Standard of Care Conference: Intra-Abdominal Infections Michael Seneff M.D. Associate Professor Anesthesiology & Critical Care Medicine The George Washington School of Medicine Goals of “Standard of Care” • Identify disease processes frequently requiring surgical evaluation and intervention • Review the recent literature concerning diagnosis, management, and operative treatment – focus on areas of controversy or diverse clinical practice • Present findings to the faculty and residents to develop a datadriven standard practice • Diseases reviewed of interest to multiple specialties- including ED, GI, Critical Care, ID • Appendicitis, small bowel obstruction (SBO), pancreatitis, biliary disease, diverticulitis Acute Appendicitis Introduction The inflammation of the appendix is the most common cause of acute abdomen in young adults. Most frequently performed urgent abdominal operation Incidence Relatively rare in infants Common in childhood and early adult life reaching a peak incidence in the teens and early 20s. Etiology Luminal obstruction by a faecolith or a stricture Proliferation of bacteria Occasionally obstruction to the lumen of the appendix may be due to a tumour of the caecum appendicitis Appendicitis: Diagnosis • WBC – single value not reliable to diagnose appendicitis – serial WBC used w/ serial exam useful in equivocal cases • CT scan – best value if used only after surgical examination – best with PO/ IV/rectal contrast, 5 mm cuts through lower abdomen/pelvis – no prospective, randomized trials – focused helical scan w/ rectal contrast only may be sufficient compared to triple-contrast scan Appendicitis: Antibiotics • Antibiotics – single dose of pre-operative antibiotics warranted – duration of antibiotics for perforated appy not defined -> minimum of 5 days vs. clinically guided decisions • retrospective studies support discontinuing abx when WBC nl and < 3% bands, tol POs, temp < 38 for 24 h • 24 hours for resectable infection (ie gangrenous) • may switch to PO abx when tolerating diet Appendicitis: Operative Approach • Operative management – lap appy -> decreased pain, decreased LOS, decreased wound infections, fewer unestablished diagnoses – open appy -> decreased intra-abdominal abscess formation, lower operative costs w/ open appy – intraoperative cultures are of no utility – copious irrigation (NS vs. abx solution not defined) – literature suggests that both simple and complex appendectomy wounds may be closed primarily Appendicitis: Perforation • Perforated appendicitis – perforated appendix w/ peri-appendiceal mass treated non-operatively w/ IVF, IV abx • worsening exam requires abscess drainage or operation if perc drainage fails • may change to PO abx when afebrile 24 h, tol diet – perforated appendix w/out mass • non-operative failure in 5%, 6 % recurrence in 6 months • complications in 10% – interval appendectomy if recurrent appendicitis, persistent abd pain; colonoscopy if over 50 ANSWER: E. Go straight to surgery Ultrasonography Transverse abdominal US demonstrates a noncompressible mixed echotexture mass in the RLQ consistent with appendiceal abscess/phlegmon. Acute Appendicitis on CT The arrow points to an area of soft tissue induration within the retrocecal fat. There is a rim like area of higher attenuation within this area that is fluid filled. An axial slice of a CT scan done with intravenous and oral contrast that is compatible with a diagnosis of acute appendicitis. The presence of rupture cannot be excluded. Appendicitis Protocol SUSPECTED APPENDICITIS surgical assessment appendicitis OR for appy, single appendicitis pre-op dose IV abx diagnosis unclear long time course CT scan perforation w/ abscess or mass perforation IV abx, supportive care simple gangrenous perforated worsening exam no improvement abscess drainage no abx 24 hr abx abx until afebrile 24 hrs, WBC < 10 all abx may be changed to oral when tol POs improve improve PO abx 1-2 wks colonoscopy if > 50 yrs interval appendectomy PRN rx Biliary Disease: Antibiotics • Antibiotics – biliary colic patients do not need prophylactic antibiotics EXCEPT diabetics and immunosuppressed patients – most patients with acute cholecystitis can be adequately managed with a single preoperative dose – gangrenous cholecystitis