22 Junio 2015

Lectura crítica a “Introducing an enhanced recovery after surgery program in colorectal surgery: A single center experience” Stefano Bona, Mattia Molteni, Riccardo Rosati, Ugo Elmore, Pietro Bagnoli, Roberta Monzani, Monica Caravaca, Marco Montorsi, Department of General Surgery, University of Milan School of Medicine, Humanitas Research Hospital, 20089 Rozzano, Milan, Italy

By Mihai Paduraru. PhD, MSc, MD – Servicio de Cirurgia General y Digestiva. Hospital General de Tomelloso. España.

The article defines itself as a ‘prospective single center cohort study’ and therefore has been evaluated against the criteria set out in the CASP Cohort Study Checklist (2013).
The title of this paper highlights some of the ambiguity in the focus of this study. It implies a reflection on the experience that took place rather than a more solid scientific approach. The authors do give an aim to the study: ‘…the prospective evaluation of an ERAS protocol that includes full application of all ERAS principles, through the progressive steps of its implementation at our Institution, (… from “pilot study” to “standard of care”)’.
It is clear with regard to the population to be studied and the outcomes to be measured: length of postoperative hospital stay, re-admission rate, compliance to the (ERAS) protocol and morbidity by comparing results from the pilot and ‘shared’ phases of the implementation, thus with the aim of highlighting the benefits and issues incurred.

The rationale for the study is explicitly stated in that, despite there being a large body of evidence to support the implementation of ERAS, there is still a reluctance in practice to implement due to such cultural factors as fear of change structurally/organizationally.(‘The question seems no longer to be whether colorectal surgery according to “enhanced recovery after surgery” (ERAS) principles or to traditional care is better, but rather how to improve the approach and facilitate its deployment.’) Much of the detailed background to the study is found in the ‘Discussion’ and would be better for the paper’s structure for it to be in the ‘Introduction’.

The ‘recruitment’ of the cohort is implied from the ‘inclusion criteria’ that all patients over the age of 18 undergoing elective colorectal laparoscopic resection surgery and who consented to take part (‘and judged able to understand the requirements of the study’), were involved in the trial. It is not clear or explained what is meant by: ‘judged able to understand the requirements of the study’; how objectively this was achieved and what patients were indeed told; neither is it clear how many patients were excluded as a result of this (or as a result of the other stated ‘exclusion’ criteria), therefore it is not possible to accurately assess whether the recruitment methods were wholly acceptable or if the population studied was representative of that as a whole. The authors state that traditionally their hospital performs 300 colorectal resections annually (the majority of which are via laparoscopy), however, only data from 190 patients is used in the study, with no explanation as to why there is a difference in these numbers.
The inclusion criteria, when extended beyond the pilot group, are also extended (to include ASA score of V and some emergency cases). Again, no rationale is given for this but these new factors prohibit a direct comparison with the pilot group and make it difficult to measure the accuracy of the results against the outcomes set. The lack of clarity in these issues opens the study up to selection bias and questions its validity.

The methodology of the study lacks some rigor. All patients were exposed to the same procedures as specified by ERAS and were therefore objective; however, where there was no compliance to the protocol, these factors were not measured in relation to the outcomes. Since both groups were not identical from both the patient profile and the experience/practice of the medical personnel point of view, the measurement of the outcomes cannot be strictly accurate. The issue of the pilot phase being conducted in a ‘specialist’ unit with (and ‘due to’) dedicated staff with sympathetic training (e.g. Nurses experienced and focused on ‘fast tracking’ a patient), is an important factor – closer to clinical trial conditions. The authors discuss these but do not account for them as confounding factors statistically, thus the results are open to bias.
The trail is not consistent in the period of exposure between the two groups (21 months in the pilot study and 7 months for wider implementation), but the significance of this is not discussed. The authors compare results between the two groups in terms of outcomes re: recovery rates and readmissions, presumably with the view of illustrating the benefits and consequences of compliance/non compliance with ERAS. It is possible to argue that the pilot needs longer to implement and once established, could be easier to introduce to the rest of the hospital. Conversely, taking into account the number of staff in the rest of the center and the training required for effective implementation, the second period should have been longer than the first. Indeed, it could be argued that if this part of the study had been longer, then overall results might have been better due to compliance though better understanding and practice. Follow up was undertaken at 7 days and then 1 month, which is standard procedure and is deemed sufficient.
Statistical analysis of the results is not rigorous and there is no description of how results were obtained or which tests were used to analyze the results. There are no tables depicting the breakdown of results or the differences between patients, treatment and personnel. Only 3 graphical representations are offered and these are not easy to interpret. The authors use mean and median data in the text but only median on the graphs, leading to initial confusion. Differences in stated outcomes are expressed in terms of percentages but are not given P values to identify any statistically significance and Confidence Intervals are not set in order to establish the validity of the results. Poorer results are associated with non compliance but are not strictly analyzed for this, indeed the authors state that their results ‘seem’ to fit this hypothesis but provide no strong evidence.

Other than precise detail of the ERAS protocols applied, the authors do not systematically detail how implementation from ‘pilot’ to ‘system wide’ application was planned and undertaken; nor how staff were trained; nor of all the precise difficulties encountered during implementation and why some aspects of the protocol were harder to implement than others. All these aspects surely would be of benefit to the clinical community, especially since implementation is a focus of the trial. This study does not adequately expose these issues nor give any attempt to guide future trials with the limitations/achievements of their study, despite the ‘Primary Endpoint being: ‘… the description of the results and the identification of critical issues of large scale implementation of an ERAS program in colorectal surgery emerged in the experience of a single center’. The Secondary Endpoint is: ‘…the identification of interventions that have been proven to be effective for facilitating the transition from traditional care pathways to a multimodal management protocol according to ERAS principles in colorectal surgery at a single center.’ They only give some examples in the discussion, such as dedicated space being provided for better mobilization of patients.

The study gives results of pre ERAS procedures and compares these with those after implementation, as well as comparative data between pilot, second and third stage implementation. ERAS has already been proven effective in trials and the results of this study show that ERAS is more effective in the pilot stage but still reduces length of hospitalization (mean 8 days from 10). Statistical comparisons for morbidity and readmission are given for the 3 stages but not for the period before ERAS implementation and so consistent comparisons cannot be made. Again, the lack of tabulated data makes these results harder to find.

The authors claim: ‘Our results confirm that introduction of an ERAS protocol for colorectal surgery allows quicker postoperative recovery and shortens the length of stay compared to historical series.’ But this claim is weakened because the purpose of the study is confusing: evidence is provided for the validity of ERAS but is not consistent; the comparison of pilot study results against wider implementation, show that a controlled environment is more effective and yet the pilot is not strictly comparable as it varies in key aspects from the wider study; the pilot is also used to serve as an incentive for this wider implementation and to provide evidence for the benefits of full implementation, the authors are not rigorous enough however in detailing the implementation methods to enable other hospitals to benefit from these.

The authors cite 2 other studies already identifying that there is decreased compliance to protocols when undertaking wide scale application and the results from this study demonstrate the same, and argues for compliance in order to reduce morbidity based on some, (not rigorous) evidence of a correlation between the two. This is useful information for further investigation.

The study provides no new evidence but does serve to demonstrate that, firstly a centre has adopted ERAS protocols as its standard practice, and secondly, even though there is not total compliance and therefore results show less positive outcomes overall in comparison to those of a designated pilot group of patients, they are better than those achieved without application of ERAS, thus dismissing some of the arguments against wide scale implementation.”