Laryngospasm Complicating Awake Nasal Intubation in Ludwig's Angina

Laryngeal Mask Airway Facilitates Awake Fiberoptic Intubation in a Patient with Severe Oropharyngeal Bleeding

Laryngeal mask airway facilitates awake fiberoptic intubation in a patient with severe oropharyngeal bleeding.

Management of failed intubation in a septic parturient

For anesthesiologists, it is inevitable to confront with various difficult conditions during mask ventilation and intubation. Therefore, anesthesiologists perform a variety of airway examinations and history taking to anticipate and to overcome demanding situations. Yet, the parameters obtained from such measurements are not satisfactory. In patients having the conditions that indicate difficult intubation, awake intubation is performed especially when the plausibility of mask ventilation is uncertain. Awake fiberoptic intubation has been adopted for management of anticipated difficult tracheal intubation. However, fiberoptic bronchoscope requires higher cost and longer time to learn the technique. Recently, laryngoscope or stylet with video system is used in various situations, including difficult intubation. Also, in awake intubation, some cases with video-assisted laryngoscope have been reported. Successful awake video-assisted laryngoscopic intubation has been performed in patients with limited neck extention and Mallampati grade 4 [1]. Also, Park et al. [2] reported a case of a patient with restricted mouth opening, nearly fixed neck movement and regressed mandible due to scar contracture where intubation was performed with the use of fiberoptic bronchoscopy under GlideScope® video laryngoscope guidance. Recently, Rosenstock reported that in 93 patients with an anticipated difficult intubation, there is no difference in patients' discomfort, ease of the technique and intubation success rate on the first attempt between the awake video-assisted laryngoscopic intubation and awake fiberoptic intubation [3]. Case reports with awake intubation using video-assisted intubating stylet are still rare. There is a case report that reported successful awake intubation with video-assisted intubating stylet in a patient with fixed neck due to halo vest and limited mouth opening (3 cm), in addition to modified Mallampati score grade 4 [4]. Smaller diameter of video-assisted intubating stylet can be applied to patients with more limited mouth opening or loose tooth than video-assisted laryngoscope. Video-assisted intubating stylet provided faster and easier intubations than the video-assisted laryngoscope in patients with limited neck motion [5]. In oral, laryngeal, glottic, supraglottic cancer, cancer bleeding during intubation procedure often interfere with the laryngoscopic view. In such situation, owing to smaller volume than video laryngoscope, the video-assisted intubating stylet is helpful to avoid injuring the mass and to overcome potentially traumatic airway manipulation. Patient preparation for awake intubation with video-assisted laryngoscope or intubating stylet is same as the preparation of awake fiberoptic intubation: antisialogue, oxygen supplement, topical application and transtracheal injection of local anesthetics. For adequate sedation and analgesia, combination of short acting opioids (eg. remifentanil) and sedatives (eg. propofol, or midazolam) infusion can be administered intravenously. Video-assisted laryngoscope or video-assisted stylet has an external monitor, and the supervisor can see the anatomy together and educate intubation skills on a case-by-case basis. With sufficient training of stylet usage, the quick and easy to use new instrument, such as video-assisted stylet, is expected to be selected as an alternative awake intubating device instead of the flexible fiberscope that requires longer time to learn. However, the currently used video-assisted laryngoscope and intubating stylet do not have the suction function. Therefore, preparations to prevent oral secretion are more important, and the assistant should help the oral suction of secretion or bleeding. In this respect, it is required to develop video-assisted laryngoscope or intubating stylet with the suction function in the near future.

