• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of jmlaJournal informationSubscribeSubmissions on the Publisher web siteCurrent issue of JMLA in PMCAlso see BMLA journal in PMC
J Med Libr Assoc. Jan 2007; 95(1): 3–8.
PMCID: PMC1773044

Utilizing case reports to build awareness of rare complications in critical care

INTRODUCTION

As the second installment in the JMLA's new case study column, this issue's case considers the role of the librarian in addressing a complex clinical question that requires extracting relevant evidence when the literature is almost exclusively limited to case reports. This case study also tackles the challenge of identifying an effective strategy for organizing and presenting case report details to answer a clinical question. The commentary and discussion of results for this case were updated on September 13, 2006. We invite your commentary on this case online at <http://jmlacasestudies.blogspot.com>.

THE CASE

A 42-year-old male was admitted to the ICU following a motor vehicle collision (MVC). The patient currently has a diverting ileostomy, after losing most of the colon to ischemia secondary to blunt trauma to his abdomen during the MVC. The patient developed ventilator-associated pneumonia (VAP) several days after the operation to remove a significant amount of ischemic colon and construct the ileostomy; he was treated with a seven-day course of broad-spectrum antibiotics for the VAP.

After completing antibiotic therapy for the pneumonia, the patient developed diarrhea with high volume output from the ileostomy; despite consultation with the nutritionist and numerous interventions (e.g., administration of antidiarrheal agents) over the course of several days, the patient continues to have significant output from his ileostomy.

During morning rounds, one of the residents mentions that the team had sent a sample of the ileostomy output to be tested for Clostridium difficile. The team discusses the Clostridium difficile organism as one of the most common causes of diarrhea in the ICU, particularly in patients with a recent history of exposure to antibiotics. However, C. difficile typically involves the colon rather than the small intestine, and the current patient has loss of continuity between the small intestine and colon because of the ileostomy.

The attending physician notes that he has not heard of C. difficile infection involving the small intestine and asks you, as the team's evidence consultant, to explore whether the literature indicates that the small intestine can be involved in C. difficile infection and if such infection can develop despite loss of continuity with the colon (due to the presence of the ileostomy in this patient). Figure 1 includes further clinician commentary on the clinical significance of this question.

Figure 1
Clinician commentary

UNDERSTANDING THE CONCEPTS

The initial case in this series, published in the October 2006 issue, discussed the importance of understanding the medical concepts comprising the clinical question in selecting relevant literature. Table 1 provides brief definitions of key concepts for this question, with references providing example resources for identifying such background information.

Table thumbnail
Table 1 Brief concept definitions with references to introductory-level sources of information

EXPLORING THE LITERATURE

The selection of search terms for this question is informed by consideration of the concepts discussed in Table 1. For this search, key concepts to be represented in the search strategy include: 1) the Clostridium difficile pathogen and 2) accompanying involvement of the small bowel or presence of an ileostomy.

A search in PubMed combining these concepts might look something like: (clostridium[majr] OR clostridium infections[majr]) AND (difficile[tiab]) AND (enteritis[tiab] OR intestine, small[mh] OR ileostomy[mh] OR ileostomy[tiab]) AND humans[mh] AND eng[la].

Approximately 50 results are returned by this search. It is clear that many of the articles are not relevant to your clinical question. For example, Songer specifically addresses animals [10], while others examine related problems in infants [1112]; none of these represents your target population of adult surgical patients. Other articles focus on genetic and basic science aspects of C. difficile [1314] and can also be disregarded.

Although you have eliminated several citations based on clear cues from their title and abstract content, others will require more thorough evaluation. The Parikh citation [15] looks promising, but when you examine the text you find that it is a letter to the editor and largely summarizes two other cases published separately in the literature [1617]. A letter to the editor may occasionally point out important methodological flaws in a published piece; that does not seem to be the case for the Parikh letter, so you can safely eliminate this item.

