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Objectives: Microaspiration of subglottic secretions plays a pivotal role in ventilator-associated pneumonia. Impact of endotracheal tube cuff material and shape on tracheal sealing performance remains debated. The primary objective was to compare the tracheal sealing performance of polyvinyl chloride tapered, cylindrical and spherical cuffs. Secondary objectives were to determine the impact of continuous cuff pressure control on sealing performance and pressure variability., Design: Prospective randomized ex vivo animal study., Setting: French research laboratory., Subjects: Seventy-two ex vivo pig tracheal two-lung blocks., Interventions: Blocks were randomly intubated with cylindrical (n = 26), tapered (n = 24), or spherical (n = 22) polyvinyl chloride endotracheal tube cuffs. Two milliliter of methylene blue were instilled above the cuff to quantify microaspirations, and lungs were ventilated for 2 hours. Continuous cuff pressure control was implemented in 33 blocks., Measurements and Main Results: Cuff pressures were continuously recorded, and after 2 hours, a microaspiration score was calculated. Tapered cuffs improved cuff sealing performance compared with spherical cuffs with or without continuous cuff pressure control. Compared with spherical cuffs, tapered cuffs reduced the microaspiration score without and with continuous pressure control by 65% and 72%, respectively. Continuous cuff pressure control did not impact sealing performance. Tapered cuffs generated higher cuff pressures and increased the time spent with overinflation compared with spherical cuffs (median [interquartile range], 77.9% [0-99.8] vs. 0% [0-0.5]; p = 0.03). Continuous cuff pressure control reduced the variability of tapered and spherical cuffs likewise the time spent with overinflation of tapered and cylindrical cuffs., Conclusions: Polyvinyl chloride tapered cuffs sealing enhanced performance at the cost of an increase in cuff pressure and in time spent with overinflation. Continuous cuff pressure control reduced the variability and normalized cuff pressures without impacting sealing performance.

Background: Patients undergoing major vascular surgery often develop postoperative pneumonia that impacts their outcomes. Conflicting data exist concerning the potential benefit of tapered-shaped cuffs on tracheal sealing. The primary objective of this study was to assess the efficiency of a polyvinyl chloride tapered-cuff endotracheal tube at reducing the postoperative pneumonia rate after major vascular surgery. Secondary objectives were to determine its impact on microaspiration, ventilator-associated pneumonia rate, and inner cuff pressure., Methods: This prospective randomized controlled study included 109 patients who were randomly assigned to receive either spherical- (standard cuff) or taper-shaped (tapered cuff) endotracheal tubes inserted after anesthesia induction and then admitted to the intensive care unit after major vascular surgery. Cuff pressure was continuously recorded over 5 h. Pepsin and α-amylase concentrations in tracheal aspirates were quantified on postoperative days 1 and 2. The primary outcome was the early postoperative pneumonia frequency., Results: Comparing the tapered-cuff with standard-cuff group, respectively, postoperative pneumonia rates were comparable (42 vs. 44%, P = 0.87) and the percentage (interquartile range) of cuff-pressure time with overinflation was significantly higher (16.1% [1.5 to 50] vs. 0.6% [0 to 8.3], P = 0.01), with a 2.5-fold higher coefficient of variation (20.2 [10.6 to 29.4] vs. 7.6 [6.2 to 10.2], P < 0.001). Although microaspiration frequencies were high, they did not differ between groups., Conclusion: For major vascular surgery patients, polyvinyl chloride tapered-cuff endotracheal tubes with intermittent cuff-pressure control did not lower the early postoperative pneumonia frequency and did not prevent microaspiration.