Background: Fiber optic intubation has become an integral part in management of anticipated difficult airways. Various anesthetic drugs have been used to assist awake fiber optic intubation (AFOI) for producing conscious sedation to provide a calm, cooperative, and responsive patient without respiratory depression for successful awake fibre optic intubation. Aims and Objectives: The aim of the present study was to compare the efficacy of dexmedetomidine and magnesium sulfate during awake fiber optic orotracheal intubation in patients scheduled for cervical spine surgeries. Materials and Methods: A randomized, prospective, and comparative study design was conducted in 60 patients in JAH group of hospitals. All patients were randomly divided into two groups: Group A (n=30) patients received dexmedetomidine (1 μg/kg) and Group B (n=30) patients received magnesium sulfate (40 mg/kg) in 100 ml normal saline over 10 min. The fiber optic orotracheal intubation was performed and primary outcome was level of sedation assessed using Ramsay sedation score. Other parameters of study included cough score and intubation score to compare intubating conditions. The secondary outcomes of study included variations in hemodynamic parameters heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and SPO2 during drug infusion at 2-min interval, immediately after intubation and every 10 min after intubation till 30 min. Results: Group A (Dexmedetomidine) had better sedation score, cough score, and intubation score with stable hemodynamic variables than Group B (Magnesium Sulphate) with statistically significant results. Conclusion: Patients receiving dexmedetomidine had better sedation providing more optimum conditions for AFOI with stable hemodynamic parameters and lesser adverse effects during the procedure than magnesium sulfate.

Optimal airway topicalisation is the key to successful and smooth awake intubation in anticipated difficult airway. Dexmedetomidine nebulisation has been used effectively as premedication and could be a useful adjunct to lidocaine for awake fiberoptic intubation (AFOI). This study evaluated the efficacy of dexmedetomidine-lidocaine nebulisation for AFOI.To compare the efficacy of Dexmedetomidine with lignocaine versus Plain Lignocaine nebulization to achieve successful airway placement for awake fiberoptic intubation (AFOI). To assess the degree of patient comfort during the procedure on basis of cough score, gaging reflex score, intubating conditions, vocal cord position, patient behaviour and to assess the hemodynamic stability and the time taken for AFOI. 96 adult patients, ASA grades I-III with anticipated difficult intubation requiring AFOI for elective surgery were enrolled. Patients received nebulisation with dexmedetomidine 1mcg/kg + 4ml of 4% lidocaine (Group A, n=48) & 4ml of 4% plain lidocaine (Group B, n=48). Outcomes were assessed by an independent observer. Primary outcome of cough and gag reflex was assessed on basis of four-point intubation condition assessment score. Secondary outcomes assessed were patient comfort using five-point intubation comfort scale, three-point behaviour scale, hemodynamic stability, additional sedation, lidocaine aliquots, intubation attempts and complications. Fischer exact test was used for categorical variables and Mann -Whitney / independent student t-test for continuous variables.P values < 0.05 was considered statistically significant.: Both groups displayed similar demographic profiles. While all patients were successfully intubated, Group A exhibited better intubating condition grades (p<0.001) and lower cough scores compared to Group B (p<0.001). Patient comfort (p<0.001) and hemodynamic stability (p<0.05) was better in Group A. Only 3 patients in Group A required additional sedation compared with 19 patients in Group B (p<0.001). This study demonstrated superior efficacy of dexmedetomidine- lidocaine nebulisation in providing optimal intubating conditions for AFOI.

