Left-sided Double-lumen Tube Research Articles

Performance Comparison of Right- and Left-Sided Double-Lumen Tubes Among Infrequent Users

To compare performance of right- versus left-sided double-lumen tubes (DLTs) among infrequent users by evaluating the incidence and severity of hypoxemia, hypercapnia, and high airway pressures. A retrospective, cohort study. A university hospital. Ninety-eight patients undergoing left-sided DLT placement (53.9 +/- 21.2 years old) and 98 patients undergoing right-sided DLT placement (62.3 +/- 20.6 years old). Cases performed by thoracic anesthesia specialists were excluded. The authors retrospectively reviewed electronic anesthetic records from a 2-year period to determine the incidence and severity of hypoxia (SpO(2) < 90%), hypercapnia (end-tidal carbon dioxide > 45 mmHg) and high airway pressures (peak inspiratory pressure >35 cmH(2)O) during one-lung ventilation via right and left DLTs. Right-sided (n = 98) DLTs were almost exclusively used on the side contralateral to surgery by infrequent users, whereas left-sided (n = 98) DLTs were used for ipsilateral surgery one third of the time. Hypoxia lasted longer in left versus right DLTs, but the frequency of hypoxia was the same for each tube type among infrequent users. Hypercapnia and high airway pressures occurred more frequently with left-sided DLTs. Left-sided DLTs are perceived to be safer because they may be less prone to malpositioning during lung isolation. However, the supposition that left-sided DLTs are safer than right-sided DLTs when intraoperative hypoxia, hypercapnia, and high airway pressures are used as criteria, even when these tubes are used by infrequent users, is not supported by the data.

One-lung ventilation in a patient with tracheobronchomegaly: a case report and literature review

One-lung ventilation in a patient with tracheobronchomegaly: a case report and literature review

Double-Lumen Tube Placement Using a Retractable Carinal Hook: A Preliminary Report

Proper placement of a double-lumen tube (DLT) is vital for its optimal functioning. We modified the standard blind method of left-sided DLT placement using a retractable carinal hook. The aim of this study was to determine whether this modified method could improve the success rate of correct initial tube positioning compared with the conventional method. Forty patients scheduled for general anesthesia requiring left-sided DLTs in a prospective, randomized, controlled trial were studied. The incidence of malpositions and time required for proper placement of a DLT using either the conventional method (conventional group, n = 20) or a modified method using a retractable carinal hook (hook group, n = 20) were recorded. The hook is a modified gum elastic bougie. Correct positioning was confirmed by fiberoptic bronchoscopy (FOB). After initial DLTs placement, clinical finding alone detected malpositions in 3 of 20 (15%) and 1 of 20 (5%) patients in the conventional and hook groups, respectively. Subsequent FOB revealed a significantly lower incidence of tube malposition in the hook group 2 of 20 (10%), compared with the conventional group 9 of 20 (45%) (P = 0.03). The time for clinical placement of DLTs was comparable in the two groups (P = 0.63), and the time for FOB confirmation and adjustment was significantly shorter in the hook group (88.9 +/- 35.7 s) compared with the conventional group (152.3 +/- 40.3 s) (P < 0.0001). The use of a retractable carinal hook increased the success rate and shortens the time for correct DLT positioning. Further, larger studies are required to confirm its safety and reliability.

Gradient of bronchial end-tidal CO2 during two-lung ventilation in lateral decubitus position is predictive of oxygenation disorder during subsequent one-lung ventilation

Hypoxemia is one of the major problems during one-lung ventilation (OLV). During two-lung ventilation (TLV) using a double-lumen bronchial tube, bronchial endtidal carbon dioxide partial pressure (ETbr(CO2)) can be determined on both sides, independently. The ETbr(CO2) is mainly dependent on the pulmonary perfusion to each lung. If the degree of oxygenation disorder during OLV were to be predictable before starting OLV, this could provide time to prepare for any subsequent hypoxemia. The aim of this study was to investigate whether the difference of ETbr(CO2) (D-ETbr(CO2)) between the dependent and the nondependent lungs during TLV in the lateral decubitus position (LP) could be a predictive factor for the severity of oxygenation disorder under subsequent OLV. Eighteen patients undergoing lung surgery were enrolled in this study. Anesthesia was induced with intravenous thiopental and fentanyl, supplemented by the inhalation of sevoflurane. A left-sided double-lumen bronchial tube was placed. The ETbr(CO2) was independently determined on each side during TLV in the supine position (SP) and at 10 min after changing the position from SP to LP. PaO2/inspiratory fraction of oxygen (FIO2) was taken at 15 min after switching from TLV to OLV in LP. The decrease of PaO2/FIO2 at 15 min during OLV in LP correlated with the reduction of the D-ETbr(CO2) predetermined during TLV in LP (r = 0.698; P < 0.01). The D-ETbr(CO2) predetermined during TLV in LP could be a predictive factor for the severity of oxygenation disorder after starting OLV in LP.

