Laryngeal morbidity after tracheal intubation: the Endoflex(®) tube compared to conventional endotracheal intubation with stylet

Tracheal tube introducer-associated airway trauma: a systematic review

BACKGROUND

Tracheal tube introducers are recommended in airway management guidelines and are used increasingly as videolaryngoscopy becomes more widespread. This systematic review aimed to summarise the published literature concerning tracheal tube introducer-associated airway trauma.

METHODS

PubMed, EMBASE and CINAHL databases were searched using pre-determined criteria. Two authors independently assessed search results and performed data extraction and risk of bias assessments.

RESULTS

We included 16 randomised controlled trials and five observational studies involving 10,797 patients. There was heterogeneity in patient characteristics, airway manipulation, and airway trauma definition and measurement. One study investigated hyperangulated videolaryngoscopy. The standard stylet was the most commonly reported introducer, followed by bougie and stylets with additional features such as video or lighted tip. Airway trauma resulted in low harm and most frequently involved injuries to the upper airway, followed by laryngeal and tracheobronchial injuries. Eighteen studies were comparative and reported a reduction in airway trauma incidence when an introducer was used, with the exception of the standard stylet. Median (IQR [range]) pooled incidence of airway trauma associated with standard stylets was 13.1% (4.2-31.4 [0.5-79.2])% and with bougies was 5.4% (0.4-49.9 [0.0-68.0])%. The risk of bias of included studies was variable and many randomised trials were found to be at high risk due to non-robust measurement of the outcome.

CONCLUSIONS

Stylets might be associated with an increased risk of airway trauma compared with other devices or when no stylet was used, though the quality of evidence is modest. However, other introducers appear to be safe and reduce the risk of airway trauma.

Laryngotracheal Complications after Intubation for COVID-19: A Multicenter Study

Many of the patients with COVID-19 have suffered respiratory distress requiring prolonged endotracheal intubation (ETI) resulting in laryngotracheal complication with an impact on breathing, phonation, and swallowing. Our aim is to describe laryngeal injuries diagnosed after ETI in patients with COVID-19 in a multicentre study.

METHODS

A prospective descriptive observational study was conducted from January 2021 to December 2021, including COVID-19 patients with laryngeal complications due to ETI diagnosed in several Spanish hospitals. We analyzed the epidemiological data, previous comorbidities, mean time to ICU admission and ETI, need for tracheostomy, mean time on invasive mechanical ventilation until tracheostomy or weaning, mean time in ICU, type of residual lesions, and their treatment.

RESULTS

We obtained the collaboration of nine hospitals during the months of January 2021 to December 2021. A total of 49 patients were referred. Tracheostomy was performed in 44.9%, being late in most cases (more than 7-10 days). The mean number of days of ETI until extubation was 17.63 days, and the main post-intubation symptoms were dysphonia, dyspnea, and dysphagia, in 87.8%, 34.7%, and 42.9%, respectively. The most frequent injury was altered laryngeal mobility, present in 79.6%. Statistically, there is a greater amount of stenosis after late ETI and after delayed tracheostomy, not observing the data with the immobility alterations.

CONCLUSION

The mean number of days of ETI was long, according to the latest guidelines, with the need for several cycles of pronation. This long ETI may have had an impact on the increase of subsequent laryngeal sequelae, such as altered laryngeal mobility or stenosis.

Laryngeal Injury and Upper Airway Symptoms After Endotracheal Intubation During Surgery: A Systematic Review and Meta-analysis

