8 improved outcomes in colon and rectal surgery a narcotic-sparing role. In a study of over 1,000 patients, the addi- tion of ketorolac to standard intravenous morphine significantly reduced the overall postoperative morphine requirements, and low- ered side effects both directly attributable to the narcotic (mental status, pulmonary) as well as gastrointestinal function (ileus, nau- sea, vomiting).(4) The anti-inflammatory action of these agents, especially when used on a set schedule, may be most beneficial for the pain associated with the musculoskeletal trauma of the incision, allowing a significant reduction in pain without the untoward side effects associated with narcotic use. Pain following anorectal surgery can be quite debilitating and is often cited by patients as a primary deterrent toward undergo- ing needed procedures such as hemorrhoidectomy.(5) In addition to the local trauma associated with resection, pain following anal canal procedures is often attributed to anal sphincter spasm. This, in combination with the constipation and hard stools often asso- ciated with narcotic use, results in additional pain and suffering once return of bowel function commences. As in the laparotomy literature, recent trials have shown a marked decrease in the nar- cotic requirements using ketorolac and other NSAIDs periopera- tively for anorectal surgery.(6) Local anesthesia, which has been commonly employed in the field of anorectal surgery, has recently been expanded to continued use postoperatively following abdominal procedures. As a primary modality during anorectal procedures, it has been shown to be effec- tive and safe, with or without the addition of deep intravenous seda- tion, and provides the additional benefit of less time in the recovery room.(7, 8) As an adjunct following laparotomy, a local anesthetic agent is applied via continuous infusion to the midline wound through a set of subcutaneous catheters placed at the time of surgery. (9) Despite mixed results, some prospective data does demonstrate a decreased narcotic requirement and improved perioperative recov- ery, including earlier ambulation, in the absence of significant overall postoperative pain score differences.(10, 11) As increased experi- ence is gathered using this modality, further data may determine its appropriate place in the analgesia armamentarium. Another method commonly employed is epidural anesthesia, which works through inhibiting ascending neural pathways as well as the sympathetic output from the spinal cord. This dual action provides the beneficial effects of not only improved pain control, but also has been shown to aid with earlier return of bowel function through its sympathectomy. Various agents have been described for use in epidurals, with the mainstays being local anesthetics and narcotics. In a meta-analysis of sixteen randomized controlled tri- als from 1987 to 2005 comparing the use of epidurals to paren- teral controlled analgesia, Marret and colleagues found epidurals were associated with improved analgesia and overall decreased ileus, with only side effects such as pruritis and labile blood pres- sure significantly associated with epidural use.(12) Gendall and colleagues confirmed these findings in a recent review of the lit- erature, again demonstrating that epidural anesthesia improves functional recovery and pain relief, while potentially decreasing pulmonary complications.(13) While the epidural is in place, the anesthesiologist often manages all of the pain medications, per- forming comprehensive pain management. When the epidural is removed, the management returns to the surgeon. The use of anticoagulation for deep venous thrombosis (DVT) prophylaxis and epidural placement/removal must be coordinated between the surgeon and anesthesiologist. Downsides to epidurals have consistently been their potential for increasing urinary retention and hypotension, higher costs, and perhaps decreased patient sat- isfaction, with no change in length of stay.(14) Despite these nega- tive attributes, epidural use for colorectal surgery provides the potential for outcome improvement in analgesia and functional recovery, and is a very useful alternative for pain control following abdominal and large pelvic procedures. Furthermore, gabapentin, a medication that was originally designed for the treatment of epilepsy, has evolved as a treatment for mainly neuropathic pain, and has been studied extensively in both the pre- and postoperative settings. Although the exact mecha- nism of action is unknown, it is believed to act through N-gated calcium channels, and focus has been on both providing improved perioperative analgesia as well as narcotic-reducing effects.(15) Unfortunately, its use as an independent entity has been less effica- cious, and it has not been extensively studied for either colorectal or anorectal surgery.(16) Both it, and a newer analog pregabalin, have been shown to decrease the need for opioids and thus reduce side effects such as nausea, vomiting, and urinary retention in other surgical arenas. While further study awaits recommendations spe- cifically for use in the realm of colon and rectal surgery, these medi- cations, along with standard postoperative regimen of increased oral fluid intake, fiber, stool softeners, sitz baths, and avoidance of constipation all aid in recovery from anorectal surgery. Most importantly, these varying agents all operating through different mechanisms convey the needed concept for the surgeon to use a multimodality approach to ensure successful perioperative pain management. Figure 8.1 Thumbtack occlusion of a bleeding basivertebral vein.  general postoperative complications bleedinG Bleeding complications with any operation can be categorized by many different methods including intraoperative, postopera- tive, anastomotic bleeding, and gastrointestinal bleeding, such as stress-related ulcers. One of the most important factors for the surgeon is to preoperatively assess and determine the risk of bleeding. A thorough history and physical examination with emphasis on a personal or family history of bleeding tendency is crucial to identification and subsequent evaluation of those patients at risk, and should be completed before embarking on surgery. Questions should focus on any predisposition for easy bleeding or bruising, inability to clot even with mild cuts, or his- tory of prior transfusions following surgeries, to identify certain patients that require further evaluation. Preoperative laboratory evaluation should include a complete blood count, coagulation panel (PT, PTT, INR), and platelet count. For those patients at increased risk, a more detailed analysis of platelet and clotting cascade function to include bleeding times, mixing studies, or evaluation by a hematologist may be appropriate. Perioperative bleeding with colorectal surgery depends in many aspects on the surgical procedure performed. Whereas bleeding rates following hemorrhoidectomy range from 2% to 6%, those fol- lowing major abdominal operations such as total mesorectal exci- sion (TME) for rectal cancer have been shown to have much higher blood loss estimates, with transfusion requirements reported in up to 43–73% of patients.