Integrating the Airway Lead structure into a large healthcare system to appraise the landscape of airway management resources

To the Editor, We report a case involving a patient with an unanticipated difficult airway in whom tracheal intubation was achieved uneventfully by advancing a bronchoscope and a tracheal tube introducer through a LMA Supreme. The patient’s written consent was obtained for this publication. A 70 kg, 52-yr-old woman was scheduled for nephrolithotomy. She had an adequate mouth opening, a normal thyromental distance, and a Mallampati class 3 airway. Anesthesia was induced with midazolam, fentanyl, propofol, and atracurium iv. Adequate mask ventilation was achieved. Direct laryngoscopy with a Macintosh #3 blade showed a Cormack-Lehane Grade 3 laryngeal view and tracheal intubation failed in two attempts. After further mask ventilation, oral bronchoscopic (5.0 mm outer diameter [OD]) intubation was attempted but failed due to poor visualization from blood and secretions. The SPO2 decreased to 90%. A size 4 LMA Supreme (LMA International, Singapore) was inserted with a satisfactory capnographic waveform and SPO2 returned to 100%. A decision was then made to intubate the patient’s trachea via the LMA Supreme. A pediatric bronchoscope (Olympus BF XP60, 2.8 mm OD) operated by an anesthesiologist and a solid tracheal tube introducer with a coude tip (5 mm OD, Well Lead Medical, China) operated by a second anesthesiologist were advanced through the airway lumen of the LMA Supreme into the pharynx (Figure). The tracheal tube introducer was advanced under bronchoscopic guidance through the glottis into the trachea and positioned 3 cm above the carina. The bronchoscope and LMA Supreme were then removed while keeping the tracheal tube introducer in position. A 7.0 mm internal diameter (ID) tracheal tube was railroaded over the tracheal tube introducer and into the trachea, and positioning of the tracheal tube was confirmed by capnography. Ten minutes after the completion of surgery, the patient was awakened and the tracheal tube was removed. The patient’s recovery was uneventful. After failed attempts at tracheal intubation, a supraglottic airway may be inserted for lung ventilation while awaiting alternative airway equipment. In lieu of removing the supraglottic airway to attempt alternative intubation techniques, it can be kept in situ as a conduit for tracheal intubation. Ventilation is not interrupted and secretions and blood are kept posterior to the supraglottic airway allowing a clear path to the larynx. The LMA Supreme is a single-use variant of the LMA Proseal. Its curved shaft consists of a double lumen, i.e., a central lumen for gastric access within an airway lumen for respiratory tract access. Like the LMA Classic, it is difficult to pass an adequately sized endotracheal tube (ETT) directly through the LMA Supreme due to the airway luminal diameter. There are four techniques to achieve tracheal intubation with an adequately sized ETT, through the use of introducers or catheters, via the LMA Supreme. The four techniques utilize a small ETT, an Aintree Intubating Catheter, a guidewire, or a tracheal tube introducer. With the first technique, a small ETT (up to 6.0 mm ID) is mounted over a bronchoscope and inserted into the trachea through the LMA Supreme. Subsequently, an airway exchange catheter is inserted via the ETT, which is later exchanged for a full-sized ETT. Q.-J. Chu, MD X.-P. Han, MD First Affiliated Hospital, Zhengzhou University, Zhengzhou, China

The objective was to evaluate patterns of pediatric coronavirus disease 2019 testing in a large health system throughout the pandemic, before and after school reopening. This was a cross-sectional time-series study of clinical virology results from children tested for severe acute respiratory syndrome coronavirus 2 in Southern Connecticut and areas of New York and Rhode Island. Data collected include demographics, hospital admission, changes in percent positive tests over time, detection intervals in persistently positive children and cycle threshold values. The setting was the Yale New Haven Health System has 6 hospitals at 4 Connecticut locations, 1 hospital in Rhode Island and ambulatory locations in Connecticut, Rhode Island and New York. Participants included twenty-three-thousand one-hundred thirty-seven children ≤ 18 years of age, tested for coronavirus disease 2019 at an ambulatory testing site, the emergency department or on an inpatient unit within the Yale New Haven Health System. Among all tests, 3.2% were positive. Older children consistently made up the larger portion of positive pediatric cases, regardless of community prevalence. Increased pediatric cases later in the pandemic when prevalence in adults was relatively low correlates with a higher number of tests performed in children and not with an increased positivity rate. No significant changes in trends of positivity were detected after the reopening of schools. Symptomatic and asymptomatic children had similar cycle threshold values regardless of age, and a subset of children demonstrated persistent viral detection, some for as long as 6 weeks. An increase in pediatric cases documented in the late summer was predominately due to increased access to testing for children. The percent positivity in children did not change in the first 3 weeks after school opened. A subset of children has detectable severe acute respiratory syndrome coronavirus 2 RNA in the upper respiratory tract for weeks after the initial infection.

