5 Preoperative and Postoperative Management of Colorectal Surgery Patients
Abstract
The perioperative management of colorectal surgery patients has changed dramatically in recent years. Efforts toward cost reduction, reducing or eliminating hospital stays, and the increasing use of evidence-based practices have all had an influence. The experience gained from minimally invasive procedures has been transitioned to other patients. Many of these practices have been grouped into Enhanced Recovery After Surgery (ERAS) protocols or care paths. As these practices can be applied in almost all patients, Care Paths seems a better term. Initially, a host of activities were grouped and used with good overall results. Specific components of these protocols are only now being subjected to prospective evaluation. Until such evidence is available, it is difficult to know the true value of each component. Perioperative management is arbitrarily divided into three phases: preoperative, intraoperative, and postoperative.
5.1 General Consideration
The perioperative management of colorectal surgery patients has changed dramatically in recent years. Efforts toward cost reduction, reducing or eliminating hospital stays, and the increasing use of evidence-based practices have all had an influence. In addition, the experience gained from minimally invasive procedures has been transitioned to other patients. Many of these practices have been grouped into Enhanced Recovery After Surgery (ERAS) protocols or care paths. As these practices can be applied in almost all patients, Care Paths seems a better term. Initially, a host of activities were grouped and used with good overall results. Specific components of these protocols have only recently been subject to prospective evaluation. Until such evidence is available, it is difficult to know the true value of each component. Perioperative management is arbitrarily divided into three phases: preoperative, intraoperative, and postoperative. However, some components such as pain management occur in several phases. Important components of each phase are listed in ▶ Table 5.1. An additional discussion of ambulatory anorectal procedures is presented in Chapter 6.
5.2 Preoperative
5.2.1 Patient Education
The patient undergoing an elective colorectal procedure should be given general information regarding their care path, which includes preoperative preparation, in-hospital stay, postoperative period at home, and overall recovery time. This quantity of information may challenge patients’ memories. Best practice is to provide the patient with a handout that summarizes this information.
At the outset, the surgeon should discuss the goals of the proposed intervention. The type of incision, the extent of the wounds to be created, and the anatomy involved should be outlined in addition to various aspects of normal wound healing. Where appropriate, the possibility of a minimally invasive laparoscopic approach and the possibility of intraoperative decision making should be mentioned. The surgeon should also be willing to discuss potential complications. The patient should be afforded the opportunity to ask questions regarding potential risks of the operation, the expected outcome, and any alternative therapy. A discussion of postoperative pain will reassure the patient that the presence of some pain is by itself not an indication that something has gone wrong. At the same time, the patient should be reassured that every effort will be made to minimize their pain with appropriate use of analgesics and that considerate and empathetic nursing care will be offered. Realistic expectations should be given regarding the functional results after “reconstructive” colorectal operations, such as ileoanal procedures, coloanal anastomoses, and anal sphincter repair. If there is a possibility of an ostomy, involvement of a wound and ostomy care nurse is extremely helpful (see Chapter 30).
The patient should be reassured that all measures will be taken to bring about an uneventful postoperative course. At the same time, the patient’s need to cooperate with postoperative care, especially with regard to pulmonary care and ambulation, must be stressed. Finally, all aspects of daily activities pertinent to recovery should be discussed.
5.2.2 Assessment and Optimization of Operative Risk
Recommendations for elective colorectal surgery are based on an appropriate clinical history, physical examination, and diagnostic evaluation. Before any elective colorectal operation, the patient should be assessed and prepared carefully. Special attention should be given to previous exposure to anesthetic agents and medication and to allergies, personal habits (alcohol and drug abuse), and concurrent systemic illness. Since abnormalities in systemic functions may affect the uptake and action as well as the distribution and elimination of anesthetic drugs, the patient should be in the best possible state of fitness consistent with his systemic disease. Operative risk is assessed in the following areas: cardiovascular status, pulmonary function, renal status, hepatic function, hematologic status, nutritional status, obesity, age, and psychological status.