(17–20) The most common causes for postoperative hemorrhoidal bleeding are technical failure (failed knot) within the first 24 hours, and infection with erosion at 7 days. Despite this, bleeding following hemorrhoidectomy is often able to be controlled either without surgical intervention or with simple suture ligation in the outpatient setting. In contrast, bleeding following major abdominal or pelvic procedures can mandate return to the operating room with corresponding physiological changes that may lead to cardio- pulmonary complications. Yet, with the emergence of emphasis on decreased mandatory transfusion requirements, and techno- logical advancements such as improved minimally invasive tech- niques, transfusion rates are decreasing and blood loss has also decreased. In a study of 147 patients in a case-matched compara- tive analysis between open and laparoscopic colectomies, Kiran and colleagues found that both estimated blood loss and peri- operative transfusion rates were significantly higher in the open group.(21) Timing of the onset of bleeding also provides some insight as to its etiology. Early postoperative bleeding is typically from a technical error at the time of operation.(22) Late bleed- ing, which tends to present days to weeks after surgery, (though not outside the realm of technical problems) is more commonly secondary to patient factors such as an underlying bleeding ten- dency, concomitant coagulopathy, or spontaneous rupture or hemorrhage. It is worth noting that the risk of severe bleeding such as after a two or three quadrant hemorrhoidectomy, despite being small (2–6%), can be catastrophic.(5, 19) Therefore, it is imperative that the possibility of bleeding is discussed with all patients preoperatively, no matter how minor of a surgical proce- dure the patient is undergoing. Although uncommon, massive presacral bleeding during pelvic dissection can result in hemodynamic instability and even death. Injury is secondary to dissection outside the avascular plane. Initial management includes packing and leveling the patient on the oper- ating room table, along with continued resuscitation. This is effective for most patients within 20–30 minutes. Multiple other methods have described including electrocautery, suture ligation, sacral thumbtacks (Figure 8-1), muscle fragment welding, placement of tissue expand- ers or cyanoacrylate adhesives, topical hemostatic agents, and endo- scopic tacking devices.(23–28) Although the presacral veins may be injured, continued bleeding nonresponsive to initial management is most commonly from the basivertebral veins through the sacral foramina.(24, 29, 30) When all else fails, pelvic packing, peritoneal closure, warming, and resuscitation in the ICU with return to the operating room 24–48 hours later may be required. Thus, emphasis on proper technique, knowledge of the pertinent anatomy, and com- prehension of options to immediately consider when things do go awry are all important to decrease perioperative bleeding complica- tions and subsequent clinical complications. infection Surgical-Site Infection (SSI) Surgical site infections continue to be a major source of cost and morbidity despite a strong emphasis on proper selection, timing and duration of perioperative antibiotics. Infections can be clas- sified as surgical site infections, general postoperative infections such as pneumonia and urinary tract (which will be covered in separate sections), and infectious processes that deal specifi- cally with the operation itself (i.e., anastomotic leaks, abscesses). Although multiple different patient and surgical factors contrib- ute to the development of postoperative infections, development of any infectious complication results in increased patient suf- fering, length of stay, and delayed recovery. Additionally, hospital costs encompassing antibiotics, interventional procedures, nurs- ing support, and surgical intervention contribute to driving up overall healthcare system costs. In simple terms, our skin and mucosal lining remain the primary defense mechanisms against infectious sources. With surgery, the breach in these protective layers, along with manipu- lation of the bowel and potential spillage of stool from various colorectal procedures lead to increased rate of infections. Those patients with an extensive component of cellulitis, characterized by leukocytic infiltration of the dermis, bacterial presence, and localized inflammatory response, typically require the addition of antibiotics, especially in patients with immunosuppresion, diabe- tes mellitus and the elderly. With the emergence of methicillin- resistant Staphylococcus aureus (MRSA) and other multiresistant bacteria, it is imperative for the surgeon to help control the emer- gence of these more virulent pathogens by avoiding prolonged usage of antibiotics and changing antibiotics once the pathogens are cultured and appropriate sensitivity to antibiotics is known. With such a drastic rise in the incidence of MRSA, some hospitals are performing preadmission screening cultures for this patho- gen. Thus, if there is an emergence of an active MRSA infection in the postoperative period, the patient most likely brought the infection into the hospital with them. Its presence then is not a result of failure of the surgeon or hospital personnel to follow protocol prevention. From a surgical perspective, proper wound  improved outcomes in colon and rectal surgery care, drainage of abscesses, and debridement of any necrotic tis- sue, where appropriate, remain important adjuncts to the medi- cal management of infections. Aspiration and drainage under imaging can often be used to convert an urgent reexploration to either an elective procedure or provide the ability to avoid a reop- eration altogether. In addition to proper surgical technique that avoids con- verting a clean contaminated to a dirty case, identification of at-risk patients can aid in early identification and treatment of infectious complications. In a review of 428 patients specifi- cally undergoing colorectal operations, surgical site infections were independently associated with increased body mass index (BMI) (odds ratio [OR] 1.07), and those in which a revision/ creation/or takedown of a stoma was involved (OR = 2.2).(31) In addition, with the emerging pandemic of obesity through- out the world, increased BMI has been found to be associated with not only higher rate of surgical site infections, but also is an independent predictor of wound dehiscence, herniation, and anastomotic leak.(32) Different methods have been employed to attempt to decrease the incidence of surgical site infections. There is some debate in the literature regarding the duration of antibiotic use for elective colon and rectal surgery. Although preoperative use of intrave- nous antibiotics to ensure adequate tissue concentrations at the time of incision has become standard of care, there is some con- troversy regarding the use of a single dose versus multiple doses. Fujita and colleagues performed a study including almost 400 patients undergoing elective resection of colorectal cancer and found that the three dose regimen of an every 8 hour, second generation cephalosporin (i.e., 24-hour perioperative coverage) significantly decreased the incidence of surgical site infections over a single preoperative dose (4.3% vs. 14.2%, p = 0.009).(33) However, organ or space SSI and other postoperative infectious complications did not differ between the two groups, and has similarly been not significantly different in many other studies. The practice of adding oral antibiotics has similarly contradic- tory evidence, with large prospective randomized trials demon- strating no decrease in infectious complications, while increasing the rates of nausea, pain, and noncompliance.(34, 35) Yet, other authors including a large prospective randomized trial and meta- analysis of 13 studies demonstrated the addition of oral antibiot- ics to systemic antibiotics was associated with a higher rate of prevention of surgical site infections.