Hyperangulated vs. Macintosh videolaryngoscopy in adults with anticipated difficult airway management: a randomised controlled trial.

BACKGROUND: It is not certain whether the blade geometry of videolaryngoscopes, either a hyperangulated or Macintosh shape, affects glottic view, success rate and/or tracheal intubation time in patients with expected difficult airways. We hypothesised that using a hyperangulated videolaryngoscope blade would visualise a higher percentage of glottic opening compared with a Macintosh videolaryngoscope blade in patients with expected difficult airways. METHODS: We conducted an open-label, patient-blinded, randomised controlled trial in adult patients scheduled to undergo elective ear, nose and throat or oral and maxillofacial surgery, who were anticipated to have a difficult airway. All airway operators were consultant anaesthetists. Patients were allocated randomly to tracheal intubation with either hyperangulated (C-MAC D-BLADE™) or Macintosh videolaryngoscope blades (C-MAC™). The primary outcome was the percentage of glottic opening. First attempt success was designated a key secondary outcome. RESULTS: We assessed 2540 adults scheduled for elective head and neck surgery for eligibility and included 182 patients with expected difficult airways undergoing orotracheal intubation. The percentage of glottic opening visualised, expressed as median (IQR [range]), was 89 (69-99 [0-100])% with hyperangulated videolaryngoscope blades and 54 (9-90 [0-100])% with Macintosh videolaryngoscope blades (p < 0.001). First-line hyperangulated videolaryngoscopy failed in one patient and Macintosh videolaryngoscopy in 12 patients (13%, p = 0.002). First attempt success rate was 97% with hyperangulated videolaryngoscope blades and 67% with Macintosh videolaryngoscope blades (p < 0.001). CONCLUSIONS: Glottic view and first attempt success rate were superior with hyperangulated videolaryngoscope blades compared with Macintosh videolaryngoscope blades when used by experienced anaesthetists in patients with difficult airways.

Universal paediatric videolaryngoscopy and glottic view grading: a prospective observational study.

BACKGROUND: Although videolaryngoscopy has been proposed as a default technique for tracheal intubation in children, published evidence on universal videolaryngoscopy implementation programmes is scarce. We aimed to determine if universal, first-choice videolaryngoscopy reduces the incidence of restricted glottic views and to determine the diagnostic performance of the Cormack and Lehane classification to discriminate between easy and difficult videolaryngoscopic tracheal intubations in children. METHODS: We conducted a prospective observational study within a structured universal videolaryngoscopy implementation programme. We used C-MAC™ (Karl Storz, Tuttlingen, Germany) videolaryngoscopes in all anaesthetised children undergoing elective tracheal intubation for surgical procedures. The direct and videolaryngoscopic glottic views were classified using a six-stage grading system. RESULTS: There were 904 tracheal intubations in 809 children over a 16-month period. First attempt and overall success occurred in 607 (67%) and 903 (> 99%) tracheal intubations, respectively. Difficult videolaryngoscopic tracheal intubation occurred in 47 (5%) and airway-related adverse events in 42 (5%) tracheal intubations. Direct glottic view during laryngoscopy was restricted in 117 (13%) and the videolaryngoscopic view in 32 (4%) tracheal intubations (p < 0.001). Videolaryngoscopy improved the glottic view in 57/69 (83%) tracheal intubations where the vocal cords were only just visible, and in 44/48 (92%) where the vocal cords were not visible by direct view. The Cormack and Lehane classification discriminated poorly between easy and difficult videolaryngoscopic tracheal intubations with a mean area under the receiver operating characteristic curve of 0.68 (95%CI 0.59-0.78) for the videolaryngoscopic view compared with 0.80 (95%CI 0.73-0.87) for the direct glottic view during laryngoscopy (p = 0.005). CONCLUSIONS: Universal, first-choice videolaryngoscopy reduced substantially the incidence of restricted glottic views. The Cormack and Lehane classification was not a useful tool for grading videolaryngoscopic tracheal intubation in children.

Continuous Finger-cuff versus Intermittent Oscillometric Arterial Pressure Monitoring and Hypotension during Induction of Anesthesia and Noncardiac Surgery: The DETECT Randomized Trial.

