Efficacy and adverse events profile of videolaryngoscopy in critically ill patients: subanalysis of the INTUBE study.

BACKGROUND: Tracheal intubation is a high-risk procedure in the critically ill, with increased intubation failure rates and a high risk of other adverse events. Videolaryngoscopy might improve intubation outcomes in this population, but evidence remains conflicting, and its impact on adverse event rates is debated. METHODS: This is a subanalysis of a large international prospective cohort of critically ill patients (INTUBE Study) performed from 1 October 2018 to 31 July 2019 and involving 197 sites from 29 countries across five continents. Our primary aim was to determine the first-pass intubation success rates of videolaryngoscopy. Secondary aims were characterising (a) videolaryngoscopy use in the critically ill patient population and (b) the incidence of severe adverse effects compared with direct laryngoscopy. RESULTS: Of 2916 patients, videolaryngoscopy was used in 500 patients (17.2%) and direct laryngoscopy in 2416 (82.8%). First-pass intubation success was higher with videolaryngoscopy compared with direct laryngoscopy (84% vs 79%, P=0.02). Patients undergoing videolaryngoscopy had a higher frequency of difficult airway predictors (60% vs 40%, P<0.001). In adjusted analyses, videolaryngoscopy increased the probability of first-pass intubation success, with an OR of 1.40 (95% confidence interval [CI] 1.05-1.87). Videolaryngoscopy was not significantly associated with risk of major adverse events (odds ratio 1.24, 95% CI 0.95-1.62) or cardiovascular events (odds ratio 0.78, 95% CI 0.60-1.02). CONCLUSIONS: In critically ill patients, videolaryngoscopy was associated with higher first-pass intubation success rates, despite being used in a population at higher risk of difficult airway management. Videolaryngoscopy was not associated with overall risk of major adverse events. CLINICAL TRIAL REGISTRATION: NCT03616054.

Peri-intubation Cardiovascular Collapse in Patients Who Are Critically Ill: Insights from the INTUBE Study.

Rationale: Cardiovascular instability/collapse is a common peri-intubation event in patients who are critically ill. Objectives: To identify potentially modifiable variables associated with peri-intubation cardiovascular instability/collapse (i.e., systolic arterial pressure <65 mm Hg [once] or <90 mm Hg for >30 minutes; new/increased vasopressor requirement; fluid bolus >15 ml/kg, or cardiac arrest). Methods: INTUBE (International Observational Study to Understand the Impact and Best Practices of Airway Management In Critically Ill Patients) was a multicenter prospective cohort study of patients who were critically ill and undergoing tracheal intubation in a convenience sample of 197 sites from 29 countries across five continents from October 1, 2018, to July 31, 2019. Measurements and Main Results: A total of 2,760 patients were included in this analysis. Peri-intubation cardiovascular instability/collapse occurred in 1,199 out of 2,760 patients (43.4%). Variables associated with this event were older age (odds ratio [OR], 1.02; 95% confidence interval [CI], 1.02-1.03), higher heart rate (OR, 1.008; 95% CI, 1.004-1.012), lower systolic blood pressure (OR, 0.98; 95% CI, 0.98-0.99), lower oxygen saturation as measured by pulse oximetry/FiO2 before induction (OR, 0.998; 95% CI, 0.997-0.999), and the use of propofol as an induction agent (OR, 1.28; 95% CI, 1.05-1.57). Patients with peri-intubation cardiovascular instability/collapse were at a higher risk of ICU mortality with an adjusted OR of 2.47 (95% CI, 1.72-3.55), P < 0.001. The inverse probability of treatment weighting method identified the use of propofol as the only factor independently associated with cardiovascular instability/collapse (OR, 1.23; 95% CI, 1.02-1.49). When administered before induction, vasopressors (OR, 1.33; 95% CI, 0.84-2.11) or fluid boluses (OR, 1.17; 95% CI, 0.96-1.44) did not reduce the incidence of cardiovascular instability/collapse. Conclusions: Peri-intubation cardiovascular instability/collapse was associated with an increased risk of both ICU and 28-day mortality. The use of propofol for induction was identified as a modifiable intervention significantly associated with cardiovascular instability/collapse.Clinical trial registered with clinicaltrials.gov (NCT03616054).

