Development and validation of a diagnostic prediction model distinguishing complicated from uncomplicated diverticulitis

Emergency medicine updates: Acute diverticulitis

INTRODUCTION

Acute diverticulitis is a condition commonly seen in the emergency department (ED). Therefore, it is important for emergency medicine clinicians to be aware of the current evidence regarding the diagnosis and management of this disease.

OBJECTIVE

This paper evaluates key evidence-based updates concerning acute diverticulitis for the emergency clinician.

DISCUSSION

Diverticulitis is a complication of diverticulosis and most commonly affects the sigmoid and descending colon in Western countries. History and examination can suggest the diagnosis, with abdominal pain and tenderness in the left lower quadrant being the most common symptom and sign, respectively. Change in bowel habits and fever may also occur. Laboratory testing may demonstrate leukocytosis or an elevated C-reactive protein. Imaging options can include computed tomography (CT) of the abdomen and pelvis with intravenous contrast, magnetic resonance imaging (MRI), or ultrasound (US), though most classification systems for diverticulitis incorporate CT findings. While the majority of diverticulitis cases are uncomplicated, complications may affect up to 25% of patients. Treatment of complicated diverticulitis requires antibiotics and surgical consultation. Antibiotics are not required in select patients with uncomplicated diverticulitis. Appropriate patients for supportive care without antibiotics should be well-appearing, have pain adequately controlled, be able to tolerate oral intake, be able to follow up, have no complications, and have no immunocompromise or severe comorbidities.

CONCLUSIONS

An understanding of literature updates can improve the ED care of patients with acute diverticulitis.

The WSES/SICG/ACOI/SICUT/AcEMC/SIFIPAC guidelines for diagnosis and treatment of acute left colonic diverticulitis in the elderly

Acute left colonic diverticulitis (ALCD) in the elderly presents with unique epidemiological features when compared with younger patients. The clinical presentation is more nuanced in the elderly population, having higher in-hospital and postoperative mortality. Furthermore, geriatric comorbidities are a risk factor for complicated diverticulitis. Finally, elderly patients have a lower risk of recurrent episodes and, in case of recurrence, a lower probability of requiring urgent surgery than younger patients. The aim of the present work is to study age-related factors that may support a unique approach to the diagnosis and treatment of this problem in the elderly when compared with the WSES guidelines for the management of acute left-sided colonic diverticulitis. During the 1° Pisa Workshop of Acute Care & Trauma Surgery held in Pisa (Italy) in September 2019, with the collaboration of the World Society of Emergency Surgery (WSES), the Italian Society of Geriatric Surgery (SICG), the Italian Hospital Surgeons Association (ACOI), the Italian Emergency Surgery and Trauma Association (SICUT), the Academy of Emergency Medicine and Care (AcEMC) and the Italian Society of Surgical Pathophysiology (SIFIPAC), three panel members presented a number of statements developed for each of the four themes regarding the diagnosis and management of ALCD in older patients, formulated according to the GRADE approach, at a Consensus Conference where a panel of experts participated. The statements were subsequently debated, revised, and finally approved by the Consensus Conference attendees. The current paper is a summary report of the definitive guidelines statements on each of the following topics: diagnosis, management, surgical technique and antibiotic therapy.

Machine Learning Model for Outcome Prediction of Patients Suffering from Acute Diverticulitis Arriving at the Emergency Department-A Proof of Concept Study

Background & Aims: We aimed at identifying specific emergency department (ED) risk factors for developing complicated acute diverticulitis (AD) and evaluate a machine learning model (ML) for predicting complicated AD. Methods: We analyzed data retrieved from unselected consecutive large bowel AD patients from five hospitals from the Mount Sinai health system, NY. The study time frame was from January 2011 through March 2021. Data were used to train and evaluate a gradient-boosting machine learning model to identify patients with complicated diverticulitis, defined as a need for invasive intervention or in-hospital mortality. The model was trained and evaluated on data from four hospitals and externally validated on held-out data from the fifth hospital. Results: The final cohort included 4997 AD visits. Of them, 129 (2.9%) visits had complicated diverticulitis. Patients with complicated diverticulitis were more likely to be men, black, and arrive by ambulance. Regarding laboratory values, patients with complicated diverticulitis had higher levels of absolute neutrophils (AUC 0.73), higher white blood cells (AUC 0.70), platelet count (AUC 0.68) and lactate (AUC 0.61), and lower levels of albumin (AUC 0.69), chloride (AUC 0.64), and sodium (AUC 0.61). In the external validation cohort, the ML model showed AUC 0.85 (95% CI 0.78–0.91) for predicting complicated diverticulitis. For Youden’s index, the model showed a sensitivity of 88% with a false positive rate of 1:3.6. Conclusions: A ML model trained on clinical measures provides a proof of concept performance in predicting complications in patients presenting to the ED with AD. Clinically, it implies that a ML model may classify low-risk patients to be discharged from the ED for further treatment under an ambulatory setting.

