Abstract
A 78-yr-old woman presented for a panendoscopy to investigate dysphonia and dysphagia. Intubation was anticipated to be difficult but possible, and mask ventilation was anticipated to be possible. After induction of anaesthesia and after three attempts at intubation, a ‘can't intubate, can ventilate’ situation deteriorated to a ‘can't intubate, can't ventilate’ (CICV) situation. Rocuronium-induced neuromuscular block was successfully reversed with sugammadex, as evidenced by the restoration of diaphragmatic movement, the ability of the patient to move her limbs, and the presence of a train-of-four nerve stimulation with no fade; however, ventilation was still not possible. A cricothyroid puncture using a Ravussin needle was performed successfully to provide emergency oxygenation. A tracheostomy was performed to allow the panendoscopy. CICV situations are rare anaesthetic emergencies. While sugammadex can be relied upon to reverse rocuronium-induced neuromuscular block, it should not be relied upon to rescue all CICV events, especially where airway instrumentation has led to airway swelling. The availability of sugammadex does not obviate the need for emergency tracheal access in the event of failed oxygenation. The presence of head and neck pathology should lead to the consideration of securing the airway awake.
Sugammadex reversal of rocuronium has been suggested for management of a difficult airway.
In a patient with upper airway pathology, attempts at tracheal intubation resulted in a ‘can't intubate, can't ventilate’ situation.
Sugammadex reversed the rocuronium but did not restore airway patency.
Alternative strategies for airway management must be immediately available.
Sugammadex is a modified γ-cyclodextrin that rapidly and completely reverses the neuromuscular block associated with rocuronium.1 Even at high doses of rocuronium (1.2 mg kg−1), reversal by high-dose sugammadex (16 mg kg−1) is faster than the spontaneous recovery from 1 mg kg−1 of succinylcholine.2 This rapid reversal of neuromuscular block has led to sugammadex being suggested as a rescue drug in a ‘can't intubate, can't ventilate’ (CICV) scenario3,4 after administration of rocuronium. We report what we believe to be the first case of the use of sugammadex in a CICV scenario, which highlights that rapid reversal of neuromuscular block with sugammadex will not relieve necessarily airway obstruction caused by the instrumentation of a compromised airway and that it is not a substitute for emergency tracheal access.
Case report
A 78-yr-old woman (65 kg) with a 4 month history of dysphonia and dysphagia presented for an elective panendoscopy and left-sided tonsillectomy. She denied any symptoms of orthopnoea or stridor, and otherwise her medical history was unremarkable. Airway assessment revealed a Mallampati score of 3, with a 4 cm mouth opening, thyromental distance of 7 cm, and full dentition. Nasendoscopy performed by a consultant head and neck surgeon 2 weeks previously had revealed a swelling in the left tonsil with oedematous uvula which partially obscured the view of the pharynx, but the vocal cords and larynx appeared normal. A CT scan performed the day before surgery reported a large enhancing mass lesion in the region of the left palatine tonsil with significant bilateral cervical lymph nodes and narrowed airway at the level of the hyoid.
The discrepancy between the findings of the nasendoscopy and CT scan was discussed between two experienced consultant anaesthetists and a consultant head and neck surgeon in order to formulate plans for securing tracheal intubation. An awake fibreoptic intubation was considered. Intubation was anticipated to be difficult, although mask ventilation was anticipated to be possible. A stepwise plan for intubation was agreed. The initial plan was, therefore, induction of general anaesthesia with direct laryngoscopy, with a secondary plan of the use of an alternative blade, videolaryngoscope (Glidescope™; Verathon Inc., WA, USA), or a fibreoptic bronchoscope, depending on the difficulty encountered. The tertiary plan was to wake the patient up, reversing the rocuronium-induced neuromuscular block with sugammadex. The sugammadex was brought into the anaesthetic room and a 16 mg kg−1 dose was calculated but not drawn up. In the event of failed oxygenation, a cricothyroid puncture was planned and a Ravussin needle (VBM Medizintechnik, Sulz, Germany) and Manujet (VBM Medizintechnik) were immediately available. The placement of a Ravussin needle pre-induction was not deemed necessary, given that ventilation was anticipated to be possible. All of the equipment required for each of the plans was prepared in the anaesthetic room. As is usual, the theatre nursing team were also alerted to the anticipated difficulty with intubation, management plans discussed, and they prepared a tracheostomy kit as a precaution.