Peri-operative management of neuromuscular blockade: A guideline from the European Society of Anaesthesiology and Intensive Care.

Recent data indicated a high incidence of inappropriate management of neuromuscular block, with a high rate of residual paralysis and relaxant-associated postoperative complications. These data are alarming in that the available neuromuscular monitoring, as well as myorelaxants and their antagonists basically allow well tolerated management of neuromuscular blockade. In this first European Society of Anaesthesiology and Intensive Care (ESAIC) guideline on peri-operative management of neuromuscular block, we aim to present aggregated and evidence-based recommendations to assist clinicians provide best medical care and ensure patient safety. We identified three main clinical questions: Are myorelaxants necessary to facilitate tracheal intubation in adults? Does the intensity of neuromuscular blockade influence a patient's outcome in abdominal surgery? What are the strategies for the diagnosis and treatment of residual paralysis? On the basis of this, PICO (patient, intervention, comparator, outcome) questions were derived that guided a structured literature search. A stepwise approach was used to reduce the number of trials of the initial research ( n  = 24 000) to the finally relevant clinical studies ( n  = 88). GRADE methodology (Grading of Recommendations, Assessment, Development and Evaluation) was used for formulating the recommendations based on the findings of the included studies in conjunction with their methodological quality. A two-step Delphi process was used to determine the agreement of the panel members with the recommendations: R1 We recommend using a muscle relaxant to facilitate tracheal intubation (1A). R2 We recommend the use of muscle relaxants to reduce pharyngeal and/or laryngeal injury following endotracheal intubation (1C). R3 We recommend the use of a fast-acting muscle relaxant for rapid sequence induction intubation (RSII) such as succinylcholine 1 mg kg -1 or rocuronium 0.9 to 1.2 mg kg -1 (1B). R4 We recommend deepening neuromuscular blockade if surgical conditions need to be improved (1B). R5 There is insufficient evidence to recommend deep neuromuscular blockade in general to reduce postoperative pain or decrease the incidence of peri-operative complications. (2C). R6 We recommend the use of ulnar nerve stimulation and quantitative neuromuscular monitoring at the adductor pollicis muscle to exclude residual paralysis (1B). R7 We recommend using sugammadex to antagonise deep, moderate and shallow neuromuscular blockade induced by aminosteroidal agents (rocuronium, vecuronium) (1A). R8 We recommend advanced spontaneous recovery (i.e. TOF ratio >0.2) before starting neostigmine-based reversal and to continue quantitative monitoring of neuromuscular blockade until a TOF ratio of more than 0.9 has been attained. (1C).

2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway.

The American Society of Anesthesiologists; All India Difficult Airway Association; European Airway Management Society; European Society of Anaesthesiology and Intensive Care; Italian Society of Anesthesiology, Analgesia, Resuscitation and Intensive Care; Learning, Teaching and Investigation Difficult Airway Group; Society for Airway Management; Society for Ambulatory Anesthesia; Society for Head and Neck Anesthesia; Society for Pediatric Anesthesia; Society of Critical Care Anesthesiologists; and the Trauma Anesthesiology Society present an updated report of the Practice Guidelines for Management of the Difficult Airway.

Tracheostomy outcomes in critically ill patients with COVID-19: a systematic review, meta-analysis, and meta-regression.