Background: It has been suggested that predicting difficult tracheal intubation is useless because of the poor predictive capacity of individual signs and scores. The authors tested the hypothesis that an accurate prediction of difficult tracheal intubation using simple clinical signs is possible using a computer-assist model., Methods: In a cohort of 1,655 patients, the authors analyzed the predictive properties of each of the main signs (Mallampati score, mouth opening, thyromental distance, and body mass index) to predict difficult tracheal intubation. They built the best score possible using a simple logistic model (SCOREClinic) and compared it with the more recently described score in the literature (SCORENaguib). Then they used a boosted tree analysis to build the best score possible using computer-assisted calculation (SCOREComputer)., Results: Difficult tracheal intubation occurred in 101 patients (6.1%). The predictive properties of each sign remain low (maximum area under the receiver operating characteristic curve 0.70). Using receiver operating characteristic curve, the global prediction of the SCOREClinic (0.74, 95% CI: 0.72-0.76) was greater than that of the SCORENaguib (0.66, 95% CI: 0.60-0.72, P<0.001) but significantly lower than that of the SCOREComputer (0.86, 95% CI: 0.84-0.91, P<0.001). The proportion of patients in the inconclusive zone was 71% using SCORENaguib, 56% using SCOREClinic, and only 32 % using SCOREComputer (all P<0.001)., Conclusion: Computer-assisted models using complex interaction between variables enable an accurate prediction of difficult tracheal intubation with a low proportion of patients in the inconclusive zone. An external validation of the model is now required.

Background: Single-use metal laryngoscope blades are cheaper and carry a lower risk of infection than reusable metal blades. The authors compared single-use and reusable metal blades during rapid sequence induction of anesthesia in a multicenter cluster randomized trial., Methods: One thousand seventy-two adult patients undergoing general anesthesia under emergency conditions and requiring rapid sequence induction were randomly assigned on a weekly basis to either single-use or reusable metal blades (cluster randomization). After induction, a 60-s period was allowed to complete intubation. In the case of failed intubation, a second attempt was performed using the opposite type of blade. The primary endpoint was the rate of failed intubation, and the secondary endpoints were the incidence of complications (oxygen desaturation, lung aspiration, and/or oropharynx trauma) and the Cormack and Lehane score., Results: Both groups were similar in their main characteristics, including the risk factors for difficult intubation. The rate of failed intubation was significantly decreased with single-use metal blades at the first attempt compared with reusable blades (2.8 vs. 5.4%, P < 0.05). In addition, the proportion of grades III and IV in Cormack and Lehane score were also significantly decreased with single-use metal blades (6 vs. 10%, P < 0.05). The global complication rate did not reach statistical significance, although the same trend was noted (6.8% vs. 11.5%, P = not significant). An investigator survey and a measure of illumination pointed that illumination might have been responsible for this result., Conclusions: The single-use metal blade was more efficient than a reusable metal blade in rapid sequence induction of anesthesia.

Background and Objective: Using the Intubation Difficulty Scale (IDS) more than 5 as a standardized definition of difficult intubation, we propose a new score to predict difficult intubation: the Simplified Predictive Intubation Difficulty Score (SPIDS)., Methods: We prospectively studied 1024 patients scheduled for elective surgery under general anaesthesia. Using bivariate and multivariable analysis, we established risk factors of difficult intubation. Then, we assigned point values to each of the adjusted risk factors, their sum composing the SPIDS. We assessed its predictive accuracy using sensitivity, specificity, positive (PPV) and negative predictive values (NPV), and the area under the receiver operating characteristic (ROC) curve (AUC), and compared it with the corresponding nonweighted score. The optimal predictive level of the SPIDS was determined using ROC curve analysis., Results: We found five adjusted risk factors for IDS more than 5: pathological conditions associated with difficult intubation (malformation of the face, acromegaly, cervical rheumatism, tumours of the airway, and diabetes mellitus), mouth opening less than 3.5 cm, a ratio of patient's height to thyromental distance 25 at least, head and neck movement less than 80 degrees , and Mallampati 2 at least. Sensitivity, specificity, PPV and NPV of the SPIDS were 65, 76, 14 and 97%, respectively. AUC of the SPIDS and the nonweighted score (obtained previously using a stepwise logistic regression) were respectively 0.78 [95% confidence interval (CI) 0.72-0.84] and 0.69 (95% CI 0.64-0.73). The threshold for an optimal predictive level of the SPIDS was above 10 of 55., Conclusion: The SPIDS seems easy to perform, and by weighting risk factors of difficult intubation, it could help anaesthesiologists to plan a difficult airway management strategy. A value of SPIDS strictly above 10 could encourage the anaesthesiologists to plan for the beginning of the anaesthetic induction with 'alternative' airway devices ready in the operating theatre.

