Noninvasive positive pressure ventilation prevents postoperative pulmonary complications in chronic ventilators users

To evaluate the postoperative pulmonary complications and the long-term impact on pulmonary function of different surgical procedures with general anaesthesia in chronic respiratory failure (CRF) patients who were using noninvasive positive pressure ventilation (NPPV).

We retrospectively studied 20 stable patients on NPPV for CRF secondary to: kyphoscoliosis (eight), morbid obesity (six), thoracoplasty (four), neuromuscular diseases (two), who underwent surgical procedures with general anaesthesia, between January 1998 and December 2003.

The variables studied were: type of surgery, hours of orotracheal intubation, hours of stay in the postsurgical reanimation unit (PRU), postoperative pulmonary complications and days of hospital stay. These results were compared with those obtained in patients without respiratory pathology and who were submitted to the same type of surgical interventions during the study period. All patients were tested for: arterial blood gases, forced vital capacity (FVC) and forced expiratory volume in 1s (FVE1). These tests were carried out both prior to surgical intervention and 12 months after this intervention, and the use of medical assistance resources the year prior to and the year after the surgical intervention were also analysed.

Sixteen patients were using NPPV at home at the time of the intervention and four patients were adapted to NPPV before surgery. The surgical procedures were: gastroplasty: six; mastectomy: five; septoplasty: three; hip prosthesis: two; cholecystectomy: one; Gasserian ganglion thermocoagulation: one; hysterectomy: one; and endoscopic retrograde cholangiopancreatography (ERCP): one. The mean postoperative intubation time was 3.8+/-3.2h, and only one patient remained intubated for more than 12h. The mean stay in the PRU was 19+/-9h (vs 19+/-6h in the general population, p>0.05). The days of hospital stay for the different pathologies were in the majority of cases greater than in the general population. We did not find significant differences on comparing the arterial blood gases, in pulmonary function or in use of assistance resources between the year previous to and the year following the surgical intervention.

In high-risk patients with chronic respiratory failure as a consequence of a restrictive lung pathology, NPPV can play an important role to confront surgical procedure with general anaesthesia with greater security. To obtain these results, it was fundamental to coordinate between the Pulmonary Services and the Anaesthesia Services as well as to follow up jointly in the PRU.