BACKGROUND: Finger-cuff methods allow noninvasive continuous arterial pressure monitoring. This study aimed to determine whether continuous finger-cuff arterial pressure monitoring helps clinicians reduce hypotension within 15 min after starting induction of anesthesia and during noncardiac surgery. Specifically, this study tested the hypotheses that continuous finger-cuff-compared to intermittent oscillometric-arterial pressure monitoring helps clinicians reduce the area under a mean arterial pressure of 65 mmHg within 15 min after starting induction of anesthesia and the time-weighted average mean arterial pressure less than 65 mmHg during noncardiac surgery. METHODS: In this single-center trial, 242 noncardiac surgery patients were randomized to unblinded continuous finger-cuff arterial pressure monitoring or to intermittent oscillometric arterial pressure monitoring (with blinded continuous finger-cuff arterial pressure monitoring). The first of two hierarchical primary endpoints was the area under a mean arterial pressure of 65 mmHg within 15 min after starting induction of anesthesia; the second primary endpoint was the time-weighted average mean arterial pressure less than 65 mmHg during surgery. RESULTS: Within 15 min after starting induction of anesthesia, the median (interquartile range) area under a mean arterial pressure of 65 mmHg was 7 (0, 24) mmHg × min in 109 patients assigned to continuous finger-cuff monitoring versus 19 (0.3, 60) mmHg × min in 113 patients assigned to intermittent oscillometric monitoring (P = 0.004; estimated location shift: -6 [95% CI: -15 to -0.3] mmHg × min). During surgery, the median (interquartile range) time-weighted average mean arterial pressure less than 65 mmHg was 0.04 (0, 0.27) mmHg in 112 patients assigned to continuous finger-cuff monitoring and 0.40 (0.03, 1.74) mmHg in 115 patients assigned to intermittent oscillometric monitoring (P < 0.001; estimated location shift: -0.17 [95% CI: -0.41 to -0.05] mmHg). CONCLUSIONS: Continuous finger-cuff arterial pressure monitoring helps clinicians reduce hypotension within 15 min after starting induction of anesthesia and during noncardiac surgery compared to intermittent oscillometric arterial pressure monitoring.

Preoperative Spirometry in Patients With Known or Suspected Chronic Obstructive Pulmonary Disease Undergoing Major Surgery: The Prospective Observational PREDICT Study.

BACKGROUND: Pulmonary function tests (PFTs) such as spirometry and blood gas analysis have been claimed to improve preoperative pulmonary risk assessment, but the scientific literature is conflicting. The Preoperative Diagnostic Tests for Pulmonary Risk Assessment in Chronic Obstructive Pulmonary Disease (PREDICT) study aimed to determine whether preoperative PFTs improve the prediction of postoperative pulmonary complications (PPCs) in patients with known or suspected chronic obstructive pulmonary disease (COPD) undergoing major surgery. A secondary aim was to determine whether the Global Initiative for Chronic Obstructive Lung Diseases (GOLD) classification of airflow limitation severity (grades I-IV) is associated with PPC. METHODS: In this prospective, single-center study, patients with GOLD key indicators for COPD scheduled for major surgery received PFTs. Patients with confirmed COPD (forced expiratory volume in 1 second [FEV1]/forced vital capacity [FVC] ≤0.7) were included in the COPD cohort and compared with a reference cohort without COPD. We developed 3 multivariable risk prediction models and compared their ability to predict PPC: the "standard model" (medical preconditions, and sociodemographic and surgical data), the "COPD assessment model" (additional GOLD key indicators, pack-years, and poor exercise capacity), and the "PFT model" (additional PFT parameters selected by adaptive least absolute shrinkage and selection operator [LASSO] regression). Multiple LASSO regressions were used for cross-validation. RESULTS: A total of 31,714 patients were assessed for eligibility; 1271 individuals received PFTs. Three hundred twenty patients (240 with confirmed COPD: 78 GOLD I, 125 GOLD II, 28 GOLD III, 9 GOLD IV, and 80 without COPD) completed follow-up. The diagnostic performance was similar among the standard model (cross-validated area under the curve [cvAUC], 0.723; bias-corrected bootstrapped [bc-b] 95% confidence interval [CI], 0.663-0.775), COPD assessment model (cvAUC, 0.724; bc-b 95% CI, 0.662-0.777), and PFT model (cvAUC, 0.729; bc-b 95% CI, 0.668-0.782). Previously known COPD was an independent predictor in the standard and COPD assessment model. %FEV1 PRED was the only PFT parameter selected by LASSO regression and was an independent predictor in the PFT model (adjusted odds ratios [OR], 0.98; 95% CI, 0.967-.0.998; P = .030). The risk for PPC significantly increased with GOLD grades ( P < .001). COPD was newly diagnosed in 53.8% of the patients with confirmed COPD; however, these individuals were not at increased risk for PPC ( P = .338). CONCLUSIONS: COPD is underdiagnosed in surgical patients. Patients with newly diagnosed COPD commonly presented with low GOLD severity grades and were not at higher risk for PPC. Neither a structured COPD-specific assessment nor preoperative PFTs added incremental diagnostic value to the standard clinical preassessment in patients with known or suspected COPD. Unnecessary postponement of surgery and undue health care costs can be avoided.

