Management choices for the difficult airway by anesthesiologists in Canada

Tracheal intubation in patients at risk for cervical spinal cord injury: A systematic review

BACKGROUND

Tracheal intubation in patients at risk for secondary spinal cord injury is potentially difficult and risky.

OBJECTIVES

To compare tracheal intubation techniques in adult patients at risk for secondary cervical spinal cord injury undergoing surgery. Primary outcome was first-attempt failure rate. Secondary outcomes were time to successful intubation and procedure complications.

DESIGN

Systematic review and meta-analysis of randomized controlled trials (RCTs) with trial sequential analysis (TSA).

DATA SOURCES

Databases searched up to July 2019.

ELIGIBILITY

Randomized controlled trials comparing different intubation techniques.

RESULTS

We included 18 trials enrolling 1972 patients. Four studies used the "awake" approach, but no study compared awake versus non-awake techniques. In remaining 14 RCTs, intubation was performed under general anesthesia. First-attempt failure rate was similar when comparing direct laryngoscopy or fiberoptic bronchoscopy versus other techniques. A better first-attempt failure rate was found with videolaryngoscopy and when pooling all the fiberoptic techniques together. All these results appeared not significant at TSA, suggesting inconclusive evidence. Intubating lighted stylet allowed faster intubation. Postoperative neurological complications were 0.34% (no significant difference among techniques). No life-threatening adverse event was reported; mild local complications were common (19.5%). The certainty of evidence was low to very low mainly due to high imprecision and indirectness.

CONCLUSIONS

Videolaryngoscopy and fiberoptic-assisted techniques might be associated with higher first-attempt failure rate over controls. However, low to very low certainty of evidence does not allow firm conclusions on the best tracheal intubation in patients at risk for cervical spinal cord injury.

Survey of Current Difficult Airway Management Practice

BACKGROUND

Even for the most experienced anesthesiologists "can't ventilate can't intubate" scenario in difficult airway management is challenging, and although rare it is life-threatening.

AIM

The aim of this survey was to analyse the current practice of difficult airway management at our University teaching hospital.

MATERIAL AND METHODS

A ten-question-survey was conducted in the Tertiary University Teaching Hospital "Mother Theresa", Clinic for Anesthesia, Reanimation and Intensive Care. The survey included demographic data, experience in training anaesthesia, practice in management of anticipated and non-anticipated difficult airway scenario, preferable equipment and knowledge of guidelines and protocols. Responses were noted, evaluated and analysed with the SPSS statistical program.

RESULTS

The overall response rate was very good; 94.5% answered the survey. During the assessment of the level of comfort with diverse airway equipment, there was diversity of answers due the experience of anaesthesia training, although the most frequent technique among all responders for anticipated difficult intubation was video laryngoscopy (48%). As for non-anticipated difficult intubation when conventional techniques failed to secure the airway most of the responders answered that they used supra-gothic airway device - laryngeal mask (38%) as a rescue measure.

CONCLUSION

Airway assessment, adequate training, experience, and availability of essential equipment are the pillars of successful airway management.

Fibreoptic intubation in airway management: a review article

Since the first use of the flexible fibreoptic bronchoscope, a plethora of new airway equipment has become available. It is essential for clinicians to understand the role and limitations of the available equipment to make appropriate choices. The recent 4th National Audit Project conducted in the United Kingdom found that poor judgement with inappropriate choice of equipment was a contributory factor in airway morbidity and mortality. Given the many modern airway adjuncts that are available, we aimed to define the role of flexible fibreoptic intubation in decision-making and management of anticipated and unanticipated difficult airways. We also reviewed the recent literature regarding the role of flexible fibreoptic intubation in specific patient groups who may present with difficult intubation, and concluded that the flexible fibrescope maintains its important role in difficult airway management.

Management of the airway in maxillofacial surgery: part 1

In part 1 of this review of management of the airway in maxillofacial surgery we discuss preoperative assessment of the airway, and the practical means to deal with difficulties. We review the evidence for videolaryngoscopy and flexible indirect laryngoscopy, together with surgical access to the airway including tracheostomy, cricothyroidotomy, and submental intubation.