BACKGROUND: We performed a systematic review of mechanically ventilated patients with COVID-19, which analysed the effect of tracheostomy timing and technique (surgical vs percutaneous) on mortality. Secondary outcomes included intensive care unit (ICU) and hospital length of stay (LOS), decannulation from tracheostomy, duration of mechanical ventilation, and complications. METHODS: Four databases were screened between January 1, 2020 and January 10, 2022 (PubMed, Embase, Scopus, and Cochrane). Papers were selected according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the Population or Problem, Intervention or exposure, Comparison, and Outcome (PICO) guidelines. Meta-analysis and meta-regression for main outcomes were performed. RESULTS: The search yielded 9024 potentially relevant studies, of which 47 (n=5268 patients) were included. High levels of between-study heterogeneity were observed across study outcomes. The pooled mean tracheostomy timing was 16.5 days (95% confidence interval [CI]: 14.7-18.4; I2=99.6%). Pooled mortality was 22.1% (95% CI: 18.7-25.5; I2=89.0%). Meta-regression did not show significant associations between mortality and tracheostomy timing, mechanical ventilation duration, time to decannulation, and tracheostomy technique. Pooled mean estimates for ICU and hospital LOS were 29.6 (95% CI: 24.0-35.2; I2=98.6%) and 38.8 (95% CI: 32.1-45.6; I2=95.7%) days, both associated with mechanical ventilation duration (coefficient 0.8 [95% CI: 0.2-1.4], P=0.02 and 0.9 [95% CI: 0.4-1.4], P=0.01, respectively) but not tracheostomy timing. Data were insufficient to assess tracheostomy technique on LOS. Duration of mechanical ventilation was 23.4 days (95% CI: 19.2-27.7; I2=99.3%), not associated with tracheostomy timing. Data were insufficient to assess the effect of tracheostomy technique on mechanical ventilation duration. Time to decannulation was 23.8 days (95% CI: 19.7-27.8; I2=98.7%), not influenced by tracheostomy timing or technique. The most common complications were stoma infection, ulcers or necrosis, and bleeding. CONCLUSIONS: In patients with COVID-19 requiring tracheostomy, the timing and technique of tracheostomy did not clearly impact on patient outcomes. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42021272220.

Airway Ultrasound as Predictor of Difficult Direct Laryngoscopy: A Systematic Review and Meta-analysis.

BACKGROUND: Despite several clinical index tests that are currently applied for airway assessment, unpredicted difficult laryngoscopy may still represent a serious problem in anesthesia practice. The aim of this systematic review and meta-analysis was to evaluate whether preoperative airway ultrasound can predict difficult direct laryngoscopy in adult patients undergoing elective surgery under general anesthesia. METHODS: We searched the Medline, Scopus, and Web of Science databases from their inception to December 2020. The population of interest included adults who required tracheal intubation for elective surgery under general anesthesia without clear anatomical abnormalities suggesting difficult laryngoscopy. A bivariate model has been used to assess the accuracy of each ultrasound index test to predict difficult direct laryngoscopy. RESULTS: Fifteen studies have been considered for quantitative analysis of summary receiver operating characteristic (SROC). The sensitivity for distance from skin to epiglottis (DSE), distance from skin to hyoid bone (DSHB), and distance from skin to vocal cords (DSVC) was 0.82 (0.74-0.87), 0.71 (0.58-0.82), and 0.75 (0.62-0.84), respectively. The specificity for DSE, DSHB, and DSVC was 0.79 (0.70-0.87), 0.71 (0.57-0.82), and 0.72 (0.45-0.89), respectively. The area under the curve (AUC) for DSE, DSHB, DSVC, and ratio between the depth of the pre-epiglottic space and the distance from the epiglottis to the vocal cords (Pre-E/E-VC) was 0.87 (0.84-0.90), 0.77 (0.73-0.81), 0.78 (0.74-0.81), and 0.71 (0.67-0.75), respectively. Patients with difficult direct laryngoscopy have higher DSE, DSVC, and DSHB values than patients with easy laryngoscopy, with a mean difference of 0.38 cm (95% confidence interval [CI], 0.17-0.58 cm; P = .0004), 0.18 cm (95% CI, 0.01-0.35 cm; P = .04), and 0.23 cm (95% CI, 0.08-0.39 cm; P = .004), respectively. CONCLUSIONS: Our study demonstrates that airway ultrasound index tests are significantly different between patients with easy versus difficult direct laryngoscopy, and the DSE is the most studied index test in literature to predict difficult direct laryngoscopy. However, it is not currently possible to reach a definitive conclusion. Further studies are needed with better standardization of ultrasound assessment to limit all possible sources of heterogeneity.