Transnasal Videoendoscopy for Preoperative Airway Risk Stratification: Development and Validation of a Multivariable Risk Prediction Model.

BACKGROUND: Transnasal flexible videoendoscopy (TVE) of the larynx is a standard of care for the detection and staging of pharyngolaryngeal lesions in otorhinolaryngology. Patients frequently present with existing TVE examinations before anesthesia. Although these patients are considered high risk, the diagnostic value of TVE for airway risk stratification is currently unknown. How can captured images or videos be used for anesthesia planning, and which lesions are most concerning? This study aimed to develop and validate a multivariable risk prediction model for difficult airway management based on TVE findings and to determine whether the discrimination of the Mallampati score can be improved by adding this new TVE model. METHODS: This retrospective single-center development and validation study assessed 4021 patients who underwent 4524 otorhinolaryngologic surgeries at the University Medical Centre Hamburg-Eppendorf between January 1, 2011, and April 30, 2018, with electronically stored TVE videos and included 1099 patients who underwent 1231 surgeries. TVE videos and anesthesia charts were systematically reviewed in a blinded fashion. The Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis was used for variable selection, model development, and cross validation. RESULTS: The prevalence of difficult airway management was 24.7% (304/1231). Lesions at the vocal cords, epiglottis, or hypopharynx were not selected by the LASSO regression, while lesions at the vestibular folds (ß-coefficient 0.123), supraglottic region (ß-coefficient 0.161), arytenoids (ß-coefficient 0.063), and viewing restrictions on the rima glottidis that cover ≥50% of the glottis area (ß-coefficient 0.485) and pharyngeal secretion retention (ß-coefficient 0.372) were relevant risk factors for difficult airway management. The model was adjusted for sex, age, and body mass index. The area under the receiver operating characteristic curve (95% confidence interval) of the Mallampati score was 0.61 (0.57-0.65) and 0.74 (0.71-0.78) of the TVE model combined with Mallampati ( P < .001). CONCLUSIONS: Stored images and videos from TVE examinations can be reused for the purpose of predicting risk associated with airway management. Vestibular fold, supraglottic, and arytenoid lesions are most concerning, especially if they are accompanied by secretion retention or restrict the glottic view. Our data indicate that the TVE model improves discrimination of the Mallampati score and might, therefore, be a useful addition to traditional bedside airway risk examinations.

Vie Scope® versus videolaryngoscopy in expected difficult airways: a randomized controlled trial.

PURPOSE: The management of patients with an anticipated difficult airway remains challenging. We evaluated laryngeal visualization with the recently introduced Vie Scope® as a straight blade laryngoscope consisting of an illuminated tube necessitating bougie-facilitated intubation vs Macintosh videolaryngoscopy. METHODS: We conducted a prospective randomized controlled noninferiority trial. Patients undergoing elective ear, nose, and throat or oral and maxillofacial surgery with an anticipated difficult airway were randomized 1:1 to receive tracheal intubation with the Vie Scope or Macintosh videolaryngoscope (C-MAC®). The primary outcome measure was laryngeal visualization by the percentage of glottis opening (POGO) scale. Secondary outcome measures were the time to successful intubation (TTI) and first-attempt and overall success rates. RESULTS: We included two sets of 29 patients in our analysis. For visualization, the Vie Scope was noninferior to videolaryngoscopy (VL) with mean (standard deviation [SD]) POGO scores of 71 (31)% vs 64 (30)% in the VL group [difference in means, 7 (8)%; 95% confidence interval, -9 to 23; P = 0.38]. Mean (SD) TTI was 125 (129) sec in the Vie Scope and 51 (36) sec in the VL group (difference in means, 75 sec; 95% confidence interval, 25 to 124; P = 0.005). The first-attempt and overall success rates were 22/29 (76%) and 27/29 (93%) in both groups. Two patients per group were switched to a different device. Four accidental esophageal intubations occurred in the Vie Scope group, these were presumably due to bougie misplacement. CONCLUSION: Visualization with the Vie Scope was noninferior to VL in patients with an anticipated difficult airway, but TTI was longer in the Vie Scope group. STUDY REGISTRATION: ClinicalTrials.gov (NCT05044416); registered 5 September 2021.

