GI ANOMALIES
| Acid Control in the Hospitalized Patient: Simple Questions, Complex Answer — Robert G. Martindale, MD, PhD,
Professor of Surgery and Medical Director for Hospital Nutrition Services, Oregon Health and Science University, Portland
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| Who needs acid control: in hospital — for prevention of stress-related mucosal disease, peptic ulcer disease
(PUD), gastroesophageal reflux disease (GERD), aspiration, and in perioperative period; therapeutic decisions —
who needs it, which agent, which route, and when to discontinue
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| Stress-related mucosal disease: incidence in intensive care unit (ICU) — endoscopically, 75% to 100% have
some evidence of mucosal disease; clinically significant bleeding (enough to show change in hematocrit or hemodynamics)
5% to 25%; clinically significant bleeding requiring transfusion, ≈1%; mortality rate rises significantly
with stress ulcer bleeding in ICU; patients do not die from bleeding but from disease that causes stress mucosal
problems; major bleeding increases mortality and prolongs hospital stay by ≈19 days; increased cost; mechanism
— splanchnic hypoperfusion; restoring hemodynamics key; acid level or pH goal to prevent disease — pepsin inactivated
at pH 4.5; at pH 5.0, 99.5% of acid neutralized; goal pH of 5; risk factors for bleeding in ICU — respiratory
failure on ventilator and coagulopathy; Joint Commission on Accreditation of Healthcare Organizations
(JCAHO) using stress prophylaxis as indicator of problem in hospital; agents — sucralfate, antacids, proton pump
inhibitors (PPIs), histamine H2 receptor antagonists (H2 RAs); gastroprotective agents (antacids, sucralfate) of historic
interest; at present, 3 intravenous (IV) PPIs available
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| Stress ulcer prophylaxis: continuous infusion of H2 RAs not used for prophylaxis, although approved by Food
and Drug Administration (FDA); not effective in ICU; study (Cook 2002) — 1200 mechanically ventilated patients;
no increase in incidence of pneumonia in those treated with H2 RAs; advantages of H2 RAs — inexpensive;
easy to administer; pH dependent; disadvantages of H2 RAs —confusion; thrombocytopenia; drug interactions;
tolerance (tachyphylaxis within 72 hr); study comparing continuous infusion of H2 RA to PPI found that within 3
days, median pH drops considerably with H2 RA, whereas with PPI, pH same or gets better; advantages of PPIs
— profound acid suppression; pH dependent; no tolerance; multiple forms available; disadvantages of PPIs —
some drug interactions; few adverse reactions; different modes of delivery; in npo patient — ≈15% of proton
pumps active at any given time; by giving continuous infusion, newly activated pumps taken out of system; dosing
with H2 RA vs PPI — slightly better prophylaxis with PPIs; best data with continuous infusion of H2 RA
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 | Who should receive prophylaxis: high-risk patients, ie, those on ventilator, with coagulopathy, in ICU, with 1 or 2
organ failures, with hemodynamic instability; number needed to treat (NNT) to prevent bleeding 1 in 30; general
principles — problem in stress-related mucosal disease hypotension and poor perfusion of gastrointestinal (GI)
tract (visceral hypoperfusion); PPIs better than H2 RAs for consistency of pH, lack of tolerance, no dose adjustment
for renal clearance, side-effect profile, and fewer drug interactions; PPIs used 55% of time for in-hospital
prophylaxis
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| Peptic ulcer disease: mortality 5% to 12% (depending on comorbidities); rebleeding key; 2 major groups include
those who present with bleeding and those who bleed while in ICU; in those who present with GI bleeding, 95% of
bleeding related to nonsteroidal anti-inflammatory drug (NSAID) or Helicobacter pylori (mortality 7%-10%); acute
bleeding — initial management blood typing and cross-matching; IV access; determination of risk and therapeutic
decisions based on endoscopic findings; in Canada, patients who present to emergency department (ED) in middle of
night with bleeding started on octreotide and IV PPIs, then endoscopy done in morning; treat H pylori; if bleeding
does not stop, alter acute management; rebleeding — injection and cautery; clot stability key; for clot stability, need
pH >6; H2RAs have no efficacy in preventing rebleeding, no significant reduction in blood transfusions or need for
surgery, no overall survival benefit, and do not achieve desired pH level; need to use PPIs (delivered as bolus); for
omeprazole and pantoprazole, need 80 mg IV push over 2 min, then infusion; for lansoprazole (Prevacid), 60 mg IV
push, then 6 mg/hr; Cochrane analysis — 21 randomized clinical trials of PPIs in peptic ulcer rebleeding; significant
decrease in rebleeding and surgery but no change in mortality; study in 2006 — lansoprazole at sustained intragastric
pH; given as IV bolus; various PPIs compared; rapidly dissolving oral tablet used as follow-up therapy, with pH kept