You quickly realize that this is not a question that will be answered by clinical trials or other research methodologies: because the question does not consider an intervention or specific diagnostic strategy, a clinical trial is not suited for the topic. It also appears as though the condition is too rare to have prompted other observational work (e.g., a case control study). The available evidence for this topic is clearly limited to several relevant case reports [1626], which you select for this question. Though randomized controlled trials are often considered the “gold standard” for clinical research, case reports can be very useful in addressing a question such as this, involving a fairly rare combination of issues (C. difficile infection and involvement of the small bowel). While noting the limitations of case reports in firmly establishing associations, a number of authors emphasize the importance of such reports in summarizing issues like these that are “out of the ordinary,” providing tools for educating trainees in case-based reasoning, and prompting the generation of hypotheses for exploration in future research [2732].

In addition to the case literature, you also note an autopsy study including 100 patients, which provides C. difficile culture results from jejunal segments [33]. The positive culture results in three patients reported in this study may be worth noting, as none of the patients were diagnosed with diarrhea or other gastrointestinal symptoms before their death; this study may be useful in describing the small intestine as a possible “reservoir” for the C. difficile organism in some individuals.

During your examination of the references cited by the case reports [1626] and autopsy study [33] you have selected, you notice one additional article not included in your initial search retrieval that seems relevant to the question [34]. Retrieving the PubMed record for this article, you notice that the subject headings and the abstract do not indicate involvement of the small bowel, though one of the six cases of C. difficile infection described in the article involves a patient with an ileostomy, highlighting the importance and value of hand-searching of reference lists to complement the PubMed retrieval [3540].

SUMMARIZING THE INDIVIDUAL REFERENCES

Now that you have selected the cases that are most relevant to the patient case in question, you are met with the challenge of determining how to most effectively organize and summarize the information in a way that will make it quick and relatively easy for the clinical team to process and compare.

As you peruse each of the cases, you notice that they seem to fall into groups, including four cases with ileostomy [1719, 34]; one case with a history of total abdominal colectomy [16]; and eight other cases with small bowel involvement [2026]. Additionally, the autopsy study does not provide detailed cases but does include confirmed presence of C. difficile in culture of small bowel specimens in three patients [33].

The literature can also guide your selection of a format for summarizing these results. Reviews of reported cases often use tables to succinctly summarize relevant information from included cases [4143]. Though several of the articles you have selected include a tabular representation of cases reported in the literature [19, 21, 23], they provide only abbreviated description of the cases and their clinical courses; it is likely that these tables do not contain enough information to provide adequate representation of the case details, and none of these individual articles includes all the cases selected during the literature searching portion of this case study. The October case also employed a tabular format for summarizing the individual articles; your table for the current question will likely need to differ somewhat in formatting—the previous case's column labels (study design; patient population; methodology; outcome), while useful for summarizing clinical studies, do not lend themselves to the organization of case report details. For the current case, you will want to select column labels that provide for effective organization of the specifics of individual cases; Table 2 provides a suggested layout for case literature; an online version of the table is available in Word format, so that you may apply this template to summarizing the other cases selected for this question as a practice exercise. The columns selected to organize these cases include:

  • History, including details such as patient age, gender, comorbid diseases, past operations, any recent antibiotic use
  • Symptoms and signs presenting in the patient at the time clinicians began to suspect possible C. difficile infection or other disease process (e.g., abdominal pain, fever, diarrhea)
  • Lab(s), describing diagnostic tests employed to identify the source of patient signs and symptoms and key findings of the diagnostic interventions
  • Treatment details, including timing, dosage and duration of antibiotic therapy and any other interventions (e.g., surgical resection)
  • Outcome, summarizing final details of the patient's course such as duration of recovery and any other complications that developed.
Table thumbnail
Table 2 Summarizing the individual articles

OVERALL STATE OF THE LITERATURE

As discussed in the October case, an “executive summary” of the literature on the topic will serve as an excellent introduction and synthesis of the cases you have just incorporated into the table. Considering the key points you have uncovered in your exploration of the literature, this overall summary might include:

  • Characterization of the quality and volume of literature available on this topic
  • Overview of the kinds of cases you have selected to answer this question
  • A brief description of the autopsy study [33], which didn't provide enough case details for inclusion in the tabular summarization of cases, and its connection with the current question
  • Summary of management strategies for C. difficile small bowel infection as described in the included cases, with comment regarding whether it is similar to traditional management strategies for C. difficile colitis
  • Commentary regarding the implications of small bowel C. difficile infection, i.e., morbidity and mortality risk conferred by this type of infection.