The patient was pre-oxygenated for 4 min and then anaesthesia induced with fentanyl 75 µg administered i.v. followed by propofol 160 mg. This was followed immediately with rocuronium bromide 40 mg (0.61 mg kg−1) to achieve muscle relaxation. Bag-mask ventilation was easily achieved and the lungs were ventilated with oxygen at an 
of 1.0 and sevoflurane at an end-tidal concentration of 1.9%. After 2 min, gentle direct laryngoscopy was performed with a Macintosh size 3 blade. On laryngoscopy, the anatomy was unidentifiable because of a large, rigid, fungating mass in the oropharynx and obliterating any view of the larynx or epiglottis. Direct laryngoscopy was abandoned and bag-mask ventilation successfully recommenced. Indirect laryngoscopy with the Glidescope was attempted to try and bypass the mass. This did not improve laryngoscopy and contact bleeding had commenced, so bag-mask ventilation was successfully re-instigated. A second consultant anaesthetist performed direct laryngoscopy with a size 4 Macintosh blade which was also unsuccessful. Bag-mask ventilation had now become increasingly difficult, despite the use of a Guedel airway and two-person mask ventilation. A size 3 laryngeal mask airway (LMA Unique™, Intavent Orthofix, Berks, UK) was inserted; however, ventilation was not possible and so it was removed.
A CICV scenario was now recognized and the decision made to awaken the patient. Oxygen saturation levels remained at 98%. The volatile agent was turned off, and sugammadex 1 g (15.4 mg kg−1) administered given i.v. within 30 s of the decision to awaken the patient being made. This was ∼6 min after the administration of rocuronium. A nerve stimulator was attached to the patient. Further attempts at ventilation continued unsuccessfully. After 60 s, spontaneous chest wall movement was observed with the patient beginning to make respiratory effort and moving her upper limbs. Train-of-four nerve stimulation showed no evidence of fade. An obstructed pattern of breathing was witnessed with no capnography trace or movement of the reservoir bag. Oxygen saturations had now decreased to 92%, so an adult Ravussin cannula was inserted through the cricothyroid membrane to achieve rescue oxygenation. Placement was confirmed with aspiration of air and evidence of carbon dioxide on capnography, followed by oxygenation with the Manujet™ set to an initial pressure of 0.5 bar and a rate of 5 bpm. Adequate inhalation and exhalation was confirmed by the rise and fall of the anterior chest wall, with upper airway manoeuvres being used to maintain a route for exhalation. The driving pressure was subsequently increased to 1 bar to achieve adequate tidal volumes and oxygen saturation levels increased to 98%.
An emergency tracheostomy was performed between the first and second tracheal rings by the surgical team with anaesthesia maintained using i.v. propofol. A 7.0 mm cuffed tracheostomy tube was inserted and conventional ventilation achieved followed by a panendoscopy and tonsillar biopsy. After the procedure, anaesthesia was discontinued and the patient woken up. She was nursed on the high dependency unit overnight, before returning to the ward. There was no neurological deficit. Histology showed a squamous cell carcinoma and a tracheostomy remained in situ while the patient underwent treatment for the tongue base tumour.
Discussion
CICV situations are an anaesthetic emergency requiring rapid and decisive management. Given the rarity of CICV events, the incidence is difficult to estimate; however, recent work has suggested an incidence during all anaesthetics of one in 50 000.5 It is likely that the incidence is higher in patients with head and neck pathology. Both the ASA6 and the Difficult Airway Society (DAS)7 have published guidelines on the management of CICV situations. The introduction of sugammadex, with its rapid reversal of even profound neuromuscular block, has led to the suggestion that it is a potential rescue strategy in CICV situations.3,4,8,9
A CICV scenario may be induced through multiple airway manipulations occurring during either the unanticipated or anticipated difficult intubation, which may cause swelling or soiling of the airway, as occurred in our case. Indeed, the recently published Fourth National Audit Project of the Royal College of Anaesthetists and Difficult Airway Society (NAP4) report found that in head and neck pathology, repeated attempts at laryngoscopy were a common cause of airway deterioration and morbidity.10 The use of sugammadex in these situations will reverse rocuronium neuromuscular block, as occurred in our case as shown by the presence of a train-of-four with no fade leading to the return of respiratory efforts, although this may not be associated with a restoration of a patent upper airway. The end-result of CICV (failure to oxygenate) would still be present. In these circumstances, then rescue oxygenation strategies, such as the placement of a cricothyroid puncture device, must be used while an emergency definitive airway is secured.
