A New and Simple Maneuver to Position the Left-Sided Double-Lumen Tube Without the Aid of Fiberoptic Bronchoscopy

A New Technique to Determine the Size of Double-lumen Endobronchial Tubes by the Two Perpendicularly Measured Bronchial Diameters

The cross-section of the mainstem bronchi is not completely round. For preoperative selection of a double-lumen endobronchial tube size, it may be necessary to measure the mediolateral and the anteroposterior bronchial diameters, which can be measured respectively on chest radiograph and computed tomography. With Internal Review Board approval and patients’ informed consent, 105 elective thoracic surgical patients who needed left-sided double-lumen tubes were enrolled. Double-lumen tube size was selected depending on the arithmetic mean of the mediolateral and anteroposterior bronchial diameters. Moreover, the outer diameters of the bronchial tube should be smaller than both mediolateral and anteroposterior diameters. The recommended bronchial diameter for each double-lumen tube size was chosen so that the mean of the two bronchial diameters was 0 to 2.0 mm larger than the upper limit of 95% confidence interval of the averaged outer diameter of the bronchial tube of the selected double-lumen tube. In no case was the predicted double-lumen tube size inappropriate. Generally, anteroposterior bronchial diameters appeared to be different from mediolateral diameters (P=0.001). The double-lumen tube size to be selected based on only one bronchial diameter was different from the one selected based on two perpendicularly measured bronchial diameters in 54.3% of patients (57/105). Preoperative selection of the double-lumen tube size based on the anteroposterior, mediolateral and mean bronchial diameters seems to be useful in that this may obviate the need to change an inappropriately sized double-lumen tube and may be helpful in reducing the related complications.

The role of micronutrients in the response to ambient air pollutants: Potential mechanisms and suggestions for research design

People living in regions of low socioeconomic status are thought to be prone to higher exposures to environmental pollutants, poor nutrition, and numerous preventable diseases and infections. Poverty correlates with pollution and malnutrition; however, limited studies examined their interrelationship. The well-studied, deleterious health effects attributed to environmental pollutants and poor nutrition may act in combination with produce more severe adverse health outcomes than any one factor alone. Deficiencies in specific nutrients render the body more susceptible to injury which may influence the pathways that serve as the mechanistic responses to ambient air pollutants. This review (1) explores specific micronutrients that are of global concern, (2) explains how these nutrients may impact the body's response to ambient air pollution, and (3) provides guidance on designing animal models of nutritional deficiency. It is likely that those individuals who reside in regions of high ambient air pollution are similarly malnourished. Therefore, it is important that research identifies specific nutrients of concern and their impact in identified regions of high ambient air pollution.

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.

Positioning of double-lumen tubes based on the minimum peak inspiratory pressure difference between the right and left lungs in short patients: a prospective observational study

BACKGROUND

Peak inspiratory pressures (PIPs) during one-lung ventilation (OLV) have served as a clinical marker that could indirectly verify the proper positioning of double-lumen tubes (DLTs). Patients of short stature are highly susceptible to initial DLT malpositioning.

OBJECTIVES

We investigated the usefulness of positioning left-sided DLTs using minimum PIP differences between the right and left lungs by comparing with the previously used method of auscultation without fibreoptic bronchoscopy (FOB). We also evaluated the difference in PIPs between the two lungs during OLV after the DLT was ideally positioned with FOB examination.

DESIGN

Prospective, observational study.

SETTING

A university hospital.

PATIENTS

One hundred and two female patients of short stature (≤160  cm).

INTERVENTIONS

Verification of DLT position was conducted by three sequential steps: auscultation; minimising the difference in PIP during each OLV; and verifying the resulting position by FOB.

MAIN OUTCOME MEASUREMENTS

Fibreoptic bronchoscopic view results of DLT position followed by the position adjustment using the minimum PIP difference method.

RESULTS

Repositioning the DLT using the minimum PIP difference led to clinically successful positioning of the DLT in 88% of patients and a more ideal placement of the tube than auscultation alone (69.6 vs. 11.8%, P <0.001). Additionally, the ideal position of DLTs verified by FOB showed that PIP differences were zero or ±1  mmHg in 93% of patients.

CONCLUSION

Positioning the DLT based on the minimum PIP difference between the right and left lungs as a supplementation to routine auscultation serves as an easy and reliable method for DLT positioning and may improve the accuracy of DLT positioning as an adjuvant to FOB in short patients.

TRIAL REGISTRATION

Clinicaltrial.gov identifier: NCT01533012.

"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.

[Correct placement of left-sided double lumen endotracheal tubes: a simple verification technique]

OBJECTIVE

Double lumen endotracheal tubes (DLTs) are used in thoracic surgery for selective bronchial intubation, which is required for single lung ventilation. Correct placement of the tube is checked by means of fiberoptic bronchoscopy. We present a simple alternative method to help confirm the correct placement of left-sided DLTs. The method consists of passing a suction catheter through the tracheal lumen of the tube. Our hypothesis was that if the catheter can be inserted without difficulty, the tube is correctly placed. The objective was to determine the sensitivity and specificity of that criterion.

MATERIAL AND METHODS

We studied patients scheduled for elective left pneumonectomy or lobectomy. After passing the catheter through the left-sided DLT, placement was checked by means of fiberoptic bronchoscopy (gold standard) and the results were compared with the placement assessment based on ease of insertion.

RESULTS

One hundred patients were included. The DLT was judged to be correctly placed in 88% of patients in whom the catheter was inserted without resistance. Bronchoscopy corroborated this finding in 84% of cases; the tube was found to be incorrectly placed in the remaining 4% of cases and had to be reinserted. Resistance was noted in 12% of cases and bronchoscopy confirmed that the tube was incorrectly placed in those patients.

CONCLUSIONS

This technique can be very useful in placing left-sided DLTs in situations where fiberoptic bronchoscopy is not available and if the anesthesiologist has a thorough command of the method. Our results support the routine use of this criterion as it is simple and easy to learn. It should be remembered, however, that confirmation of placement by means of fiberoptic bronchoscopy is currently the gold standard technique.