Figure 2 provides an example of how you might frame this overall state of the literature commentary.

Figure 2
Sample statement describing the overall state of the literature

CONCLUDING REMARKS

The evidence you have presented to the clinical team makes them aware that active C. difficile infection is still a possibility in a patient with an ileostomy, and thus may be a cause of his diarrhea. In combination with their clinical expertise, the team uses this information to support the initiation of a course of metronidazole in this patient, which leads to the successful resolution of his diarrhea.

The evidence you extracted from the case literature has made the team aware of a clinical entity that is fairly rare and not well-known even among experienced clinicians; several members of the team comment that information presented in this way will be difficult to forget and will likely inform the care of future patients. As attention to detail is very important in the care of critically ill patients, the connections you have made between this patient case and the data available in the literature have promoted the effective treatment of his condition and resolution of symptoms that otherwise may have lead to significant complications.

Supplementary Material

Supplemental Table 2:

REFERENCES

  • Gibbs MA, Tayal VS. Electrolyte disturbances. In: Marx JA, ed. Rosen's emergency medicine: concepts and clinical practice. 6th ed. Philadelphia, PA: Mosby, 2006: 1933–53.
  • Donaldson RM Jr. Significance of small bowel bacteria. Am J Clin Nutr. 1968.  Sep; 21(9):1088–96. [PubMed]
  • Keighley MRB. Ostomy management. In: Zuidema GD, ed. Shackelford's surgery of the alimentary tract. 5th ed. Philadelphia, PA: W.B. Saunders, 2002:305–31.
  • Centers for Disease Control and Prevention. Clostridium difficile infections: information for healthcare providers. Atlanta, GA: The Centers, 2006. [rev. 22 Jul 2005; cited 13 Sep 2006]. <http://www.cdc.gov/ncidod/dhqp/id_CdiffFAQ_HCP.html>.
  • Clostridium difficile organism. In: MedlinePlus medical encyclopedia. [Web document]. Atlanta, GA: A.D.A.M., 2006. [rev. 3 May 2006; cited 13 Sep 2006]. <http://www.nlm.nih.gov/medlineplus/ency/imagepages/1051.htm>.
  • Centers for Disease Control and Prevention. General information about Clostridium difficile infections. [Web document]. Atlanta, GA: The Centers, 2006. [rev. 22 Jul 2005; cited 13 Sep 2006]. <http://www.cdc.gov/ncidod/dhqp/id_CdiffFAQ_general.html>.
  • Antibiotic-associated diarrhea. [Web document]. Rochester, MN: Mayo Clinic, 2006. [rev. 11 May 2006; cited 13 Sep 2006]. <http://www.mayoclinic.com/health/antibiotic-associated-diarrhea/DS00454>.
  • American Medical Association. Atlas of the body: the digestive system. [Web document]. Chicago, IL: AMA, 2006. [cited 13 Sep 2006]. <http://www.medem.com/medlb/article_detaillb.cfm?article_ID=ZZZ7C4T46JC&sub_cat=511>.
  • Ileostomy. In: Wikipedia. [Web document]. [rev. 21 Aug 2006; cited 13 Sep 2006]. <http://en.wikipedia.org/wiki/Ileostomy>.
  • Songer JG, Anderson MA. Clostridium difficile: an important pathogen of food animals. Anaerobe. 2006.  Feb; 12(1):1–4. [PubMed]
