Background: Enhanced recovery after surgery (ERAS®) is increasingly finding its way into clinical practice. ERAS® protocols have not been universally adopted, and they have often been criticized for being difficult to implement. So, the question for more tailor-made approaches arises. Methods: We conducted a literature search on March 16, 2022, using the following search string, which was modified to fit the input of each of the queried databases: (“ERAS®” or “enhanced recovery after surgery” or “fast recovery” or “fast track”) and (“tailored” or “individual”). Results: Despite the massive increase in general hits on the subject, stratification according to phenotypic characteristics such as age or a classification according to disease patterns in the sense of specific guidelines is still fundamentally apparent. Evidence suggests that generic protocols can be followed by almost all patients. Prehabilitation, in particular, can be used as an adaptive tool. Conclusion: ERAS® works only in the totality of its tools and can be followed by almost all patients. Prehabilitation is more adaptive and can also increase adherence to ERAS® protocols. A tailored program outside of disease-specific pathways does not seem to be useful.

Although the first cornerstones of the topic were published more than 20 years ago by Kehlet et al. [1], protocols for “fast track” or “enhanced recovery after surgery (ERAS®)” are just starting to find their way into everyday clinical practice. Current searches for publications addressing ERAS® have increased substantially in recent years. Of the more than 1,700 published articles (using the search terms enhanced recovery after surgery or fast-track surgery) published since 2000,; half were published after 2016. Catalyzed by pioneers and associations such as the ERAS® Society, the clinical effectiveness of the ERAS® elements has now been backed up with robust evidence.

The more recent scientific research in this area focuses on the mechanisms by which (ERAS®) protocols achieve the desired homeostasis of physiological processes. Due to the broad spectrum of surgical interventions on various organ systems, the question of tailor-made protocols arose. To date, protocols have been developed for various disease- and surgery-specific scenarios. Processes such as the systemic inflammatory and catabolic response of various organ systems to surgery, deranged fluid homeostasis and vascular responsiveness, anemia, and pain pathology were considered for specific interventions to be included in protocols. This comprehensive approach gave rise to the first ERAS® protocol more than 2 decades ago for patients undergoing colorectal surgery, and its success has been documented in numerous publications that have demonstrated reduced complication rates and faster recovery. In addition to the constantly growing number of items in the individual protocols and their corrections, completely new categories are also emerging, such as the optimization of patients before an operation, so-called prehabilitation. Over the years, an increasing number of surgical specialties have adapted and adopted ERAS® Society Guidelines. Currently, there are 21 ERAS® Society Guidelines covering various surgical specialties and subspecialties.

Despite the aforementioned benefits, ERAS® protocols have not been universally adopted, and they have often been criticized for being difficult to implement. The implementation of an ERAS® protocol is complex and requires a multidisciplinary team that is open to innovation and willing to rethink long-established procedures. Due to the numerous personnel and procedural changes involved in this implementation, there are many problems and barriers that need to be overcome. The ERAS® nurse plays a central role in the implementation of an ERAS® program, assuming both specific patient-related and global coordinating tasks. The costs of a nurse are country-specific. There are many analyses that clearly prove a reimbursement through, e.g., shorter hospital stays [2].

Patients in an ERAS® program follow a specific protocol of elements of care. Studies have demonstrated a correlation between adherence to the components of the enhanced recovery protocol and superior outcome [3]. Critics have argued that a successful ERAS® program is difficult to achieve and may not be appropriate for all types of patient [4, 5]. However, as evidence for components of the ERAS® protocol change, it may be that a more flexible and individualized approach should be considered.

Literature Search

Based on the published guidelines provided by the ERAS® Society, we conducted topic-related searches for the field of visceral interventions on PubMed. We conducted a literature search on March 16, 2022, using the following search string, which was modified to fit the input of each of the queried databases: (“ERAS®” or “enhanced recovery after surgery” or “fast recovery” or “fast track”) and (“tailored” or “individual”) Queried databases included PubMed/Medline, Web of Science, the Cochrane Reviews library, Embase, and CINAHL. Additionally, we queried the bibliographies of the guidelines for additional relevant articles.

Patient Tailoring in Context of an ERAS® Protocol

The terms stratified, personalized, tailored, or precision medicine all refer to the grouping of patients based on risk of disease, or response to therapy, using diagnostic tests or techniques. This approach provides an opportunity for patients and healthcare providers to benefit from more targeted and effective treatments, potentially delivering more healthcare gain and improved efficiency for the healthcare system. Initial groupings can be made by disease or phenotypic characteristics such as age or ethnicity. This stratification can continue up to molecular markers that can, e.g., influence drug therapies. In relation to the ERAS® protocol, individualization can take place at the first level through the disease-specific protocols. Each protocol itself consists of multiple items that can be added or omitted. In a theoretically continued concept, even the individual items could then be adapted to the patient again.