Choosing a Lung Isolation Device for Thoracic Surgery: A Randomized Trial of Three Bronchial Blockers Versus Double-Lumen Tubes

There is no consensus on the best technique for lung isolation for thoracic surgery. In this study, we compared the clinical performance of three bronchial blockers (BBs) available in North America with left-sided double-lumen tubes (DLTs) for lung isolation in patients undergoing left-sided thoracic surgery. One hundred four patients undergoing left-sided thoracotomy or video-assisted thoracoscopic surgery were randomly assigned to one of the four lung isolation groups (n = 26/group). Lung isolation was with an Arndt wire-guided BB (Cook Critical Care, Bloomington, IN), a Cohen Flexi-tip BB (Cook Critical Care) or a Fuji Uni-blocker (Fuji Systems, Tokyo) or with a left-sided DLT (Mallinckrodt Medical, Cornamadde, Athlone, Westmeath, Ireland). Anesthetic management and lung isolation were performed according to a standardized protocol. Each group was randomly subdivided into two subgroups (n = 13/subgroup): immediate suction (at the time of insertion of the lung isolation device) (Subgroup I) or delayed suction (20 min after insertion of the lung separation device) (Subgroup D) according to when suction was applied to the BB suction channel or the bronchial lumen of the DLT. Using a verbal analog scale, lung collapse was assessed by the surgeons, who were blinded to the lung isolation technique. There was no difference among the lung isolation devices in lung collapse scores at 0 (P = 0.66), 10 (P = 0.78), or 20 min (P = 0.51) after pleural opening. The time to initial lung isolation was less for DLTs (93 +/- 62 s) than BBs (203 +/- 132) (P = 0.0001). There were no differences among the BBs in the time to lung isolation (P = 0.78). There were significantly more repositions after initial placement of the lung isolation device with BBs (35 incidents) than with DLTs (two incidents) (P = 0.009). The Arndt BB required repositioning more frequently (16 incidents) than the Cohen BB (8) or the Fuji BB (11) (P = 0.032). The three BBs provided equivalent surgical exposure to left-sided DLTs during left-sided open or video-assisted thoracoscopic surgery thoracic procedures. BBs required longer to position and required intraoperative repositioning more often. The Arndt BB needed to be repositioned more often than the other BBs.

Anaesthesia for serial whole-lung lavage in a patient with severe pulmonary alveolar proteinosis: a case report

IntroductionPulmonary alveolar proteinosis is a rare condition that requires treatment by whole-lung lavage. We report a case of severe pulmonary alveolar proteinosis and discuss a safe and effective strategy for the anaesthetic management of patients undergoing this complex procedure.Case presentationA 34-year-old Caucasian man was diagnosed with severe pulmonary alveolar proteinosis. He developed severe respiratory failure and subsequently underwent serial whole-lung lavage. Our anaesthetic technique included the use of pre-oxygenation, complete lung separation with a left-sided double-lumen endotracheal tube, one-lung ventilation with positive end-expiratory pressure, appropriate ventilatory monitoring, cautious use of positional manoeuvres and single-lumen endotracheal tube exchange for short-term postoperative ventilation.ConclusionPatients with pulmonary alveolar proteinosis may present with severe respiratory failure and require urgent whole-lung lavage. We have described a safe and effective strategy for anaesthesia for whole-lung lavage. We recommend our anaesthetic technique for patients undergoing this complex and uncommon procedure.

