Abstract
Objective
The aim of this study was to assess the right placement of the double lumen endotracheal tube with fluoroscopic guidance, which is used in first intention prior to the fiberscope in our institution.
Methods
This was a prospective observational study. The study was conducted in vascular and thoracic operating rooms. We enrolled 205 patients scheduled for thoracic surgery, with ASA physical statuses of I (n = 37), II (n = 84), III (n = 80), and IV (n = 4). Thoracic procedures were biopsy (n = 20), wedge (n = 34), culminectomy (n = 6), lobectomy (n = 82), pneumonectomy (n = 4), sympathectomy (n = 9), symphysis (n = 47), and thymectomy (n = 3). The intubation with a double lumen tube was performed with the help of a laryngoscope. Tracheal and bronchial balloons were inflated and auscultation was performed after right and left exclusions. One shot was performed to locate the position of the bronchial tube and the hook. Fluoroscopic guidance was used to relocate the tube in case of a wrong position. When the fluoroscopic guidance failed to position the tube, a fiberscope was used. Perioperative collapse of the lung was assessed by the surgeon during the surgery.
Results
Correct fluoroscopic image was obtained after the first attempt in 58.5% of patients therefore a misplaced position was encountered in 41.5%. The fluoroscopic guidance allowed an exact repositioning in 99.5% of cases, and the mean duration of the procedure was 8 minutes. A fiberscope was required to move the hook for one patient. We did not notice a moving of the double lumen endotracheal tube during the surgery. The surgeon satisfaction was 100%.
Conclusion
The fluoroscopy evidenced the right position of the double lumen tube and allowed a right repositioning in 99.5% of patients with a very simple implementation.
Keywords
Carlens tube; fluoroscopy; one-lung ventilation; thoracic surgery;
1. Introduction
In thoracic surgery, the collapse of the lung during the surgical procedure is systematically required. With a double lumen tube, the left or the right lung can be ventilated or deflated separately. Several double lumen tubes are available. A Carlens tube has a left bronchial channel, a right tracheal channel, and a hook. A White tube has a right bronchial channel, a left tracheal channel, and a hook. In the White tube, a hole is set in the bronchial balloon in order to maintain right lobar superior bronchus ventilation. Other double lumen tubes without hooks have been launched. Furthermore, for selective ventilation, a blocker introduced in a single lumen tube can be an alternative. In our institution, we have chosen the Carlens tube. In case of very difficult intubation, a single lumen tube is introduced nasally and a blocker guided with a fiberscope is placed in the right or left bronchus through the single tube.
Auscultation with a stethoscope is always required to check the position of the double lumen tube. Nevertheless we know that mere auscultation fails to locate the perfect position of the tube in 37% of patients.1 A fiberoptic bronchoscopy should be used to identify a wrong position because the clinical confirmation is not sufficient.2 After a learning curve and a training, anesthesiologists should be familiar with that technique.
Ever more fluoroscopic devices are available in operating rooms, so their use to check the position of the double lumen tube requires evaluation. Therefore we conducted a prospective study to evaluate the reliability, simplicity and safety of the fluoroscopic control and guidance.
2. Materials and methods
Approval from our hospital Ethics Committee was obtained for this prospective observational study.
This was a monocentric study performed in a University Hospital involved in research, teaching, and care. It is a regional hospital classified at level 3 providing 2455 beds, located in Rouen and the reference for the upper-Normandy region in France.
Thoracotomy, video-thoracotomy, or robot-assisted thoracotomy scheduled patients in a 1 year period were recruited. All patients orally received hydroxyzine (0.5–1 mg/kg; UCB Pharma SA, Braine-l'Alleud, Belgium) or alprazolam (0.01 mg/kg; Pharmacia–Upjohn, Uppsala, Sweden) 1 hour before surgery.
General anesthesia was given with remifentanil and propofol. Myorelaxation was obtained with atracurium. The Carlens tube (Vygon US, Montgomeryville, PA, USA) was introduced between the vocal cords with a laryngoscope. When the bronchial balloon crossed the vocal cords (it was in a vertical position), the rigid leader was taken off. Then, at the same time, the tube was pushed down and a 270° rotation was performed clockwise. Both balloons were inflated. Right and left alternative exclusions and auscultations were performed and, whatever the auscultation result, the double lumen endotracheal tube was controlled with fluoroscopy.
The fluoroscopic device was set to pulsing X-ray beam (1 image/second), low dose, maximum collimation. The patient was placed as close as possible to the image intensifier. These adjustments resulted in a reduction of absorbed doses.
When an incorrect position was encountered after the fluoroscopy, the double lumen tube was relocated under fluoroscopic visualization. After the perfect location of the tube was secured and confirmed by the fluoroscopy, a second auscultation checked the right and the left ventilation.
The double lumen tube implementation duration was recorded from positioning to withdrawal of the image intensifier.
The final radiography showing the right place of the double lumen tube and the patient dose summary was printed and stored in the patient file. The unit of emitted radiation dose of ionizing radiation (X-ray) retained for each patient was the dose area product square meter expressed in mGy.m2, the SI unit used to measure the administered dose at the exit of the ionizing chamber of the radiation device (OEC 9900 Elite; GE Healthcare, Little Chalfont, Buckinghamshire, United Kingdom). The cumulative dose for each individual was recorded as a reference. The surgeon's satisfaction during the surgery was appreciated as bad, medium, or perfect. The double lumen tube placement was considered perfect when the hook was visualized in the right bronchus and when the left lumen of the Carlens tube was located in the left bronchus, representing an open angle, strictly placed on the carina (Fig. 1).