Video Review

To the Editor: We read with great interest the case report published in Chinese Medical Journal by Ma et al.,[1] who described difficult airway for patients undergoing spine surgeries. We believe that there are several issues regarding the difficult airway concepts and difficult airway management algorithm used in this article that need to be clarified. First, all three cases reported in this article were anticipated as difficult airways due to cervical stiffness and/or restricted mouth opening, but general anesthesia was induced, and muscle relaxant was administered before tracheal intubation. We were interested in knowing whether the authors checked the ability to ventilate the patient by facemask before anesthesia induction and administration of muscle relaxant. It must be emphasized that when airway management is expected to be difficult, either because of the presence of a pathologic factor or a combination of anatomic factors, airway patency should be secured and guaranteed (usually by intubation) while the patient remains awake. In clinical practice, awake intubation is often regarded as the safest option for patients with known or anticipated difficult airway and the awake fiber-optic intubation has been established as the gold standard for difficult airway management.[2] In the recent fourth National Audit Project Report of the Royal College of Anaesthetists in the United Kingdom,[3] provider judgment against performing awake fiber-optic intubation has been cited as a potential contributing factor in poor airway outcomes. Moreover, if provider plans to manage the difficult airway under anesthesia, spontaneous breathing must be reserved before successful intubation and the patient's airway should be tested by gradually deepening anesthetic depth. Especially, it is necessary to check the ability to ventilate the patient by facemask before administering a muscle relaxant. When facemask ventilation is not difficult, the airway is easy to manage using the facemask ventilation even if the larynx proves difficult to visualize or tracheal intubation is a failure.[4] Second, in the second case, facemask ventilation was easy, direct laryngoscopy was not attempted, and tracheal intubation was achieved with McGrath video laryngoscope at first attempt. According to the latest standards of difficult airways by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway,[5] this case should not be defined as a difficult airway. Third, in the third case, the GlideScope video laryngoscope was used as the first choice for tracheal intubation after anesthesia induction and revealed a Cormack–Lehane Grade 4 laryngeal view. The readers were not provided with the blade type and size of GlideScope video laryngoscope used in this case. There are totally two reusable and three disposable adult blades of GlideScope video laryngoscope available, and the proper function of a blade is dependent on using an appropriate length of the blade. Fourth, in the third case, the “cannot intubate, cannot ventilate” (CICV) situation, which is one of the most critical emergencies in clinical anesthesia,[6] occurred after anesthesia induction. After the video laryngoscopic intubation failed, three fiber-optic intubation attempts were performed via oral or nasal route. The fiber-optic intubation was finally successful, but arterial oxygen saturation dropped to the lowest level of 76%. We argue that, in managing this CICV patient, the authors did not obey the algorithm of living difficult airway management guideline and had placed the patient at a risk of loss of the airway control. According to the CICV algorithm of the American Society of Anesthesiologists’ difficult airway management, early insertion of a supraglottic airway device, as long as mouth opening is sufficient, is standard practice for managing a CICV situation.[5] The supraglottic airway devices have been effective in many CICV cases. Furthermore, they can provide an intubation conduit using a blind technique and by lightwand, optical stylet, or fiber-optic guidance during airway resuscitation.[7] If the supraglottic airway device fails to provide adequate gas exchange for a CICV patient, the option of emergency invasive airway access including transtracheal jet ventilation and surgical airway should be immediately performed.[5,6] As the clinicians, we must remember that maintenance of oxygenation and ventilation is paramount during difficult airway management. When the intubation attempt fails in a patient with difficult facemask ventilation; thus, the priority is to ensure adequate ventilation and oxygenation of the patients rather than repeated intubation attempts.[4,5] Actually, patients with difficult airways may only die of ventilation or oxygenation failure, but do not die of failed intubation.[6] Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Awake fibreoptic intubation skills in obstetric patients: a survey of anaesthetists in the Oxford region

Aims of Study:To evaluate the efficacy, hemodynamic changes, and patient comfort during awake fiberoptic intubation done under combined regional blocks.Materials and Methods:In the present observational study, 50 patients of American Society of Anesthesiologists ( ASA) Grade I–II, Mallampati Grade I–IV were given nerve blocks - bilateral glossopharyngeal nerve block, bilateral superior laryngeal nerve block, and recurrent laryngeal nerve block before awake fiberoptic intubation using 2% lidocaine.Results:Procedure was associated with minimal increases in hemodynamic parameters during the procedure and until 3 min after it. Most of the intubations were being carried out within 3 min. Patient comfort was satisfactory with 90% of patients having favorable grades.Discussion:The most common cause of mortality and serious morbidity due to anesthesia is from airway problems. One-third of all anesthetic deaths are due to failure to intubate and ventilate. Awake flexible fiberoptic intubation under local anesthesia is now an accepted technique for managing such situations. In awake patient's anatomy, muscle tone, airway protection, and ventilation are preserved, but it is essential to sufficiently anesthetize the upper airway before the performance of awake fiberoptic bronchoscope-guided intubation to ensure patient comfort and cooperation for which in our study we used the nerve block technique.Conclusion:A properly performed technique of awake fiberoptic intubation done under combined regional nerve blocks provides good intubating conditions, patient comfort and safety and results in minimal hemodynamic changes.