The Airway Lead: opportunities to improve institutional and personal preparedness for airway management

Anesthesia-related causes contribute to a significant proportion of perioperative deaths, especially in low and middle-income countries (LMICs). There is evidence that complications related to failed airway management are a significant contributor to perioperative morbidity and mortality. While existing data have highlighted the magnitude of airway management complications in LMICs, there are inadequate data to understand their root causes. This study aimed to pilot an airway management capacity tool that evaluates airway management resources, provider practices, and experiences with difficult airways in an attempt to better understand potential contributing factors to airway management challenges. We developed a novel airway management capacity assessment tool through a nonsystematic review of existing literature on anesthesia and airway management in LMICs, internationally recognized difficult airway algorithms, minimum standards for equipment, the safe practice of anesthesia, and the essential medicines and health supplies list of Uganda. We distributed the survey tool during conferences and workshops, to anesthesia care providers from across the spectrum of surgical care facilities in Uganda. The data were analyzed using descriptive methods. Between May 2017 and May 2018, 89 of 93 surveys were returned (17% of anesthesia providers in the country) from all levels of health facilities that provide surgical services in Uganda. Equipment for routine airway management was available to all anesthesia providers surveyed, but with a limited range of sizes. Pediatric airway equipment was always available 54% of the time. There was limited availability of capnography (15%), video laryngoscopes (4%), cricothyroidotomy kits (6%), and fiber-optic bronchoscopes (7%). Twenty-one percent (18/87) of respondents reported experiencing a "can't intubate, can't ventilate" (CICV) scenario in the 12 months preceding the survey, while 63% (54/86) reported experiencing at least 1 CICV during their career. Eighty-five percent (74/87) of respondents reported witnessing a severe airway management complication during their career, with 21% (19/89) witnessing a death as a result of a CICV scenario. We have developed and implemented an airway management capacity tool that describes airway management practices in Uganda. Using this tool, we have identified significant gaps in access to airway management resources. Gaps identified by the survey, along with advocacy by the Association of Anesthesiologists of Uganda, in partnership with the Ugandan Ministry of Health, have led to some progress in closing these gaps. Expanding the availability of airway management resources further, providing more airway management training, and identifying opportunities to support skilled workforce expansion have the potential to improve perioperative safety in Uganda.

The purpose of this Continuing Professional Development module is to describe anatomic and physiologic challenges in obese patients, review their effects on oxygenation and airway management, and propose strategies for perioperative management. The combination of excess adipose tissue deposition, increased oxygen consumption, reduced lung volumes, and increased airway resistance in obese patients increases the risk of a difficult airway and rapid oxygen desaturation in the perioperative period. Preoxygenation can be optimized by a head-up or reverse Trendelenburg position, continuous positive airway pressure, and pressure support ventilation. Difficulties in bag and mask ventilation may occur. Laryngeal exposure during direct laryngoscopy is best achieved with the patient in the "ramped" position. Tracheal tube introducers or intubating stylets can assist tracheal intubation when suboptimal laryngeal views are obtained, and video laryngoscopy may help improve the glottic view and success of tracheal intubation. New generation double-lumen supraglottic airway devices provide higher leak pressures and may be safer in obese patients, and they can also provide a conduit for bronchoscopic intubation. In patients with anticipated difficult airways, preparations should be made for awake tracheal intubation. Intraoperatively, ventilatory strategies, such as recruitment maneuvers with positive end-expiratory pressure, may reduce atelectasis and improve oxygenation. Tracheal extubation in the head-up position and continuous positive airway pressure reduce postoperative hypoxemia. Following a difficult tracheal intubation, extubation over an airway exchange catheter should be considered. Rapid oxygen desaturation may occur in obese patients. Potential difficulties in airway management should be assessed and anticipated, and oxygenation, ventilation, and airway management strategies should be optimized perioperatively.

Michigan Medicine: The University of Michigan Head and Neck Anesthesiology and Advanced Airway Management Fellowship

Failed or difficult intubation is still a major cause of maternal morbidity and mortality. The management of the airway in the pregnant patient requires careful consideration of anatomical and physiological changes, training issues, and situational factors. Despite significant improvements in monitoring and airway equipment, and a reduction in anaesthetic-related maternal mortality, the incidence of failed intubation in the pregnant woman in many units has remained between 1/250 and 1/300. This may result from many factors such as the reduction of the number of caesarean deliveries performed under general anaesthesia which has resulted in limited opportunities to teach airway skills in obstetrics, the increased incidence of obesity, and the rise in maternal age and associated co-morbidities. Improved training and careful planning and performance of a general anaesthetic (i.e. reducing the risk of aspiration; optimum pre-oxygenation, patient positioning, and application of cricoid pressure; and availability of appropriate airway equipment) have the potential to reduce airway-related morbidity and mortality in the pregnant woman. Simple bedside tests such as Mallampati scoring, thyromental distance, neck movement, and ability to protrude the mandible may help to predict a potential difficult airway, particularly when used in combination. Management of a predicted difficult airway requires early referral to the anaesthetists, formulation of an airway management strategy, and involvement of the multidisciplinary team in decision-making. Fibreoptic equipment and skills should be readily available when required. Management of the unpredicted difficult airway should make maintenance of maternal and fetal oxygenation the primary goal. Decision-making during a failed intubation on whether to proceed or wake the patient should involve the obstetrician and ideally be planned in advance. The periods during extubation and recovery are high risk and require preparation and planning in advance.

Welcome to the era of universal airway management.

