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General Article

CASE REPORT

Left Mainstem Bronchial Intubation at an ExtremelyShort Incisor-to-Carina Distance in a Patient withSevere Ascites

Alyssa B. Brzenski, MD, and Jonathan L. Benumof, MD

Unintentional left mainstem bronchial intubation after direct laryngoscopy is less commonthan unintentional right mainstem bronchial intubation, having only been referenced 3 timesoutside of the anesthesia literature. We report a case of unintentional left mainstem intubationat an extremely short incisor-to-carina distance. We hypothesize that the left mainstemintubation occurred because of a distortion of the anatomy of the tracheal bifurcation, caused by the patient’s severe ascites, hepatomegaly, and collapsed right lower lobe, thus creating ashallower angle of the left mainstem bronchus from midline. The short incisor-to-carinadistance can be explained by ascites-induced cephalad shift of the mediastinum. (AnesthAnalg 2011;112:445–7)

There are no cases of unintentional left mainstem bronchial intubation during direct laryngoscopy inthe anesthesia literature. We herein report a case

with auscultatory, bronchoscopic, and radiographic evi-dence of inadvertent left mainstem bronchial intubation atan extremely short incisor-to-carina distance in a patientwith severe ascites.

CASE DESCRIPTION

A 59-year-old woman (157.5 cm, 85 kg, body mass index ϭ34.3 kg/m2) with a history of cryptogenic cirrhosis with

severe ascites, end-stage renal disease on hemodialysis,diabetes, and hypertension presented for debridement of bilateral lower extremity soft tissue infections. A preopera-tive chest radiograph, in the 45° sitting-up position, showeda new, markedly elevated right diaphragm to the sixth rib.With the patient’s head and neck in the sniffing position, arapid sequence induction was performed. A grade I laryn-goscopic view was obtained (100% of vocal cords seen) anda 7.0-mm internal diameter standard endotracheal tube(ETT) was passed in the normal orientation with theconcavity of the tube facing anteriorly, the Murphy eye atthe right lateral 3 o’clock position, and the bevel of the tubefacing to the left. The tube was secured with the 18-cm

mark on the tube at the right upper lateral incisor tooth.Breath sounds were heard over all the left lung fields butwere absent over all the right lung fields. The oxygensaturation ranged from 90% to 93% with peak inspiratorypressure of 35 cm H2O and arterial blood pressure and

heart rate stable within normal limits. An anteroposteriorchest radiograph was obtained while the fiberoptic bron-choscope was brought into the room. The bronchoscopewas passed through a bronchoscopy elbow adapter downthe ETT. From the tip of the ETT, 6 bronchial rings werecounted before a bifurcation, which was identified as thedivision of the bronchial airway into the left upper andlower divisions. Beyond this bifurcation, the left upperdivision bifurcated into the left upper lobe and lingula andthe lower division bifurcated into the superior segment (no.6) and the remainder of the segments (nos. 7–10) of the leftlower lobe. The ETT was pulled back and secured at 15 cm,

such that the tube was 1.5 cm above the carina, with equal bilateral breath sounds, oxygen saturation of 100%, andpeak inspiratory pressure 22 cm H2O. Subsequently, thechest radiograph (Fig. 1) demonstrated left mainstem bron-chial intubation, right lower lobe collapse, and markedlyelevated right hemidiaphragm to slightly above the sixthrib (basically the same as the preoperative chest radiographFig. 2), with a midline parasagittal angle of 31° between thetrachea and the left mainstem bronchus.

DISCUSSION

The above case is a unique example of a left mainstem bronchial intubation at an extremely short incisor-to-carina

distance in a 157.5-cm patient that was well proven with 3different diagnostic modalities. Left mainstem bronchialintubation is less common than right mainstem bronchialintubation, having been referenced only 3 times in themedical literature.1–3 One report1 mentioned that a leftmainstem bronchial intubation occurred in 1 patient withno other details. A second report2 provided radiologicproof that a left mainstem intubation occurred in 1 patientwith no other details. A third report3 provided auscultatorysupport and postmortem radiologic support in 1 patient fora left mainstem intubation. In the second and third re-ports,2,3 the intubations were performed by emergencyparamedical personnel during cardiopulmonary resuscita-

tion of the patients.

