Perioperative care and enhanced recovery

Patient counselling

Patient counselling is about more than explaining the operation and the probable outcome, including any risk of complications. It is the key opportunity to make sure the patient realises what the perioperative course will entail and what his/her daily targets should be in terms of mobilisation, drinking, eating and so forth. ^{, ,} Counselling should be commenced at the preoperative out-patient clinic, with written or audio-visual information available for patients to review at an early stage to allow adequate familiarisation before surgery. The patient’s own part in his or her recovery should be emphasised and is an important factor in achieving compliance. This area is poorly suited for a randomised trial, and it would be unethical to attempt one. It is, however, an intervention with collateral benefits and without known side effects although it requires some extra time.

Preoperative nutrition and immunonutrition

Preoperative weight loss is a robust and strong predictor for adverse surgical outcomes. Even as little as 5% weight loss is a significant risk factor. The ESPEN criteria for malnutrition is defined as BMI of < 18.5 kg/m ² or weight loss > 10% (or > 5% over 3 months) and reduced BMI (or a low fat-free mass index). Weighing the patient and comparing the results with patient-reported premorbid weight is sufficient and as a predictor probably as valid as more complex nutritional risk assessment tools. While preoperative dietary interventions can help the patient to regain lost weight before surgery, it is less clear whether this affects postoperative risk or is merely alleviating symptoms. Intravenous nutrition, enteral tube feeding and oral supplements (sip feeds) have all been evaluated as interventions to attenuate patient risk for complications following major surgery and in general they are recommended. Numerous studies suggest a beneficial effect in malnourished patients, but double-blinded trials with adequate control groups are few. Importantly, providing nutrition is a consistent intervention that can be blinded and placebo-controlled in randomised controlled trials (RCTs), and in conditions suitable for optimal design we should accept nothing less. It appears prudent to provide nutritional support to grossly malnourished patients, orally if possible; enteral if oral is not feasible; and parenteral if the gut is not working. For patients with only mild malnutrition, the rationale is mainly supported by uncontrolled or open-labelled trials or trials measuring surrogate endpoints. Weight gain is achieved consistently in these studies, but lowered postoperative risk has not been documented in a reproducible manner.

Additional provision of immune-enhancing formulas like arginine or glutamine has been supported by several trials and international guidelines. ^, Immunonutrition (IN) is particularly aimed at reducing infectious complications. However, there are few double-blinded trials with isonitrogenous control groups measuring clinical outcomes. The most recent ERAS guidelines do not recommend the routine use of IN, ^, and several recent high-quality trials in high-risk patients have failed to show any benefit.

Cessation of smoking

Smoking negatively affects oxygen delivery to peripheral tissues, as well as those involved in an anastomosis. While chronic obstructive pulmonary disease (COPD), and risk of bronchial adenocarcinoma and cardiovascular disease will remain unchanged following 3 weeks of cessation from smoking, increasing evidence suggests that both oxygen delivery and pulmonary function can be improved by smoking cessation over as little as 3–4 weeks. Even in cancer surgery where delaying the operation will not be done lightly, allowing 4 weeks of complete cessation from smoking is probably wise in high-risk patients or planned high-risk anastomoses, e.g. low rectal, oesophageal or pancreatic head resections. It is a cheap and well-understood intervention, and it places the patient at the centre of the efforts to reduce risk.

Prehabilitation

Impaired functional capacity in elderly cancer patients is multifactorial and constitutes a risk during major surgery. Some of the causes are cardiovascular disease, COPD, lean muscle wasting and other elements of cachexia. Prehabilitation, which aims to increase functional capacity in patients with impaired functional capacity, hinges on the issue of whether elderly and frail patients can benefit from short-term exercise to such an extent that risk is reduced. Again, the presence of cancer—as is often the case—will usually not allow for extended periods of intervention. Cardiopulmonary function tests have been shown to correlate closely with risk for major morbidity following surgery ; and interestingly, Dunne et al. have shown that a short-term, hospital-based exercise program does indeed improve cardiopulmonary function for patients at risk. However, hospital-based daily training programs may have suboptimal compliance, and may not be feasible to implement.

Over recent years, prehabilitation programmes have become increasingly popular and are becoming a standard component of perioperative care in many countries. A combination of aerobic exercise, nutritional optimisation, inspiratory muscle training and resistance exercises have been shown to improve not only preoperative aerobic threshold as measured by cardiopulmonary exercise testing but also overall and pulmonary postoperative morbidity. ^, The precise optimum prehabilitation programme has not been established and heterogeneity exists in current programmes in terms of duration, make up and level of supervision. Additionally, the control groups in several of the recent RCTs include elements of prehabilitation and so overall impact has potentially not clearly been illustrated. It may also be that the real benefit of prehabilitation programs is harvested at a later stage: in the patients’ own communities and in the shape of protected physical independence and autonomy. In any case, preoperative programmes are becoming standard of care as the intuitive benefits have become recognised.

Anti-thromboembolic drugs in the perioperative period

An increasing number of patients take an increasing variety of anti-thrombotic drugs for primary or secondary prophylaxis. Due to uncertain enteral absorption and risk of intra- or postoperative bleeding, these drugs are transiently withheld during the perioperative period for a duration dependent on the type of surgery. Perioperative prophylaxis with low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH) varies depending on the indication for the patient’s use of prophylaxis, the drug in question and the magnitude of increased risk pertaining to the operation. Most departments will have access to local or national guidelines for each drug under several indications, and most cardiology departments will issue additional guidelines for prevention of thromboembolic complications in patients with coronary stents. The following section is intended as an overview and the reader is strongly advised to consult national and local guidelines for details.

Preoperative bowel preparation

Traditionally, procedures to empty the large bowel before surgery have been a pillar of preoperative preparation for colorectal procedures with the intention of reducing the bacterial load in the colon and hence risk for infectious complications. Traditional per oral, or mechanical bowel preparation, implies intake of large amounts of fluids together with osmotic and laxative agents that induce diarrhoea. The risk of severe fluid shifts is substantial, especially for elderly and frail patients, and the procedure is quite burdensome. Modern guidelines and reviews have failed to identify significant benefits against the unwanted consequences and have largely advised against it. ^{, , ,} Bowel preparation has, however, received some renewed interest in combination with repeated doses of per oral antibiotics aiming at a more complete decontamination of the large bowel. Recent data indicate that such a combination lowers complication rates in colorectal surgery. A recent meta-analysis reported benefit of oral antibiotics in combination with bowel preparation compared with bowel preparation alone but no benefit of using bowel preparation with antibiotics compared with antibiotics alone, although randomised prospective data were lacking for this comparison. The most recent ERAS guidelines only recommend bowel preparation for selected rectal surgery.

Mechanical preparation (with or without decontaminating antibiotics) or enemas will be necessary in selected colorectal operations. Identifying small and ill-defined lesions during surgery might require careful palpation or intraoperative colonoscopy, both requiring an empty bowel. Furthermore, the use of diverting ileostomies to protect an ultra-low rectal anastomosis is meaningless if the colon is not emptied preoperatively.