RéSUMé: OBJECTIF: La prise en charge des patients dont les voies aériennes sont anticipées comme étant difficiles demeure un défi. Nous avons évalué la visualisation laryngée obtenue avec le nouveau Vie Scope®, un laryngoscope à lame droite constitué d'un tube éclairé nécessitant une intubation facilitée par bougie, par rapport à celle obtenue avec un vidéolaryngoscope Macintosh. MéTHODE: Nous avons réalisé une étude randomisée contrôlée prospective de non-infériorité. Les patient·es bénéficiant d'une chirurgie non urgente des oreilles, du nez et de la gorge ou une chirurgie buccale et maxillo-faciale présentant des voies aériennes anticipées comme difficiles ont été randomisé·es à un ratio 1:1 à recevoir une intubation trachéale avec un laryngoscope Vie Scope ou un vidéolaryngoscope Macintosh (C-MAC®). Le critère d'évaluation principal était la visualisation laryngée selon l'échelle de pourcentage d'ouverture de la glotte (POGO). Les critères d'évaluation secondaires étaient le délai avant une intubation réussie et les taux de réussite de la première tentative et globaux. RéSULTATS: Nous avons inclus deux groupes de 29 patient·es dans notre analyse. En matière de visualisation, le Vie Scope n'était pas inférieur à la vidéolaryngoscopie (VL), avec des scores POGO moyens (écart type [ET]) de 71 (31) % vs 64 (30) % dans le groupe VL [différence dans les moyennes, 7 (8) %; intervalle de confiance à 95 %, ­9 à 23; P = 0,38]. Le délai moyen (ET) avant une intubation réussie était de 125 (129) sec avec le Vie Scope et de 51 (36) secondes dans le groupe VL (différence dans les moyennes, 75 sec; intervalle de confiance à 95 %, 25 à 124; P = 0,005). Les taux de réussite de la première tentative et de réussite globale étaient de 22/29 (76 %) et 27/29 (93 %) dans les deux groupes. Un dispositif différent a dû être utilisé chez deux patient·es par groupe. Quatre intubations œsophagiennes accidentelles sont survenues dans le groupe Vie Scope; celles-ci étaient probablement dues à un mauvais placement de la bougie. CONCLUSION: La visualisation obtenue avec le Vie Scope n'était pas inférieure à la vidéolaryngoscopie chez les patient·es dont les voies aériennes étaient anticipées comme difficiles, mais le délai avant une intubation réussie était plus long dans le groupe Vie Scope. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT05044416); registered 5 September 2021.

Cardiovascular dynamics during peroral endoscopic myotomy for esophageal achalasia: a prospective observational study using non-invasive finger cuff-derived pulse wave analysis.

Peroral endoscopic myotomy (POEM) is natural orifice transluminal endoscopic surgery to treat esophageal achalasia. During POEM, cardiovascular dynamics can be impaired by capnoperitoneum, capnomediastinum, and systemic carbon dioxide accumulation. We systematically investigated changes in cardiovascular dynamics during POEM. We included 31 patients having POEM in this single-center prospective observational study. Before and every 5 min during POEM we measured mean arterial pressure (MAP), heart rate (HR), cardiac index (CI), stroke volume index (SVI), and systemic vascular resistance index (SVRI) using non-invasive finger cuff-derived pulse wave analysis. During POEM, the median MAP was higher than the median baseline MAP of 77 (67;86) mmHg. HR (median at baseline: 67 (60;72) bpm), CI (2.8 (2.5;3.2) L/min/m2), SVI (42 (34;51) mL/m2), and SVRI (1994 (1652; 2559) dyn × s × cm-5 × m-2) remained stable during POEM. Mixed model-derived 95% confidence limits of hemodynamic variables during POEM were 72 to 106 mmHg for MAP, 65 to 79 bpm for HR, 2.7 to 3.3 L/min/m2 for CI, 37 and 46 mL/m2 for SVI, and 1856 and 2954 dyn × s × cm-5 × m-2 for SVRI. POEM is a safe procedure with regard to cardiovascular dynamics as it does not markedly impair MAP, HR, CI, SVI, or SVRI.