From the Department of Anesthesiology, University of California San Diego,San Diego, California.

Accepted for publication September 30, 2010.

The authors declare no conflicts of interest.

Address correspondence and reprint requests to Jonathan L. Benumof,MD, Department of Anesthesiology, UCSD Medical Center, 402 Dickin-son St., Suite 2-224, San Diego, CA 92103-8812. Address e-mail to

jbenumof @ucsd.ed u.

Copyright © 2011 International Anesthesia Research Society

DOI: 10.1213/ANE.0b013e31820472c0

February 2011 • Volume 112 • Number 2 www.anesthesia-analgesia.org 445



A standard ETT inserted in a normal manner will enterthe right mainstem bronchus for 3 reasons: first, the angle

of the right mainstem bronchus from the midline is moreshallow than the angle of the left mainstem bronchus fromthe midline (approximately 31° vs 49°); second, the orificeof the right mainstem bronchus has a greater surface areawith a more circular shape than the left mainstem bron-chus; third, and most importantly, the leftward-facing bevel of an ETT will deflect the ETT into the right mainstem bronchus when the bevel makes contact with the trachealcarina. Indeed, Kubota et al.4 and Baraka et al.5 were able toobtain a 92% and 100% incidence of left mainstem bronchialintubation, respectively, using ETTs with rightward-facing bevels. In our case, we hypothesize that the combination of the severe ascites and hepatomegaly pushed the right

hemidiaphragm more cephalad than the left hemidia-phragm, and along with the right lower lobe collapse,distorted the anatomy of the tracheal bifurcation, with theresultant angle of the left mainstem bronchus less than theangle of the right mainstem bronchus. Indeed, when a chestradiograph from before the patient developed ascites iscompared with the intraoperative chest radiograph, theangle of the left mainstem bronchus decreased from ap-

proximately 47° to 31°.In this case, the fiberoptic bronchoscopic, radio-

graphic, and auscultatory evidence confirm that the ETTwas already in the left mainstem bronchus at 18 cm (thedistance the ETT was secured at the right upper incisor)and that the incisor-to-carina distance was very close to16.6 cm; this is an extremely short distance given theaverage incisor-to-carina distance for a patient of 157.5cm is expected to be 24 cm.6 The fiberoptic evidence of 6 bronchial rings between the tip of the ETT and the bifurcation of the left mainstem bronchus into upper andlower divisions means that the ETT was into the leftmainstem by 2 bronchial rings. Given that the left

mainstem is uniform in length of 5 cm with 7 to 8 bronchial rings,7 our ETT was into the left mainstem by2 bronchial rings, or 1.4 cm; therefore, the carinal depthwas 18.0 Ϫ 1.4 ϭ 16.6 cm. The radiograph in theoperating room was entirely consistent with the conten-tion that the tip of the ETT was in the left mainstem by1.4 cm. The auscultatory findings were also consistentwith the fiberoptic bronchoscopic and radiographic find-ings. The distance between the distal margin of the cuff to the tip of the ETT is 1.4 cm; we believe the distalmargin of the cuff completely occluded the left mainstemorifice, thereby allowing left but not right lung ventila-tion. The extremely short 16.6-cm incisor-to-carina dis-tance is well explained by the patient’s severe ascitespushing the mediastinum cephalad, thereby shorteningthe incisor-to-carina distance. This situation (ascites in-duced migration of the mediastinum cephalad) is similarto right mainstem intubations during laparoscopy.8–10

Although it has been shown in the radiation oncologyliterature that the carina will change position slightlywith tidal breathing,11 we do not believe this to be themajor contributing factor in this case because the changesare often Ͻ5 mm in the craniocaudal direction, a distancethat cannot totally account for the extremely shortincisor-to-carina distance in this patient.