We appreciate Prof. Xue et al. for their thoughtful comments on our study.[1] We agree with them that history of smoking and respiratory comorbidities can increase airway reactivity to airway irritation, resulting in an increased severity of cough. In our study, patients with a history of smoking and respiratory comorbidities were excluded and the demographic data of patients were comparable between the groups. Furthermore, two senior anesthetists actualizing our study had equal proficiency with the use of fiberoscope and had performed more than 50 fiberoptic intubation for difficult airway management before this study. To ensure the consistency and repeatability of measurements, the procedure of awake fiberoptic nasotracheal intubation was normalized by video training and the test tools were illustrated for all participants before the study. In addition, we know that both patient's head position and airway clearance procedure can affect ease of fiberoscopy and tracheal tube placement. In our study, the patient's head was placed in the sniffing position with a 6 cm-high firm pillow under the occiput and the jaw-thrust was performed for the airway clearance. As to the airway topical anesthesia, we completely agree with Xue et al. that a reasonable waiting period after each lidocaine spray helps ensure topical anesthetic to go into effect and reach peak effect, but spray of lidocaine via the working channel of fiberoscope often does not cover the whole supraglottic and glottic areas, and maybe only covers a small airway area. Therefore, even the contact time of lidocaine with the airway mucosa is enough, it may also not meet the requirement to pass fiberoscope and tracheal tube, as shown in the previous studies.[23] In the previous study by Xue et al.,[2] 61.5–73.1% of patients displayed grimacing and coughing responses during awake fiberoptic orotracheal intubation, though the patients received the classic “spray-as-you-go” technique under midazolam and fentanyl sedation. Jiang et al.[3] also showed that the incidence of coughing was 43.3% in patients receiving the glottis topical anesthesia with pressure-driven 2% lidocaine spray 3 times for 20 s each time at a 30-s interval. Despite a short interval of lidocaine spray used in our study did not ensure topical anesthesia to reach peak effect, grimacing, and coughing mainly occurred during advancement of fiberoscope and tracheal tube into the trachea, and most patients only exhibited slight grimacing and coughing, which met the requirements of comfort and adequate cooperation for awake fiberoptic intubation (AFOI). We are very sorry not to define clearly intubation score, a multiple-factor variable including the ease of AFOI, scores of patient reaction and coughing during AFOI.[2] In our study, power analysis of sample size was actually performed according to patients’ reaction scores, rather than intubation score. Finally, in available literature, a loading dose of dexmedetomidine ranging from 0.4 to 1.5 μg/kg has been used for sedation combined with or without midazolam for AFOI. However, there is not information regarding hypnotic synergism of dexmedetomidine and midazolam when using them together. A possibility shown by Cattano et al.,[4] a given dose of dexmedetomidine 0.4 μg/kg combined a dose of midazolam 2 mg did not produce sufficiently sedation. In our experience, dexmedetomidine 1 μg/kg combined with midazolam 2 mg can cause deep sedation, which may place patients at a risk of airway uncontrol. Moreover, we completely agree with Xue et al. that prolonged preparation time for targeted sedation level may challenge a patient's patience and comfort. Unfortunately, the time required for targeted sedation level was not measured in our study. This is a limitation of our study design.

Awake fiberoptic intubation with double lumen tube for severe predicted difficult airways: Could it be feasible with a rigid fiberoptic stylet?

