Fluid therapy in acute pancreatitis - aggressive or adequate? Time for reappraisal

Meta-analysis and trial sequential analysis of randomized controlled trials comparing aggressive versus non-aggressive intravenous fluid therapy in acute pancreatitis: an insight into the existence of type 2 error

BACKGROUND AND AIM

We aimed to evaluate comparative outcomes of aggressive versus non-aggressive intravenous fluid (IVF) therapy in patients with acute pancreatitis.

METHODS

A systematic search of electronic data sources and bibliographic reference lists were conducted. All randomized controlled trials (RCTs) reporting outcomes of aggressive versus non-aggressive IVF therapy in acute pancreatitis were included and their risk of bias were assessed. Effect sizes were determined for overall mortality, systemic inflammatory response syndrome (SIRS), sepsis, respiratory failure, pancreatic necrosis, severe pancreatitis, clinical improvement, AKI, and length of stay using random-effects modeling. Trial sequential analysis was conducted to determine risk of types 1 or 2 errors.

RESULTS

We included 10 RCTs reporting 993 patients with acute pancreatitis who received aggressive (n = 475) or non-aggressive (n = 518) IVF therapy. Aggressive IVF therapy was associated with significantly higher rate of sepsis (OR: 2.68, P = 0.0005) and longer length of stay (MD: 0.94, P < 0.00001) compared with the non-aggressive approach. There was no statistically significant difference in mortality (RD: 0.02, P = 0.31), SIRS (OR: 0.93, P = 0.89), respiratory failure (OR: 2.81, P = 0.07), pancreatic necrosis (OR: 1.98, P = 0.06), severe pancreatitis (OR: 1.31, P = 0.38), clinical improvement (OR: 1.12, P = 0.83) or AKI (OR: 1.06, P = 0.91) between the two groups. Sub-group analysis demonstrated higher morbidity and mortality associated with the aggressive approach in more severe disease. Trial sequential analysis detected risk of type 2 error.

CONCLUSIONS

Aggressive IVF therapy may be associated with higher morbidity in patients with acute pancreatitis compared with the non-aggressive approach, particularly in patients with more severe disease. It may also prolong length of hospital stay. The available evidence is subject to type 2 error indicating the need for adequately powered RCTs.

Lactated Ringers Use in the First 24 Hours of Hospitalization Is Associated With Improved Outcomes in 999 Patients With Acute Pancreatitis

INTRODUCTION

Recent pilot trials in acute pancreatitis (AP) found that lactated ringers (LR) usage may result in decreased risk of moderately severe/severe AP compared with normal saline, but their small sample sizes limit statistical power. We investigated whether LR usage is associated with improved outcomes in AP in an international multicenter prospective study.

METHODS

Patients directly admitted with the diagnosis of AP were prospectively enrolled at 22 international sites between 2015 and 2018. Demographics, fluid administration, and AP severity data were collected in a standardized prospective manner to examine the association between LR and AP severity outcomes. Mixed-effects logistic regression analysis was performed to determine the direction and magnitude of the relationship between the type of fluid administered during the first 24 hours and the development of moderately severe/severe AP.

RESULTS

Data from 999 patients were analyzed (mean age 51 years, female 52%, moderately severe/severe AP 24%). Usage of LR during the first 24 hours was associated with reduced odds of moderately severe/severe AP (adjusted odds ratio 0.52; P = 0.014) compared with normal saline after adjusting for region of enrollment, etiology, body mass index, and fluid volume and accounting for the variation across centers. Similar results were observed in sensitivity analyses eliminating the effects of admission organ failure, etiology, and excessive total fluid volume.

DISCUSSION

LR administration in the first 24 hours of hospitalization was associated with improved AP severity. A large-scale randomized clinical trial is needed to confirm these findings.