Anesthesia for Patients Undergoing Peroral Endoscopic Myotomy Procedures: A Review of the Literature.

Idiopathic achalasia is a motility disorder of the esophagus with important implications on anesthesia and periprocedural management. As new and more complex treatment options develop, anesthesiologists are increasingly involved with these patients. The cardinal symptoms of achalasia are as follows: dysphagia, regurgitation, chest pain, and weight loss. Achalasia is also associated with an increased risk of aspiration. Patients are frequently treated by endoscopic botulinum toxin injections, pneumatic dilation of the lower esophageal sphincter, laparoscopic Heller myotomy, or peroral endoscopic myotomy (POEM). The POEM procedure is based on the concept of "natural orifice transluminal endoscopic surgery." Because the integrity of the esophageal wall is deliberately interrupted during POEM, the mediastinum and the peritoneal cavity may be exposed. Thus, the insufflated carbon dioxide frequently causes hypercapnia, tension capnoperitoneum, capnomediastinum, or pneumothoraces. An interdisciplinary team, skilled in diagnostics and emergency measures such as therapeutic hyperventilation, percutaneous abdominal needle decompression, or pleural drainage, is essential for the successful periprocedural management of POEM. POEM is one endoscopic procedure that requires general anesthesia. But neither anesthesia-specific care algorithms nor evidence-based recommendations are currently available for these patients. Because institutional experience varies broadly across the globe, this review examines anesthesia recommendations and perioperative management of POEM procedures based on 7 retrospective case series, 1 prospective study, and our personal experience.

Airway management and perioperative adverse events in children with mucopolysaccharidoses and mucolipidoses: A retrospective cohort study.

BACKGROUND: Children suffering from mucopolysaccharidoses (subtypes I, II, III, IV, VI, and VII) or mucolipidoses often require anesthesia, but are at high risk for perioperative adverse events. However, the impact of the disease subtype and the standard of care for airway management are still unclear. AIMS: This study aimed to assess independent risk factors for perioperative adverse events in individuals with mucopolysaccharidoses/mucolipidoses and to analyze the interaction with the primary airway technique implemented. METHODS: This retrospective study included individuals with mucopolysaccharidoses/mucolipidoses who underwent anesthesia at two high-volume centers from 2002 to 2016. The data were analyzed in a multivariate hierarchical model, accounting for repeated anesthesia procedures within the same patient and for multiple events within a single anesthesia. RESULTS: Of 141 identified inpatients, 67 (63 mucopolysaccharidoses and 4 mucolipidoses) underwent 269 anesthesia procedures (study cases) for 353 surgical or diagnostic interventions. At least one perioperative adverse event occurred in 25.6% of the cases. The risk for perioperative adverse events was higher in mucopolysaccharidoses type I (OR 8.0 [1.5-42.7]; P = .014) or type II (OR 8.8 [1.3-58.6]; P = .025) than in type III. Fiberoptic intubation through a supraglottic airway was associated with the lowest risk for perioperative adverse events and lowest conversion rate. Direct laryngoscopy was associated with a significantly higher risk for airway management problems than indirect techniques (estimated event rates 47.8% vs 10.1%, OR 24.05 [5.20-111.24]; P < .001). The risk for respiratory adverse events was significantly higher for supraglottic airway (22.6%; OR 31.53 [2.79-355.88]; P = .001) and direct laryngoscopy (14.8%; OR 14.70 [1.32-163.44]; P = .029) than for fiberoptic intubation through a supraglottic airway (2.1%). CONCLUSIONS: The disease subtype and primary airway technique were the most important independent risk factors for perioperative adverse events. Our findings indicate that in MPS/ML children with predicted difficult airway indirect techniques should be favored for the first tracheal intubation attempt.

Continuous noninvasive arterial blood pressure monitoring using the vascular unloading technology during complex gastrointestinal endoscopy: a prospective observational study.