TRACHEAL stenosis is a rare but a life-threatening condition and is caused by congenital problems, postintubation injury, trauma, tracheal tumor, and compression of the trachea by tumor. Although accurate prevalence of this condition is unknown, an incidence of 4.9 cases per million per year is estimated for postintubation tracheal stenosis.1A stenosis commonly occurs at the cuff of the tube (intrathoracic trachea) or at the level of the tracheostomy stoma (extrathoracic trachea).Anesthesia of a patient with tracheal stenosis is challenging for anesthesiologists. Depending on the severity and location of the stenosis and the type of surgical procedure, there may be a variety of choices for perioperative airway management such as a facemask, laryngeal mask airway,2an tracheal intubation tube,3,4cardiopulmonary bypass,5and extracorporeal membrane oxygenation.6The American Society of Anesthesiologists practice guidelines for management of the difficult airway primarily focus airway problems caused at the extrathoracic airway and may not be helpful, particularly for managing patients with intrathoracic tracheal stenosis.7In this case scenario, we present a patient with severe intrathoracic tracheal stenosis, who required surgery for a lumbar fracture in the prone position. Various airway management strategies and the actual management used are discussed.A 38-yr-old obese man (height, 172 cm; weight, 95 kg; body mass index, 32 kg/m2) was scheduled to have a thoracolumbar laminectomy and fixation for a burst fracture of the first lumbar vertebra. Surgery was to be performed in the prone position. The operation duration and blood loss were preoperatively estimated to be 4 h and 500 ml. He had a history of prolonged intubation when he suffered a traumatic brain injury at 8 yr of age. He had epilepsy treated with phenobarbital but had no impairment of neurologic development and was cooperative. Despite undergoing tracheal resection and plasty for severe postintubation tracheal stenosis at 17 yr of age, he had relatively loud inspiratory and expiratory stridor while awake. Spirometry in the sitting position revealed reduced forced expiratory volume in the first second (FEV1= 1.95 l, 53%-predicted) and peak expiratory flow rates (PEF = 180 l/min, 30% predicted). Arterial blood gas analysis indicated mild impairment of oxygenation but normal ventilation (Fio2= 0.2, pH = 7.43, Pao2= 71 mmHg, Paco2= 33 mmHg). A flow-volume loop showed a typical upper airway obstruction pattern (fig. 1). Three-dimensional computed tomography (CT) of the trachea revealed severe intrathoracic tracheal stenosis more than 3 cm in length. In cross-section, the stenotic lesion was elliptical with a minor axis of 0.5 cm and a major axis of 1.5 cm (fig. 2). Despite the tracheal stenosis, he had no dyspnea during daily activities and was otherwise healthy. Nurses in the ward witnessed loud snoring and occasional apnea during sleep. Preoperative airway examination revealed Mallampati class 3, normal thyromental distance, and no limitation of neck or mandible movements. The orthopedic surgeons considered that neither conservative therapy nor surgery with regional anesthesia was appropriate because of his neurologic symptoms and the estimated operational duration and invasiveness of the surgery.Only the preoperative information with the figures described above was initially sent to both Drs. Asai and Cook. They were selected because of their previous reports of similar cases.3,4The following are their airway management plans for this patient.I follow an algorithm for anesthetic management of patients with tracheal stenosis based on its pathophysiology (fig. 3). Although the patient had relatively loud inspiratory and expiratory stridor and apnea during sleep, he had no dyspnea during daily activities. Therefore, I consider that spontaneous breathing or mechanical ventilation is likely to be possible through the stenosis with general anesthesia. Nevertheless, severe airway obstruction may occur during induction of general anesthesia, and thus the appropriate backup method will be required to prevent disaster.There are three possible methods for airway management of this case: (1) the use of a supraglottic airway alone, (2) the use of a supraglottic airway and a tube-exchange catheter, and (3) the use of a supraglottic airway, an endotracheal tube, and a tube-exchange catheter such as Cook Airway Exchange Catheter (Cook Medical, Bloomington, IN; 2.7 mm internal diameter [ID]). The choice of method would depend on both the risks of airway obstruction or dislodgement of the selected airway device and accessibility of the airway for reinsertion of the device.In this case, the airway might be managed with a supraglottic airway alone, but there are two major potential problems with this method: airway obstruction after induction of anesthesia and dislodgement of the supraglottic airway (particularly when the patient is turned to prone position from the supine position). One possible solution is to place the patient in the prone position and insert a supraglottic airway while the patient is still awake, and then induce anesthesia with increasing concentrations of sevoflurane while maintaining spontaneous breathing. Although the presence of the supraglottic airway would prevent airway obstruction above the vocal cords, worsening of the tracheal stenosis and hence severe airway obstruction may develop during inhalational induction with sevoflurane. In such a case, administration of sevoflurane should be terminated and the patient should be woken up. If inadvertent dislodgement of the airway device in the prone position is a risk, safety would be increased by prior insertion of a tube-exchange catheter, because this would enable both the maintenance of oxygenation until reinsertion of the supraglottic airway and the tracheal intubation through it.4,8Alternatively, a more conservative but a safer approach, which I consider the most appropriate in this case, is tracheal intubation with the two backup methods of the use of both a supraglottic airway and a tube-exchange catheter. In this case, the narrowest caliber of the trachea is 5 mm, and thus the largest size of an endotracheal tube, which can be passed through the stenosis, would be 4.0 mm ID, and ventilation may not be sufficient. Therefore, it would be necessary to insert a larger endotracheal tube with its tip proximal to the stenosis. Three-dimensional CT indicates that the stenosis is in the mid to lower trachea, and thus it would only be possible to insert the distal 3-4 cm of the endotracheal tube into the trachea, necessitating backup plans, in case of tube dislodgement. In such an event, either the supraglottic airway or the exchange catheter could then be used for maintaining oxygenation and reinserting the endotracheal tube. I would prepare for jet ventilation through the exchange catheter.After preoxygenation of the patient in the supine position, I would allow the patient to breathe increasing concentrations of sevoflurane in oxygen, and then assist ventilation manually via a facemask. After injection of a neuromuscular blocking agent, I would insert a Cook airway exchange catheter into the trachea under direct laryngoscopy, and then insert either the ProSeal Laryngeal Mask Airway ™ (PLMA ™; Laryngeal Mask Company, Henley-on-Thames, United Kingdom) #5 or i-gel (Intersugical Ltd., Wokingham, Berkshire, United Kingdom), another supraglottic airway, while the exchange catheter is placed outside the supraglottic airway. With the aid of a fiberoptic bronchoscope, I would pass a reinforced endotracheal tube through the supraglottic airway into the trachea so that the tip of the endotracheal tube is approximately 1-2 cm proximal to the stenosis. I would not inflate the endotracheal tube cuff, because it would be positioned at the glottis. Wrapping adhesive tape around the endotracheal tube at the connecter of the supraglottic airway would prevent both dislodgement of the endotracheal tube and gas leakage through the supraglottic airway. I would then adjust the position of the exchange catheter so that its tip is beyond the tracheal stenosis. After the patient is turned to the prone position, I would confirm (using a fiberscope) the appropriate positions of both endotracheal tube and exchange catheter. I would maintain the tidal volume as low as possible allowing hypercapnia to prevent excessive peak airway pressure. When possible, spontaneous breathing would be resumed. After surgery, I would remove the supraglottic airway once the patient has recovered from general anesthesia and is responsive to verbal commands, but would leave the tube exchange catheter in place, until it becomes certain that the patient can maintain a clear airway.This is a truly difficult patient. I would first reiterate to the surgeons that perioperative airway complications are a potential risk to the patient's life. The options of conservative treatment or transfer to a center with facility for combined tracheal reconstructive and trauma surgery must be explicitly considered.Assuming neither is possible I would premedicate the patient with a proton pump inhibitor 12 h before anesthesia. Two experienced anesthetists and an