Inadvertent Endobronchial Intubation in a Patient With a Short Neck Length

Measuring the outward migration of the nasotracheal tube at vocal cords with head and neck extension: a novel approach using a flexible bronchoscope in patients undergoing head and neck oncosurgery

BACKGROUND

Head and neck extension achieves optimal surgical exposure during head and neck oncosurgeries. However, it can lead to cephalad migration of the tracheal tube, causing complications. Preventing shallow intubation is essential, especially in patients with difficult airway. Using an innovative technique, we aimed to measure the proximal migration of the nasotracheal tube at the vocal cords on neck extension in patients with difficult airway.

METHODS

We enrolled 60 adult patients undergoing head and neck oncosurgeries with a mouth opening of less than 1.5 cm. After nasotracheal intubation using a flexible bronchoscope (FB), the FB was introduced into the adjacent nostril and maneuvered to reach the glottis. The FB was used to view and align the intubation depth mark (IDM) on the tracheal tube (TT) with the vocal cords in the neutral position. The outward migration of the TT at the vocal cords with a 30° to 40° neck extension was measured using the same maneuver. Also, the TT tip-to-carina distance was noted in both neutral and extension using FB.

RESULTS

The mean proximal migration of the TT at the vocal cords during neck extension was 3±0.3 mm. The TT tip-to-carina distance increased by a mean of 20±7 mm with extension. The proximal migration contributed 15%, whereas elongation of the trachea contributed 85% to this increase.

CONCLUSIONS

The major contributing factor for the increase in TT tip-to-carina distance on neck extension was tracheal elongation rather than outward migration of the TT at vocal cords.

Optimising endotracheal length in adult cats: a retrospective CT study

OBJECTIVES

The aim of this study was to determine the maximal endotracheal insertion length by measuring the larynx to carina (L-C) distance by means of CT. An additional objective was to establish certain anatomical landmarks to optimise the process of endotracheal intubation (ETI).

METHODS

Head, neck and thoracic CT images from adult cats at a single referral hospital between 2013 and 2020 were retrospectively evaluated. After standardising and identifying key markers (larynx, carina and first rib) the L-C, larynx to first rib (L-1R) and first rib to carina (1R-C) distances were measured.

RESULTS

Forty-five adult cats were enrolled in the study, from which a total of nine different breeds were identified. The L-C distance was 14.3 ± 1.1 cm. This was longer in male (14.7 ± 1.1 cm) than in female cats (13.5 ± 0.7 cm). The first rib (1R) was 8.8 ± 0.7 cm from the larynx and the mean 1R-C distance was 5.4 ± 0.7 cm. The carina was found within the fifth intercostal space in 93.3% (n = 42) of the cats.

CONCLUSIONS AND RELEVANCE

The process of ETI in adult cats may be guided by using the L-C and L-1R distance for a maximal and optimal endotracheal tube introduction, respectively. In addition, the maximal insertion length may be guided by estimating the position of the carina parallel to the fifth intercostal space.

Portable Chest Radiography Immediately after Post-Cardiac Surgery; an Essential Tool for the Early Diagnosis and Treatment of Atelectasis: a Case Report

Atelectasis after endobronchial intubation (ETT) is a known complication of general anesthesia. In-bed auscultation of lungs and use of the 21/23 rule are the two suggestive, but not reliable, methods for the early detection of this event; however, none of them guarantees its prevention. The portable chest radiograph (CXR) is a simple, quick method to detect atelectasis and proper placement of the endotracheal tube in the intensive care unit (ICU). A case of postsurgical, ICU-admitted patient was presented in the report, demonstrating left (LT) lung atelectasis in immediate portable CXR without any evidence of respiratory or hemodynamic abnormality. Portable CXR showed that the tip of the endotracheal tube was located in the lumen of the right main bronchus, leading to LT lung total atelectasis. After repositioning of ETT to the lumen of the trachea, atelectasis was disappeared in early follow-up CXR.

Misplacement of Tracheostomy Tube in the Right Main Bronchus: a Rare Complication

A 38-year-old woman known case of metastatic squamous cell carcinoma of the cervical esophagus due to increasing dyspnea and stridor attributed to the pressure effect of the primary mass was scheduled for tracheostomy, which ended up in the right main bronchus. This rare complication occurred using a tracheostomy tube number 7.5 via a vertical tracheotomy over 4th and 5th tracheal rings. The misplacement was confirmed by chest X-ray and fiberoptic bronchoscopy, and the tracheostomy tube was successfully repositioned in a nonoperative approach.

A Formula for Estimating the Appropriate Tube Depth for Intubation

An estimation of the appropriate tubing depth for fixation is helpful to prevent inadvertent endobronchial intubation and prolapse of cuff from the vocal cord. A feasible estimation formula should be established. We measured the anatomical length of the upper-airway tract through the oral and nasal pathways on cephalometric radiographs and tried to establish the estimation formula from the height of the patient. The oral upper-airway tract was measured from the tip of the incisor to the vocal cord. The nasal upper-airway tract was measured from the tip of the nostril to the vocal cord. The tracts were smoothly traced by using software. The length of the oral upper-airway tract was 13.2 ± 0.8 cm, and the nasal upper-airway tract was 16.1 ± 0.9 cm. We found no gender difference ( p > .05). The correlations between the patients' height and the length of the oral and nasal upper-airway tracts were 0.692 and 0.760, respectively. We found that the formulas (height/10) - 3 (in cm) for oral upper-airway and (height/10) + 1 (in cm) for nasal upper-airway tract are the simple fit estimation formulas. The average error and standard deviation of the estimated values from the measured values were 0.50 ± 0.66 cm for the oral tract and 0.39 ± 0.63 cm for the nasal tract. Thus, considering the length of the intubation marker of each product (DM), we would like to propose the length of tube fixation as (height/10) + 1 + DM for nasal intubation and (height/10) - 3 + DM for oral intubation. In conclusion, the estimation formulas of (height/10) - 3 + DM and (height/10) + 1 + DM for oral and nasal intubation, respectively, are within almost 1 cm error in most cases.

