tumor of prostate is the one of most common disease in elderly patients over 60 years. Open radical prostatectomy has been the reference standard for treatment of prostate cancer. Recently, surgical approaches to prostate cancer treatment have been replaced by minimally invasive techniques such as LRP and RALP. Previous study has shown RALRP improves clinical effect comparing with open radical prostatectomy and LRP, the time of operation of RALRP was longer than that of LRP from 2000 to 2005, but the time of operation of RALRP was shorter than that of LRP from 2014 to 2016. Meanwhile, our study found that the Tp, To, Ta of RALRP was significantly longer than that of LRP, which may be related to the surgical skill of the surgeon. Because our hospital started using Da Vinci surgical operating system for RALRP only in September 2017, and surgeon have more than ten years of experience with hundreds of LRP operations, that may help to explained whythe dosage of propofol and remifentanil were higher in the group RALRP than that in the group LRP.
A study has shown that the incidence of postoperative delirium in robotic assisted esophageal surgery was about 30%, significantly lower than that in open surgery . Our study found that the incidence of postoperative delirium in the group RALRP was 17.3%, which may be due to the need for single lung ventilation during esophageal surgery, which could increase the incidence of postoperative delirium. Meanwhile, our study showed that the incidence of postoperative delirium in group LRP was 32.4% significantly higher than that in group RALRP(17.3%). Tr in group RALRP and LRP was 31.52 ± 9.89 and 38.65 ± 16.32 min, respectively, which indicated that RALRP could be significantly reduced the incidence of postoperative delirium and recovery time.
Similar to LRP, RALRP requires insufflation of the abdomen with carbon dioxide (CO2) pneumoperitoneum and the steep Trendelenburg (ST) position to create an optimal surgical space, which are associated with a number of problems, including hypercapnia, brain edema and other complications. These complications affected the postoperative recovery and increase the incidence of postoperative delirium. Rapid infusion and absorption of CO2 and high pressure pneumoperitoneum increased intraabdominal pressure, leaded to internal and external organs ischemia, increased postoperative pain, and resulted many physiological disorders . Meanwhile, CO2 harmed organs by promoted oxidative stress and inflammatory response. Studies have shown that the incidence of postoperative delirium and cognitive dysfunction may be related to the inflammatory response of the central nervous system [15, 16]. Reducing IAP and PaCO2 could reverse this adverse effect. Trendelenburg position could aggravate the mentioned adverse effect and change the intracranial hemodynamics subsequently increased intracranial pressure. Our study has found that post-pneumoperitoneum PaCO2 and IAP in group RALRP were significantly lower than those in group LRP, which may be the explanation for the lower incidence of postoperative delirium and the short recovery time in group RALRP. Zhou et al. showed that A small dose of mannitol can effectively improve cerebral oxygen metabolism and protect cognitive function after the operation. author work in the same department as Zhou’s. When patients had severe delirium after surgery, we first gave them a small dose of mannitol. We also sedated patients with propofol and gradually remove the endotracheal extubationendotracheal tube after the delirium remission. Tr in the group RALRP was significantly lower than that in the group LRP, which was associated with the low incidence of postoperative delirium in the group RALRP. However, there was no difference of Te between RALRP and LRP, mainly because all patients were removed trachea tube with completely awake and without delirium. Meanwhile, the patients left the post-anesthesia care unit with the same standards, the vital signs patients after endotracheal extubation were similar, and the dosage of vasoactive drugs in the two groups were similar.
There are many factors affecting delirium after surgery, and pain is one of the factors . Studies have shown that low IAP can reduce pain in patients during laparoscopic surgery [19–21]. Our study found that the IAP of patients in the group RALRP was significantly lower than that in the group LRP(12.72 ± 1.87 VS 13.37 ± 1.12 mmHg, P < 0.05), so the patients in group RALRP suffered less postoperative pain, resulting lower incidence of operative delirium. Meanwhile, through binary logistic regression analysis, our study found that each unit of IAP increased the postoperative delirium rate by 1.66 times.
RALRP is similar to LRP, surgeon need to use CO2 to provide effective operating space. But the difference between the two procedures is that the computerized electromechanical controls give the surgeon much more precision and stability for the dissection of critical structures, and the console has tridimensional vision, which provides depth of field and helps immensely with regard to orientation and surgical precision. Therefore, compared with LRP, RALRP needs a lower IAP to satisfy the surgeon's requirements for surgical space, which is the reason for why IAP in the group RALRP was significantly lower than in the group LRP. Our study did not find differences in postoperative hospital stay and blood loss between the two groups, which was different from other studies [1, 22]. The overall cost of patients in the RALRP group is higher than that in the LRP group, which may hinder the development of RALRP in China.