In this issue of Anesthesia & Analgesia, Banz et al. “… provide a survey of fields of opportunities for improving outcome after major surgery.”1 In particular, they review the pathophysiologic considerations. They start by reminding us that despite patients having worse clinical and pathologic characteristics, outcomes are improving. Elective surgical patients are not sick and there is no need for them to get sick. Postoperative complications can be and should be completely avoided. An elective surgical procedure is not an illness but rather a marathon or a big hill. Patients are physiologically and emotionally challenged by trauma, inflammation, immunomodulation, pain, and any iatrogenic harm. A major determinant of outcome is their ability to rise to the challenge that they are presented with. We now have increasingly sophisticated strategies to minimize the challenges (i.e., shorten the marathon or reduce the size and slope of the hill).
Modern perioperative care pathways have 3 broad strategic aims: (a) to modulate inflammation, (b) to minimize pain, and (c) to avoid iatrogenic harm. Over the last few decades, we have amassed an increasing understanding of the importance of balancing pro- and antiinflammatory responses to pathologic insults such as trauma or infection. We understand that excessive inflammation causes harm, but some inflammation is absolutely necessary to enable effective healing. As detailed in the article by Banz et al., modulating and immunomodulating strategies are now routinely used, such as the increasing use of minimally invasive surgery and optimizing oxygen delivery and tissue perfusion by using a goal-directed approach.2 A grayer area is the use of antiinflammatory drugs such as steroids. As our understanding of biology grows, options for therapeutic intervention and particularly drug intervention will increase. We can anticipate accelerated developments in this area, because a link has now clearly been demonstrated between systemic inflammation and postoperative cognitive dysfunction.3 Other potential areas for immune-modulation include the possibility of preemptive active or passive immunization of patients who have weakened or impaired natural immunity.4,5
Minimization of pain has always been at the heart of perioperative care, but the choice of therapeutic drugs has in reality changed little over the last 40 years. What has changed is the way in which we use the drugs. The increasing use of a multimodal approach and regional techniques that use ultrasound-guided catheter placements have improved the provision of postoperative pain relief. However, the biggest change has been the use of effective pain minimization to facilitate immediate postoperative mobilization. There is no doubt that achieving effective pain relief is much easier with minimally invasive surgical techniques such as laparoscopic and/or robotic surgery.
Probably the biggest change in perioperative care in the last decade has been the increased awareness of, and avoidance of, iatrogenic harm. We now recognize that many of the traditions of perioperative care were not evidence based and caused more harm than good, approaches such as dehydration and starvation, the use of bowel preparation, the use of premedicating drugs and long-acting anesthetic drugs, enforced bed rest and nil-by-mouth postoperatively, routine placement of nasogastric tubes and percutaneous drains, salt and water overload, and the use of long-acting opiate drugs to relieve pain. We can add to this list the use of long midline incisions when smaller lateral incisions or laparoscopic techniques can be used to achieve the same goals.
As concluded by Banz et al., bundles of care and pathways are undoubtedly the way forward. Much progress has been seen in this area, and the exemplar is the so-called “Enhanced Recovery” or “fast-track” approach to major surgery.6 Pioneered by Prof. Henrik Kehlet and now increasingly widely adopted throughout the world, Enhanced Recovery is a multimodal, multiprofessional, best-evidence-based approach to the care of the patient undergoing elective and increasingly emergency major surgery. Many of the pathophysiologic issues presented by Banz et al. can be addressed by using the Enhanced Recovery approach. The process is driven by a more detailed understanding of the pathophysiology of postoperative morbidity; interventions that may improve outcome have been adopted piecemeal as they become available and have been packaged in the care process.
In some places, an Enhanced Recovery program has become the norm rather than the exception. Many people now ask themselves, “Why wouldn't I use an Enhanced Recovery approach for this patient?” as opposed to “Why should I?” In England, the National Health Service supported a national program to rollout “Enhanced Recovery” starting in 2009 and an accelerated rollout in 2010.a. The program is continuously refined and monitored, and the preliminary results are already demonstrating significant reductions in complications and length of stay in the 4 surgical areas in which it is primarily being tested (colorectal, musculoskeletal, gynecologic, and neurologic). We are currently aware of >100 programs running in England.
The final major change that we have seen in recent years is a more sophisticated approach to the postoperative care environment, with patients being triaged depending on the size of the challenge they face and their ability to rise to that challenge. In many countries, we have seen increased use of intensive care facilities, targeted at the higher-risk patients, to allow the continued use of the strategies introduced in the intraoperative period. The increased use of postanesthesia care units or overnight enhanced recovery wards has allowed 6 to 24 hours of continuation of everything that has been described above. Certainly in our own institution, after a long battle, we were given the green light to open a larger postanesthesia care unit, and we have clearly demonstrated a decrease in both morbidity and mortality, thus reduced length of stay and overall intensive care unit bed utilization.
For most of us, what I have described thus far is now routine practice and thus a “normal day at the office.” Therefore, for many of us, the area that offers the greatest potential for improving outcome after major surgery is determination and modulation of fitness for surgery, i.e., carefully matching patients' ability to rise to the challenge with the challenge they are presented with. It has been said that morbidity and mortality after elective surgery are simply manifestations of the failure to accurately identify and then modify risk. We must remind ourselves that the patient presenting for elective surgery still has 3 options:
- To proceed with the planned surgery, with the effective application of the risk minimization strategies detailed above.
- To go for a lesser operation and thus to try and minimize the challenge to a level that allows the patient to survive, or rather to provide a challenge that is appropriate for the individual patient. We cannot all run a marathon, but many of us could walk one.
