI, pulmonary function tests (PFTs) (spirometry, N2 MBW for lung clearance index (LCI)) and single-breath Xe-MRI ventilation defect percent (VDP) measurements at baseline and 1-month post-initiation of elexacaftor/tezacaftor/ivacaftor (ETI) therapy. FV maps were calculated from MBW Xe-MRI washout images, and CoVFV maps were derived from FV maps. Significant changes between visits were determined using a paired Wilcoxon signed-rank test. For correlations between absolute changes, Pearson's correlation was used. RESULTS: All measures changed significantly 1-month post-ETI therapy compared to baseline. For MRI metrics, median [IQR] VDP was significantly (P < 0.001) lower at 1 month (8.0 [3.7 12.4]) compared to baseline (17.8 [8.3 22.5]), FV was significantly (P < 0.05) higher at 1 month (0.42 [0.41 0.46]) compared to baseline (0.38 [0.33 0.44]), and CoVFV was significantly (P < 0.001) lower at 1 month (0.06 [0.05 0.07]) compared to baseline (0.09 [0.08 0.12]). Both absolute and relative differences in CoVFV and LCI were found to correlate highly (R = 0.92, P < 0.0001 and R = 0.91, P < 0.0001, respectively). CONCLUSIONS: Functional information derived from MBW Xe-MRI, particularly CoVFV, can be used to assess regional lung function in pediatric CF patients in an interventional setting and may be complementary to VDP and pulmonary function tests.

"To BAL or not to BAL, that is the question": Variations in smoke inhalation injury guidelines from burn units and centres in England, Scotland and Wales.

AIM: To evaluate variations in diagnostic criteria and management recommendations for smoke inhalation injury (SII) amongst the burn networks of England, Scotland, and Wales. METHODS: A descriptive cross-sectional study examining SII guidelines provided by adult burn units and centres in England, Scotland and Wales. RESULTS: All 16 adult burn units and centres responded. Fourteen (87.5 %) had guidelines. Due to sharing of guidelines, ten unique guidelines were assessed. Diagnostic criteria showed variability with no universal criterion shared amongst guidelines. Bronchoscopy was recommended by 90 % of guidelines, but the timing varied. The use of bronchoscopic scoring systems was recommended by four guidelines. Bronchoalveolar lavage (BAL) was recommended by four, with considerable variation in frequency and choice of lavage fluid. All guidelines advised at least one nebulised agent: heparin (n = 8); N-acetyl cysteine (NAC) (n = 8); or salbutamol (n = 8). All guidelines included advice on carbon monoxide poisoning; however, carboxyhaemoglobin (COHb) cut-off levels for treatment varied (5 % [n-4], 10 % [n = 3], 15 % [n = 1]). All recommended high-flow oxygen. Seven (70 %) guidelines offered guidance on cyanide poisoning. Reduced/altered consciousness was the only consistent diagnostic criterion. Five (50 %) guidelines provided intubation guidance, emphasising the role of a 'senior clinician' as the intubator. Ventilatory guidance appeared in eight guidelines, focusing on lung protective ventilation (n = 8); oxygenation goals (n = 3); and permissive hypercapnia (n = 3). Within lung-protective ventilation, advice on tidal volume (6, or 6-8 ml/kg) and plateau pressures (>30 cmH2O) were presented most commonly (n = 7). CONCLUSION: This study has outlined the substantial variations in guidance for the management of SII. The results underscore the need for a national guideline outlining a standardised approach to the diagnosis and management of SII, within the limitations of the current evidence.

Implementation of a Perioperative Lung Protective Ventilation Protocol for Robotic-Assisted Surgeries.