CICV scenarios may be apparent immediately after the onset of anaesthesia, for example, failed ventilation in the morbidly obese when associated with difficult laryngoscopy. In situations such as this, where the CICV scenario occurs before there have been multiple airway manipulations, the reversal of rocuronium-induced neuromuscular block with sugammadex and the return of upper airway tone is likely to restore a patent airway. However, this is reliant on the correct dose of sugammadex being immediately available and easily accessible. A recent manikin study stated that in a CICV scenario, the time to calculate the correct dose of the drug and draw it up is 6.7 min.11
Our case illustrates that sugammadex, while completely reversing rocuronium-induced neuromuscular block, did not rescue a CICV situation, and that it is not a panacea for all anticipated and unanticipated difficult airway management. Sugammadex may have a role in the management of CICV situations of different aetiology; however, rescue oxygenation techniques should be used in a timely fashion if required. If sugammadex is part of a rescue management plan, then it should be used early in the management of the difficult airway situation, before repeated airway manipulations. It also highlights that an airway management plan needs to be reassessed in the light of new investigations and supports the NAP4 recommendations of the avoidance of multiple attempts at laryngoscopy.10 A repeat nasendoscopy would have been appropriate to investigate the discrepancy between the previous nasendoscopy and the CT scan and would have likely led to the further consideration of some form of awake airway management, such as fibreoptic intubation or a prophylactic cricothyroid cannula. Given the situation encountered at laryngoscopy, it is possible that an awake fibreoptic intubation may have failed. Finally, it is important that all members of the operative team are briefed in advance of any potential difficulties and are aware of a stepwise plan in order to allow adequate preparation and effective management of such emergencies.
Declaration of interest
None declared.
Acknowledgement
Consent for publication was granted by the patient.
Comments
We thank all correspondents for the interest in our case report (1). In particular we thank Doctors Ezri and Evron for highlighting another case report of the use of sugammadex in a "can't intubate, can't ventilate" by Desforges and McDonnell (2), which, at the time of submission of our own case report, had not been published. A number of other issues are raised in other letters that merit further attention.
The management strategy that we chose was deemed to be the best and safest plan in the circumstances. Others may disagree on our choice of technique. However, it has been shown by Cook et al (3) that airway management experts have very different views on how to manage a problematic airway, with some experts specifically saying not to employ a particular technique when others choose the same technique as the optimum way of managing a case.
One of the letters refers to a paper by Mason and Fielder (4) which states that in the management of such patients, there are only two ways of managing the airway; inhalational induction or awake tracheostomy. We feel it is important to point out that this is an editorial, which by definition is the opinion of the authors, reinforcing the recent findings of Cook et al. Also, several of the letters received describe the use of awake fibreoptic intubation in the management of such patients, which further serves to support the findings of Cook et al.
The use of an inhalational induction as a method of securing the airway also merits attention. In the NAP4 report (5), one of the themes to emerge was the "deterioration in the airway following inhalational induction and the subsequent inability to maintain spontaneous ventilation" in head and neck pathology cases. In the cases reported to NAP4, in only 4 of 27 (15%) inhalational inductions there was no compromise to spontaneous ventilation, whereas 9 of 23 (39%) of flexible fibreoptic techniques were successful. Can inhalational induction therefore confidently be regarded as one of the only two ways of managing the partially obstructed airway?
The concept of "proactive" and "reactive" airway management by Watson, Jefferson and Ball is an interesting one. The Difficult Airway Society guidelines (6) are an example of a reactive form of airway management, whereas the American Society of Anesthesiologist's guidelines (7) are perhaps more proactive. The Aintree Difficult Airway Management (ADAM) website could be described as the most proactive resource for airway management available at present. Arguably, for anticipated difficult airways, a proactive approach would be more appropriate than a reactive one, whereas by their nature, unanticipated difficult airways require a reactive approach.
