title: Reliable noninvasive parameters for early detection of cardiopulmonary compromise induced by carbon dioxide thoracoretroperitoneum in minimally invasive thoracolumboendoscopic spine surgery.
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.
authors.affiliation: Institute for Clinical and Experimental Surgery, University of Saarland, Homburg/Saar, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Vollmar
authors.forename: A
authors.initials: A
authors.lastname: Olinger
authors.forename: U
authors.initials: U
authors.lastname: Hildebrandt
authors.forename: M D
authors.initials: MD
authors.lastname: Menger
mesh_terms: D000818:Animals; D002245:Carbon Dioxide; D005260:Female; D006439:Hemodynamics; D006935:Hypercapnia / Q000175:diagnosis / Q000209:etiology; D016857:Hypocapnia / Q000175:diagnosis / Q000209:etiology; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D011028:Pneumoperitoneum, Artificial; D015656:Respiratory Mechanics; D013123:Spinal Fusion / Q000379:methods*; D013552:Swine; D013904:Thoracic Vertebrae / Q000601:surgery; D013990:Tidal Volume
chemical_list: D002245:Carbon Dioxide