Intravenous fluid therapy in patients with severe acute pancreatitis admitted to the intensive care unit: a narrative review

Patients with acute pancreatitis (AP) often require ICU admission, especially when signs of multiorgan failure are present, a condition that defines AP as severe. This disease is characterized by a massive pancreatic release of pro-inflammatory cytokines that causes a systemic inflammatory response syndrome and a profound intravascular fluid loss. This leads to a mixed hypovolemic and distributive shock and ultimately to multiorgan failure. Aggressive fluid resuscitation is traditionally considered the mainstay treatment of AP. In fact, all available guidelines underline the importance of fluid therapy, particularly in the first 24–48 h after disease onset. However, there is currently no consensus neither about the type, nor about the optimal fluid rate, total volume, or goal of fluid administration. In general, a starting fluid rate of 5–10 ml/kg/h of Ringer’s lactate solution for the first 24 h has been recommended. Fluid administration should be aggressive in the first hours, and continued only for the appropriate time frame, being usually discontinued, or significantly reduced after the first 24–48 h after admission. Close clinical and hemodynamic monitoring along with the definition of clear resuscitation goals are fundamental. Generally accepted targets are urinary output, reversal of tachycardia and hypotension, and improvement of laboratory markers. However, the usefulness of different endpoints to guide fluid therapy is highly debated. The importance of close monitoring of fluid infusion and balance is acknowledged by most available guidelines to avoid the deleterious effect of fluid overload. Fluid therapy should be carefully tailored in patients with severe AP, as for other conditions frequently managed in the ICU requiring large fluid amounts, such as septic shock and burn injury. A combination of both noninvasive clinical and invasive hemodynamic parameters, and laboratory markers should guide clinicians in the early phase of severe AP to meet organ perfusion requirements with the proper administration of fluids while avoiding fluid overload. In this narrative review the most recent evidence about fluid therapy in severe AP is discussed and an operative algorithm for fluid administration based on an individualized approach is proposed.

Lactate Ringer's Versus Normal Saline in the Management of Acute Pancreatitis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Fluid therapy plays a critical role in the management of acute pancreatitis. Normal saline (NS) is commonly used in these patients. However, Lactate Ringer's (LR) has also been shown to be useful for this condition.

AIM

To assess the effect of LR compared to NS in patients with acute pancreatitis.

METHODS

We searched in three electronic databases from inception to December 2020 for randomized controlled trials (RCTs). Outcomes were mortality, intensive care unit (ICU) admission, hospital stay, and Systemic Inflammatory Response Syndrome (SIRS) at 24, 48, and 72 h. The risk of bias was assessed using the Risk of Bias 2.0 tool. All meta-analyses were performed using a random-effects model.

RESULTS

Four RCTs comprising 248 patients were included. The mean age ranged from 42.3 to 63.8 years and 49% of patients were men. Patients treated with LR had similar risk of mortality (risk ratio [RR], 0.53; 95% confidence interval [CI], 0.09-3.00) and SIRS at 24 h (RR, 0.69; 95% CI, 0.32-1.51), 48 h (RR, 0.80; 95% CI, 0.46-1.41), and 72 h (RR, 0.68; 95% CI, 0.37-1.25) compared to NS. LR had significantly lower hospital stay (mean difference, - 1.10; 95% CI, - 1.92 to - 0.28) and lower risk of ICU admission (RR, 0.42; 95% CI, 0.20-0.89) compared to NS. The risk of bias was low in nearly all RCTs.

CONCLUSION

No differences were found in the mortality and SIRS at 24, 48, and 72 h in patients treated with LR and NS. In contrast, patients who received LR had a lower risk of ICU admission and lower hospital stay than NS.

Lactated Ringers Does Not Reduce SIRS in Acute Pancreatitis Compared to Normal Saline: An Updated Meta-Analysis

BACKGROUND

We aimed to compare outcomes according to a Lactated Ringers (LR) versus Normal Saline (NS)-based strategy for acute pancreatitis.