Laryngeal injury from intubation can substantially impact airway, voice, and swallowing, thus necessitating multidisciplinary interventions. The goals of this systematic review were (1) to review the types of laryngeal injuries and their patient-reported symptoms and clinical signs resulting from endotracheal intubation in patients intubated for surgeries and (2) to better understand the overall the frequency at which these injuries occur. We conducted a search of 4 online bibliographic databases (ie, PubMed, Embase, Cumulative Index of Nursing and Allied Health Literature [CINAHL], and The Cochrane Library) and ProQuest and Open Access Thesis Dissertations (OPTD) from database inception to September 2019 without restrictions for language. Studies that completed postextubation laryngeal examinations with visualization in adult patients who were endotracheally intubated for surgeries were included. We excluded (1) retrospective studies, (2) case studies, (3) preexisting laryngeal injury/disease, (4) patients with histories of or surgical interventions that risk injury to the recurrent laryngeal nerve, (5) conference abstracts, and (6) patient populations with nonfocal, neurological impairments that may impact voice and swallowing function, thus making it difficult to identify isolated postextubation laryngeal injury. Independent, double-data extraction, and risk of bias assessment followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the Cochrane Collaboration's criteria. Twenty-one articles (1 cross-sectional, 3 cohort, 5 case series, 12 randomized controlled trials) representing 21 surgical studies containing 6140 patients met eligibility criteria. The mean patient age across studies reporting age was 49 (95% confidence interval [CI], 45-53) years with a mean intubation duration of 132 (95% CI, 106-159) minutes. Studies reported no injuries in 80% (95% CI, 69-88) of patients. All 21 studies presented on type of injury. Edema was the most frequently reported mild injury, with a prevalence of 9%-84%. Vocal fold hematomas were the most frequently reported moderate injury, with a prevalence of 4% (95% CI, 2-10). Severe injuries that include subluxation of the arytenoids and vocal fold paralysis are rare (<1%) outcomes. The most prevalent patient complaints postextubation were dysphagia (43%), pain (38%), coughing (32%), a sore throat (27%), and hoarseness (27%). Overall, laryngeal injury from short-duration surgical intubation is common and is most often mild. No uniform guidelines for laryngeal assessment postextubation from surgery are available and hoarseness is neither a good indicator of laryngeal injury or dysphagia. Protocolized screening for dysphonia and dysphagia postextubation may lead to improved identification of injury and, therefore, improved patient outcomes and reduced health care utilization.

REsidual Neuromuscular Block Prediction Score Versus Train-of-Four Ratio and Respiratory Outcomes: A Retrospective Cohort Study

BACKGROUND

Residual neuromuscular blockade is associated with an increased incidence of postoperative respiratory complications. The REsidual neuromuscular block Prediction Score (REPS) identifies patients at high risk for residual neuromuscular blockade after surgery.

METHODS

A total of 101,510 adults undergoing noncardiac surgery under general anesthesia from October 2005 to December 2018 at a tertiary care center in Massachusetts were analyzed for the primary outcome of postoperative respiratory complications (invasive mechanical ventilation requirement within 7 postoperative days or immediate postextubation desaturation [oxygen saturation {Spo2} <90%] within 10 minutes). The primary objective was to assess the association between the REPS and respiratory complications. The secondary objective was to compare REPS and train-of-four (TOF) ratio <0.90 on the strength of their association with respiratory complications.

RESULTS

A high REPS (≥4) was associated with an increase in odds of respiratory complications (adjusted odds ratio [OR], 1.13 [95% confidence interval {CI}, 1.06-1.21]; P < .001). In 6224 cases with available TOF ratio measurements, a low TOF ratio (<0.9) was associated with respiratory complications (adjusted OR, 1.43 [95% CI, 1.11-1.85]; P = .006), whereas a high REPS was not (adjusted OR, 0.96 [95% CI, 0.74-1.23]; P = .73) (P = .018 for comparison between ORs).

CONCLUSIONS

The REPS may be implemented as a screening tool to encourage clinicians to use quantitative neuromuscular monitoring in patients at risk of residual neuromuscular blockade. A positive REPS should be followed by a quantitative assessment of the TOF ratio.

Symptom clusters in head and neck cancer patients with endotracheal tube: Which symptom clusters are independently associated with health-related quality of life?

PURPOSE

The point of view of symptom clusters (SCs) may develop an efficient symptom management strategy to enhance health-related quality of life (HRQoL) in head and neck (HNC) patients with endotracheal tube (ETT). The study aims to investigate the possible SCs in HNC patients with ETT and determine whether there was an independent relationship between one or more SCs and HRQoL.

METHODS

A cross-sectional study design was adopted, and 203 HNC patients with ETT were recruited. They took measurements of General Information Questionnaire, MD Anderson Symptom Inventory-Head & Neck, and Twelve-Item Short-Form Health Survey (SF-12). Spearman correlations, partial correlations, and hierarchical cluster analysis were performed to determine latent number of SCs, and covariance analyses were used to determine independent associations between SCs and SF-12. This study followed STROBE Statement.