>6; with combined therapy (endoscopic and IV omeprazole), within 30 days of rebleeding, chance of rebleeding
≈1%, compared to 11% with IV omeprazole alone; study — 1200 patients; pantoprazole vs ranitidine for prevention
of ulcer rebleeding; marked difference seen with very aggressive ulcers; NNT for IV PPIs to prevent rebleeding 5 or
6; interventional radiology to prevent rebleeding — getting better at selective cannulation of smaller vessels; angiography
and embolization reasonable tools; if necessary to perform surgery —continue PPIs; rarely need to perform
surgery for major bleeding; decreased rebleeding rate (and need to perform surgery) due to use of IV PPIs;
cost-effectiveness — no longer issue
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| Proton pump inhibitors: potential benefits — have antiapoptotic effect and serve as free radical scavengers in ICU
(hypotension and hypoperfusion of stomach); cause increase in hemoxygenase 1 (heat shock protein), induced in
gastric mucosa to protect from subsequent stresses; cause calcium-dependent vasorelaxation independent of nitric
oxide–arginine cascade (vasodilatation of gastric mucosa); cause increased appetite in patients recovering from
major illness; excellent side-effect profile; disadvantages of PPIs —metabolized by cytochrome P450 3A4 and cytochrome
P450 2C19; data show esomeprazole and omeprazole inhibit cytochrome P450 2C19 (impairing metabolism
of diazepam, ventolin, and warfarin); association with community-acquired pneumonia and Clostridium
difficile; after major liver resection, IV PPIs decrease hepatocyte regeneration; areas of future study — if patient on
self-prescribed PPIs and hospital protocol calls for H2 RA prophylaxis, be aware of rebound effect (patient should
be maintained on PPI); Asian population different in their cytochrome P450 2C19 metabolism (higher rate of metabolism),
so drug may have different effect
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| SURGICAL MANAGEMENT OF DIVERTICULAR DISEASE — John C. Russell, MD, Professor and Interim
Chair, Department of Surgery, University of New Mexico School of Medicine, Albuquerque
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| Anatomy: diverticulosis found throughout colon, most commonly in sigmoid colon; symptomatic diverticulitis usually
in sigmoid colon; cecal diverticulitis occurs in patients in their 20s, 30s, and 40s (more common in Asian and
West Indian populations); bleeding diverticular disease occurs anywhere in colon (some series state more common
on right side); false diverticulum — does not include all layers of bowel wall (mucosa with some serosa, but no
muscle layer); reason related to blood supply to colon; where blood supply perforates mucosa, small defect in muscle
wall present (area of weakness that subsequently forms pseudodiverticuli); complications of diverticulitis —
free perforation, perforation into nearby viscus (eg, small bowel, bladder, uterus, vaginal cuff; occasionally, direct
fistulization to abdominal wall); after diverticulitis, areas of stricture may occur (indistinguishable from cancer)
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| Pathophysiology of diverticulitis: acquired disease; believed to be consequence of Western diet (not enough fluids
and bulk; constipation); associated with development of chronic hypertension (increased intraluminal pressure
and acquired muscle hypertrophy); also underlying motility disorder; segmentation of bowel and increased pressure;
over time, weak points in muscle wall where vessels perforate develop pseudodiverticuli
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| Indications for surgery: perforation, bleeding, obstruction, failure to respond to medical therapy (malignant diverticulitis),
and recurrent attacks
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| Current management: 3-stage procedure rarely done; more aggressive resections (longer length of resection to
remove all hypertrophied muscle); more accurate bleeding localization; use of on-table colonic lavage or bowel
preparation; use of computed tomography (CT) for diagnosis (shows inflammation); percutaneous drainage of abscesses;
laparoscopic or hand-assisted laparoscopic surgery
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| Optimal management of perforated sigmoid diverticulitis: Hinchey classification; stage 1 — pericolic abscess
confined by mesentery of colon; stage 2 — pelvic abscess resulting from local perforation of pericolic abscess;
stage 3 — generalized peritonitis (no communication with lumen of colon); stage 4 — fecal peritonitis;
stage 2a — local abscess amenable to percutaneous drainage; stage 2b — abscess walled off but perforated into
viscus, eg, colovesical fistula
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| Management options: 3-stage procedure — diverting colostomy (transverse) or ileostomy; resection of sigmoid colon
with primary anastomosis; closure of diverting colostomy or ileostomy; resection of sigmoid colon with primary
anastomosis; closure of diverting colostomy or ileostomy; 2-stage procedure A — resection of sigmoid colon, end-
sigmoid colostomy, and “turn-in” of distal colon (Hartmann procedure) or if long distal segment present, mucus fistula;