(36, 37) Proponents cite the ability of the oral antibiotics to decrease the bacterial load in the colon, as well as the marked increase of colonic bacterial isolates from the infected surgical wounds as evidence and ratio- nale for its use. With such varying opinions, it is up to the indi- vidual surgeon to evaluate the literature and determine the best approach as it applies to their patient population. Finally, besides the proper use and timing of preoperative antibiotics, supple- mental postoperative high dose oxygen (80%) has been shown to reduce surgical site infections by approximately 6–40%.(38, 39) Through suggested mechanisms, including more efficient electron- transport chain off-loading and improved neutrophil function, postoperative high-flow oxygen in the immediate recovery period has become part of a standardized postoperative pathway for many institutions. Finally, fewer complications may be associated with maintaining perioperative normothermia in patients undergo- ing colorectal surgery. Employing methods such as preoperative warming with bear-hugger devices, use of warm blankets and fluids, and avoiding prolonged or unnecessary exposure, may all result in less SSI. urinary tract infection and retention Urinary tract infections are the leading cause of nosocomial infections, accounting for ~40% of all infections, of which 80% are associated with transurethral catheter placement.(40) The dilemma remains how to significantly reduce this rate, especially in light of the chronic use of urinary catheters during colorectal procedures. A recent Cochrane review evaluating the use of anti- biotics during short-term catheter use demonstrated there was a paucity of evidence that antibiotic prophylaxis was any better than treating patients when clinically symptomatic. While it did show some weaker evidence that bacteriuria, pyuria, and gram- negative bacteria are all reduced following antibiotic use over 24 hours or until catheter removal, none of these studies specifically focused on the colon and rectal patient. In addition, there was limited data on cost or subsequent development of multiresis- tant organisms, and most patients undergoing colorectal sur- gery receive perioperative antibiotics to cover bowel flora. Thus, caution needs to be taken when determining the applicability of these results to colorectal surgical patients. Following rectal sur- gery, urinary tract infection in part depends on the clinical prac- tice of the surgeon regarding length of time of bladder catheter drainage. In a study comparing catheter removal at 1 and 5 days following rectal resection, Benoist and colleagues found urinary tract infections to be increased in those patients with catheters in for 5 days versus those who removed after 1 day (42% vs. 20%, p < 0.01).(41) Increases in urinary tract infection with prolonged drainage must be balanced with voiding dysfunction with early catheter removal. Unfortunately, urinary retention remains a well-known com- plication of colorectal and anorectal surgery, as well as a result of the spinal anesthesia commonly used during these operations.(42) In the Benoist study, urinary retention was significantly increased in those with the catheter present for only 1 day of postoperative drainage over the 5-day cohort (25% vs. 10%, p < 0.05), especially amongst those with tumors of the low rectum.(41) Following pel- vic surgery, this may be, in part, secondary to third spacing and edema around the urethra following disruption of these tissue planes. Thus, in abdominal surgery, where the dissection does not proceed below the peritoneal reflection, this may lower the rate of dysfunction. The authors concluded that 1 day of drainage is adequate for most patients, although for patients undergoing lower resections, longer periods of drainage may be optimal. Changchien and associates in a review of 2,355 patients with colorectal cancer found urinary retention to be significantly associated with mul- tiple factors to include older age, history of lung disease, rectal cancer, longer operations, and additional pelvic procedures such as hysterectomy or cystectomy.(43) Additionally, male gender, American Society of Anesthesiologists’ (ASA) score of 2 or 3, rectal cancer, use of a pelvic drain, and pelvic infection were indepen- dently associated with prolonged urinary dysfunction, defined as continued problems over one month postoperatively. To lessen  general postoperative complications the higher rates associated with transurethral catheter placement, some authors have also advocated suprapubic catheter drainage. In patients undergoing pelvic surgery, this has been associated with similar voiding dysfunction rates, but fewer infectious complica- tions than the traditional transurethral route.(44, 45) Following anorectal surgery, urinary retention rates have been reported to be up to 50%.(46) Multiple methods that have attempted to decrease this rate have limited perioperative fluid, use of local versus spinal anesthesia, and even use of alpha-adrenergic blockade preemptively.(46) Although the latter did not seem to sig- nificantly affect rates of voiding dysfunction, both fluid restriction and adequate pain control have consistently been shown to have a positive effect at decreasing this difficult problem.(47, 48) Toyonaga and associates, in a prospective study of over 2000, patients found independent predictors significantly associated with the develop- ment of urinary retention following anorectal surgery were female sex, prior urinary difficulties, diabetes mellitus, intraoperative flu- ids over 1 L, and prolonged need for postoperative analgesics.(48) Although urinary retention is known to increase overall length of hospital stay, (42) careful patient education and strict fluid control have allowed most anorectal surgeries to be performed in an ambu- latory setting with a low rate of return for urinary catheterization. (49) Additional use of agents such as NSAIDs and Ketorolac may minimize narcotic use and increase the success rate by avoiding this complication in an outpatient setting.(6) Surgeons therefore need to be in constant communication with their anesthesia counter- parts to discuss excessive fluids and proper analgesia, as many are unaware of the potential downfall of these common practices. atelectasis Prevention Basic principles of airway clearance, avoidance of splinting and alveolar collapse, while preserving functional residual capacity and pulmonary reserve remain important components of proper postoperative pulmonary toilet. As a part of the “5 W’s” of the postoperative fever, “wind” as it relates to atelectasis reminds phy- sicians that optimizing ventilation and oxygenation are keys to successful recovery, and are subsequently passed down to succes- sive generations of training surgeons (as much as absolute truth as ancient lore). The fundamental principle behind avoidance of atelectasis has been shown to be successful in pulmonary processes ranging from cystic fibrosis and acute spinal cord injury to post- operative esophagectomy.(50–52) As such, factors such as head of bed elevation, early ambulation, and the ever-present incentive spirometer have become the mainstays of postoperative inpatient care. However, a recent Cochrane review of incentive spirometry use in the postcoronary artery bypass graft population with 443 participants in 4 trials found no difference in pulmonary compli- cations amongst incentive spirometry, positive pressure use con- tinuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), or simple preoperative patient education.(53) Furthermore, a meta-analysis with 14 trials over a 26-year period evaluating the use of incentive spirometry, positive pressure, and deep breathing following upper abdominal surgery to prevent postoperative pulmonary complications, also demonstrated no statistically significant difference between these modalities and no therapy alone.