The Effects of Intravenous Hyperoxygenated Solution Infusion on Systemic Oxygenation and Intrapulmonary Shunt During One-Lung Ventilation in Pigs

Many anesthetic methods have been applied to maintain acceptable oxygenation during one-lung ventilation (OLV). However, the optimal management has not been definitely determined. The aim of this study was to investigate whether intravenous hyperoxygenated solution (HOS) infusion would improve systemic oxygenation and reduce intrapulmonary shunt during OLV. Sixteen pigs (25-35 kg) were anesthetized, tracheally intubated, and mechanically ventilated. After placement of femoral artery and pulmonary artery catheters, a left-sided double-lumen tube (DLT) was placed via tracheotomy. The animals were allocated randomly to one of the two study groups (n = 8 each); control group (C group) and hyperoxygenated solution group (H group). Animals in H group received intravenous HOS infusion immediately after the beginning of OLV via internal right jugular vein with an infusion pump, and the rate of infusion was 15 mL.kg(-l).h(-l); and in C group, the same amount of lactate Ringer's solution (LRS) was used in place of HOS. Arterial and venous blood gases analysis were recorded in three phases: during two-lung ventilation just before beginning OLV (TLV), 30 min after beginning OLV (OLV + 30), and 60 min after beginning OLV (OLV + 60). We measured arterial oxygen saturation (SaO(2)), mixing venous oxygen saturation (S(V)O(2)), partial pressure of arterial oxygen (PaO(2)), partial pressure of mixing venous oxygen (PvO(2),) oxygen contents in systemic arterial and mixed venous blood (CaO(2), CvO(2)), and venous admixture percentage (Qs/Qt%). Heart rate (HR), mean arterial pressure (MAP), mean pulmonary artery pressure (MPAP), and cardiac output (CO) were also recorded. After 30 and 60 min OLV, there was a significant decrease in PaO(2), SaO(2), PvO(2), SvO(2), CaO(2), and CvO(2), and a significant increase of Qs/Qt% in both groups (P < 0.01). The values of PaO(2), SaO(2), PvO(2), SvO(2), and CvO(2) in H group at both OLV + 30 and OLV + 60 were significantly higher than those in C group (P < 0.05, P < 0.01). Although the values of CaO(2) in H group were higher than those in C group at OLV + 30 and OLV + 60, there were no significant differences. Comparing the values of Qs/Qt% between the two groups at OLV + 30 and OLV + 60, there were also no significant differences. Intravenous HOS infusion led to minimal changes in intrapulmonary shunt, nevertheless, it could ameliorate arterial oxygenation obviously during OLV. This might be a new strategy to improve systemic oxygenation during OLV.

In Response:

Drs. Lohser and Brodsky1 raise the measurement of left mainstem bronchial diameter as an indicator of proper sizing for left-sided double-lumen tubes (DLT), and suggest that use of this technique in our recent study may have yielded different results. While we don't question the mathematical formulas, none of the clinicians involved in the study practice this method despite over 80 years of cumulative experience successfully placing DLT in an institution where >2000 thoracic procedures are performed each year. Accordingly, our work addressed the prevalent practice at our institution of sizing DLT by height and/or gender. Although the participating anesthesiologists were all initially trained to use conventional methods at a time when fiberoptic bronchoscopy was not readily available, the strength of our study design is that we compared outcomes in a single clinical setting between anesthesiologists whose practice now differs.2 Our data showed that in regard to intraoperative end-points reflecting the adequacy of lung collapse and preservation of oxygenation, both our “conventional” approach and intentional downsizing are comparable. While we appreciate the interpretation by Drs. Lohser and Brodsky that our observed “failure to isolate” temporarily may well have been due to undersized DLT, we maintain our stated conclusion that malposition was responsible.2 With respect to the rare event of DLT causing airway damage, the authors cite their own early data indicating that rupture in particular is most frequently associated with small DLT,3 perhaps due to the need for relative cuff hyperinflation. While we included this citation in our manuscript, we also included references indicating the possibility of trauma from either small or large DLT,4–6 a risk also previously noted by Brodsky and Lemmens7 and cited in our paper. Furthermore, despite use of down-sized DLT we rarely found that more than 3 mL was required to provide an adequate seal. The authors further point to the theoretical increase in auto-PEEP due to downsizing of DLT. While experimental studies have clearly shown differences in the gas flow characteristics between large and small DLT, neither results of the our study nor our extensive clinical experience have given any indication that the 0.6 mm difference between a 35 and 39 FR internal diameter has had any deleterious effects in our patient population. Indeed, our reported incidence of intraoperative hypoxemia and recently published incidence of acute lung injury in 1,428 patients undergoing lung resection are low and consistent with the literature.8 David Amar, MD Paul M. Heerdt, MD, PhD Dawn P. Desiderio, MD Anne C. Kolker, MD Departments of Anesthesiology and Critical Care Medicine, and Surgery, Clinical Memorial Sloan-Kettering Cancer Center and Weill Medical College of Cornell University New York, NY [email protected]

CASE 4—2008: Difficult Weaning From Cardiopulmonary Bypass in the Lateral Position Caused by Lung Collapse

ATRIAL SEPTAL DEFECTS (ASDs) are usually repaired through a median sternotomy under general anesthesia and cardiopulmonary bypass (CPB). However, a right anterolateral thoracotomy1 or right-limited posterior thoracotomy2 approach can be used for cosmetic reasons for closure of an ASD. The anesthetic management is similar to any other cardiac surgical procedure; however, tracheal intubation with a left-sided double-lumen endobronchial tube (DLT) is preferred (if feasible) to permit collapse of the right lung and to facilitate surgical exposure.

