Enhanced postoperative recovery: good from afar, but far from good?
Authors: Kehlet H. 
Published: July 2021

Background. The main problems of the postoperative period include organ dysfunction (“surgical stress”), morbidity due to hypothermia, pain, hyper- or hypovolemia, cognitive dysfunction, sleep disturbances, immobilization, semi-starvation, constipation, thromboembolism, anemia, postoperative delirium and more. A multimodal approach to optimizing enhanced recovery after surgery (ERAS) includes improving the preoperative period, reducing stress and pain, exercise, and switching to oral nutrition. These measures accelerate recovery and reduce morbidity.
Objective. To describe the measures required for ERAS.
Materials and methods. Analysis of literature sources on this issue.
Results and discussion. The majority of postoperative complications are associated with the so-called surgical stress involving the release of stress hormones and the start of inflammatory cascades. The stress response is triggered not only directly as a result of surgery, but also as a result of the use of regional anesthesia and other medications. Mandatory prerequisites for ERAS include procedure-specific dynamic balanced analgesia, as well as patient blood management (PBM). The latter consists of hematopoiesis optimization, minimization of bleeding and blood loss, improvement of anemia tolerability. The presence of preoperative anemia before joint replacement significantly increases the number of complications in the 30-day period (Gu A. et al., 2020). Preoperative anemia also leads to the unfavorable consequences of other interventions, which underlines the need to detect and treat it early. An optimal infusion therapy with a positive water balance (1-1.5 L) is an integral component required for ERAS. Balanced solutions should be used; opinions on the use of colloids are contradictory. Venous thrombosis remains a significant problem, as immobilization is an important pathogenetic mechanism. The question of optimal prevention of this condition has not been clarified yet. In 40-50 % of cases after major surgery and in <5 % of cases after minor interventions, the patient develops postoperative orthostatic intolerance. The mechanisms of the latter are a decrease in sympathetic stimulation against the background of increased parasympathetic stimulation; the effects of opioids and inflammation are likely to play an additional role. Preventive methods have not been definitively established, α1-agonists (midodrine) and steroid hormones are likely to be effective. Unfortunately, for most of these problems, there is a gap between the available scientific evidence and the actual implementation of the recommended procedures. The ERAS Society has created recommendations for the management of patients, undergoing a number of surgical interventions (gastrectomy, esophagectomy, cesarean section, oncogynecological surgeries, etc.). For example, recommendations for colon interventions include no premedication and bowel preparation for surgery, use of middle thoracic anesthesia/analgesia, administration of short-acting anesthetics, avoidance of sodium and fluid overload, use of short incisions, absence of drainages, use of non-opioid oral analgesics and non-steroid anti-inflammatory drugs, stimulation of intestinal motility, early removal of catheters, oral nutrition in the perioperative period, control of surgery results and adherence to treatment. Knowledge of procedure-specific literature data and recommendations, multidisciplinary cooperation, monitoring, identification and sharing of methods that have economic advantages are necessary for the ERAS improvement. Outpatient surgery and one-day surgery are becoming more and more common. In a study by N.H. Azawi et al. (2016) 92 % of patients after laparoscopic nephrectomy were discharged home within <6 hours after surgery. Repeated hospitalizations of these patients were not recorded. In a study by G. Ploussard et al. (2020) 96 % of patients after robotic radical prostatectomy were discharged home on the day of surgery; 17 % required re-hospitalization. Early physical activity is an important component of rapid recovery after surgery. There is an inverse relationship between the number of steps per day and the severity of pain after a cesarean section. Despite a large body of literature on the subject, large-scale randomized trials and definitive procedure-specific recommendations are still lacking. This justifies the need for thorough pathophysiological studies and, once completed, randomized controlled or cohort studies. The objectives of these studies should include clear clarification of the pathophysiology of postoperative organ dysfunction, the introduction of a procedure-specific and evidence-based set of perioperative measures, monitoring of purely surgical and general medical consequences of surgeries, identifying areas for improvement and finding new treatment and prevention strategies.
Conclusions. 1. Multimodal approach to ERAS optimization includes improvement of the preoperative period, reduction of stress and pain, physical activity, transition to oral nutrition, etc. 2. Procedure-specific dynamic balanced analgesia, PBM, optimal infusion therapy with a positive water balance are the mandatory prerequisites for ERAS. 3. For the majority of problems of the perioperative period, there is a gap between the available scientific evidence and the actual implementation of the recommended procedures. 4. New preclinical and clinical studies are needed to form definitive guidelines for the management of patients in the perioperative period.