Authors: Jagtar Singh Heir, D.O.; Javier Lasala, M.D.
ASA Monitor 03 2018, Vol.82, 28-29.
Jagtar Singh Heir, D.O., is Associate Professor of Anesthesiology and Perioperative Medicine, University of Texas M.D. Anderson Cancer Center, Houston.
Javier Lasala, M.D., is Assistant Professor of Anesthesiology and Perioperative Medicine, University of Texas M.D. Anderson Cancer Center, Houston.
It is suggested that robotically assisted thoracic surgeries can potentially benefit patients, resulting in smaller incisions, improved postoperative pain control, reduced recovery time and shorter hospital stays. While such benefits are still debated, most providers agree that this technology poses unique challenges for physician anesthesiologists providing lung isolation and one-lung ventilation. One new technology – video double lumen endobronchial tubes (VDLT) – offers a promising solution.
Lung Disease Expected to Rise
The incidence of lung and esophageal disease is expected to increase in the future, prompting a growing number of robotic thoracic procedures.1 Unfortunately, the size and space constraints of using robotics interferes with the positioning of conventional double lumen endobronchial tubes (DLT), the standard of care for airway management. In particular, the position of the robot can make the patient’s airway inaccessible, especially when the patient is in the lateral position and the head may be turned 90 to 180 degrees away from the provider.
Malpositioned DLTs can lead to complications from adverse airway events, including desaturation, tracheal trauma and bleeding. As such, many anesthesiologists rely on fiberoptic bronchoscopy (FOB) to confirm and maintain the tube’s accurate placement. Although the FOB is the gold standard for visualization of tracheobronchial anatomy, the view it provides is intermittent. Additionally, despite the increased usage of FOB, DLT malposition remains a chronic problem, occurring as much as 35 to 48 percent of the time, even in the hands of experienced providers.2 –4
Advances in VDLT technology have led to the addition of a miniature camera and light source embedded at the end of the tube. It is currently manufactured in left sizes (35-41F) and includes a port to flush away secretions from the camera. Otherwise, the design is similar to the conventional DLT.
A Comparison Study
In a 2015 study of 80 patients requiring lung isolation for robotic thoracic surgery, researchers compared VDLT to conventional DLT. Patients were randomized into either VDLT or DLT use. Attending anesthesiologists placed VDLT or DLT with conventional laryngoscopy or videolaryngoscopy, and then verified correct tube position through the view provided with either VDLT external monitor or FOB. The FOB was needed 13.2 percent of the time with VDLT, compared to 100 percent of the time when using DLT.
The study yielded several important findings. The use of VDLT resulted in an 86.8 percent reduction in FOB use. This is potentially beneficial in patients with compromised cardiopulmonary function. Depending on the laterality of surgery, each FOB may represent a potential interruption of ventilation, which may cause hypoxemia and hypercarbia that brittle patients may not tolerate well. Likewise, the FOB was needed only 7.7 percent of the time to correct dislodgement of the VDLT, compared to 100 percent of the time when dislodgement was noted in the DLT group. In effect, the provider is able to utilize the external monitor to correct dislodgement the majority of the time without having to use the FOB. This is important because FOBs aren’t always available, due to concurrent use by other providers, disrepair and cost.
Advances in double lumen endobronchial tube (VDLT) technology have led to the addition of a miniature camera and light source embedded at the end of the tube. It is currently manufactured in left sizes (35-41F) and includes a port to flush away secretions from the camera. Otherwise, the design is similar to the conventional DLT.
The continuous, real-time visualization of this technology enables quick recognition of dislodgement of the endobronchial tube, allowing rapid correction of dislodgement without FOB usage, and thus avoiding interruption of ventilation. Currently, the VDLT is only manufactured in left sizes (35-41F). Its design is similar to the conventional DLT, with the exception of an embedded camera with a light source, as well as a port to flush away secretions from the camera.
The study’s findings showed that the incidence of dislodgement was similar in both groups, which was to be expected, as both tubes are similar in shape and size. However, the key difference is that the FOB was needed 100 percent of the time to correct DLT dislodgement, compared with only needing the FOB 7.7 percent of the time to correct dislodgement in the VDLT group.
While most surgeons would maintain that their manipulation is gentle, even the most incidental manipulation can lead to dislodgement. Therefore, the reality is that dislodgement is common. Additionally, with VDLT technology, the cardiothoracic anesthesia team can determine, in real time, whether adverse airway events are due to the tube dislodgement or something unrelated.
Training and Equipment Considerations
Despite the advantages of VDLT technology, the three biggest barriers to adopting the technology are secretions, cost and the perceived investment in physician training. Training is achieved easily and can be hastened with videolargnoscopy. This approach allows experienced providers to point out subtle modifications in insertion technique, while still enabling the trainee to perform the actual intubation.
Second, secretions can still be an issue, as they can obscure the camera lens. However, in the vast majority of cases, the secretions can be cleared, and if not, the FOB can be utilized to gain improved visualization.
Finally, VDLT technology is four times the cost of conventional DLT. However, costs can vary from institution, depending on a multitude of factors. For example, institutions can choose to either buy or lease their equipment, depending on their clinical volume. Therefore, in a scenario where equipment is leased and usage is high, the resultant cost will invariably decrease with each usage. Additionally, other costs, such as maintenance and sterilization, can vary among institutions. Ultimately, the decision to incorporate VDLT into practice must be made taking into account the unique considerations at each institution. However, the continuous, real-time visualization offers a significant value to the thoracic anesthesia practice by impacting patient safety.
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Klein U, Karzai W, Bloos F, et al. Role of fiberoptic bronchoscopy in conjunction with the use of double-lumen tubes for thoracic anesthesia: a prospective study. Anesthesiology. 1998;88(2):346–350.
Campos JH, Hallam EA, Van Natta T, Kernstine KH . Devices for lung isolation used by anesthesiologists with limited thoracic experience: comparison of double-lumen endotracheal tube, Univent torque blocker, and Arndt wire-guided endobronchial blocker. Anesthesiology. 2006;104(2):261–266.
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