(54) Pasquina and colleagues performed a review of 35 trials evaluating the use of respiratory physiotherapy after abdominal surgery and found that only in one study was the incidence of pneumonia decreased. In another study atelectasis decreased from 77% to 59% using pulmonary toilet methods of deep breathing, cough, and postural drainage.(55) They concluded that there are only a few trials that support its use, and the routine use of respiratory physiotherapy does not seem warranted based on data alone. Despite these large reviews, atelectasis is known to be present in anesthetized patients in the dependent portions of the lungs and has been shown to contribute to decreased lung compliance, worse oxygenation, increased pulmonary vascular resistance, and shunting.(56) It seems at worst that the practice of employing methods to decrease atelectasis is not harmful, and at best, may help out to a small degree with avoidance of pulmonary complications, and therefore, it is our continued practice. Pneumonia There is little data in the literature that directly addresses the development of pneumonia following colorectal or anorectal sur- gery. As stated above, the degree to which atelectasis and proper pulmonary toilet corresponds to the development of pneumo- nia is debatable. One thing that is clear is that development of postoperative pneumonia is independently associated with worse outcomes. Therefore, both prevention and early recognition and treatment, are key components to ensuring optimal outcomes. Johnson and colleagues found in a study of 180,359 patients that postoperative respiratory failure (defined as mechanical ventila- tion for longer than 48 hours after initial surgery or unantici- pated reintubation) was found in 5,389 (3.0%) of patients and was associated with an increased in hospital morbidity, cost, and late mortality.(57) Additionally, factors that were found to be independently associated with the development of this was higher ASA classification, emergency operations, more complex surgery, sepsis, older age, congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), and smoking. These, along with a history of obesity and obstructive sleep apnea, man- date a need for careful postoperative monitoring and aggressive pulmonary toilet. Many of the patients, especially with underly- ing malignancy, have these comorbidities, and speak to the com- plexity of operations and need for close surveillance to avoid this feared complication. deep venous thrombosis Deep venous thrombosis (DVT) and its embolic corollary, pul- monary embolism (PE), are a significant source of morbidity and mortality in the perioperative period. Due to the predominance of abdominal and pelvic surgery, colorectal surgery carries a higher risk of these postoperative complications than other general surgical pro- cedures. Yet, despite so much emphasis, DVT and PE continue to be the most common cause of preventable deaths during in-hospital admission, accounting for 1 out of every 4 hospitalized patients deaths.(58, 59) More concerning, over 50% of all DVTs are asymp- tomatic, while the vast majority of PEs are detected only after death (58). Since Virchow’s original description of stasis, hypercoaguability, and endothelial damage as risk factors, large epidemiological studies have found an increase in the development of symptomatic venous  improved outcomes in colon and rectal surgery thromboembolism in the perioperative period to be associated with male gender, malignancy, trauma, immobility, COPD, sepsis, low hematocrit, low albumin, and major surgery.(60) One of the major problems with development of a DVT is the lack of initial clinical signs. Patient complaints of pain, swelling, edema, warmth, and tenderness of the affected limb are often absent.(61) Those patients that progress onto pulmonary embolism present many times in the late stages with cardiopulmonary shock and col- lapse, though often heralded by symptoms such as acute shortness of breath, dyspnea, pleuritic chest pain, along with tachycardia and an increasing oxygen requirement. Thus, emphasis has been placed on both prevention and screening. Despite its very high sensitiv- ity and specificity of over 95%, screening with duplex and color Doppler sonography, even in high risk patients, in the absence of symptoms, has been questioned as to its cost-effectiveness.(62, 63) Part of this may be that although the lower extremities are the most common site of origin, approximately one-third of patients have proximal (above popliteal) veins as the site of origin, which are not visualized well by duplex.(59) Venous ultrasonography remains the mainstay for diagnosis of deep venous thrombosis, especially when combined with elevated d-dimer levels. The hallmarks of DVT via ultrasound are both visualization of the clot and more commonly the inability to compress the venous system under direct pressure. (64) Similarly with the advent of multidetector row helical CT scan- ners, this has essentially supplanted the pulmonary angiogram as the procedure of choice for diagnosis of pulmonary embolism, with sensitivity, specificity, and negative predictive value over 90%, even for subsegmental pulmonary emboli.(65) Prophylaxis of venous thrombotic events centers on both mechanical and medical means. The current mainstays for chemi- cal thromboprophylaxis are unfractionated and low- molecular weight heparin. Unfractionated heparin works through anti- thrombin III to deactivate thrombin and other factors in the clotting cascade. Concerns about increased bleeding events as well as its dose-effect relationship have led many to be wary of its use. Low-molecular weight heparin has enhanced antifactor Xa activ- ity and more predictable dose-effect relationships.(66) In a recent Cochrane review addressing the prevention of thromboembolic complications, the combined use of mechanical graduated stock- ings with either unfractionated or low molecular heparin was identified as the optimal prophylaxis.(67) Interestingly, despite the extensive search, only 3 studies meeting inclusion criteria focused specifically on colon and rectal surgery. That same group evalu- ated 558 studies, of which 19 met the inclusion criteria, and again found that unfractionated and fractionated heparin were equally effective, and the addition of either to compression stockings was superior to either alone.(68) As pointed out in the opening challenging case, risk stratifi- cation continues to be a mainstay for determining the extent of prophylaxis in these patients. Young, healthy patients undergoing routine anorectal surgery, with minimal patient-specific risk fac- tors, do not require any therapy other than mechanical means via graduated compression stockings and/or intermittent pneu- matic compression boots and early ambulation. Those patients with multiple risk factors and undergoing high risk surgery, such as pelvic operations, warrant more aggressive means like unfrac- tionated or low-molecular weight heparin, in addition to the mechanical devices. Timing has been somewhat controversial with some studies demonstrating higher bleeding without undue increase in thrombotic events when given after the surgery and others stating that dosing should begin preoperatively. Although this question has yet to be definitively answered based on cur- rent literature, it is well accepted that some form of perioperative, including intraoperative means, has become the standard of care. The risk of bleeding with thromboprophylaxis dosing is small, with the majority revolving around injection site ecchymoses or hematoma in up to 7% of cases.