The innovative vascular unloading technology (VUT) allows continuous noninvasive arterial blood pressure (AP) monitoring. We aimed to investigate whether the VUT enables AP changes to be detected earlier compared with intermittent AP monitoring in patients undergoing gastrointestinal endoscopy. In this prospective observational study, we recorded continuous AP measurements with the VUT (CNAP system; CNSystems Medizintechnik AG, Graz, Austria) and intermittent AP measurements with upper arm cuff oscillometry in 90 patients undergoing complex gastrointestinal endoscopy (Department of Interventional Endoscopy at the University Medical Center Hamburg-Eppendorf, Hamburg, Germany). A "hypotensive phase" was defined as a time period of at least 30 s during which ≥ 50% of the VUT-AP values were in a predefined range of hypotension, i.e., AP value a) ≥ 10% below the last oscillometric value and b) ≤ 65 mmHg for mean AP or ≤ 90 mmHg for systolic AP. In the 5-min-interval between two oscillometric measurements, one or more hypotensive phases were detected in 26 patients (29%) for mean AP and in 27 patients (30%) for systolic AP. Hypotensive phases had a mean duration of 195 ± 99 s for mean AP and 197 ± 97 s for systolic AP with a mean procedure duration of 36 (± 21) min. Continuous noninvasive AP monitoring using the VUT enables hypotensive phases to be detected earlier compared with intermittent AP monitoring during complex gastrointestinal endoscopy. These hypotensive phases may be missed or only belatedly recognized with intermittent AP monitoring. Continuous noninvasive AP measurement facilitates detecting hemodynamic instability more rapidly and therefore may improve patient safety.

Early adverse events of per-oral endoscopic myotomy.

BACKGROUND AND AIMS: The recently developed technique of per-oral endoscopic myotomy (POEM) has been shown to be effective for the therapy of esophageal motility disorders. Limited information is available about POEM adverse events (AEs). METHODS: POEM was performed on 241 patients (58% male; mean age, 47.4 ± 16.4 years) under general anesthesia over 61 months. The main outcome was the rate of intra- and post-procedural AEs. Post-procedural checks comprised clinical and laboratory examinations and endoscopy, with further follow-ups performed at 3, 6, and 12 months. RESULTS: Of the 241 procedures, 238 were successfully completed (mean procedure time, 100.2 ± 39.5 min). Reasons for abortion were excessive submucosal fibrosis preventing submucosal tunneling. Three patients had severe procedural-related AEs (SAE rate, 1.2%); 1 case of pneumothorax required intra-procedural drainage, and 2 patients had delayed SAEs (1 ischemic gastric cardia perforation and 1 hemothorax, both leading to surgery). The overall rate of minor AEs was 31.1%, mainly prolonged intra-procedural bleeding (>15 min hemostasis) and defects of the mucosa overlying the tunnel; none led to clinically relevant signs or symptoms. Patients experiencing any AE had a significantly prolonged hospital stay (P = .037) and a trend toward prolonged procedure time (P = .094). Neck/upper thoracic emphysema and free abdominal air were noted in 31.5% and 35.7%, respectively (95.3% drained), but without relevant sequelae. CONCLUSIONS: POEM has a low rate of SAEs; minor AEs are more frequent but lack a consistent definition. Therefore, based on our experience and literature analysis, we suggest a classification of AEs for POEM. (Clinical trials registration number: NCT01405417.).

Anesthetic considerations for patients with esophageal achalasia undergoing peroral endoscopic myotomy: a retrospective case series review.

PURPOSE: Peroral endoscopic myotomy (POEM) is a novel technique for treating esophageal achalasia. During POEM, carbon dioxide (CO2) is insufflated to aid surgical dissection, but it may inadvertently track into surrounding tissues, causing systemic CO2 uptake and tension capnoperitoneum. This in turn may affect cardiorespiratory function. This study quantified these cardiorespiratory effects and treatment by hyperventilation and percutaneous abdominal needle decompression (PND). METHODS: One hundred and seventy-three consecutive patients who underwent POEM were included in this four-year retrospective study. Procedure-related changes in peak inspiratory pressure (pmax), end-tidal CO2 levels (etCO2), minute ventilation (MV), mean arterial pressure (MAP), and heart rate (HR) were analyzed. We also quantified the impact of PND on these cardiorespiratory parameters. RESULTS: During the endoscopic procedure, cardiorespiratory parameters increased from baseline: pmax 15.1 (4.5) vs 19.8 (4.7) cm H2O; etCO2 4.5 (0.4) vs 5.5 (0.9) kPa [34.0 (2.9) vs 41.6 (6.9) mmHg]; MAP 73.9 (9.7) vs 99.3 (15.2) mmHg; HR 67.6 (12.4) vs 85.3 (16.4) min-1 (P < 0.001 for each). Hyperventilation [MV 5.9 (1.2) vs 9.0 (1.8) L·min-1, P < 0.001] was applied to counteract iatrogenic hypercapnia. Individuals with tension capnoperitoneum treated with PND (n = 55) had higher peak pmax values [22.8 (5.7) vs 18.4 (3.3) cm H2O, P < 0.001] than patients who did not require PND. After PND, pmax [22.8 (5.7) vs 19.9 (4.3) cm H2O, P = 0.045] and MAP [98.2 (16.3) vs 88.6 (11.8) mmHg, P = 0.013] decreased. Adverse events included pneumothorax (n = 1), transient myocardial ischemia (n = 1), and subcutaneous emphysema (n = 49). The latter precluded immediate extubation in eight cases. Postanesthesia care unit (PACU) stay was longer in individuals with subcutaneous emphysema than in those without [74.9 min (34.5) vs 61.5 (26.8 min), P = 0.007]. CONCLUSION: Carbon dioxide insufflation during POEM produces systemic CO2 uptake and increased intra-abdominal pressure. Changes in cardiorespiratory parameters include increased pmax, etCO2, MAP, and HR. Hyperventilation and PND help mitigate some of these changes. Subcutaneous emphysema is common and may delay extubation and prolong PACU stay.

