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On-line version ISSN 1806-907X
Rev. Bras. Anestesiol. vol.56 no.1 Campinas Jan./Feb. 2006
Complication related to tracheal bronchus in infant. Case report*
Complicación debida a la presencia de bronquiotraqueal en un lactante. Relato de caso
Jaqueline Costa ReisI; César Romão Martins, TSAII; Luiz Hirotoshi OttaIII; Maria Angela Tardelli, TSAIV; José Luiz Gomes do Amaral, TSAV
IAnestesiologista do Hospital São
Paulo, UNIFESP, EPM
IIAnestesiologista, Preceptor dos Residentes do CET da UNIFESP, EPM
IIIMédico Pneumologista, Chefe do Setor de Broncoscopia da UNIFESP, EPM
IVProfessora Adjunta da Disciplina de Anestesiologia, Dor e Terapia Intensiva da UNIFESP, EPM
VProfessor Titular da Disciplina de Anestesiologia, Dor e Terapia Intensiva da UNIFESP, EPM
BACKGROUND AND OBJECTIVES:
Tracheal bronchus is a congenital abnormality affecting approximately 2% of
general population, usually asymptomatic and of incidental diagnosis. It is
characterized by the presence of the bronchus to the right upper lobe emerging
directly from the trachea, close to the carina. Tracheal tube may obliterate
its lumen, leading to right upper lobe atelectasis. This article aimed at reporting
a case of right upper lobe atelectasis in infant, noticed after tracheal intubation,
and also presenting a literature review on this abnormality, highlighting its
CASE REPORT: Male patient, mulatto, 5 months old, 5 kg, physical status ASA I, scheduled for anorectal fistula correction (Mini-Peña). Right subclavian vein was punctured after tracheal intubation, followed by desaturation and decreased right apex vesical murmur. Initial hypotheses were hemothorax, pneumothorax, bronchial secretion and selective intubation. Chest X-rays have shown right upper lobe atelectasis. Bronchoscopy revealed tracheal bronchus. Tube was repositioned with re-expansion of the affected lobe.
CONCLUSIONS: Because of its relatively high incidence (2%), tracheal bronchus should be included among right upper lobe atelectasis differential diagnoses.
Key Words: ANESTHESIA, Pediatric; COMPLICATIONS: tracheal bronchus
JUSTIFICATIVA Y OBJETIVOS:
El bronquio traqueal es una anomalía congénita con incidencia de aproximadamente
2% en la población y cuyo diagnóstico habitual es incidental. Se caracteriza
por la emergencia del bronquio para el lóbulo superior derecho directamente
desde la traquea, próximo a la carina. Al proceder a la intubación
traqueal su luz puede ser ocluida por la sonda y ser causa de atelectasia exclusiva
del lóbulo superior derecho. El objetivo de este artículo es relatar
un caso de atelectasia del lóbulo superior derecho en un lactante, solo
percibida después de la intubación traqueal y hacer una revisión
de la literatura sobre este tópico destacando su importancia para la anestesia.
RELATO DEL CASO: Paciente masculino, pardo, 5 meses de edad y 5 kg de peso, estado físico ASA I, portador de fístula ano-rectal, programado para corrección de la fístula con la técnica de mini-Peña. Luego de la intubación traqueal se realizó punción de la vena subclavia derecha, ocurriendo caída de la saturación de O2 y disminución de ventilación en el ápice derecho. Inicialmente las hipótesis fueron hemotórax, neumotórax, secreción bronquial excesiva o intubación selectiva. Fue realizada radiografía de tórax que mostró atelectasia exclusiva del lóbulo superior derecho. La broncoscopía reveló la presencia de bronquio traqueal. La sonda traqueal fue reposicionada y el lóbulo derecho se re-expandió.
CONCLUSIONES: Como se trata de una anomalía con incidencia relativamente alta (2% de la población), el bronquio traqueal debe ser incluido entre los diagnósticos diferenciales en atelectasia del lóbulo superior derecho.
Tracheobronchial tree abnormalities are in general asymptomatic in non-anesthetized patients. These abnormalities are evidenced after tracheal intubation when the abnormal bronchus lumen can be blocked by the tube. This report aimed at describing the case of an asymptomatic child who developed right upper lobe atelectasis after tracheal intubation related to the presence of a tracheobronchial tree abnormality called tracheal bronchus, as well as presenting a literature review on this clinical entity and its anesthetic implications.
A 5 months old male mulatto patient, 5 kg, born at term (38 weeks), physical status ASA I and normal neuropsychomotor development, was referred to the Surgical Center for anorectal fistula correction. At physical evaluation, patient was conscious, relaxed and with normal cardiopulmonary auscultation.
The infant was brought from the ward with a 24G venous access on left arm and no premedication.
Monitoring consisted of pulse oximetry (SatO2), cardioscope (HR) and noninvasive blood pressure (NIBP). Baseline parameters were BP = 110 x 80 mmHg, SatO2 = 98% and HR = 120 bpm. Anesthesia was started with 100% oxygen for 5 minutes and intravenous alfentanil (0.2 mg), propofol (20 mg) and vecuronium (0.5 mg). Tracheal intubation was performed with a 4.0 cuffless tube which allowed some leakage during ventilation in Res-Baraka system (Mapleson D). It was so replaced by a 4.5 cuffless tube, and intubation confirmed by capnography (PETCO2 = 30 mmHg) and bilateral pulmonary auscultation. Patient was maintained under pressure-controlled ventilation with 1:1 oxygen/nitrous oxide and sevoflurane. Parameters after induction were: HR = 100 bpm, SatO2 = 98%, NIBP = 100 x 70 mmHg.
