One lung ventilation in a patient with an upper and lower airway abnormality
A 17-year-old girl with severe kyphoscoliosis presented with breathlessness and productive cough of one week duration. She was referred to our institute as a case of non-resolving left pneumothorax. Significant history included open heart surgery for ventricular septal defect closure at 4 years of age and spinal instrumentation for correction of kyphoscoliosis at the age of 15 years. On examination, she was emaciated, weighing 35 kg, and had severe thoracic kyphoscoliosis and generalized muscle wasting. Airway evaluation revealed limited mouth opening with inter-incisor distance of 1 cm, Mallampati Score was IV, and Atlanto-occipital joint extension was grade IV (<12). Respiratory system examination revealed a decreased air entry on the left chest. Chest radiography and computed tomography displayed a large pneumothorax with complete atelectasis of the left lung and airway distortion with deviated trachea and bilaterally narrowed bronchi []. Transthoracic echocardiography showed good biventricular function with no evidence of pulmonary hypertension.\nDespite conservative management for two weeks, which involved insertion of intercostal drains, there was no improvement in the left lung status. The possible aetiology for the non-resolving left pneumothorax was multiple bullae in a hypoplastic lung. The hypoplasia of the left lung was probably due to the spinal deformity that the patient had. Due to the non-resolving nature of the left pneumothorax, an informed consent was obtained and the patient was taken up for a pleurectomy.\nIn view of anticipated difficult airway access, an awake fiberoptic tracheal intubation was planned. After premedication with oral midazolam, under standard American Society of Anaesthesia (ASA) monitoring guidelines, the right radial artery was cannulated under topical anesthesia for invasive arterial pressure monitoring. Despite topicalization of the upper airways with local anesthetic, the patient remained uncooperative for any kind of airway instrumentation. After further sedation with intravenous fentanyl (50 μg) and midazolam (1 mg), general anesthesia was induced with titrated concentrations of sevoflurane taking care to maintain spontaneous breathing. A lubricated nasopharyngeal airway was inserted in the left nostril to administer oxygen and sevoflurane. A 7.0-size cuffed endotracheal tube was successfully introduced into the patient's trachea through the right nostril under the guidance of a 4.0-mm diameter fiberoptic scope (LF-1 Olympus).\nOnce airway control was achieved, a muscle relaxant (cis-atracurium) was administered. In view of distorted trachea & bronchi it was decided to use an endobronchial blocker for achieving OLV as was the request from the surgical side. Using the special multiport adaptor provided, a five-size Arndt wire-guided endobronchial blocker (Cook, Inc., Bloomington, IN) was introduced coaxially through the nasotracheal tube. Under fiberoptic guidance, the blocker was placed in the left main bronchus. A left thoracotomy was performed. Standard lung-deflation technique was used and OLV was instituted. The surgical procedure proceeded uneventfully with good visualization of the operative field. Pressure control ventilation with positive end expiratory pressure (4 cm H2O) and peak airway pressures up to 24 cm H2O were used throughout the surgery. Inspired oxygen concentration (FiO2) and the respiratory rate were adjusted based on serial arterial blood gas analysis, pulse oximetry (SpO2) and end tidal carbon dioxide concentration (EtCO2) values during both lung ventilation and OLV. The patient remained haemodynamically stable with adequate oxygenation and ventilation. After completion of surgery, the blocker balloon was deflated and the left lung was expanded. The blocker was then removed with the nasotracheal tube left in situ.\nIn view of the chest deformities and difficulties with airway access, the patient was gradually weaned off artificial ventilation after four hours of elective mechanical ventilation in the post-cardiothoracic surgery intensive care unit. Postoperative analgesia was provided with fentanyl infusion and the patient's trachea was extubated successfully with satisfactory arterial blood gases. Serial chest radiographs showed good left lung expansion and, after an uneventful postoperative course, the patient was discharged home on seventh postoperative day.