(69) More clinically significant bleeding, such as gastrointestinal or intraabdominal bleeding, occurs in <0.5%, and is rarely the cause for cessation of therapy. One potential concern that arises frequently in the realm of colorectal surgery is how to treat the patient receiving anticoagu- lation for colonoscopy. Recent guidelines have shown that aspirin and other NSAIDs do not need to be withheld, with the rate of postpolypectomy bleeding around 2%.(70) On the other hand, coumadin and other more potent antiplatelet medications (i.e., clopidogrel) are commonly held for 5 to 7 days before the pro- cedure, especially when it is known that a polypectomy or other procedure is likely. There is some evidence that the application of endoclips with polypectomy in anticoagulated patients is safe; however, small sample sizes hinder ability to make broad recom- mendations.(71) Thus, most of the practice is based on guide- lines and less on an abundance of available evidence supporting or dissuading this practice.(72, 73) nausea and vomitinG Though often not deemed as significant or crucial to overall success of an operation by surgeons, postoperative nausea and vomiting (PONV) can be extremely bothersome for the patient. Clearly, the etiology is multifactorial—with surgical, anesthetic, medication, and patient-related factors all contributing significantly. Head of bed elevation and early ambulation are minor modifications that may be somewhat helpful. More useful, anesthesia providers have found increasing success through prophylaxis for this phenom- enon. As a part of that process, identification of those patients at risk is imperative, as universal prophylaxis has not been shown to be cost-effective.(74) A thorough review of prior surgeries and response to anesthetics may help in identification of these individ- uals. Intravenous use of ondansetron, a selective serotonin 5HT3 receptor antagonist, has been shown in multiple randomized trials to be effective in complete prevention of postoperative emesis in up to 60–85%, when given before the induction of general anesthesia. (75–77) Finally, routine decompression with nasogastric tubes has demonstrated no impact on PONV and has fallen out of favor.(78) prolonGed ileus In general, postoperative obstruction can be divided into two broad categories—early and late. Early postoperative bowel obstruction is defined as onset of symptoms within thirty days of surgery. The majority of early postoperative bowel obstructions are due to para- lytic ileus or adhesions—up to 90 percent in some series, with the remaining possible etiologies including phlegmon, intraabdomi- nal abscess, Crohn’s disease, hernia, volvulus, intussusceptions, and malignancy.(79, 80) Late obstructions are those presenting at any point >30 days following surgery. The management of bowel  general postoperative complications obstruction including ileus remains a significant burden to health- care costs. In 1994, according to Beck and colleagues, there were 303,836 hospitalizations during which adhesiolysis was performed, accounting for 846,415 inpatient days and an estimated $1.3 billion in expenditures.(81) In addition, reoperative surgery in the setting of early bowel obstruction can prove to be significantly challeng- ing, as abdominal inflammation and early adhesions create a hostile environment marked by densely adhered bowel and friable tissues. In order to safely and effectively manage these patients, one must have an extensive understanding of the various conditions which may result in prolonged ileus. Like many of the complications discussed in this chapter, the development of a prolonged ileus has multiple potential causative factors including hormones, medications and sur- gical stress. Postoperative ileus clinically manifests itself with abdominal distension, bloating, failure to pass stool or gas, nau- sea, emesis, and pain. Even more concerning, Senagore found that in addition to the symptoms experienced as a result of the ileus, delayed surgical wound healing and ambulation, atelecta- sis, pneumonia, and deep vein thrombosis are all potentially increased by the development of a postoperative ileus, which increases hospitalization length of stay and overall costs.(82) The definition of what constitutes a prolonged ileus widely varies in the literature and contributes to discrepancies between different studies. In general, when the symptom complex continues for over 7 days following abdominal surgery, most consider this prolonged and should raise concern for more extensive evaluation. Return of bowel function has multiple parameters that can be controlled by the provider in the perioperative period. For exam- ple, limiting the amount of intraoperative and postoperative fluid and sodium has been shown to improve time to passage of flatus and stool, and result in earlier hospital discharge.(83) In addition, clinical pathways that include the use of restricted perioperative intravenous fluids, early oral intake, early ambulation, and epidu- ral anesthesia, have been shown to significantly decrease length of stay and perioperative cardiopulmonary complications, although readmissions are slightly higher.(84) Thus, working through optimization of all components of postoperative care may con- tribute more to a successful recovery than primary emphasis on one factor alone. Through entry into a standardized program, the avoidance of certain variables that negatively affect recovery for both the intraoperative and postoperative settings can pro- vide improved reproducible results.(85) A bonus of implemen- tation of pathways is the ability to help all healthcare providers, including nursing personnel, to become accustomed to a routine postbowel resection course. Therefore, any deviations from this can be recognized more readily, allowing intervention before the patient enters a more severe or septic state. A thorough history and physical examination help distinguish some of the benign causes of obstruction and aid in differentiating this from a prolonged ileus. For example, the history in a patient with Crohn’s disease or prior radiation therapy can provide just as many clues as to the etiology of the obstruction, such as pos- sible stricture, or an obvious hernia detected on physical exami- nation. As patients often present with concomitant dehydration and electrolyte abnormalities, placement of a nasogastric tube, with appropriate fluid resuscitation, and correction of electrolyte abnormalities should occur while the work-up is in progress. Plain film radiographs may confirm dilated small bowel loops with stair-stepping air-fluid levels, but usually do not assist in defin- ing the underlying etiology. Despite their frequent use, numerous studies quote a poor sensitivity for plain abdominal radiographs in diagnosis of small bowel obstruction, ranging from 13% for low grade obstruction to 50–60% for high grade obstructions. (86) CT may give anatomical information outside of the bowel wall itself that may help with accurate diagnosis. Caution should be used in giving oral contrast for the patient with high grade ileus or obstruction, and in general, should be avoided. Newer pharmacotherapeutic endeavors, such as the peripher- ally acting mu-opioid receptor antagonist, alvimopan, have been shown to reduce the incidence of postoperative ileus, nasogas- tric tube insertion, time to gastrointestinal recovery, and overall hospital length of stay.