We read the case report by Sulaiman and Charters [1] with interest and would like to make a few comments. To justify their decision to use awake fibreoptic intubation, they claim that the patient was at risk of being in a ‘can’t intubate, can't ventilate' situation. However, the information they give is insufficient to justify such a conclusion. The patient was conscious and extremely co-operative. He was spitting blood but was haemodynamically stable. Airway assessment showed him to have a short bull neck but the external appearance was unchanged. No comment is made about mouth opening, although it was obviously adequate to allow inspection of the oral cavity. Also, they have omitted the information about the airway management and grade of laryngoscopy during the first anaesthetic, which has to be taken into account. Any patient with oropharyngeal haemorrhage is unlikely to be a good candidate for fibreoptic intubation due to the possibility of blood obscuring the view. The use of a local anaesthetic can start or increase bleeding by causing coughing and straining, as illustrated by this case. Furthermore, the local anaesthetic is unlikely to be effective in the presence of blood. If there was a risk of ‘can’t intubate, can't ventilate', then the safest option would have been a tracheostomy under local anaesthetic, which a conscious and co-operative patient would have tolerated. The use of topical anaesthesia is not completely free from side-effects. It is not uncommon to see a patient cough or strain following the administration of local anaesthetic spray or drops into the nostrils or oropharynx. We had a patient with Ludwig's angina who was severely dyspnoeic and was planned for an awake fibreoptic intubation. Following the use of local anaesthetic spray into the oropharynx he had a bout of feeble coughing and then developed complete airway obstruction. His oxygen saturation dropped to less than 90%. Fortunately, fibreoptic intubation was then successfully performed without delay, preventing further deterioration. Perhaps in cases such as these, nebulised lidocaine might be a safer option. During the last 10 years, the use of awake fibreoptic intubation has increased considerably. It is a relatively easy skill to learn and makes an anticipated difficult intubation scenario safer than before. It is possible that because of its availability, trainees are deciding to perform awake intubation in patients with only a small risk of difficulty. It may be that the trainees are missing out on doing a thorough pre-operative assessment of the airway and also depriving themselves of the mastering another very valuable skill – performing a difficult intubation under direct laryngoscopy. In a patient with a known or anticipated compromised airway the management plan must take into consideration the history of previous anaesthetics. It is true that this patient's anatomy will have been considerably altered by the surgery, but a history of previous straightforward direct laryngoscopy may have resulted in this option being included in the contingency planning at an earlier stage in the case.

Awake fiberoptic intubation requires adequate airway anaesthesia along with good sedation to achieve patient cooperation during intubation without respiratory depression and hypoxia.The purpose of this study was to compare dexmedetomidine alone and dexmedetomidine with ketamine in order to achieve an ideal regimen during awake fiberoptic intubation by providing sedation, good intubating conditions, better hemodynamic stability, and patient satisfaction.This prospective, randomised, double-blind clinical trial included 60 patients who were scheduled for elective surgery under general anaesthetic and required nasotracheal intubation. Patients were randomly assigned to two groups of 30 each, with ages ranging from 18 to 65 years and ASA grades I and II. All patients received an inj. dexmedetomidine bolus at 1 mcg/kg over 10 min. followed by a study drug depending on the group. In Group A, patients will receive an inj. ketamine 15 mg bolus and a 20 mg/hr ketamine infusion, whereas those in Group B will receive a normal saline bolus and infusion till completion of intubation. Sedation by Ramsay sedation scale (RSS), intubation response (by coughing score and grimace score), hemodynamic stability was observed during awake fiberoptic intubation, and patients' satisfaction by visual analogue score (VAS) and recall of events were assessed post operatively at 24 hours. In Group A with greater hemodynamic stability compared to Group B, RSS and Post-Operative Vas Score were more successfully attained. A combination of dexmedetomidine and ketamine provides the optimum sedation, hemodynamic stability, and patient satisfaction during awake fiberoptic intubation.

Comparison of patients’ experience following awake and asleep fibreoptic intubation: A prospective observational study