  • Buts JP, Corthier G, and Delmee M. Saccharomyces boulardii for Clostridium difficile-associated enteropathies in infants. J Pediatr Gastroenterol Nutr. 1993.  May; 16(4):419–25. [PubMed]
  • Hyams JS, Berman MM, and Helgason H. Nonantibiotic-associated enterocolitis caused by Clostridium difficile in an infant. J Pediatr. 1981.  Nov; 99(5):750–2. [PubMed]
  • Carneiro BA, Fujii J, Brito GA, Alcantara C, Oria RB, Lima AA, Obrig T, and Guerrant RL. Caspase and bid involvement in Clostridium difficile toxin A-induced apoptosis and modulation of toxin A effects by glutamine and alanyl-glutamine in vivo and in vitro. Infect Immun. 2006.  Jan; 74(1):81–7. [PMC free article] [PubMed]
  • Sambol SP, Merrigan MM, Lyerly D, Gerding DN, and Johnson S. Toxin gene analysis of a variant strain of Clostridium difficile that causes human clinical disease. Infect Immun. 2000.  Oct; 68(10):5480–7. [PMC free article] [PubMed]
  • Parikh VA, Edlund JW. Fatal Clostridium difficile enteritis after total abdominal colectomy. J Clin Gastroenterol. 1996.  Jun; 22(4):329. [PubMed]
  • Yee HF Jr, Brown RS Jr, and Ostroff JW. Fatal Clostridium difficile enteritis after total abdominal colectomy. J Clin Gastroenterol. 1996.  Jan; 22(1):45–7. [PubMed]
  • Kuntz DP, Shortsleeve MJ, Kantrowitz PA, and Gauvin GP. Clostridium difficile enteritis. A cause of intramural gas. Dig Dis Sci. 1993.  Oct; 38(10):1942–4. [PubMed]
  • Vesoulis Z, Williams G, and Matthews B. Pseudomembranous enteritis after proctocolectomy: report of a case. Dis Colon Rectum. 2000.  Apr; 43(4):551–4. [PubMed]
  • Freiler JF, Durning SJ, and Ender PT. Clostridium difficile small bowel enteritis occurring after total colectomy. Clin Infect Dis. 2001.  Oct 15; 33(8):1429–31. [PubMed]
  • Kralovich KA, Sacksner J, Karmy-Jones RA, and Eggenberger JC. Pseudomembranous colitis with associated fulminant ileitis in the defunctionalized limb of a jejunal-ileal bypass. Report of a case. Dis Colon Rectum. 1997.  May; 40(5):622–4. [PubMed]
  • Hayetian FD, Read TE, Brozovich M, Garvin RP, and Caushaj PF. Ileal perforation secondary to Clostridium difficile enteritis: report of 2 cases. Arch Surg. 2006.  Jan; 141(1):97–9. [PubMed]
  • Tjandra JJ, Street A, Thomas RJ, Gibson R, Eng P, and Cade J. Fatal Clostridium difficile infection of the small bowel after complex colorectal surgery. ANZ J Surg. 2001.  Aug; 71(8):500–3. [PubMed]
  • Jacobs A, Barnard K, Fishel R, and Gradon JD. Extracolonic manifestations of Clostridium difficile infections. Presentation of 2 cases and review of the literature. Medicine (Baltimore). 2001.  Mar; 80(2):88–101. [PubMed]
  • Tsutaoka B, Hansen J, Johnson D, and Holodniy M. Antibiotic-associated pseudomembranous enteritis due to Clostridium difficile. Clin Infect Dis. 1994.  Jun; 18(6):982–4. [PubMed]
  • Shortland JR, Spencer RC, and Williams JL. Pseudomembranous colitis associated with changes in an ileal conduit. J Clin Pathol. 1983.  Oct; 36(10):1184–7. [PMC free article] [PubMed]
  • Taylor RH, Borriello SP, and Taylor AJ. Isolation of Clostridium difficile from the small bowel. Br Med J (Clin Res Ed). 1981.  Aug 8; 283(6288):412. [PMC free article] [PubMed]
  • Vandenbroucke JP. In defense of case reports and case series. Ann Intern Med. 2001.  Feb 20; 134(4):330–4. [PubMed]
