Pulmonary Function and Thoraco-abdominal Configuration After Elective Craniotomy:

Evaluation of lung volumes, vital capacity and respiratory muscle strength after cervical, thoracic and lumbar spinal surgery

CONTEXT AND OBJECTIVE

Studies have shown that physiopathological changes to the respiratory system can occur following thoracic and abdominal surgery. Laminectomy is considered to be a peripheral surgical procedure, but it is possible that thoracic spinal surgery exerts a greater influence on lung function. The aim of this study was to evaluate the pulmonary volumes and maximum respiratory pressures of patients undergoing cervical, thoracic or lumbar spinal surgery.

DESIGN AND SETTING

Prospective study in a tertiary-level university hospital.

METHODS

Sixty-three patients undergoing laminectomy due to diagnoses of tumors or herniated discs were evaluated. Vital capacity, tidal volume, minute ventilation and maximum respiratory pressures were evaluated preoperatively and on the first and second postoperative days. Possible associations between the respiratory variables and the duration of the operation, surgical diagnosis and smoking status were investigated.

RESULTS

Vital capacity and maximum inspiratory pressure presented reductions on the first postoperative day (20.9% and 91.6%, respectively) for thoracic surgery (P = 0.01), and maximum expiratory pressure showed reductions on the first postoperative day in cervical surgery patients (15.3%; P = 0.004). The incidence of pulmonary complications was 3.6%.

CONCLUSIONS

There were reductions in vital capacity and maximum respiratory pressures during the postoperative period in patients undergoing laminectomy. Surgery in the thoracic region was associated with greater reductions in vital capacity and maximum inspiratory pressure, compared with cervical and lumbar surgery. Thus, surgical manipulation of the thoracic region appears to have more influence on pulmonary function and respiratory muscle action.

Pulmonary function after surgery for congenital atlantoaxial dislocation: a comparison with surgery for compressive cervical myelopathy and craniotomy

Deterioration of pulmonary function after surgery for congenital atlantoaxial dislocation (AAD) has been documented in a few studies. We proposed that this deterioration in AAD is much higher than what can be expected after a surgical procedure under general anesthesia or what occurs after any surgery on the cervical spine. To test this hypothesis, we recorded forced vital capacity (FVC), forced expiratory ratio (FEV 1.0), forced expiratory flow (FEF 25%-75%) and muscle power in the extremities in 25 patients undergoing surgical correction of AAD (AAD group), 29 patients undergoing surgery for compressive cervical spine lesions (cervical spine group) and 20 patients undergoing craniotomy for an intracranial lesion (craniotomy group). The observations were made before surgery and on postoperative days 1 and 7. The demographic characters were comparable among the 3 groups. All patients underwent an uneventful surgery and their trachea was extubated in the operating room. There was no decrease in the muscle power in the postoperative period in any of the groups. A significant decrease in FVC (expressed as percentage of the predicted value) was seen postoperatively in all the 3 groups. The reduction of FVC was significantly different among the groups, with the AAD group having the lowest values (P<0.001). The FVC values in the AAD group were 74.6+/-19.6%, 49.6+/-17.7%, 64.0+/-20.8% at baseline, on postoperative days 1 and 7, respectively (P<0.001). Postoperative change in forced expiratory ratio was also significantly different among the groups (P=0.03). A significant difference was found between the AAD and cervical spine group (89.8+/-8.3%, 88.2+/-17.6%, 89.3+/-9.8% in the AAD group and 95.5+/-20.5%, 78.4+/-13.4%, 72.7+/-19.1% in the cervical spine group at baseline and on postoperative days 1 and 7, respectively, P<0.05). FEF 25%-75% changes were also significantly different among the groups (P<0.001). The decrease in the AAD and cervical spine groups was significantly higher than that in the craniotomy group (P<0.001). In conclusion, during the first week after surgery, deterioration of pulmonary function in the AAD group is significantly different from that seen in patients undergoing surgery for compressive cervical lesions or craniotomy for a cerebral lesion. The data imply the need for special attention to respiratory function in patients operated for AAD in the postoperative period.