Anesthetic considerations for patients with acute cervical spinal cord injury

Anesthesiologists work to prevent or minimize secondary injury of the nervous system and improve the outcome of medical procedures. To this end, anesthesiologists must have a thorough understanding of pathophysiology and optimize their skills and equipment to make an anesthesia plan. Anesthesiologists should conduct careful physical examinations of patients and consider neuroprotection at preoperative interviews, consider cervical spinal cord movement and compression during airway management, and suggest awake fiberoptic bronchoscope intubation for stable patients and direct laryngoscopy with manual in-line immobilization in emergency situations. During induction, anesthesiologists should avoid hypotension and depolarizing muscle relaxants. Mean artery pressure should be maintained within 85-90 mmHg (1 mmHg = 0.133 kPa; vasoactive drug selection and fluid management). Normal arterial carbon dioxide pressure and normal blood glucose levels should be maintained. Intraoperative neurophysiological monitoring is a useful option. Anesthesiologists should be attentive to postoperative respiratory insufficiency (carefully considering postoperative extubation), thrombus, and infection. In conclusion, anesthesiologists should carefully plan the treatment of patients with acute cervical spinal cord injuries to protect the nervous system and improve patient outcome.

Device and Medication Preferences of Canadian Physicians for Emergent Endotracheal Intubation in Critically Ill Patients

OBJECTIVES

Various medications and devices are available for facilitation of emergent endotracheal intubations (EETIs). The objective of this study was to survey which medications and devices are being utilized for intubation by Canadian physicians.

METHODS

A clinical scenario-based survey was developed to determine which medications physicians would administer to facilitate EETI, their first choice of intubation device, and backup strategy should their first choice fail. The survey was distributed to Canadian emergency medicine (EM) and intensive care unit (ICU) physicians using web-based and postal methods. Physicians were asked questions based on three scenarios (trauma; pneumonia; heart failure) and responded using a 5-point scale ranging from "always" to "never" to capture usual practice.

RESULTS

The survey response rate was 50.2% (882/1,758). Most physicians indicated a Macintosh blade with direct laryngoscopy would "always/often" be their first choice of intubation device in the three scenarios (mean 85% [79%-89%]) followed by video laryngoscopy (mean 37% [30%-49%]). The most common backup device chosen was an extraglottic device (mean 59% [56%-60%]). The medications most physicians would "always/often" administer were fentanyl (mean 45% [42%-51%]) and etomidate (mean 38% [25%-50%]). EM physicians were more likely than ICU physicians to paralyze patients for EETI (adjusted odds ratio 3.40; 95% CI 2.90-4.00).

CONCLUSIONS

Most EM and ICU physicians utilize direct laryngoscopy with a Macintosh blade as a primary device for EETI and an extraglottic device as a backup strategy. This survey highlights variation in Canadian practice patterns for some aspects of intubation in critically ill patients.

Resuscitation Prior to Emergency Endotracheal Intubation: Results of a National Survey

Introduction

Respiratory failure is a common problem in emergency medicine (EM) and critical care medicine (CCM). However, little is known about the resuscitation of critically ill patients prior to emergency endotracheal intubation (EETI). Our aim was to describe the resuscitation practices of EM and CCM physicians prior to EETI.

Methods

A cross-sectional survey was developed and tested for content validity and retest reliability by members of the Canadian Critical Care Trials Group. The questionnaire was distributed to all EM and CCM physician members of three national organizations. Using three clinical scenarios (trauma, pneumonia, congestive heart failure), we assessed physician preferences for use and types of fluid and vasopressor medication in pre-EETI resuscitation of critically ill patients.

Results

In total, 1,758 physicians were surveyed (response rate 50.2%, 882/1,758). Overall, physicians would perform pre-EETI resuscitation using either fluids or vasopressors in 54% (1,193/2,203) of cases. Most physicians would “always/often” administer intravenous fluid pre-EETI in the three clinical scenarios (81%, 1,484/1,830). Crystalloids were the most common fluid physicians would “always/often” administer in congestive heart failure (EM 43%; CCM 44%), pneumonia (EM 97%; CCM 95%) and trauma (EM 96%; CCM 96%). Pre-EETI resuscitation using vasopressors was uncommon (4.9%). Training in CCM was associated with performing pre-EETI resuscitation (odds ratio, 2.20; 95% CI, [1.44–3.36], p<0.001).

Conclusion

Pre-EETI resuscitation is common among Canadian EM and CCM physicians. Most physicians use crystalloids pre-EETI as a resuscitation fluid, while few would give vasopressors. Physicians with CCM training were more likely to perform pre-EETI resuscitation.

Current practice of difficult airway management: A survey

BACKGROUND AND AIMS

Difficult airway (DA) management depends on both training and actual usage of the various approaches in the event of difficulty. The aim of the study was to assess how well the anaesthesiologists are equipped to deal with DA situations. The current practice preference of DA management was also assessed.

METHODS

A questionnaire was distributed in a continuing medical education (CME) programme dedicated to DA and responses were noted and analysed, using Statistical Package for Social Sciences (SPSS) version 18.