We are glad that our case report has stimulated discussion, and hope that it has highlighted the core messages, namely that sugammadex should not be regarded as a substitute for emergency oxygenation techniques, the importance of reassessing the airway with nasendoscopy in the light of conflicting investigations and adapting the management accordingly. Although some may consider this "common sense", we thank those who, with the benefit of hindsight, recognise the importance of our case report by offering insightful and constructive critiques. This is the essence of an open culture to improve patient safety and the purpose of sharing such experiences.
R. Curtis, S. Lomax, B. Patel
Guildford, Surrey, UK
1. Curtis R, Lomax S, Patel B. Use of sugammadex in a "can't intubate, can't ventilate" situation. British Journal of Anaesthesia 2012; 108: 612-614.
2. Desforges JCW, McDonnell NJ. Sugammadex in the management of failed intubation in a morbidly obese patient. Anaesthesia and Intensive Care 2011;39:763-4
3. Cook TM, Morgan PJ, Hersch PE Equal and opposite expert opinion. Airway obstruction caused by a retrosternal thyroid mass: management and prospective international expert opinion. Anaesthesia 2011; 66 (9): 828- 836
4. Mason RA, Fielder CP. The obstructed airway in head and neck surgery. Anaesthesia 1999; 54: 625-8.
5. Major complications of airway management in the UK: results of the 4th National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part 1 Anaesthesia. Cook TM, Woodall N, Frerk C. British Journal of Anaesthesia 2011; 106: 617-31.
6. Henderson JJ, Popat MT, Latto IP, Pearce AC. Difficult Airway Society guidelines for the management of the unanticipated difficult intubation. Anaesthesia 2004; 59: 675-94.
7. Caplan RA, Benumof JL, Berry FA, et al. Practice guidelines for the management of the difficult airway; an updated report by the American Society of Anesthesiologists Task Force on the management of the difficult airway. Anesthesiology 1993; 98: 1269-77.
Conflict of Interest:
All authors of this letter were the authors of the original publication "use of sugammadex in a "can't intubate, can't ventilate" situation (BJA 2012; 108:612-614).
We currently see a very low threshold to do awake endoscopic intubations (AEI). The reasons are multitude lack of equipment, time restraints, training, confidence in asleep technique comparison to awake technique, anxiety about discomfort to patients, etc. Awake endoscopic intubation is ideal for this scenario because of the conflicting CT report to nasal endoscopy and for the patient's safety, which is of paramount importance.
An asleep endoscopic intubation possibly is the second choice with the availability of a maxillofacial surgeon or an ENT surgeon, as in this case. The anaesthetic technique can be TCI, TIVA with remifentanil, propofol or inhalational agents as per the anaesthetist's choice. But this has to be backed up by a cricothyroid cannula done awake earlier for jet ventilation. The reasons as for not using awake endoscopic intubation apply for not using cricothyroid cannulation and jet ventilation. An LMA could help with either the endoscopic technique or the surgeons to do the tracheostomy with spontaneous ventilation. But the key point is to avoid muscle relaxant till the airway is secured. But I understand there is still a controversy about ease of ventilation with muscle relaxants. The role of second generation video laryngoscopes i.e. CMAC, Airtrach, glidoscope is not clear in such scenarios.
Anticipated difficult airway and muscle relaxant is not an ideal partnership even with the availability of good reversal agents. This patient was managed successfully by experienced anaesthetist but any situation like this without immediate surgical backup is disastrous for the patient. The readers of this article must take this into consideration.It would be not realistic to expect guidance from Difficult Airway Society (DAS) for every possible scenario like anticipated difficult airway but possible ventilation. We as a group of clinicians should take every possible step for patient safety within the realms of availability, training and experience.