A practical example in Figure 1 shows the path of a patient with colorectal cancer. The first step is to assign the patient to the appropriate colorectal protocol. The current protocol contains 24 individual items. The literature shows positive effects of a protocol only if a protocol adherence of more than 70% can be achieved. There is no evidence regarding specific items that have to be fulfilled or not. In the third phase, the item of early postoperative mobilization is shown, where a time is required for the patient to spend out of bed. Here too, the individual items can be modified internally by, e.g., changing the required time. As the example shows, individual elements are already established for patients (allocation to specific protocols) and the system offers various options for further modifications.

Fig. 1.

Processes of an ERAS® protocol and possibilities of adaptation.

Fig. 1.

Processes of an ERAS® protocol and possibilities of adaptation.

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Are all the ERAS® care elements justified? It is still under debate which elements on the different ERAS® protocols are really necessary. In a review by Ahmed et al. [3], the protocols of the included studies vary from 5 to 17 items, while the official ERAS® guideline includes 24 items. A high number of items are criticized as too complex and difficult to implement. On the other hand, several publications have shown that the more ERAS® elements are in use, the better the outcomes [2, 6-9].

Disease-Related Stratification

Both in the literature and in our own understanding, the first stratification of patients is by underlying disease. This opinion is also reflected in the specific and published pathways of the ERAS® Society. The pathways for different interventions are the same in their basic structure. One main reason for this is the structured guideline development and update process. The fundamental premise of ERAS® is the incorporation of evidence-based practice, allowing modifications of certain aspects of the program as new data become available. For many cohorts of patients or conditions, little evidence is available. This automatically leads to the adoption of existing recommendations with strong evidence from other guidelines, which are then evaluated for the new cohort. The ERAS® program is divided into a preoperative, intraoperative, and postoperative phase. In the given spectrum of visceral interventions, the core elements remain unchanged. Further path-specific modifications arise from logical conclusions from clinical practice. The literature search with the aforementioned search terms yields 81 hits. In the area of full texts, protocols for previously unpublished and monitored disease groups can be found. Novak et al. [10], e.g., developed their own hand surgery program and found no difference for the collective in a randomized trial. It is important to note that the protocol does not have the structure, implementation, and evaluation of the ERAS® guidelines. Lyu et al. [11] first implemented the colorectal program in their center according to the official ERAS® Society Guidelines and transferred this to sarcoma patients without relevant adaptations. An initial evaluation showed a reduction in complications and hospital length-of-stay. An initial adjustment of the pathways is therefore made on the basis of the clinical picture and intervention-specific characteristics. For example, in oncological interventions, interferences with neoadjuvant and adjuvant concepts must be taken into account. Nevertheless, it would be wrong to call this rough classification tailor-made or patient-specific.

Classification according to Phenotypic Characteristics: Older Patients

Driven by demographic change, the stratification of patients according to age groups is of particular interest. The recurring question is whether an adaptation of the pathways for older patients with comorbidities is necessary. Where increased age itself in the past used to be a drawback for major surgical procedures, the number of surgical procedures performed on older patients increases nowadays. There is good evidence showing resections can be safely performed in selected elderly people [12, 13]. Compared with younger patients, older patients have a higher risk of morbidity and mortality after surgery [12, 14-16]. It is not proven if all elderly patients may be able to comply with the components of an ERAS® program, or if they have better or worse outcomes with such programs than younger patients. It may be argued that the elderly need strategies such as ERAS® to optimize speed of recovery and to avoid postoperative complications [4]. Wang et al. [17] evaluated elderly patients undergoing open elective colorectal cancer resection and could show that patients who were managed with the ERAS® protocol were discharged on average 2.5 days earlier. No data were reported on the rates of reoperation, readmission, or adherence to the ERAS® protocol. Several other (nonrandomized) studies demonstrated no difference in length of stay between elderly and younger cohorts undergoing colorectal resection with an ERAS® program [18-23]. Bagnall et al. [4] conclude in their systematic review that older patients can participate in an ERAS® protocol and benefit just as much as younger patients.

Modification of Individual Protocol Elements

Prehabilitation as a Tailor-Made Process within the Framework of Established ERAS® Protocols

Preoperative Condition of the Patient: Even in centers with established ERAS® protocols, complication rates of up to 45% are reported in colorectal surgery. Reasons for the poor results could be factors such as inadequately treated comorbidities or influences on the patient that already exist (long) before the operation [24-26]. While efforts have been made to address every ERAS® elements of the intraoperative and immediate postoperative period, the time frame from indication to a surgical procedure until the operation has received modest attention. This interval can be used to optimize patient health and prepare the patient for the postoperative recovery.

Functional capacity is the most studied outcome parameter in prehabilitation research. Functional capacity describes the ability of an individual to independently perform the activities of daily living. Since functional capacity is patient individual, it cannot be measured in a metric system (for example, the daily challenges of an older retired person cannot be compared to those of a working person). Functional capacity is therefore an integrated interaction of mental, cardiopulmonary and muscular attributes. This already results in the necessity of a multimodal prehabilitation that covers the areas of mental health, physical health, and nutrition [27-29].