Because of the postoperative parenteral nutrition indication, the right subclavian vein was punctured for double-lumen catheter insertion. After catheter installation, there was decreased saturation to 93% and PETCO2 to 20 mmHg, with decreased right apex vesical murmurs. The initial hypotheses were pneumothorax, tracheal secretion, selective intubation and/or hemothorax. X-rays (Figure 1) have evidenced right upper lobe atelectasis, double lumen catheter coiled around right subclavian vein and distal tracheal tube tip close to the carina. The tracheal tube and central catheter were then both pulled backwards a little. Control X-rays (Figure 2) have shown persistence of right upper lobe atelectasis and adequate central catheter and tracheal tube positioning.
Surgery was interrupted and diagnostic bronchoscopy was requested (Figure 3). Diagnosis was tracheal bronchus (congenital abnormality), where the right upper lobe bronchus emerged from the tracheal wall, close to the carina, resulting in its obliteration by the tracheal tube. The tube was then repositioned assisted by fibroscopy, followed by re-expansion of atelectasis and improved pulmonary auscultation. There was no tracheal secretion.
Post-bronchoscopy parameters were SatO2 = 99% and PETCO2 = 36 mmHg. Neuromuscular block reversal was not needed and extubation occurred normally. Diagnosis and treatment of right upper lobe atelectasis took approximately 3 hours and surgery was postponed. Patient was referred to the post-anesthetic recovery unit and was maintained under oxygen mist (5 L.min-1) with SatO2 = 97 %, BP = 110 x 75 mmHg and HR = 110 bpm.
One week later, patient was once again referred to the Surgical Center and was submitted to the proposed procedure uneventfully, respecting the anatomic parameters of the congenital abnormality.
Tracheal bronchus is defined as an aberrant bronchus most frequently emerging from the right tracheal wall above the carina, as result of abnormal development during early embryonal period1.
Its incidence varies according to the diagnostic method. Bremer2, in a pathological study from 1932, diagnosed the abnormality in 4 out of 80 fetuses resulting from spontaneous abortions (5%). Inada & Kashimoto3, in 1957, reported incidence of 0.1% to 0.6% after Japanese literature review. Le Roux4, in 1962, observed the abnormality in 30 out of 1000 consecutive bronchographies (3%). OSullivan et al.5, in 1998, reported 2% incidence in a literature review including several diagnostic methods such as CT and bronchoscopy. It is accepted that the overall incidence is approximately 2% and that the higher number reported by Bremer is a result of his method, since it is well known that congenital abnormalities are present in higher incidence in fetuses resulting from spontaneous abortions.
Regarding the etiology, Alescio et al.6 have proven that tracheal bronchus formation is an embryogenesis defect rather than a genetic abnormality. The study has shown that bronchial mesenchyma transplantation in the tracheal epithelium has resulted in tracheal bronchus.
Tracheal bronchi may present with different anatomic patterns. Figure 4 shows right tracheal bronchus patterns2. There are also reports on right upper lobe bronchus emerging from the left main bronchus7.
This condition is usually asymptomatic, but may be followed by lobe pneumonias or right upper lobe repetition atelectasis8,9.
Diagnosis is often incidental and achieved by bronchography, bronchoscopy or chest CT8,9.
It is commonly not associated to other congenital anomalies; however there are reports10 of associated tracheal hypoplasia, tracheal stenosis, lobe emphysema, cystic pulmonary lesions, cardiovascular disorders, other bronchial tree disorders and Down syndrome. The presence of hypoplasia, or fusion of first and second costal arches, bilateral lumbar ribs and other vertebral abnormalities increases the suspicion of tracheal bronchus or tracheo-esophageal fistula. Left abnormalities may be associated to brain anomalies.
Tracheal bronchus is also known as swines bronchus since swine have natural tracheal bronchus.
The tracheal tube can obliterate the tracheal bronchus lumen, leading to atelectasis of the involved lobe. Diagnosis of this collapsed area in children is difficult because the short distance between atelectasis areas and normally ventilated areas may mislead auscultation, as in this case. In the beginning, auscultation was apparently normal, probably due to transmission of sounds from adjacent areas.
High blood pressure values for the age were probably caused by the choice of inadequately short cuff, which overestimates real blood pressure value. As we couldnt replace it at that time, we decided to follow blood pressure by its temporal evolution.
This case reinforces the attention to be given by anesthesiologists to this abnormality of relatively high incidence, warning for the possibility of bronchial obliteration to the right upper lobe after tracheal intubation, especially in pediatric patients.
Because its relatively high incidence (2%), tracheal bronchus should be included among right upper lob atelectasis differential diagnoses.
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03. Inada K, Kashimoto S - An anomalous tracheal bronchus to the right upper lobe. Dis Chest, 1957;140:671-674. [ Links ]
04. le Roux BT - Anatomical abnormalities of the right upper bronchus. J Thorac Cardiovasc Surg, 1962;44:225-227. [ Links ]
05. OSullivan BP, Frassica JJ, Rayder SM - Tracheal bronchus: a cause of prolonged atelectasis in intubated children. Chest, 1998;113:537-540. [ Links ]
06. Alescio T, Cassini A - Introduction in vitro of tracheal buds by pulmonary mesenchyme grafted on tracheal epithelium. J Exp Zool, 1962;150:83-94. [ Links ]
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10. Weigel W, Kaufmann HJ - The frequency and types of other congenital anomalies in association with tracheoesophagel malformations. Radiologic study of 83 such infants. Clin Pediatr, 1976;15:819-834. [ Links ]
Dra. Maria Angela Tardelli
Address: Rua Napoleão de Barros, 715, 4º Andar
ZIP: 04024-002 City: São Paulo, Brazil
Submitted for publication April 13, 2005
Accepted for publication December 14, 2005
* Received from Universidade Federal de São Paulo, Escola Paulista de Medicina (UNIFESP, EPM), São Paulo, SP