Conflict of Interest:
None declared
To the Editor
In the April issue of British Journal of Anesthesia, Curtis et al (1) presented an interesting case in which a patient with anticipated difficult intubation, was paralyzed with rocuronium and developed a cannot intubate/cannot ventilate (CI/CV) situation. Sugammadex was administered resulting in successful recovery of the patient's motor strength but ventilation was still impossible, presumably due to swelling of the airway and bleeding caused by repeated intubation attempts. The patient's life was saved by timely performing of transtracheal needle oxygenation followed by an emergency tracheostomy. In the article, the authors claim they report what they believe "to be the first case of the use of sugammadex in a CI/CV scenario". However, we found a case published before by Desforges and McDonnell (2), of sugammadex administration in a CI/CV scenario. In their case, a patient with a BMI of 38.5 kg/m2 and Mallampati class 3 scheduled for sleeve gastrectomy, received rocuronium to facilitate endotracheal intubation which proved to be impossible. Considering that "no convincing capnography trace could be detected while the SpO2 decreased to 69%", sugammadex was administered and successfully reversed the CI/CV condition enabling effective spontaneous ventilation within 45 seconds of sugammadex administration. We consider the case report by Curtis et al important for three reasons. First, we congratulate the authors for their systematic, step-by-step planning of anesthesia and airway interventions in this case. Secondly, this case demonstrates what appears evident that sugammadex will not recover an effective spontaneous ventilation in all CI/CV cases. Repeated laryngoscopy and intubation attempts may cause airway edema with obstruction and difficult ventilation even with regained motor strength. Furthermore, the patient may not be able to ventilate spontaneously due to the administration of central nervous system depressants (i.e. midazolam, fentanyl) during induction of anesthesia. Thirdly, this case re-emphasizes the need for considering the performance of an awake intubation technique whenever facing a predicted airway management difficulty. It is our routine to opt for awake fiberoptic intubation whenever we expect a difficult-to -manage airway. The use of a short acting muscle relaxant such as succinylcholine, hoping for a quick recovery of spontaneous ventilation in case a CI/CV will develop seems unsafe as well. Benumof et al (3) mentioned that the time to functional recovery (i.e 50% recovery of the control single twitch height of the adductor pollicis brevis muscle), a time that should permit adequate spontaneous ventilation with a patent airway after 1 mg/kg succinylcholine was reportedly 8.5 min. They also mention that the majority of patients will develop life- threatening hemoglobin desaturation before functional recovery.
Tiberiu Ezri, MD Shmuel Evron, MD Department of Anesthesia, Wolfson Medical Center, Holon, Affiliated to Tel Aviv University, Israel and Outcomes Research Consortium, Cleveland OH, USA
[email protected]
References
1. Curtis R, Lomax S, Patel B. Use of sugammadex in a "can't intubate, can't ventilate" situation. Br J Anaesth 2012;108:612-4. 2. Desforges JCW, McDonnell NJ. Sugammadex in the management of failed intubation in a morbidly obese patient. Anaesth Intens Care 2011;39:763-4. 3. Benumof JL, Dagg R, Benumof R. Critical hemoglobin desaturation will occur before return to an unparalyzed state following 1 mg/kg succinylcholine. Anesthesiology 1997;87:979-82.
Conflict of Interest:
None declared
We read with interest the case report by Dr R. Curtis. et al describing the use of Sugammadex in a "can't intubate, can't ventilate situation".1 It again emphasizes the recent recommendations from the National Audit project 4 (NAP4) in the United Kingdom and results of previously published literature on consequences of repeated attempts at endotracheal intubation.2, 3 Safe management of the airway relies on the principle of avoiding trauma to the airway, so as not to compound existing difficulty. The authors had formulated primary, secondary and tertiary plans to manage the airway. Though it is mentioned that awake fibreoptic endotracheal intubation was considered, the reasons for not considering it as the primary plan are not mentioned.
Preoperative nasendoscopy in the anaesthetic room has been shown to be a useful additional investigation 4,5 in aiding decision making to undertake an awake fibreoptic intubation. When the preoperative nasendoscopy and CT scan in this case, yielded different results with regards to the extent of the mass, a repeat nasendoscopy prior to proceeding with securing airway would have been helpful. It is not uncommon for lesions to increase in size in the interim period between being seen in clinic and the time of surgery.
Though the strategy in this case was to perform a direct laryngoscopy (DL) as the primary plan and indirect laryngoscopy using the Glidescope or fibreoptic scope as a secondary plan, there appears to be a deviation from the strategy during execution. Direct laryngoscopy was attempted again following a failed attempt with Glidescope, i.e., moving back from the secondary plan to an unsuccessful primary plan. Videolaryngoscopy (Glidescope) helps in looking round the corner with out the need for alignment of oropharyngolaryngeal axis and provides an indirect and superior view of larynx compared to direct laryngoscopy,6 hence we feel that the direct laryngoscopy following attempted videolaryngoscopy is not appropriate. We have recently used the combination of FOS and Glidescope to aid endotracheal intubation in a patient, with supraglottic tumor obliterating the right vocal cord on a pre op nasendoscopic evaluation. In our case we chose awake intubation using the Glidescope as our primary plan but this provided inadequate view of the larynx. We were able to use the view provided by Glidescope to guide fibreoptic scope by a second anaesthetist, through the vocal cords and secured endotracheal intubation safely in the awake patient.
