Laryngeal Airway Research Articles

Airway Management in Pediatric Head and Neck Infections

Infectious diseases of the head and neck in children are very common but may sometimes cause upper airway obstruction. Various degrees of respiratory distress are possible, but one will be extra-cautious with newborns and neonates, because the clinical features can evolve especially fast in young children. A child with a respiratory compromise should never be left unattended. Nasal, pharyngeal, and laryngeal airways can be involved and require specific management. Each time the airway of a child may be compromised, the pediatrician and otolaryngologist have to be prepared for the worst-case scenario: anticipation is essential and allows avoidance of serious troubles.

A randomised comparison of the self‐pressurised air‐QTM intubating laryngeal airway with the LMA UniqueTM in children*

We conducted a randomised trial comparing the self-pressurised air-Q™ intubating laryngeal airway (air-Q SP) with the LMA-Unique in 60 children undergoing surgery. Outcomes measured were airway leak pressure, ease and time for insertion, fibreoptic examination, incidence of gastric insufflation and complications. Median (IQR [range]) time to successful device placement was faster with the air-Q SP (12 (10-15 [5-18])) s than with the LMA-Unique (14 (12-17 [6-22]) s; p=0.05). There were no statistically significant differences between the air-Q SP and LMA-Unique in initial airway leak pressures (16 (14-18 [10-29]) compared with 18 (15-20 [10-30]) cmH2 O, p=0.12), an airway leak pressures at 10 min (19 (16-22 [12-30]) compared with 20 (16-22 [10-30]) cmH2 O, p=0.81); fibreoptic position, incidence of gastric insufflation, or complications. Both devices provided effective ventilation without the need for airway manipulation. The air-Q SP is an alternative to the LMA-Unique should the clinician prefer a device not requiring cuff monitoring during anaesthesia.

Comparison of the air-Q ILA™ and the LMA-Fastrach™ in airway management during general anaesthesia

AbstractOne hundred and sixty patients aged between 20–60 years with ASA physical status I-II, undergoing elective surgery under general anaesthesia, were enrolled into this prospective, randomised, double-blinded study to compare the success rate of tracheal intubation between the air-Q™ intubating laryngeal airway (ILA) and the laryngeal mask airway (LMA)-Fastrach™ (80 patients in each group). The degree of mouth opening, occurrence of coughing, laryngospasm, ease of insertion, adequacy of ventilation, and number of attempts were recorded during the insertion of the air-Q™ ILA and the LMA-Fastrach™. Tracheal intubation via the supraglottic airway devices was then performed, and cricoid manipulation, ease of insertion and number of attempts, were noted. Postoperatively, the degree to which patients had a sore throat using visual analogue scale (VAS), hoarseness of voice and blood on the air-Q™ ILA and the LMA-Fastrach™ were recorded. In terms of ease of insertion, there was no statistically significant d...

Evaluation of three adjusting manoeuvres and type of endotracheal tube in the success of air-Q™ aided tracheal intubation

Background: The present study observed whether the use of three different adjusting manoeuvres and use of an armoured tracheal tube would increase the success rate of tracheal intubation, aided by the air-Q™ intubating laryngeal airway (air-Q ™ ILA). Method: Fifty American Society of Anesthesiologists (ASA) I and II patients undergoing elective surgical procedures were randomly assigned to two groups. In the endotracheal tube (ETT) group, standard ETT was used, while in the armoured ETT (AETT) group, tracheal intubation was performed using AETT. After a uniform premedication, induction and relaxation technique, an appropriate sized air-Q ™ ILA with ETT in-situ, was placed. After good ventilation, a flexible fibrescope was passed down the ETT, and the percentage of glottic opening (POGO) was documented. Subsequently, three adjusting manoeuvres were applied in sequence. These included firstly, backward pressure over the larynx; secondly, head extension; and lastly, neck flexion. After noting the POGO score with each adjusting manoeuvre, the incidence of successful intubation was noted, with and without manoeuvres. Results: The best POGO score (84%) was observed with the application of backward pressure. Successful tracheal intubation was achieved in 56-60% of patients without the use of any manoeuvres, using either type of tracheal tube. For the rest, tracheal intubation was achieved using backward pressure, except in one patient from the ETT group. The incidence of successful tracheal intubation was nearly identical with either type of ETT. Conclusion: Successful tracheal intubation can be achieved in 96% of cases using adjusting manoeuvres. The nature of the tracheal tubes did not influence the success rate.

