Sore throat or hoarse voice with bronchial blockers or double-lumen tubes for lung isolation: a randomised, prospective trial.
In a randomised prospective trial conducted in China, we tested the primary hypothesis that endobronchial blockers, including the new Coopdech blocker, would be associated with less sore throat or hoarse voice than double-lumen tubes. Our secondary hypotheses were that endobronchial blockers would differ in the time taken to position and time to lung deflation from that of double-lumen tubes, but would provide similar surgical access.
MATERIALS AND METHODS
We performed this study at Sir Run Run Shaw Hospital, a tertiary referral hospital affiliated with Zhejiang University in Hangzhou, China. The hospital's Research Ethics Committee approved this study and patients gave written informed consent. We approached patients scheduled to have one-lung ventilation for elective video-assisted thoracoscopic surgery. In addition to patients declining to take part, study exclusion criteria included age less than 18 years, obesity, pregnancy, reflux, known or suspected difficult tracheal intubation or pre-existing hoarse voice or sore throat. Patients were blinded to allocation.
Using a table of random numbers, we randomly assigned 120 patients to four groups of 30 patients with different airway devices: Coopdech blocker, Arndt blocker, Univent tube with blocker or double-lumen tube. After patients arrived in the operating room, we applied standard monitoring and placed an arterial cannula and central venous catheter in each patient before inducing anaesthesia. Anaesthesia was induced with intravenous propofol (1 to 2 mg/kg), fentanyl (3 to 5 [micro]g/kg), vecuronium (0.08 to 0.12 mg/kg) and maintained with remifentanil (0.15 to 0.3 [micro]g/kg/min), propofol (4 to 6 mg/kg/h) and inhaled sevoflurane (1.0 to 2.5%) in oxygen. For all patients, the same experienced anaesthetist (TZ) performed tracheal intubation. For males we used an 8.5 mm single-lumen endotracheal tube for the Coopdech and Arndt blockers, or a 7.5 mm Univent endotracheal tube or a 37 Fr or 39 Fr double-lumen tube. For females we used an 8.0 mm single-lumen endotracheal tube for the Coopdech and Arndt blockers, or a 6.5 mm or 7.0 mm Univent endotracheal tube or a 35 Fr or 37 Fr double-lumen tube.
Group airway management
Coopdech group: a standard endotracheal tube with stylet was inserted using direct laryngoscopy, then the Coopdech Endobronchial Blocker (Daiken Medical Company, Osaka, Japan) was advanced through the standard tube. The position of the Coopdech blocker was confirmed with a (flexible fibreoptic) bronchoscope, which had been introduced through a port of the multifunctional connector provided with the blocker.
Arndt group: a standard endotracheal tube with stylet was inserted using direct laryngoscopy, then the wire-guided Arndt endobronchial blocker (Cook Critical Care, Bloomington, Indiana, USA) was advanced through the blocker port of the Arndt multiport adapter. The bronchoscope was introduced through the fibreoptic port and passed through the wire loop. The Arndt blocker was then advanced into the desired mainstem bronchus.
Univent group: The Univent tube (Fuji Corporation, Tokyo, Japan) was inserted using direct laryngoscopy. The endobronchial blocker was advanced through its anterior channel and directed into the right or left mainstem bronchus under vision with a bronchoscope down the main lumen of the Univent endotracheal tube.
Double-lumen tube group: a left double-lumen endotracheal tube (SHER-I-BRONCH, Hudson RCI, Durham, North Carolina, USA) with stylet was introduced using direct laryngoscopy. After the bronchial cuff passed the vocal cords, the stylet was removed and the tube was rotated 90[degrees] toward the left and advanced until slight resistance was encountered. A bronchoscope was used to verify the position of the tube. If malposition was identified, the tube was withdrawn until the endobronchial lumen was above the carina. The bronchoscope was then placed in the endobronchial lumen into the left mainstem bronchus and the tube then advanced over the bronchoscope into the bronchus.
After achieving proper positioning, the tube was covered with a towel to blind the surgeons, who were not present at intubation, to the type of tube. Once satisfactory placement was achieved, the endobronchial cuff of the double-lumen tube or endobronchial blocker cuff was deflated and patients were turned to the lateral decubitus position. Once a patient was in the lateral position, the position of the patient's head was fixed and the endobronchial cuff was inflated, then tube placement was assessed again using bronchoscopy. During surgery, tube position and adequacy of lung collapse were then evaluated clinically every 30 minutes. If lung collapse was not satisfactory, flexible bronchoscopy was used to diagnose and correct the problem.
One-lung ventilation was initiated after the patient was turned to a lateral decubitus position.
