Robertshaw double lumen tubes: a reappraisal thirty years on

The Single-connector Technique for Initial Placement of Double-lumen Tubes

Due to the presence of major lung or extra-pulmonary pathology, which may be unilateral or bilateral, the initial placement of a double-lumen tube is not always straightforward. Although fibreoptic bronchoscopy is often used to confirm “correct” placement, a “blind” technique is frequently used for the initial insertion. The currently widely taught blind technique involves tracheal cuff inflation and ventilation of both lungs as a first manoeuvre, with a subsequent assessment of single-lung ventilation by clamping off, in turn, the two limbs of the double-lumen tube double-connector. An alternative approach involves the bronchial cuff being inflated first, and then using a single-connector to transfer ventilation from one lung to the other. In this paper this technique is described and compared to the more traditional method. On a purely “number of steps” basis, the single-connector approach has several advantages. Furthermore, use of a technique that involves bronchial cuff inflation and single-lung ventilation as a first manoeuvre may reduce the risk of a temporarily malplaced double-lumen tube creating a potentially harmful ball-valve effect in a partially obstructed lobe or lung.

Comparison of double-lung jet ventilation and one-lung ventilation for thoracotomy

BACKGROUND AND OBJECTIVE

Thoracic surgery requires immobilization of the operating area. Usually, this is achieved with one-lung ventilation (OLV), however this may still lead to some movement. High-frequency jet ventilation (HFJV) may be an alternative way of ventilation in thoracic surgery. The purpose of this study was to determine the effectiveness of HFJV as an alternative option to OLV for thoracic procedures.

METHODS

Sixty patients were randomized to receive either HFJV (n = 29) or OLV (n = 31) during the operation. During the course of the study 10 patients were excluded (4 patients in HFJV group and 6 patients in OLV group). The following haemodynamic and ventilatory parameters were recorded: heart rate, systolic and mean blood pressure, ventricular stroke volume, cardiac index, systemic vascular resistance, peak inspiratory pressure, oxygen saturation, PaO2 and PaCO2. Overall parameters were documented before the initiation of the chosen mode of ventilation every 15 min during the operation.

RESULTS

Patients in both groups showed comparable cardiovascular function. Mean values of peak inspiratory pressure were significantly higher in the OLV group. Oxygen saturation values were statistically higher in the HFJV group. PaCO2 values were similar in both during surgery, but were higher in the OLV group after awakening. Mean values of shunt fraction were lower in the HFJV group. Lower values of peak inspiratory pressure were therefore associated with higher partial pressure of carbon dioxide levels in the HFJV group. In the OLV group, 44% of patients experienced a postoperative sore throat. Operating conditions were comparable.

CONCLUSION

HFJV is safe option, comparable to OLV and offers some advantages for open-chest thoracic procedures.

Methods of lung separation

In the last few years, video assisted thoracoscopy, which allows a wide variety of diagnostic and therapeutic procedures, has been introduced into clinical practice. A growing enthusiasm for minimally invasive surgical approaches and improvements in video endoscopic surgical equipment has resulted in the widespread use of this technique. Most video assisted thoracoscopy procedures require a well-collapsed lung and should only be included in the absolute indication for one-lung ventilation. Following placement of a double lumen tube, it is the standard of care to check the tube is positioned correctly using fiberoptic bronchoscopy. The role of the right-sided double lumen tube is discussed in detail in this review. Finally, there are alternatives to the use of the double-lumen tube to achieve lung separation, such as the Univent tube or an independent bronchial blocker. In many situations the double-lumen tube cannot be inserted, due to a difficult airway or at the conclusion of the procedure changing the double lumen tube to a single lumen tube may result in loss of control over the airway. In such situations, it is essential for the anesthesiologists to be familiar with the existing alternatives to the double-lumen tube.

The flexible bronchoscope. A tool for anesthesiologists

Fiberoptic intubation is the technique of choice in management of a difficult intubation. It should be a first choice, not a last resort after attempts with conventional techniques have failed. It should be mastered by all physicians involved in airway management. The technique is cost-effective because it avoids airway trauma and cancellation of surgical cases because of failed intubation. The flexible bronchoscope for airway management as a diagnostic, therapeutic, and problem-solving tool is not used to the degree that it deserves. Anesthesiologists and other critical care physicians should master the technique and use it on a daily basis. The widespread use of the instrument for airway management deserves encouragement.