The authors successfully used a Ravussin cannula to achieve rescue oxygenation. Fortunately, they were able to achieve adequate exhalation in the presence of a large upper airway tumour that was already bleeding. In a situation such as this, a patent airway for exhalation cannot be guaranteed and this must be borne in mind when management includes use of a narrow bore cannula crocothyroidotomy for rescuing the airway. Pre induction nasendoscopy is a useful investigation in decision-making, in cases such as that described by the authors. The strategy planned for airway management in this case is not strictly adhered to and a primary awake intubation plan informed by the pre anaesthetic nasendoscopy findings should have been considered. We commend the authors for successfully managing the airway despite difficulties leading to CICV, for highlighting the importance of avoiding repeated instrumentation of the airway when faced with difficulty and concluding that sugammadex is of no help when the nature of obstruction is mechanical.
References:
1. Use of sugammadex in a 'can't intubate, can't ventilate' situation: Br J Anaesth 2012 108(4): 612-14
2. Cook TM, Woodall N, Frerk C. Royal College of Anaesthetists. 4th National Audit Project: Major Complications of Airway Management in the UK. Royal College of Anaesthetists, London, 2011: 153
3.Mort TC: Emergency tracheal intubation: complications associated with repeated laryngoscopic attempts. Anesth Analg 2004; 99: 607-613
4. William R, Ianus AI, Sukhupragarn W, Fickenscher A Sasaki C. Preoperative Endoscopic Airway Examination (PEAE) Provides Superior Airway Information and May Reduce the Use of Unnecessary Awake Intubation. Anesth Analg. 2011 112:602-7
5. Cook TM, Woodall N, Frerk C. Royal College of Anaesthetists. 4th National Audit Project: Major Complications of Airway Management in the UK. Royal College of Anaesthetists, London, 2011: 153
6. Cooper RM. Use of a new videolaryngoscope (GlideScope) in the management of a difficult airway. Can J Anesth. 2003;50(6):611-613.
Conflict of Interest:
None declared
Curtis and colleagues describe airway management for a patient with a large upper airway tumour, discussing the different techniques used and role of rocuronium in this situation. An awake nasal endoscopy in theatre after topical anaesthesia to the nostrils would have been useful in deciding whether awake fibreoptic is a feasible option and more importantly indicated that administering rocuronium is probably unsafe.
It is important to emphasize that in an obstructed airway, gas exchange is poor even if sugammadex is effective in producing rapid and complete reversal of dense neuromuscular blockade.The return of motor power will not resolve an upper airway obstruction caused by a tumour or a mass lesion and this reversal will not be effective in improving oxygenation.
It is also possible that in an unanticipated CICV situation, the steps involved in administering sugammadex might distract the anaesthetist from the main aim of ensuring effective oxygenation and ventilation. The aim should be to recognise an anticipated difficult airway, stick to basic principles of managing it and not have a false sense of security that sugammadex will rescue a failed airway.
Conflict of Interest:
None
Curtis et al report airway management for a patient with an upper airway tumour, describing their escalating responses culminating in a "Cannot-Intubate-Cannot Ventilate" (CICV) situation (more reasonably termed "Cannot-Intubate-Cannot- Oxygenate" [1])
Whilst all scenarios are different, principles are shared. There are elements of complexity, risk, uncertainty and dynamism. Alone, each is important. When they couple, usually in a non-linear way, [2] a situation fraught with danger arises, sometimes called a "combinatorial explosion". Examples of uncertainty in the case described are the reported discrepancy between the findings of nasendoscopy and CT scan and the efficacy of sugammadex for rescue. Examples of coupling include: risk with dynamism; the deterioration of facemask ventilation during the airway management sequence (from "easy" following induction with relaxation to "not possible"), and uncertainty with risk; the use of the inhalational route for provision of anaesthesia, with awareness possible when delivery of vapour is interrupted or failed.
