Major complications of airway management: a prospective multicentre observational study

We conducted an observational study of serious airway complications, using similar methods to the fourth UK National Audit Project (NAP4) over a period of 1 year across four hospitals in one region in the UK. We also conducted an activity survey over a week, using NAP4 methods to yield an estimate for relevant denominators to help interpret the primary data. There were 17 serious airway complications, defined as: failed airway management leading to cancellation of surgery (eight); airway management in recovery (five); unplanned intensive care admission (three); and unplanned emergency front of neck access (one). There were no reports of death or brain damage. This was an estimate of 0.028% (1 in 3600) complications using the denominator of 61,000 general anaesthetics per year in the region. Complications in patients with ‘predicted easy’ airways were rare (approximately 1 in 14,200), but 45 times more common in those with ‘predicted difficult’ airways (approximately 1 in 315). Airway management in both groups was similar (induction of anaesthesia followed by supraglottic airway or tracheal tube). Use of awake/sedation intubation, videolaryngoscopy and high-flow nasal oxygenation were uncommon even in the predicted difficult airway patients (in 2.7%, 32.4% and 9.5% of patients, respectively). We conclude that the incidence of serious airway complications is at least as high as it was during NAP4. Despite airway prediction being used, this is not informing subsequent management.     

Using a nasopharyngeal airway during fiberoptic intubation in small children with a difficult airway

BACKGROUND: Induction of anesthesia and tracheal intubation in small children with a difficult airway is a challenging task. We report the experience with a procedure based on sevoflurane inhalation via a nasopharyngeal airway inserted early during induction before airway obstruction occurs. A pediatric fiberscope is used to perform a nasotracheal intubation via the opposite nostril. METHODS: All small children with suspected or known difficult airway needing tracheal intubation were scheduled for a fiberoptic intubation following the described protocol. RESULTS: In 3 years, we performed 27 successful fiberoptic guided tracheal intubations in 19 children, median age 8.2 months (1.0-39.1 months) and median weight 7.6 kg (3.0-15.0 kg). The optimal depth for placement of the nasopharyngeal airway was found to be 8.0 cm (7.0-8.5 cm) from the nostril in the first year of life and 8.5 cm (8.0-10 cm) in the second year. Oxygenation was sufficient during the entire procedure in all cases except one child who had short-lasting laryngeal spasm caused by instillation of lidocaine during light anesthesia. The duration of fiberoptic intubation was significantly shorter when performed by an experienced anesthesiologist (55 s vs. 120 s), but there was no significant correlation between the duration of fiberoscopy and oxygen saturation during fiberoscopy or endtidal CO(2) after intubation. CONCLUSION: The combination of nasopharyngeal airway and fiberoptic guided tracheal intubation seems to be a reliable and safe procedure for managing the difficult airway in small children.     

Intubating laryngeal mask airway for difficult out-of-hospital airway management: a prospective evaluation

Background: Out-of-hospital airway management is a critical skill, demandingexpert knowledge and experience. The intubating laryngeal maskairway (ILMA) is a ventilatory and intubating device which maybe of value in this arena. We evaluated the ILMA for out-of-hospitalmanagement of the difficult airway. Methods: Twenty-one anaesthesia-trained emergency physicians (EPs) completeda training programme and used the ILMA in patients with difficult-to-manageairways. Indications for use of the ILMA included patients withdifficult laryngoscopy, multiple intubation attempts, limitedaccess to the patient’s head, presence of pharyngo-laryngealtrauma, and gastric fluids or bleeding obscuring the view ofthe vocal cords. Results: During the study period, 146 of 2513 patients underwent trachealintubation or alternate rescue airway insertion. In 135 patients,laryngoscopy was performed and Cormack–Lehane view wasrecorded as grade I in 72 (53.3%), II in 45 (33.3%), III in10 (7.4%), and IV in 8 (5.9%). EPs encountered 11 patients (7.5%)with difficult-to-manage airways. ILMA insertion and ventilationwas possible in 10 patients in the first and one patient inthe second attempt. ILMA-guided tracheal intubation was successfulin all patients, in 10 after the first and in 1 after two attempts. Conclusions: In this study, ventilation and intubation with ILMA was successfulin all patients with difficult-to-manage airways. Our data supportthe use of the ILMA as rescue device for out-of-hospital airwaymanagement by staff who have appropriate airway skills and havereceived appropriate training.     

Simple solution for difficult face mask ventilation in children with orofacial clefts

Significant air leak from the facial cleft predisposes to difficult mask ventilation. The reported techniques of use of sterile gauze, larger face mask and laryngeal mask airway after intravenous induction have limited application in uncooperative children. We describe the use of dental impression material molded to the facial contour to cover the facial defect and aid ventilation with an appropriate size face mask in a child with a bilateral Tessier 3 anomaly.     