RESULTS

Pain SCs (pain, distressed, short of breath, and sadness), fatigue SCs (fatigue/weakness, restless, and sleepy), digestive SCs (appetite loss, constipation, and nausea), HNC-specific SCs (dry mouth and mucus), and tracheostomy-related SCs (difficulty swallowing and difficulty with voice and speech) were found. After adjusting covariant variables, this study found independent relationships of pain SCs and fatigue SCs with physical component summary of SF-12, and between fatigue SCs and mental component summary of SF-12.

CONCLUSIONS

Multiple SCs were found in those HNC patients. Pain SCs and fatigue SCs were independently associated with HRQoL. In process of caring HNC patients with ETT, it is vital to focus on SCs, especially on pain SCs and fatigue SCs, which might effectively improve patients' HRQoL.

Objective and Subjective Evaluations of the Effects of Different Types of Intubation Tube Applications on Voice Performance in the Early Postoperative Period

Objective

Changes in voice performance in the postoperative period due to trauma suffered during endotracheal intubation or edema occurring in the postoperative period are often observed. The present study aimed to evaluate the effects of different types of intubation tube applications on voice performance in the early postoperative period using objective and subjective voice analysis methods.

Materials and Methods

A total of 88 patients who underwent endotracheal intubation either using a cuffed endotracheal (n = 44) or spiral-embedded cuffed endotracheal (n = 44) tube were included in this study. An endotracheal tube of 7.5 mm was used for female patients and that of 8 mm was used for male patients. Preoperative acoustic voice analysis was performed, and fundamental frequency (F0), jitter%, and shimmer% values were recorded. In addition, the voice handicap index-30 (VHI-30) questionnaire was completed by the patients for subjective evaluation. The same procedure was repeated in the first 48 hours postoperatively. The preoperative and postoperative data were statistically compared. In addition, the effect of the type of endotracheal intubation tube on acoustic voice analysis parameters and VHI-30 scores was statistically evaluated.

Results

In the early postoperative period, a significant decrease in the F0 value and a significant increase in jitter% and shimmer% values were detected. The VHI-30 score was also found to be significantly higher in the early postoperative period than in the preoperative period. The effects of both the intubation tubes on voice performance were found to be similar.

Conclusion

Objective and subjective evaluations revealed that voice performance was declined in the early postoperative period after orotracheal intubation.

Claims for compensation after injuries related to airway management: a nationwide study covering 15 years

BACKGROUND

Securing the airway is one of the most important responsibilities in anaesthesia. Injuries related to airway management can occur. Analysis from closed claims can help to identify patterns of injury, risk factors and areas for improvement.

METHODS

All claims to The Norwegian System of Compensation to Patients from 1 January 2001 to 31 December 2015 within the medical specialty of anaesthesiology were studied. Data were extracted from this database for patients and coded by airway management procedures.

RESULTS

Of 400 claims for injuries related to airway management, 359 were classified as 'non-severe' and 41 as 'severe'. Of the severe cases, 37% of injuries occurred during emergency procedures. Eighty-one claims resulted in compensation, and 319 were rejected. A total of €1,505,344 was paid to the claimants during the period. Claims of dental damage contributed to a numerically important, but financially modest, proportion of claims. More than half of the severe cases were caused by failed intubation or a misplaced endotracheal tube.

CONCLUSION

Anaesthesia procedures are not without risk, and injuries can occur when securing the airway. The most common injury was dental trauma. Clear patterns of airway management that resulted in injuries are not apparent from our data, but 37% of severe cases were related to emergency procedures which suggest the need for additional vigilance. Guidelines for difficult intubation situations are well established, but adherence to such guidelines varies. Good planning of every general anaesthesia should involve consideration of possible airway problems and assessment of pre-existing poor dentition.

Intubation without use of stylet for McGrath videolaryngoscopy in patients with expected normal airway: A randomized noninferiority trial

BACKGROUND

During McGrath videolaryngoscope (VL) intubation, a styletted endotracheal tube maintaining an upward distal tip angle is recommended by some manufacturers. However, a styletted endotracheal tube can elicit rare but potentially serious complications. The purpose of this study was to demonstrate that a nonstyletted tube with exaggerated curvature would be noninferior to a styletted tube for orotracheal intubation using McGrath VL in patients with expected normal airway, by comparing the time to intubation and ease of intubation.