experienced anesthetic assistant would be required and briefed. I would start by placing a narrow gauge cricothyroid cannula specifically a 13-gauge Ravussin cannula (VBM Medizintechnik, Sulz, Germany) with local anesthesia and confirm its position by feeling expired gas, seeing gas exit through a bubble of saline and with capnography. If there was concern about the position of the Ravussin cannula, I would perform awake fiberoptic inspection to confirm its position before proceeding. Next, I would place a PLMA ™. If the patient was cooperative, I would do this during topical anesthesia. If he was not I would place it during general anesthesia. I would preoxygenate the patient fully with continuous positive airway pressure performed with at least 25 degrees head up position to increase lung volumes and maximize the apnea period before hypoxemia develops. I would administer a modest dose of opioid (e.g. , fentanyl 100 μg titrated in > 2-3 min) and propofol by target-controlled infusion. I would start with a low propofol effect site target (1-1.5 μg/ml) and increase this in steps of 0.5 μg/ml for every 1-3 min while maintaining spontaneous ventilation. At the point of eye closure, but before full anesthesia, I would assess ease of assisted ventilation. If ventilation was difficult or impossible, I would abandon this attempt and allow the patient to wake up. After confirmation of adequate mask ventilation, I would then paralyze with rocuronium, increase the depth of anesthesia, and insert a PLMA ™, using a bougie-guided technique.9,10After placement of the PLMA ™, I would then intubate the trachea through it. If the PLMA ™ was placed awake, I would induce anesthesia after PLMA ™ placement. For intubation, I would use a 4.2-mm fiberscope on which an Aintree Intubating Catheter (AIC; Cook Medical, Bloomington, IN) was mounted. After passage of the AIC, I would railroad a 6.5-mm ID intubating Laryngeal Mask Airway ™ (LMA ™) endotracheal tube over it. If the AIC passed easily, I anticipate that the intubating LMA ™ endotracheal tube would also pass. If the AIC was tight/snug, I would pass a Cook airway exchange catheter through the AIC and railroad a 5.0-mm ID microlaryngoscopy tube over the airway exchange catheter. I would then confirm position of the endotracheal tube beyond the stenosis. If the AIC could not pass without undue force, I would ventilate until paralysis was reversed (sugammadex may be useful here due to its ability to produce rapid and complete reversal of rocuronium paralysis) and then wake up the patient. During surgery, I would administer 8.0 mg of intravenous dexamethasone to minimize edema of the stenotic region. At the end of surgery, I would exchange the endotracheal tube for a Cook airway exchange catheter and a PLMA ™. I would then assess ease of ventilation (and spirometry) with the patient still anesthetized. I would then allow the patient to wake and remove the PLMA ™, but not the exchange catheter. If there was any suggestion of trauma during the intubation or concern about edema at the time of extubation, I would admit the patient to intensive care unit for 24-48 h of sedation, ventilation, and steroid to allow airway edema to settle.The history of tracheal surgery and persistent stridor suggested a rigid tracheal wall at the stenotic region allowing insertion of an endotracheal tube with 5-7 mm outer diameter, that is, only 4.0-5.5 mm ID without injuring the tracheal wall. We considered that positive pressure ventilation with such a small diameter tube might be difficult in this obese patient during surgery in prone position. Furthermore, traumatic insertion and prolonged placement of a larger diameter tube were considered to be disadvantageous because of the potential for development of mucosal edema and further narrowing of the trachea after tracheal extubation. Therefore, we decided not to intubate the trachea, but to use the PLMA ™ for positive pressure ventilation. The patient agreed with this strategy after we explained its potential benefits and risks to him.Because of clinical symptoms and body habitus suggesting potential obstructive sleep apnea, we performed nocturnal oximetry preoperatively. We calculated 4% oxygen desaturation index (i.e. , the average number of oxygen desaturations by 4% or more below the baseline level per hour). Although an oxygen desaturation index greater than 5 h−1is suggestive of sleep-disordered breathing, the index was 3 h−1in this patient.11Despite the negative result of the sleep study, nasal continuous positive airway pressure was prescribed because this could help maintain tracheal patency both for treatment of his snoring and in case of mucosal edema at the tracheal stenosis developed after surgery. The patient tolerated this treatment well.General anesthesia was induced with intravenous administration of remifentanil, propofol, and vecuronium, and a PLMA ™ (#5) was inserted, guided by a gum elastic bougie. Anesthesia was maintained with inhaled sevoflurane and an infusion of intravenous remifentanil. With pressure-controlled ventilation during surgery (peak inspiratory pressure 22 cm H2O, positive end-expiratory pressure 7 cm H2O, respiratory rate 8 breaths/min, inspiratory expiratory ratio 1:3) through the PLMA ™, we saw no signs of high airway resistance or airflow limitation such as low tidal volume or lack of formation of an alveolar plateau on capnography (tidal volume 730 ml, end-tidal CO231 mmHg). The surgery was uneventfully accomplished. The PLMA ™ was removed when the patient was fully aroused. Optimal postoperative analgesia was achieved by intravenous injection of nonsteroidal antiinflammatory drug and a continuous intravenous infusion of fentanyl. After the patient arrived on the ward, nasal continuous positive airway pressure with oxygen was applied immediately and was continued for three postoperative nights. This was effective in eliminating both snoring and stridor during sleep.12He did not complain of dyspnea after surgery and was discharged fully mobile.I believe that preoperative assessment and anesthesia management of the case described are generally reasonable and accord with my assessments and plans.The preoperative respiratory state during wakefulness and sleep was sufficiently assessed, and the visual assessments of the stenotic region with three-dimensional CT imaging of the trachea in addition to chest radiographs were informative. These meticulous assessments may certainly be useful to plan a safer anesthesia management (providing that the time and cost can be spent). Nevertheless, caution may be required, because the absence of significant airway obstruction during sleep does not guarantee that there will be no airway obstruction during anesthesia. There have been several reports of complete airway obstruction in patients with mediastinal without any preoperative signs of airway this case, the three-dimensional CT and preoperative assessments that complete airway obstruction is but it might have been safer to induce anesthesia by of increasing concentrations of a anesthetic as and then to a neuromuscular blocking after that no airway obstruction has may be two major possible problems with the anesthesia management performed by Drs. and may occur beyond the stenosis, when the ventilation is This can be reduced by the ratio is increasing the expiratory In this case, because the stenosis had a the pressure-controlled ventilation and ventilation volume was breathing might have been a choice ventilation had been during possible is that the use of the PLMA ™ might have difficult not likely in this the device had been or airway obstruction at the stenotic region had If there are about to the patient's or about a prolonged operation I would use a backup method of a tube-exchange catheter beyond the stenosis and an endotracheal tube with its tip proximal to the nasal continuous positive airway to minimize airway was applied for three postoperative nights. tracheal intubation not the choice of nasal continuous positive airway pressure than my plan of a tube to the trachea after possible solution that is several potential complications I will to the following I do not my plans would Drs. and have the of their plans In most in this case is not plan A is, but the plans to plan A immediately or is for the to have a plan as a before induction of first is that of this patient's care at the of supraglottic and problems to both difficult mask ventilation and difficult will be rapid and severe the airway is in this obese patient who will have a of a tube beyond his tracheal narrowing may be the most there are two patient that I the that the tracheal narrowing only 5 mm in its minor is mm in its major diameter to that it will admit a larger endotracheal tube than with an diameter of 5 The trachea is a and and who has tracheal will confirm that it will a larger diameter tube than its the that the patient no limitation to his daily activities indicates that gas flow is than of the patient's did consider use of the PLMA ™ as the airway anesthesia. The PLMA ™ is my airway and I have with it for both difficult airway is my in it that I have use of the ™ Mask because I believe that its and safety is to that of the PLMA ™. Despite