The laryngeal mask airway in the difficult paediatric airway: an assessment of positioning and use in fibreoptic intubation

The laryngeal mask airway (LMA) was used in 34 children who presented with difficult airways and difficulty in intubation. All 34 children were a grade 3 or grade 4 Cormack and Leehane view at conventional laryngoscopy. The laryngeal mask airway was used as part of the anaesthetic technique. It was either used as the method of airway maintenance during a short procedure or as an aid to fibreoptic intubation. The results of its use in this group of patients showed that overall a good airway was obtained in 73% of patients and an adequate airway in 27%, and in no patient was a poor airway obtained. The fibreoptic positioning of the LMA, taken from the distal aperture of the laryngeal mask airway showed that, overall, in 29.5% of patients a full view of the glottis (grade 1) was obtained, in 29.5% of patients a partial view of the glottis (grade 2) was obtained and in 41% a view of the epiglottis only (grade 3) was obtained. In no patient was a view excluding the epiglottis obtained. In children with a mucopolysaccharide disorder, the number of children who had a grade 3 view increased to 54%. Children with a disorder other than mucopolysaccharidosis had a grade 3 view in only 17% of cases. Children with mucopolysaccharidoses had a grade 1 view in only 14% of cases compared with 58% in the group with other disorders. Of the 34 patients, 21 patients were intubated on 31 separate occasions. There were no failures. The complications of the fibreoptic intubation technique described are outlined.     

A left paraglossal approach for oral intubation in children scheduled for bilateral orofacial cleft reconstruction surgery – a prospective observational study

Background: Children with orofacial cleft defects are expected to have difficult airways. Conventional midline laryngoscopic approach of oral intubation can lead to iatrogenic tissue trauma. In this study, we evaluated the feasibility of left paraglossal laryngoscopy as a primary technique for airway management in these children. Methods: After institutional ethical committee approval and informed consent, we enrolled 21 children with uncorrected bilateral lip and palate deformities (BL CL/P). Anesthesia was induced with halothane (0.5–4%) in 100% oxygen. After obtaining intravenous access, fentanyl 1.5 μg·kg^?1 and atracurium 0.5 mg·kg^?1 were administered. Endotracheal intubation was performed with Miller’s straight blade laryngoscope, introduced using left paraglossal approach. Difficulty of intubation was scored according to modified Intubation Difficulty Scale. Results: Data consists of 21 children (15 males and six females), mean age 1.31 ± 1.18 years and weight 9.27 ± 2.57 kg. Laryngoscopic view obtained was CL II (7[33.3%]) and CL I (14[66.6%]) respectively ( Figure 1 ). All the children could be easily intubated using left paraglossal approach, only 2/3 of them needed optimal external laryngeal manipulation to help achieving it. Though intubation could be done in the first attempt in 19 children, two infants (9½ and 11 months) required one size smaller endotracheal tube and were intubated in the second attempt using left paraglossal approach. Perioperative course was uneventful in all the children.

Figure 1 Open in figure viewer PowerPoint Distribution of Intubation Difficulty scale (IDS) Score in BL CL/P patients. n (%) IDS: 0 (intubation without difficulty), IDS: 1 (slight difficulty; OELM applied/additional intubation attempt), IDS: >5 (Moderate to Major difficulty), IDS: = α (Impossible intubation).     

The Management of difficult intubation in children

This article looks at the current techniques and equipment recommended for the management of the difficult intubation scenario in pediatric practice. We discuss the general considerations including preoperative preparation, the preferred anesthetic technique and the use of both rigid laryngoscopic and fiberoptic techniques for intubation. The unanticipated scenario is also discussed.     

Continuous ventilation technique for laryngeal mask airway (LMA) removal after fiberoptic intubation in children

BACKGROUND: Fiberoptic tracheal intubation through the laryngeal mask airway (LMA) is a simple technique to establish a safe airway in neonates and infants with a difficult airway. The technique, however, is complicated by the removal of the laryngeal mask from the patient's mouth because of the similarity in length of the LMA and the tracheal tube. METHODS: Several solutions have been presented to stabilize the tracheal tube within the trachea during withdrawal of the LMA. With all these techniques ventilation of the patient is interrupted. RESULTS: We present a modified technique, using a double tube assembly, which allows uninterrupted ventilation of the patient during withdrawal of the LMA from the patient's mouth. CONCLUSIONS: The technique is simple and safe, can be performed without hurry and carries potential advantages for neonates and children with limited cardiorespiratory reserve.     