Several meta-analyses [29, 30] and randomized trials [31, 32] have reported the benefits for prehabilitation programs. Only a few studies have identified clinical benefits with the use of prehabilitation in an ERAS® setting [33]. Gillis et al. [27] reviewed prehabilitation in the context of an ERAS® program and also showed complementary effects. While prehabilitation increases resistance to stress (surgery, chemotherapy, etc.) by increasing functional capacity, the approach of ERAS® is to attenuate the stress response itself and restore functional capacity.

Prehabilitation as a Mechanism to Increase Adherence to the ERAS® Protocol

The literature has shown that an ERAS® protocol can only achieve its positive effects if an adherence of at least 70% can be achieved. Ahmed et al. [3] investigated in a systematic review the impact of protocol adherence on the outcome of patients with colorectal resection. The authors were able to demonstrate a direct correlation between high adherence and good outcome. The fulfilment of all components of the ERAS® protocol, especially the physical parameters such as mobilization, requires a minimum functional capacity. Through the measures of prehabilitation and the consecutive increase in physical, mental, and nutritive capacities, the possibility of participating in the ERAS® protocol is also made possible. Due to the possible increase in adherence the effect on the outcome is potentiated (Fig. 2).

Fig. 2.

Prehabilitation and ERAS® as synergistic effects.

Fig. 2.

Prehabilitation and ERAS® as synergistic effects.

Close modal

Prehabilitation is currently an increasingly movement but lacks sufficient data to address the right patient population. Probably the elderly multimorbid patients benefit the most. The evidence in this regard is still the subject of current discussion. A good review was carried out within the framework of a Cochrane review [34].

Prevention Paradox in Relation of ERAS®

In a way, ERAS® is a form of prevention against postoperative morbidity. The prevention paradox was first formally described in 1981 by Rose [35]. The prevention paradox describes the seemingly contradictory situation where the majority of cases of a disease come from a population at low or moderate risk of that disease, and only a minority of cases come from the high-risk population (of the same disease). This is due to a low number of high-risk patients. Translated to our question of a more tailor-made program, we have to ask ourselves: What is more beneficial for the majority of our patients? A generic program in which many can participate or a specific, much more complex, tailor-made program for a few?

Special Attention to High-Risk Patients

Individual patient characteristics can influence the natural response to surgical injury, such that the response is impaired, exaggerated, or prolonged, and thus more likely to produce adverse outcomes [27]. Frailty itself is an independent risk factor for peri- and postoperative complications. The term should not be confused with age in this context. Frailty is characterized by a reduced reserve to tolerate complications [6]. Early identification of high-risk patients with appropriate scores that capture the patient’s risks holistically (e.g., including mental performance) is essential.

The patient group for whom preoperative conditioning is of particular importance is the functionally impaired high-risk patients with multimorbidity. A large randomized trial included randomized controlled and blinded 125 high-risk patients prior to major elective abdominal surgery with an age >70 years and/or an ASA score III/IV. Prehabilitation was individualized for 4 weeks. There were significantly fewer patients with severe postoperative complications in the prehabilitation group. The number of complications per patient and nonsurgical complications were also significantly lower (p = 0.001) [31]. These effects are much less evident in studies of fitter patient cohorts [36, 37]. This effect is confirmed in the ERAS® context. Patients who have the physical and psychological conditions to participate in an ERAS® pathway do not need specific prehabilitation. Patients with low or borderline functional capacity benefit from individual prehabilitation, which in turn enables them to participate in an ERAS® pathway.

ERAS® is a holistic program which is known to have a significant impact on postoperative morbidity. Its implementation requires the cooperation of many participants and the patient himself. The positive effects can only be seen when (almost) all items of a pathway are followed. Which item combinations are adaptable or even negligible is still the subject of scientific discussion. A program adaptation based on disease patterns seems logical and sensible. All other attempts in the literature to stratify specific patient groups have shown that most programs can be followed by all patients. ERAS® seems to be a one fits all instrument. The instrument of prehabilitation, which can be specifically adapted to the individual patient, is quite different. Even though the database is only moderate in this respect, synergistic effects of both programs are already evident. Two large randomized trials remain will be able to provide robust evidence in the future. In summary, a meaningful comparison of the literature would exceed the scope of this review. Prehabilitation seems to be able to make patients fit for ERAS®.

An ethics statement was not required for this study type; no human or animal subjects or materials were used.

The authors have no conflicts of interest to declare.

No funding available.

Steffen Seyfried performed the literature search; Patrick Teoule and Alexander Betzler critically reviewed the search results and analyzed the data. Christoph Reissfelder and Florian Herrle were involved in planning and supervising the work. Steffen Seyfried and Christoph Reissfelder drafted the manuscript and designed the figures. All the authors discussed the results and commented on the manuscript.

All data generated or analyzed during this study are included in this article. Further inquiries can be directed to the corresponding author.

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