Expert consensus statements for the management of COVID-19-related acute respiratory failure using a Delphi method.

BACKGROUND: Coronavirus disease 2019 (COVID-19) pandemic has caused unprecedented pressure on healthcare system globally. Lack of high-quality evidence on the respiratory management of COVID-19-related acute respiratory failure (C-ARF) has resulted in wide variation in clinical practice. METHODS: Using a Delphi process, an international panel of 39 experts developed clinical practice statements on the respiratory management of C-ARF in areas where evidence is absent or limited. Agreement was defined as achieved when > 70% experts voted for a given option on the Likert scale statement or > 80% voted for a particular option in multiple-choice questions. Stability was assessed between the two concluding rounds for each statement, using the non-parametric Chi-square (χ2) test (p < 0·05 was considered as unstable). RESULTS: Agreement was achieved for 27 (73%) management strategies which were then used to develop expert clinical practice statements. Experts agreed that COVID-19-related acute respiratory distress syndrome (ARDS) is clinically similar to other forms of ARDS. The Delphi process yielded strong suggestions for use of systemic corticosteroids for critical COVID-19; awake self-proning to improve oxygenation and high flow nasal oxygen to potentially reduce tracheal intubation; non-invasive ventilation for patients with mixed hypoxemic-hypercapnic respiratory failure; tracheal intubation for poor mentation, hemodynamic instability or severe hypoxemia; closed suction systems; lung protective ventilation; prone ventilation (for 16-24 h per day) to improve oxygenation; neuromuscular blocking agents for patient-ventilator dyssynchrony; avoiding delay in extubation for the risk of reintubation; and similar timing of tracheostomy as in non-COVID-19 patients. There was no agreement on positive end expiratory pressure titration or the choice of personal protective equipment. CONCLUSION: Using a Delphi method, an agreement among experts was reached for 27 statements from which 20 expert clinical practice statements were derived on the respiratory management of C-ARF, addressing important decisions for patient management in areas where evidence is either absent or limited. TRIAL REGISTRATION: The study was registered with Clinical trials.gov Identifier: NCT04534569.

Thoracic Anesthesia during the COVID-19 Pandemic: 2021 Updated Recommendations by the European Association of Cardiothoracic Anaesthesiology and Intensive Care (EACTAIC) Thoracic Subspecialty Committee.

The novel coronavirus pandemic has radically changed the landscape of normal surgical practice. Lifesaving cancer surgery, however, remains a clinical priority, and there is an increasing need to fully define the optimal oncologic management of patients with varying stages of lung cancer, allowing prioritization of which thoracic procedures should be performed in the current era. Healthcare providers and managers should not ignore the risk of a bimodal peak of mortality in patients with lung cancer; an imminent spike due to mortality from acute coronavirus disease 2019 (COVID-19) infection, and a secondary peak reflecting an excess of cancer-related mortality among patients whose treatments were deemed less urgent, delayed, or cancelled. The European Association of Cardiothoracic Anaesthesiology and Intensive Care Thoracic Anesthesia Subspecialty group has considered these challenges and developed an updated set of expert recommendations concerning the infectious period, timing of surgery, vaccination, preoperative screening and evaluation, airway management, and ventilation of thoracic surgical patients during the COVID-19 pandemic.

Intubation Practices and Adverse Peri-intubation Events in Critically Ill Patients From 29 Countries.

