A new and simple maneuver to position the left-sided double-lumen tube without the aid of fiberoptic bronchoscopy

A Randomized Controlled Trial Comparing Novel Triple-Cuffed Double-Lumen Endobronchial Tubes with Conventional Double-Lumen Endobronchial Tubes for Lung Isolation

Placing a double-lumen endobronchial tube (DLT) in an appropriate position to facilitate lung isolation is essential for thoracic procedures. The novel ANKOR DLT is a DLT developed with three cuffs with a newly added carinal cuff designed to prevent further advancement by being blocked by the carina when the cuff is inflated. In this prospective study, the direction and depth of initial placement of ANKOR DLT were compared with those of conventional DLT. Patients undergoing thoracic surgery (n = 190) with one-lung ventilation (OLV) were randomly allocated into either left-sided conventional DLT group (n = 95) or left-sided ANKOR DLT group (n = 95). The direction and depth of DLT position were compared via fiberoptic bronchoscopy (FOB) after endobronchial intubation between the groups. There was no significant difference in the number of right mainstem endobronchial intubations between the two groups (p = 0.468). The difference between the initial depth of DLT placement and the target depth confirmed by FOB was significantly lower in the ANKOR DLT group than in the conventional DLT group (1.8 ± 1.8 vs. 12.9 ± 9.7 mm; p < 0.001). In conclusion, the ANKOR DLT facilitated its initial positioning at the optimal depth compared to the conventional DLT.

Volume of tidal gas movement in the nonventilated lung during one-lung ventilation and its relevant factors

Background

The passive ventilation of nonventilated lung results in tidal gas movement (TGM) and thus affects lung collapse. The present study aimed to measure the volume of TGM and to analyse the relevant factors of the TGM index (TGM/body surface area).

Methods

One hundred eight patients scheduled for elective thoracoscopic surgeries were enrolled. Lung isolation was achieved with a double-lumen endobronchial tube (DLT). The paediatric spirometry sensor was connected to the double-lumen connector of the nonventilated lung to measure the volume of TGM during one-lung ventilation (OLV) in the lateral position. The TGM index was calculated. The multiple linear regression was analysed using the TGM index as the dependent variables. Independent variables were also recorded: 1) age, sex, body mass index (BMI); 2) forced vital capacity (FVC), FEV₁/FVC, minute ventilation volume (MVV); 3) dynamic lung compliance (Cdyn) and peak inspiratory pressure (PIP) during dual lung ventilation; 4) the side of OLV; and 5) whether lung puncture for localization of the pulmonary nodule was performed on the day of surgery. The oxygen concentration in the nonventilated lung was measured at 5 min after OLV, and its correlation with the TGM index was analysed.

Results

The volume of TGM in the nonventilated lung during OLV was 78 [37] mL. The TGM index was 45 [20] mL/m² and was negatively correlated with the oxygen concentration in the nonventilated lung at 5 min after OLV. The multiple linear regression model for the TGM index was deduced as follows: TGM index (mL/m²) = C + 12.770 × a − 3.987 × b-1.237 × c-2.664 × d, where C is a constant 95.621 mL/m², a is 1 for males and 0 for females, b is 1 for right OLV and 0 for left OLV, c is BMI (kg/m²), and d is PIP (cmH₂O).

Conclusions

The TGM index is negatively correlated with the oxygen concentration of the nonventilated lung at 5 min after OLV. Sex, side of OLV, BMI and PIP are independently correlated with the TGM index.

Trial registration

This study was registered at ChiCTR (www.chictr.org.cn, ChiCTR1900024220) on July 1, 2019.

A simple blind placement of the left-sided double-lumen tubes

One-lung ventilation (OLV) has been commonly provided by using a double-lumen tube (DLT). Previous reports have indicated the high incidence of inappropriate DLT positioning in conventional maneuvers.After obtaining approval from the medical ethics committee of First Affiliated Hospital of Anhui Medical University and written consent from patients, 88 adult patients belonging to American society of anesthesiologists (ASA) physical status grade I or II, and undergoing elective thoracic surgery requiring a left-side DLT for OLV were enrolled in this prospective, single-blind, randomized controlled study. Patients were randomly allocated to 1 of 2 groups: simple maneuver group or conventional maneuver group. The simple maneuver is a method that relies on partially inflating the bronchial balloon and recreating the effect of a carinal hook on the DLTs to give an idea of orientation and depth. After the induction of anesthesia the patients were intubated with a left-sided Robertshaw DLT using one of the 2 intubation techniques. After intubation of each DLT, an anesthesiologist used flexible bronchoscopy to evaluate the patient while the patient lay in a supine position. The number of optimal position and the time required to place DLT in correct position were recorded.Time for the intubation of DLT took 100 ± 16.2 seconds (mean ± SD) in simple maneuver group and 95.1 ± 20.8 seconds in conventional maneuver group. The difference was not statistically significant (P = 0.221). Time for fiberoptic bronchoscope (FOB) took 22 ± 4.8 seconds in simple maneuver group and was statistically faster than that in conventional maneuver group (43.6 ± 23.7 seconds, P < 0.001). Nearly 98% of the 44 intubations in simple maneuver group were considered as in optimal position while only 52% of the 44 intubations in conventional maneuver group were in optimal position, and the difference was statistically significant (P < 0.001).This simple maneuver is more rapid and more accurate to position left-sided DLTs, it may be substituted for FOB during positioning of a left-sided DLT in condition that FOB is unavailable or inapplicable.

"Detachment of the carinal hook following endobronchial intubation with a double lumen tube"

Background

Carinal hooks increases difficulty at endotracheal intubation. Amputation of the carinal hook during passage and malpositioning of the tube to the hook are some of the potential problems related with left-sided Carlens double lumen tube (DLT). This article reports an amputation of the hook during a difficult selective intubation and aimed at calling the attention to complications associated with DLTs and the importance of fiberoptic bronchoscopy.

Case presentation

A 68 year-old woman was scheduled for right-sided thoracotomy in whom blind DLT insertion was performed. Narrowed trachea causes difficulty in rotating the DLT 90° counter-clockwise. After carinal hook was noticed upon visual inspection of the DLT, fiberoptic bronchoscopy was used to remove the missing part (with the use of forceps) from the right mainstem bronchus.

Conclusion

Insertion of DLTs with carinal hook is associated with technical problems and potentially life-threatening hazards have discouraged their use. Fiberoptic evaluation and repositioning solves most of the problems. Although amputation of the carinal hook has not been previously reported, clinicians should be alert. This case report emphasizes the utility of the fiberoptic bronchoscopy in the operating theatre for placement, positioning and inspection of the carinal hook DLT.