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3. Results
We enrolled 205 patients scheduled for thoracic surgery: mean age 58.5 years (range, 17–92 years); mean weight 71.6 kg (range, 42–124 kg); and mean height 169 cm (range, 144–192 cm). Their ASA physical status was I (n = 37), II (n = 84), III (n = 80), and IV (n = 4). Thoracic procedures were biopsy (n = 20), wedge (n = 34), culminectomy (n = 6), lobectomy (n = 82), pneumonectomy (n = 4), sympathectomy (n = 9), symphysis (n = 47), and thymectomy (n = 3). Tube calibers were 35 (n = 15), 37 (n = 44), 39 (n = 107), and 41 (n = 39). The mean dose area product was 0.0043 mGy.m2 (range, 0.0005–0.035 mGy.m2). For reference, one chest X-ray administers 0.025 mGy.m2. Mean duration of all procedures was 8 minutes (range, 5–35 minutes). We considered procedures with a success at the first attempt and those with a replacement. The deflation of the lung was considered as perfect by the surgeon in all patients (100%).
Auscultation and fluoroscopy results are displayed in Table 1. The clinical auscultation appeared as perfect for 172 out of 205 patients. The fluoroscopy showed an incorrect location for 52 out of 172 patients recognized as clinically perfect. In patients with clinically perfect auscultation, the fluoroscopy showed a hook up parallel to trachea, down parallel to the bronchus, or at an angle made by the hook, and the bronchial channel too acute consequently not perfectly applied over the carina. In patients with an imperfect auscultation, the fluoroscopy found the left channel of the tube located in the right bronchus, the hole at the tip of the tracheal channel in the bronchus (right or left) or the bronchial channel of the tube in the trachea. Consequently, the double lumen tube was in the right position at the first attempt for 120 of 205 only (58.5%). The setting of the double lumen tube was performed with fluoroscopy for 204 out of 205 patients (99.5%). One patient required a fiberscope to replace the double lumen tube.
No ventilation and/or hemodynamic complications were encountered during the anesthesia or surgical procedures.
4. Discussion
Some teams simply use clinical auscultation to control the position of the double lumen tube and the fiberscope is only used in case of clinical problems. Other teams systematically control the position of the double lumen tube with a fiberscope. It is certain that all anesthesiologists involved in managing thoracic surgery should be familiar with this technique. Consequently, the fiberscope has become the reference to perfectly place the double lumen tube.3, 4
However, the main problem with the fiberscope is the learning curve for anesthesiologists, firstly for a safe patient's procedure, secondly to prevent deterioration of the device. Furthermore, several fiberscopes have to be available in case of consecutive thoracic procedures or when the fiberscope is shared with other teams. In case of hemorrhage in the trachea or in bronchus the fiberoptic procedure can become extremely difficult. When the fluoroscopic device is permanently stored in the surgery room, its use is easy.
A different dose area product was given to patients according to procedure duration. The range was between 0.0005 mGy.m2 and 0.035 mGy.m2 and the mean value was 0.0043 mGy.m2. For the fluoroscopic procedure that lasted 35 minutes, the dose given to patients was lower than two chest X-ray examinations. Therefore the technique was completely safe. The reliability was excellent because the double lumen tube was perfectly placed in 99.5% of cases. A specific skill was not required to visually appreciate the left position of the double lumen tube. The fluoroscopic technique can be considered as very efficient. The mean duration of the fluoroscopic procedure was short (8 minutes). Procedures that were a success at the first attempt and procedures requiring multiple attempts were included. In one patient, the procedure lasted 35 minutes because a complete replacement of the double lumen tube was required. The bronchial balloon was not able to maintain the pressure after inflation. That was observed with two double lumen tubes consecutively. Three complete replacements were required. The balloon was probably perforated by a tooth during the introduction in the mouth.
In a retrospective cohort of 20 infants, lung isolation was successfully achieved with fluoroscopy in all patients. The authors concluded that fluoroscopy was a reliable and effective alternative method to the use of the fiberscope for endobronchial intubation in infants.5 The efficiency of the fiberscope to fix the double lumen tube in the right place is not 100%. Authors reported 18 complete failures in a cohort of 1170 patients.6
In our institution we carried out a new protocol in several steps. Firstly, after the placement of the double lumen tube, with a laryngoscope, an initial fluoroscopic image is immediately performed. Secondly, if necessary, the tube is relocated with the help of fluoroscopy (set as explained in Materials and methods). Thirdly, the fiberscope is used in case of fluoroscopy failure. A radiographic image can be kept in the patient file in case of medico-legal dispute.
There are many advantages of fluoroscopy. The visualization of the complete Carlens (left bronchus and hook) is immediate and a whole image of the Carlens is available and stored in the file. Neither specific learning nor training is required to confirm the right position. Furthermore it can be used when the fiberscope has failed to get a clear view in case of hemorrhage in the trachea or in the primary bronchus. No sterilization is required, and it is immediately available for another thoracic procedure or another type of procedure. Fluoroscopy can be easily used in first intention even by anesthesiologists who are not familiar with thoracic surgery.