RESULTS

The response rate was 73%. Airway assessment was performed by majority. Sixty eight percent consultants and 47% residents were well aware of the American Society of Anesthesiologists' DA algorithm. 67% consultants and 65% residents attended at least one CME on DA in the previous 5 years. There was an overall deficiency of video laryngoscopes, retrograde intubation and cricothyrotomy sets. Most of the respondents were comfortable in using supraglottic airway devices (SGADs). In anticipated DA, the preferred choice of management for junior doctors was attempting conventional method once and awake fibreoptic bronchoscopy (FOB) for the experienced. In unanticipated DA, most of the residents and consultants opted for SGAD. Extubation strategy was similar for both. Thirty four percent of respondents experienced a 'cannot intubate-cannot ventilate' situation at least once.

CONCLUSION

Our survey showed that most respondents performed routine pre-operative airway assessment. A good armamentarium of airway gadgets should be made available in hospitals. Further training in techniques like video laryngoscopy, FOB or cricothyrotomy are essential.

An economical model for mastering the art of intubation with different video laryngoscopes

Video laryngoscope (VL) provides excellent laryngeal exposure in patients when anaesthesiologists encounter difficulty with direct laryngoscopy. Videolaryngoscopy, like flexible fibreoptic laryngoscopy demands a certain level of training by practitioners to become dexterous at successful intubation with a given instrument. Due to their cost factors, VLs are not easily available for training purposes to all the students, paramedics and emergency medical services providers in developing countries. We tried to develop a cost-effective instrument, which can work analogous to various available VLs. An inexpensive and easily available instrument was used to create an Airtraq Model for VL guided intubation training on manikin. Using this technique, successful intubation of manikin could be achieved. The Airtraq Model mimics the Airtraq Avant^® and may be used for VL guided intubation training for students as well as paramedics, and decrease the time and shorten the learning curve for Airtraq^® as well as various other VLs.

Recent trends in airway management: we are not ready to give up fiberoptic endoscopy

The purpose of this correspondence is to discuss recent findings related to current trends in airway management and to discuss the utilization rates of video laryngoscopes versus traditional techniques in USA, UK, and Canada. To highlight the increased use of video laryngoscopes in difficult airway situations, data on the use of alternative airway devices at our institution collected from 2008 to 2010 are presented alongside the results of previously published surveys collected from 2002 to 2013.

An Audit of Fibreoptic Intubation Training Opportunities in a UK Teaching Hospital

Airway management is the foundation upon which anaesthesia is built, and fibreoptic intubation (FOI) is a key facet of this skill. Despite this, many trainee anaesthetists in the UK have been unable to perform sufficient FOIs to gain competence. We aimed to establish the incidence of FOI in adult patients, in a UK teaching hospital, in order to determine what FOI training opportunities actually exist. During the study period (from October 1st, 2008, to September 30th, 2009) an estimated 11 712 general anaesthetics were undertaken that necessitated tracheal intubation. In 141 of these cases FOIs were performed giving an incidence of FOI of 1.2% (95% confidence interval 1%–1.4%). Of these, 86 (61%) were in awake and 55 (39%) in anaesthetised patients. Only 16 (11%) of the FOIs were done solely for the purposes of training. We suggest that a greater number of FOIs should be undertaken to allow trainees to gain and consultants to maintain the FOI expertise necessary for the provision of safe anaesthesia.

The difficult airway with recommendations for management--part 2--the anticipated difficult airway

BACKGROUND

Appropriate planning is crucial to avoid morbidity and mortality when difficulty is anticipated with airway management. Many guidelines developed by national societies have focused on management of difficulty encountered in the unconscious patient; however, little guidance appears in the literature on how best to approach the patient with an anticipated difficult airway.

METHODS

To review this and other subjects, the Canadian Airway Focus Group (CAFG) was re-formed. With representation from anesthesiology, emergency medicine, and critical care, CAFG members were assigned topics for review. As literature reviews were completed, results were presented and discussed during teleconferences and two face-to-face meetings. When appropriate, evidence- or consensus-based recommendations were made, and levels of evidence were assigned.

PRINCIPAL FINDINGS

Previously published predictors of difficult direct laryngoscopy are widely known. More recent studies report predictors of difficult face mask ventilation, video laryngoscopy, use of a supraglottic device, and cricothyrotomy. All are important facets of a complete airway evaluation and must be considered when difficulty is anticipated with airway management. Many studies now document the increasing patient morbidity that occurs with multiple attempts at tracheal intubation. Therefore, when difficulty is anticipated, tracheal intubation after induction of general anesthesia should be considered only when success with the chosen device(s) can be predicted in a maximum of three attempts. Concomitant predicted difficulty using oxygenation by face mask or supraglottic device ventilation as a fallback makes an awake approach advisable. Contextual issues, such as patient cooperation, availability of additional skilled help, and the clinician's experience, must also be considered in deciding the appropriate strategy.