困难气道及其预测

1何谓困难气道作为麻醉科医生在插管前应该能准确的预测潜在的困难气道并提前做好充分的准备。Ezri等[1]认为所谓的困难气道应该从通气,喉镜暴露或是气管插管来决定。通气困难意为当吸入纯氧且正压通气时不能维持氧饱和度达90%以上。困难暴露意为用喉镜暴露声门时不能看见声门的任何结构。困难插管则指经3次以上的试插或是插管时间超过10min。而ASA[2]定义为当一名受过良好训练的麻醉科医生在管理病人气道时仍面临了困难的通气,插管,或是安置喉罩的这种临床情形,则可称为困难气道。2发生困难气道的原因大致可分为两种情况,一个是医源性的,…     

Facemask ventilation and vocal cord angle following neuromuscular blockade: a prospective observational study#

Numerous studies support the idea that neuromuscular blockade facilitates facemask ventilation after induction of anaesthesia. Although improved airway patency or pulmonary compliance and a resolution of laryngospasm have been suggested as possible causes, the exact mechanism remains unclear. We aimed to assess whether neuromuscular blockade improves facemask ventilation and to clarify whether this phenomenon is associated with the vocal cord angle. This prospective observational study included patients aged between 20 and 65 years scheduled for elective surgery under general anaesthesia. After induction of anaesthesia, patients' lungs were ventilated with pressure-controlled ventilation using a facemask. During facemask ventilation, a flexible bronchoscope was inserted through a self-sealing diaphragm at the elbow connector attached to the facemask and breathing circuit and positioned to allow a continuous view of the vocal cords. The mean tidal volume and vocal cord angle were measured before and after administration of neuromuscular blocking drugs. Of 108 patients, 100 completed the study. Mean (SD) tidal volume ((11.0 (3.9) ml.kg^-1 vs. 13.6 (2.6) ml.kg^-1; p < 0.001) and mean (SD) vocal cord angle (17° (10°) vs. 26° (5°); p < 0.001) increased significantly after neuromuscular blockade. The proportional increase in mean tidal volume after neuromuscular blockade was positively correlated with vocal cord angle (Spearman's ρ = 0.803; p < 0.001). In conclusion, neuromuscular blockade facilitated facemask ventilation, and the improvement was correlated with further opening of the vocal cords.     

Use of a ProSeal laryngeal mask airway for airway maintenance during emergency Caesarean section after failed tracheal intubation

We report the use of the ProSeal^TM laryngeal mask airway toestablish and maintain the airway during emergency Caesareansection when tracheal intubation had failed with conventionallaryngoscopy and mask ventilation was difficult. The ProSeal^TMlaryngeal mask allowed controlled ventilation without gas leakand facilitated drainage of the stomach. Br J Anaesth 2004; 92: 144–6     

Airway events in obese vs. non-obese elective surgical patients: a cross-sectional observational study

Obesity is an increasingly prevalent comorbidity within the UK population. The aim of this study was to determine the proportion of obese patients in an elective surgical population. The second aim was to determine the choice of airway equipment and incidence of airway events in obese vs. non-obese patients. We conducted a cross-sectional observational study over two 24-h periods in March 2018 across 39 hospitals in the greater London area. Data were collected regarding 1874 patients. The incidence of obesity was 32% in the study population compared with 26% in the general UK population (p < 0.0001). Minor airway events were defined as: desaturation to S_pO₂ < 90%; failed mask ventilation; supraglottic airway device problem; aspiration; airway trauma and difficult intubation; or recognised oesophageal intubation. Major airway events were defined as: unrecognised oesophageal intubation; a ‘cannot intubate cannot oxygenate’ emergency; the need for unplanned front-of-neck airway; cardiac arrest; or unplanned intensive care unit admission due to an airway event. In total, 89 minor and two major airway events were recorded. Obese patients were more likely to experience a minor airway event (RR 2.39, 95%CI 1.60–3.57), the most common being desaturation (S_pO₂ < 90%). The use of a supraglottic airway device in obese vs. non-obese patients was associated with increased airway events (RR 3.46 [1.88–6.40]). Tracheal intubation vs. supraglottic airway device use increased with obesity class but was not associated with a decrease in airway events (RR 0.90 [0.53–1.55]). Our data suggest that obesity is more common in the elective surgical vs. general population and minor airway events are more common in obese vs. non-obese elective patients.     