The air‐Q® intubating laryngeal airway for endotracheal intubation in children with difficult airway: our experience

The air‐Q^® intubating laryngeal airway for endotracheal intubation in children with difficult airway: our experience

Air-Q the Intubating Laryngeal Airway: Comparative study of hemodynamic stress responses to tracheal intubation via Air-Q and direct laryngoscopy

Background: Tracheal intubation is the gold standard for securing airway. Tracheal intubation through DLS produces marked hemodynamic stress responses. The Air-Q is a new supraglottic airway device. The purpose of this study was to determine whether endotracheal intubation through Air-Q is associated with lesser hemodynamic stress responses.Methods: 60 patients scheduled for elective surgery under general anesthesia requiring endotracheal intubation were randomly assigned into two groups. Direct laryngoscopy group and Air-Q group. Blood pressure and heart rate were recorded before, after induction, immediately after intubation and every minute for 4 min after intubation. The intubation time was recorded. Upon removal of the Air-Q, trauma to the upper airway was reported.Results: The intubation time was shorter in the DLS group compared with the Air-Q group (P value < 0.05). A significant reduction in BP was evident after the induction of anesthesia in both groups. Immediately after intubation, there was a significant increase in BP compared with the preintubation values. A decline was inspected between 1 and 4 min postintubation in both groups with significant difference immediately, at 1 and 2 min postintubation between the two groups. There were significant increase in HR immediately, at 1 and 2 min postintubation compared with the preintubation values, but there was no significant difference at each time point between two groups. Sore throat was more in the Air-Q group (P value <0.05).Conclusion: The hemodynamic stress response to intubation by Air-Q is less than that of DLS despite the longer duration of the former.

The air-Q as a conduit for fiberoptic aided tracheal intubation in adult patients undergoing cervical spine fixation: A prospective randomized study

The air-Q™ intubating laryngeal airway is a supraglottic airway device which was designed to allow adequate patient ventilation and reliable blind endotracheal tube intubation.ObjectivesTo investigate the efficacy of air-Q as a conduit for fiberoptic endotracheal intubation in adult patients with limited cervical spine mobility compared with fiberoptic-guided intubation alone.DesignProspective randomized study.PatientsSixty adult (12 female) patients, ASA physical status I and II scheduled for cervical spine fixation under general anesthesia. Patients were randomized into two parallel groups. Exclusion criteria includes, history of difficult airway, mouth opening <3 cm, Mallampati class ⩾III and, increased risk of aspiration of gastric contents.InterventionIn the first group, endotracheal intubation was aided with the fiberoptic scope while patients in the second group were intubated with the fiberoptic scope guided with the air-Q as a conduit. The number of attempts and time to successful insertion of air-Q and endotracheal tube were recorded. The fiberoptic quality of the vocal cords view as seen through the air-Q and ease of endotracheal tube insertion were also assessed.ResultsThe air-Q was easily inserted in all patients of the second group with mean insertion time (22.6 ± 4.3 s). The air-Q provided a good fiberoptic view of the vocal cords and successful tracheal intubation in 29 (96.7%) patients of the second group on the first attempt. Time to tracheal intubation in the second group was significantly shorter than the first group (21.6 ± 5.7 and 29.8 ± 6.2 s respectively). The air-Q was easily removed without any complications.ConclusionsThe air-Q as a conduit for fiberoptic scope provided a better view of the vocal cords and, less insertion time of the endotracheal compared to fiberoptic-aided endotracheal intubation in adult patients with limited cervical spine mobility scheduled for cervical spine fixation.

