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.     

Präklinische Intubation

Endotracheal intubation is required in 5–10% of all prehospital emergencies. Poor environmental conditions (e.g. limited space, poor or excessive lighting etc.), unfavorable patient-related factors (e.g. trauma, bleeding, pulmonary aspiration etc.) and the pressure of time make prehospital airway management a challenging procedure even for experienced emergency physicians. The incidence of difficult endotracheal intubation is significantly higher than in-hospital. Profound clinical practice, recognition and adequate treatment of complications of intubation, and ongoing clinical practice are essential for successful and responsible prehospital airway management. A brief physical examination helps to identify predictors for difficult intubation, thereby modifying treatment strategies. Every emergency physician must be closely familiar with at least one supraglottic airway device and the recent algorithms to manage the unanticipated difficult airway.     

Emergency endotracheal intubation in pediatric trauma.

The purpose of this study was to determine the effectiveness and associated problems of emergency intubation in 605 injured infants and children admitted to the Children's Hospital of Pittsburgh in 1987. We identified 63 patients (10.4%) undergoing endotracheal intubation at the scene of injury, at a referring hospital or in our emergency department. Injuries were to the head (90.5%), abdomen (12.7%), face (11.1%), chest (6.3%), neck (3.2%); or were orthopedic (19%) or multiple (39.7%). Indications for intubation included coma (74.6%), shock (28.6%), apnea (22.2%), and airway obstruction (3.2%). Of 16 complications (25.4%), 13 were immediately life threatening: right mainstem intubation (5), massive barotrauma (2), failure of adequate preoxygenation (2), esophageal intubation (1), attempt at nasotracheal intubation in an open facial fracture (1), and extubation during transport (1). Three were late complications: vocal cord paresis (2) and subglottic stenosis (1). Airway complications led to PO2 less than 90 mm Hg in 7 of 12 on first ABG, compared to 9 of 44 in uncomplicated cases (p less than 0.05). Intubation attempts at the scene of injury were more often multiple, unsuccessful, and associated with airway complications. All four complication-associated fatalities were life-threatening scene complications. Nearly one half (44.4%, 28 of 63) had one of the following problems in respiratory management: major airway complication, PaO2 less than 90, or PaCO2 greater than 45 on either the first or second ABG after arrival at our emergency department. Head injury with coma is the most common setting for emergency intubation. Airway complications are common, and are more frequent in treatment attempt at the scene. Despite endotracheal intubation, injured children in our series remain at high risk for hypoxemia, elevated arterial PCO2, and major airway complications, all of which contribute to secondary brain injury.     

Failed tracheal intubation during obstetric general anaesthesia: a literature review

We reviewed the literature on obstetric failed tracheal intubation from 1970 onwards. The incidence remained unchanged over the period at 2.6 (95% CI 2.0 to 3.2) per 1000 anaesthetics (1 in 390) for obstetric general anaesthesia and 2.3 (95% CI 1.7 to 2.9) per 1000 general anaesthetics (1 in 443) for caesarean section. Maternal mortality from failed intubation was 2.3 (95% CI 0.3 to 8.2) per 100 000 general anaesthetics for caesarean section (one death per 90 failed intubations). Maternal deaths occurred from aspiration or hypoxaemia secondary to airway obstruction or oesophageal intubation. There were 3.4 (95% CI 0.7 to 9.9) front-of-neck airway access procedures (surgical airway) per 100 000 general anaesthetics for caesarean section (one procedure per 60 failed intubations), usually carried out as a late rescue attempt with poor maternal outcomes. Before the late 1990s, most cases were awakened after failed intubation; since the late 1990s, general anaesthesia has been continued in the majority of cases. When general anaesthesia was continued, a laryngeal mask was usually used but with a trend towards use of a second-generation supraglottic airway device. A prospective study of obstetric general anaesthesia found that transient maternal hypoxaemia occurred in over two-thirds of cases of failed intubation, usually without sequelae. Pulmonary aspiration occurred in 8% but the rate of maternal intensive care unit admission after failed intubation was the same as that after uneventful general anaesthesia. Poor neonatal outcomes were often associated with preoperative fetal compromise, although failed intubation and lowest maternal oxygen saturation were independent predictors of neonatal intensive care unit admission.     