CONCLUSIONS

With an appropriate airway evaluation and consideration of relevant contextual issues, a rational decision can be made on whether an awake approach to tracheal intubation will maximize patient safety or if airway management can safely proceed after induction of general anesthesia. With predicted difficulty, close attention should be paid to details of implementing the chosen approach. This should include having a plan in case of the failure of tracheal intubation or patient oxygenation.

Drug shortages in Canadian anesthesia: a national survey

BACKGROUND

Canadian physicians are faced with an increasing frequency of drug shortages. We hypothesized that drug shortages have a clinical impact on anesthesia care in Canada.

METHODS

We conducted a self-administered survey of anesthesiologists in Canada using the membership list of the Canadian Anesthesiologists' Society. For survey development, we identified key domains, including types of drug shortages, impact on the ability of anesthesia practitioners to provide general anesthesia care, and impact on patient outcomes. We undertook assessments of face validity, clinical sensibility, and content validity. Respondents were surveyed from January-April 2012.

RESULTS

Completed valid questionnaires were submitted by 1,187 respondents (61.4%), and 779 (65.7%) of respondents described a shortage of one or more anesthesia or critical care drugs. Changes in anesthesia practice resulting from drug shortages were common; 586 (49%) respondents thought they had given an inferior anesthetic, and 361 (30%) reported administering medications with which they were unfamiliar. Respondents also reported that drug shortages were, at times, responsible for changes in the conduct of patient care, with 28 (2.4%) noting cancellation or postponement of surgery and 92 (7.8%) witnessing a drug error. One hundred sixty-five (13.9%) respondents regarded drug shortages as having prolonged recovery from anesthesia, and 124 (10.5%) viewed drug shortages as resulting in an increased number of postoperative complications, such as postoperative nausea and vomiting.

INTERPRETATION

Drug shortages are common in anesthetic practice in Canada. This state of affairs may have a negative effect on how anesthesiologists practice anesthesia and may be associated with adverse patient outcomes.

Use of intubation introducers through a supraglottic airway to facilitate tracheal intubation: a brief review

PURPOSE

This article is a narrative review regarding the usage and effectiveness of introducers or catheters to facilitate tracheal intubation through a supraglottic airway (SGA) as an alternative intubation technique in normal and difficult airway management.

SOURCES

Relevant articles were obtained through Medline (1948-July 2011). The articles were subsequently cross-referenced for additional literature, and only articles published in English were included.

PRINCIPAL FINDINGS

In this review, we consider 32 reports using the LMA Classic™, LMA Unique™, LMA ProSeal™, LMA Supreme™, AuraOnce™, and i-gel™ as SGA conduits for intubation. In 13 articles, the use of an Aintree Intubation Catheter was described as an intubation introducer and resulted in high success rates in both elective and emergent situations. Eight studies used a guidewire exchange catheter technique. Although blind intubation using a guidewire resulted in a high failure rate, these studies found that using a bronchoscope improved successful intubation. Ten studies showed that insertion of a gum elastic bougie with a bronchoscope as an intubation introducer has high success rates compared with blind bougie insertion. One article described the use of a small endotracheal tube as an intermediary for tracheal intubation.

CONCLUSIONS

In failed intubation scenarios, supraglottic airways, such as the LMA Classic™ or LMA ProSeal™ can serve as a conduit for tracheal intubation. A number of techniques using introducers or catheters can facilitate the insertion of an adequately sized endotracheal tube, particularly guided by a bronchoscope. Usage of introducers or catheters through a supraglottic airway may be a useful alternative intubation technique in difficult airway management.

Education in airway management

In airway management, poor judgment, education and training are leading causes of patient morbidity and mortality. The traditional model of medical education, which relies on experiential learning in the clinical environment, is inconsistent and often inadequate. Curriculum change is underway in many medical organisations in an effort to correct these problems, and airway management is likely to be explicitly addressed as a clinical fundamental within any new anaesthetic curriculum. Competency-based medical education with regular assessment of clinical ability is likely to be introduced for all anaesthetists engaged in airway management. Essential clinical competencies need to be defined and improvements in training techniques can be expected based on medical education research. Practitioners need to understand their equipment and diversify their airway skills to cope with a variety of clinical presentations. Expertise stems from deliberate practice and a desire constantly to improve performance with a career-long commitment to education.