Clinical application of laryngeal tube-suction airway

Background Laryngeal tube-suction airway(LTSA) is the second generation of Laryngeal tube airway,has been gradually applied in clinical due to its advantage of easy operation,less damage to the respiratory tract,less irritation,easier tolerance,and fewer complications,and application for both positive pressure ventilation and spontaneous respiration. Objective According to the studies of clinical application of LTSA,to compare the pros and cons of LTSA with other artificial airway,explore reasonable application and management of LTSA. Content Reviews on the structural characteristics,placement methods,postplacement management,removal methods,indications,contraindications and complications of LTSA. Trend According to the clinical application,choose LTSA reasonablly,further explore its structural characteristics,placement methods,post-placement management, removal methods, indications, contraindications and complications, to lead to safer and more effective clinical applications in future. Key words: Laryngeal tube-suction airway; Respiratory tract; Artificial airway; Anesthesia

Treatment of laryngeal hyperfunction with flow phonation: A pilot study

Context: While clinical successes and descriptions have been reported in a few texts, no data exist to define the utility of flow phonation to improve voice quality in patients with laryngeal hyperfunction. Aims: To provide pilot data regarding the utility of three exercises (gargling, cup bubble blowing, and stretch-and-flow) to improve phonatory airflow during voicing in patients with laryngeal hyperfunction. Settings and Design: Outpatient Voice and Swallowing Center in a University Medical Center. Materials and Methods: Participants received five treatment sessions and were evaluated prior to treatment and after each session using a Phonatory Aerodynamic System to measure airflow during voicing tasks. Noise-to-harmonic ratio and perceptual voice measures were also obtained, as was self-perception of voice handicap. Statistical Analysis Used: Repeated All increased airflow and decreased laryngeal airway resistance over five sessions. Measures Analysis of Variance. Results: Six participants completed the protocol. All participants decreased self-perception of voice handicap and improved on noise-to-harmonic ratio and perceptual ratings of vocal quality. Conclusions: Data derived on a small sample of patients in an exploratory investigation suggest further research into the use of these three exercises to improve airflow with voicing and improve vocal quality in patients with laryngeal hyperfunction is warranted.

Validation of the unassisted, gum-elastic bougie-guided, laryngeal mask airway-ProSeal™ placement technique in anaesthetized patients

Aims:The laryngeal mask airway-ProSeal™ can be inserted digitally, by introducer tool, or by railroading it over a bougie placed first in the patient's oesophagus, which is highly successful, but as originally described, requires an assistant. An unassisted bougie-guided placement technique has also been described, but no data on its effectiveness have been reported.Methods:We reviewed data collected during a randomized, controlled trial comparing the air-Q® Intubating Laryngeal Airway and LMA-Proseal™, in which all LMA-Proseal™ devices were inserted using the unassisted (one-operator), bougie-guided placement technique.Results:Forty-eight devices were placed. All devices were placed successfully. Successful placement was achieved in 47 (98%) patients on first attempt and in one (2%) patient on the third attempt. Mean (SD) time required for insertion establishing ventilation was 28 (11) s. Mean (SD) airway seal pressure was 30 (6) cmH2O. Gross blood was found on four (8%) devices upon removal, but no oropharyngeal injuries were noted on oral exam in the recovery unit prior to discharge. The most common complaints in recovery and 24 h post-operatively were sore throat [discharge: mild = 18/48 (38%); 24 h: mild = 9/38 (19%), moderate = 1/38 (3%)] and pain on swallowing [discharge: mild = 7/48 (15%); 24 h: mild = 2/38 (6%)].Conclusions:Our data confirm that in experienced hands, bougie-guided placement of the LMA-Proseal™ without the aid of an assistant can be accomplished quickly and successfully without affecting the expected clinical performance of the device.