A blinded investigator assessed patients for sore throat or hoarse voice in the recovery period and 24 hours after surgery. 'Sore throat or hoarse voice' was defined as a patient who, within the 24 hour period, had sore throat and/or hoarse voice (5), each of which could be mild, moderate or severe (Table 1). 'Postoperative sore throat' was defined as continuous throat pain. 'Hoarse voice' was defined as an acoustic quality that was different from the previous voice quality of the patient. As a supporting secondary outcome the unblinded anaesthetist for the cases used direct laryngoscopy and fibreoptic bronchoscopy for airway injuries. Vocal cord and bronchial injuries were classified into redness, mucosal oedema or haematoma.
Additional secondary outcomes related to time taken to place and position the airway devices.
1. Time required for intubation: the time from the insertion of laryngoscopy until initial placement of the assigned tube.
2. Time required for position: from inserting the bronchoscope until satisfactory placement of the bronchial blocker (Coopdech, Arndt or Univent group) or the endobronchial lumen of the double-lumen tube.
3. Time required for lung collapse: from the start of one-lung ventilation until the lung was completely collapsed. When necessary, two types of manoeuvres were used to facilitate lung collapse. For the double-lumen tube group, a suction catheter was passed into the endobronchial or endotracheal lumen of the non-ventilated lumen and suction applied. For the Coopdech, Arndt or the Univent blockers, suction was attached to the fibreoptic bronchoscope if there was no lung collapse: during that time, the bronchial blocker cuff was deflated, ventilation stopped and after bronchial suction was performed, the bronchial blocker cuff was re-inflated.
The frequency of tube or blocker malpositions was also recorded. 'Malposition' was defined as incorrect main bronchus, inadequate or excessive depth based on bronchoscopic view, auscultation or cuff herniation.
After surgery, overall surgical exposure was rated by the surgical team who were shielded by a cover from the airway device. Surgical exposure was ranked as excellent, fair or poor with the following definitions: excellent=complete collapse with perfect surgical exposure, fair=incomplete collapse not affecting surgical access and poor=partial collapse interfering with surgical access or no collapse.
Based on a previous study from Germany (5), we concluded that a sample size of 30 patients in each group would allow us to detect an absolute reduction of 25% in sore throat or hoarse voice, with a power of 0.8 and a P value of 0.05. Data were analysed using GraphPad Prism Version 4 (GraphPad Software, San Diego, CA, USA). The primary endpoint of number of patients with sore throat or hoarse voice was expressed as a proportion or percentage and demographics and continuous results were expressed as mean [+ or -] standard deviation or median (interquartile range). For our primary end-point we used a 4x2 chi-square test to compare all groups. Post hoc, to confirm that the significantly different group was the double-lumen tube group, we used a 3x2 chi-square to compare the blocker groups. Having found no statistical difference between the blocker groups, we then used Fisher's exact tests to compare the double-lumen tube group to the blocker groups. Among our secondary endpoints, because the times for intubation, positioning and lung collapse were not normally distributed in some groups, we used Kruskal-Wallis tests (9). We compared the double-lumen group to the blocker groups using a Bonferroni procedure for multiple testing (9). P values <0.05 were considered significant.
We studied 120 adult patients aged from 18 to 80 years with American Society of Anesthesiologists physical status I to III (Table 2). The four groups of 30 patients were similar and underwent of video-assisted thoracic surgery, predominantly lung surgery, requiring both left and right lung isolation (Table 2). The incidence and severity of sore throat or hoarse voice was less in the blocker groups than double-lumen tube group: Coopdech 13%, Arndt 20%, Univent 30% and double-lumen tube 60%, (P <0.001, Figure 1). The three blocker groups however, did not significantly differ (P=0.28). The incidence of sore throat or hoarse voice in the double-lumen tube group was 47% greater than the Coopdech group (95% CI 25 to 64%, P <0.001), 40% greater than the Arndt group (95% CI 15 to 65%, P <0.003) and 30% greater than the Univent group (95% CI 5 to 55%, P=0.04).
[FIGURE 1 OMITTED]
The pattern of severity of sore throat or hoarse voice also differed (Figure 1). Among the 90 patients in the blocker groups, 16 patients (18%) had mild sore throat or hoarse voice while three patients (3%) had moderate or severe sore throat or hoarse voice. In contrast, among the 30 patients in the double-lumen tube group, 11 patients (37%) had mild sore throat or hoarse voice and seven (23%) had moderate or severe sore throat or hoarse voice. These findings are consistent with the pattern of observed airway injuries, an unblinded secondary endpoint (Table 3). Tracheal intubation was successful in all patients in all four groups. The double-lumen tubes took longer for intubation and placement but less time for lung collapse than the blockers (Table 3). The number of patients with malpositions was similar between the groups (Table 3). The surgical exposure was similar between the groups with more than 80% of patients in each group having excellent exposure, but no group had excellent surgical exposure for all patients (Table 3).