I its use for this case because I was that it with the patient in the prone position, would be and might with did not consider the of use of PLMA ™ with an airway exchange catheter in place through the vocal in case was This is and a level of Despite I was required to this patient I would still tracheal intubation before a in the prone position. I have used the PLMA ™ in approximately patients in the prone position and I that it has been used in several of patients in the prone the patients in were at low risk and the largest is airway obstruction in three patients In the patient in this case has an increased risk of problems with both ventilation and degrees of and airway during surgery in the prone position would likely to airway If airway obstruction in this would likely be rapid and airway is likely difficult to in the supine position in Despite my I would be that problems in the prone position, would be so difficult to that the patient's would be at Despite the by intubation (and I would tracheal intubation in this spontaneous breathing induction of anesthesia, for a With the of I have a for use of a dose of target-controlled propofol, while maintaining spontaneous ventilation. There are only of this of target-controlled infusion of propofol over rapid intravenous induction is that spontaneous ventilation is The also has over propofol that the of anesthesia. increasing depth of anesthesia is of the patient's ventilation. This rate of increase of the depth of anesthesia to be titrated by the than by the also that is the infusion immediately anesthesia to without the patient to anesthesia via an airway that was and has airway are so increased and the complications to during induction are In patients will ventilation when still responsive to verbal This confirmation of ability to or of increasing and airway (e.g. , are tolerated and than during the does to to problems with the airway PLMA ™ is a device with a in management of the difficult there is in PLMA ™ it is that insertion can be more difficult than for supraglottic airway insertion enable a insertion rate with the PLMA ™ of lower than that for the is that the use of a first pass with the PLMA ™, increasing to without any increase in in I consider first time to be I insert the PLMA ™ over a gum elastic the type of is to minimize the risk of AIC is the tube to use to intubate via a supraglottic airway and intubate narrow has the diameter than of any endotracheal tube that will over a size fiberscope and its ID that it does not during on the use via the and PLMA ™ in difficult airway management is in two placed it oxygenation and on placement of a larger endotracheal tube over or a an airway exchange catheter through by the small minor diameter of the trachea the significant of with ventilation or If ventilation becomes at any after induction or intubation with an AIC is not possible, my plan is before another are before any have been I would at an endotracheal tube, tracheal the of loss of the airway, with my will be ventilation using a (VBM Medizintechnik, Sulz, the a so that the may only the pressure to ventilate the the risk, and of any would be via the Ravussin cannula, placed before induction of anesthesia. and a is not an time to place a cricothyroid cases of difficult airway management which to of cases with and in of cases a surgical airway was but was placed to and ventilation performed in were with a high incidence of Although cases are by the is for and a patient before is a The of insertion of a cricothyroid cannula for difficult airway management has been is a of my management of patients with airway is performed in the awake is and is the catheter would be placed under as this position and in this case that may not be is more when the is before difficult that may I to use the cricothyroid cannula I would not anticipate with but care would be to that full had over or before the placing a on the patient's chest and complete chest is a useful to confirm complete would to severe in clinical anesthesia, there may be no or several appropriate The airway airway management strategies for this patient. this does not airway through this case scenario, of the is that we agreed that ventilation would be possible during anesthesia Despite did we airway management strategies and in plans in case of this is either because preoperative assessments of airway size and may be in ease of ventilation during general anesthesia or because the airway management and for managing tracheal stenosis is also in patients with severe tracheal stenosis, normal gas exchange is maintained by respiratory Therefore, the presence of hypercapnia in preoperative patients without respiratory indicates the potential for of both spontaneous and mechanical ventilation during general anesthesia. In the ability to breathing through a narrow airway is during general anesthesia and than that during because such as and are and oxygen is and breathing through a of mm ID and cm in or mm ID and cm in reduced the ventilation by 7 and during general anesthesia, were and The by and and confirm that the narrowing through which patients can breathe without an increase in mm for breathing through a is achieved by the respiratory with of both inspiratory and expiratory and the increase in respiratory Although the patient's respiratory or during assisted and ventilation, size of the stenosis for breathing may not be by the I that no has the stenosis for mechanical ventilation in and patients and the to be in the can we assess and severity of tracheal with mild to tracheal stenosis have clinical symptoms such as patients with severe tracheal stenosis may present without stridor and dyspnea during breathing clinical symptoms may not be for severity of tracheal imaging assess the severity of the stenosis. radiographs have clinical for the presence and the severity of an airway stenosis. CT the airway significant information the and of the airway narrowing and the the developed three-dimensional imaging such as CT and imaging can more airway and the airway a fiberoptic for the and the the and the of stenotic region of the trachea in patients who trachea surgery were to be mm in and mm, suggesting of the and of the stenotic airway by the imaging of the tracheal stenosis on breathing during general anesthesia is difficult to by the imaging size is by the pressure the airway wall and its A extrathoracic airway during and during because the pressure during and during In the airway caliber and respiratory is in the intrathoracic airway. Therefore, airflow limitation not occurs in the extrathoracic airway during and in the intrathoracic airway during airway is during forced expiratory and inspiratory particularly when of the airway caliber is In this may be useful for the site of airway and airway that the during a of forced expiratory and inspiratory were greater in 12 patients with extrathoracic airway than of normal Two patients with intrathoracic had than which increased to more than after of the mediastinal and insertion of tracheal In two patients with tracheal stenosis, both and were but did not from normal to the flow-volume loop in patient had significant in both and and a normal ratio suggesting significant airway stenosis and for of the airway wall. Nevertheless, caution is required for of the because can be by patient a direct the tracheal by the CT and in with mediastinal significant but in the supine position with the sitting position and significant in after mass complete airway obstruction after induction of anesthesia in with greater than tracheal the patient with a trachea by lower and tracheal should not have general anesthesia induced before the airway. In may be useful for tracheal and for the risk of airway after induction of anesthesia, but further are the airway is the severity of airflow limitation is by airway the a significant and the of the airway stenosis, and might be used as a useful for airway size without imaging of the of the of stenotic and airway to airway may have over imaging information as an index for upper airway that was greater than in patients with upper airway to a normal breathing through an resistance of than mm diameter (fig. through a in mechanical ventilation during general anesthesia, increased the to more than In patient with 3 cm tracheal stenosis with of is calculated as = The is than that in normal and to breathing through at to 8 mm Therefore, this assessment possible breathing or mechanical ventilation during general anesthesia, airway This assessment of the tracheal stenosis can significant information for perioperative airway management strategies (fig. 1). of more than to 4 mm may a potential of mechanical ventilation after induction of general anesthesia, this to be and should be considered in we anesthetic management of a patient with tracheal stenosis and airway management strategies of and accurate of airway patency and breathing during general anesthesia in the patient with tracheal stenosis to be the for the airway management For patients with difficult in preoperative airway assessment as a is when with the in airway management and Cook United United and United with of the case assisted in of and of the of for his with of this