This project sought to educate providers on the benefits of lung protective ventilation (LPV), implement a LPV protocol in robotic surgery, and evaluate adherence to the protocol in the adult (≥ 18 years) robotic-assisted surgery population. This project used a pre/post quality improvement design with a retrospective chart review and periodic knowledge, attitude, and practice surveys over the course of 6 months. This project retrospectively reviewed electronic medical records to assess adherence to the LPV protocol. The type of surgery; ventilator settings including positive end-expiratory pressure, FiO2, tidal volume, SpO2, ventilator mode, compliance, driving pressure and peak pressure; patient height and weight; patient body mass index; and American Society of Anesthesiologists physical status classification were collected. Analyzed results compared baseline preeducation data and data collected at 3- and 6-months postimplementation. Adherence to the LPV protocol parameters of tidal volume (P < .001), respiratory rate (P = .014), and driving pressure (P < .001) within LPV limits improved with statistical significance from pre- to postimplementation. Provider confidence and knowledge increased from pre- to posteducation (P = .049). Adherence to a LPV protocol improved with education and information tools.

Influence of intra-abdominal pressure on ventilatory mechanical power delivery and respiratory driving pressure during laparoscopic cholecystectomy: A prospective cohort study.

Background and Aims: Pneumoperitoneum creation for laparoscopic surgery increases the intraabdominal pressure and causes alveolar atelectasis. We investigated the influence of an increase in intra-abdominal pressure (IAP) on ventilatory mechanical power (MP) delivery during pneumoperitoneum creation for laparoscopic cholecystectomy. Material and Methods: In a prospective cohort design, we enrolled 42 patients undergoing laparoscopic cholecystectomy. During pneumoperitoneum creation, the IAP was sequentially raised to three predefined IAP levels (8, 11 and 14 mmHg), keeping identical ventilatory settings (timepoints T1, T2, and T3). After that, positive end-expiratory pressure (PEEP) was sequentially raised from 5 to 8 to 11 cmH2O (timepoint T4 and T5). The primary outcome included ventilatory MP delivery at each timepoint. Other variables included respiratory driving pressure (DP), airway resistance (AR), and respiratory compliance (RC). Results: The MP increased linearly with a rise in IAP from T1 to T3 (r = 0.71, P < 0.001); the MP increased by 0.19 per unit rise in IAP (effect size 0.90, P < 0.001). A similar positive correlation was also observed between DP and IAP from T1 to T3 (r = 0.73, P < 0.001); the DP increased by 0.72 per unit rise in IAP (effect size 0.89, P < 0.001). The MP increased significantly on increasing PEEP from T3 to T5, while the DP decreased concomitantly (P < 0.001). The AR increased significantly from T1 to T3, while RC decreased concomitantly; vice-versa was observed at T4 and T5 (P < 0.001). Conclusions: The ventilatory MP delivery rises linearly with an increase in IAP. Targeting an IAP-guided MP level could be an attractive approach to minimize lung injury.

Cadaveric Study on the Safety of High-Flow Nasal Oxygen in Laser Microlaryngeal Surgery.

INTRODUCTION: High-flow nasal oxygen (HFNO), or transnasal humidified rapid-insufflation ventilatory exchange (THRIVE), is a technique providing apneic oxygenation and a degree of ventilation during microlaryngeal surgery. Its use with laser has been questioned due to concern for airway fire. For fire to occur, a triad of ignition source, oxidizer, and fuel source must be present. By using HFNO and eliminating an endotracheal tube (fuel source), it is hypothesized that airway fire risk is minimal. We tested this theory with human cadavers using HFNO with increasing levels of FiO2 while performing microlaryngeal laser surgery. METHODS: HFNO was placed on two cadavers, and oxygen was administered at incrementally increasing fraction of inspired oxygen (FiO2) concentrations (30%-100%). Laryngeal microsurgery was conducted with CO2 and KTP lasers applied for 30 s. Oxygen readings were taken at several anatomic locations along the body assessing oxygen concentrations in correlation with increasing FiO2 administration. RESULTS: The use of CO2 and KTP laser on cadaveric vocal folds produced char but no spark or airway fire at any of the tested oxygen concentrations. Apart from the mouth, there was minimal increase in oxygen levels at the surrounding anatomic sites despite elevating FiO2 levels. CONCLUSION: HFNO may be safe to use during microlaryngeal laser surgery. By eliminating the endotracheal tube as a fuel source, risk of airway fire may be negligible. Our study safely applied CO2 and KTP lasers for an uninterrupted 30 s with HFNO at 70 L/min and 100% FiO2 producing no spark or fire. LEVEL OF EVIDENCE: NA Laryngoscope, 2024.