An Uncommon Cause of Stridor

An adult male patient presented to an Accident and Emergency Department with stridor, and was diagnosed clinically to have infective exacerbation of chronic obstructive pulmonary disease. A CT scan of his neck revealed a large mass occluding the laryngeal airway. A biopsy and subsequent histopathological analysis of this mass revealed no evidence of a malignancy. Despite this, a laryngectomy was undertaken and a large verrucous squamous cell carcinoma was confirmed.

The effects of cigarette smoking on the female voice

To investigate voice changes as they develop over time due to cigarette smoking, women who never smoked (NS), women who smoked less than 10 years (S1), and women who smoked 10 or more years (S2) were compared. Acoustic (fundamental frequency, jitter, shimmer, signal-to-noise ratio), electroglottographic (open, closing, and speed quotients), aerodynamic (subglottal pressure, airflow, laryngeal airway resistance), and perceptual measures were obtained. Fundamental frequency and open quotient significantly decreased and speed quotient significantly increased in S1 and S2; jitter and shimmer significantly increased in S2 only. NS were perceived as non-smokers more reliably than S1 and S2 as smokers. Fundamental frequency, open quotient, and speed quotient were the most sensitive indicators of smoking effects on the female voice.

Jet Ventilation for the Excision of Vocal Cord Polyps in a Pregnant Patient

The anaesthetic management of patients presenting with laryngeal tumours and airway obstruction is difficult. We present the case of a pregnant woman at 30 weeks gestation who underwent surgical removal of two vocal cord polyps under general anaesthesia using jet ventilation

Evaluation of air‐QTM intubating laryngeal airway as a conduit for tracheal intubation in infants – a pilot study

Air-Q™ intubating laryngeal airway (ILA) has been used successfully as a conduit for tracheal intubation in pediatric difficult airway. However, its use as an airway device and conduit for intubation in infants is not yet evaluated. The primary objective was to evaluate ILA as a conduit for tracheal intubation in infants, and secondary objectives were to evaluate ILA in terms of ease of insertion and ventilation, oropharyngeal leak pressure (OLP), glottic view, and complications. Twenty infants with normal airway were included. After induction of general anesthesia and neuromuscular blockade, ILA (size 1.0/1.5) was inserted. Fiberoptic bronchoscope (FOB)-guided intubation and removal of ILA with the stabilizing stylet was attempted. The mean age and weight of the infants were 7.5 ± 2.3 months and 7.3 ± 1.8 kg. The ILA sizes 1.0 and 1.5 were inserted in 10 infants each according to the weight of the infants. The mean OLP was 18.5 ± 1.8 cm H₂O, and mean time for insertion of ILA was 13.3 ± 3.9 s. Glottic view was grade I in 6, grade II in 1, grade III in 4, and grade IV in nine infants. Tracheal intubation was successful in 19/20 infants. The mean endotracheal tube (ETT) insertion time and mean total time (ILA insertion to the confirmation of ETT placement) were 95.6 ± 32.3 s and 306.42 ± 120.2 s respectively. The ILA is a safe and easy-to-use supraglottic airway device for intubation with FOB in infants with normal airway. Insertion and removal of ILA are easy with satisfactory oropharyngeal seal and ventilation.

A randomized crossover comparison between the Laryngeal Mask Airway‐Unique™ and the air‐Q Intubating Laryngeal Airway in children*