Évaluation de l'apprentissage d'un nouveau guide lumineux (trachlight™) pour l'intubation trachéale

ObjectiveTo assess the learning curve of a new lightwand device, Trachlight^™ (Laerdal), for blind orotracheal intubation in patients without foreseen difficulty in airway management.Study designOpen, prospective, clinical study.UsersTwelve persons practicing anaesthesia (specialists, trainees, nurses) underwent videotape learning and manikin training with ten successful intubation manoeuvres required with the device.MethodsEach person had to carry out a tracheal intubation in ten consecutive patients undergoing scheduled surgery and without history or clinical sign of difficults airway management.ResultsOne hundred and twenty patients were included. The overall success rate with the Trachlight^™ was 87%. An easy learning curve was obtained as demonstrated by the low failure rate in the first three patients, and by the success rate on the first or second attempt in the last four patients. There was no significant difference in failure rate with or without muscle relaxation (10 vs 20%, NS). Finally, all failures with the Trachlight^™ were followed by successful intubation using direct laryngoscopy, and no traumatic complications were recorded with the device.ConclusionTrachlight^™ is a new lightwand device enabling blind tracheal intubation with an easy learning curve in patients without difficulty in airway management, even for non-selected operators.     

Monitoring during difficult airway management

Monitoring is crucial to assure safety during difficult airway management. Several reports have indicated that the most of the adverse outcomes associated with difficult airway management could have been avoided with the use of necessary monitors, such as a pulse oximeter and a capnometer. Nevertheless, airway complications continue to be major problems during anesthesia, in particular, in patients with difficult airways. In this brief review, I stress the role of monitoring in detecting inadvertent esophageal intubation, during sedation for awake tracheal intubation, during general anesthesia, and during emergence from anesthesia, in patients with difficult airways.     

Airway management for cesarean delivery performed under general anesthesia

BackgroundWith the increasing popularity of neuraxial anesthesia, there has been a decline in the use of general anesthesia for cesarean delivery. We sought to examine the incidence, outcome and characteristics associated with a failed airway in patients undergoing cesarean delivery under general anesthesia.MethodsA retrospective review of airway management in women undergoing cesarean delivery under general anesthesia over an eight-year period from 2006–2013 at an academic medical center was conducted.ResultsDuring the study period, 10 077 cesarean deliveries were performed. Neuraxial anesthesia was used in 9382 (93%) women while general anesthesia was used in 695 (7%). Emergent cesarean delivery was the most common indication for general anesthesia. Failed intubation was encountered in only three (0.4%) women, who were successfully managed with a laryngeal mask airway. The overall incidence of failed intubation was 1 in 232 (95% CI 1:83 to 1:666) and general anesthesia was continued in all cases. There were no adverse maternal or fetal outcomes directly related to failed intubation.ConclusionAdvances in adjunct airway equipment, availability of an experienced anesthesiologist and simulation-based teaching of failed airway management in obstetrics may have contributed to our improved maternal outcomes in patients undergoing cesarean delivery under general anesthesia.     

Airway complications of infant botulism: ten-year experience with 60 cases.

OBJECTIVE: The study goal was to understand the incidence, etiology, and management of airway complications in infant botulism. METHODS: We conducted a retrospective review of the period from January 1, 1987, to December 31, 1997. SETTING: Urban tertiary care children's hospital. RESULTS: Of 60 children with infant botulism, 37 (61.7%) required endotracheal intubation for a mean of 21 days. No patient required a tracheostomy. Airway complications (stridor, subglottic stenosis, granuloma formation) occurred in 5 (13.5%) of 37 patients, with 3 requiring surgical bronchoscopy. Of the 37 children, 14 (37.8%), including 4 with airway complications, had endotracheal tube leak pressures recorded. In 3 (50%) of 6 patients with measured leak pressures of greater than 40 cm H2O, airway complications developed. Complications did not develop in patients with leak pressures of less than 20 cm H2O. No correlation between length of intubation and complications could be established. CONCLUSION: Airway complications in infant botulism may be accompanied by high leak pressures and can be managed with endoscopic techniques. The study data suggest that leak pressures should be measured on a regular basis and maintained at less than 20 to 25 cm H2O. A prospective trial to study this issue is warranted. Tracheotomy is not routinely necessary. A high index of suspicion, early diagnosis, and prompt intervention are required for the optimal management of airway complications in infant botulism.     

Blind nasotracheal intubation for patients with penetrating neck trauma

BACKGROUND: Early airway management is advocated for patients with penetrating neck trauma who have any signs of airway compromise. This study examined the clinical course of patients with penetrating neck trauma who received prehospital blind nasotracheal intubation, including successful intubation rates, and outcomes. METHODS: A retrospective review of patients admitted to the emergency department for penetrating neck trauma was conducted from January 1, 1993 to July 1, 2001 at the Denver Health Medical Center. Patients were identified from the trauma registry, and data were collected using standardized inclusion and exclusion criteria. RESULTS: The study identified 240 patients with penetrating neck trauma. Overall mortality was 8.3%. Among the 240 patients, 89 (37%) required airway management, and 40 (17%) underwent prehospital management with blind nasotracheal intubation. The success rate for prehospital intubation using the blind nasotracheal method was 90%. The mean number of attempts was 1.16 (range, 1-4), and the mortality in this group was 5%. CONCLUSION: The patients managed with blind nasotracheal intubation did not experience complications related to the choice of airway management. Despite prior warnings in the literature, the results of this study suggest that blind nasotracheal intubation may well be a valuable tool for the management of patients with penetrating neck trauma.     