warrants 24 hours post-op abx – more complex patients (perforated cholecystitis, cholangitis) require longer duration post-op abx – abx should cover bile pathogens and achieve good MIC in bile -> Zosyn is drug of choice Biliary Disease: Operative Choices • Timing of surgery – urgent LC (<48 hours after symptom onset) is associated w/ better outcomes (conversion, hospital stay, complications) – cholecystostomy tube provides an alternative in pts not able to tolerate an operation • Common bile duct stones – very high-risk patients should undergo ERCP – patients at moderate risk, decreasing LFTs should have IOC at time lap chole – others can be safely treated with LC without imaging of biliary tract (i.e. LFTs rapidly normalize) Biliary Disease: Management Issues • Postoperative LFTs – 24 hour tests frequently show spurious elevations – no data supporting use of LFTs as screening test for complications • Asymptomatic gallstones – diabetics with asymptomatic cholelithiasis can be managed expectantly – cirrhotics are clearly at high risk and should be operated on early when sx develop in Childs A/B – data is not clear on transplantation patients and recommendations tend to be center specific; however, early operation when sx develop is warranted Biliary Colic Protocol SUSPECTED BILIARY COLIC (episodic postprandial pain, nl LFT, nl WBC, no fever) USG gallstones, nl CBD no gallstones assess infection risk low no pre-op abx high (DM, immunosuppressed) single dose abx pre-op OR for elective lap chole abnormal sx, prolonged stay? no no LFTs, routine F/U further eval (EGD, CT, GB ejection) yes LFTs, further eval Acute Biliary Disease Protocol SUSPECTED CHOLECYSTITIS (abd pain > 8 h w/ RUQ tenderness, + WBC/fever, + nl LFTs) USG cholecystostostomy tube poor surg candidate uncomp acute cholecystitis ? no gallstones gallstones comp acute cholecystitis (CBD < 5 mm, LFTs nl) symptomatic CBD stone + pancreatitis (CBD > 5 mm, > 2 LFTs elev.) (CBD < 5 mm, > 2 LFTs elev.) single dose abx pre-op further eval (HIDA, CT) ERCP single dose abx pre-op single dose abx pre-op single dose abx pre-op OR lap chole OR lap chole w/ IOC normal/edematous GB no abx OR lap chole gangrenous GB 24 hr OR lap chole w/ CBDE perforated GB abx 2-5 days abx abnormal sx, prolonged stay? no no LFTs, routine F/U yes LFTs, further eval Acute Cholecystitis2 • Thickened gallbladder wall or edema • Pericholecystic Fluid • Sonographic Murphy’s Sign Acute Cholecystitis Slide 1 U/S of GB pathology Slide 2 CT scan of GB pathology Slide 3 CT scan of GB complications Slide 4 Contrast studies of bile ducts Figure 1. Acute cholecystitis Bortoff G A et al. Radiographics 2000;20:751-766 ©2000 by Radiological Society of North America Figure 11. Transient increased attenuation in the liver adjacent to the gallbladder in a patient with pathologically proved acute cholecystitis Bortoff G A et al. Radiographics 2000;20:751-766 ©2000 by Radiological Society of North America Figure 14. Hemorrhagic cholecystitis Bortoff G A et al. Radiographics 2000;20:751-766 ©2000 by Radiological Society of North America Figure 15. Hepatic abscess related to acute cholecystitis Bortoff G A et al. Radiographics 2000;20:751-766 ©2000 by Radiological Society of North America Conclusions • LC compared with OC has decreased pain and disability without an increase in morbidity or mortality • LC is more cost-effective • Outcome of LC influenced by expertise of surgeon • ASA scale useful but difficult to classify all patients • Percutaneous cholecystostomy useful alternative in ASA IV, V patients BUT 50% still require surgery15 • Conversion from laparoscopic to open cholecystectomy should not be viewed as a complication • Conversion must occur if anatomy is obscured or excessive bleeding occurs18 Diverticulitis: Diagnosis • Imaging studies – not required for clinical diagnosis – CT scan test of choice -> 95% sensitivity • use if diagnosis unclear, empiric medical management has failed, unusual presentation, immunocompromised patients • “diverticular abscess” may be perforated colon cancer in >20% – no role for endoscopy in the acute setting – contrast enemas may enlarge perforation Diverticulitis: Management • Medical therapy – outpatient treatment w/ PO abx if maintaining oral intake