The purpose of this randomized crossover study was to evaluate the feasibility of the air-Q intubating laryngeal airway (ILA) in clinical practice when compared with the Laryngeal Mask Airway-Unique(™) (LMA-U), the current standard of care for primary airway maintenance. We hypothesized that the ILA would have better airway seal pressures and laryngeal alignment than the LMA-U in anesthetized nonparalyzed children. The ILA is a newer supraglottic airway for children with design features that allow it to be used for primary airway maintenance and as a conduit for tracheal intubations. Fifty healthy children, 6-36 months of age, 10-15 kg, who were scheduled for elective surgery in which the use of a size two LMA-U and size 1.5 ILA would be appropriate for airway maintenance, were enrolled into this randomized crossover study. Primary outcome measures were airway leak pressures and fiberoptic grades of view. Secondary outcome measures included ease and time for successful insertion, incidence of gastric insufflation, ventilation parameters, and complications. There were no statistically significant differences in regard to the ease of device insertion, time to ventilation, gastric insufflation, and ventilation parameters between the ILA and the LMA-U. All devices were successfully placed on the first attempt, and there were no instances of failure. There were statistically significant differences in the airway leak pressure between the ILA (19.0 ± 5.4 cmH(2)O) and the LMA-U (16.1 ± 4.9 cmH(2)O), P = 0.001. There were also statistically significant differences in the fiberoptic grades of view between the ILA and LMA-U, P = 0.004. The ILA had higher airway leak pressures and superior fiberoptic grades of view when compared with the LMA-U and can be a suitable alternative to the LMA-U in children weighing 10-15 kg.

The air-Q® intubating laryngeal airway vs the LMA-ProSealTM: a prospective, randomised trial of airway seal pressure*

We performed a prospective, open-label, randomised controlled trial comparing the air-Q(®) against the LMA-ProSeal™ in adults undergoing general anaesthesia. One hundred subjects (American Society of Anesthesiologists physical status 1-3) presenting for elective, outpatient surgery were randomly assigned to 52 air-Q(®) and 48 ProSeal devices. The primary study endpoint was airway seal pressure. Oropharyngolaryngeal morbidity was assessed secondarily. Mean (SD) airway seal pressures for the air-Q(®) and ProSeal were 30 (7) cmH (2) O and 30 (6) cmH(2) O, respectively (p = 0.47). Postoperative sore throat was more common with the air-Q(®) (46% vs 38%, p = 0.03) as was pain on swallowing (30% vs 5%, p = 0.01). In conclusion, the air-Q(®) performs well as a primary airway during the maintenance of general anaesthesia with an airway seal pressure similar to that of the ProSeal, but with a higher incidence of postoperative oropharyngolaryngeal complaints.

Assessment of Phonation Threshold Pressure: A Critical Review and Clinical Implications

To describe the origins of the task elicitation procedure for determining phonation threshold pressure and, through a literature review and online survey, describe published procedural, environmental, and participant variable departures from the original methodology. Literature search terms included phonation threshold pressure, subglottal pressure and phonation, pressure measurement and phonation, lung pressure and phonation, and vocal fold oscillation onset. Inclusion criteria were limited to indirect assessment of phonation threshold pressure, English language publications between 1980 and 2009, and peer-reviewed journals. Studies including animals, computer or physical models, alaryngeal speakers, laryngeal airway resistance, or any airflow interruption technique were excluded. Twenty-four articles matched the inclusionary criteria. An online survey to query task elicitation procedures was then developed from the literature review. The scientific rationale for inclusion of phonation threshold pressure data was consistent across published studies; however, variations in procedural methodology for task elicitation were identified, as were environmental and participant inconsistencies that might affect phonation threshold pressure values. Findings of the online survey mirrored the inconsistencies identified in the literature review. The methodological differences for task elicitation identified in this comprehensive review of the literature and the online survey, while bringing into question the reliability of phonation threshold pressure measurement, illuminate scientific questions yet to be answered to further refine and potentially standardize phonation threshold pressure as a more reliable research and clinical measurement.