Complications associated with paediatric airway management during the COVID-19 pandemic: an international,multicentre, observational study

Respiratory adverse events in adults with COVID-19 undergoing general anaesthesia can be life-threatening. However, there remains a knowledge gap about respiratory adverse events in children with COVID-19. We created an international observational registry to collect airway management outcomes in children with COVID-19 who were having a general anaesthetic. We hypothesised that children with confirmed or suspected COVID-19 would experience more hypoxaemia and complications than those without. Between 3 April 2020 and 1 November 2020, 78 international centres participated. In phase 1, centres collected outcomes on all children (age ≤ 18 y) having a general anaesthetic for 2 consecutive weeks. In phase 2, centres recorded outcomes for children with test-confirmed or suspected COVID-19 (based on symptoms) having a general anaesthetic. We did not study children whose tracheas were already intubated. The primary outcome was the incidence of hypoxaemia during airway management. Secondary outcomes included: incidence of other complications; and first-pass success rate for tracheal intubation. In total, 7896 children were analysed (7567 COVID-19 negative and 329 confirmed or presumed COVID-19 positive). The incidence of hypoxaemia during airway management was greater in children who were COVID-19 positive (24 out of 329 (7%) vs. 214 out of 7567 (3%); OR 2.70 (95%CI 1.70–4.10)). Children who had symptoms of COVID-19 had a higher incidence of hypoxaemia compared with those who were asymptomatic (9 out of 51 (19%) vs. 14 out of 258 (5%), respectively; OR 3.7 (95%CI 1.5–9.1)). Children with confirmed or presumed COVID-19 have an increased risk of hypoxaemia during airway management in conjunction with general anaesthesia.     

Death and Other Complications of Emergency Airway Management in Critically Ill Adults: A Prospective Investigation of 297 Tracheal Intubations

Background: Hospitalized patients outside of the operating room frequently require emergency airway management. This study investigates complications of emergency airway management in critically ill adults, including: (1) the incidence of difficult and failed intubation; (2) the frequency of esophageal intubation; (3) the incidence of pneumothorax and pulmonary aspiration; (4) the hemodynamic consequences of emergent intubation, including death, during and immediately following intubation; and (5) the relationship, if any, between the occurrence of complications and supervision of the intubation by an attending physician.

Methods: Data were collected on consecutive tracheal intubations carried out by the intensive care unit team over a 10-month period. Non-anesthesia residents were supervised by anesthesia residents, critical care attending physicians, or anesthesia attending physicians.

Results: Two hundred ninety-seven consecutive intubations were carried out in 238 adult patients. Translaryngeal tracheal intubation was accomplished in all patients. Intubation was difficult in 8% of cases (requiring more than two attempts at laryngoscopy by a physician skilled in airway management). Esophageal intubation occurred in 25 (8%) of the attempts but all were recognized before any adverse sequelae resulted. New infiltrates suggestive of pulmonary aspiration were present on chest radiograph after 4% of intubations. Seven patients (3%) died during or within 30 min of the procedure. Five of the seven patients had systemic hypotension (systolic blood pressure less or equal to 90 mmHg), and four of the five were receiving vasopressors to support systolic blood pressure. Patients with systolic hypotension were more likely to die after intubation than were normotensive patients (P < 0.001). There was no relationship between supervision by an attending physician and the occurrence of complications.     

Difficult and failed intubation in 3430 obstetric general anaesthetics*

A retrospective audit was performed of all obstetric general anaesthetics in our hospital over an 8 year period to determine the incidence of difficult and failed intubation. Data was collected from a number of sources to ensure accuracy. A total of 3430 rapid sequence anaesthetics were given. None of the patients had a failed or oesophageal intubation (95% CI, 0–1:1143). There were 23 difficult intubations (95% CI, 1:238–1:100). This was anticipated in nine cases, requiring awake fibreoptic intubation in three cases. Consultants or specialist registrars were involved in the management of all cases. We attribute the low incidence of airway complications to the above average rate of general anaesthesia in our hospital, senior cover and specialised anaesthetic operating department assistants.     