Cell Fixation by Light-Triggered Release of Glutaraldehyde.

Chemical fixation of living cells for microscopy is commonly achieved by crosslinking of intracellular proteins with dialdehydes prior to examination. We herein report a photocleavable protecting group for glutaraldehyde that results in a light-triggered and membrane-permeable fixative, which is nontoxic prior to photocleavage. Lipophilic ester groups allow for diffusion across the cell membrane and intracellular accumulation after enzymatic hydrolysis. Irradiation with UV light releases glutaraldehyde. The in situ generated fixative crosslinks intracellular proteins and preserves and stabilizes the cell so that it is ready for microscopy. In contrast to conventional glutaraldehyde fixation, tissue autofluorescence does not increase after fixation. Caged glutaraldehyde may in future enable functional experiments on living cells under a light microscope in which events of interest can be stopped in spatially confined volumes at defined time points. Samples with individually stopped events could then later be analyzed in ultrastructural studies.

A biphasic mercury-ion sensor: exploiting microfluidics to make simple anilines competitive ligands.

Combining the molecular wire effect with a biphasic sensing approach (analyte in water, sensor-dye in 2-methyltetrahydrofuran) and a microfluidic flow setup leads to the construction of a mercury-sensitive module. We so instantaneously detect Hg(2+) ions in water at a 500 µM concentration. The sensor, conjugated non-water soluble polymer 1 (XFPF), merely supports dibutylaniline substituents as binding units. Yet, selective and sensitive detection of Hg(2+) -ions is achieved in water. The enhancement in sensory response, when comparing the reference compound 2 to that of 1 in a biphasic system in a microfluidic chip is >10(3) . By manipulation of the structure of 1, further powerful sensor systems should be easily achieved.

Emission turn-on and solubility turn-off in conjugated polymers: one- and two-photon-induced removal of fluorescence-quenching solubilizing groups.

The synthesis of highly efficient two-photon uncaging groups and their potential use in functional conjugated polymers for post-polymerization modification are reported. Careful structural design of the employed nitrophenethyl caging groups allows to efficiently induce bond scission by a two-photon process through a combination of exceptionally high two-photon absorption cross-sections and high reaction quantum yields. Furthermore, π-conjugated polyfluorenes are functionalized with these photocleavable side groups and it is possible to alter their emission properties and solubility behavior by simple light irradiation. Cleavage of side groups leads to a turn-on of the fluorescence while solubility of the π-conjugated materials is drastically reduced.

Dynamic device properties of pulse contour cardiac output during transcatheter aortic valve implantation.