Cardiovascular Status
Patients with a history of myocardial infarction are prone to experience another infarction during or following subsequent operations. The incidence of perioperative myocardial infarction was reviewed by Roizen and Fleisher, 1 who reported the overall reinfarction rate ranged from 1.9 to 15.9%, mostly in the 7 to 9% range, with mortality ranging from 1.1 to 5.4%, mostly in the 3 to 4% range. In the first 3 months following a myocardial infarction, the numbers are much higher with reported reinfarction rates ranging from 0 to 86%, mostly in the 20 to 40% range, with mortality ranging from 0 to 86%, mostly in the 23 to 38% range. With time, the numbers improve so that at 4 to 6 months following myocardial infarction, reinfarction rates range from 0 to 26%, mostly in the 6 to 16% range, and the corresponding mortality rates range from 0 to 5.9%. After 6 months, reinfarction and mortality rates continue to decrease. Since postoperative myocardial infarction is associated with a high mortality rate, it is best to schedule an elective operation 6 months or longer after a previous infarction.
Several drugs used in the treatment of cardiovascular disorders may interfere with anesthesia. For example, diuretics used in the treatment of hypertension can cause hypokalemia. As a result, the action of nondepolarizing muscle relaxants is prolonged and the heart is more irritable. Therefore, when possible, serum potassium concentrations below 3 mEq/L should be corrected before operation. Interaction between β-adrenergic antagonists and anesthetic drugs can result in bradycardia, hypotension, and congestive heart failure. 2 In preparing patients with hypertension, associated organic dysfunctions such as nephropathy and heart failure should be brought under control. If blood pressure is optimal, patient medication can be continued until the time of the operation because circulatory complications due to interaction between antihypertensive drugs and anesthetic agents are now rare.
Review of the patient’s cardiovascular status is especially important when a laparoscopic colorectal procedure is considered, since the maintenance of increased intra-abdominal pressure during prolonged periods of time is not without adverse hemodynamic effects. The extent of the cardiovascular changes depends on several factors such as the level of the insufflation pressure and the volume of carbon dioxide absorbed. Usually, cardiac index and central venous blood pressure remain relatively unchanged. 3 The increased intra-abdominal pressure, however, leads to splanchnic vasoconstriction and a considerable reduction in inferior vena cava, renal, and portal vein blood flow. Because of these changes, the venous return to the heart decreases, which finally results in reduction in stroke volume. 4 The heart rate will rise to compensate for this reduction in stroke volume. At higher-than-normal insufflation pressures, the cardiac output will decline because of failure of this compensation mechanism. The rise in abdominal venous pressure results in a significant increase in systemic vascular resistance and mean arterial blood pressure. 5
Pulmonary Function
The pulmonary function of patients with chronic obstructive lung disease may deteriorate further as a result of ventilatory depression and ventilation–perfusion disturbances occurring during anesthesia. Moreover, postoperative hypoventilation due to residual anesthetic effects and the recumbency and diminished breathing resulting from a painful operative wound may result in pulmonary complications such as retention of secretions, atelectasis, and pulmonary infection. Patients with significant chronic obstructive lung disease might benefit from admission for pulmonary preparation in advance of the operation. Preoperative examination of these patients might include obtaining chest radiographs, arterial blood gas measurements, and pulmonary function tests. Breathing exercises, postural drainage, inhalation therapy with a mucolytic agent or bronchodilator, and administration of corticosteroids may be helpful in improving respiratory function.
Patients with chronic respiratory disease are also at risk during laparoscopic colorectal surgery. The pneumoperitoneum pushes the diaphragm upward and leads to a reduction in pulmonary function. This situation is aggravated when the Trendelenburg position is used. The physiologic dead space will increase and a ventilation–perfusion mismatch will occur. 6 During insufflation with carbon dioxide, the arterial partial pressure of carbon dioxide (PaCO2) rises with a resultant respiratory acidosis. The decrease in pH can be compensated by increasing the ventilation rate. A rise in PaCO2, however, may occur in patients with chronic respiratory disease despite an increase in ventilation, causing a reduction in stroke volume and cardiac arrhythmia. 7 Finally, the patient’s smoking status and history should be documented, and smokers are advised to quit and offered cessation material and programs.
