The majority of patients undergoing colorectal surgical procedures may be elderly having significant comorbidities. It is important to optimize their condition by treating heart failure, diabetes mellitus, chronic obstructive pulmonary disease and renal disease. A preoperative assessment clinic managed by trained nurses and/or anaesthesiologists help to detect these comorbidities. Depending on the severity, the patients can then be referred to the cardiologists and other physicians for their optimization of their medical comorbidities.

Cardiopulmonary exercise testing, tests of frailty and functional capacity may help to identify patients who may need higher level of care perioperatively. Although pulmonary rehabilitation before lung resection has been proven valuable in certain groups of high-risk patients, studies of prehabilitation, in general, have produced equivocal results to date (Killewich 2006).

It may be speculative to presume that an attempt to improve nutritional status, better use of drugs and use of preoperative and postoperative physiotherapy to improve the grade of frailty would improve outcome at this stage. However, one may suspect that with the help of dietitians, pharmacists and physiotherapists in a multidisciplinary approach, prehabilitation might show benefit in well-defined patient groups. Examples of such patient groups are patients found to have poor anaerobic threshold on cardiopulmonary exercise testing or patients who are positive for being frail.

In our centre, the patients are assessed and started on a prehabilitation program by the physiotherapists with the aim of improving their frailty status. Their family members are also actively involved so that the patients can continue their prescribed exercises back in the community. For those who do not have caregivers at home, they are transferred to a rehabilitation hospital where collaborative rehabilitation plan is drawn out and instituted.

Explicit information regarding various aspects of the preoperative management, intraoperative surgical and anaesthetic procedures and postoperative recovery is given to the patients. This enables better recovery and improved pain relief postoperatively. Being well-informed, knowing what to expect and understanding how they can contribute to their recovery by mobilizing and feeding early appear to reduce the anxiety and stress related to surgery.

Interactive discussions between the patient and nurse facilitator with the aid of an information booklet can help elicit the patient’s expectations and clarify queries about the procedure and recovery process. Patients who may need psychological assessment and therapy, especially those devastated by the diagnosis of a malignancy, can also be referred. Medical social workers can also be engaged to help out those in need of financial and social support.

Bowel preparation causes dehydration and electrolyte imbalances (Holte et al. 2004) which may increase the risk of cardiac arrhythmias and diminished organ perfusion. Well-conducted RCTs have shown that bowel preparation is of no benefit and may even increase the incidence of anastomotic leaks and delay intestinal recovery. It is recommended that it should not be used unless there is a definitive need for it (e.g. intraoperative colonoscopy, total mesorectal excisions or ultra-low rectal tumour resections).

Whether or not bowel preparation is used, the decision should be communicated between the surgical team and anaesthesia team as the subsequent intraoperative electrolyte and fluid management may need to be altered.

It was standard practice to fast patients for more than 6 h before surgery to prevent aspiration of gastric contents but a Cochrane review based on 22 RCTs has shown that it is safe for patients to have clear fluids up to 2 h before induction of anaesthesia. It is also recommended by various national anaesthesia societies that 6 h fasting for solids is adequate (Apfelbaum et al. 1999).

Carbohydrate drinks on the day before surgery and up to 2 h before surgery reduce thirst, provide calories to the patients, and reduce catabolism and the breakdown of body proteins. It has also been shown to reduce postoperative insulin resistance and hyperglycaemia facilitating an anabolic state to benefit from postoperative nutrition, hence allowing accelerated recovery and shorter hospital stay (Noblett et al. 2006).

In most uncomplicated patients, a standard dose of carbohydrate drinks can be given according to protocol. However, certain groups of patients such as those with diabetes mellitus may need a change in the concentration and dose of the carbohydrate drinks to ensure their blood glucose control remains stable. These require specialized expertise from the dietitians and pharmacists.

Both unfractionated heparin and low-molecular-weight heparins are equally effective in preventing deep vein thrombosis, pulmonary embolism and mortality. LMWH is preferred due to its convenient once-a-day dosing and reduced incidence of heparin-induced thrombocytopaenia. In patients who may have epidurals for analgesia, particular attention needs to be given to the timing of the heparin dose. It is advised that the epidural catheter should not be inserted or removed within 12 h of heparin use. In situations where heparin is contraindicated, other forms of prophylaxis such as dextrans, thromboembolism-deterrent stockings and calf compressors should be considered (Koch et al. 1997).

It is recommended that intravenous antibiotics to cover aerobic and anaerobic organisms be given about 60 min before skin incision (Song and Gelnny 1998). There are also some suggestions that antibiotics given closer to the time of the incision may provide adequate protection. A second-generation cephalosporin and metronidazole are adequate. If surgery is prolonged, a second dose of antibiotic should be given.

It may be useful to consult the microbiologist about the specific microbiogram of the institution so that the prophylactic antibiotics may be targeted at the common organisms and their sensitivities.

The use of pre-anaesthetic medication may prolong sedation after surgery; hence they are avoided. Patients who are extremely anxious may have anxiolytics which have short half-life and no active metabolites.

The recommendation is to use short-acting drugs in either total intravenous anaesthetic or inhalational anaesthetic techniques. Drugs which may be suitable are propofol, remifentanil, sevoflurane and desflurane. Morphine and other long-acting opioids may delay recovery of intestinal motility; hence they are better avoided. Mid-thoracic epidurals may offer some advantages especially in open colorectal surgery as it may reduce the amounts of anaesthetic drugs, reduce the stress response, provide better analgesia perioperatively and potentiate immunological functions (Ahlers et al 2008). However, epidural analgesia has not been shown to improve postoperative outcome in laparoscopic surgery.

