Mechanical injuries to the ipsilateral non-diseased lobes(s) during pulmonary resection--another factor causing postoperative complications

BACKGROUND

The occurrence of complications after major pulmonary resection is known to be related to various factors. However, peri-surgical injuries to the ipsilateral non-diseased lobes(s) occurring during resection have never been mentioned in the literature. This study aimed to verify the injury in cases after lobectomy and wedge resection.

METHODS

Data from eighteen patients who underwent lobectomy or wedge resection for malignant tumor between January 2003 and January 2004 were collected. All patients had pre- and postoperative examinations of alveolar-capillary membrane (A/C) permeability using 99m TC-DPTA radioaerosol.

RESULTS

Ten lobectomies and eight wedge resection were performed. Using the paired t-test with each patient's pre-operative A/C permeability as his own control data, the postoperative A/C permeability of the ipsilateral non-diseased lobe(s) was found to be significantly increased. The degree of increase in the lobectomy group was the same as that in the wedge resection group. However, no significant change was found on the contralateral side in both groups.

CONCLUSION

The degree of increase of permeability was the same in both groups, indicating that the effects of stretch on the surviving lung are not a contributing factor to the change in A/C permeability. The mechanical injuries during the pulmonary surgical procedure alter the permeability, which could be a possible factor causing postoperative pulmonary complications.

Using 99mTc-DTPA radioaerosol inhalation lung scan as compared with computed tomography to detect lung injury in blunt chest trauma

BACKGROUND

Detection of pulmonary contusion in patients with blunt chest trauma is very important so as to commence therapy immediately to avoid irreversible damage. The purpose of our study was to evaluate the efficacy of technetium-99m diethylene triamine pentaacetic acid (99mTc-DTPA) aerosol inhalation lung scintigraphy in comparison with chest computed tomography (CT) in the diagnosis of pulmonary contusion at acute blunt chest trauma.

METHODS

Twenty-nine patients with isolated blunt chest trauma were referred to the emergency department of our hospital, and nine healthy people participated in this study. Sixteen patients who had pulmonary contusion on CT scans were referred to as group 1, and 13 patients who had normal CT scans as group 2. Nine healthy people comprised a control group. 99mTc-DTPA aerosol inhalation lung scintigraphy was performed on the first day in all patients.

RESULTS

The mean half time (T1/2) and penetration index values of 99mTc-DTPA clearance were significantly lower in groups 1 and 2 compared with the control group. Among the three groups, there were no significant differences in arterial blood gas analysis except for PO2. The mean T1/2 value of 99mTc-DTPA clearance did correlate with PO2 values but not with pH, PCO2, or HCO3 values.

CONCLUSIONS

99mTc-DTPA radioaerosol inhalation lung imaging may serve as a useful adjunct and supportive method to chest CT scanning for detecting mild pulmonary contusion.

Evaluation of two-way protein fluxes across the alveolo-capillary membrane by scintigraphy in rats: effect of lung inflation

Pulmonary microvascular and alveolar epithelial permeability were evaluated in vivo by scintigraphic imaging during lung distension. A zone of alveolar flooding was made by instilling a solution containing99mTc-albumin in a bronchus. Alveolar epithelial permeability was estimated from the rate at which this tracer left the lungs. Microvascular permeability was simultaneously estimated measuring the accumulation of111In-transferrin in lungs. Four levels of lung distension (corresponding to 15, 20, 25, and 30 cmH2O end-inspiratory airway pressure) were studied during mechanical ventilation. Computed tomography scans showed that the zone of alveolar flooding underwent the same distension as the contralateral lung during inflation with gas. Increasing lung tissue stretch by ventilation at high airway pressure immediately increased microvascular, but also alveolar epithelial, permeability to proteins. The same end-inspiratory pressure threshold (between 20 and 25 cmH2O) was observed for epithelial and endothelial permeability changes, which corresponded to a tidal volume between 13.7 ± 4.69 and 22.2 ± 2.12 ml/kg body wt. Whereas protein flux from plasma to alveolar space (111In-transferrin lung-to-heart ratio slope) was constant over 120 min, the rate at which99mTc-albumin left air spaces decreased with time. This pattern can be explained by changes in alveolar permeability with time or by a compartment model including an intermediate interstitial space.