What are the necessary steps and considerations for a patient with a history of colon cancer or diverticulitis who is undergoing colon surgery, including evaluation, medication, and post-operative care?

Colon Surgery: Comprehensive Management Protocol

Preoperative Evaluation and Optimization

For patients undergoing colon surgery, whether for cancer or diverticulitis, implement a structured preoperative assessment focusing on cardiovascular risk stratification, nutritional status, and disease-specific factors. 1, 2

Cardiac and Medical Assessment

• Calculate the Revised Cardiac Risk Index (RCRI) to estimate perioperative cardiac risk, particularly in patients over 65 years or with known cardiovascular disease 1, 2
• Document American Society of Anesthesiologists (ASA) classification, which guides anesthetic planning 1
• Optimize cardiovascular medications including continuation of beta-blockers, statins, and antihypertensives 3, 1, 2
• Assess hemodynamic stability using specific criteria: pH >7.2, core temperature >35°C, base excess >-8, absence of coagulopathy, and no signs of sepsis 1

Nutritional and Lifestyle Optimization

• Correct anemia with iron supplementation or transfusion as indicated, as this is common in colorectal cancer patients 3, 1
• Provide preoperative nutritional supplementation for malnourished patients (those with weight loss or low albumin), which reduces infectious complications and anastomotic leaks 3
• Implement smoking cessation programs initiated at least 4 weeks before surgery, which improves surgical outcomes 3, 1
• Advise alcohol abstinence, as hazardous alcohol intake increases postoperative infections, cardiopulmonary complications, and bleeding 3, 1

Disease-Specific Evaluation

For Colon Cancer:

• Perform preoperative ileocolonoscopy and MRI enterography to document extent of disease, amount of inflamed/stenosed bowel, and non-affected bowel 3
• Use CT or ultrasonography to document abscesses and fistulas 3
• Document obstetric history in women, as this affects surgical planning 3
• Note that obesity (BMI ≥30) correlates with increased surgical complications 3

For Diverticulitis:

• Obtain thorough medical and close contact history 3
• Perform chest x-ray and abdominal CT scan 3
• For complicated diverticulitis (Hinchey class 1 and 2), maximize conservative approach with IV antibiotics and percutaneous drainage before considering surgery 3
• Reserve surgery for purulent or fecal peritonitis (Hinchey class 3 and 4) 3

Preoperative Counseling

• Conduct dedicated preoperative counseling sessions with surgeon, anesthetist, and nurse 3
• For patients requiring stoma, arrange preadmission enterostomal therapy nursing visit to prepare them and reduce postoperative length of stay 3, 4
• Provide detailed information about the surgical procedure, expected recovery course, and active patient participation requirements 4

Immediate Preoperative Management

Bowel Preparation and Fasting

• Avoid routine mechanical bowel preparation for colonic surgery, as it does not improve outcomes and causes dehydration and electrolyte disturbances 3, 2, 4
• Allow clear fluids up to 2 hours before anesthesia 3, 2, 4
• Allow light meals up to 6 hours before anesthesia 2, 4
• Administer oral carbohydrate-rich drinks (400ml with 50g CHO) 2 hours before surgery to reduce insulin resistance and catabolism 2, 4

Prophylaxis

• Administer single-dose intravenous antibiotic prophylaxis 30-60 minutes before incision, targeting Gram-negative bacilli and anaerobes 1, 4
• Apply well-fitting compression stockings and administer low molecular weight heparin (LMWH) for thromboprophylaxis 3, 1, 2, 4
• For colorectal cancer patients, consider extended thromboprophylaxis for 28 days given increased VTE risk 1
• Avoid long-acting sedative premedications, especially in patients over 60 years, due to increased delirium risk and delayed recovery 1, 2

Intraoperative Management

Surgical Approach

• Utilize laparoscopic approach when feasible to reduce inflammatory response and improve outcomes 2, 4, 5
• For complicated diverticulitis requiring emergency surgery with perforation, prefer open approach in COVID-19 positive patients or when adequate laparoscopic devices are unavailable 3
• For emergency left-sided pathology in unstable patients, Hartmann's procedure remains the procedure of choice 1
• Avoid colorectal anastomosis in suspected or confirmed COVID-19 patients due to high risk of complications 3

