Airway lesions caused by prolonged intubation with standard and with anatomically shaped tracheal tubes. A post-mortem study

Intubation-Related Laryngeal Deficiency and Vocal Fold Immobility in Pediatric Premature Patients

OBJECTIVES/HYPOTHESIS

We report a posterior laryngeal rating system and measures of voice disability in pediatric patients undergoing phonosurgery for vocal fold paralysis. Posterior glottic deficiency may account for persistent voice disability.

STUDY DESIGN

Retrospective Study.

METHODS

Retrospective analyses of 66 subjects with primary unilateral vocal fold paralysis were reviewed for the status of posterior glottis and voice disability (Pediatric Voice Handicap Index [pVHI]). Gestation age (GA), weight, and medical/surgical history were reviewed. The width, length, and depth of the larynx were analyzed to create a reproducible rating scale.

RESULTS

Mean GA was 29 weeks, with an intubation history for all subjects, with 90% having a left vocal fold immobility. Cardiac surgery was performed in 92% of subjects. A progressive rating (type 0-3) Benjamin Defect Severity Scale (BDSS) was developed to rate the absence or presence of a posterior abnormality. BDSS-2 and BDSS-3 subjects were more likely to have low birth weight. Extremely preterm GA was more likely to be associated with BDSS-1 (mild) or BDSS-2. History of multiple and prolonged intubations were seen more frequently in BDSS-2 or BDSS-3. Post-op pVHI reduced an average of 15 points for BDSS-0 to BDSS-2, but only 3 points for BDSS-3. Post-op pVHI matched normal values for preintervention dysphonic children.

CONCLUSIONS

The presence of a persistent breathy voice after intervention for unilateral vocal fold immobility is potentially associated with posterior glottic defects. Low birth weight with multiple/prolonged intubation is more likely to be present with higher-grade BDs, whereas low GA is more likely to be associated with BDSS-1 to BDSS-2.

LEVEL OF EVIDENCE

4 Laryngoscope, 2021.

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.

Incidence and Outcomes of Acute Laryngeal Injury After Prolonged Mechanical Ventilation

OBJECTIVES

Upper airway injury is a recognized complication of prolonged endotracheal intubation, yet little attention has been paid to the consequences of laryngeal injury and functional impact. The purpose of our study was to prospectively define the incidence of acute laryngeal injury and investigate the impact of injury on breathing and voice outcomes.

DESIGN

Prospective cohort study.

SETTING

Tertiary referral critical care center.

PATIENTS

Consecutive adult patients intubated greater than 12 hours in the medical ICU from August 2017 to May 2018 who underwent laryngoscopy within 36 hours of extubation.

INTERVENTIONS

Laryngoscopy following endotracheal intubation.

MEASUREMENTS AND MAIN RESULTS

One hundred consecutive patients (62% male; median age, 58.5 yr) underwent endoscopic examination after extubation. Acute laryngeal injury (i.e., mucosal ulceration or granulation tissue in the larynx) was present in 57 patients (57%). Patients with laryngeal injury had significantly worse patient-reported breathing (Clinical Chronic Obstructive Pulmonary Disease Questionnaire: median, 1.05; interquartile range, 0.48-2.10) and vocal symptoms (Voice Handicap Index-10: median, 2; interquartile range, 0-6) compared with patients without injury (Clinical Chronic Obstructive Pulmonary Disease Questionnaire: median, 0.20; interquartile range, 0-0.80; p < 0.001; and Voice Handicap Index-10: median, 0; interquartile range, 0-1; p = 0.005). Multivariable logistic regression independently associated diabetes, body habitus, and endotracheal tube size greater than 7.0 with the development of laryngeal injury.

CONCLUSIONS

Acute laryngeal injury occurs in more than half of patients who receive mechanical ventilation and is associated with significantly worse breathing and voicing 10 weeks after extubation. An endotracheal tube greater than size 7.0, diabetes, and larger body habitus may predispose to injury. Our results suggest that acute laryngeal injury impacts functional recovery from critical illness.

Laryngeal Injury and Upper Airway Symptoms After Oral Endotracheal Intubation With Mechanical Ventilation During Critical Care: A Systematic Review

OBJECTIVES

To systematically review the symptoms and types of laryngeal injuries resulting from endotracheal intubation in mechanically ventilated patients in the ICU.

DATA SOURCES

PubMed, Embase, CINAHL, and Cochrane Library from database inception to September 2017.

STUDY SELECTION

Studies of adult patients who were endotracheally intubated with mechanical ventilation in the ICU and completed postextubation laryngeal examinations with either direct or indirect visualization.

DATA EXTRACTION

Independent, double-data extraction and risk of bias assessment followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Risk of bias assessment followed the Cochrane Collaboration's criteria.

DATA SYNTHESIS

Nine studies (seven cohorts, two cross-sectional) representing 775 patients met eligibility criteria. The mean (SD; 95% CI) duration of intubation was 8.2 days (6.0 d; 7.7-8.7 d). A high prevalence (83%) of laryngeal injury was found. Many of these were mild injuries, although moderate to severe injuries occurred in 13-31% of patients across studies. The most frequently occurring clinical symptoms reported post extubation were dysphonia (76%), pain (76%), hoarseness (63%), and dysphagia (49%) across studies.