A comparison of four techniques of emergency transcricoid oxygenation in a manikin

Cricothyroidotomy is the final rescue maneuver in difficult airway management. We compared 4 techniques of oxygenation via the cricothyroid membrane in a manikin. The techniques were wire guided, trocar, cannula with jet ventilation, and blade technique (scalpel with endotracheal tube). In the wire-guided group, the time taken to ventilation was slower on all attempts, and there were no successful attempts in <40 seconds. There were no differences between the other groups at any time. Time to ventilation improved with repetition in all groups. Skills were retained at 1 month.

The Fastrach Intubating Laryngeal Mask Airway: an overview and update

PURPOSE

To provide an evidence-based overview and update on the use of the Fastrach Intubating Laryngeal Mask Airway (FT-LMA) when used within operative and non-operative settings.

PRINCIPAL FINDINGS

The FT-LMA is available in three sizes to provide ventilation and the ability to pass an endotracheal tube (ETT) into the trachea blindly, semi-blindly, or with indirect visualization for patients over 30 kg. The Chandy maneuver is recommended routinely; the first maneuver optimizes ventilation, and the second maneuver increases success at endotracheal intubation (ETI). The manufacturer's reinforced tube or a pre-warmed or reversed standard ETT may be utilized. Insertion and ventilation are successful in almost all patients. Blind ETI is highly successful; adjuncts are generally not necessary. The FT-LMA has a proven role in the airway management of anticipated difficult operating room (OR) intubations, unanticipated OR intubations, cervical spine injuries, and limited airway access situations. Literature in the pre-hospital and emergency department settings is limited but favourable. The FT-LMA has compared favourably with fibreoptic intubation, the LMA-Classic, the laryngeal tube, and the CobraPLA. Initially, the more expensive LMA CTrach appeared to be more successful, but overall it is not. The FT-LMA airway seal pressures are excellent; serious complications are uncommon, and the FT-LMA figures prominently in most difficult airway guidelines.

CONCLUSIONS

The FT-LMA has proven to be a useful difficult airway device both within and outside of the operating room. Effective ventilation is established in nearly all cases, and blind ETI is possible in the vast majority of cases if the optimal techniques described are used. Serious complications are uncommon.

Practice Patterns for Predicted Difficult Airway Management and access to Airway Equipment by Anaesthetists in Queensland, Australia

A postal survey was conducted to investigate difficult airway management, training and equipment availability among Fellows of the Australian and New Zealand College of Anaesthetists in Queensland. The survey aimed to determine practise patterns for predicted difficult airways and investigate equipment availability.

Participants were asked to nominate an induction method, intubation method and airway adjunct for each of the five difficult airway scenarios. The cases consisted of one elective and four emergency scenarios. Availability of difficult airway devices in their institution was also assessed, as well as demographics of practice and airway-related maintenance of professional standards participation.

There were 454 surveys distributed and 250 returned (response rate 55%). Direct laryngoscopy and flexible fibreoptic intubation were the most commonly selected techniques for all five cases. Difficult intubation trolleys were available to 98% of responders. Certain types of equipment (such as fibreoptic bronchoscopes and cricothyroidotomy kits) were available less frequently in private institutions. We recommend a standardisation of difficult airway management equipment and an on-going training program to provide support for anaesthetists in all locations.

Tracheal intubation practice and maintaining skill competency: survey of pediatric emergency department medical directors

PURPOSE

One of the most critical resuscitation skills in pediatric emergency medicine is establishing and maintaining a patent airway. This often requires tracheal intubation (TI). The purpose of this survey study was to determine the practice of TI in pediatric emergency departments (PEDs) and the methods used by PED medical directors to maintain TI competency among PED physicians.

METHODS

This is an observational survey study. Medical directors of PEDs were surveyed through e-mail (http://web-online-surveys.com). There were 20 survey questions: 4 yes/no and 16 multiple choice.

RESULTS

Of the 108 PED medical directors who were surveyed, 61 (57%) completed the questionnaire. The mean number of TI per PED for 1 year was 63.7; SD, 79.3; median, 37; range, 3 to 400. The mean percentage of TI that were rapid sequence intubations was 76%; SD, 19.8%; median, 83%; range, 30% to 100%. The physician types most commonly performing TI on nontrauma versus trauma patients were as follows: pediatric emergency medicine, 50 (82%) versus 43 (70%); emergency medicine, 4 (7%) versus 4 (7%); and anesthesiology, 1 (2%) versus 4 (7%). The physician types most commonly consulted for difficult airway patients were: anesthesiology, 40 (66%); and pediatric critical care, 14 (23%). Alternative or rescue airway equipment/procedures available to PED were as follows: laryngeal mask airway (LMA), 50 (90%); needle cricothyroidotomy, 47 (77%); fiberoptic scope, 34 (56%); and tracheal tube introducer, 22 (36%). There were 38 (62%) PED medical directors who judged the number of TI opportunities to be inadequate to maintain TI competency among their physicians. The following activities reported as required for remedial training or to maintain TI competency were: pediatric advanced life support/advanced pediatric life support courses, 42 (69%); simulation training, 29 (48%); perform TI under the supervision of an anesthesiologist, 23 (38%); advance airway course, 21 (34%); and/or none, 1 (2%).