clear liquids – severe pain, ileus need inpatient admission • NPO, IVF, IV abx -> change to oral abx when tolerating POs • total antibiotic course 7-10 days • Colonoscopy 6 weeks after resolution of acute episode Diverticulitis: Complicated Disease • Diverticulitis with intra-abdominal abscess – 50% improve on antibiotics alone, 14-day course – percutaneous drainage if no improvement in 72 hours or sooner if clinically deteriorating – single catheter for multiloculated collection vs multiple catheters for septated abscesses • > 2 catheters -> likely need for surgery • > 50 cc after 1st 24 hours -> c/w fistula – no resolution 72 hours after drainage -> surgery Diverticulitis: Operative Indicators • Indications for operative intervention – – – – – – – diffuse peritonitis unresolving obstruction fistula symptomatic stricture failure medical therapy recurrent attacks -> elective operation immunosuppression • 30% of patients w/ recurrent attacks will require surgery Diverticulitis: Operative Approaches • Operative options – single-stage for Hinchey I,II (pericolonic abscess or larger abscess) -> • abscess drainage, resection, primary anastamosis – two-stage for Hinchey III, IV (purulent peritonitis, feculent peritonitis) • drainage, removal diseased segment, colostomy • re-anastamosis and takedown colostomy at second operation – no role for three-stage operation Hinchey Classification Scheme Hinchey 1 - peri-diverticular abscess within the mesocolon Hinchey II - distant (pelvic, retroperitoneal) abscess Hinchey III - generalized purulent peritonitis Hinchey IV – generalised faecal peritonitis Jacobs D. N Engl J Med 2007;357:2057-2066 Who needs operation? • Hinchey I - conservative • Hinchey II distal or large abscess > 4cm: CT drainage – Less than 10% of Hinchey I and II need operation • Hinchey III – usually operation • Hinchey IV – always operation CT Scans of the Colon in Four Patients with Diverticulitis of Varying Severity 56-year-old woman admitted for first episode of acute diverticulitis. Transverse CT scan shows concentric wall thickening (arrow) of descending colon with area of adjacent fatty infiltration (arrowheads). Patient underwent 10 days of IV antibiotic treatment and was discharged home free of symptoms. Patient relapsed 2 months later; she was readmitted to hospital for new antibiotic treatment and scheduled for elective surgery. 48-year-old man admitted for acute diverticulitis. Axial CT scan shows wall thickening of horizontal aspect of sigmoid colon (arrowheads). Bubbles of extraintestinal gas (< 5 mm diameter) (arrow) are seen in area of fat infiltration. Diverticulitis resolved with nonoperative treatment. 76-year-old woman admitted for first episode of acute diverticulitis. She underwent nonoperative treatment with IV antibiotics. Her general condition improved initially, but she relapsed 8 days after admission. She underwent sigmoidectomy 3 months later. Transverse CT scan shows thickening (arrowheads) of wall of horizontal aspect of sigmoid colon with associated local fat infiltration (arrow). 89-year-old man admitted for first episode of acute diverticulitis. Transverse pelvic CT scan shows thickened wall of distal sigmoid colon with narrowed lumen, filled by thin strip of intraintestinal contrast media (arrowhead). Cavity containing air–fluid level corresponding to abscess (arrow) is located adjacent to thickened sigmoid segment. Patient underwent IV antibiotic treatment, and abscess was drained under CT guidance. General condition improved, and patient was discharged home 2 weeks later with normal clinical examination and normal WBC. Three months later, he was readmitted to hospital with perforation of sigmoid colon and massive pneumoperitoneum seen on CT examination (not shown). He underwent emergent sigmoidectomy with colostomy (Hartmann procedure) and died soon after surgery. 