(87–89) Further studies are still ongoing to evaluate whether its safety profile is acceptable for wide-scale clinical use. Other methods that have been studied in attempt to shorten bowel function return include prokinetic agents such as erythromycin and cisapride, although the results have been mixed. Erythromycin, a motilin agonist, has been shown in the past to be effective for upper gastric and pancreatic surgery, especially with regard to promotion of gastric emptying. In a randomized double- blind placebo study of 134 patients, erythromycin was not shown to affect clinically relevant outcomes such as time to intake of solid foods, nausea rate, or length of stay.(90, 91) Similarly, cisapride, before its removal from the market secondary to cardiac toxicity, did show some, albeit limited, clinically significant improvements. (92–94) Thus, for hindgut surgery, prokinetic agents have not yet been shown to make a clinically relevant difference. Probably the most important factor that has been shown to make a difference in reducing ileus is postoperative clinical pathways that include early oral feeding.(95) A recent Cochrane review by Andersen et al. including 13 randomized controlled trials and over 1,100 patients, evaluated the use of early feeding and the development of complications and found early feeding is safe, may reduce postsurgical complications, and concluded there is no advantage to withholding oral intake.(96) Opponents of this practice cite a lack of a consistent definition of what early feeding encompasses. As such, although many surgeons prefer to advance the postoperative diet slowly, it does seem clear that the recovery of gastrointestinal function as evidenced by first bowel movement or flatus and tolerance of an oral diet in the early post- operative setting are independent of each other, and the practice of early resumption of diet is safe.(97) retained foreiGn bodies In any complex surgical procedure there exists a potential for items to be unknowingly left in body cavities.(98) To minimize this risk, current standards require all sponges, needles, surgical instru- ments, equipment, and items small enough to be misplaced be counted before the procedure and one or two times after the com- pletion of the procedure to confirm that all items are accounted for. These activities are usually performed and documented by the operating room nurses and technicians; however, the surgeon is ultimately responsible and should conduct each operation so as to minimize the risk of misplaced foreign bodies. In accordance with  improved outcomes in colon and rectal surgery this goal, most surgeons, avoid using small Ray-tec sponges in the abdomen and avoid placing laparotomy sponges in areas that are hard to visualize. If sponges must be used to pack areas, the sponge marker should be left in an obvious area, or a ring or clamp may be attached to the sponge. Most important is a through explo- ration of the entire operative field, which should be performed routinely before closing the incision. Items used during the opera- tion that have the potential to be easily lost should be radiopaque or contain a radiopaque marker (e.g., Ray-tec sponges and Silastic drains). Figures 8.2 and 8.3 demonstrate the radiologic view of several common surgical items. Plain radiographs are often the best for identifying the radiopaque markers incorporated into these items; The markers may be much less obvious on studies such as CT scans (Figures 8.4a and b). If an instrument, sponge, or needle count is not correct, several actions are indicated. All the sponge wrappers and suture pack- ages should be counted to confirm the accuracy of the original count. The entire operating room, and especially the trash bags and floor under the operating table, should be searched for the misplaced item. Simultaneously, the surgeon should inspect the operative field thoroughly for the missing item. If the missing item cannot be located, a radiograph of the entire operating field Figure 8.2 Radiograph demonstrating radoopaque markers. Left to right. Laparotomy sponge, Ray-tec sponge. The upper image is flattened, whereas the lower image demonstrates the radiologic view when the item is crumpled. Figure 8.3 Radiograph of (left to right) Jackson-Pratt drain, Penrose drain, nasogastric tube. Figure 8.4 (A) CT scan of patient with a retained Ray-tec sponge. Image is the inferior cut of the study. The upper edge of the Ray-tec marker is demonstrated as white dots lines between the bladder (filled with contrast) and the sacrum. (B) Pelvic radiograph of the same patient demonstrating Ray-tec marker in pelvis. (A) (B)  general postoperative complications should be obtained before closure of the body cavity to identify any radiopaque object and minimize the morbidity of locating the missing item. Because of the potential for human error, a “correct” instrument, needle, or sponge count does not absolutely exclude the presence of a foreign body. Therefore, each member of the team must maintain a high index of suspicion. A sponge or other foreign body left in a body cavity can pres- ent or be identified in a number of ways. The foreign body may be seen on a radiograph obtained for other reasons, or the patient may develop symptoms that lead to the need for radiographs or an exploratory procedure. Symptoms may be infectious (fever, elevated white cell count, wound infection, or abscess) or inflam- matory (ileus, tenderness, mass effect). For any postoperative patient with unusual or unexplained symptoms, radiographs should be included in the evaluation. Finding a retained foreign body is unusually an indication for an urgent exploratory procedure. The exception may be asymp- tomatic patient with a retained small needle. The morbidity associ- ated with localizing and removing a small needle must be weighed against the potential risk of leaving it alone, and the patient can assist in this decision. Review of biplanar radiographs may assist in localizing a retained item, and early identification will minimize the morbidity associated with the object’s removal. Retention of operative foreign bodies is uncommon, and a surgical team that adheres to careful practices should avert its occurrence. “time out” and sided surGery concerns Wrong-side/wrong site, wrong-procedure, wrong-patient adverse events (WSPEs) constitute some of the worst medical errors that cli- nicians and patients experience. These events often result in patient harm and litigation, but literature on frequency and root causes is limited.(99) The Institute of Medicine report To Err Is Human painted a broad picture of the magnitude of medical errors in the United States and gave directions for safety improvements.(100) While, sided surgery is less of a concern in colorectal patients, incor- rect surgery due to inadequate lesion location remains a challenge. In July 2004, the Joint Commission on the Accreditation of Healthcare Organizations (JCAHO) implemented the universal protocol for the prevention of WSPEs.(101) The protocol uses preoperative verifica- tion of patient, site, and procedure, marking the operative site, and a time-out immediately before starting the procedure. Prevention of WSPEs requires new and innovative technologies, reporting of case occurrence, and learning from successful safety initiatives (such as in transfusion medicine and other high-risk nonmedical industries), while reducing the shame associated with these events. future directions As the push to not only prevent complications but detect them earlier continues to expand, molecular markers may become an increasingly utilized component. Welsch and associates evaluated the use of C-reactive protein (CRP) in the postoperative course of 383 rectal resections with primary anastomosis in patients with rectal cancer and found that using a cutoff of levels above 140 mg/dl on postoperative days 3 and 4 was associated with a sensitivity of 80 and 54% respectively and specificities of 81 and 92%, respectively, for the presence of all infectious complications. (102) Although this is just one example of a vast field, it highlights a growing trend toward bridging the gap between molecular and bench research with clinical application in attempt to change the way surgeons approach patients and improve outcomes. conclusion As the field of colon and rectal surgery continues to evolve as a specialty, emphasis on optimization of outcomes through pre- vention and early identification, and treatment of complications is imperative. As many complications are a result of multiple dif- ferent components, sometimes all working in concert to lead to untoward results, surgeons must also use a multifaceted approach to ensure a successful perioperative course. references 1. Sparling KW, Ryckman FC, Schoettker PJ et al. Financial impact of failing to prevent surgical site infections. Qual Manag Health Care 2007; 16(3): 219–25. 