Importance: Tracheal intubation is one of the most commonly performed and high-risk interventions in critically ill patients. Limited information is available on adverse peri-intubation events. Objective: To evaluate the incidence and nature of adverse peri-intubation events and to assess current practice of intubation in critically ill patients. Design, Setting, and Participants: The International Observational Study to Understand the Impact and Best Practices of Airway Management in Critically Ill Patients (INTUBE) study was an international, multicenter, prospective cohort study involving consecutive critically ill patients undergoing tracheal intubation in the intensive care units (ICUs), emergency departments, and wards, from October 1, 2018, to July 31, 2019 (August 28, 2019, was the final follow-up) in a convenience sample of 197 sites from 29 countries across 5 continents. Exposures: Tracheal intubation. Main Outcomes and Measures: The primary outcome was the incidence of major adverse peri-intubation events defined as at least 1 of the following events occurring within 30 minutes from the start of the intubation procedure: cardiovascular instability (either: systolic pressure <65 mm Hg at least once, <90 mm Hg for >30 minutes, new or increase need of vasopressors or fluid bolus >15 mL/kg), severe hypoxemia (peripheral oxygen saturation <80%) or cardiac arrest. The secondary outcomes included intensive care unit mortality. Results: Of 3659 patients screened, 2964 (median age, 63 years; interquartile range [IQR], 49-74 years; 62.6% men) from 197 sites across 5 continents were included. The main reason for intubation was respiratory failure in 52.3% of patients, followed by neurological impairment in 30.5%, and cardiovascular instability in 9.4%. Primary outcome data were available for all patients. Among the study patients, 45.2% experienced at least 1 major adverse peri-intubation event. The predominant event was cardiovascular instability, observed in 42.6% of all patients undergoing emergency intubation, followed by severe hypoxemia (9.3%) and cardiac arrest (3.1%). Overall ICU mortality was 32.8%. Conclusions and Relevance: In this observational study of intubation practices in critically ill patients from a convenience sample of 197 sites across 29 countries, major adverse peri-intubation events-in particular cardiovascular instability-were observed frequently.

Aerosol boxes and barrier enclosures for airway management in COVID-19 patients: a scoping review and narrative synthesis.

Exposure of healthcare providers to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a significant safety concern during the coronavirus disease 2019 (COVID-19) pandemic, requiring contact/droplet/airborne precautions. Because of global shortages, limited availability of personal protective equipment (PPE) has motivated the development of barrier-enclosure systems, such as aerosol boxes, plastic drapes, and similar protective systems. We examined the available evidence and scientific publications about barrier-enclosure systems for airway management in suspected/confirmed COVID-19 patients. MEDLINE/Embase/Google Scholar databases (from December 1, 2019 to May 27, 2020) were searched for all articles on barrier enclosures for airway management in COVID-19, including references and websites. All sources were reviewed by a panel of experts using a Delphi method with a modified nominal group technique. Fifty-two articles were reviewed for their results and level of evidence regarding barrier device feasibility, advantages, protection against droplets and aerosols, effectiveness, safety, ergonomics, and cleaning/disposal. The majority of analysed papers were expert opinions, small case series, technical descriptions, small-sample simulation studies, and pre-print proofs. The use of barrier-enclosure devices adds to the complexity of airway procedures with potential adverse consequences, especially during airway emergencies. Concerns include limitations on the ability to perform airway interventions and the aid that can be delivered by an assistant, patient injuries, compromise of PPE integrity, lack of evidence for added protection of healthcare providers (including secondary aerosolisation upon barrier removal), and lack of cleaning standards. Enclosure barriers for airway management are no substitute for adequate PPE, and their use should be avoided until adequate validation studies can be reported.

Thoracic Anesthesia of Patients With Suspected or Confirmed 2019 Novel Coronavirus Infection: Preliminary Recommendations for Airway Management by the European Association of Cardiothoracic Anaesthesiology Thoracic Subspecialty Committee.

The novel coronavirus has caused a pandemic around the world. Management of patients with suspected or confirmed coronavirus infection who have to undergo thoracic surgery will be a challenge for the anesthesiologists. The thoracic subspecialty committee of European Association of Cardiothoracic Anaesthesiology (EACTA) has conducted a survey of opinion in order to create recommendations for the anesthetic approach to these challenging patients. It should be emphasized that both the management of the infected patient with COVID-19 and the self-protection of the anesthesia team constitute a complicated challenge. The text focuses therefore on both important topics.