Anesthetic Technique

• Implement thoracic epidural analgesia (T7-10) with local anesthetics and low-dose opioids for open procedures 1, 2, 4
• Use short-acting agents: propofol for induction (1-1.5 mg/kg in elderly/ASA III-IV, titrated slowly at 20mg every 10 seconds) 1
• Maintain with sevoflurane or desflurane in oxygen-enriched air, or total intravenous anesthesia (TIVA) if high PONV risk 1

Hemodynamic and Fluid Management

• Implement goal-directed fluid therapy using cardiac output monitoring to optimize hemodynamics and avoid fluid overload 1, 2, 4
• Maintain mean arterial pressure with vasopressors after achieving normovolemia, particularly important with epidural use 1, 2
• Maintain close intraoperative communication between surgeon and anesthesiologist to assess resuscitation effectiveness 1

Temperature and PONV Management

• Maintain normothermia (>36°C) using active warming devices and warmed intravenous fluids 3, 1, 2, 4
• Implement PONV prophylaxis using a multimodal approach in patients with ≥2 risk factors 2, 4

Tubes and Drains

• Remove nasogastric tubes before reversal of anesthesia 2, 4
• Avoid routine drainage of the peritoneal cavity after colonic anastomosis 2, 4

Postoperative Care

Pain Management

• Continue thoracic epidural analgesia for 48-72 hours for open surgery 1, 2, 4
• Implement multimodal analgesia with acetaminophen and NSAIDs to reduce opioid requirements 1, 2, 4

Early Recovery Protocol

• Mobilize patient within 24 hours of surgery 1, 2, 4
• Resume oral diet within 24 hours postoperatively 1, 2, 4
• Remove urinary catheter within 1-2 days 1, 2, 4
• Continue thromboprophylaxis with compression stockings and LMWH 2

Laxative Use

• Encourage laxative use to minimize postoperative ileus in patients with intact colon 3
• Avoid laxatives in patients with end ileostomy or diverting ileostomy 3

Disease-Specific Postoperative Considerations

For Colon Cancer

• Plan follow-up colonoscopy 4-6 weeks after surgery for patients with CT-proven pericolic abscesses treated non-operatively, as 11.4% may have cancer mimicking diverticulitis 3
• Do not perform routine colonoscopy after CT-proven uncomplicated diverticulitis, as the risk of malignancy is only 1.16% 3
• For patients with complicated diverticulitis (abscess), colonoscopy is essential as the cancer risk is significantly elevated 3, 6

For Diverticulitis

• Do not use mesalamine to prevent recurrent diverticulitis, as high-certainty evidence shows no benefit and it causes adverse events including epigastric pain, nausea, diarrhea, and renal/hepatic impairment 3
• Discuss elective surgery for patients with persistent uncomplicated diverticulitis (>3 months) or frequent recurrence (≥3 episodes within 2 years), as recurrence rates are lower after surgery 3
• For complicated diverticulitis, discuss elective surgery after recovery, as it is cost-effective at 5 years and improves quality of life 3

Critical Pitfalls to Avoid

• Failure to maintain close surgeon-anesthesiologist communication can result in inadequate resuscitation assessment and poor treatment decisions 1
• Fluid overload contributes to postoperative ileus; avoid excessive fluid administration 2
• Inadequate temperature monitoring and warming leads to coagulopathy and increased complications 1
• Delaying surgery while waiting for COVID-19 swab results in emergency cases; proceed with appropriate PPE 3
• Performing anastomosis in high-risk situations (COVID-19 positive, hemodynamically unstable, malnourished, or on high-dose steroids/anti-TNF agents); prefer Hartmann's procedure 3, 1
• Routine colonoscopy after uncomplicated diverticulitis wastes resources without clinical benefit 3