second step (3 to 6 mo later) closure of end-sigmoid colostomy; 2-stage procedure B — resection of sigmoid
colon with primary anastomosis (with or without on-table bowel preparation), with proximal diverting colostomy or
ileostomy; second step closure of diverting colostomy or ileostomy; one-stage procedure — sigmoid colon resection
(with or without on-table bowel preparation) and primary colonic anastomosis
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| Technique of on-table bowel preparation: mobilize segment of colon for resection; large Foley catheter inserted
into cecum (base of appendix) or terminal ileum; sterile corrugated plastic tubing inserted just above proximal
margin of resection of colon and brought off operating room field into disposable plastic container; 3 to 6 L of
warm saline lavage or until clear
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| Current standard of care for perforated sigmoid diverticulitis: 3-stage procedure primarily of historical interest;
2-stage Hartmann procedure most widely used; 1-stage procedure widely advocated but not widely accepted
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| Primary anastomosis vs Hartmann’s procedure: pros —one operation rather than 2; total morbidity and mortality
same or lower than for 2-stage procedure; cons — too much surgery for sick patient; risks of anastomosis in
unfavorable setting; which procedure to choose — factors in decision include status of patient, local anatomy, and
literature
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| Practice of evidence-based medicine (EBM): in making evidence-based decisions, consider research evidence,
clinical expertise, and patient preferences
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| Ask well-built clinical question: first step in EBM; 4 components (PICO) of well-built question — specify patient;
identify intervention; comparison (identify what intervention compared to [usually Hartmann procedure]); identify
outcome of interest (survival without major morbidity)
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| Search for best evidence to answer question: “any empirical observation about apparent relation between events constitutes
potential evidence”; hierarchy of evidence — systematic reviews of randomized controlled trials (RCTs) highest
level; single randomized controlled trial with good result in consistent population; systematic review of cohort studies;
individual cohort study; observational studies tend to overestimate treatment results; sometimes unable to get RCT, but if
treatment effect uniformly consistent and overwhelming, sufficient to make decision; searching for evidence — Cochrane
database; database of abstracts of reviews of effectiveness (DARE) also maintained by Cochrane; PubMed
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| Critically appraise evidence: on issue of primary anastomosis vs Hartmann procedure for perforated sigmoid diverticulitis,
no systematic review of RCTs and no individual RCT; systematic review of cohort studies — Salem
and Flum reviewed >90 studies between 1957 and 2003; conclusion resection and primary anastomosis safe procedure
in certain patients with peritonitis; individual cohort study — Schilling concluded resection and primary anastomosis
(with on-table bowel preparation) safe lower-cost procedure, even for patients with fecal peritonitis
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| Apply evidence to patient: summary — good-risk patients tolerate almost anything; for Hinchey stages 1 and 2, resection
and primary anastomosis generally safe; for Hinchey stage 3 (purulent peritonitis) in good-risk patients, resection
and primary anastomosis probably safe; for Hinchey stage 4 (feculent peritonitis), 2-stage Hartmann
procedure better choice; unknown whether proximal diversion improves outcomes; need more data from prospective
RCTs
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| Management of colovesical fistula: special case of Hinchey stage 2; fistula from sigmoid colon (distal colon often
normal); primary resection with anastomosis (with or without loop colostomy or loop ileostomy) good choice;
put omentum between colon suture line and bladder; do minimal, if any, resection of bladder; Foley catheter for 8
to 10 days postoperatively; successful laparoscopic repair reported
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| Is there still role for subtotal colectomy for massive colonic diverticular hemorrhage? yes; therapeutic
angiography has dramatically reduced need for surgery; if localized but not controlled arteriographically, segmental
colectomy feasible; if not localized and small bowel and rectal sources excluded, subtotal colectomy indicated;
trying to find colonic source intraoperatively futile exercise; segmental colectomy for nonlocalized bleeding has
high rate of recurrent bleeding and significant mortality
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| When to operate electively: no indication for prophylactic colectomy for asymptomatic diverticulosis; usually
