**4. Initial management**

AP can be classified into two groups as mild AP, in which patients have no accompanying organ failure, and recover and can be orally fed within 48 hours; and severe AP, which is accompanied by organ failure and a lack of response to treatment. Most patients with severe AP have not suffered organ failure at the time of admission to emergency room, and so may be evaluated as mild AP,but deteriorate rapidly due to inadequate hydration and inadequate treatment. As such, the severity of the disease should be determined along at the time of diagnosis in the emergency room, and treatment should be planned accordingly [47, 48, 52, 65].

According to the Atlanta classification, severe AP is characterized by resistant/ persistent organ failure with no improvement within 48 hours, although in the absence of organ failure, the presence of local complications alone is an indicator of severe AP [66]. Patients who develop transient organ failure alongside local complications are classified as moderately severe AP (**Table 1**). The Atlanta classification evaluates the presence of organ failure based on Marshall's organ failure criteria. Accordingly, the presence of shock (systolic BP <90 mmHg), pulmonary failure (PaO2 < 60 mmHg), renal failure (creatinine >2 despite adequate hydration), and/ or the presence of gastrointestinal bleeding (>500 ml blood loss within 24 hours) should be evaluated as organ failure [48, 52, 67].

Besides the Atlanta classification, several scoring systems have been proposed for the determination of the severity in AP. These include Ranson's criteria,Acute Physiology and Chronic Health Examination-II, modified Glasgow score, Bedside Index for Severity in Acute Pancreatitis and the Balthazar CT Severity Index,none of which has been shown to be superior to any other, and they have only limited use in the emergency room, as they rely on too many parameters, and some give results only after 48 hours [68, 69]. The assessment of the patient in the emergency department is of utmost importance, with patient-related risk factors such as age, weight, comorbidities and vital signs as well as laboratory findings all being evaluated together (**Table 2**) [47, 52, 56, 65].


### **Table 1.**

*Atlanta classification 2015.*


### **Table 2.**

*Initial assessment for risk of severe AP.*

### **5. Treatment**

### **5.1 Fluid replacement**

The initial approach to AP involves aggressive fluid therapy, pain management and nutritional support. In AP, there is a large amount of fluid deficit due to losses from vomiting, reduced oral intake, passage of fluid into the third space, respiration and sweating. If the patient has no additional cardiovascular or renal disease, fluid replacement should be initiated at 5–10 ml/kg/hour. For patients presenting with evidence of hypovolemia and shock, 3 ml/kg of fluid should be given for 8–12 hours following a fluid bolus of 20 ml/kg in 30 minutes, with isotonic normal saline preferred as the fluid [47, 48, 52, 70–72]. A prospective study found hydration with Ringer's lactate solution to be more beneficial, although Ringer's lactate solution has been shown to activate trypsin in acinar cells, thereby making the patient more susceptible to injury due to its low pH. With normal saline, there is a risk of developing non-anion gap metabolic acidosis, and patients should be monitored accordingly during fluid replacement [2, 72]. An assessment should be made after 6, 24 and 48 hours to as certain whether the fluid administered is sufficient. With adequate hydration, the heart rate should drop below 120/min, mean arterial pressure (MAP) should be maintained between 65 and 85, and hematocrit (HCT) should be 35–44%. If the BUN value is initially high, a decrease upon hydration is an indicator of adequate hydration. Changes in blood urea nitrogen (BUN) values within the first 24 hours are particularly important [27, 47, 48, 73, 74]. If the BUN values continue to be high, or increase even further, acute tubular necrosis or resistant volume deficit should be suspected [27, 47, 52, 65, 75]. Another parameter that should be monitored during hydration is hematocrit. Continued hemoconcentration for more than 24 hours suggests the development of necrotizing pancreatitis, and so the patient's urine output, BUN and HCT values should be closely monitored. The development of severe pancreatitis should be considered in patients who do not respond to aggressive hydration for 6–12 hours [47, 48, 52].

### **5.2 Pain management**

Adequate hydration and the resolution of hypovolemia relieve ischemic pain secondary to hemoconcentration. Nevertheless, opioid analgesics are recommended for rapid pain management. Fentanyl can be used safely, especially in patients with kidney failure, in which intravenous (IV) fentanyl of 20–50 microgram is administered slowly over 10 minutes. Meperidine can be used as an alternative to morphine due to the spasm effect of morphine on the Sphincter of Oddi [2, 27, 76, 77].


### **Table 3.**

*Assessment for intensive care.*

## **5.3 Monitoring**

AP patients should be followed closely for 24 hours, with continued monitoring of blood pressure, temperature, pulse, oxygen saturation and urine output. Blood tests should be monitored for hematocrit, BUN and electrolytes (calcium, magnesium), and blood glucose should be maintained between 180 and 200 mg/ dl [2, 27, 52]. Intensive care follow-up is required for patients whose vital signs and laboratory values are unstable and / or continue (**Table 3**) [52].
