Effects of steep Trendelenburg position for robotic-assisted prostatectomies on intra- and extrathoracic airways in patients with or without chronic obstructive pulmonary disease

The use of the steep Trendelenburg position and abdominal CO2-insufflation during surgery can lead to significant reduction in pulmonary compliance and upper airway oedema. The postoperative time course of these effects and their influence on postoperative lung function is unknown. Therefore, we assessed intra- and extrathoracic airway resistance and nasal air flow in patients with or without chronic obstructive pulmonary disease (COPD) during robotic-assisted prostatectomy. In 55 patients without and 20 patients with COPD spirometric measurements and nasal resistance were obtained before operation, 40 and 120 min, and 1 and 5 days after operation. We measured vital capacity (VC), forced expiratory volume in 1 s (FEV1), maximal mid-expiratory and inspiratory flow (MEF50, MIF50), arterial oxygen saturation, and nasal flow. The occurrence of postoperative conjunctival oedema (chemosis) was also assessed. In patients without COPD, MEF50/MIF50 increased and nasal flow decreased significantly after surgery (P < 0.0001) and normalized within 24 h. VC and FEV1 decreased after operation with a nadir at 24 h and recovered to normal until the fifth day (P < 0.0001). In patients with COPD, changes in MEF50/MIF50 and nasal flow were similar, while changes in VC and FEV1 lasted beyond the fifth day (P < 0.0001). Robotic-assisted prostatectomy in the steep Trendelenburg position led to an increase in upper airway resistance directly after surgery that normalized within 24 h. The development of chemosis can be indicative of increased upper airway resistance. In patients without COPD, VC and FEV1 were reduced after surgery and recovered within 5 days, while in patients with COPD, the alteration lasted beyond 5 days.