85-year-old woman admitted for acute diverticulitis. She recovered with antibiotic therapy and had no recurrence of diverticulitis. CT scan shows free peritoneal fluid (arrows) in right paracolic gutter and in mesosigmoid; infiltration of perisigmoid fatty tissue (arrowheads) is also shown. Summary • Most people in the Western World will develop diverticulae • Most will remain asymptomatic • The most serious complication is fecal perforation (stercoral ulcer-43% mortality) – most likely to occur at first attack • After first attack of complicated diverticulitis 10% recur in the first year – then 3% per year Diverticulitis Protocol peritonitis free perf immunosuppressed ACUTE DIVERTICULITIS home on PO abx POs no POs 7-10 day total OR (1 or 2 stage) fistula admission, IVF, IV abx no improvement free air no collection CT scan failure to improve 72 hours improved clears, PO abx no abscess 14-day total abscess improved deterioration continue IV abx deterioration perc drainage failure to improve 72 hours OUTPATIENT COLONOSCOPY AT 6 WEEKS Pancreatitis: Definitions • Simple acute pancreatitis – 80% of cases of pancreatitis – mild, self-limited course that resolves w/ supportive care • Complicated acute pancreatitis – 20% of cases – develop severe, potentially life-threatening disease characterized by variable amounts of pancreatic necrosis • high risk for MSOF, infection of pancreatic necrosis, death Pancreatitis: Diagnosis • Laboratory tests – serum amylase most commonly used, usually elevated w/in 24 hrs of symptoms – amylase is NOT specific for pancreatitis -> may be high with cholecystitis, SBO, ischemic bowel, appendicitis and PUD – degree of elevation does NOT correlate w/ severity of disease Pancreatitis: Diagnosis • CT scan most sensitive • Pancreatic changes – parenchymal enlargement and edema – necrosis • Peri-pancreatic changes – blurred fat planes – thickened fascial planes – fluid collections • Non-specific findings – pleural effusion, ascites – mesenteric edema, ileus Pancreatitis: How Severe? • Multiple scoring and grading systems aimed at predicting outcome – Ranson criteria most famous, predicts mortality – Imrie, Kummerle, Bank classifications – Acute Physiology and Chronic Health Evaluation (APACHE II) illness grading system – Simplified Acute Physiology Score (SAPS II) -> score correlates w/ risk MSOF, mortality • A comparative evaluation of these systems failed to demonstrate any significant differences in overall accuracy Pancreatitis: How Severe? Non-gallstone associated pancreatitis: Age > 55 yrs Hct fall > 10% WBC > 16,000 cells/mm3 BUN elevation > 5 mg/dL Blood glucose > 200 mg/dL Serum calcium < 8 mg/dL Serum LDH > 350 IU/L Arterial pO2 < 60 mm Hg AST > 250 U/dL Base deficit > 4 mEq/L Estimated fluid sequestration > 6L Gallstone associated pancreatitis: Age > 70 yrs Hct fall > 10% WBC > 18,000 cells/mm3 BUN elevation > 2 mg/dL Blood glucose > 200 mg/dL Serum calcium < 8 mg/dL Serum LDH > 400 IU/L Arterial pO2 < 60 mm Hg AST > 250 U/dL Base deficit > 5 mEq/L Estimated fluid sequestration > 6L . Pancreatitis: How Severe? •Patients w/ < 3 Ranson criteria have no mortality •50 % of patients w/ 3-4 Ranson indicators require ICU care •Patients w/ meeting 7 or more Ranson criteria have very high mortality Number % requiring ICU % mortality 0-2 0% 0% 3-4 50% 15% 5-6 100% 50% >6 100% >50% Pancreatitis: How Severe? • Serum markers – 2 studies assessed CRP and LDH -> discrimination b/w mild and severe acute pancreatitis possible in 84% (CRP > 120 mg/dL, LDH > 270 mg/dL) – IL-6 levels increase 24-36 hours earlier than CRP • during 1st 24 hours after onset of disease, IL-6 levels had sensitivity of 100% and specificity of 86% in predicting the severity of acute pancreatitis • CT scan to identify pancreatic necrosis – defined by non-enhancement of gland as defined by Hounsfield units and/or pancreas to aorta ratio Pancreatitis: Timing of Feeding • Randomized trials of NGT, somatostatin, anticholinergics and antacids have FAILED to demonstrate any difference in duration of illness or complication rate • Concept of “pancreatic rest” has historically led to recommendation of NPO – if eating provokes pain or is not tolerated, then keep NPO and consider parenteral nutrition – in biliary pancreatitis, eating may provoke another episode -> recommend NPO or clears at most until OR Pancreatitis: Timing of Surgery • When to operate in gallstone pancreatitis? – prospective study of patients w/ gallstone pancreatitis • patients randomized to early operation (w/in 24 hrs) vs. late operation (after normalization of enzymes and CT) • no difference found b/w the groups in terms of length of stay, morbidity, or