In this randomised study of Chinese patients undergoing video-assisted thorascopic surgery, we found that when compared to double-lumen endotracheal tubes, endobronchial blockers (blockers) were associated with less sore throat or hoarse voice. Further, the blockers took less time to position but took longer for lung collapse. After lung collapse however, the endoscopic surgical access was comparable between the double-lumen tube group and the blocker groups. The new Coopdech blocker (4) appears comparable with the established Arndt (2) and Univent blockers (1,3).
Theses findings are consistent with the design features of the different airway devices. Bronchial blockers require single-lumen endotracheal tubes either independent of the blocker with the Arndt (2) and Coopdech (4) blockers or integrated with the Univent (1,3). A single-lumen tube will have a smaller diameter than a double-lumen tube for the same patient (1). Single-lumen tubes are both easier to place, including during rapid sequence induction and intubation, and less likely to cause trauma than a double-lumen tube (1). A double-lumen tube, however, has a large lumen allowing more rapid lung deflation. Another advantage of the Coopdech and Arndt blockers is that the blockers and their adaptors can be removed at the end of the case, facilitating postoperative ventilation if required. In contrast, double-lumen tubes and integrated Univent blocker tubes are usually exchanged for a single-lumen endotracheal tube for postoperative ventilation (1).
The overall design of this study was based on that of Knoll et al (5), one of the few studies comparing sore throat or hoarse voice with different endotracheal tubes. Knoll et al compared sore throat or hoarse voice with a double-lumen tube or Arndt blocker in two groups of 30 patients in a German hospital. They found that five patients (17%) had sore throat or hoarse voice in an Arndt group and 12 patients (44%) in a double-lumen tube group. This is comparable to the rates of sore throat or hoarse voice in our study, 20% in the Arndt group and 60% in the double-lumen tube group, with Chinese patients who were smaller than the patients in the study by Knoll et al (5). Further, like us, Knoll et al found that none of the patients had rare major complications such as bronchial rupture or vocal cord paralysis.
Our secondary endpoints included the time taken to position airway devices and were derived from the approach used by Campos et al (6) who compared left-sided double-lumen tubes with Arndt and Univent blockers. Like us, they found that lung deflation was faster with double-lumen tubes but contrary to us they found that blockers, particularly Arndt blockers, took longer to position. Ethnic differences between the patient groups in each study may be a factor (7,8). In another study in minimally invasive cardiac surgery, Grocott et al (10) found that double-lumen tubes required more attempts at laryngoscopy but provided better surgical conditions. As in our study however, both Campos et al (6) and Grocott et al (10) found that positioning each of the devices took less than five minutes (6). Further, as in our study, the number of intraoperative malpositions and surgical exposure was similar between the double-lumen tube and blocker groups.
This study has the strengths that the primary end point of sore throat or hoarse voice was assessed by a blinded observer in patients randomised to airway device allocation. The study also has several limitations. First, the primary endpoint includes patient reports of sore throat. Second, this is a single-centre study where blinding was limited, in part, due to the procedural nature of the interventions. Further, as with other studies (5) a single, experienced, anaesthetist performed all intubations. This limits the generalisability of the study because less experienced anaesthetists have greater difficulty in placing both double-lumen tubes and bronchial blockers (11). Conversely, our results could be influenced by any biases of the unblinded anaesthetist. Further, although the differences between the blocker groups were not statistically significant, because the groups were fairly small the possibility of clinically important differences cannot be completely excluded.
In summary, for Chinese patients we found that double-lumen tubes produce substantially more sore throat or hoarse voice than bronchial blockers, including the new Coopdech blocker (4), but that operating conditions are similar. These results are comparable with the few studies conducted in North America and Europe (5,6). Given this association with less sore throat or hoarse voice, and possible advantages with more difficult intubations (1), we conclude that anaesthetists might consider gaining the experience necessary to use bronchial blockers (1,11).
Accepted for publication on January 20, 2009.
(1.) Campos JH. Which device should be considered the best for lung isolation: double-lumen endotracheal tube versus bronchial blockers? Curr Opin Anaesthesiol 2007; 20:27-31.
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(6.) Campos JH, Kernstine KH. A comparison of a left-sided Broncho-Cath with the torque control blocker univent and the wire-guided blocker. Anesth Analg 2003; 96:283-289.
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(8.) Chong DY, Greenland KB, Tan ST, Irwin MG, Hung CT. The clinical implication of the vocal cords-carina distance in anaesthetized Chinese adults during orotracheal intubation. Br J Anaesth 2006; 97:489-495.