Renal Status
Patients with renal insufficiency are prone to sustain intraoperative and postoperative complications, especially if the renal disorder is associated with hypertension, severe anemia, and electrolyte disturbances. Fortunately, many affected patients tolerate chronic anemia of renal origin relatively well. The introduction and clinical use of erythropoietin has facilitated a more effective treatment of this type of anemia. Therefore, in this group of patients, anemia is not a contraindication to anesthesia and operation. In patients with hyperkalemia, the administration of succinylcholine may result in a further increase in serum potassium concentration. Anesthetic drugs, which are entirely dependent on the kidney for elimination, and nephrotoxic agents are contraindicated in patients with chronic renal insufficiency. Dialysis patients may need to be scheduled the day after their outpatient dialysis, with subsequent treatments performed while an inpatient. Obviously, nephrotoxic drugs (e.g., antibiotics) should be used with increased caution in these patients.
Hepatic Function
Although intravenous (IV) anesthetics and narcotic analgesics are largely eliminated by the liver, the detoxification and excretion of these agents is still adequate in most patients with liver disease, unless liver damage is severe. Special attention should be given to biochemical abnormalities such as hyperbilirubinemia, hypoalbuminemia, and elevated levels of liver enzymes and ammonia. The hypoalbuminemia and the reversed albumin/globulin ratio in liver disease are associated with altered sensitivity to drugs bound to albumin and to globulin. Attention should be directed to the correction of electrolyte disturbances such as dilutional hyponatremia in patients with ascites and hypokalemia due to excessive urinary loss resulting from secondary aldosteronism. In many patients, chronic liver disease is associated with anemia that is due to hemolysis or blood loss from esophageal varices. Thrombocytopenia caused by hypersplenism secondary to portal hypertension may occur in addition to decreased levels of clotting factors II, V, VII, IX, and X. Both abnormalities result in a coagulopathy, which should be corrected by platelet transfusion and administration of fresh frozen plasma. Finally, it should be noted that potentially hepatotoxic agents such as halothane are best avoided.
Hematologic Status
Patients with a low hemoglobin concentration have a decreased oxygen transport capacity. To maintain adequate oxygen delivery, cardiac output is increased in patients with anemia. However, many anemic patients tolerate an operation quite well, unless they present with a concurrent systemic disorder. Furthermore, in many patients admitted for a colorectal operation, a low hemoglobin concentration may be the manifestation of the underlying disease itself, and the proposed intervention may be curative. Although it has been advocated to correct anemia before operation in patients with a hemoglobin concentration below 10 g, many patients with lower values will tolerate operation. Although arbitrary, surgically acceptable ranges for hematocrit are 29 to 57% for men and 27 to 54% for women, and for white blood counts 2,400 to 16,000/mm3 for both men and women. 8
Obesity
Obesity may be associated with endocrine abnormalities, hypertension, heart failure, a smaller-than-normal functional residual capacity, and other complications. Therefore, for markedly obese patients, arterial blood gas and pulmonary function studies and examination for endocrine dysfunction should be part of the preoperative evaluation. Because the obese patient is at increased risk for postoperative complications such as deep vein thrombosis (DVT), pulmonary embolism, and respiratory failure, adequate preoperative and postoperative measures are necessary to minimize these complications. Such measures are effective only in patients who are willing to cooperate, and therefore the potential complications and the necessity to cooperate should be explained to patients prior to operation.
Age
In assessing operative risk, age is another aspect that needs to be taken into account since an increasing number of older patients are requiring major operations. On admission, older patients frequently present with concurrent systemic disorders and inadequate nutrition. As already mentioned, both factors have a negative impact on intraoperative and postoperative morbidity and mortality. Age alone, however, is not a contraindication to operation. Nevertheless, in an older patient with less than optimal fitness, the surgeon may, for example, modify a recommendation for an abdominoperineal resection and opt for a local procedure. With greater age, for example, “reconstructive” procedures such as ileoanal and coloanal anastomoses are relatively contraindicated because both procedures are associated with a functional outcome that is not as good in older patients compared to younger ones.