To the Editor, Exchanging an endotracheal tube (ETT) for a supraglottic airway (SGA) has been described for smooth tracheal extubation and to help the patient avoid coughing at the time of emergence from anesthesia. This technique is also one of the three advanced extubation methods recommended by the Difficult Airway Society in their recent extubation guidelines. Nevertheless, there is a possibility of losing the airway during the exchange procedure. We describe a novel technique to establish a bridging SGA by utilizing an airway exchange catheter in a patient with a difficult airway. Patient consent for publication was obtained. A 38-yrold woman weighing 60 kg was scheduled for a total thyroidectomy. Her airway assessment revealed limited neck extension, receding chin, and a Mallampati grade 3 view. Direct laryngoscopy showed a grade 3 view with external laryngeal pressure, and the patient’s trachea was intubated with a 7.5-mm internal diameter ETT over an Eschmann tracheal tube introducer (gum elastic bougie). At the end of the surgery, the surgeon requested a smooth extubation with minimal cough. We planned on a bridging laryngeal mask airway (LMA) extubation technique. End-tidal sevoflurane was increased from 1 to 1.5 MAC, and 2% lidocaine 3 mL was sprayed endotracheally. The patient was maintained with positive pressure ventilation. An airway exchange catheter (19F, Cook Inc., Bloomington, IN, USA) was then inserted inside the ETT up to the 30-cm mark at the incisors and the ETT was removed. The exchange catheter was inserted into the airway tube lumen of a size-3 LMA-ProSeal (Canada Teleflex Medical, Markham, ON, Canada), and the LMA was placed into the pharynx without the metal introducer. An elbow connector with a bronchoscopy port was connected to the LMA-ProSeal with the proximal end of the exchange catheter protruding through the port (Figure). The proximal tip of the exchange catheter was occluded with tape to avoid backward air leak. The exchange catheter was removed after ensuring adequate positioning of the LMA-ProSeal by normal capnography waveform and confirming no cuff leak. The patient was then allowed to emerge from anesthesia, at which time, she could obey commands, spontaneous breathing was observed, and the LMA-ProSeal was removed without the patient coughing. If either positive pressure or spontaneous ventilation via the LMA-ProSeal had been inadequate, the ETT could have been reintroduced over the exchange catheter, followed by a conventional extubation technique. Two techniques of exchanging an ETT for a SGA at emergence have been described previously: 1) ETT removal followed by blind SGA insertion, or 2) the Bailey maneuver with insertion of a SGA behind an ETT followed by ETT removal. We consider our exchange technique to offer two potential advantages. First, because the SGA was inserted into the pharynx, over an exchange catheter, the LMA was probably positioned more precisely than with a blind insertion. Second, with the exchange catheter remaining in situ after ETT removal, reinsertion of an ETT could be readily accomplished should ventilation through the SGA fail. To perform this exchange technique, any SGA and exchange catheter or intubation introducer can be used. During this exchange process, it is essential to maintain adequate levels of anesthesia to avoid stimulation of the airway. R. Raveendran, MD S. G. Sastry, MBBS D. T. Wong, MD (&) Department of Anesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada e-mail: David.Wong@uhn.ca

