Anesthesia for thoracoscopic laser ablation of bullae in a patient with severe bullous emphysema
Saito, Y.; Hayashida, M.; Arita, H.; Hanaoka, K.
Masui. Japanese Journal of Anesthesiology 44(5): 704-709
1995
ISSN/ISBN: 0021-4892 PMID: 7609300 Document Number: 452083
A 46-year-old male underwent laser-ablation of emphysematous bullae of the right lung via thoracoscope. For almost a year he had been bedridden because of severe dyspnea on exertion, in spite of medication and oxygen therapy. He also complained of orthopnea at rest and had suffered from body weight loss of 10 kg during the preceding year. Radiologic examination revealed emphysematous lung with bilateral giant bullae. In spirogram, forced vital capacity in 1 second was markedly low (0.45 l, corresponding to 19% in %FVC-1.0), vital capacity moderately depressed (2.41 l, 64%) and residual volume markedly elevated (5.85 l, 387%). Anesthesia was induced and maintained using the combination of thoracic-epidural anesthesia and intravenous anesthesia (midazolam and fentanyl). One lung ventilation (OLV) was used to facilitate thoracoscopic procedure. Mechanical ventilation was conducted at first with an anesthesia ventilator. As the duration of OLV was prolonged, however, the peak airway pressure increased, the tidal volume decreased and the value of percutaneous arterial hemoglobin saturation (Sp-O-2) declined. In order to keep adequate oxygenation, brief periods of two lung ventilation (TLV) became necessary, in addition to the application of continuous positive airway pressure to the non-dependent lung. When ventilation was changed from volume-cycled ventilation to pressure-cycled and from using an anesthesia ventilator to a critical care type ventilator (Servo 900C), sufficient tidal volume was achieved with lower peak airway pressure, producing reasonable Sp-O-2 value with much less frequent TLV. At the end of the surgery bronchopleural fistulae still persisted, with resultant air leak of about 50% of inspired tidal volume. For this reason the patient required assisted ventilation postoperatively for a prolonged period of time. On the 10th postoperative day, the patient was successfully weaned from the ventilator. After weaning FEV-1.0 increased only minimally to 0.61 l (26% in %FEV-1.0), but residual volume decreased markedly to 3.56 l (236%). The patient showed dramatic improvement of symptoms. He left hospital on foot. A critical care type ventilator, Servo 900C, was required, not only because of large bronchopleural fistulae associated with laser ablation, but also because of flow limitation of the usual anesthesia ventilator in the presence of high airway resistance. This ventilator was equipped with pressure-cycled ventilation mode and was capable of delivering high gas flow even in the presence of high airway pressure.