The role of the anaesthesiologists has evolved to encompass not only intraoperative anaesthetic management but also preoperative and postoperative considerations. The anaesthetic technique should be chosen after communication with the surgeons and patients, keeping in mind their effects on postoperative outcomes. It is more effective if the anaesthetic team begin their point of contact with the patient way before the day of the surgery so that perioperative plans can be suitably discussed.

Some patients may feel postoperative nausea and vomiting (PONV) more stressful than the pain after surgery. The risk factors for PONV are female, nonsmoking status, motion sickness or previous PONV and use of long-acting opioids for pain control (Apfel et al. 2002). Patients who are at risk may be given prophylactic intravenous dexamethasone up to 8 mg, which was also shown to be associated with significantly lower interleukin-6 and interleukin-3 in peritoneal fluid and reduced early postoperative fatigue (Zargar-Shoshtari et al. 2009). Serotonin receptor antagonists such as ondansetron are better given near the end of surgery. Patients who are at high risk of PONV are recommended to have total intravenous anaesthesia with propofol and remifentanil. A small dose of droperidol and metoclopramide may be given in addition to the above-mentioned.

Traditionally the amount of intravenous fluids given perioperatively was much more than that of the actual loss. Patients appeared to gain about 3–4 kg in weight in the perioperative period. This approach can cause oedema affecting tissue oxygenation, delay the return of gastrointestinal function, impair wound and anastomotic healing and eventually lead to prolonged hospital stay (Brandstrup et al. 2003).

Goal-directed haemodynamic management using volume-, flow- or pressure-based goals has been used. It was thought that avoidance of hypovolaemia and maximum oxygen delivery to tissues and organs would be achieved with this approach. Fluids were given to achieve near maximal stroke volume by targeting maximal flow using a trans-oesophageal Doppler ultrasound probe. At times the fluid balance was positive with this approach.

Targeting zero fluid balance by calculating amount of fluid lost and replacing with the same amount of fluid and maintaining body weight is the restricted approach (Brandstrup et al. 2012). This is based on the hypothesis that excess fluids may cause interstitial oedema leading to cardiac and pulmonary complications and reduce tissue healing. It appears that maintaining adequate blood pressure is equally important as maintaining cardiac output to reduce the incidence of anastomotic leak. If the patient’s blood pressure is low due to epidural analgesia, it is better treated with vasopressors instead of the traditional approach of fluid loading.

Dehydration can be avoided in the preoperative period by allowing clear oral fluids up to 2 h preoperatively and avoidance of bowel preparation. Postoperative fluid therapy should take into account maintenance requirements, sensible and insensible losses as well as pathophysiological changes causing fluid shift associated with bowel surgery. The best way to limit postoperative fluid intake is to stop intravenous fluids and return to oral fluids at the earliest.

Fluid management in the postoperative period is usually more difficult as fluid status and deficits are difficult to quantify without sophisticated tools like those used intraoperatively. Blood pressure readings and urine output monitoring are often poor surrogate measures of actual tissue perfusion. Often numerous doctors, including surgical team doctors, acute pain service team and junior doctors on duty at night, are involved in the management in the ward. A conscious team effort and awareness about avoiding fluid overload should be emphasized during the ward rounds and training.

By causing smaller area of injury, laparoscopic surgery may be considered to cause less stress response. Meta-analyses confirmed that significant improvements in short term outcomes are achievable by laparoscopic-assisted surgery as a single intervention. However, the advent of laparoscopic surgery and fast-track protocols coincided with each other and hence there is not enough evidence to show that laparoscopic-assisted surgery when compared to open surgery within an enhanced recovery program will shorten recovery time and reduce length of hospital stay (Tjandra and Chan 2006).

Incisions may be vertical, transverse or curved when open surgery is performed. Even though some RCTs suggest transverse or curved incisions lead to less pulmonary complications and pain, others have found no advantages (Grantcharov and Rosenberg 2001). A Cochrane review of RCTs showed that complication rates and recovery times were not different from vertical midline incisions. It appears that the size and direction of incisions made by surgeons depend on the anticipated difficulty from factors such as scan findings and previous scars.

Patients who do not have nasogastric tubes for decompression of the stomach appear to have lower incidence of pneumonia, fever and atelectasis. A Cochrane review and meta-analysis confirmed this by finding that patients, whose stomachs were not decompressed, had earlier return of bowel function (Nelson et al. 2007). At times significant amount of air may enter the stomach at induction of anaesthesia prior to intubation, compromising surgical approach. If this happens, the stomach may be decompressed with a nasogastric tube intraoperatively. It is advised that this be removed before emergence from anaesthesia.

Anaesthesia-related factors and heat loss from exposed organs lead to hypothermia during surgery. Postoperative cardiac complications and coagulation abnormalities are aggravated by hypothermia. Hypothermia can also cause systemic changes such as exaggerated stress response and suppression of immune function. It is recommended that the temperature of the patient is maintained above 35 °C by using warmed fluid and external warming.

Drainage of peritoneal cavity was previously considered to be useful in preventing or detecting anastomotic leak early. But a meta-analysis has not shown that this is true. There may be some benefit if peritoneal drainage is performed in patients with very low anterior resections (Karliczek et al. 2006).