A controlled trial to investigate whether the orientation of the bevel and angle of approach determine the side of endobronchial intubation in an adult manikin

One of the commonest complications of endotracheal intubation occurs when the tip of the endotracheal tube passes distal to the carina and enters one of the main bronchi. The perioperative practitioner may observe high airway pressures, hypoxia or even pneumothorax. The most common reason given for the high incidence of right endobronchial intubation is that the right main bronchus comes off the trachea at a more acute angle from the midline. We sought, however, to explore two other factors which may explain this phenomenon – the angle of the tube’s bevel and its trajectory of approach. We conducted a prospective controlled trial in which doctors from our department intubated the trachea of an adult manikin in three distinct sets using standard tube, reversed tubes and reversed laryngoscope blades. We found that the angle of the bevel and trajectory of approach determines the side of endobronchial intubation in an adult manikin.

Is prehospital endobronchial intubation a risk factor for subsequent ventilator associated pneumonia? A retrospective analysis

More than half of patients under mechanical ventilation in the intensive care unit (ICU) are field-intubated, which is a known risk factor for ventilator associated pneumonia (VAP). We assessed whether field endobronchial intubation (EBI) is associated with the development of subsequent VAP during the ICU stay. This retrospective, nested case-control study was conducted in a cohort of field-intubated patients admitted to an ICU of a teaching hospital during a three-year period. Cases were defined as field-intubated patients with EBI and controls corresponded to field-intubated patients with proper position of the tracheal tube on admission chest X-ray. Primary endpoint was the development of early VAP. Secondary endpoints included the development of early ventilator associated tracheo-bronchitis, late VAP, duration of mechanical ventilation, length of stay and mortality in the ICU. A total of 145 patients were studied (mean age: 54 ± 19 years; men: 74%). Reasons for field intubation were predominantly multiple trauma (49%) and cardiorespiratory arrest (38%). EBI was identified in 33 patients (23%). Fifty-three patients (37%) developed early or late VAP. EBI after field intubation was associated with a nearly two-fold increase of early VAP, though not statistically significant (30% vs. 17%: p = 0.09). No statistically significant difference was found regarding secondary outcomes. The present study suggests that inadvertent prehospital EBI could be associated with a higher incidence of early-onset VAP. Larger studies are required to confirm this hypothesis. Whether strategies aimed at decreasing the incidence and duration of EBI could reduce the incidence of subsequent VAP remains to be determined.

Shallow nasal RAE tube depth after head and neck surgery: association with preoperative and intraoperative factors

PURPOSE

To evaluate risk factors associated with improper postoperative nasal Ring-Adair-Elwyn (RAE) tube depth.

METHODS

We retrospectively enrolled 133 adult patients who were admitted to the intensive care unit (ICU) with the nasal RAE tube after head and neck surgery. Postoperative chest radiography was performed to confirm nasal RAE tube depth immediately after the patient was admitted to the ICU. Proper tube depth was defined as the tube tip between 2 and 7 cm above the carina. The patients were divided into the proper-depth group (78 patients) and the improper-depth group (55 patients). Patients' characteristics were collected. The risk factors for improper postoperative tube depth were assessed using logistic regression analysis.

MAIN RESULTS

All patients who showed improper tube depth had a shallow tube depth (the tube tip > 7 cm above the carina). Multivariable analysis revealed that tall stature [odds ratio (OR) 1.16; 95% confidence interval (CI) 1.08-1.25; P < 0.001], prolonged anesthesia duration (OR 1.16; 95% CI 1.02-1.32; P = 0.026), and right-sided surgical field as compared to the left (OR 0.36; 95% CI 0.14-0.93; P = 0.034) or median field (OR 0.25; 95% CI 0.07-0.85; P = 0.027) were risk factors associated with postoperative shallow tube depth.

CONCLUSIONS

Tall stature, prolonged anesthesia duration, and right-sided surgical field were independent risk factors for postoperative shallow nasal RAE tube depth.

Ideal Length of Oral Endotracheal Tube for Critically Ill Intubated Patients in an Asian Population: Comparison to Current Western Standards

Background

Endotracheal (ET) intubation is used to maintain the airway patency of patients during mechanical ventilation and is inserted at a particular depth into the trachea through the nose, mouth, or through an incision in the neck. The aim of our study was to validate the ideal length of an oral endotracheal tube (ETT) in the Asian population compared to Western standards.

Methods

Patient records with an oral ETT inserted between April 2011 and June 2015 in the Intensive Care Unit (ICU) of a hospital were retrospectively analyzed. The key variables included demographics, height, and ideal body weight of the patient, length of the oral ETT, and chest X-rays. Statistical analyses were performed using R software (https://cran.r-project.org/).

Results

There were 876 incidences of oral cuffed ETT insertions in 708 adult patients ≥ 18 years of age. The median ETT depth in all the ethnic groups (Chinese, Malay, Indians, and others) was 22 cm. The median depth of oral ETTs was 22 cm in males and 21 cm in females as compared to Western standards (males: P < 0.0001; females: P = 0.93). In ICU patients intubated with an ETT at an acceptable distance from the carina (2 - 5 cm), the median ETT depth was different in males (P < 0.0001) but was similar in females (P = 0.87).

Conclusion

We suggest that males and females in the Asian population, especially in South East Asia, should have their ETTs secured at the corner of mouth by at least 1 cm less in comparison to the Western population (22 cm in males and 20 cm in females).