Right mainstem intubation is high on the differentialdiagnosis list when there are absent left lung breath

sounds; the differential also includes pneumo- or hemotho-rax, left mainstem occlusion by any type of extrinsic orintrinsic mass, massive left pleural effusion, and previousleft pneumonectomy. In patients with absent right-sided breath sounds, the differential rarely includes left main-stem intubation. Instead, pneumothorax, hemothorax, orrarely pleural effusions are considered, potentially leadingto inappropriate intervention. We propose that when onlyunilateral breath sounds are present and the ETT is at adepth Ͼ20 cm for patients Յ162.5 cm in height and, at adepth Ͼ22 cm for patients taller than 162.5 cm, the ETTshould be carefully and slowly withdrawn over severalventilations 2 to 3 cm while listening for restoration of

Figure 1. Preoperative chest radiograph, in the 45° sitting position,

showing markedly elevated right hemidiaphragm to the sixth rib.

Figure 2. Intraoperative chest radiograph showing markedly elevatedright hemidiaphragm to just above the sixth rib and the tip of the

endotracheal tube in the left mainstem bronchus.

CASE REPORT

446 www.anesthesia-analgesia.org ANESTHESIA & ANALGESIA



bilateral breath sounds. However, if bilateral breath soundsare not restored by these maneuvers, then the fiberoptic bronchoscope and chest radiograph should be obtained todetermine the cause of unilateral breath sounds.

This case also has implications for future research. Thehypothesis in this case was that the severe ascites, hepato-megaly, and right lower lobe collapse shortened the incisor-to-carina distance and changed the configuration of the

tracheal carina. To begin to evaluate this hypothesis, lapa-roscopic gas insufflation and the head-down position can be instituted in a graded manner both individually and incombination. Under these circumstances, the incisor-to-carina distance, the geometry, and the angles of the tracheal bifurcation could be measured with the results possiblyexplaining the left mainstem intubation at an extremelyshort distance, as in this case.

REFERENCES

1. Stauffer JL, Olson DE, Petty TL. Complications and conse-quences of endotracheal intubation and tracheostomy: a pro-spective study of 150 critically ill adult patients. Am J Med1981;70:65–76

2. Saunders CE, Sedman AJ. Left mainstem bronchus intubation.Am J Emerg Med 1984;2:406–7

3. Ribeiro BJ. Inadvertent intubation of the left mainstem bron-chus. Am J Med 1993;11:33–4

4. Kubota H, Kubota Y, Toyoda Y, Ishida H, Asada A, MatsuuraH. Selective blind endobronchial intubation in children andadults. Anesthesiology 1987;67:587–9

5. Baraka A, Akel S, Muallem M, Haroun S, Baroody M, SibaiAN, Louis F. Bronchial intubation in children: does the tube

bevel determine the side of intubation? Anesthesiology1987;67:869–70

6. Brodsky JB, Benumof JL, Ehrenwerth J, Ozaki GT. Depth of placement of left double-lumen endobronchial tubes. AnesthAnalg 1991;73:570–2

7. Benumof JL, Partridge BL, Salvatierra C, Keating J. Margin of safety in positioning modern double-lumen endotrachealtubes. Anesthesiology 1987;67:729–38

8. Chen PP, Chui PT. Endobronchial intubation during laparo-scopic cholecystectomy. Anaesth Intensive Care 1992;20:537–8

9. Burton A. Precipitous decrease in oxygen saturation duringlaparoscopic surgery. Anesth Analg 1993;76:1177–8

10. Mackenzie M, MacLeod K. Repeated inadvertent endobron-chial intubation during laparoscopy. Br J Anaesth2003;91:297–8

11. van der Weide L, van Sornsen de Koste JR, Lagerwaard FJ,Vincent A, van Triest B, Slotman BJ, Senan S. Analysis of carinaposition as surrogate marker for delivering phase-gated radio-

therapy. Int J Radiat Oncol Biol Phys 2008;71:1111–7

Left Main Intubation at a Short Distance

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