operate after second attack; operate after first attack if patient young (<40 yr of age) or if immunocompromised
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| Necessity of bowel preparations for colon surgery: European studies state that can perform elective colon
surgery with antibiotic coverage without any bowel preparation; experience with traumatic colon injuries suggests
that possible in selected patients; speaker recommends if unable to perform bowel preparation preoperatively, can
be done intraoperatively; intraoperative colonic lavage simple, safe, and effective
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Suggested Reading
Brett S: Science review: The use of proton pump inhibitors fo.gastric acid suppression in critical illness. Crit Care
9:45, 2005; Carballo F: Efficiency of potent gastric acid inhibition. Drugs 65 Suppl 1:105, 2005; Cash BD: Evidence-based
medicine as it applies to acid suppression in the hospitalized patient. Crit Care Med 30:S373, 2002;
Cook DJ et al: Toward understanding evidence uptake: semirecumbency for pneumonia prevention. Crit Care Med
30:1472, 2002; Floch MH et al: Management of diverticular disease is changing. World J Gastroenterol 12:3225,
2006; Frieri G et al: Management of colonic diverticular disease. Digestion 73 Suppl 1:58, 2006; Garcea G et al:
Diagnosis and management of colovesical fistulae; six-year experience of 90 consecutive cases. Colorectal Dis
8:347, 2006; Gisbert JP: Potent gastric acid inhibition in Helicobacter pylori eradication. Drugs 65 Suppl 1:83,
2005; Gomollon F et al: Optimising acid inhibition treatment. Drugs 65 Suppl 1:25, 2005; Julapalli VR et al:
Appropriate use of intravenous proton pump inhibitors in the management of bleeding peptic ulcer. Dig Dis Sci
50:1185, 2005; Keenan SP et al: Ventilator-associated pneumonia. Prevention, diagnosis, and therapy. Crit Care
Clin 18:107, 2002; Martindale RG: Contemporary strategies for the prevention of stress-related mucosal bleeding.
Am J Health Syst Pharm 62:S11, 2005; Nguyen SQ et al: Laparoscopic surgery for diverticular disease complicated
by fistulae. JSLS 10:166, 2006; Parra-Blanco A: Colonic diverticular disease: pathophysiology and clinical
picture. Digestion 73 Suppl 1:47, 2006; Pisegna JR: Treating patients with acute gastrointestinal bleeding or rebleeding.
Pharmacotherapy 23:81S, 2003; Qadeer MA et al: Hospital-acquired gastrointestinal bleeding outside
the critical care unit: risk factors, role of acid suppression, and endoscopy findings. J Hosp Med 1:13, 2006; Sabesin
SM: Goals of therapy: aggressive or moderate acid suppression? Clin Ther 8 Suppl A:41, 1986; Saultz A et al:
What GI stress ulcer prophylaxis should we provide hospitalized patients? J Fam Pract 56:51, 2007; Scarpignato
C et al: Acid suppression therapy: where do we go from here? Dig Dis 24:11, 2006; Tsuji S et al: A new-generation
H2 receptor antagonist: quicker and stronger acid inhibition than proton pump inhibitors in the clinical setting? J
Gastroenterol 40:549, 2005; Welage LS: Overview of pharmacologic agents for acid suppression in critically ill patients.
Am J Health Syst Pharm 62:S4, 2005; Yearsley KA et al: Proton pump inhibitor therapy is a risk factor for
Clostridium difficile-associated diarrhoea. Aliment Pharmacol Ther 24:613, 2006
Educational Objectives
| The goal of this program is to improve acid control in the hospitalized patient and surgical management of diverticular
disease. After hearing and assimilating this program, the clinician will be better able to:
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| 1. Identify which patients need acid control.
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| 2. Discuss the advantages and disadvantages of H2 receptor antagonists and proton pump inhibitors.
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| 3. Describe the anatomy, pathophysiology, and indications for surgery of diverticular disease.
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| 4. Review the surgical management options for sigmoid diverticulitis.
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| 5. Apply the process of evidence-based medicine in practice.
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Disclosure
In adherence to ACCME guidelines, the Audio-Digest Foundation requests all lecturers to disclose any significant financial
relationship with the manufacturer or provider of any commercial product or service discussed. For this issue,
the faculty reported nothing to disclose.
Acknowledgements
Dr. Martindale was recorded at Medical and Surgical Approaches to GI Disorders, held July 10-14, 2006, in Kiawah
Island, SC, and sponsored by the Medical College of Georgia, Division of Continuing Medical Education and School
of Medicine. Dr. Russell was recorded at Current Concepts in General Surgery and Trauma, held September 6-8,
2006, in Albuquerque, NM, and sponsored by the University of New Mexico Health Sciences Center, Department of
Surgery and Office of Continuing Medical Education. The Audio-Digest Foundation thanks the speakers and the
sponsors for their cooperation in the production of this program.
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