Excessive Body Weight and Diverticular Disease

BACKGROUND

The worldwide proportion of overweight adults almost doubled from 22% in 1975 to 39% in 2016. Comparably, for the USA and Germany in 2016, the proportion was 68 and 56.8%, respectively. In Olmsted County, Minnesota, the prevalence of diverticulitis also doubled between 1980 and 2007, from 19 to 40%. Obesity substantially increases the risk of multiple gastrointestinal (GI) diseases and non-GI diseases. In a narrative review, we examined the evidence on whether obesity also increases the risk for the development of diverticulosis or diverticular disease and its outcome.

SUMMARY

Evidence suggests that being overweight (body mass index ≥25 kg/m2) or obese (≥30 kg/m2), especially viscerally obese, is a risk factor for diverticulosis, diverticular disease and diverticulitis, diverticular bleeding, more severe or complicated disease, recurrent disease, and for worse outcomes after surgery.

KEY MESSAGES

There is a well-founded association between overweight and diverticular disease as well as diverticulosis. It is not clear whether overweight per se or confounders linked with it are responsible for the association. However, means to fight the overweight and obesity epidemic might also help to reduce the prevalence of morbidity and mortality from diverticular disease.

The Association of Coloproctology of Great Britain and Ireland consensus guidelines in emergency colorectal surgery

AIM

There is a requirement for an expansive and up to date review of the management of emergency colorectal conditions seen in adults. The primary objective is to provide detailed evidence-based guidelines for the target audience of general and colorectal surgeons who are responsible for an adult population and who practise in Great Britain and Ireland.

METHODS

Surgeons who are elected members of the Association of Coloproctology of Great Britain and Ireland Emergency Surgery Subcommittee were invited to contribute various sections to the guidelines. They were directed to produce a pathology-based document using literature searches that were systematic, comprehensible, transparent and reproducible. Levels of evidence were graded. Each author was asked to provide a set of recommendations which were evidence-based and unambiguous. These recommendations were submitted to the whole guideline group and scored. They were then refined and submitted to a second vote. Only those that achieved >80% consensus at level 5 (strongly agree) or level 4 (agree) after two votes were included in the guidelines.

RESULTS

All aspects of care (excluding abdominal trauma) for emergency colorectal conditions have been included along with 122 recommendations for management.

CONCLUSION

These guidelines provide an up to date and evidence-based summary of the current surgical knowledge in the management of emergency colorectal conditions and should serve as practical text for clinicians managing colorectal conditions in the emergency setting.

Interval colonoscopy following acute diverticulitis should not be discouraged yet: results from a retrospective cohort

BACKGROUND

Although included in some guidelines, the recommendation of interval colonoscopy after an acute diverticulitis (AD) episode has recently been questioned. In this study, we evaluated the incidence of colon cancer during the follow-up of an episode of AD.

METHODS

A retrospective review was carried out of patients with conservatively treated AD at our Institution (January 2011 to December 2018) with or without endoscopic study. Patients who had no colonoscopy performed were followed for two years. The demographic, clinical, radiological, follow-up and anatomopathological records were analysed. We determined CT scan validity for the differential diagnosis of CC and AD; sensibility, specificity, predictive values and likelihood ratios were calculated. Patients lost to follow-up and patients who had had colonoscopy in the previous three years were excluded.

RESULTS

This study included 285 patients with a mean age of 59 years. A total of 225 interval colonoscopies were performed and 60 patients without colonoscopy were followed up. There were 19 CC (6.7%) diagnosed, 14 with interval colonoscopy and 5 during follow-up; 8 (42.1%) happened in patients who had had an episode of uncomplicated AD. Although CT scan accuracy is high, 87.7%, positive and negative likelihood ratios were low, 4.67 and 0.64, respectively.

CONCLUSIONS

Interval colonoscopy should still be advisable after an episode of AD. The rationale for this statement is based on a non-negligible rate of hidden CC and an important uncertainty in the differential diagnosis.