Most airway management in anaesthesia is safe, but infrequent disasters still occur and these were brought into focus by the 4th National Audit Project (NAP4) of the Royal College of Anaesthetists and Difficult Airway Society (DAS) ( Cook et al, 2011a ). Advances in airway management have included continued development of new devices in the last few years. Second-generation supraglottic airway devices, videolaryngoscopes and equipment for emergency surgical airway are the most notable. The complications associated with the use of some devices (e.g. airway exchange catheters) have been brought into focus. Safe airway management has also been supported by an increasing understanding of the human factors involved in successful, and unsuccessful, airway management and by the introduction of guidelines (particularly those of the Difficult Airway Society). This article reviews all these topics and other recent advances.

11059 Background: Some opioid stewardship policies could negatively affect patients with cancer pain. However, patients with cancer are also at risk for opioid related harms, especially with persistent use. We assessed opioid prescribing trends in the context of cancer treatment and patient reported pain in a large health system in Connecticut. Methods: We conducted a retrospective cohort study of opioid-naïve adult patients with solid tumor malignancies diagnosed from 2016 through 2020 within the Yale New Haven Health System. We identified new (≥1 opioid prescription in 0-6 months following diagnosis) and additional (0-6 and 6-9 months) opioid prescriptions. The analysis evaluated all eligible patients as well as two clinical cohorts: patients treated surgically and patients with metastatic cancer. For patients with metastatic cancer and a documented pain score in the electronic health record flowsheet data, we further stratified by any (any score≥1) or no (all scores=0) pain in the 6 months since diagnosis and prior to first opioid, if given. For these patients, we noted therapeutic class of the first opioid. We used a logistic model adjusted for patient demographics to calculate predicted probability of opioid prescription and change over time. Results: A total of 10,868 patients met study criteria. Overall, we observed a decline in new opioid prescribing from 69.0% to 62.7% (p<.001) (Table). Additional opioid use also declined from 23.4% to 20.2% (p=.02). In the surgery cohort, new opioid prescribing fell from 95.7% to 88.2% (p<.001), while additional opioid use was stable over time (approximately 12%). For patients with metastatic cancer with any documented pain, new opioid prescribing was stable over time (approximately 56%). For those with documented pain scores=0, new opioid prescribing declined from 59.7% to 34.2% (p<.001). In these patients, the class listed on the first opioid prescription was analgesia in 86.6% and cough in 13.4%. Conclusions: Overall, and in patients treated with oncological surgeries, our study in a single large US health system suggests a modest, gradual decline in opioid prescribing for patients with cancer over time. On the other hand, among patients with metastatic cancer, opioid prescribing remained stable for those with documented pain and declined steeply for those without documented pain. [Table: see text]