METHODS

A database search through November 2020 was done to identify studies comparing LR to NS for fluid rehydration in AP. The primary endpoint was systemic inflammatory response syndrome (SIRS) at 24 h. Mantel-Haenszel pooled odds ratios (OR) and 95% confidence intervals were constructed using a random effects model. Heterogeneity was assessed using the I² statistic. Publication bias was assessed using funnel plots.

RESULTS

Six studies were included totaling 549 patients. No difference in the odds of developing SIRS was noted at 24 h (pooled OR 0.59, 95% CI 0.22-1.62, P = 0.31) between LR and NS. I² indices showed low heterogeneity between the groups, and a funnel plot showed no obvious publication bias. There was no difference between LR and NS found for SIRS at 48 and 72 h, mortality, and other secondary outcomes. LR was associated with a decreased need for ICU admission.

CONCLUSIONS

This updated meta-analysis does not support the previously published finding that the use of LR (rather than NS) leads to a statistically significant decreased odds of SIRS in acute pancreatitis.

Early Weight-Based Aggressive vs. Non-Aggressive Goal-Directed Fluid Resuscitation in the Early Phase of Acute Pancreatitis: An Open-Label Multicenter Randomized Controlled Trial (The WATERFALL Trial), Design, and Rationale

Treatment options are limited for acute pancreatitis (AP). Early aggressive fluid resuscitation (AFR) has been widely considered beneficial because of theoretical improvement in end-organ perfusion, including the pancreas and gut, with pancreatic necrosis and bacterial translocation as consequences of ischemia. There is scarce direct evidence for its association to improved outcomes. Furthermore, it has been described that AFR may be associated with poor outcomes in severe AP. WATERFALL is an investigator-initiated international multicenter open-label randomized controlled trial comparing AFR vs. moderate fluid resuscitation (MFR) in AP. The main outcome variable will be the incidence of moderate to severe AP (a clinically relevant outcome that has been validated). Aggressive fluid resuscitation will consist in lactated Ringer solution (LR) 20-mL/kg bolus (administered over 2 h) followed by LR 3 mL/kg per hour. Patients randomized to MFR will receive an LR bolus 10 mL/kg in case of hypovolemia or no bolus in patients with normal volemia, followed by LR 1.5 mL/kg per hour. The patients will be assessed at 3 (±1), 12 (±4), 24 (±4), 48 (±4), and 72 (±4) h from recruitment, and fluid resuscitation will be adjusted to the patient's clinical and analytical status according to a protocol. Based on a prospective multicenter study, the incidence of moderate to severe AP is 35%. Sample sizes of 372 patients per group (overall 744) achieve 80% power to detect a difference in the incidence of moderate to severe AP of 10%, at a significance level (α) of 0.05 using a two-sided z-test, assuming a 10% dropout rate. These results assume that three sequential tests are made using the O'Brien-Fleming spending function to determine the test boundaries.

Organ Failure Due to Systemic Injury in Acute Pancreatitis

Acute pancreatitis may be associated with both local and systemic complications. Systemic injury manifests in the form of organ failure, which is seen in approximately 20% of all cases of acute pancreatitis and defines "severe acute pancreatitis." Organ failure typically develops early in the course of acute pancreatitis, but also may develop later due to infected pancreatic necrosis-induced sepsis. Organ failure is the most important determinant of outcome in acute pancreatitis. We review here the current understanding of the risk factors, pathophysiology, timing, impact on outcome, and therapy of organ failure in acute pancreatitis. As we discuss the pathophysiology of severe systemic injury, the distinctions between markers and mediators of severity are highlighted based on evidence supporting their causality in organ failure. Emphasis is placed on clinically relevant end points of organ failure and the mechanisms underlying the pathophysiological perturbations, which offer insight into potential therapeutic targets to treat.

