Reliable noninvasive parameters for early detection of cardiopulmonary compromise induced by carbon dioxide thoracoretroperitoneum in minimally invasive thoracolumboendoscopic spine surgeryrid=""id=""Presented at the annual meeting of the Society of American Gastrointestinal Endoscopic Surgeons (SAGES), San Antonio, Texas, USA, 24–27 March, 1999

Abstract

Background: Using a novel endoscopic retroperitoneal approach for thoracolumbar anterior spine fusion, we examined the cardiopulmonary effects of the inevitably associated carbon dioxide (CO₂) thoracoretroperitoneum and evaluated noninvasive parameters, which may provide early and adequate recognition of cardiopulmonary dysfunction.

Methods: Under balanced anesthesia and paralysis, six pigs subjected to endoscopic CO₂ thoracoretroperitoneal spine fusion underwent extensive pulmonary and hemodynamic online monitoring throughout the operative procedure. Open thoracophrenolumbotomy in six pigs served as a control procedure.

Results: In contrast to unchanged cardiopulmonary parameters during open thoracolumbar spine surgery, CO₂ thoracoretroperitoneum caused significant hypercapnia, hypoxia, and acidemia with concomitant tachycardia, pulmonary hypertension, and systemic hypotension. Ventilatory adjustment, CO₂ evacuation, or both promptly reversed the cardiopulmonary effects. Noninvasively assessed end-tidal CO₂, peak respiratory pressure, and heart rate were early clues for detecting the tension pneumothorax-like cardiopulmonary dysfunction, as indicated by a significant correlation with the invasively assessed pulmonary hemodynamic parameters and arterial blood gases.

Conclusions: During endoscopic thoracolumbar spine fusion, CO₂ thoracoretroperitoneum induces cardiopulmonary dysfunction, which, however, can be detected reliably by changes in end-tidal CO₂, peak respiratory pressure, and heart rate, and which can be corrected immediately by appropriate ventilatory adjustments. Therefore, endoscopic CO₂ thoracoretroperitoneal spine fusion might not necessarily require extraordinarily extensive and invasive monitoring of systemic and pulmonary hemodynamics, but ventilatory adjustment and intrathoracic pressure evacuation should be readily available to reexpand the lung, and to facilitate rapid normalization of hemodynamic conditions.