mortality – several retrospective studies confirm that timing of surgery does not affect outcome • Operation should include IOC – data supports using ERCP only for failure to clear CBD during operation rather than as a pre-operative tool Pancreatitis: Is Necrosis Infected? • Infected pancreatic necrosis is most reliably determined by CT- or USG-guided FNA with Gram staining and culture of the aspirate – Gram stain has proven a reliable early indicator of pancreatic infection w/ positive Gram stain almost always followed by positive culture • CT scan w/ air bubbles around necrosis is also diagnostic • No good data to compare routine vs. selective guidedFNA in patients w/ pancreatic necrosis – most authors reserve FNA for patients w/ clinical signs of infection – others advocate routine FNA in patients w/ complicated disease as infection may be manifested only by low grade temp Pancreatitis: Is Necrosis Infected? • Demonstrated risk factors for infection include extent of necrosis, severity of pancreatitis, and duration of disease – recent study found infection in 31% of 226 patients with documented pancreatic necrosis • highest rate of infection was found in patients with > 50% necrosis (42% infection) – risk of infection increases during course of disease, jumping from 23 % to 36% to 71% in 1st 3 weeks – infection increases w/ Ranson’s score (0-1=5% vs. >5= 58%) Pancreatitis: Sterile Necrosis • Several studies in the past decade have demonstrated that sterile pancreatic necrosis can be managed non-operatively without mortality – one study employed selective guided-FNA in patients w/ documented necrosis who remained persistently febrile or developed new fever later in hospital course – results contradicted belief that necrosis w/ organ failure was an absolute indication for surgery • Conversely, multiple publications confirm that debridement of sterile pancreatic necrosis does NOT improve the clinical course these patients Pancreatitis: Antibiotics • Antibiotic prophylaxis in sterile pancreatic necrosis remains an area of some controversy – based on belief that pancreatic tissue levels of abx can prevent colonization of pancreas after gut translocation – animal studies supported this concept – flawed 1970s study w/ ampicillin showed no difference – 7 clinical trials in last decade • • • • decreased mortality w/ cefuroxime decreased rate pancreatic infection and MSOF w/ imipenem meropenem = imipenem no benefit w/ ofloxacin/metronidazole Pancreatitis: Antibiotics • Recent meta-analysis showed positive benefit of antibiotic in reducing mortality – limited to patients w/ severe pancreatitis who received broad-spectrum abx able to achieve pancreatic tissue levels • Cochrane Database review of randomized trials (2003) – evidence that prophylactic IV antibiotic therapy for 1014 days decreases both risk of superinfection and mortality in patients with severe pancreatitis w/ proven pancreatic necrosis Pancreatitis: Antibiotics • Conclusions – clinical studies have demonstrated that use of prophylactic IV antibiotics in pancreatic necrosis decreases both infection of the necrosis and mortality – advocates favor imipenem and meropenem for their penetration into pancreatic tissue – duration of therapy remains debatable – Powell et al argued that sample size of 322 patients would be required to detect 50% reduction in infection • larger study would be needed to detect reduction in mortality – selective gut decontamination may be alternative Pancreatitis: Infected Necrosis • Literature supports surgical debridement of devitalized tissue and drainage of infected collections for any patient w/ infected necrosis – inadequate data concerning IR techniques as an alternative to surgery – laparoscopic techniques has been reported but there are no trials comparing laparoscopic vs. open approaches to operative debridement Gallstone-induced pancreatitis in 27 year-old woman Transverse CT scan obtained with intravenous and oral contrast material reveals a large, edematous, homogeneously attenuating (73-HU) pancreas (1) and peripancreatic inflammatory changes (white arrows). Although the attenuation values are low, there is no pancreatic necrosis. Calcified gallstones are seen in gallbladder (black arrow). 2 = liver (140 HU). 