Physiologic Status
Most patients who have had an operation recommended to them will become anxious. Sometimes, the degree of anxiety will be out of all proportion to the magnitude of the proposed operation. For example, a patient may be offered an anal operation when he or she expects a simple pill or cream to solve the problem. Alternatively, the patient may be seeking help for hemorrhoids and, after examination, learn that the problem is a carcinoma of the rectum for which a proctectomy is being recommended. Clearly, a patient in the latter situation requires considerable reassurance about the change in lifestyle that a stoma may create, along with potential complications such as impotence. Explanation of reasonable expectations from the operation, such as duration of hospitalization and estimated time off from work, as well as reassurance that the patient can return to his former type of work, may do much to calm the patient confronted with this totally unexpected diagnosis.
Nutritional Assessment and Optimization
A patient’s nutritional status has significant influence on postoperative morbidity. 9 In addition, malnutrition is common, with reported rates up to 50% in certain populations of hospitalized patients. 10 Nutritional assessment identifies patients at risk and starts with a history of nutritional intake and weight status. Moderate or severe malnutrition is associated with body weight loss > 10% within 6 months of presentation and a body mass index (BMI) under 18.5 to 22 kg/m2. Physical examination in patients with fat or muscle wasting identifies a low triceps skinfold thickness and a decreased midarm muscle circumference. Other criteria include biochemical parameters such as anemia, low serum albumin level (< 35 g/L), low prealbumin, low serum transferrin level, and deficiencies of vitamins, minerals, and trace elements.
Nutritional support may be indicated for malnourished patients requiring surgical intervention, or for healthy patients undergoing major surgery with an anticipated lengthy recovery time to return of normal gastrointestinal function; however, it is unclear when it is appropriate to intervene. Several studies have demonstrated that 7 to 10 days of preoperative parenteral nutrition improves postoperative outcome in patients with severe undernutrition who cannot be adequately orally or enterally fed. Conversely, its use in well-nourished or mildly undernourished patients is associated either with no benefit or with increased morbidity. 10 , 11 Postoperative parenteral nutrition is recommended in patients who cannot meet their caloric requirements within 7 to 10 days orally or enterally. In patients who require postoperative artificial nutrition, enteral feeding or a combination of enteral and supplementary parenteral feeding is the first choice.
A major consideration when administering fat and carbohydrates in parenteral nutrition is not to overfeed the patient. The commonly used formula of 25 kcal/kg ideal body weight furnishes an approximate estimate of daily energy expenditure and requirements. Under conditions of severe stress, requirements may approach 30 kcal/kg ideal body weights. In those patients who are unable to be fed via the enteral route after surgery, and in whom total or near-total parenteral nutrition is required, a full range of vitamins and trace elements should be supplemented on a daily basis.
A newer aspect of enteral nutrition is immunonutrition (IN) supplements, which may reduce postoperative complications. Braga et al reported that preoperative oral arginine and n-fatty acids improve the immunometabolic response and decrease the infection rate from 32 to 12%. 12 Postoperative supplementation has not shown additional benefits. Many studies included pre- and postoperative regimens and have utilized inconsistent controls. A recent review and meta-analysis reviewed 561 patients in eight randomized controlled trials (RCT) of preoperative IN versus standard oral nutritional supplements (ONS) and 895 patients in nine RCT of IN vs no supplements. 13 There was no difference between IN and ONS, but IN was associated with decreased infectious complications when compared to no supplements.
Several preoperative aspects have been combined into the Strong for Surgery program. 14 This program, initiated in Washington state, brings a presurgery checklist to doctor’s offices to help with education, communication, and standardization of best practices. The program currently focuses on four areas: nutrition, glycemic control, smoking cessation, and medications.
For nutritional screening, four questions are asked: Is the patient’s BMI less than 19? Has the patient had intentional weight loss of over 8 pounds in the last 3 months? Has the patient had a poor appetite—eating less than half or fewer than two meals per day? Is the patient unable to take food orally? If any of these questions are yes, the patient may be referred for evaluation by a dietician or considered for nutritional therapy. A serum albumin is obtained for risk stratification and patients having complex surgery are considered for evidence-based immune modulating supplements.