The effect of neuromuscular blockade on the efficiency of facemask ventilation in patients difficult to facemask ventilate: a prospective trial

Facemask ventilation of the lungs can be an important rescue intervention in a ‘cannot intubate’ scenario. We assessed the effect of neuromuscular blockade on expiratory tidal volumes in patients with expected difficulty in mask ventilation. The lungs of patients with at least three predictors of difficulty in mask ventilation were ventilated using a facemask held with two hands, with mechanical ventilation set in a pressure‐controlled mode. Tidal volumes were recorded before and after the establishment of complete neuromuscular block. In 113 patients, median (IQR [range]) tidal volume increased from 350 (260–492 [80–850]) ml initially, by 48% to 517 (373–667 [100–1250]) ml 30 s after rocuronium administration, (p < 0.001). After the onset of the complete neuromuscular block, a median tidal volume of 600 (433–750 [250–1303]) ml was observed, corresponding to an increase of 71% from baseline values (p < 0.001), and 16% from values obtained 30 s after rocuronium administration, respectively; p = 0.003). No decrease in the tidal volume during the measurements was observed. We conclude that the administration of rocuronium at a dose of 0.6 mg.kg^?1 was able to improve facemask ventilation in all cases with a potentially clinically relevant increase in tidal volume. The early use of a neuromuscular blocking agent can be considered as a therapeutic option in case of difficulty with mask ventilation.     

Identification of the difficult airway

Nearly all patients who are seriously difficult to manage are easily identified because they have grossly obvious abnormalities. Conversely, it is difficult to identify the few normal-looking patients that are difficult to manage.     

Incidence and predictors of difficult laryngoscopy in 11.219 pediatric anesthesia procedures

Objective: Difficult laryngoscopy in pediatric patients undergoing anesthesia. Aim: This retrospective analysis was conducted to investigate incidence and predictors of difficult laryngoscopy in a large cohort of pediatric patients receiving general anesthesia with endotracheal intubation. Background: Young age and craniofacial dysmorphy are predictors for the difficult pediatric airway and difficult laryngoscopy. For difficult laryngoscopy, other general predictors are not yet described. Methods: Retrospectively, from a 5‐year period, data from 11.219 general anesthesia procedures in pediatric patients with endotracheal intubation using age‐adapted Macintosh blades in a single center (university hospital) were analyzed statistically. Results: The overall incidence of difficult laryngoscopy [Cormack and Lehane (CML) grade III and IV] was 1.35%. In patients younger than 1 year, the incidence of CML III or IV was significantly higher than in the older patients (4.7% vs 0.7%). ASA Physical Status III and IV, a higher Mallampati Score (III and IV) and a low BMI were all associated (P < 0.05) with difficult laryngoscopy. Patients undergoing oromaxillofacial surgery and cardiac surgery showed a significantly higher rate of CML III/IV findings. Conclusion: The general incidence of difficult laryngoscopy in pediatric anesthesia is lower than in adults. Our results show that the risk of difficult laryngoscopy is much higher in patients below 1 year of age, in underweight patients and in ASA III and IV patients. The underlying disease might also contribute to the risk. If the Mallampati score could be obtained, prediction of difficult laryngoscopy seems to be reliable. Our data support the existing recommendations for a specialized anesthesiological team to provide safe anesthesia for infants and neonates.     

Supraglottic airway devices in difficult airway management: a retrospective cohort study of 658,104 general anaesthetics registered in the Danish Anaesthesia Database

Indications for using supraglottic airway devices have widened over time and they now hold a prominent role in guidelines for difficult airway management. We aimed to describe the use of supraglottic airway devices in difficult airway management. We included adult patients undergoing general anaesthesia registered in the Danish Anaesthesia Database from 2008 to 2012 whose airway management had been recorded as difficult, defined as: ≥ 3 tracheal intubation attempts; failed tracheal intubation; or difficult facemask ventilation. In the Danish Anaesthesia Database, a separate difficult airway management module requires the technique used in each successive airway management attempt to be recorded. The primary aim of the study was to describe the use of supraglottic airway devices in cases of difficult airway management. Secondary aims were to examine success rates of supraglottic airway devices in difficult airway management cases, and specifically in the cases of ‘cannot intubate, cannot facemask ventilate’. Difficult airway management occurred in 4898 (0.74% (95%CI 0.72–0.76%)) of 658,104 records of general anaesthesia. Supraglottic airway devices were used or use was attempted in 607 cases of difficult airway management (12.4% (95%CI 11.5–13.3%)), and were successful in 395 (65.1% (95%CI 61.2–68.8%)) cases. In ‘cannot intubate, cannot facemask ventilate’ situations, supraglottic airway devices were used in 86 (18.9% (95%CI 15.6–22.8%)) of 455 records and were successful in 54 (62.8% (95%CI 52.2–72.3%)) cases. We found that supraglottic airway devices are not widely used in the management of the difficult airway despite their prominent role in difficult airway management guidelines.