Noninvasive respiratory support in the hypoxaemic peri-operative/periprocedural patient: A joint ESA/ESICM guideline.

: Hypoxaemia is a potential life-threatening yet common complication in the peri-operative and periprocedural patient (e.g. during an invasive procedure with risk of deterioration of gas exchange, such as bronchoscopy). The European Society of Anaesthesiology (ESA) and the European Society of Intensive Care Medicine (ESICM) have developed guidelines for the use of noninvasive respiratory support techniques in the hypoxaemic patient in the peri-operative and periprocedural period. The panel outlined five clinical questions regarding treatment with noninvasive respiratory support techniques [conventional oxygen therapy (COT), high flow nasal cannula (HFNC), noninvasive positive pressure ventilation (NIPPV) and continuous positive airway pressure (CPAP)] for hypoxaemic patients with acute peri-operative/periprocedural respiratory failure. The goal was to assess the available literature on the various noninvasive respiratory support techniques, specifically studies that included adult participants with hypoxaemia in the peri-operative/periprocedural period. The literature search strategy was developed by a Cochrane Anaesthesia and Intensive Care trial search specialist in close collaboration with the panel members and the ESA group methodologist. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to assess the level of evidence and to grade recommendations. The final process was then validated by both ESA and ESICM scientific committees. Among 19 recommendations, the two grade 1B recommendations state that in the peri-operative/periprocedural hypoxaemic patient, the use of either NIPPV or CPAP (based on local expertise) is preferred to COT for improvement of oxygenation; and that the panel suggests using NIPPV or CPAP immediately postextubation for hypoxaemic patients at risk of developing acute respiratory failure after abdominal surgery.

Awake Fiberoptic Intubation Protocols in the Operating Room for Anticipated Difficult Airway: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

Awake fiberoptic intubation is one of the recommended strategies for surgical patients with anticipated difficult airway, especially when concurrent difficult ventilation is expected. We performed the first systematic review of randomized controlled trials assessing different protocols for awake fiberoptic intubation in anticipated difficult airway, including studies investigating elective awake fiberoptic intubation for scheduled surgery; randomized controlled trials comparing different methods for performing awake fiberoptic intubation; and adult patients with anticipated difficult airway. We excluded studies in the nonoperating theater settings, randomized controlled trials comparing awake fiberoptic intubation with other techniques, and studies based on simulation. Primary outcomes were success rate and death; secondary outcomes were major adverse events. Thirty-seven randomized controlled trials evaluating 2045 patients and 4 areas were identified: premedication, local anesthesia, sedation, and ancillary techniques to facilitate awake fiberoptic intubation. Quality of evidence was moderate-low and based on small-sampled randomized controlled trials. Overall, 12 of 2045 intubation failures (0.59%) and 7 of 2045 severe adverse events (0.34%) occurred, with no permanent consequences or death. All evaluated methods to achieve local anesthesia performed similarly well. No differences were observed in success rate with different sedatives. Dexmedetomidine resulted in fewer desaturation episodes compared to propofol and opioids with or without midazolam (relative risk, 0.51 [95% CI, 0.28-0.95]; P = .03); occurrence of desaturation was similar with remifentanil versus propofol, while incidence of apnoea was lower with sevoflurane versus propofol (relative risk, 0.43 [95% CI, 0.22-0.81]; P = .01). A high degree of efficacy and safety was observed with minimal differences among different protocols; dexmedetomidine might offer a better safety profile compared to other sedatives.

Laryngeal Mask Airway Supreme vs. the Spritztube tracheal cannula in anaesthetised adult patients: A randomised controlled trial.

