ABSTRACT
Objective:To evaluate the protective effect of pressure-controlled volume-guaranteed ventilation (PC-VG) combined with dexmedetomidine on the lung of pediatric patients undergoing laparoscopic surgery.Methods:Forty-eight pediatric patients of either sex, aged 2-6 yr, weighing 8-21 kg, scheduled for elective laparoscopic pyeloplasty, were divided into 3 groups ( n=16 each) using a random number table method: volume-controlled ventilation (VCV) group (V group), PC-VG group (P group), and PC-VG combined with dexmedetomidine group (PD group). In PD group, dexmedetomidine was intravenously infused for 15 min at a loading dose of 0.5 μg/kg starting from the time point before anesthesia induction followed by a continuous infusion of 0.2-0.5 μg·kg -1·h -1 until the end of operation. VCV mode was used in group V, and PC-VG mode was used in P and PD groups, ventilator settings were adjusted to the mode with a tidal volume 6-8 ml/kg, respiratory rate 15-25 breaths/min, inspiratory/expiratory ratio 1∶2, oxygen flow rate 2 L/min, fraction of inspired oxygen 60%, and P ETCO 2 was maintained at 35-40 mmHg during mechanical ventilation in three groups. At 5 min before pneumoperitoneum (T 0), 10, 60 and 120 min of pneumoperitoneum (T 1-3) and 10 min after release of pneumoperitoneum pressure (T 4), peak airway pressure (Ppeak), mean airway pressure (Pmean), compliance of lung (C L) and airway resistance (Raw) were recorded, alveolar-arterial oxygen partial pressure difference (PA-aO 2), oxygenation index (OI), and respiratory index (RI) were recorded. The occurrence of pulmonary complications was recorded within 7 days after operation. Results:Compared with V group, the Ppeak and Raw were significantly decreased and C L was increased at T 1-4, and PA-aO 2 and RI were decreased and OI was increased at T 3, 4 in P group and PD group ( P<0.05). Compared with P group, no significant change was found in the parameters of respiratory mechanics mentioned above at each time point ( P>0.05), and PA-aO 2 and RI were decreased and OI was increased at T 3, 4 in PD group ( P<0.05). There was no significant difference in the incidence of postoperative pulmonary complications among the three groups ( P>0.05). Conclusions:PC-VG combined with dexmedetomidine has a certain lung-protective effect in pediatric patients undergoing laparoscopic surgery.