The case presented by Mathew et al. in this issue of Anesthesia & Analgesia presents us with an opportunity to explore a broader view of difficult airway management: first, how a situation or context influences our approach to the problem; second, the “unwritten truth” of bronchoscopic intubation; and third, the importance of gas-exchange preservation over devices and techniques. In Chinese, the written word for “crisis,” “Wei Ji,” is formed by combining 2 separate words: “Wei” or “danger” and “Ji” or “opportunity.” This combination most likely originated from ancient teachings about how to live a life that thrives while responding to unpredictable mystical, political, and environmental forces. This frame of reference reflects a deep-seated philosophy of cultural survival. History provides a unique context that has resonance and reverberations in this day and age. In other words, although what we do today is often shaped by history and guided by evidence, our actions are frequently tempered by the circumstances (or “context”) in which we act. It has been said that we are in the midst of a medical-legal “crisis.” Perhaps, as the ancient Chinese did, we ought to seize this as an “opportunity,” though alert to the “danger” posed by this “crisis.” But in this modern context, the “opportunity” is shaped by evidence rather than mystical, environmental, and political forces. Caplan et al. first reported alarmingly poor outcomes related to the management of the difficult airway in their review of the American Society of Anesthesiologists (ASA) closed claims database in 1990. They reported that adverse outcomes associated with respiratory events constituted the single largest class of injury, and litigation, in anesthesia in the United States (34%). The review also identified that most of these airway management–related adverse respiratory outcomes were preventable. Recognizing that reversing this finding was paramount to our specialty, the ASA formed a task force to review the existing evidence and to recommend corrective airway management strategies. The ASA Difficult Airway Algorithm and Guidelines were published in 1993 and subsequently revised in 2003. Although there are limitations to the recommendations, the ASA guidelines provide clinicians with an evidence-based approach to the airway evaluation and management of patients about to undergo an anesthetic. Although it is difficult to assess the true impact of these guidelines on clinical outcomes, a recent review of the closed claims database showed that there are signs of improvement, with reduction in the number of adverse events (especially death and brain death) associated with airway management misadventures. Unfortunately, this improvement was limited to the management of the airway on induction of anesthesia, but not outside the operating room. Clearly, continuing efforts to increase awareness of the difficult airway and improve airway assessment and education, coupled with the enhancement of predictive and management strategies, are crucial to the difficult airway management approach in a controlled environment. The findings of Peterson et al. also suggest that a broader understanding and approach to airway management is needed to improve overall outcome. During the last 2 decades, many new airway devices and techniques have been developed, and these have changed the landscape of airway practice and management. In addition, there has been a major paradigm shift in airway management, emphasizing gas exchange (ventilation and oxygenation) over tracheal intubation. Clinicians use only 4 methods of ventilation and oxygenation: a bag mask, an extraglottic device (e.g., a laryngeal mask airway), a tracheal tube, and a surgical airway. Selection of one of these techniques to provide gas exchange depends not only on the devices best suited to the patient’s anatomy but also on the situation faced by the clinician. In other words, airway management is “context sensitive” in that it is heavily dependent on the clinical situation and the environment. If, for instance, a patient presents with a history or clinical features predictive of an “impossible” tracheal intubation using a laryngoscope, and also possesses predictors of difficult bag-mask ventilation and difficulty in using an extraglottic device, such as the laryngeal mask airway, it would be prudent for the clinician in the setting of an operating room to secure the airway awake, frequently utilizing a flexible fiberoptic bronchoscope. However, the management plan would be quite different if this same patient required airway management in the prehospital setting, in the emergency department, or in the magnetic resonance imaging suite where skill sets and limited resources play decisive roles. The selection of an airway approach might also be different if the patient requires immediate and rapid emergency airway intervention, if the patient is a small child who is extremely uncooperative, or if the patient is pregnant. There are From the Department of Anesthesia, Dalhousie University, Queen Elizabeth II Health Sciences Centre, Halifax, Nova Scotia, Canada.

If You’ve Seen One EMS System, You’ve Seen One EMS System…

Pragmatic recommendations for intubating critically ill patients with suspected COVID-19.