For blood sugar control, patients with diabetes, age > 45, or BMI > 30 have a fasting blood sugar drawn the morning of surgery. If the glucose level is > 200, then an insulin drip is suggested during the case. Diabetic patients also have a hemoglobin A 1C drawn. If that level is greater than 7% or any finger stick was > 200 in the last 2 weeks, the patients are referred for better diabetic management.
Medications
Medications such as warfarin, clopidogrel, and acetylsalycilic acid are documented with special attention to patients with bleeding risks, beta blockers, and problematic herbal medications, including Echinacea, garlic, ginkgo, ginseng, kava, saw palmetto, St. John’s wort, and valerian.
Laboratory Tests
Screening laboratory studies should be considered before a major surgical procedure. In the past, multiple studies were routinely ordered. Recent critical evaluation of this policy has resulted in significantly fewer studies being performed. Unneeded tests result in unnecessary cost and morbidity. Many of these result from the workup suggested by an abnormal value obtained on “screening tests.” Currently, in the absence of symptoms or disease processes that require evaluation, the studies listed in ▶ Table 5.2 are recommended.
Age (y) | Men | Women |
< 40 | No laboratory tests required | Hemoglobin and hematocrit |
> 40 | ECG | ECG |
Abbreviation: ECG, electrocardiogram. | ||
Chest X-Rays
Routine chest radiography obtained on admission to hospital or in the preoperative setting was a common practice. However, significant evidence and national guidelines argue against such a policy. 15 In 2005, a meta-analysis of manuscripts published between 1966 and 2004 addressed the value of screening preoperative chest radiographs. 16 In this analysis, the diagnostic yield of the preoperative chest radiograph was found to increase with age. However, most of the abnormalities consisted of chronic disorders such as cardiomegaly and chronic obstructive pulmonary disease, which were already identified clinically. The proportion of patients who had a change in management was low (10% of investigated patients). Postoperative pulmonary complications were similar between patients who had preoperative chest radiographs (12.8%) and those who did not (16%). The authors concluded that preoperative screening chest radiographs did not decrease morbidity and mortality. Preoperative chest radiographs should not be performed on patients younger than 70 years and without risk factors. For patients older than 70 years, there is insufficient evidence against performance of routine chest radiographs. Routine preoperative and admission chest radiographs are not recommended except when acute cardiopulmonary disease is suspected on the basis of history and physical examination or there is a history of stable chronic cardiopulmonary disease in an elderly patient (older than 70 years) without a recent chest radiograph within the past 6 months.
5.3 Colorectal Operations
5.3.1 Preoperative Preparation Mechanical Bowel Cleansing
Colorectal operations are associated with a high potential for septic complications that most commonly manifest as surgical site infections (SSIs), wound infections, or as intra-abdominal sepsis. Endogenous bacterial contamination is the most important factor in the development of postoperative wound infection after elective colorectal procedures. However, exogenous contamination and patient-related factors such as age, nutritional status, and other disorders also can contribute to the development of wound infection.
Intra-abdominal sepsis after a colorectal operation is most commonly due to anastomotic dehiscence. Uneventful anastomotic healing depends on many variables, such as the skill of the surgeon and the use of excellent operative techniques. The method by which the anastomosis is made (staples, suture with one vs. two layers), the use or nonuse of drains, the construction of a defunctioning stoma, and the use of peritoneal lavage are other factors that may influence the outcome.