2. Jensen MP, Chen C, Brugger AM. Postsurgical pain outcome assessment. Pain 2002; 99(1–2): 101–9. 3. Sim R, Cheong DM, Wong KS, Lee BM, Liew OY. Prospective randomized, double-blind, placebo-controlled study of pre- and postoperative administration of a COX-2 specific inhibitor as opioid-sparing analgesia in major colorectal surgery. Colorectal Dis 2007; 9(1): 52–60. 4. Cepeda MS, Carr DB, Miranda N et al. Comparison of mor- phine, ketorolac, and their combination for postoperative pain: results from a large, randomized, double-blind trial. Anesthesiology 2005; 103(6): 1225–32. 5. Armstrong DN, Ambroze WL, Schertzer ME, Orangio GR. Harmonic Scalpel ® vs. electrocautery hemorrhoidectomy: a pro- spective evaluation. Dis Colon Rectum 2001; 44(4): 558–64. 6. Place RJ, Coloma M, White PF et al. Ketorolac improves recovery after outpatient anorectal surgery. Dis Colon Rectum 2000; 43(6): 804–8. 7. Sun MY, Canete JJ, Friel JC et al. Combination propofol/ ketamine is a safe and efficient anesthetic approach to ano- rectal surgery. Dis Colon Rectum 2006; 49(7): 1059–65. 8. Read TE, Henry SE, Hovis RM et al. Prospective evaluation of anesthetic technique for anorectal surgery. Dis Colon Rectum 2002; 45(11): 1553–8. 9. Polglase AL, McMurrick PJ, Simpson PJ et al. Continuous wound infusion of local anesthetic for the control of pain after elective abdominal colorectal surgery. Dis Colon Rectum 2007; [Epub ahead of print]. 10. Beaussier M, El’Ayoubi H, Schiffer E et al. Continuous preperitoneal infusion of ropivacaine provides effective analgesia and accelerates recovery after colorectal surgery: a randomized, double-blind, placebo-controlled study. Anesthesiology 2007; 107(3): 461–8. 11. Baig MK, Zmora O, Derdemezi J et al. Use of the ON-Q pain management system is associated with decreased post- operative analgesic requirement: double blind randomized placebo pilot study. J Am Coll Surg 2006; 202(2): 297–305. 12. Marret E, Remy C, Bonnet F. Postoperative Pain Forum Group. Meta-analysis of epidural analgesia versus parenteral opioid analgesia after colorectal surgery. Br J Surg 2007; 94(6): 665–73.  improved outcomes in colon and rectal surgery 13. Gendall KA, Kennedy RR, Watson AJ, Frizelle FA. The effect of epidural analgesia on postoperative outcome after colorectal surgery. Colorectal Dis 2007; 9(7): 584–98. 14. Carli F, Trudel JL, Belliveau P. The effect of intraoperative thoracic epidural anesthesia and postoperative analgesia on bowel function after colorectal surgery: a prospective, randomized trial. Dis Colon Rectum 2001; 44(8): 1083–9. 15. Ho KY, Gan TJ, Habib AS. Gabapentin and postoperative pain–a systematic review of randomized controlled trials. Pain 2006; 126(1–3): 91–101. 16. Tiippana EM, Hamunen K, Kontinen VK, Kalso E. Do surgical patients benefit from perioperative gabapentin/pregabalin? A systematic review of efficacy and safety. Analg 2007; 104(6): 1545–56. 17. Hayssen T, Luchtefeld M, Senagore A. Limited hemorrhoid- ectomy: results and long-term follow-up. Dis Colon Rectum 1999; 42(7): 909–15. 18. Khan S, Pawlak SE, Eggenberger JC et al. Surgical treatment of hemorrhoids: prospective, randomized trial comparing closed excisional hemorrhoidectomy and the Harmonic Scalpel technique of excisional hemorrhoidectomy. Dis Colon Rectum 2001; 44(6): 845–9. 19. Chung CC, Ha JP, Tai JP, Tsang WW, Li MK. Double-blind, randomized trial comparing Harmonic Scalpel TM hem- orrhoidectomy, bipolar scissors hemorrhoidectomy, and scissors excision. Dis Colon Rectum 2002; 45: 789–94. 20. Mynster T, Nielsen HJ, Harling H et al. Blood loss and trans- fusion after total mesorectal excision and conventional rectal cancer surgery. Colorectal Dis 2004; 6(6): 452–7. 21. Kiran RP, Delaney CP, Senagore AJ, Millward BL, Fazio VW. Operative blood loss and use of blood products after laparoscopic and conventional open colorectal operations. Arch Surg 2004; 139(1): 39–42. 22. Gencosmanoglu R, Sad O, Koc D, Inceoglu R. Hemorrhoidectomy: Open or closed technique? A prospective, randomized clinical trial. Dis Colon Rectum 2002; 45: 70–5. 23. Harrison JL, Hooks VH, Pearl RK et al. Muscle fragment welding for control of massive presacral bleeding dur- ing rectal mobilization: a review of eight cases. Dis Colon Rectum 2003; 46: 1115–7. 24. Nivatvongs S, Fang DT. The use of thumbtacks to stop massive presacral hemorrhage. Dis Colon Rectum 1986; 29: 589–90. 25. Khan FA, Fang DT, Nivatvongs S. Management of presacral bleeding during rectal resection. Surg Gynecol Obstet 1987; 165: 274–6. 26. Hill AD, Menzies-Gow N, Darzi A. Methods of controlling presacral bleeding. J Am Coll Surg 1994; 178: 183–4. 27. Losanoff JE, Richman BW, Jones JW. Cyanoacrylate adhe- sive in management of severe presacral bleeding. Dis Colon Rectum 2002; 45: 1118–9. 28. Cosman BC, Lackides GA, Fisher DP, Eskenazi LB. Use of tissue expander for tamponade of presacral hemorrhage. Report of a case. Dis Colon Rectum 1994; 37: 723–6. 29. Qinyao W, Weijin S, Youren Z et al. New concepts in severe presacral hemorrhage during proctectomy. Arch Surg 1985; 120: 1013. 30. Corman ML. Colon & Rectal Surgery. 5th ed. Philadelphia. Lippincott Williams & Wilkins 2004. 31. Blumetti J, Luu M, Sarosi G et al. Surgical site infections after colorectal surgery: do risk factors varying depending on the type of infection considered? Surgery 2007; 142(5): 704–11. 32. Gendall KA, Raniga S, Kennedy R, Frizelle FA. The impact of obesity on outcome after major colorectal surgery. Dis Colon Rectum 2007; [Epub ahead of print]. 33. Fujita S, Saito N, Yamada T et al. Randomized, multicenter trial of antibiotic prophylaxis in elective colorectal surgery: single dose vs. 3 dose of a second-generation cephalosporin without metronidazole and oral antibiotics. Arch Surg 2007; 142(7): 657–61. 34. Espin-Basany E, Sanchez-Garcia JL, Lopez-Cano M et al. Prospective, randomised study on antibiotic prophylaxis in colorectal surgery. Is it really necessary to use oral antibiot- ics? Int J Colorectal Dis 2005; 20(6): 542–6. 35. Kobayashi M, Mohri Y, Tonouchi H et al. Mie Surgical Infection Research Group. Randomized clinical trial com- paring intravenous antimicrobial prophylaxis alone with oral and intravenous antimicrobial prophylaxis for the prevention of a surgical site infection in colorectal cancer surgery. Surg Today 2007; 37(5): 383–8. 36. Lewis RT. Oral versus systemic antibiotic prophylaxis in elective colon surgery: a randomized study and meta- analysis send a message from the 1990s. Can J Surg 2002; 45(3): 173–80. 37. Ishida H, Yokoyama M, Nakada H, Inokuma S, Hashimoto D. Impact of oral antimicrobial prophylaxis on surgi- cal site infection and methicillin-resistant Staphylococcus aureus infection after elective colorectal surgery. Results of a prospective randomized trial. Surg Today 2001; 31(11): 979–83. 