Predicting the size of a double-lumen endobronchial tube based on tracheal diameter

We assessed whether using the tracheal diameter to predict the correct size of the left double-lumen endobronchial tube (DLT) could be used for our generally smaller sized Asian patients. Sixty-six consecutive adult patients under anesthesia for elective surgery requiring the use of a DLT were studied. The size of the left-sided DLT used was based on the width of patients' trachea measured from the preoperative posterior-anterior chest radiograph. The placement of the DLT was standardized and confirmed with fiberoptic bronchoscopy. The correct size of the DLT was the largest size tube inserted into the left bronchus with a small air leak detectable when the endobronchial cuff was deflated but not exceeding the recommended resting volume when inflated for lung isolation. Using this method of choosing our DLT, we found that an oversized DLT was often chosen especially among our female Asian patients. The overall positive predictive values for the male and female patients were 77.3% and 45.5%, respectively. We postulate that this could be due to our criteria for correct DLT size or that our local Asian patients, especially the females, were smaller and shorter.

IMPLICATIONS

This study assessed whether the correct double-lumen endobronchial tube size could be predicted from tracheal diameter measurements taken from the chest radiograph. We found that this method of choosing the double-lumen endobronchial tubes was not always reliable.

Airway troubles related to the double-lumen endobronchial tube in thoracic surgery

PURPOSE

Several case reports indicate critical respiratory complications in relation to the double-lumen endobronchial tube (DLT). A prospective survey for the airway problems in using the DLT is presented.

METHODS

One hundred adult patients undergoing thoracotomy for lung cancer were investigated. Tube malposition and airway obstruction were searched using a fiber-optic scope. The endobronchial cuff was positioned just below the trachcal carina while the trachea was intubated with a DLT (Rüsch). The distances of displacement, from the tracheal carina to the bronchial cuff, were measured during anesthesia using an epidural catheter, which had marks every 5 mm. The distances for correcting the tube position were measured at both the bronchial cuff and the level of the teethPaO₂,PaCO₂ andSPO₂ were also measured.

RESULTS

Malposition (displacement over 5 mm from the correct position) was found in 42 patients, and 40 of them were in a withdrawal direction, occurring at the postural change and during one-lung ventilation, especially during manipulation of the lung hilum. Correcting distances at the level of the teeth were 15.3-3-times longer than those at the bronchial cuff. Airway deformities and gradual withdrawal of the bronchial cuff were found in association with surgical manipulation. Obstruction occurred at the tips of the tracheal tube in four patients and the bronchial tube in six patients, and at the tip of both in two patients. Hypoxemia (PaO₂<60 mmHg) occurred in four patients and hypercapnea (PaCO₂>60 mm Hg) in two patients.

CONCLUSION

Most of the DLT obstructions were associated with withdrawal malposition. Great attention to DLT displacement and airway deformity is advised.

Independent lung ventilation

Situations in which independent lung ventilation may be of use include massive hemoptysis, pulmonary alveolar proteinosis, risk of interbronchial aspiration, unilateral lung injury, single lung transplant, and BPF. Any decision to attempt independent lung ventilation should take into consideration the many technical difficulties associated with the procedure. They include difficulties in the placement of DLTs and monitoring tube position, the risk of tube displacement, and the risk of airway trauma. The clinician also must consider the costs in terms of available manpower and resources. Maintaining a patient on independent lung ventilation requires highly skilled nursing care, specialized monitoring devices, and readily available FOB. Even with these limitations, independent lung ventilation may be of use in certain clinical situations when standard methods have failed.

"Blind" placement of plastic left double-lumen tubes

A prospective analysis of placement of left-sided plastic double-lumen tubes in 100 patients is presented. Intubation of the left bronchus was successfully accomplished using only auscultation and clinical signs ("blind" placement) in 91 patients. Double-lumen tubes were positioned in less than five minutes in 84 patients. The most common problem encountered (30%) was initial intubation of the right main bronchus. Seven of these patients required bronchoscopic assistance to guide the tube into the left bronchus. There were four minor intraoperative complications due to DLT malposition that were recognized and corrected by withdrawing the tube slightly back in the bronchus. The plastic double-lumen tubes functioned properly during the procedure in all 100 patients.