(9.) Myles PS, Gin T. Statistical methods for anaesthesia and intensive care. Oxford: Butterworth-Heinemann 2000.
(10.) Grocott HP, Darrow TR, Whiteheart DL, Glower DD, Smith MS. Lung isolation during port-access cardiac surgery: double-lumen endotracheal tube versus single-lumen endotracheal tube with a bronchial blocker. J Cardiothorac Vasc Anesth 2003; 17:725-727.
(11.) 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 control blocker, and Arndt wire-guided endobronchial blocker. Anesthesiology 2006; 104:261-266.
T. ZHONG *, W. WANG ([dagger]), J. CHEN ([double dagger]), L. RAN ([section]), D. A. STORY **
Department of Anesthesiology, Sir Run Run Shaw Hospital, Hangzhou, China
* M.D., Ph.D., Director, Department of Anesthesiology, Sir Run Run Shaw Hospital, Medical College, Zhejiang University.
([dagger]) M.D., Resident, Department of Anesthesiology, Sir Run Run Shaw Hospital, Medical College, Zhejiang University.
([double dagger]) M.D., Fellow, Department of Anesthesiology, Sir Run Run Shaw Hospital, Medical College, Zhejiang University.
([section]) M.D., Ph.D., Fellow, Department of Anesthesiology, Sir Run Run Shaw Hospital, Medical College, Zhejiang University.
** M.B., B.S., B.Med.Sci., M.D., F.A.N.Z.C.A., Head of Research, Department of Anaesthesia, Austin Health and Associate Professor, Department of Surgery, University of Melbourne, Heidelberg, Victoria, Australia.
Address for reprints: Associate Professor D. A. Story, Department of Anaesthesia, Austin Hospital, Studley Rd, Heidelberg, Vic. 3084.
TABLE 1 Airway complication classification Slight Moderate Severe Sore throat Slight to moderate Slight to moderate Moderate to or hoarse sore throat, with sore and/or slight severe sore no hoarse voice to moderate hoarse throat and/ <24 h voice <24 h or moderate to severe hoarse voice >24 h Bronchial Redness Oedema Haematoma injuries Vocal cord Thickening of Oedema Haematoma injuries vocal cords Redness Erythema Granuloma TABLE 2 Demographic data Coopdech Arndt Number 30 30 Age, y * 61 [+ or -] 8 63 [+ or -] 8 Height, cm * 168 [+ or -] 7 167 [+ or -] 8 Weight, kg * 60 [+ or -] 9 63 [+ or -] 9 gender, M/F 17/13 19/11 Anaesthesia (min) ([dagger]) 160 (100-360) 170 (95-330) Operation side, left/right 12/18 11/19 Univent Double-lumen Number 30 30 Age, y * 61 [+ or -] 9 64 [+ or -] 8 Height, cm * 169 [+ or -] 7 168 [+ or -] 7 Weight, kg * 65 [+ or -] 9 60 [+ or -] 10 gender, M/F 20/10 17/13 Anaesthesia (min) ([dagger]) 155 (90-350) 165 (90-310) Operation side, left/right 9/21 14/16 * Mean [+ or -] standard deviation, ([dagger]) Median (interquartile range). TABLE 3 Time taken to place and position the airway devices, malpositions, surgical exposure and observed airway injuries Coopdech Arndt Number 30 30 30 Intubation, min * 1.1 (0.9-1.3) ([dagger]) 1.0 (0.8-1.2) ([dagger]) Position, min * 0.9 (0.8-1.1) ([dagger]) 2.5 (1.5-3.0) ([dagger]) Lung collapse, min * 12.4 (8.6-14.9) ([dagger]) 13.4 (10.3-15.9) ([dagger]) Malpositions, n 7 11 Surgical exposure Excellent/fair/poor 27/3/0 26/3/1 Observed airway injuries, n Slight/moderate/severe 3/0/0 4/0/1 Univent Double-lumen Number 30 30 30 Intubation, min * 1.4 (0.9-1.8) ([double 1.8 (1.3-2.2) dagger]) Position, min * 1.0 (0.7-1.3) ([dagger]) 4.3 (3.4-5.4) Lung collapse, min * 11.9 (8.8-14.8) ([dagger]) 6.7 (3.7-9.8) Malpositions, n 8 8 Surgical exposure Excellent/fair/poor 24/5/1 26/4/0 Observed airway injuries, n Slight/moderate/severe 6/1/2 9/3/1 * Median (interquartile range), ([dagger]) Different from double-lumen tube, P <0.05, ([double dagger]) Not different from double-lumen, P tube, >0.05.
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|Author:||Zhong, T.; Wang, W.; Chen, J.; Ran, L.; Story, D.A.|
|Publication:||Anaesthesia and Intensive Care|
|Date:||May 1, 2009|
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