OBJECTIVESTo evaluate the incidence of immediate postoperative pulmonary complications and their correlation to preoperative pulmonary function tests (PFTs), preoperative pulmonary symptoms and surgical approaches.

METHODSThe case records of 298 patients, who underwent anterior or posterior fusion, were reviewed. Preoperative PFTs were recorded and abnormal PFTs were defined as forced vital capacity (FVC) is less than 80% of FVC predicted. Preoperative pulmonary symptoms (breathless on exertion) were noted, and postoperative pulmonary complications were defined when the presence of atelectasis, infiltrates, pneumothorax, hemothorax, pneumonia or requirement of postoperative ventilatory support was noted.

RESULTSThe mean age of this group was 16.4 years (range from 6-62 years). The average coronal Cobb angle was 73.26 degrees (range from 45 degrees-141 degrees ). Of all the patients, 115 patients had normal preoperative PFTs, the other 183 cases had abnormal PFTs. Nineteen cases of all the patients were found with postoperative pulmonary complications including postoperative ventilatory support in 6 cases, atelectasis in 4 cases, infiltration in 2 cases, pneumothorax in 3 cases, pneumonia in 3 cases and hypoxemia in 1 case. The incidence of postoperative pulmonary complication was 6.4% in all the patients, while 18.99% in the 79 patients with thoracotomy and 1.85% in the 216 patients without. The correlation between postoperative pulmonary complications and the surgical approach was statistically significant (P=0.0000). When the patients were classified into 3 groups: 60%< FVCR <80%, 40%< FVCR <60%, FVCR <40%, the incidence of postoperative pulmonary complications were 2.72% (3/110), 7.40% (4/54) and 31.6% (6/19) respectively, which showed an increasing complication incidence. In the 115 patients with normal PFTs, 3 patients had preoperative pulmonary symptoms (2.68%), while 14 of the 183 patients with abnormal PFTs had preoperative pulmonary symptoms (7.65%). The correlation between presence of preoperative respiratory symptoms and abnormal results on PFTs was statistically significant (P=0.01). No significant correlation was found between preoperative respiratory symptoms and postoperative pulmonary complications (P=0.52).

CONCLUSIONSThe incidence of postoperative pulmonary complications increases with the deterioration of PFTs. The posterior procedure has a very low incidence of postoperative pulmonary possibility of complications, but a transthoracic procedure increases the complications significantly. Preoperative respiratory symptoms usually predict abnormal results of PFTs but have no correlation with postoperative pulmonary complication.