Right- and Left-Sided Mallinckrodt Double-Lumen Tubes Have Identical Clinical Performance

Left-sided double-lumen tubes are perceived to be safer than right-sided tubes, because they may be less prone to malposition. If this is true, then the incidence and severity of hypoxemia, hypercapnea, and high airway pressures should be higher for right-sided tubes during thoracic surgery than for left-sided tubes. We retrospectively reviewed thoracic surgical anesthetics between April 15, 2003, and December 31, 2004, using an automated anesthesia information management system. The system automatically records pulse oximetry, end-tidal carbon dioxide, and peak inspiratory pressure data every 30 s. Side of surgery and double-lumen tube placement are also documented. We compared the frequency of right- and left-sided Mallinckrodt tube use by thoracic anesthesiologists. Next, we examined the incidence, duration, and severity of hypoxemia (Spo(2) <90%), hypercapnea (Etco(2) >45 mm Hg) and high airway pressures (peak inspiratory pressure >35 cm H(2)O) for lung and chest wall surgery patients. Group counts and means were compared by standard statistical methods. Right- (n = 241) and left- (n = 450) sided tubes were almost exclusively used on the side contralateral to surgery. There were no differences in the incidence or duration of hypoxemia, hypercarbia, or high airway pressures. There was a small but significant increase in Etco(2) for patients having left lung ventilation. The supposition that left-sided double-lumen tubes are safer than right-sided tubes when intraoperative hypoxemia, hypercapnea, and high airway pressures are used as criteria for safety is not supported by our data comparing the two types of tubes from one manufacturer.

Can ultrasound be useful for predicting the size of a left double-lumen bronchial tube? Tracheal width as measured by ultrasonography versus computed tomography

Study Objective To correlate tracheal width as measured by ultrasound with width measured by computed tomography (CT), and to evaluate the possible role of ultrasound in the selection of the proper size of left-sided double-lumen endotracheal tubes (LDLTs). Design Two independent, prospective, observational clinical studies (Study 1 and Study 2). Setting University hospital. Patients Study 1 included 25 patients and Study 2 included 20 adult thoracic surgery patients who required a LDLT during anesthesia. Interventions and Measurements In Study 1, CT measurements of tracheal width were made at the coronary plane 0.5 cm above the sternoclavicular joint; CT measurements of the left main bronchus diameter were made 1 cm below the carina. Ultrasound measurement of tracheal width was performed just above the sternoclavicular joint in the transversal section. In Study 2, patients' tracheas were intubated with a LDLT based on ultrasound measurements. The frequencies of incorrect selections of LDLT and unsatisfactory lung collapse were analyzed. Main Results There was a strong correlation between tracheal width as measured by ultrasound and tracheal width ( r = 0.882, P < 0.001) and left main bronchus width ( r = 0.832, P < 0.001) as measured by CT. In 5 cases (25%), the incorrect LDLT by ultrasound was selected; and one (5%) was found to have an unsatisfactory lung collapse. Conclusion Measurement of the outer tracheal width by ultrasound can be a useful method for predicting the diameter of left main bronchus and for selecting a LDLT.

Tension Pneumothorax During One-Lung Ventilation

In Response: Our intent in submitting this case report was to highlight the pathophysiology and early clinical signs of a tension pneumothorax in the setting of an open contralateral thorax. Dr. Lohser1 reiterates established literature that defines the challenges confronted with lung isolation with a right-sided double-lumen tube (DLT). Experienced clinicians can safely institute functional lung isolation without the assistance of fiberoptic bronchoscopy with a left-sided DLT.2 The greater margin of safety with a left-sided DLT is due to the distal take-off of the left upper lobe orifice.3 We agree that successful placement of a right-sided DLT requires fiberoptic bronchoscopy and visualization of a patent right upper lobe orifice.4 DLT malposition is commonly responsible for increasing airway pressures during one lung ventilation. However, bronchospasm, secretions, dynamic hyperinflation, and pneumothorax must also be considered as potential causes. Fixating attention on just tube malposition may distract from the diagnosis and delay timely treatment of these other serious causes. The “classic” presentation of a tension pneumothorax during an open thoracotomy is herniation of the mediastinum into the operative field. This phenomenon was not observed in our patient. From the surgeon's vantage this case appeared as a failure of lung isolation since “normal” appearing lung obscured the operative field. Displacement of the mediastinum would only be appreciated if the operative lung was collapsed and the open hemithorax inspected before the pneumothorax expanded. In our case with its unique presentation, the risk of significant complications from decompressing the contralateral pleural space with a needle directed through the operative field (e.g., normal lung) would have been unacceptable. Gordon N. Finlayson, MD, FRCP Jay B. Brodsky, MD Department of Anesthesia Stanford University School of Medicine Stanford, California [email protected]