It is generally agreed that antimicrobial preparation is required in order to reduce the incidence of septic complications after elective colorectal surgery. Since many surgeons believed that fecal loading interfered with healing of colonic anastomoses, mechanical bowel preparation (MBP) was a traditional ritual. Proponents of mechanical cleansing justify their practice by referring to a paper published by Irvin and Goligher in 1973. 17 Based on their retrospective study, these authors concluded that poor MBP is associated with a significantly higher incidence of anastomotic dehiscence. They assumed that mechanical cleansing minimizes the risk of fecal impaction at the anastomotic site, thereby reducing undue tension and local ischemia at the suture line. An early randomized clinical trial questioned this view and concluded that vigorous MBP was not necessary. 18 In 1987, Irving and Scrimgeour also questioned the efficacy of mechanical bowel cleansing. 19 , 20 They argued that preoperative bowel cleansing is time-consuming, expensive, unpleasant for the patient, and even dangerous on occasion. More recent concerns involve the fact that an empty colon is easier to manipulate during laparoscopic surgery and a clean colon is helpful if a surgeon needs to palpate a small lesion or use intraoperative colonoscopy.
While many surgeons continue to routinely use MBP for patients undergoing elective colorectal surgeries, some reports suggest that this practice may be abandoned for many procedures and patients. Both clinical trials and retrospective reviews have found a trend toward increased infectious complications in patients who underwent MBP when compared to those who did not. 21 , 22 There have also been reports of earlier return of bowel function and shorter hospital stays among patients who did not have MBP prior to surgery. 21 , 23 , 24 , 25 The most recent large, multicenter trial, however, found that there was no difference between MBP and no-MBP groups in rate of anastomotic leak or severity of infectious complications. 26 ▶ Table 5.3 summarizes the randomized clinical trials on the MBP versus no-MBP issue. 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 A 2011 Cochrane review on MBP in elective colorectal procedures (18 randomized trials with 5,805 patients) did not detect any differences in rates of anastomotic leak or wound infections following colorectal procedures. 40 Based on these conclusions, some experts and national groups had called for the omission of MBP prior to elective colorectal procedures. 41 , 42
There may be exceptions to this recommendation. In cases where a colonoscopy will be performed immediately before the resection, a bowel preparation may still be warranted. This is particularly true in patients with small (< 2 cm) and nonpalpable tumors that may need to be located intraoperatively with a scope. These patients were frequently excluded from trials and therefore conclusions cannot be drawn on the safety of abandoning MBP in these circumstances. 20 , 43
Despite the numerous reports supporting the safety of colorectal procedures without MBP, physicians around the world have been slow to abandon the practice. In a 2002 survey of surgeons in the United States, 99% reported routinely prescribing an MBP prior to colorectal surgery, with 47% using oral sodium phosphate and 32% oral polyethylene glycol solution. 20 A study of almost 300 hospitals in Europe and the United States also found that 96% of patients admitted for a colorectal procedure underwent preoperative MBP. 44 Recent reports from Switzerland and New Zealand are more in line with the recommendations to abandon MBP, with less than half of physicians reporting MBP use in colon procedures. However, even in these countries, MBP use is common during anorectal procedures (60–80%). 42 , 45 Of note, more recent survey studies have found that younger physicians, board-certified colorectal surgeons, and high volume of colorectal surgeons are more likely to have abandoned the practice of MBP prior to elective colorectal procedures. 45 , 46 However, this trend toward abandoning mechanical preparation has been reconsidered in light of several large database studies that have looked at mechanical preparation used with oral antibiotic preparations. This experience is discussed in greater detail in the antibiotic preparation section. In addition, few of the studies looking at MBP for surgery have focused on rectal surgery (e.g., low anterior resections), and most did not evaluate the role of oral antibiotics. 47 Although no significant effect was found, it has been suggested that MBP could be used selectively in rectal surgery below the peritoneal verge in which bowel continuity is restored.
If a mechanical prep is used, it may be a variation of those discussed in Chapter 4. None of the current commercially available colon cleansing preparations has received Federal Drug Administration approval as a preoperative preparation. The author currently uses a limited, low-volume mechanical preparation in most patients: clear liquids the day prior to surgery and two doses (17 g) of polyethylene glycol 3350 (MiraLax) the afternoon prior to surgery. Patients undergoing distal left colon or rectal procedures or those who may need intraoperative colonoscopy receive a polyethylene glycol 3350 preparation (see Box 5.1).