Postoperative pulmonary complications in older patients undergoing elective surgery with a supraglottic airway device or tracheal intubation

The two most commonly used airway management techniques during general anaesthesia are supraglottic airway devices and tracheal tubes. In older patients undergoing elective non-cardiothoracic surgery under general anaesthesia with positive pressure ventilation, we hypothesised that a composite measure of in-hospital postoperative pulmonary complications would be less frequent when a supraglottic airway device was used compared with a tracheal tube. We studied patients aged ≥ 70 years in 17 clinical centres. Patients were allocated randomly to airway management with a supraglottic airway device or a tracheal tube. Between August 2016 and April 2020, 2900 patients were studied, of whom 2751 were included in the primary analysis (1387 with supraglottic airway device and 1364 with a tracheal tube). Pre-operatively, 2431 (88.4%) patients were estimated to have a postoperative pulmonary complication risk index of 1–2. Postoperative pulmonary complications, mostly coughing, occurred in 270 of 1387 patients (19.5%) allocated to a supraglottic airway device and 342 of 1364 patients (25.1%) assigned to a tracheal tube (absolute difference −5.6% (95%CI −8.7 to −2.5), risk ratio 0.78 (95%CI 0.67–0.89); p < 0.001). Among otherwise healthy older patients undergoing elective surgery under general anaesthesia with intra-operative positive pressure ventilation of their lungs, there were fewer postoperative pulmonary complications when the airway was managed with a supraglottic airway device compared with a tracheal tube.     

Awake fibrecapnic intubation: a novel technique for intubation in head and neck cancer patients with a difficult airway

Awake fibreoptic intubation is the gold standard for difficult airway management but failures are reported in the literature in up to 13% of cases. In case of failure, a tracheotomy is often indicated. We describe a novel technique for intubation in head and neck cancer patients with a difficult airway that we call awake fibrecapnic intubation. The aim of this study was to investigate the feasibility of this technique. We studied prospectively 15 consecutive intubations in head and neck cancer patients before diagnostic or therapeutic surgical procedures. After topical anaesthesia, a fibrescope was introduced into the pharynx. Spontaneous respiration was maintained in all patients. Through the suction channel of the fibrescope a special suction catheter was advanced into the airway for carbon dioxide measurements. When four capnograms were obtained, the fibrescope was railroaded over the catheter and after identification of tracheal rings, a tracheal tube was placed. Tracheal intubation was successful in all patients without bleeding or complications, with a median (range) time to intubation of 3 (2-15) min. Identification of the vocal cords and glottis was difficult in four patients due to extensive anatomical abnormalities or poor visibility; even in these patients, a capnogram was obtained within 4 s.     

Hypoxaemia during tracheal intubation in patients with hypertensive disorders of pregnancy: analysis of data from an obstetric airway management registry

BackgroundIn South Africa, hypertensive disorders of pregnancy are the leading cause of maternal mortality. More than 50% of anaesthesia-related maternal deaths are attributed to complications of airway management. We compared the prevalence and risk factors for hypoxaemia during induction of general anaesthesia in parturients with and without hypertensive disorders of pregnancy. We hypothesised that hypertensive disorders of pregnancy are associated with desaturation during tracheal intubation.MethodsData from 402 cases in a multicentre obstetric airway management registry were analysed. The prevalence of peri-induction hypoxaemia (SpO₂ <90%) was compared in patients with and without hypertensive disorders of pregnancy. Quantile regression of SpO₂ nadir was performed to identify confounding variables associated with, and mediators of, hypoxaemia.ResultsIn the cohort of 402 cases, hypoxaemia occurred in 19% with and 9% without hypertension (estimated risk difference, 10%; 95% CI 2% to 17%; P=0.005). Quantile regression demonstrated a lower SpO₂ nadir associated with hypertensive disorders of pregnancy as body mass index increased. Room-air oxygen saturation, Mallampati grade, and number of intubation attempts were associated with the relationship.ConclusionsClinically significant oxygen desaturation during airway management occurred twice as often in patients with hypertensive disorders of pregnancy, compounded by increasing body mass index. Intermediary factors in the pathway from hypertension to hypoxaemia were also identified.     

A comparative study of tracheal intubation using an intubating laryngeal mask (Fastrach) alone or together with a lightwand (Trachlight)

Study Objective: To determine if the Trachlight^TM lightwand can facilitate Fastrach^TM intubation by guiding the tip of the endotracheal tube into the trachea.

Design: Open-label, prospective, randomized, comparative study.

Setting: General operating suites of a tertiary teaching hospital.

Patients: 172 elective surgical patients requiring general anesthesia with endotracheal intubation.