This prospective single-center study aimed to determine the responsiveness and diagnostic performance of continuous cardiac output (CCO) monitors based on pulse contour analysis compared with invasive mean arterial pressure (MAP) during predefined periods of acute circulatory deterioration in patients undergoing transcatheter aortic valve implantation (TAVI). The ability of calibrated (CCO(CAL)) and self-calibrated (CCO(AUTOCAL)) pulse contour analysis to detect the hemodynamic response to 37 episodes of balloon aortic valvuloplasty enabled by rapid ventricular pacing was quantified in 13 patients undergoing TAVI. A "low" and a "high" cut-off limit were predefined as a 15 or 25 % decrease from baseline respectively. We found no significant differences between CCO(CAL) and MAP regarding mean response time [low cut-off: 8.6 (7.1-10.5) vs. 8.9 (7.3-10.8) s, p = 0.76; high cut-off: 11.4 (9.7-13.5) vs. 12.6 (10.7-14.9) s, p = 0.32] or diagnostic performance [area under the receiver operating characteristics curve (AUC): 0.99 (0.98-1.0) vs. 1.0 (0.99-1.0), p = 0.46]. But CCOCAL had a significantly higher amplitude response [95.0 (88.7-98.8) % decrease from baseline] than MAP [41.2 (30.0-52.9) %, p < 0.001]. CCOAUTOCAL had a significantly lower AUC [0.83 (0.73-0.93), p < 0.001] than MAP. Moreover, CCO(CAL) detected hemodynamic recovery significantly earlier than MAP. In conclusion, CCO(CAL) and MAP provided equivalent responsiveness and diagnostic performance to detect acute circulatory depression, whereas CCO(AUTOCAL) appeared to be less appropriate. In contrast to CCO(CAL) the amplitude response of MAP was poor. Consequently even small response amplitudes of MAP could indicate severe decreases in CO.

Cardiac index assessment using bioreactance in patients undergoing cytoreductive surgery in ovarian carcinoma.

This clinical study compared the cardiac index (CI) assessed by the totally non-invasive method of bioreactance (CIBR) (NICOM™, Cheetah Medical, Vancouver, USA) to transpulmonary thermodilution (CITD) during cytoreductive surgery in ovarian carcinoma. The hypothesis was that CI could be assessed by bioreactance in an accurate and precise manner including accurate trending ability when compared to transpulmonary thermodilution. In 15 patients CIBR and CITD were assessed after induction of anesthesia, after opening of the peritoneum, hourly during the operative procedure, and 30 min after extubation. Trending ability was assessed between the described timepoints. In total 84 points of measurement were analyzed. Concordance correlation coefficient for repeated measures correlating the CIBR and CITD was 0.32. Bias was 0.26 l/min/m(2) (limits of agreement -1.39 and 1.92 l/min/m(2)). The percentage error was 50.7 %. Trending ability quantified by the mean of angles θ which are made by the ΔCI vector and the line of identity (y = x) showed a value for CIBR of θ = 23.4°. CI assessment by bioreactance showed acceptable accuracy and trending ability. However, its precision was poor. Therefore, CI measurement can not be solely based on bioreactance in patients undergoing cytoreductive surgery in ovarian carcinoma.

Comparison of nasotracheal versus orotracheal intubation for sedation, assisted spontaneous breathing, mobilization, and outcome in critically ill patients: an exploratory retrospective analysis.

Nasotracheal intubation (NTI) may be used for long term ventilation in critically ill patients. Although tracheostomy is often favored, NTI may exhibit potential benefits. Compared to orotracheal intubation (OTI), patients receiving NTI may require less sedation and thus be more alert and with less episodes of depression of respiratory drive. We aimed to study the association of NTI versus OTI with sedation, assisted breathing, mobilization, and outcome in an exploratory analysis. Retrospective data on patients intubated in the intensive care unit (ICU) and ventilated for > 48 h were retrieved from electronic records for up to ten days after intubation. Outcome measures were a Richmond Agitation and Sedation Scale (RASS) of 0 or - 1, sedatives, vasopressors, assisted breathing, mobilization on the ICU mobility scale (ICU-MS), and outcome. From January 2018 to December 2020, 988 patients received OTI and 221 NTI. On day 1-3, a RASS of 0 or - 1 was attained in OTI for 4.0 ± 6.1 h/d versus 9.4 ± 8.4 h/d in NTI, p < 0.001. Propofol, sufentanil, and norepinephrine were required less frequently in NTI and doses were lower. The NTI group showed a higher proportion of spontaneous breathing from day 1 to 7 (day 1-6: p < 0.001, day 7: p = 0.002). ICU-MS scores were higher in the NTI group (d1-d9: p < 0.001, d10: p = 0.012). OTI was an independent predictor for mortality (odds ratio 1.602, 95% confidence interval 1.132-2.268, p = 0.008). No difference in the rate of tracheostomy was found. NTI was associated with less sedation, more spontaneous breathing, and a higher degree of mobilization during physiotherapy. OTI was identified as an independent predictor for mortality. Due to these findings a new prospective evaluation of NTI versus OTI should be conducted to study risks and benefits in current critical care medicine.