Association of Previous Cardiac Surgery With Postoperative Pneumonia in Infants Undergoing Abdominal Operations: A Cohort Study.

BACKGROUND: Children with congenital heart disease (CHD) often require other, non-cardiac related surgical procedures following their initial cardiac surgery. After full or partial CHD repair, they remain at increased risk of postoperative complications. We examined the association of previous cardiac intervention (surgery or percutaneous catheterization intervention) with postoperative pneumonia in infants undergoing abdominal general surgery. METHODS: A 1:1 propensity score-matched study was conducted using a retrospective cohort of 104,820 infants (<12 months) who had general abdominal surgeries between 2012 and 2022 in U.S. hospitals participating in the National Surgical Quality Improvement Program. The primary outcome was postoperative pneumonia within 30 days. Secondary outcomes included unplanned reintubation, prolonged mechanical ventilation (>72 h), and extended hospital stay (>75th percentile for the study cohort). RESULTS: Of the study cohort, 9736 infants (9.3%) had previous cardiac interventions. In the propensity score-matched sample, infants with previous cardiac surgery had increased risks of postoperative pneumonia (1.3% vs 0.8%; adjusted relative risk [RRadj]: 1.64, 95% CI: 1.22, 2.18, p = 0.001), unplanned reintubation (57.8% vs 32.6%; RRadj: 1.77, 95% CI: 1.77, 1.85, p < 0.001), prolonged mechanical ventilation (5.0% vs 2.3%; RRadj: 2.14, 95% CI: 1.83, 2.52, p < 0.001), and prolonged hospital stays (61.0% vs 53.8%; RRadj: 1.13, 95% CI: 1.10, 1.17, p < 0.001). CONCLUSIONS: A history of previous cardiac intervention carries an increased risk of postoperative pneumonia, unplanned tracheal reintubation, prolonged mechanical ventilation, as well as longer hospital stays following intra-abdominal surgery. Clinicians should closely monitor these patients for respiratory complications after surgery. LEVEL OF EVIDENCE: II.

Effect of perioperative sigh ventilation on postoperative hypoxemia and pulmonary complications after on-pump cardiac surgery (E-SIGHT): study protocol for a randomized controlled trial.

BACKGROUND: Postoperative hypoxemia and pulmonary complications remain a frequent event after on-pump cardiac surgery and mostly characterized by pulmonary atelectasis. Surfactant dysfunction or hyposecretion happens prior to atelectasis formation, and sigh represents the strongest stimulus for surfactant secretion. The role of sigh breaths added to conventional lung protective ventilation in reducing postoperative hypoxemia and pulmonary complications among cardiac surgery is unknown. METHODS: The perioperative sigh ventilation in cardiac surgery (E-SIGHT) trial is a single-center, two-arm, randomized controlled trial. In total, 192 patients scheduled for elective cardiac surgery with cardiopulmonary bypass (CPB) and aortic cross-clamp will be randomized into one of the two treatment arms. In the experimental group, besides conventional lung protective ventilation, sigh volumes producing plateau pressures of 35 cmH2O (or 40 cmH2O for patients with body mass index > 35 kg/m2) delivered once every 6 min from intubation to extubation. In the control group, conventional lung protective ventilation without preplanned recruitment maneuvers is used. Lung protective ventilation (LPV) consists of low tidal volumes (6-8 mL/kg of predicted body weight) and positive end-expiratory pressure (PEEP) setting according to low PEEP/FiO2 table for acute respiratory distress syndrome (ARDS). The primary endpoint is time-weighted average SpO2/FiO2 ratio during the initial post-extubation hour. Main secondary endpoint is the severity of postoperative pulmonary complications (PPCs) computed by postoperative day 7. DISCUSSION: The E-SIGHT trial will be the first randomized controlled trial to evaluate the impact of perioperative sigh ventilation on the postoperative outcomes after on-pump cardiac surgery. The trial will introduce and assess a novel perioperative ventilation approach to mitigate the risk of postoperative hypoxemia and PPCs in patients undergoing cardiac surgery. Also provide the basis for a future larger trial aiming at verifying the impact of sigh ventilation on postoperative pulmonary complications. TRIAL REGISTRATION: ClinicalTrials.gov NCT06248320. Registered on January 30, 2024. Last updated February 26, 2024.