CONCLUSIONS

Most PED TI for both nontrauma and trauma patients were performed by PED physicians. Most of these were rapid sequence intubations. The number of TI per PED had a large range. Most PED medical directors judged this number to be inadequate to maintain TI competency. Didactic activities to maintain TI skills were most common, but many other activities were used.

Cervical spine motion during tracheal intubation with manual in-line stabilization: direct laryngoscopy versus GlideScope videolaryngoscopy

BACKGROUND

The optimal tracheal intubation technique for patients with potential cervical (C) spine injury remains controversial. Using continuous cinefluoroscopy, we conducted a prospective study comparing C-spine movement during intubation using direct laryngoscopy (DL) or GlideScope videolaryngoscopy (GVL), with uninterrupted manual in-line stabilization of the head by an assistant.

METHODS

Twenty patients without C-spine pathology were studied. After induction of general anesthesia with neuromuscular blockade, both DL and GVL were performed on every patient in random order. Cinefluoroscopic images of C-spine movement during GVL and DL were acquired and divided into four stages: a baseline image before airway manipulation, glottic visualization, insertion of the endotracheal tube into the glottis, and tracheal intubation. Peak segmental motion from the occiput to C5 was measured offline for each patient and each stage, averages were calculated, and movements induced by each instrument were compared using a two-way ANOVA. Also studied were the proportion of patients with occiput-C1 rotation exceeding 10, 15, or 20 degrees, and the quality of glottic visualization.

RESULTS

No significant difference was found between DL and GVL regarding average segmental spine movement at any level (P values between 0.22 and 0.70). During both techniques, motion was mainly an extension concentrated in the rostral C-spine and occurred predominantly during glottic visualization. The proportion of patients with occiput-C1 extension of more than 10, 15, or 20 degrees was not significantly different. Glottic visualization was significantly better with GVL compared with DL.

CONCLUSION

During intubation under general anesthesia with neuromuscular blockade and manual in-line stabilization, the use of GVL produced better glottic visualization, but did not significantly decrease movement of the nonpathologic C-spine when compared with DL.

Challenging airways in deep neck space infections

Skilful airway management is critical in deep neck space infections. Although relatively uncommon, this spectrum of disease presents a clinical challenge for otolaryngologists and anesthetists. There is currently no universal agreement on the ideal method of airway control for these patients because this depends on various factors including available local expertise and equipment. We review the literature and discuss the available options of airway management in these head and neck emergencies. Special consideration is given to awake fiberoptic intubation and tracheotomy under local anesthesia. Relevant anatomy, route of spread and microbiology of deep neck space infections are also briefly discussed.

Management of the Airway in Patients Undergoing Cervical Spine Surgery

The perioperative management of the airway in patients with cervical spine disease requires careful consideration. In an observational prospective cohort study, we assessed the preoperative factors that may have influenced the anesthesiologists' choice for the technique of intubation and the incidence of postoperative airway complications. We recorded information from 327 patients: mean (+/-SD) age 51+/-15 year, 138 females and 189 males, for anterior surgical approach (n=195) and posterior (n=132). The technique of intubation used was awake fiberoptic bronchoscopy (FOB) in 39% (n=128), asleep FOB 32% (n=103), asleep laryngoscopy 22% (n=72), and other asleep 7% (n=24). Awake FOB was predominately chosen for intubating patients with myelopathy (45%), unstable/fractured spine (73%), and spinal stenosis (55%) but patients with radiculopathy had more asleep FOB (49%) (P<0.001). There was no association between method of intubation and postoperative airway complications. Acute postoperative airway obstruction occurred in 4 (1.2%) patients requiring reintubation. The technique of management of the airway for cervical spine surgery varied considerably among the anesthesiologists, although the choice was not associated with postoperative airway complications.

The laryngeal mask airway prevents supraglottic leak during ventilation through an uncuffed cricothyroidotomy

PURPOSE

A 'cannot intubate-cannot ventilate' situation requires emergency insertion of an infraglottic surgical airway. We present a case of postoperative macroglossia requiring emergency insertion of an uncuffed percutaneous cricothyroidotomy tube. The supraglottic leak was eliminated by the insertion of a laryngeal mask airway with an occluded 15-mm connector.