Interventions: With general anesthesia, the Fastrach™, which is a new intubating laryngeal mask airway, was inserted into the oropharynx. Ventilation was ensured before the insertion of an endotracheal tube via the Fastrach™. Tracheal intubation was then performed randomly (coin toss) using either the endotracheal tube alone (Fastrach™ group), or endotracheal tube with the Trachlight, a lightwand (Fastrach/Trachlight™ group). The time to place the Fastrach™ and endotracheal tube, to remove the Fastrach™, and the total time to intubate were recorded. The number of attempts, failures, trauma, sore throats, and hemodynamic changes were also recorded. Data were analyzed using unpaired t-test, ANOVA with repeated measures, or Chi-squares contingency table where appropriate.

Measurements and Main Results: Although there were no differences in the times to place the Fastrach™, and endotracheal tube, the hemodynamic changes, and postoperative complications, there were significantly more attempts and failures in the Fastrach™ group compared to the Fastrach™/Trachlight™ group. There were no differences in the incidence of sore throat and trauma in between the groups.

Conclusions: Although tracheal intubation is effective using a Fastrach™ alone (76% success rate), it is more effective when the Fastrach™ is used in conjunction with the Trachlight™ (95%). These results suggest that the lightwand is a useful adjunct for Fastrach™ intubation. However, the role of Fastrach™ intubation together with the Trachlight™ in the management of patients with a potential difficult airway remains to be determined.     

Airway management during spaceflight: A comparison of four airway devices in simulated microgravity

BACKGROUND: The authors compared airway management in normogravity and simulated microgravity with and without restraints for laryngoscope-guided tracheal intubation, the cuffed oropharyngeal airway, the standard laryngeal mask airway, and the intubating laryngeal mask airway. METHODS: Four trained anesthesiologist-divers participated in the study. Simulated microgravity during spaceflight was obtained using a submerged, full-scale model of the International Space Station Life Support Module and neutrally buoyant equipment and personnel. Customized, full-torso manikins were used for performing airway management. Each anesthesiologist-diver attempted airway management on 10 occasions with each device in three experimental conditions: (1) with the manikin at the poolside (poolside); (2) with the submerged manikin floating free (free-floating); and (3) with the submerged manikin fixed to the floor using a restraint (restrained). Airway management failure was defined as failed insertion after three attempts or inadequate device placement after insertion. RESULTS: For the laryngoscope-guided tracheal intubation, airway management failure occurred more frequently in the free-floating (85%) condition than the restrained (8%) and poolside (0%) conditions (both, P < 0.001). Airway management failure was similar among conditions for the cuffed oropharyngeal airway (poolside, 10%; free-floating, 15%; restrained, 15%), laryngeal mask airway (poolside, 0%; free-floating, 3%; restrained, 0%), and intubating laryngeal mask airway (poolside, 5%; free-floating, 5%; restrained, 10%). Airway management failure for the laryngoscope-guided tracheal intubation was usually caused by failed insertion (> 90%), and for the cuffed oropharyngeal airway, laryngeal mask airway, and intubating laryngeal mask airway, it was always a result of inadequate placement. CONCLUSION: The emphasis placed on the use of restraints for conventional tracheal intubation in microgravity is appropriate. Extratracheal airway devices may be useful when restraints cannot be applied or intubation is difficult.     

The LMA Fastrach™ facilitates fibreoptic intubation in oral cancer patients

PURPOSE: To compare ease of endotracheal intubation with the Intubating Laryngeal Mask Airway (ILMA) tracheal tube (TT; for LMA-Fastrach) and regular PVC TT (Portex) for nasotracheal fibreoptic intubation in oral cancer patients with a difficult airway. METHODS: 40 patients of physical status ASA I-II with a history of previous oral cancer surgery and/or postoperative radiotherapy scheduled for oral cancer surgery were randomly allocated by sealed envelopes to undergo tracheal intubation with either the ILMA TT or a standard TT. Ease of nasal passage of the TT and ease of tracheal intubation over the fibrescope was assessed. Peak airway pressures were assessed intraoperatively and postoperatively for 12 hr. RESULTS: The use of the ILMA TT increased the ease of nasotracheal intubation by increasing the percentage of successful tube placements at the first attempt (80%) in comparison with standard TT (35%); (P < 0.05). Peak airway pressures were found to remain low with the ILMA TT. None of the patients experienced any airway related complications. CONCLUSIONS: Use of a soft, flexible, nonkinking ILMA TT with a tapered tip design facilitates passage into the trachea over a fibreoptic bronchoscope and allows maintenance of lower airway pressures. The ILMA TT may be a useful adjunct for management of the difficult airway in oral cancer surgery.