BACKGROUND: The Spritztube is a new supraglottic airway device combining the ability to allow extraglottic ventilation of the lungs with the opportunity to perform fibreoptic-assisted intubation. OBJECTIVES: To compare the Spritztube tracheal cannula with the Laryngeal Mask Airway Supreme (LMA-S) in anaesthetised adult patients. DESIGN: A single-centre, randomised controlled study. SETTING: Tertiary hospital. PATIENTS: Mechanically ventilated patients undergoing elective surgery in the supine position under general anaesthesia were included. Main exclusion criteria were a history of, or predicted, difficult airway management according to SIAARTI guidelines and absence of written informed consent. INTERVENTIONS: Patients received the LMA-S or Spritztube tracheal cannula to facilitate ventilation of the lungs. MAIN OUTCOME MEASURES: Successful placement (primary outcome), time required for insertion, number of attempts, subjective assessment of ease of insertion, safety and incidence of complications were recorded. RESULTS: One hundred and sixty seven patients were allocated to the LMA-S or Spritztube group, respectively, a total of 334 patients. In the LMA-S group, the device insertion failed in nine patients, compared with none in the Spritztube group (P = 0.002). Spritztube insertion was easy in 100% of cases compared with 94.6% of the cases in the LMA-S group (P = 0.03). The number of attempts was significantly higher with the LMA-S compared with the Spritztube (P = 0.0007), whereas the insertion times were comparable (P = 0.06). Except for the incidence of blood-staining, which was higher in the LMA-S group (P = 0.01), the number of complications was comparable in the two groups. CONCLUSION: The Spritztube was as effective as the LMA-S in maintaining the airway with all patients being successfully ventilated without difficulty. The success rate of achieving a patent airway was comparable between the groups, with a similar occurrence of complications. TRIAL REGISTRATION: NCT03443219.

Evaluation of two neck ultrasound measurements as predictors of difficult direct laryngoscopy: A prospective observational study.

BACKGROUND: Unpredictable difficult laryngoscopy remains a challenge for anaesthesiologists, especially if difficult ventilation occurs during standard laryngoscopy. Accurate airway assessment should always be performed, but the common clinical screening tests have shown low sensitivity and specificity with a limited predictive value. Ultrasound-based airway assessment has been proposed recently as a useful, simple, noninvasive bedside tool as an adjunct to clinical methods, but to date, few studies are available about the potential role of ultrasound in difficult airway evaluation, and these are mostly limited to specific groups of patients. OBJECTIVES: The aim of this study was to determine the correlation between the sonographic measurements of anterior cervical soft tissues thickness and Cormack-Lehane grade view at direct laryngoscopy in patients with normal clinical screening tests. DESIGN: Prospective, single blinded, observational study. SETTING: Operating theatre of a teaching hospital from May 2017 to September 2017. PATIENTS: A total of 301 patients at least 18 years of age undergoing elective surgery under general anaesthesia with tracheal intubation were included in the study. OUTCOME MEASURES: Pre-operative evaluation was performed before surgery, demographic variables were collected and clinical screening tests to predict a difficult airway were performed. Patients with predicted difficult intubation were excluded. A 10 to 13-MHz linear ultrasound transducer was placed in the transverse plane and the thickness of the anterior cervical soft tissues was measured at two levels [thyrohyoid membrane (pre-epiglottic space) and vocal cords (laryngeal inlet)] with the patient's head in a neutral position. At each level, the distance from the skin in the median axis and the surrounding area was measured. The laryngoscopic view was graded by a different anaesthetist with more than 5 years of experience with direct laryngoscopy, blinded to the ultrasound assessments. RESULTS: The 'pre-epiglottic space thickness' at the level of thyrohyoid membrane was measured as the median distance from skin to epiglottis (mDSE) and the pre-epiglottic area was calculated; the mDSE cut-off value of 2.54 cm (sensitivity 82%, specificity 91%) and the pre-epiglottic area cut-off value of 5.04 cm (sensitivity 85%, specificity 88%) were the best predictors of a Cormack-Lehane grade at least 2b at direct laryngoscopy and of difficult intubation. The cut-off value of mDSE showed greater sensitivity in female patients (94 vs. 86%) and greater specificity in male patients (92 vs. 83%). No correlation was found between difficult laryngoscopy and ultrasound assessments at the level of the vocal cords. CONCLUSION: Airways ultrasounds might be considered as a predictor of restricted/difficult laryngoscopy and unpredicted difficult intubation. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03547193.