CLINICAL FEATURES

A 49-yr-old man underwent clipping of a left posterior inferior cerebellar artery aneurysm and his tracheal tube was removed postoperatively. Two hours later, he became dyspneic and developed significant macroglossia. After application of topical anesthesia, direct laryngoscopy, oral fibreoptic bronchoscopy and laryngeal mask insertion were unsuccessful. The patient became progressively hypoxemic, pulseless electrical activity ensued, and cardiopulmonary resuscitation was initiated. An uncuffed percutaneous cricothyroidotomy tube was inserted. Oxygenation and hemodynamics were restored. As the cricothyroidotomy tube was uncuffed, there was a large supraglottic leak with manual ventilation. A laryngeal mask airway was inserted and the cuff was inflated. The 15-mm connector was occluded by a piece of tape. Subsequently, there was no further supraglottic leak with manual ventilation. He was taken to operating room and a surgical tracheotomy was performed.

CONCLUSION

In a patient with postoperative macroglossia in a 'cannot intubate-cannot ventilate' situation, effective oxygenation was restored by insertion of an uncuffed cricothyroidotomy, but ventilation was affected by a substantial supraglottic leak. A new strategy using an inflated laryngeal mask airway with an occluded connector was utilized to successfully terminate the supraglottic leak, thereby restoring effective lung ventilation.

Management of unexpected difficult airway at a teaching institution over a 7-year period

STUDY OBJECTIVE

To review an anesthesiology department's experience with managing unexpected difficult airways over a 7-year time span.

DESIGN

Retrospective review of unexpected difficult airway reporting forms.

SETTING

A tertiary care teaching hospital.

PATIENTS

447 patients who had an unanticipated difficult airway and had a difficult airway form filled out by their anesthesiologist.

MEASUREMENTS

Retrospective identification of pertinent physical features associated with difficult intubation was noted. The techniques chosen, their success, and the frequency with which the different advanced airway techniques were chosen was reviewed.

MAIN RESULTS

An anterior larynx was the most common anatomical feature associated with difficult laryngoscopy. When a laryngeal mask airway was placed in our patients, ventilation was possible in all patients. Intubation was successfully "blindly" achieved (ie, without the use of a fiberoptic bronchoscope) through the laryngeal mask airway in 52% of these patients. Fiberoptic intubation was unsuccessful in intubating approximately 10% of patients. The Bullard laryngoscope was the most common advanced airway technique chosen at our institution.

CONCLUSION

Mastery with a number of advanced airway techniques should be sought, as multiple modalities may be needed when faced with managing an unexpectedly difficult airway. Formal written communication to the patient of an unexpected difficult airway encounter may allow future anesthesiologists to formulate an appropriate plan for patient care.

Pre-anesthetic evaluation can play a crucial role in the determination of airway management in a child with oropharyngeal tumor

We experienced a case of a huge hemangioma occupying the oropharyngeal space in an 11-year-old child. Although urgent surgical tracheostomy under local anesthesia was suggested initially, medical interview and findings of computerized tomography and fiberoptic laryngoscopy revealed that the airway of the patient was relatively stable when she was in the semi-left decubitus position. General anesthetic induction would have had potential risks of airway obstruction. Thus, after placing the patient in the semi-left decubutus position, we chose semi-awake induction to secure the airway. With a small dose of fentanyl, we accomplished orotracheal intubation. In this report, we discuss the importance of referring to an airway management algorithm when encountering a difficult airway.

Fibreoptic intubation skills among anaesthetists in New Zealand

The aim of this study was to investigate methods of practice, assess skill level, and evaluate attitudes towards fibreoptic intubation in the anaesthetic community of New Zealand. A postal survey questionnaire was sent to all vocationally registered anaesthetists in New Zealand and to all New Zealand anaesthetic trainees registered with the Australian and New Zealand College of Anaesthetists. There were 611 survey questionnaires posted and 386 (63%) respondents. Almost all respondents (98% of specialists, 100% of trainees) had access to fibreoptic equipment in public and 92% of respondents performed fibreoptic intubation. The median number of fibreoptic intubations performed per year was 3 for consultants and 4 for trainees. Respondents were either self taught or colleague taught (82%). Most learnt the technique on patients (92%). There were 14% who considered themselves experienced, 30% competent, 34% adequate and 20% novice. Skills were maintained by clinical patient mix in 73%. Fibreoptic intubation was considered a skill required by all anaesthetists in 87%, and 66% considered it the gold standard for expected difficult airways. Lack of clinical cases requiring the skill and lack of practice were identified as the primary barriers to skill development. Consultants had greater opportunity to learn fibreoptic intubation skills during daily practice than trainees. Only 18% of trainees had a formal airway management program available to them at their place of work. There appears to be a need to increase available opportunities to perform fibreoptic intubation to enable maintenance and improvement of fibreoptic skills in our community. A formalized program of teaching fibreoptic intubation may offer greater opportunity for learning and skill development.