Association between inspired oxygen fraction and development of postoperative pulmonary complications in thoracic surgery: a multicentre retrospective cohort study.

BACKGROUND: Limited data exist to guide oxygen administration during one-lung ventilation for thoracic surgery. We hypothesised that high intraoperative inspired oxygen fraction during lung resection surgery requiring one-lung ventilation is independently associated with postoperative pulmonary complications (PPCs). METHODS: We performed this retrospective multicentre study using two integrated perioperative databases (Multicenter Perioperative Outcomes Group and Society of Thoracic Surgeons General Thoracic Surgery Database) to study adult thoracic surgical procedures using one-lung ventilation. The primary outcome was a composite of PPCs (atelectasis, acute respiratory distress syndrome, pneumonia, respiratory failure, reintubation, and prolonged ventilation >48 h). The exposure of interest was high inspired oxygen fraction (FiO2), defined by area under the curve of a FiO2 threshold > 80%. Univariate analysis and logistic regression modelling assessed the association between intraoperative FiO2 and PPCs. RESULTS: Across four US medical centres, 141/2733 (5.2%) procedures conducted in 2716 patients (55% female; mean age 66 yr) resulted in PPCs. FiO2 was univariately associated with PPCs (adjusted OR [aOR]: 1.17, 95% confidence interval [CI]: 1.04-1.33, P=0.012). Logistic regression modelling showed that duration of one-lung ventilation (aOR: 1.20, 95% CI: 1.03-1.41, P=0.022), but not the time-weighted average FiO2 (aOR: 1.01, 95% CI: 1.00-1.02, P=0.165), was associated with PPCs. CONCLUSIONS: Our results do not support limiting the inspired oxygen fraction for the purpose of reducing postoperative pulmonary complications in thoracic surgery involving one-lung ventilation.

Effect of ventilation mode on postoperative pulmonary complications among intermediate- to high-risk patients undergoing abdominal surgery: A randomized controlled trial.

BACKGROUND: The effect of different mechanical ventilation modes on pulmonary outcome after abdominal surgery remains unclear. We evaluated the effects of three common ventilation modes on postoperative pulmonary complications (PPCs) among intermediate- to high-risk patients undergoing abdominal surgery. METHODS: This randomized clinical trial enrolled adult patients at intermediate or high risk of PPCs who were scheduled for abdominal surgery. Participants were randomized to receive one of three modes of mechanical ventilation modes: volume-controlled ventilation (VCV), pressure-controlled ventilation (PCV), and pressure-control with volume-guaranteed ventilation (PCV-VG). Lung-protective ventilation strategy was implemented in all groups. The primary outcome was the incidence of a composite of pulmonary complications within the first 7 postoperative days. Pulmonary complications within 30 postoperative days, the severity grade of PPCs, and other secondary outcomes were also analyzed. RESULTS: A total of 1365 patients were randomized and 1349 were analyzed. The primary outcome occurred in 98 (21.8%) in the VCV group, 95 (22.1%) in the PCV group, and 101 (22.5%) in the PCV-VG group (P = 0.865). Additionally, there were no statistically significant differences among the three groups in terms of the incidence of pulmonary complications within postoperative 30 days, severity grade of PPCs, and other secondary outcomes. CONCLUSION: In intermediate- to high-risk patients undergoing abdominal surgery, the choice of ventilation mode did not affect the risk of PPCs. TRIAL REGISTRATION: Chinese Clinical Trial Registry, entry ChiCTR1900025880.