Comparison of two methods for assessment of size and depth of left-sided double-lumen traqueal tubes

Comparison of two methods for assessment of size and depth of left-sided double-lumen traqueal tubes

Effects of Arginine Vasopressin on Oxygenation and Haemodynamics during One-Lung Ventilation in an Animal Model

In a case of arterial hypotension during one-lung ventilation, haemodynamic support may be required to maintain adequate mean arterial pressure. Arginine vasopressin, a potent systemic vasoconstrictor with limited effects on the pulmonary artery pressure, has not been studied in this setting. Twelve female pigs were anaesthetised and ventilated and arterial, central venous and pulmonary artery catheters were inserted. A left-sided double lumen tube was placed via tracheostomy and one-lung ventilation was initiated. The animals were in the left lateral position, with the left lung ventilated and right lung collapsed. Respiratory and haemodynamic values were recorded before and during a continuous infusion of arginine vasopressin sufficient to double the mean arterial pressure. The arginine vasopressin caused a decrease in cardiac output (3.8+/-1.1 vs. 2.7+/-0.7 l/min, P <0.001) and mixed-venous oxygen tension (39.1+/-5.8 vs. 34.4+/-5 mmHg, P=0.003). Pulmonary artery pressure was unchanged (24+/-2 vs. 24+/-3 mmHg, P=0.682). There was no effect of the arginine vasopressin on arterial oxygen tension (226+/-106 vs. 231+/-118 mmHg, P=0.745). However, there was a significant decrease in shunt fraction (28.3+/-6.2 vs. 24.3+/-7.8%, P=0.043) and a significant proportional increase in perfusion of the ventilated lung (78.8+/-9.5 vs. 85.5+/-7.9%, P=0.036). In our animal model of one-lung ventilation, doubling mean arterial pressure by infusion of arginine vasopressin significantly affected global haemodynamics, but had no influence on systemic arterial oxygen tension.

Isolation of the Right Upper-Lobe with a Left-Sided Double-Lumen Tube After Left-Pneumonectomy

A patient with a prior left pneumonectomy required surgical drainage of a right upper lobe aspergilloma. A left double-lumen endobronchial tube was placed in the right bronchus intermedius, isolating the right upper lobe while allowing ventilation of the right middle and lower lobes.

Modified right-sided Broncho-Cath™ double lumen tube improves endobronchial positioning: a randomized study

ObjectiveA left-sided double lumen tube is recommended for one-lung ventilation for most thoracic surgeries, but for certain indications, a right-sided double lumen tube (R-DLT) may be mandatory. Frequent malposition of R-DLTs has been reported. We propose an innovative modification of Mallinckrodt’s Broncho-Cath™ R-DLT consisting of an enlarged area of the lateral orifice, and studied the impact of this modification on the adequacy of R-DLT positioning.MethodsEighty adult patients scheduled for elective thoracic surgery were randomized into two groups: standard Broncho-Cath™ R-DLT, or modified Broncho-Cath™ R-DLT. After induction of anesthesia, the R-DLT was positioned using a fibreoptic bronchoscope. The position of the R-DLT was assessed on three occasions: with the patient supine (T1), then immediately following the patient’s transfer to the lateral position (T2), and after repositioning of the tube, when needed, with the patient in lateral position (T3). A score ranging from 1 to 4 was accorded to the relative position of the right upper lobe (RUL) orifice in relation to the origin of the RUL bronchus.ResultsThe modified Broncho-Cath™ R-DLT was more frequently in an adequate position at T2: 77% vs 37% of patients (P = 0.0121), and easier to reposition at T3: 97% vs 74% of patients (P = 0.0109) in comparison to the standard Broncho-Cath™ R-DLT group.ConclusionThese data suggest the superiority of the modified Broncho-Cath™ R-DLT compared to a standard Broncho-Cath™ R-DLT for optimal R-DLT positioning to facilitate one-lung ventilation during thoracic surgery.