Curtis et al outline their sequence of airway plans in keeping with a key recommendation of the fourth National Audit Project (NAP4), formulation of an airway management strategy [3]. Whilst not explicitly stated by the NAP4 authors, airway management strategies can be classified into reactive, proactive or a combined (a mix of the two). The strategy listed by Curtis et al is essentially reactive, contingent upon a failure of the previous intervention. In a situation where the ability to mitigate for failure is low (such as this case, an airway tumour with conflicting preoperative information), we believe that when interventions are subsequent to a failed technique, the situation (and the patient), is often worsening and dangerous.
We propose that an alternative generic method for strategy formulation using a proactive principle could be helpful. A common feature of a proactive approach are the initial interventions are done for an awake patient, building-in safety before committing to general anaesthesia, a form of "insurance policy".
For this case, one or more proactive approaches could include:
1 insertion of a prophylactic cricothyroid cannula under local anaesthesia [4].
2 an "awake-look" following topical local anaesthesia or sedation [5]. This approach is the mainstay for flexible fibreoptic techniques but can be successfully applied for other airway devices, such as videolaryngoscopes [6].
3 an awake retrograde technique [7].
As mentioned, proactive approaches may be combined with reactive responses. For instance, insertion of a precautionary cricothyroid cannula may be followed by induction of general anaesthesia. Should the cricothyroid cannula fail during problematic airway management, subsequent reactive responses are needed. The potential for a complication such as this (and others) should be considered.
Proactive approaches may be more suitable when the magnitude of one or more of the four elements, complexity, risk, uncertainty and dynamism, or "CRUD" for short, are predicted or expected to summate dangerously.
References
1Hamaekers AE, Henderson JJ. Equipment and strategies for emergency tracheal access in the adult patient. Anaesthesia 2011; 66(Suppl 2), 65- 80.
2 Gaba DM, Maxwell M, DeAnda A. Breaking the chain of accident evolution. Anesthesiology 1987; 66: 670-6.
3 Royal College of Anaesthetists, Difficult Airway Society. Major complications of airway management in the UK: results of the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society March 2011. Report and Findings. Royal College of Anaesthetists, London, 2011. http://www.rcoa.ac.uk/index.asp?PageID=1089 (accessed 10 April 2012)
4 Gerig HJ, Schnider T, Heidegger T. Prophylactic percutaneous transtracheal catheterisation in the management of patients with anticipated difficult airways: a case series. Anaesthesia 2005; 60: 811-5.
5 Johnson KB, Swensen JD, Egan TD, Jarrett R, Johnson M. Midazolam and remifentanil for intensely stimulating procedures of brief duration: experience with awake intubation. Anesth Analg 2002; 94: 1241-3.
6 McGuire BE. Use of the McGrath video laryngoscope in awake patients, Anaesthesia 2009; 64: 912-4.
7 Dhara SS. Retrograde tracheal intubation. Anaesthesia 2009; 64: 1094-1104.
Conflict of Interest:
None declared
Editor-We read with interest the case report by Curtis and colleagues1 on the use of sugammadex in a can't intubate, can't ventilate (CICV) scenario. They state that the case highlights that rapid reversal of neuromuscular block with sugammadex will not relieve necessarily airway obstruction caused by the instrumentation of a compromised airway and that it is not a substitute for emergency tracheal access. Whilst we can only agree with this statement we feel that the message of the report is misleading because we believe that they simply chose the wrong strategy for securing the patient's airway. Applying this inappropriate strategy then led to the total mechanical obstruction of her airway thus creating the CICV situation. There is therefore no wonder that the subsequent use of sugammadex, although returning patient's spontaneous respiration, did not restore airway patency. Is this not what one would expect in a situation like this? Is evidence needed for the use of common sense?
It appears that they may have mistaken planning for an anticipated difficult intubation (which has not yet happened) for dealing with an unanticipated difficult intubation (an emergency which has already occurred). They wasted the advantage of anticipating difficult intubation and turned from 'how to avoid it' into just simply 'how to deal with it'. Their 'stepwise plan' was basically to follow the Difficult Airway Society (DAS) guideline for the management of an unanticipated difficult intubation2 i.e. direct laryngoscopy as initial plan, secondary plan with an alternative blade, videolaryngoscope or fibrescope, tertiary plan to wake the patient up reversing the rocuronium with sugammadex and in the case of CICV to perform a cricothyroid puncture. However the authors of the DAS guideline explicitly state that this guideline is for a patient without upper aiway obtruction. For an anticipated difficult intubation Curtis and colleagues chose to follow the unanticipated difficult intubation algorithm which is not planning but on the contrary, a total failure to plan.
