Dexmedetomidine Improves Peripheral Perfusion Under Pneumoperitoneum In Laparoscopic Surgery

ObjectTo evaluate the effect of Dexmedetomidine infusion on Peripheral Perfusion under pneumoperitoneum in Laparoscopic surgery patients.MethodsThirty patients were divided into three groups (n=12) according to random number table, low pressure group (group L), high pressure group (group H) and dexmedetomidine with high pressure group (group DH). For group L intraoperative pneumoperitoneum pressure were set to (8～10) mmHg, while for group H and DH, set to (14-15) mmHg. Dexmedetomidine 0.5ug·kg-1 were infused to the patients in group DH 20minutes before induction of anesthesia over 10 minutes. All patients had routine monitor for BP, ECG and ETCO2, and a special pulse oximetry sensor of NT1H was applied to a finger to monitor SpO2 and peripheral perfusion index (PPI). After pre-oxygenation for 3 minutes, patients were inducted with mtravenous propofol 2mg· kg-1, sufentanil 0.5 ug·kg-1, cis-atracurium 0.15mg·kg-1, and were intubated. Mechanical ventilation were set with tidal volume (8～10) ml·kg-1,10～12 beats per minute to control the peak airway pressure under 30cmH2O and ETCO2 at 30～ 40mmHg. Anesthesia were maintained with propofol (4～6) mg·kg-1·h-1 and remifentanil (0.2～0.4) ug·kg-1·h-1 infusion and sevoflurane (1-2)% inhale to keep BIS 40～50. Intravenous ephedrine 6mg may administered for hypotension (MAP <60mmHg), and atropine 0.5mg for bradycardia (HR<50/min). At the end of surgery, anesthetics were discontinued and patients were extubated after they resume orientation and obedience. PPI, MAP and HR were recorded upon induction (TO), 1min after induction (T1), skin incision (T2), 1min after incision (T3), upon pneumoperitoneum (T4), 1min and 2min after pneumoperitoneum (T5 and T6),1 min,3 min,5 min,7 min, 9 min and 11 min after head-up (reverse Trendelenburg) position (T7, T8, T9, T10, T11 and T12). The duration of anesthesia and surgery, the time from discontinues of the anesthetics to resume orientation and extubation were also recorded.ResultsThere were no significant difference amonge three groups regarding the patients’ characters. Surgical time was significantly longer (P<0.01) in group L comparing to that of group H and DH. Resume of orientation and extubation were significantly delayed in group DH (P<0.01) comparing to that of group H and L. In all groups, PPI were significantly increase after induction (T1) (P<0.01) comparing to the baseline TO, and returned to baseline after incision (T2,T3), reduced significantly after pneumoperitoneum (T6) (P<0.01) and further reduced after head-up position (T7-T12). Comparing among groups, PPI at T6, T12 were higher in group DH than that in group H (P<0.05). The PPI of group L were higher than that of group H at T7-T12 (all P<0.05). There were no significant difference of PPI between group DH and group L at any time point (P>0.05). The MAP had a similar change patent in all groups, reduced significantly after induction (T1-T12), further reduced after head-up positioning (T7). Comparing among groups, MAP in group DH were lower than those in group L and H at T7～12 (P<0.05 or 0.01). MAP in group H and group L had no significant difference at any time point (P>0.05). The HR had no significant difference among groups at any time.ConclusionDexmedetomidine infusion improved peripheral perfusion under high pressure pneumoperitoneum in laparoscopic surgery patients. The blood pressure may be slightly decreased during surgery but still in normal range. Reduced pneumoperitoneum pressure may also improve perfusion but may worsen surgical condition.