47-year-old man with severe pancreatitis Fluid collection replacing pancreatic body and tail 57-year-old man with acute necrotizing pancreatitis and severe back pain Large region of unenhancement (necrosis) involving most of body and tail of pancreas. Inflammatory fluid is present in anterior pararenal space. Note ascites around liver. 50 year-old woman with acute pancreatitis (1st view) Transverse CT scans obtained with intravenous and oral contrast material reveal an encapsulated fluid collection associated with liquefied necrosis (large straight arrows) in the body of the pancreas. The head, part of the body, and the tail of the pancreas are still enhancing (small straight arrows). N = liquefied gland necrosis, S = stomach. 50 year-old woman with acute pancreatitis (2nd view) Transverse CT scans obtained with intravenous and oral contrast material. The head, part of the body, and the tail of the pancreas are still enhancing (straight arrows). Residual fluid collections and areas of soft-tissue attenuation (curved arrow) consistent with fat necrosis are seen adjacent to the pancreas. f = fluid, N = liquefied gland necrosis. 28 year-old man with pseudocyst Image demonstrates a pseudocyst (arrow) in the tail of the pancreas surrounded by a thick enhancing wall. The lesion appears heterogeneous with central areas of higher attenuation, which is suggestive of fresh hemorrhage. Note infiltration (arrowheads) of the peripancreatic fat. 44 year-old man with acute abdominal pain hemorrhagic pseudocyst Axial CT scan obtained with intravenous contrast material demonstrates calcifications from chronic pancreatitis in the head of the pancreas. A high-attenuation focus of blood (arrow) is seen within the low-attenuation pseudocyst, a finding that is consistent with hemorrhage. Pancreatic abscess containing gas in 54-year-old man Large fluid collection containing gas bubbles in pancreatic bed due to abscess complicating acute pancreatitis. Note infiltration of peripancreatic fat and calcified gallstones. 70 year-old woman with hemorrhagic pancreatitis CT scan demonstrates hemorrhagic pancreatitis as a heterogeneous mass in the area of the pancreatic bed (*). Arrow indicates active extravasation (hemorrhage). Pancreatitis Protocol PANCREATITIS (based on hx, labs and PE) admit, NPO, IVF, scoring system, +/- CT scan mild symptoms +/- CT w/out necrosis no gallstones OR for lap chole w/ IOC selective guided-FNA (-) FNA identify etiology failure to clear CBD (+) FNA yes rpt CT signs of sepsis ? yes no ERCP CT w/ infected necrosis IV abx USG gallstones CT w/ necrosis early feeds, supportive care intensive critical care OR for debridement SBO: Definitions • Complete SBO – no egress of intestinal contents past point of obstruction – clinically -> no flatus or BM for 12 hours – radiographically -> no air in the colon • Partial SBO – narrowing of lumen w/out complete obstruction – may be chronic or intermittent problem, often presenting as pain – 50- 80% will resolve w/ non-operative management SBO: Definitions • Open SBO – obstructed at one end, transmitting increased intraluminal pressure proximally – may be relieved by vomiting or NGT • Closed loop SBO – bowel is obstructed at 2 points, cannot decompress – distention causes rapid rise in intraluminal pressure -> faster ischemia and perforation – may be characterized by severe pain w/out emesis SBO: Definitions • Simple SBO – blood supply to bowel is NOT compromised • Strangulated SBO – obstruction has embarrassed blood supply to small bowel • external compression (hernia) • twisted mesentery (volvulus) • increased intraluminal pressure – simple SBO may become strangulated w/ time • risk greatest in closed loop, incarcerated hernia, complete SBO SBO: Presentation • Symptoms of pain, nausea, emesis, obstipation – pain initially diffuse colic -> severe, constant if progress to ischemia – may pass flatus +/- stool up to 48 hrs after obstruction • Exam – abdominal distention, previous scars, hernias • Tests – dehydration (elevated BUN/Cr), electrolyte imbalance – AXR w/ dilated loops SB, air-fluid levels – CT w/ dilated loops (air OR fluid), poss transition SBO: Presentation AXR CT Scan SBO: Etiology • adhesions • Crohn’s disease • incarcerated hernia • radiation enteritis • early post-operative • gallstone ileus • malignancy • intussusception • combination • foreign body SBO: Adhesions • Most frequent cause of SBO in North America, accounting for 50-70% of all SBO – post-surgical adhesions – congenital adhesions – adhesions secondary to infection/inflammation • ~15% of patients who undergo abdominal surgery will have an episode of SBO – more common after colon, appy, GYN surgery – 10-30% of patients will have recurrence SBO: Incarcerated Hernia • Accounts for approximately 25 % of SBO – 50% inguinal, 25% femoral – 20% ventral, 5% other (obturator, Speigelian, etc.) • Associated w/ higher incidence of strangulation and morbidity – review of 405 pts w/ SBO -> 74% w/ adhesions (9% were strangulated) vs. 8% incarcerated hernia (33% strangulated) – review 189 pts > 65 w/ incarcerated hernia • 48% strangulated, 19% gangrenous requiring resection SBO: Early Post-Operative • Initial demonstration of bowel function -> then development of obstructive symptoms w/in 4-8 weeks of surgery – attributed to filmy, soft adhesions which regress spontaneously – bowel ischemia uncommon – 80-90% patients resolve w/ non-operative management – 2/3 will resolve w/in 7 days SBO: Strangulation • Strangulation leads to bowel infarction and perforation – associated w/ increased mortality -> 5-30% vs. 1% in simple SBO • Signs and symptoms – – – – continuous pain fever, tachycardia -> sepsis peritonitis elevated WBC, art lactate, amylase SBO: Goals of Treatment • Operate on irreversible SBO before strangulation – prompt operative intervention to reduce need for resection and morbidity • Avoid additional abdominal surgery on patients who would resolve w/ non-operative management – limit stimulus for future episodes of SBO • Difficulty lies in determining who needs an operation and when SBO: Bowel Compromise? • Multiple studies have demonstrated that there is NO RELIABLE INDICATOR of strangulation in SBO • Multi-center study of 639 pts w/ SBO – evaluated for continuous pain, fever, elevated WBC, palpable mass, peritonitis – 77 % pts w/ at least one sign had NO strangulation – 9.8% of pts found to have strangulation had NONE of these signs • Retrospective study found SIRS to be the only reliable sign of bowel strangulation (too late!) SBO: Partial or Complete? • CT w/ PO contrast not ideal due to large volume • Gastrograffin contrast studies can delineate partial from complete SBO – hyperosmolar contrast draws fluid into proximal bowel to dilute contents – safer than barium in cases of perforation • Study patients by AXR 24 hours after contrast – contrast progressed to R colon = partial – contrast remained in small bowel = complete SBO: Partial or Complete? • Choi et al looked at 121 pts w/ simple SBO – 48 hrs NGT decompression – if improved, continued observation – no improvement -> OR vs. gastrograffin study • 16 pts to OR • 19 pts had GG study w/ AXR after 24 hrs • 14 had partial SBO, all resolved (avg 41 hrs) • 5 had complete SBO -> to OR – no strangulation, no bowel resection SBO: Partial or Complete? • Onoue et al looked at 102 pts w/ simple SBO – GG contrast 1st 24 hrs -> AXR w/in subsequent 24 hrs – 92 pts w/ partial SBO -> clears • 2 pts later required OR for strangulation • Biondo et al randomized 83 pts w/ simple SBO – control rx NGT 4-5 days -> 8 to OR (2 SB resections) – GG study ER, AXR 24 hrs -> 39 partial SBOs improved, 5 complete SBO to OR (1 SB resection) • Studies indicate that GG study is reasonable protocol to distinguish complete vs. partial SBO SBO: Laparoscopy • Laparoscopic adhesiolysis 1st described by Bastug et al in 1991 – since then, various case reports, series, and retrospective reviews attesting to success of approach • Laparoscopy shown to decrease incidence, severity, and extent of post-operative adhesions when compared to open surgery • NO prospective, randomized trials comparing open and laparoscopic lysis of adhesions – indications and outcomes not well established SBO: Laparoscopy • Review of selected series – conversion: 7- 43% -> dense adhesions, iatrogenic perforation, bowel necrosis, inability to visualize point of obstruction, neoplasm – iatrogenic perforation: 3-18% – mortality: 0-3% – reduced LOS, incidence of post-op ileus • Few established selection criteria – advanced laparoscopic surgeon – bowel diameter < 4 cm, NGT decompression – fewer abdominal operations, partial or chronic SBO Meckel’s Diverticulum Causing SBO Meckel’s Diverticulum Causing SBO 50-year-old woman with strangulating small-bowel obstruction and infarction. Contrast-enhanced CT scan shows dilated and fluid-filled bowel loops in right flank (i). Small amount of fluid is present in mesentery (m). 