Importance of case reports in anaesthesia

Definition

A case (from the Latin casus) is defined as something that occurs (occurrence), an event or happening.¹ According to the dictionary of the Royal Spanish Academy, to report is the action of conveying, communicating or giving notice.² Although the case could be assimilated to the individual or patient, the term refers in fact to the disease or the clinical condition at hand.¹ Case reports present clinical observations in a form that is particular to healthcare-related sciences.³ More specifically, they are a formal summary of a patient and his/her disease, including the presence or absence of signs and symptoms, diagnostic tests, treatment and outcomes.⁴

From the methodological point of view, reports and case series may be considered observational and descriptive studies.⁵ Traditionally, case reports and case series have been mixed indiscriminately in the literature. Articles categorized as case series have been published with only one patient reported, and case reports have been published with more than five patients described.⁶ Based on statistical, epidemiological and clinical criteria, five has been recently defined as the maximum number of patients that must be described in a case report; consequently, six or more patients described are considered a case series.⁷

History

In the history of medicine, case reports and case series have been an integral part of the biomedical literature. Case reports date back to 1600 B.C., in ancient Egypt.⁸ Similar narrative formats were found in Hippocratic manuscripts written circa 400 B.C.⁹ Sir William Osler (1849–1919), considered the father of modern medicine, believed that physicians had to keep detailed records of unusual situations in their clinical practice and make them public in a short and concise form.⁸

In our specialty, the first case of general anaesthesia with ether in 1846 was documented in a case report published by Bigelow.¹⁰ Up to this date, this case report may be considered as one of the most important in the history of medicine.¹¹Table 1 summarizes some salient case reports in the history of anaesthesiology.

Table 1.

Classic case reports and case series in anaesthesiology.

Year and author	Reason for the report	Reference
1846 Bigelow	First general anaesthesia with ether (Dr William Morton, October 16, 1846)	^10
1847 Simpson	General anaesthesia with chloroform	^12
1848 Anonymous	Death attributable to general anaesthesia with chloroform in Hannah Greener, a 15-year-old patient taken to a minor procedure	^13
1899 Bier	Effect of the intrathecal cocaine injection, including the description of post dural puncture headache	^14
1921 Pagés	Epidural anaesthesia	^15
1946 Mendelson	Pulmonary aspiration syndrome in obstetric patients	^16
1950 Winterbottom	Intraoperative awakening	^17
1960–62 Denborough	Malignant hyperthermia	^18,19
1963 Brody	Halothane-related hepatitis	^20
1975 Harrison	Successful treatment of malignant hyperthermia with dantrolene	^21

Source: Authors.

Since the 1940s, with the emergence of experimental designs followed by the idea and development of evidence-based medicine, great emphasis has been placed on quantitative studies with large sample sizes. Experimental trials are at the top of the hierarchy of clinical evidence, while case reports are lower down in the same classification.²² On the other hand, journals that publish studies with higher levels of evidence gain more prestige, and these studies are cited a larger number of times, giving a favourable shift to the impact factor. Case reports are usually cited less compared to prospective observational studies and clinical trials.²³ For a journal, this means that publishing case reports might have a potentially deleterious effect on the impact factor.²⁴ In the 1970s and 1980s, this gave rise to the so-called marginalization of case reports.¹

However, towards the end of the past century, case reports gained new popularity in the biomedical literature.¹ This phenomenon has been attributed mainly to three things, among others. First, in the hierarchy of evidence-based medicine, the single-case research methodology (trials with an N of 1) gained traction.²⁵ Second, in 1995, the Lancet introduced a section on peer reviewed case reports limited to 600 words, addressed mainly to physicians in training, under the premise that this group of practitioners have a more intense clinical exposure in terms of the number of patients compared to their faculty, and this may represent an important source of case reports.²⁶ And third, in 1998, the BMJ (originally the British Medical Journal) introduced a new type of article, i.e., evidence-based case report, in order to improve reader skills in terms of the application of the clinical evidence.²⁷

Current situation of case reports

Rarity by itself is no justification to report a case. Reported cases must contribute to knowledge creation and must give rise to hypotheses and research questions to be solved in subsequent clinical research; they must contribute to the information on known diseases, and to their diagnosis or treatment; and they must always accomplish a clear learning objective for the readers.^28–30

Up to this date, the number of case reports published continues to grow, and close to 1000 case reports (2%) of the 50 thousand indexed in MEDLINE every year relate to anaesthesiology (Fig. 1). In the Colombian Journal of Anaesthesia (Revista Colombiana de Anestesiología), close to 25% of all articles published are case reports.³¹

Fig. 1.

Case reports indexed in MEDLINE.

Source: Taken from www.pubmed.com (case reports [Publication Type]).

Considering that biomedical journals find themselves at a cross-roads at the present time because they need to respond to the irrefutable importance and the need for case reports on the one hand,³² and strive to increase their own impact factor on the other, editorial committees have defined more stringent criteria in terms of quality, novelty, exceptional interest, brevity and relevance of a case report for publication.³³ Indeed, the recent CARE declaration (from CAse REport) stated the guidelines that must be followed by all manuscripts of this type.³

Along these same lines, clearly recognizing the importance of case reports in anaesthesia, very prestigious journals have made the decision of transferring case reports^24,34 from their core publications to new journals exclusively devoted to case reports.³⁵

Consistent with all of the above, the Colombian Journal of Anaesthesia recently adhered to the CARE declaration guidelines in order to move towards the standardized format in which case reports are published.³⁶ Moreover, as proof of the journal's commitment regarding the importance of case reports as a valid strategy for scientific dissemination, this issue includes six case reports^37–41 and one case series.⁴² They were all subjected to a peer review process, they adhere most certainly to modern writing standards, and they will contribute to the education objectives that readers expect from these types of primary studies.

Funding

None.

Conflict of interest

None known.