Results of the Study Comparing Devices Used for Lung Isolation Are Rather Concerning

Results of the Study Comparing Devices Used for Lung Isolation Are Rather Concerning

Effects of inhaled nitric oxide on oxygenation and haemodynamic performance during one-lung ventilation in pigs

AbstractObjective: To study the effects of 20 ppm inhaled nitric oxide (iNO) on haemodynamics and systemic oxygenation during one-lung ventilation (OLV) in vivo. Design: Prospective animal study with a cross-over design. Setting: Animal laboratory of a university hospital. Subjects: Eight female pigs. Outcome measures: The pigs were anaesthetized, tracheally intubated, and mechanically ventilated. Following placement of femoral arterial and pulmonary artery catheters, a left-sided double-lumen tube (DLT) was placed via tracheotomy After DLT placement, in each animal OLV was performed during intravenous anaesthesia in a cross-over design with and without iNO (20ppm) in 100% oxygen. After haemodynamic stabilization, haemodynamic measurements and blood gas analyses were made, in addition we measured differential lung perfusion with colored microspheres in three animals. Results and Conclusions: iNO did not improve oxygenation nor did iNO reduce pulmonary arterial pressure in our animal model. Mixed venous Pv...

Devices for Lung Isolation Used by Anesthesiologists with Limited Thoracic Experience

Lung isolation is accomplished with a double-lumen tube or a bronchial blocker. Previous studies comparing lung isolation methods were performed by experienced anesthesiologists in thoracic anesthesia. Therefore, the results of these studies may not be relevant to the anesthesiologist with limited experience. This study compared the success rates of lung isolation devices among anesthesiologists with limited experience in thoracic anesthesia. A prospective, randomized trial was designed to determine the success and time required for proper placement of the left-sided double-lumen tube (n = 22), the Univent tube (Vitaid Ltd., Lewiston, NY; n = 22), and the Arndt Blocker (Cook Critical Care, Bloomington, IN; n = 22). Anesthesiologists with less than two lung isolation cases per month were included (faculty n = 17 and senior residents n = 11). Variables recorded included (1) successful placement (as determined by an independent observer), (2) time of placement, and (3) the number of times the fiberoptic bronchoscope was used. Participants failed to place or position their assigned device in 25 of 66 patients (failure was 39% among faculty and 36% among senior residents). The failure rate did not differ among the three devices (P = 0.65). The median (25th-75th percentile) times to complete the placement procedures were as follows: (1) double-lumen tube: 6.1 min (4.6-9.5 min), (2) Univent tube: 6.7 min (4.9-8.8 min), and (3) Arndt Blocker: 8.6 min (5.8-17.5 min) (P = 0.45 comparing all devices). After device malposition was identified, it took 1 min or less for the investigating anesthesiologist to achieve optimal position. Anesthesiologists with limited experience in thoracic anesthesia frequently fail to successfully place lung isolation devices. Rapid successful device placement by an experienced anesthesiologist excluded any contribution of uniquely difficult anatomy. The nature of the malpositions suggests that the most critical factor in successful placement was the anesthesiologist's knowledge of endoscopic bronchial anatomy.

Optimal depth of insertion of left-sided double-lumen endobronchial tubes cannot be predicted from body height in below average-sized adult patients

The optimal depth of insertion of left-sided double-lumen endobronchial tubes is strongly correlated with body height in average-sized adults. However, this relationship has not been studied in below average-sized adult patients. We investigated whether or not there is a clinically useful relationship in below average-sized adult patients. One hundred and ninety six consecutive adult patients undergoing thoracic surgery under one-lung anaesthesia (body height < or = 155 cm) were included in this study. Left-sided double-lumen tubes were inserted under the guidance of a fibre-optic bronchoscope. Optimal depth was defined as the proximal surface of the bronchial cuff positioned just below the carina. There was a statistically significant positive correlation between body height and the optimal depth of insertion (r = 0.61, P < 0.0001); however, the correlation coefficient was low. The actual optimal depth of insertion of one patient was even 4.5 cm shorter than that obtained from the equation. Although there was a statistically significant correlation between body height and the optimal depth of insertion of left sided double lumen tubes in adult patients of short stature (< or = 155 cm), clinical application of the equation is not warranted and these tubes should be inserted under direct vision with a fibre-optic bronchoscope.