VENTILATION during lung isolation for thoracic surgery is complicated by decreased pulmonary compliance and increased venous admixture (shunt). Compared with two-lung ventilation, a higher inspired airway pressure is required to create an equivalent tidal volume, and there is a greater potential for significant hypoxemia. These problems are exaggerated when ventilation is attempted via a lung that has previously undergone a large resection, such as complete or partial lobectomy.
We report a novel combination of a double lumen tube (DLT) and bronchial blocker to provide suitable conditions for right upper lobe surgery in a patient who had recently undergone a left upper lobectomy.
Case Report
A 63-year-old man was diagnosed with two concurrent primary lung tumors, one in the left upper lobe, the other in the right upper lobe. The patient was obese (body mass index, 36 kg m−2) but had no other significant comorbidities. For surgical indications, it was decided to resect the left upper lobe tumor first. The patient underwent an uneventful left upper lobectomy using a 39 F left DLT (Broncho-Cath, Mallinckrodt Inc., St. Louis, MO) for intraoperative lung isolation.
Six weeks later, the patient was rescheduled for resection of the right upper lobe tumor. An epidural catheter was placed preoperatively. Arterial blood gases while the patient was breathing room air showed a pH 7.44, pCO239 mmHg, and pO288 mmHg. After intravenous induction, an Arndt Endobronchial Blocker (Cook Inc., Bloomington, IN) was inserted and advanced through the vocal cords. The patient was then intubated with a 37 F left DLT (Bronch-Cath) placed next to the blocker. A smaller DLT was chosen on this occasion so that the airway could accommodate the two devices. A fiberoptic bronchoscope was inserted via the tracheal lumen of the DLT, and the bronchial cuff was positioned in the left main bronchus just beyond the carina. The blocker was then advanced under vision into the bronchus intermedius of the right main bronchus so that its balloon came to lie beyond the orifice of the right upper lobe bronchus (fig. 1). General anesthesia was maintained by sevoflurane in oxygen.
Fig. 1. The left-sided double lumen tube positioned in the left main bronchus (previous upper lobectomy). The endobronchial blocker positioned in the bronchus intermedius of the right lung.
Fig. 1. The left-sided double lumen tube positioned in the left main bronchus (previous upper lobectomy). The endobronchial blocker positioned in the bronchus intermedius of the right lung.
The patient was turned onto the lateral position and the surgery began. When the surgeon requested collapse of the right lung, the balloon of the blocker was inflated and the tracheal lumen of the DLT opened to the atmosphere. The right upper lobe was thus isolated from the left lung by the bronchial cuff of the DLT, and from the middle and lower lobes of the right lung by the blocker balloon. Continuous positive airway pressure (CPAP), 2 cm H2O with 100% oxygen, was then applied to the right middle and lower lobes via the bronchial blocker. This arrangement allowed for unimpeded collapse of the right upper lobe and for surgery to proceed unhindered by movement within the right chest. Pressure-controlled mode was used for ventilation of the dependent lung at a rate of 14 and pressure of 28 cm H2O, producing tidal volumes of 400 to 450 mL. Arterial blood gas analysis 15 min after this maneuver showed pH 7.37, pCO250 mmHg, and pO2146 mmHg. A peripheral tumor was found in the right upper lobe and was removed by wedge resection. The arterial oxygen saturation remained at 99% throughout.
Previously undiagnosed tumors were then discovered in the right middle lobe. The surgeons requested the CPAP to be removed for their assessment and subsequent excision by wedge resections. Arterial blood gases performed 15 min after CPAP removal and collapse of the right middle and lower lobes showed a pO2of 104 mmHg and Sao2of 97%.
The procedure took 150 min and was uneventful. At completion, the trachea was extubated and the patient made an otherwise routine recovery.
Discussion
We describe the combined use of DLT and bronchial blocker to electively secure selective lobar isolation. This differs from previously reported DLT–bronchial blocker combinations in which the role of the blocker has been to rescue an unexpected malposition of the DLT. 1–3Our combination produced a unique situation for thoracic surgery. Oxygenation was provided via both the remaining ventilated left lower lobe and the CPAP applied to the isolated right middle and lower lobes. Carbon dioxide clearance was achieved via the ventilated left lower lobe. The right upper lobe collapsed freely and the remaining right lung remained quiescent and isolated. Peak airway pressure in the left lung was maintained at less than 30 cm H2O, and a minor degree of hypoventilation and respiratory acidosis were accepted.
According to a model for calculating the proportion of functional lung tissue remaining postresection, 4our patient could be predicted to have lost 24% of lung function following his initial left upper lobectomy. A subsequent right thoracotomy with conventional lung isolation via a left DLT would require intraoperative gas exchange via 30% of the total remaining segmental lung function. In our opinion, it was unpredictable as to whether the patient would be able to tolerate this approach without risking hypoxemia, barotrauma, or pulmonary overdistention. 5Hypoxemia during one lung ventilation can usually be successfully managed by applying CPAP with oxygen to the operative lung, but this provides less than optimal operating conditions. In retrospect, we acknowledge that this patient might have tolerated the entire procedure by conventional lung isolation, as demonstrated by his ability to maintain arterial oxygen saturation after the blocker was deflated and selective lobar CPAP was removed.
Selective lobar collapse, using the combination of a single lumen tube and bronchial blocker, has been described in the context of previous contralateral pulmonary resection. 6,7Campos, using a single lumen tube and open channel blocker, was able to show improved oxygenation when CPAP with oxygen was applied during selective lobar isolation. 8However, the use of a single lumen tube dictates selective blockade of the operative lobe. Ventilation and lung movement continue within the surgical hemithorax, and the use of selective CPAP to the operative lobe might not be appreciated by the surgeon. Our combination of DLT with a bronchial blocker placed in the anatomically aligned bronchus intermedius provided both flexibility and stability. The motionless right chest with fully collapsed right upper lobe offered the surgeon optimal operating conditions.
With the implementation of surveillance protocols following pulmonary resection for lung cancer, we might expect a greater detection rate for patients developing a second resectable primary lung tumor. 9It is also now not uncommon for patients to present for repeat thoracotomies for resection of certain types of metastatic tumors within the lungs. Therefore, in the future, it is likely that the number of patients presenting for a subsequent, often contralateral, pulmonary resection will increase. Anesthetists managing these complex thoracic cases must be able to use the full range of airway devices available, and in a manner that involves adaptation to the individual anatomic variations presented by each situation.