38. Belda FJ, Aguilera L, Garcia de la Asuncion J et al. Spanish Reduccion de la Tasa de Infeccion Quirurgica Group. Supplemental perioperative oxygen and risk of surgical wound infection: a randomized controlled trial. JAMA 2005; 294(16): 2035–42. 39. Greif R, Akca O, Horn EP, Kurz A, Sessler DI. Supplemental perioperative oxygen to reduce the incidence of surgical- wound infection. Outcomes Research Group. N Engl J Med 2000; 342(3): 161–7. 40. Niël-Weise BS, van den Broek PJ. Antibiotic policies for short-term catheter bladder drainage in adults. Cochrane Database Syst Rev 2005; (3): CD005428. 41. Benoist S, Panis Y, Denet C et al. Optimal duration of urinary drainage after rectal resection: a randomized controlled trial. Surgery 1999; 125(2): 135–41. 42. Zaheer S, Reilly WT, Pemberton JH, Ilstrup D. Urinary retention after operations for benign anorectal diseases. Dis Colon Rectum 1998; 41(6): 696–704. 43. Changchien CR, Yeh CY, Huang ST et al. Postoperative uri- nary retention after primary colorectal cancer resection via laparotomy: a prospective study of 2,355 consecutive patients. Dis Colon Rectum 2007; 40: 1688–96. 44. Ratnaval CD, Renwick P, Farouk R, Monson JR, Lee PW. Suprapubic versus transurethral catheterisation of males undergoing pelvic colorectal surgery. Int J Colorectal Dis 1996; 11(4): 177–9.  general postoperative complications 45. Branagan GW, Moran BJ. Published evidence favors the use of suprapubic catheters in pelvic colorectal surgery. Dis Colon Rectum 2002; 45(8): 1104–8. 46. Cataldo PA, Senagore AJ. Does alpha sympathetic blockade prevent urinary retention following anorectal surgery? Dis Colon Rectum 1991; 34(12): 1113–6. 47. Petros JG, Bradley TM. Factors influencing postoperative urinary retention in patients undergoing surgery for benign anorectal disease. Am J Surg 1990; 159(4): 374–6. 48. Toyonaga T, Matsushima M, Sogawa N et al. Postoperative urinary retention after surgery for benign anorectal dis- ease: potential risk factors and strategy for prevention. Int J Colorectal Dis 2006; 21(7): 676–82. 49. Hoff SD, Bailey HR, Butts DR et al. Ambulatory surgical hemorrhoidectomy—a solution to postoperative urinary retention? Dis Colon Rectum 1994; 37(12): 1242–4. 50. Main E, Prasad A, Schans C. Conventional chest physio- therapy compared to other airway clearance techniques for cystic fibrosis. Cochrane Database Syst Rev 2005; (1): CD002011. 51. Berlly M, Shem K. Respiratory management during the first five days after spinal cord injury. J Spinal Cord Med 2007; 30(4): 309–18. 52. Orringer MB, Marshall B, Chang AC et al. Two thousand transhiatal esophagectomies: changing trends, lessons learned. Ann Surg 2007; 246(3): 363–72. 53. Freitas ER, Soares BG, Cardoso JR, Atallah AN. Incentive spirometer for preventing pulmonary complications after coronary artery bypass grafting. Cochrane Database Syst Rev 2007; (3): CD004466. 54. Thomas JA, McIntosh JM. Are incentive spirometry, inter- mittent positive pressure breathing, and deep breathing exercises effective in the prevention of postoperative pul- monary complications after upper abdominal surgery? A systematic overview and meta-analysis. Phys Ther 1994; 74(1): 3–10. 55. Pasquina P, Tramer MR, Granier JM, Walder B. Respiratory physiotherapy to prevent pulmonary complications after abdominal surgery: a systematic review. Chest 2006; 130(6): 1887–99. 56. Duggan M, Kavanagh BP. Atelectasis in the perioperative patient. Curr Opin Anaesthesiol 2007; 20(1): 37–42. 57. Johnson RG, Arozullah AM, Neumayer L et al. Multivariable predictors of postoperative respiratory failure after gen- eral and vascular surgery: results from the patient safety in surgery study. J Am Coll Surg 2007; 204(6): 1188–98. 58. Nutescu EA. Assessing, preventing, and treating venous thromboembolism: evidence-based approaches. Am J Health Syst Pharm 2007; 64(11 Suppl 7): S5–13. 59. Anaya DA, Nathens AB. Thrombosis and coagulation: deep vein thrombosis and pulmonary embolism prophylaxis. Surg Clin North Am 2005; 85(6): 1163–77. 60. Gangireddy C, Rectenwald JR, Upchurch GR, Wakefield TW, Khuri S, Henderson WG, Henke PK. Risk factors and the clinical impact of postoperative symptomatic venous thromboembolism. J Vas Surg 2007; 45(2): 335–41. 61. Blann AD, Lip GYH. Venous thromboembolism. BMJ 2006; 332(7535): 215–9. 62. Davidson HC, Mazzu D, Gage BF, Jeffrey RB. Screening for deep venous thrombosis in asymptomatic postoperative orthopedic patients using color Doppler sonography: anal- ysis of prevalence and risk factors. AJR Am J Roentgenol 1996; 166(3): 659–62. 63. Gaitini D. Current approaches and controversial issues in the diagnosis of deep vein thrombosis via duplex Doppler ultrasound. J Clin Ultrasound 2006; 34(6): 289–97. 64. Wells PS. Integrated strategies for the diagnosis of venous thromboembolism. J Thromb Haemost 2007; 5(Suppl 1): 41–50. 65. Schoepf UJ, Schneider AC, Das M et al. Pulmonary embolism: computer-aided detection at multidetector row spiral com- puted tomography. J Thorac Imaging 2007; 22(4): 319–23. 66. Büller HR, Agnelli G, Hull RD et al. Antithrombotic ther- apy for venous thromboembolic disease: the seventh ACCP conference on antithrombotic and thrombolytic therapy. Chest 2004; 126(3 Suppl): 401S–428S. 67. Wille-Jorgensen P, Rasmussen MS, Andersen BR, Borly L. Heparins and mechanical methods for thromboprophylaxis in colorectal surgery. Cochrane Database Syst Rev 2003; (4): CD001217. 68. Borly L, Wille-Jorgensen P, Rasmussen MS. Systematic review of thromboprophylaxis in colorectal surgery—an update. Colorectal Dis 2005; 7(2): 122–7. 69. Leonardi MJ, McGory ML, Ko CY. The rate of bleeding com- plications after pharmacologic deep venous thrombosis pro- phylaxis: a systematic review of 33 randomized controlled trials. Arch Surg 2006; 141(8): 790–7. 70. Hui AJ, Wong RM, Ching JY et al. Risk of colonoscopic polypectomy bleeding with anticoagulants and antiplatelet agents: analysis of 1657 cases. Gastrointest Endosc 2004; 59(1): 44–8. 71. Friedland S, Soetikno R. Colonoscopy with polypectomy in anticoagulated patients. Gastrointest Endosc 2006; 64(1): 98–100. 72. Dunn AS, Turpie AG. Perioperative management of patients receiving oral anticoagulants: a systematic review. Arch Int Med 2003; 163(8): 901–8. 73. Kearon C, Hirsh J. Management of anticoagulation before and after elective surgery. New Engl J Med 1997; 336(21): 1506–11. 74. Habib AS, Gan TJ. Evidence-based management of postop- erative nausea and vomiting: a review. Can J Anaesth 2004; 51(4): 326–41. 75. McKenzie R, Sharifi-Azad S, Dershwitz M et al. A random- ized, double-blind pilot study examing the use of intrave- nous ondansetron in the prevention of postoperative nausea and vomiting in female inpatients. J Clin Anesth 1993; 5(1): 30–6. 76. Kovac AL, O’Connor TA, Pearman MH et al. Efficacy of repeat intravenous dosing of ondansetron in controlling postoperative nausea and vomiting: a randomized, double- blind, placebo-controlled multicenter trial. J Clin Anesth 1999; 11(6): 453–9. 77. Kovac AL, Pearman MH, Khalil SN et al. Ondansetron prevents postoperative emesis in male outpatients. S3A-379 Study Group. J Clin Anesth 1996; 8(8): 644–51. . 8 improved outcomes in colon and rectal surgery a narcotic-sparing role. In a study of over 1,000 patients, the addi- tion of ketorolac to standard intravenous morphine significantly. Colon Rectum 199 1; 34(12): 1113–6. 47. Petros JG, Bradley TM. Factors influencing postoperative urinary retention in patients undergoing surgery for benign anorectal disease. Am J Surg 199 0;. intravenous dosing of ondansetron in controlling postoperative nausea and vomiting: a randomized, double- blind, placebo-controlled multicenter trial. J Clin Anesth 199 9; 11(6): 453 9. 77. Kovac