50-year-old woman with strangulating small-bowel obstruction and infarction. Contrast-enhanced CT scan slightly more caudal reveals that wall of ischemic dilated loops is not clearly visible (white arrowheads), and proximal collapsed loops enhance normally (black arrowheads). Patient underwent surgery 24 hr later; she had complete volvulus of distal meter of small bowel caused by tight adhesive band. One meter of necrotic small bowel was resected 54-year-old man with history of appendectomy, aortic surgery, and previous laparotomy for adhesive bands. Unenhanced CT scan shows dilated and fluid-filled jejunal loops (j). Veins in adjacent mesentery are enlarged (arrowheads). 54-year-old man with history of appendectomy, aortic surgery, and previous laparotomy for adhesive bands. Unenhanced CT scan reveals fluid in mesentery around congested veins (m). Note pseudothickening of bowel wall (arrowheads) caused by transverse scanning of Kerckring's folds. Gas bubbles in intestinal lumen (arrow) must not be confused with pneumatosis. Also note large amount of fluid in pelvis. Patient was immediately treated by nasogastric suction and fully recovered without surgery 85-year-old woman with reversible ischemia. Contrast-enhanced CT scan shows signs of mechanical obstruction of small bowel with dilated and fluid-filled loops in left fossa iliaca (i). Note fluid in mesentery (m) and congestion of small mesenteric veins (arrowheads). Wall of segment of small bowel is barely visible (arrows). Small gas bubble is present in unenhanced loop. Patient underwent surgery same day and had surgical evidence of ischemic bowel due to secondary volvulus. After devolvulation, ischemic bowel regained normal coloration and resection was not necessary. Patient left hospital 7 days after admission. 67-year-old woman with thrombosis of superior mesenteric vein who presented with clinical signs of intestinal obstruction. Contrast-enhanced CT scan reveals thrombus (arrowhead) in superior mesenteric vein. Second portion of duodenum (d) and proximal jejunum (i) are dilated and fluid-filled 67-year-old woman with thrombosis of superior mesenteric vein who presented with clinical signs of intestinal obstruction. Contrast-enhanced CT scan more caudal shows absence of enhancement (white arrowheads) of dilated jejunal loop, and more proximal loop enhances normally (black arrowheads). Note that nonenhancing loop has no evidence of wall thickening. 67-year-old woman with thrombosis of superior mesenteric vein who presented with clinical signs of intestinal obstruction. Contrast-enhanced CT scan more caudal than B. Jejunal loops have thickened wall with reduced enhancement (arrowheads). Mesentery (m) is hazy. Patient was treated medically with anticoagulant therapy and had uneventful evolution. Months later she developed fibrotic stricture but did not undergo surgery 65-year-old man with history of allergy to iodine contrast agent. Unenhanced CT scan shows dilated and fluid-filled small-bowel loops (i) occupying left flank. Mesentery (m) is hazy because of presence of triangular-shaped fluid adjacent to dilated loops 65-year-old man with history of allergy to iodine contrast agent. Unenhanced CT scan 3 cm more cephalad than A reveals presence of congested mesenteric veins (arrowheads). Surgery performed 6 hr later confirmed diagnosis of strangulation. It was caused by internal hernia, and 1.20 m of necrotic bowel was resected SBO Protocol SBO (based on hx, labs, PE, flat + upright AXR) NPO, NGT, IVF, Foley in ER CT w/out transition or closed loop non-contrast CT, admit CT w/ closed loop incarcerated hernia peritonitis signs of sepsis 24 hrs w/ NGT, IVF deterioration improve no change D/C NGT, clears well adv diet 120 cc GG, AXR at 24 hrs contrast R colon contrast in SB only OR fail
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