CONCLUSIONS

Laryngeal injury from intubation is common in the ICU setting. Guidelines for laryngeal assessment and postextubation surveillance do not exist. A systematic approach to more robust investigations could increase knowledge of the association between particular injuries and corresponding functional impairments, improving understanding of both time course and prognosis for resolution of injury. Our findings identify targets for future research and highlight the long-known, but understudied, clinical outcomes from endotracheal intubation with mechanical ventilation in ICU.

Anatomical Shape of the Airways in Two Different European Populations

Lateral radiographs of the airways were taken in 20 men and 24 women lying supine with the neck in the normal position. The mean configuration of the airways for men and women is presented in a standard coordinate system. The results (contours of the airways) are compared to those of a Swedish study since the same method was applied in order to find out, if the established model is valid for other populations. Significant differences were found between the two population groups as well as between males and females. This indicates both inter-racial and inter-sexual modification of the anatomical shape of the airways.

Piloting a novel porcine model for endolaryngeal injury following prolonged intubation

OBJECTIVES

(1) To develop a practical animal model of endolaryngeal damage secondary to prolonged endotracheal intubation. (2) To demonstrate the contribution of chronic hypoxia to laryngeal injury in the context of this model.

METHODS

Four Sus scrofa piglets were anaesthetized and intubated for 24h. Two animals were maintained in a state of constant hypoxia (pO(2)<60 mmHg) while two others were ventilated with 100% oxygen. Prior to sacrifice, fluorescein dye was infused intravenously to highlight areas of hypoperfusion. The larynx and trachea were then harvested for gross and histological examination.

RESULTS

All four specimens demonstrated areas of edema, erythema, and ulceration on gross examination. Areas of significant histological inflammation, ulceration, and necrosis involved tube-mucosa contact, in particular, the arytenoids, the interarytenoid area, and the subglottis.

CONCLUSIONS

This animal model represents a practical and novel means for the investigation and treatment of laryngeal injury secondary to prolonged endotracheal intubation. Significant injury to the endolarynx was evident after only 24h of intubation and the injury involved similar areas within the larynx as described in human studies. Although clinical experience suggests that chronic hypoxia is a risk factor for endolaryngeal injury, this model did not provide experimental evidence to support this observation, most likely due to the small study size.

Late outcome from percutaneous tracheostomy using the Portex kit

OBJECTIVE

To assess late outcome following percutaneous tracheostomy using the Portex kit (Hythe, Kent, UK).

DESIGN

Prospective observational cohort study.

SETTING

Teaching hospital.

PATIENTS

Forty-nine consecutive patients who underwent percutaneous tracheostomy in the ICU using the Portex kit and who survived 6 months after the procedure.

INTERVENTIONS

Questionnaires regarding six symptoms were sent to all 49 surviving patients; the 39 respondents were invited to attend for review. Thirteen patients underwent pulmonary function testing, of whom 10 also underwent fiberoptic laryngotracheoscopy under local anesthesia.

RESULTS

The most common symptom was a minor change in voice. One patient had required treatment for symptomatic tracheal stenosis by the time of review; one was referred for revision of a tethered scar. Pulmonary function testing was easily performed by all patients and revealed no evidence of upper airway obstruction. Tracheoscopy likewise showed no evidence of tracheal stenosis.

CONCLUSIONS

One of 49 patients had developed tracheal stenosis. None of the patients attending for detailed review showed any sign of late complications other than one tethered scar.

Closure of a tracheoesophageal fistula by bronchoscopic application of fibrin glue and decontamination of the oral cavity

A tracheoesophageal fistula was successfully closed with a fibrin adhesive applied by means of a fiberoptic bronchoscope, instead of by esophagoscopy. To facilitate closure of the fistula, the technique was combined with decontamination of the oral cavity, to avoid bacterial contamination. The procedure is proposed as an alternative to surgery for critically ill patients.

Influence of ventilatory technique on pulmonary baroinjury in baboons with hyaline membrane disease

To assess the influence of ventilatory technique on pulmonary baroinjury in experimental hyaline membrane disease, we randomized 24 premature baboons to six treatment groups according to ventilator (PPV, positive pressure ventilator; HFO, high frequency oscillator; HFI, high frequency flow interrupter) and O2 therapy FIO2 as clinically indicated, or FIO2 1.0). PaCO2 was adjusted by varying pressure amplitude, and for PPV, also by rate (less than 60/min). HFO and HFI were set at a frequency of 10 Hz. Animals were cared for with standard NICU techniques until death or sacrifice at 11 days. One animal died at delivery and was excluded from data analysis. There were no intergroup differences in Paw, Pa/AO2, PaCO2 or oxygenation index (IO2 = [Pa/AO2]/Paw) prior to death of the first study animal at 13 h. Animals who subsequently developed airleak had higher Paw, lower Pa/AO2 and lower IO2 during this period. The degree of airleak was significantly less with HFO compared to PPV or HFI. The effect of O2 exposure did not appear different with respect to the degree of airleak or the frequency of severe tracheal injury, although survival was shortened. Severe tracheal injury was more frequent with HFI compared to PPV or HFO. BPD was found only in 100% O2 exposed animals surviving greater than 1 wk. Management of premature baboons with HFO and appropriate O2 resulted in less severe airleak, 100% survival, and no evidence of severe tracheal injury or BPD. These outcomes were not achieved with clinically similar strategies using PPV or HFI.