New Atlanta Classification of acute pancreatitis in intensive care unit: Complications and prognosis

Highlights

• 21% of patients admitted to ICU for acute pancreatitis (AP) are moderately severe.

• All the patients with moderately severe AP admitted to ICU have complications.

• Most patients with moderately severe AP have non-infectious systemic complications.

• 66.7% of patients with moderately severe AP suffer an infectious complication.

• ICU mortality in patients with moderately severe acute pancreatitis is very low.

Abstract

Background

The updated Atlanta Classification of acute pancreatitis (AP) in adults defined three levels of severity according to the presence of local and/or systemic complications and presence and length of organ failure. No study focused on complications and mortality of patients with moderately severe AP admitted to intensive care unit (ICU). The main aim of this study is to describe the complications developed and outcomes of these patients and compare them to those with severe AP.

Methods

Prospective, observational study. We included patients with acute moderately severe or severe AP admitted in a medical–surgical ICU during 5 years. We collected demographic data, admission criteria, pancreatitis etiology, severity of illness, presence of organ failure, local and systemic complications, ICU length of stay, and mortality.

Results

Fifty-six patients were included: 12 with moderately severe AP and 44 with severe. All patients developed some kind of complications without differences on complications rate between moderately severe or severe AP. All the patients present non-infectious systemic complications, mainly acute respiratory failure and hemodynamic failure. 82.1% had an infectious complication, mainly non-pancreatic infection (66.7% on moderately severe AP vs. 79.5% on severe, p = 0.0443). None of the patients with moderately severe AP died during their intensive care unit stay vs. 29.5% with severe AP (p = 0.049).

Conclusions

Moderately severe AP has a high rate of complications with similar rates to patients with severe AP admitted to ICU. However, their ICU mortality remains very low, which supports the existence of this new group of pancreatitis according to their severity.

Introduction

The estimated incidence of acute pancreatitis (AP) is about 15–40 episodes/100.000 inhabitants/year, with an increasing trend according recent studies [1], [2], [3], [4], [5], [6]. Approximately 2.9% of patients with AP will require admission to the intensive care unit (ICU) due to development of severe complications [7].

The treatment of severe acute pancreatitis admitted to ICU has changed in recent years, evolving into a conservative manner [8], [9], [10], [11]. Some studies have demonstrated that this change on treatment guidelines is associated with lower mortality [6], [7], [12], [13]; however, other studies report that mortality of these patients remains unchanged [2], [14]. Mortality has been associated to more severe illness, early surgical treatment, infected necrosis, and increasing age [2], [14], [15], [16], [17], [18].

In 2012, the Atlanta Classification of acute pancreatitis in adults (> 18 years) [19] was updated to include modern concepts of the disease, addressing areas of confusion, improving the clinical assessment of severity, standardized data report, assisting the objective evaluation of new treatments, and facilitating the communication among treating physicians and between institutions [20]. It has defined three levels of severity according to the presence of local or systemic complications, and the presence and length of organ failure: mild, moderately severe, and severe.

Some studies focused on complications and mortality of patients with severe AP admitted to ICU [12], [14], [15], [21], [22], [23], [24], [25], showing that these patients have an elevated mortality and a high rate of systemic complications, especially infections and respiratory complications, requiring respiratory support in more than half of the patients [12], [18], [23].

None of these studies have classified severe AP according to the new Atlanta Classification [20]. Moreover, there are many uncertainties about complications and mortality of patients with moderate AP admitted in ICU [23].

The main aim of this study is to describe the complications of patients with moderately severe acute pancreatitis, developed during their stay in the ICU according to the new Atlanta Classification [20]. In second place, to described ICU mortality and compared with severe AP.