ABSTRACT
Objective To evaluate the effect of perioperative administration of dexmedetomidine on postoperative ileus after laparocolectomy.Methods Sixty patients scheduled for abdominal surgery were randomly divided into two groups,30 in each group.Group D received dexme-detomidine administeration at a loading dose of 0.6 μg/kg for 10 minutes before induction,followed by an infusion rate of 0.5 μg·kg-1 ·h-1 to 30 min before the end of surgery.The control group re-ceived saline instead of Dex.After the surgery,Group C received intravenous sufentanyl 2 μg/kg, while group D sufentanyl 2 μg/kg combined with Dex 2 μg/kg.Heart rate variability (HRV)were detected before Dex infusion (T0 ),10 minutes after intubation (T1 ), 10 minutes after CO 2 insufflation (T2 ),1 hour after CO 2 insufflation (T3 ),10 minutes after CO 2 desufflation (T4 ),and 10 minutes after extubation(T5 ).The plasma concentrations of epinephrine(E)and norepinephrine (NE)were determined at T0 ,T3 ,T5 ,T7 and T1 0.The recovery of bowel function was evaluated in terms of the first time to fart and intake food.Results Compared with T0 ,HRV of power (TP), high-frequency (HF)power,low-frequency (LF)power and the ratio of LF/HF power were signifi-cantly decreased at T1-T4 in group C and at T1-T5 in group D.The plasma concentrations of E and NE were higher at T3 ,T5 ,T7 and T1 0 in both group C and group D (P <0.05).Compared with T1 ,TP, LF and the ratio of LF/HF were increased at T2-T4 (P <0.05).Compared with group C,TP,LF and the ratio of LF/HF were decreased at T2-T5 ,The plasma concentrations of E and NE were decreased at T3 ,T5 ,T7 and T10 and the time of first flatus was earlier(P <0.05).Conclusion The perioperative ad-ministration of dexmedetomidine during laparocolectomy facilitated the early recovery of bowel func-tion after surgery and decreasede the time of postoperative ileus.
ABSTRACT
BACKGROUND: This study was designed to assess the effects of pneumoperitoneal pressure (PP) and positional changes on the respiratory mechanics during laparoscopy assisted colectomy. METHODS: Peak inspiratory pressure, plateau pressure, lung compliance, and airway resistance were recorded in PP of 10 mmHg and 15 mmHg, with the position change in 5 steps: head-down at 20degrees, head-down at 10degrees, neutral position, head-up at 10degrees and head-up at 20degrees. RESULTS: When the patient was placed head-down, the position change accentuated the effects of pneumoperitoneum on respiratory mechanics. However, when the patient was placed in a head-up position during pneumoperitoneum the results showed no pattern. In the 20degrees head-up position with the PP being 10 mmHg, the compliance increased from 30.6 to 32.6 ml/cmH2O compared with neutral position (P = 0.002). However with the PP being 15 mmHg, the compliance had not changed compared with neutral position (P = 0.989). In 20degrees head-down position with the PP of 10 mmHg, the compliance was measured as 24.2 ml/cmH2O. This was higher than that for patients in the 10degrees head-down position with a PP of 15 mmHg, which was recorded as 21.2 ml/cmH2O. Also in the airway resistance, the patient in the 20degrees head-down position with the PP of 10 mmHg showed 15.8 cmH2O/L/sec, while the patient in the 10degrees head-down position with the PP of 15 mmHg showed 16.2 cmH2O/L/sec of airway resistance. These results were not statistically significant but still suggested that the head-down position accentuated the effects of pneumoperitoneum on respiratory mechanics. CONCLUSIONS: Our results suggest that respiratory mechanics are affected by the patient position and the level of PP - the latter having greater effect.