As summarised in the classic paper by Mason and Fielder3 based on both their experience and data from NCEPOD, there are only 2 options for a patient with upper airway obstruction i.e. for a patient like that of Curtis and colleagues. If the intubation is deemed possible then such a patient should have inhalational induction (Plan A) in theatre with rigid bronchoscopy and emergency tracheostomy instantly available as a Plan B. If the intubation is considered impossible then the patient needs an awake tracheostomy. The alternate approach of using an awake fibreoptic approach is also advocated by experts in fibreoptics.5 Nevertheless, it is unwise to paralyse such a patient before the airway is secure. This misjudgment may be coming from Curtis and colleagues' misunderstanding of the situation where their plan appears, as they state, to 'secure tracheal intubation', rather than to secure the airway as should have been the aim.
In addition to choosing a wrong technique for their patient, their management of initial Grade IV laryngoscopy by repeating it twice more with different blades is also of concern as this technique had been previously flagged up as hazardous. They rightly mention that the reports from NAP4 in 20114 found that 'problems arose when difficult intubation was managed by multiple repeat attempts at intubation. The airway problem regularly deteriorated to a 'can't intubate can't ventilate' situation (CICV). It is well recognised a change of approach is required rather than repeated use of a technique that has already failed.' This finding however was not new as it only confirmed what was known more than a decade earlier from the data of NCEPOD in 1998 that 'if a decision is made to intubate a patient with upper airway obstruction, a maximum of 2 attempts must be made as persistent attempts at tracheal intubation may result in total obstruction'.3
To summarise, it would be sensible, as also Curtis and colleagues conclude, with patients such as this an awake nasendoscopy is a useful component of airway assessment in confirming the ease of access to the airway in an awake patient. This does not mean that the airway can be accessed in the anaesthetised patient, but does enable the awake option to be considered and is the senior author's preference for managing patients such as this.
B Telgarsky, ST5 Anaesthetics M Stacey, Consultant Anaesthetist University Hospital of Wales, Cardiff
1 Curtis R, Lomax S and Patel B. Use of sugammadex in a 'can't intubate, can't ventilate' situation. Br J Anaesth 2012; 108: 612-614. 2 Henderson JJ, Popat MT, Latto IP, Pearce AC. Difficult Airway Society guidelines for the management of the unanticipated difficult intubation. Anaesthesia 2004;59:675-94. 3 Mason RA, Fielder CP. The obstructed airway in head and neck surgery. Anaesthesia 1999; 54: 625-8. 4 Royal College of Anaesthetists. Major complications of airway management in the UK. The Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society, London, 2011. 5. Heidegger T. Fiberoptic intubation. N Engl J Med 2011;364(20): e42.
Conflict of Interest:
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I read with interest the case of CICV situation, which largely I think is iatrogenic and even in this 2012 I wonder the lack of low thershold to use fibre optic intubation. I would also like warn that the author might give out a wrong message of false sense of security by the presence of sugammadex. The patient was very lucky to be alive in this case rather than the wonder of sugammadex.
Conflict of Interest:
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The recent Case Report by Curtis et al. on the use of sugammadex in a "can't intubate, can't ventilate" (CICV) situation was illustrative of some old but still true axioms. 1) If one is sufficiently concerned about the status of a patient's airway that pre-anesthetic preparations include making sure that a Ravussin needle and Manujet as well as sugammadex 16 mg kg-1 are immediately available in the operating suite, then awake tracheal intubation is surely the safest approach to securing a patent airway. 2) One should be wary of converting a "can't intubate but can ventilate" situation into a CICV scenario by multiple attempts at direct laryngoscopy.
However, this report also demonstrates a potential hazard that the authors do not comment on. They noted that "...60 seconds [after sugammadex administration] spontaneous chest wall movement was observed with the patient beginning to make respiratory effort and moving her upper limbs. Train-of-four nerve stimulation showed no evidence of fade. An obstructed pattern of breathing was witnessed with no capnography trace or movement of the reservoir bag." The authors have described a classic setup for the onset of negative pressure induced pulmonary edema. It must be concluded that attempted "rescue reversal" of rocuronium or vecuronium with sugammadex in the absence of a patent airway is not risk free.
Conflict of Interest:
None declared