A New Algorithm for Pediatric Airway Management Using the Intubating Laryngeal Airway

Objective: 1) Evaluate the use of the intubating laryngeal airway (ILA) in providing safe endotracheal intubations in pediatric patients with difficult airways. 2) Present a management algorithm using direct laryngoscopy, rigid bronchoscopy, and the ILA for evaluating and securing the airway in pediatric patients with difficult airways. Method: The medical records of patients in whom the ILA was used to secure the airway from January 2009 to January 2011 were reviewed. We documented the circumstances necessitating airway management, success of the ILA, airway evaluation findings, and medical conditions contributing to the difficult airway. Results: A total of 50 patients had an ILA placed for airway management. Nine out of 50 (18%) were performed emergently. The median age was 59.8 months (range, 0.3-244.1 months), and the median weight was 19.0 kg (range, 2.6-86 kg). Four cases (8%) were unanticipated difficult airways, and 46 out of 50 (92%) were anticipated difficult airways. Comorbid conditions included craniofacial syndromes (n = 36), cervical spine instability or immobility (n = 9), and airway hemorrhage (n = 3). A total of 48 out of 50 (96%) patients were intubated on the first attempt through the ILA. In 2 patients intubation required a second attempt. The overall success rate using the ILA to secure the airway was 100%. Conclusion: ILA is safe and effective in pediatric patients with a difficult airway as a conduit for tracheal intubation. Our proposed algorithm for difficult pediatric airway provides a safe means for anesthesiologists and otolaryngolgists to evaluate and secure the airway in these patients.

Fiberoptic-guided tracheal tube placement through the air-Q® Intubating Laryngeal Airway: a performance study in a manikin

This study characterizes the performance and success rate for fiberoptic-guided tracheal tube placement through the air-Q(®) Intubating Laryngeal Airway (air-Q). Using a manikin, anesthesia trainees and staff anesthesiologists, experienced in fiberoptic-guided intubation, performed five consecutive fiberoptic-guided tracheal tube placements via the air-Q. Participant characteristics, procedure segment times, total procedure times, and observed failures were recorded. Linear mixed effect models with random slopes and intercepts were used to assess participant performance. Ten anesthesia trainees and ten staff anesthesiologists participated. Anesthesia trainees were younger and had practiced for fewer years compared to staff anesthesiologists. Gender was equally distributed between the groups. Both segmental and overall procedure times decreased from the first to the fifth trial among all participants, independent of experience level and gender. Overall mean procedure time decreased from 102±31 to 68±14s, representing a relative time reduction of 33% and a mean time difference of 34s [95% confidence interval (CI) 22-47s; p<0.0001]. Tracheal tube placement was successful in all attempts; however, three tracheal tube dislodgements occurred during air-Q removal (overall procedure success 97%). Fiberoptic-guided tracheal tube placement through the air-Q can be performed in a clinically acceptable period of time with high success by operators skilled in fiberoptic-guided intubation. Tracheal tube dislodgement during air-Q removal remains a potential risk that should be emphasized.

Tracheal autotransplantation: Guidelines for optimal functional outcome

Tracheal autotransplants can repair extensive hemilaryngectomy defects. This technique was introduced into the clinic some 10 years ago as a means of avoiding the mutilation of a total laryngectomy in selected patients with laryngeal cancer. Our goal was to give the morphometric guidelines that guarantee an optimal functional outcome. Retrospective case study. We morphometrically evaluated the structure and function of the larynx after autotransplantation. The close anatomic relationship between the larynx and the trachea made it possible to perform a morphometric analysis of the defect and the repair tissue before and after transplantation. Computed tomography images were used to measure the laryngeal and tracheal airway lumen and the length and width of the tracheal autotransplant. A 4-cm long cartilaginous tracheal transplant was available for reconstruction. Laryngeal repair was achieved with optimal restoration of the airway lumen at all laryngeal levels. We used the maximal amount of trachea that might reasonably be available for autotransplantation. This optimal morphologic repair led to the restoration of speech, swallowing, and respiratory functions. This study highlights a standardized approach for repairing a hemilaryngeal defect and selecting the appropriate amount of repair tissue. A unique characteristic of vascularized cartilaginous trachea is that it restores the airway lumen after extensive hemilaryngectomy. Tracheal autotransplantation should be included in the armamentarium of reconstructive laryngeal procedures.