The utility of neutrophil to lymphocyte ratio and fluid sequestration as an early predictor of severe acute pancreatitis

It is important to identify the patients with high-risk progression to develop severe acute pancreatitis (SAP). The study was to assess whether neutrophil to lymphocyte ratio (NLR) and fluid sequestration (FS) could represent useful markers for predicting the severity. A total of 1639 patients who underwent clinical diagnosis of AP was performed. Various serologic and clinical parameters on admission were investigated. Chronologic change in NLR and FS were analyzed, and theirs utility for predicting severity of AP was evaluated by receiver operator characteristic (ROC) curve analysis. Correlation analysis was assessed by Spearman's rank test. NLR and FS levels were both increased significantly in SAP and positively correlated with Ranson score and hospital stays. The ROC curve analyses showed the optimal cut-off values of NLR for admission with day0, day1, day2 were 9.64, 6.66 and 6.50, giving sensitivity of 77-82%. The optimal cut-off values of FS for admission with day1, day2, day3 were 1375 ml, 2345 ml and 3424 ml, giving sensitivity of 62-75%. Moreover, measurement of NLR and FS together exhibited a similar area under curve (AUC) and sensitivity for SAP prediction compared with the those of Ranson score. Increase of NLR and FS are correlated with severity and can be suggested as a predictive factor in an early stage of AP.

Clinical update on fluid therapy and nutritional support in acute pancreatitis

BACKGROUND/OBJECTIVES

The aim of this focused review is to provide a valuable and updated source of information for clinical practice on fluid therapy (FT) and nutritional support in acute pancreatitis (AP).

METHODS

The review encompasses important new clinical information that has become available for understanding and offering these specific treatments since the 2013 publication of two guidelines, both the joint International Association of Pancreatology and American Pancreatic Association and the American College of Gastroenterology. The 2015 Revised Japanese Guideline is discussed selectively. To this end, the review is divided into 7 sections, including timing and cause of mortality; severity classification systems; predicting severity; response to treatment; nutritional support; fluid therapy and steps for further research.

CONCLUSIONS

In mild AP, begin oral feeding when nausea, vomiting and abdominal pain are improving. In (predicted) severe AP, feeding decisions should commence by 72 h, offering oral feeding if GI symptoms improve or enteral feeding if patients are symptomatic and/or intolerant to orals. All patients should be offered goal-directed FT during the first 6-12 h of presentation. Cautious FT is advised in those age >55 years or with preexisting organ failure or predictors of developing fluid sequestration.

Influence of comorbidity on outcomes of older patients with acute pancreatitis based on a national administrative database

BACKGROUND

Little information is available on the influence of comorbidities on outcomes of older patients with acute pancreatitis. This study aimed to investigate the influence of comorbidities on outcomes of older patients with acute pancreatitis using data from a national Japanese administrative database.

METHODS

A total of 14 322 older patients (≥70 years) with acute pancreatitis were referred to 1090 hospitals between 2010 and 2012 in Japan. We collected patients' data from the administrative database to compare the in-hospital mortality and length of stay of older patients with acute pancreatitis. The patients were categorized into four groups according to comorbidity level using the Charlson Comorbidity Index (CCI): none (CCI score=0; n=6890); mild (1; n=3874); moderate (2; n=2192) and severe (≥3; n=1366).

RESULTS

Multiple logistic and linear regression analyses revealed that severe comorbidity was significantly associated with higher in-hospital mortality and longer length of stay [odds ratio (OR)=2.26; 95% confidence interval (CI): 1.75-2.92, P<0.001 and coefficient 4.37 days; 95% CI: 2.89-5.85, P<0.001, respectively]. In addition, cardiovascular and renal diseases were the most significant comorbidities affecting outcomes of the older patients. ORs of cardiovascular and renal diseases for mortality were 1.44 (95% CI: 1.13-1.85, P=0.003) and 2.69 (95% CI: 1.88-3.85, P<0.001), respectively, and coefficients for length of stay were 3.01 days (95% CI: 1.34-4.67, P<0.001) and 3.72 days (95% CI: 1.01-6.42, P=0.007), respectively.

CONCLUSION

This study demonstrated that comorbidities significantly influenced outcomes of older patients with acute pancreatitis and cardiovascular and renal comorbidities were significant factors affecting outcomes.