A Comparison of Conventional Rotating Method and Non-Rotating Method for Double-Lumen Tube Insertion Using a Customized Rigid J-Shaped Stylet for One-Lung Ventilation: A Randomized Controlled Trial.

Background: The conventional double-lumen tube (DLT) insertion method requires a rotatory maneuver that was developed using direct laryngoscopy and may not be optimal for video laryngoscopy. This study compared a new non-rotatory maneuver with the conventional method for DLT insertion using video laryngoscopy. Methods: Patients scheduled for thoracic surgery requiring one-lung ventilation were randomly assigned to either the rotating (R) or non-rotating (NR) method groups. All patients were intubated using a customized rigid J-shaped stylet, a video laryngoscope, and a left-sided silicone DLT. The conventional rotatory maneuver was performed in the R group. In the NR group, the stylet was inserted with its tip oriented anteriorly (12 o'clock direction) while maintaining the bronchial lumen towards the left (9 o'clock direction). After reaching the glottic opening, the tube was inserted using a non-rotatory maneuver, maintaining the initial orientation. The primary endpoint was the intubation time. Secondary endpoints included first-trial success rate, sore throat, hoarseness, and airway injury. Results: Ninety patients (forty-five in each group) were included. The intubation time was significantly shorter in the NR group compared to the R group (22.0 [17.0, 30.0] s vs. 28.0 [22.0, 34.0] s, respectively), with a median difference of 6 s (95% confidence interval [CI], 3-11 s; p = 0.017). The NR group had a higher first-attempt success rate and a lower incidence of sore throats. Conclusions: The non-rotatory technique with video laryngoscopy significantly reduced intubation time and improved first-attempt success rate, offering a viable and potentially superior alternative to the conventional rotatory technique.

Comparison of 3D UTE free-breathing lung MRI with hyperpolarized 129Xe MRI in pediatric cystic fibrosis.

PURPOSE: To compare phase-resolved functional lung (PREFUL) regional ventilation derived from a free breathing 3D UTE radial MRI acquisition to hyperpolarized 129Xe-MRI (Xe-MRI), conventional 2D multi-slice PREFUL MRI, and pulmonary function tests in pediatric cystic fibrosis (CF) lung disease. METHODS: Free-breathing 3D UTE and 2D multi-slice 1H MRI as well as Xe-MRI were acquired in 12 stable pediatric CF patients. Using PREFUL, regional ventilation (RVent) maps were calculated from the free-breathing data. Ventilation defect percentage (VDP) was determined from 3D and 2D RVent maps (2D VDPRVent and 3D VDPRVent, respectively) and Xe-MRI ventilation (VDPXe). VDP was calculated for the whole lung and for eight regions based on left/right, anterior/posterior, and superior/inferior divisions of the lung. Global and regional VDP was compared between the three methods using Bland-Altman analysis, linear mixed model-based correlation, and one-way analysis of variance and multiple comparisons tests. RESULTS: Global 3D VDPRVent, VDPXe, and 2D VDPRVent were all strongly correlated (all R2 > 0.62, p < 0.0001) and showed minimal, non-significant bias (all <2%, p > 0.05). Three dimensional and 2D VDPRVent significantly correlated to VDPXe in most of the separate lung regions (R2 = 0.18-0.74, p < 0.04), but showed lower inter-agreement. The superior/anterior lung regions showed the least agreement between all three methods (all p > 0.12). CONCLUSION: Absolute VDP assessed by 3D UTE PREFUL MRI showed good global agreement with Xe-MRI and 2D multi-slice PREFUL MRI in pediatric CF lung disease. Therefore, 3D UTE PREFUL MRI offers a sensitive and potentially more accessible alternative to Xe-MRI for regional volumetric evaluation of ventilation.