METHODS

One hundred forty patients, ages 19 to 70 years (American Society of Anesthesiologists physical status I-II), undergoing tracheal intubation for elective surgery were randomly allocated to the nonstylet group (n = 70) or the stylet group (n = 70). Anesthesia induction consisted of propofol, remifentanil, and rocuronium. The primary outcome was time to intubation assessed by a blind observer. Cormack and Lehane glottic grade, easy of intubation, and intubation difficulty score (IDS) were also assessed.

RESULTS

Median time to intubation [interquartile range] was not different between the nonstylet group and the stylet group (26 [24-32.5] s vs 27 [25-31] s, P = 0.937). There was no significant in median IDS between the nonstylet group and the stylet group (P = 0.695).

CONCLUSION

This study shows that a nonstyletted endotracheal tube with exaggerated curvature has a similar performance to a styletted tube with a hockey-stick curvature during intubation using McGrath VL regarding time taken to successful intubation and easiness of intubation.

Encountering unexpected difficult airway: relationship with the intubation difficulty scale

Background

An unexpected difficult intubation can be very challenging and if it is not managed properly, it may expose the encountered patient to significant risks. The intubation difficulty scale (IDS) has been used as a validated method to evaluate a global degree of intubation difficulty. The aims of this study were to evaluate the prevalence and characteristics of unexpected difficult intubation using the IDS.

Methods

We retrospectively reviewed 951 patients undergoing elective surgery in a single medical center. Patients expected to have a difficult intubation or who had history of difficult intubation were excluded. Each patient was assessed by the IDS scoring system with seven variables. Total prevalence of difficult intubation and the contributing individual factors were further analyzed.

Results

For the 951 patients, the difficult intubation cases presenting IDS > 5 was 5.8% of total cases (n = 55). The prevalence of Cormack-Lehane Grade 3 or 4 was 16.2% (n = 154). Most of the difficult intubation cases were managed by simple additional maneuvers and techniques such as stylet application, additional lifting force and laryngeal pressure.

Conclusions

Unexpected difficult airway was present in 5.8% of patients and most was managed effectively. Among the components of IDS, the Cormack-Lehane grade was most sensitive for predicting difficult intubation.

A comparison of conventional tube and EndoFlex tube for tracheal intubation in patients with a cervical spine immobilisation

BACKGROUND

The EndoFlex is a new type of tracheal tube with an adjustable distal tip that can be bent without the use of a stylet. The aim of this study was to compare a standard endotracheal tube with the EndoFlex tracheal tube for intubation in patients with simulated cervical spine injury.

METHODS

A group of 60 patients without any kind of the cervical spine injury, classified as the ASA physiological scale I or II and qualified for elective surgery procedures were intubated with the use of classical Macintosh laryngoscope, and either a standard endotracheal tube with the intubation stylet in it or EndoFlex tube without stylet. The subjects were randomized into two subgroups. All patients have had the cervical collar placed on their neck for the simulation of intubation procedure in case of the spinal injury.

RESULTS

The intubation procedure was performed by 16 anesthetists with different experience (5-19 yrs). Time of intubation with the use of EndoFlex tube was similar to that with a the use of standard endotracheal tube and intubation stylet: Me (median) 19.5 s [IQR (interquatile range) 18-50] vs. Me 20 s [IQR 17-60] respectively (p = 0.9705). No significant additional maneuvers were necessary during intubation with the use of EndoFlex tube in comparison with standard endotracheal tube (70% vs. 56.6%) (p = 0.4220). Subjective assessment of the usability of both tubes revealed that more anesthesiologists found intubations with the use of EndoFlex more demanding than intubation with conventional tracheal tube and intubation stylet. The assessment of usability: very easy 3.3% vs. 20%, easy 83.4% vs. 56.7%, difficult 10% vs. 20% and very difficult 3.3% vs. 3.3% for standard endotracheal tube with stylet and EndoFlex, respectively.

CONCLUSION

In conclusion we asses, that the EndoFlex tube does not improve intubation success rate, in fact it requires more maneuvers facilitating intubation and was found to be more difficult to use.