Bowel cleansing preparation
On the day before the procedure, the patient is instructed as follows:
Clear liquids
0900: take 10–20 mg bisacodyl (Dulcolax)
1300: take 1 g of neomycin and 250 mg of metronidazole
1400: take 1 g of neomycin and 250 mg of metronidazole
1600: 240 mL (8 oz) clear liquids
2200: take 1 g of neomycin and 250 mg of metronidazole
Drink plenty of additional clear liquids all day
Nothing by mouth at least 4 h prior to the procedure
Antibiotic Bowel Preparation
The aim of antibiotic prophylaxis is to facilitate the function of the host immune defense system by decreasing or suppressing bacterial growth at the surgical site. 47 The surgical opening of the large bowel causes contamination of the surgical field by endogenous bacteria, so patients undergoing elective colon and rectal surgery are at a high risk of postoperative wound infection. Without antibiotic prophylaxis, SSI after colon and rectal surgery can be as high as 40%. 48 This percentage decreases to approximately 11% with the use of prophylactic antibiotics. 49
In response to the health and financial issues associated with SSIs, the Centers for Disease Control and Prevention (CDC), the Centers for Medicare and Medicaid Services (CMS), and representatives from other established health care organizations are working together on the Surgical Care Improvement Project (SCIP) to reduce surgical morbidity and mortality by targeting several components of surgical care including antibiotic prophylaxis. 50 , 51 SCIP has an infection prevention component for elective surgical procedures, which covers the administration of antibiotics within 1 hour before the surgical incision, appropriate antibiotic selection, and the discontinuation of antibiotics within 24 hours following the surgery end time. Based on these principles, hospitals and physicians are monitoring and implementing adherence with these recommendations. Unfortunately, adoption of these processes has not uniformly resulted in reduced infections. 52
An ideal antibiotic regimen used for prophylaxis during elective colon and rectal surgery should provide broad suppression of fecal flora with activity against aerobic and anaerobic microorganisms. It should be cost effective, provide minimal toxicity, and avoid the emergence of resistant organisms. Furthermore, the choice of antibiotics to be used for prophylaxis should take into account both the microorganisms usually found in the surgical suite and hospital-specific microbiologic epidemiology. Currently, the recommended antibiotic regimen for elective colon and rectal surgery includes an oral or parenteral antimicrobial, or a combination of both. The regimen should include coverage against enteric gram-negative bacilli, anaerobes, and enterococci. The SCIP issued guidelines for the use of prophylactic antibiotics in colorectal surgery. 53 , 54 Cefoxitin (a second-generation cephalosporin) is recommended as the parenteral prophylactic antibiotic of choice; however, the combination of cefazolin and metronidazole can be used as a cost-effective alternative. In cases where gram-negative bacilli have become resistant to cefoxitin, reasonable alternatives include cefazolin plus metronidazole or monotherapy with ampicillin-sulbactam. In patients with confirmed allergies or adverse reactions to beta-lactams, use of clindamycin with gentamicin, aztreonam, or ciprofloxacin, or metronidazole with gentamicin or ciprofloxacin is recommended. A single dose of ertapenem is acceptable for colon and rectal surgery. However, its use has been discouraged, since its widespread use may result in increased rates of resistance. 53
A systematic review of RCTs to evaluate the efficacy of antimicrobial prophylaxis and different regimens in colon and rectal surgery was conducted in 1998. 49 It concluded that the use of prophylactic antibiotics is efficacious in the prevention of SSIs in colon and rectal surgery. With the exception of a few inadequate regimens, there is no significant difference in the rate of SSIs between the regimens studied. Moreover, the use of a multiple-dose regimen may be unnecessary for the prevention of SSIs since single-dose regimens have been demonstrated to be as efficacious as multiple dosing, and may be associated with less toxicity, fewer adverse effects, less risk of developing bacterial resistance, and lower costs. Similarly, no convincing evidence supported the idea that the new-generation cephalosporins were more efficacious than first-generation cephalosporins in preventing SSIs in colon and rectal surgery. In 2009, the same group published a systematic Cochrane review that included 182 trials (30,880 participants). 54 The results were similar to the 1998 study in regard to the fact that no statistically significant differences were shown when comparing short- and long-term duration of prophylaxis or single dose versus multiple dose antibiotics. Statistically significant improvements in the rate of SSIs were noted with the use of combined oral and IV antibiotic prophylaxis when compared to IV alone or oral alone. It concluded that antibiotics covering aerobic and anaerobic bacteria should be delivered orally and intravenously prior to colon and rectal surgery with the resultant risk reduction of SSIs by at least 75%.