Background: Lightwand tracheal intubation is a suitable technique for patients who are difficult to intubate but who are receiving effective ventilation. The effect of muscle relaxants on the efficacy of lightwand intubation has not yet been evaluated. The authors conducted a prospective, double-blind, placebo-controlled study to assess the effectiveness and incidence of complications of lightwand tracheal intubation performed during general anesthesia with and without the use of a muscle relaxant in patients with apparently normal airway anatomy., Methods: One hundred seventy-six patients who required orotracheal intubation were prospectively included. Anesthesia was administered using propofol (2 mg/kg, then 3 mg . kg (-1). h(-1)) and remifentanil (1 microg/kg, then 0.3 microg . kg(-1) . min(-1)). Patients were randomly assigned to one of two groups (n = 88 for each) to receive rocuronium 0.6 mg/kg or saline intravenously. Lightwand orotracheal intubation (Trachlight; Laerdal Medical Inc., Armonk, NY) was attempted after 3 min. The authors recorded the number of successful intubations, the number of attempts and their duration, and events during the procedure., Results: The failure rate of lightwand intubation was 12% in the placebo group and 2% in the rocuronium group (P = 0.021). Patients in the placebo group received more multiple intubation attempts (P < 0.001), required a greater intubation time (77 +/- 65 vs. 52 +/- 31 s; P = 0.002) and experienced a greater incidence of events during intubation (61 vs. 0%; P < 0.001) than patients in the rocuronium group., Conclusions: The use of muscle relaxants in patients with apparently normal airways is associated with a lower failure rate, decreased intubation time, and fewer attempts when performing lightwand orotracheal intubation.

Difficulties or failure in airway management are still important factors in morbidity and mortality related to anesthesia and intensive care. A patent and secure airway is essential to manage anesthetized or critically ill patients. Oxygenation maintenance during tracheal intubation is the cornerstone of difficult airway management and is always emphasized in guidelines. The occurrence of respiratory adverse events has decreased in claims for injuries due to inadequate airway management mainly at induction of anesthesia. Nevertheless, claim reports emphasize that airway emergencies, tracheal extubation and/or recovery of anesthesia phases are still associated with death or brain damage, indicating that additional educational support and management strategies to improve patient safety are required. The present brief review analyses specific problems of airway management related to difficult tracheal intubation and to difficult mask ventilation prediction. The review will focus on basic airway management including preoxygenation, and on some oxygenation and tracheal intubation techniques that may be performed to solve a difficult airway.

Background: Plastic single-use laryngoscope blades are inexpensive and carry a lower risk of infection compared with metal reusable blades, but their efficiency during rapid sequence induction remains a matter of debate. The authors therefore compared plastic and metal blades during rapid sequence induction in a prospective randomized trial., Methods: Two hundred eighty-four adult patients undergoing general anesthesia requiring rapid sequence induction were randomly assigned on a weekly basis to either plastic single-use or reusable metal blades (cluster randomization). After induction, a 60-s period was allowed to complete intubation. In the case of failed intubation, a second attempt was performed using metal blade. The primary endpoint of the study was the rate of failed intubations, and the secondary endpoint was the incidence of complications (oxygen desaturation, lung aspiration, and oropharynx trauma)., Results: Both groups were similar in their main characteristics, including risk factors for difficult intubation. On the first attempt, the rate of failed intubation was significantly increased in plastic blade group (17 vs. 3%; P < 0.01). In metal blade group, 50% of failed intubations were still difficult after the second attempt. In plastic blade group, all initial failed intubations were successfully intubated using metal blade, with an improvement in Cormack and Lehane grade. There was a significant increase in the complication rate in plastic group (15 vs. 6%; P < 0.05)., Conclusions: In rapid sequence induction of anesthesia, the plastic laryngoscope blade is less efficient than a metal blade and thus should not be recommended for use in this clinical setting.