  • Kagan AR, Burchette RJ, and Iganej S. The case for case reports: avoiding statistical seduction. Am J Clin Oncol. 2006.  Aug; 29(4):325–7. [PubMed]
  • Walter G, Rey JM, and Dekker F. The humble case report. Aust N Z J Psychiatry. 2001.  Apr; 35(2):240–5. [PubMed]
  • Martyn C. Case reports, case series and systematic reviews. QJM. 2002.  Apr; 95(4):197–8. [PubMed]
  • Brighton B, Bhandari M, Tornetta P 3rd, and Felson DT. Hierarchy of evidence: from case reports to randomized controlled trials. Clin Orthop Relat Res. 2003.  Aug; (413). 19–24. [PubMed]
  • McEwen IR. Case reports: slices of real life to complement evidence. Phys Ther. 2004.  Feb; 84(2):126–7. [PubMed]
  • Testore GP, Nardi F, Babudieri S, Giuliano M, Di Rosa R, and Panichi G. Isolation of Clostridium difficile from human jejunum: identification of a reservoir for disease? J Clin Pathol. 1986.  Aug; 39(8):861–2. [PMC free article] [PubMed]
  • LaMont JT, Trnka YM. Therapeutic implications of Clostridium difficile toxin during relapse of chronic inflammatory bowel disease. Lancet. 1980.  Feb 23; 1(8165):381–3. [PubMed]
  • Hopewell S, Clarke M, Lusher A, Lefebvre C, and Westby M. A comparison of handsearching versus MEDLINE searching to identify reports of randomized controlled trials. Stat Med. 2002.  Jun 15; 21(11):1625–34. [PubMed]
  • Wilczynski NL, Haynes RB, Lavis JN, Ramkissoonsingh R, and Arnold-Oatley AE. HSR Hedges team. Optimal search strategies for detecting health services research studies in MEDLINE. CMAJ. 2004.  Nov 9; 171(10):1179–85. [PMC free article] [PubMed]
  • Helmer D, Savoie I, Green C, and Kazanjian A. Evidence-based practice: extending the search to find material for the systematic review. Bull Med Libr Assoc. 2001.  Oct; 89(4):346–52. [PMC free article] [PubMed]
  • Adams CE, Power A, Frederick K, and Lefebvre C. An investigation of the adequacy of MEDLINE searches for randomized controlled trials (RCTs) of the effects of mental health care. Psychol Med. 1994.  Aug; 24(3):741–8. [PubMed]
  • Cochrane Collaboration. Cochrane handbook for systematic reviews of interventions. [Web document]. Oxford, UK: Cochrane Collaboration, 2006. [rev. 2005 May; cited 13 Sep 2006]. <http://www.cochrane.org/resources/handbook/>.
  • Armstrong R, Jackson N, Doyle J, Waters E, and Howes F. It's in your hands: the value of handsearching in conducting systematic reviews of public health interventions. J Public Health (Oxf). 2005.  Dec; 27(4):388–91. [PubMed]
  • Centers for Disease Control and Prevention (CDC). Update: adverse events following civilian smallpox vaccination—United States, 2003. MMWR Morb Mortal Wkly Rep. 2003.  Apr 25; 52(16):360– 362–3. [PubMed]
  • Tannous H, Nasrallah F, and Marjani M. Spontaneous iliac vein rupture: case report and comprehensive review of the literature. Ann Vasc Surg. 2006.  Mar; 20(2):258–62. [PubMed]
  • Francis D, Batchelor P, and Gates P. Posttraumatic spinal cord herniation. J Clin Neurosci. 2006.  Jun; 13(5):582–6. [PubMed]

Articles from Journal of the Medical Library Association : JMLA are provided here courtesy of Medical Library Association

Formats:

Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...

Links

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...