The most recent questionnaire regarding the use of prophylactic antibiotics before colon and rectal surgery showed that the use of oral antibiotic prophylaxis was still practiced by 75% of surgeons. IV antibiotic prophylaxis was almost invariably used (98% of the respondents). 20
Prophylactic antibiotics should be administered within 60 minutes of incision to ensure adequate drug tissue levels at the time of the initial incision. If vancomycin or a fluoroquinolone is used, they should be administered within 120 minutes before incision. This timing of administration also reduces the likelihood of antibiotic-associated reactions during induction of anesthesia. 51 , 54 , 55 , 56
A 2007 survey regarding the use of prophylactic antibiotics showed that 75% of colorectal surgeons used oral antibiotics and 98% used IV antibiotics. 55 In regard to redosing of prophylactic antibiotics during surgery, for procedures lasting less than 4 hours, a single dose of IV antibiotics is appropriate. 53 For procedures lasting more than 4 hours or in the setting of major blood loss, repeating dosing is indicated every one to two half-lives of the drug in patients with normal renal function. This recommendation is supported by a retrospective study in 1,548 patients who underwent cardiac surgery lasting more than 240 minutes after preoperative administration of cefazolin. Intraoperative redosing of cefazolin was associated with a 16% reduction in the overall risk for SSI after cardiac surgery, including procedures lasting less than 240 minutes. 57 There has been no evidence that a continuous administration of antibiotics for more than 24 hours after elective colon and rectal surgery decreases the risk of wound infection and that extended dosing may increase the risk of resistant organisms and development of Clostridium difficile colitis. 53 , 54 , 58
Three recent studies have provided insight into the role of MBPs combined with preoperative oral antibiotics. A review of 499 patients from the 2012 Colectomy-Targeted American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) who underwent elective colorectal resections found that patients who received preparation with mechanical cleansing and oral antibiotics had a significantly lower incidence of incisional SSIs, anastomotic leakage, and hospital readmission than patients who received no preparation. 59 A second analysis of 5,021 colon cancer patients from the NSQIP database who underwent scheduled colon resections during 2012–2013 found that solitary MBP and solitary oral bowel preparation had no significant effects on major postoperative complications. However, a combination of mechanical and oral antibiotic preparations showed significant decrease in postoperative morbidity. 60 Finally, a meta-analysis reviewed seven RCTs consisting of 1,769 patients undergoing elective colorectal surgery. 61 Patients who received oral systemic antibiotics and MBP had significantly reduced incisional SSIs compared to patients receiving systemic antibiotics and mechanical preparation (4.6 vs. 12.1%, p < 0.00001). Organ/space SSIs were not significantly different (4.0 vs. 4.8%, p = 0/56). 62 , 63 , 64
These studies along with the Veterans Affairs Surgical Quality Improvement Program (VASQIP) and Michigan Surgical Quality Collaborative (MSQC) provide clear support for combined administration of mechanical cleansing with oral antibiotic preparation before elective colorectal resections. 64 , 65 In the absence of a randomized trial of oral antibiotics alone compared to oral antibiotics and MBP, the combined regimen should be recommended.
A 2016 email survey of American Society of Colon and Rectal Surgeons found that an MBP was used routinely by 59% and selectively by 36%. 65 Oral antibiotics were used routinely by 48% and selectively by 18%. IV antibiotics were always used by 94% and the remaining 6% used them selectively. Thus, the majority of surgeons responding to this survey continue to use a mechanical preparation along with oral and IV antibiotics. The editors routinely employ both mechanical cathartic and oral antibiotic bowel preparation for elective colorectal operations.
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