- The third and most important option to consider is that no surgery takes place at all.
The ability of an individual to tolerate the surgical challenge is what we have traditionally referred to as “Fitness for Surgery.” For a long time, we have recognized that there are 3 major determinants of an individual's ability to tolerate major surgery: their age, their comorbidities, and their functional capacity. Their age, per se, does not mean patients are less fit for major surgery, but with increasing age there is, inevitably, an increasing incidence of comorbidities and reduced functional capacities, but with highly individual variations. As Banz et al. point out: “While a patient's age cannot be changed, an in-depth understanding of the altered physiology associated with increased age may help to develop better care …” What is less well understood, or routinely evaluated, is an individual's reaction to an inflammatory stimulus and/or their immune status, e.g., baseline levels of inflammation as determined by high-sensitivity C-reactive protein or markers of innate immunity such as the measurement of natural antibodies.4,5,7
There are increasingly sophisticated efforts to determine risk in the preoperative period. However, at least in the National Health Service in England, I think the timing of preoperative evaluation is misplaced if we are to act on what is already known about factors that determine outcome. A typical pathway for our patients would be that they would be referred for a surgical opinion by a community doctor. The surgeon would make a decision as to whether surgery could help, and then a date would be booked; after this, the patient would be referred to the preoperative assessment clinic. There is a possibility that the community doctor may have performed some form of triage, i.e., may not be referring some patients for a surgical opinion because they appear to be unfit for surgery, thus denying them expert preoperative assessment.
There is no doubt that specialist preoperative clinics have proven to be effective in reducing the number of same-day cancellations; what is less clear is whether they have effectively improved overall outcome. Our own clinic routinely uses risk scores and objective determination of fitness using cardiopulmonary exercise testing, and has demonstrated that it can improve triage and the use of postoperative resources and thus reduce complications and length of stay. But, overall, I believe the timing is wrong. Because preoperative assessment occurs after the initial surgical evaluation and offer of an elective procedure, the patient is already on a path to surgery that is much harder to deviate from. There is now little time to modify risk in ways proposed by Banz et al. or to easily change course. I think we should change the timelines, as has already happened in some places. I think the initial referral should be to a specialist clinic that evaluates risks and sets out a plan for the modification of risk. A simple risk evaluation tool can be used to triage patients in the first instance, then all but the young, comorbidity-free individuals could undergo objective determination of fitness and be prescribed lifestyle changes, such as exercise and diets, with counseling regarding stopping smoking and reducing alcohol use. Anemia, hypertension, and diabetes could all be investigated and modifications made before referral to the surgeon. The surgeon would then be able to review a patient with all the information necessary to counsel them with regard to the 3 major options: the ideal surgery for fit patients, modified surgery, or no surgery for the “unfit.” If the final outcome was to be no surgery, the screening efforts with regard to determination of fitness and lifestyle changes and investigation and treatment of common abnormalities would not be wasted. Indeed, over time, these evaluations and interventions could and probably should take place in the family doctor's office. Using this model, once the patient has seen the surgeon, he or she can start down the path of a truly informed consent process. The 3 options could be offered from the outset, and patients can consider the 3 options within the context of a true understanding of their own potential risks and their determination and willingness to modify risk factors (e.g., lose weight, get more exercise, and stop smoking), as detailed by Banz et al.1,8
Name: Michael Mythen, MD
Conflicts of Interest: I am employed part-time by the UK Department of Health as a National Clinical lead of their Enhanced Recovery Partnership Programme. My Department has received grants from Smiths Medical and Deltex Medical. I have received travel expenses and honoraria from Baxter, BBraun, and Fresenius-Kabi. My Department runs a number of educational meetings that are supported in part by Industry (declared on a meeting-by-meeting basis).
a For more details see http://www.improvement.nhs.uk/cancer/TransformingInpatientCare/EnhancedRecoveryPartnershipProgramme/tabid/98/Default.aspx. Accessed November 11, 2010.
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2. Lees N, Hamilton M, Rhodes A. Clinical review: goal-directed therapy in high risk surgical patients. Crit Care 2009;13:231
3. Wan Y, Xu J, Meng F, Bao Y, Ge Y, Lobo N, Vizcaychipi MP, Zhang D, Gentleman SM, Maze M, Ma D. Cognitive decline following major surgery is associated with gliosis, beta-amyloid accumulation, and tau phosphorylation in old mice. Crit Care Med 2010;38:2190–8
4. Bennett-Guerrero E, Ayuso L, Hamilton-Davies C, White WD, Barclay GR, Smith PK, King SA, Muhlbaier LH, Newman MF, Mythen MG. Relationship of preoperative antiendotoxin core antibodies and adverse outcomes following cardiac surgery. JAMA 1997;277:646–50
5. Bennett-Guerrero E, Panah MH, Barclay GR, Bodian CA, Winfree WJ, Andres LA, Reich DL, Mythen MG. Decreased endotoxin immunity is associated with greater mortality and/or prolonged hospitalization after surgery. Anesthesiology 2001;94:992–8
6. Kehlet H, Wilmore DW. Evidence-based surgical care and the evolution of fast-track surgery. Ann Surg 2008;248:189–98
7. Ackland GL, Scollay JM, Parks RW, de Beaux I, Mythen MG. Pre-operative high sensitivity C-reactive protein and postoperative outcome in patients undergoing elective orthopaedic surgery. Anaesthesia 2007;62:888–94
8. Myers JN, White JJ, Narasimhan B, Dalman RL. Effects of exercise training in patients with abdominal aortic aneurysm: preliminary results from a randomized trial. J Cardiopulm Rehabil Prev 2010;30:374–83