Anterior cervical screw extrusion leading to acute upper airway obstruction: case report

STUDY DESIGN

Case report of late postoperative complication.

SUMMARY OF BACKGROUND DATA

There have been a number of reports of migration and extrusion of cervical fusion instrumentation. The majority of such cases have a benign outcome. To our knowledge, cervical instrumentation extrusion resulting in prevertebral abscess and acute airway obstruction has not been reported.

METHODS

A 56-year-old man who had undergone a prior C3-C6 anterior cervical decompression and fusion presented to a hospital with dysphagia and acute airway obstruction requiring an emergency tracheostomy. His neck radiograph showed that a C6 screw was missing compared to prior films. Magnetic resonance imaging showed a large prevertebral abscess anterior to C2-C7 causing complete upper airway obstruction.

RESULTS

He underwent surgical drainage of the abscess and had a good neurologic recovery.

CONCLUSIONS

We report a case of acute upper airway obstruction from prevertebral abscess, likely secondary to a loosened anterior cervical screw penetrating the prevertebral soft tissue. In contrast to case reports in the literature involving instrumentation extrusion with a usually benign outcome, our case presented with a life-threatening condition.

Early clinical experience with a new videolaryngoscope (GlideScope) in 728 patients

PURPOSE

To evaluate a new videolaryngoscope and assess its ability to provide laryngeal exposure and facilitate intubation.

METHODS

Five centres, involving 133 operators and a total of 728 consecutive patients, participated in the evaluation of a new video-laryngoscope [GlideScope (GS)]. Many operators had limited or no previous GS experience. We collected information about patient demographics and airway characteristics, Cormack-Lehane (C/L) views and the ease of intubation using the GS. Failure was defined as abandonment of the technique.

RESULTS

Data from six patients were incomplete and were excluded. Excellent (C/L 1) or good (C/L 2) laryngeal exposure was obtained in 92% and 7% of patients respectively. In all 133 patients in whom both GS and direct laryngoscopy (DL) were performed, GS resulted in a comparable or superior view. Among the 35 patients with C/L grade 3 or 4 views by DL, the view improved to a C/L 1 view in 24 and a C/L 2 view in three patients. Intubation with the GS was successful in 96.3% of patients. The majority of the failures occurred despite a good or excellent glottic view.

CONCLUSIONS

GS laryngoscopy consistently yielded a comparable or superior glottic view compared with DL despite the limited or lack of prior experience with the device. Successful intubation was generally achieved even when DL was predicted to be moderately or considerably difficult. GS was abandoned in 3.7% of patients. This may reflect the lack of a formal protocol defining failure, limited prior experience or difficulty manipulating the endotracheal tube while viewing a monitor.

Airway management after failure to intubate by direct laryngoscopy: outcomes in a large teaching hospital

PURPOSE

The purpose of this single-centre database review was to establish the incidence of failure to intubate by direct laryngoscopy, to measure morbidity and mortality associated with this event, and to examine the use and efficacy of alternative airway devices.

METHODS

Difficult intubation via direct laryngoscopy at Mayo Clinic Rochester is recorded in an electronic database using a functional classification: 0 = no difficulty; 1 = mild to moderate difficulty; and 2 = severe difficulty often requiring a change in intubation technique. Using this database, the total number of intubations was determined for a selected review period and the incidence of failure to intubate by direct laryngoscopy was established. Abstraction of chart data allowed for determination of associated morbidity and mortality, success of alternative airway devices, and case cancellation rate.

RESULTS

During the period from August 1, 2001 through December 31, 2002, 37,482 patients underwent general anesthesia with attempted direct laryngoscopy. One hundred sixty-one patients (0.43%) could not be intubated by direct laryngoscopy alone. Morbidity associated with difficult intubation included soft tissue/dental damage (n = 8), intraoperative cardiac arrest (n = 1), and possible aspiration (n = 1). Three patients required intensive care unit admission. There was no associated mortality. The most commonly used alternative airway device was the flexible fibreoptic scope. Five case cancellations resulted from failure to intubate with alternative devices.

CONCLUSION

The rate of unexpected failure to intubate by direct laryngoscopy is essentially unchanged from earlier studies. While morbidity was low, continued education and early use of alternative difficult airway devices may further limit complications associated with this event.