Intra-abdominal pressure: Time ripe to revise management guidelines of acute pancreatitis?

Table 1 Epidemiology of intra-abdominal hypertension and abdominal compartment syndrome in acute pancreatitis as previously reported in literature n (%)

Ref.	IAP monitoring	Definition of IAH	Incidence of IAH (among patients with SAP)	Definition of ACS	Incidence of ACS (among patients with SAP)
Pupelis et al[3]	Selected	NA	NA	IAP > 25 mmHg	18 (25)
De Waele et al[12]	Selected	IAP > 15 mmHg	21 (78)	NA	NA
Pupelis et al[13]	Selected	NA	NA	NA	NA
Keskinen et al[14]	Selected	IAP > 12 mmHg	31 (84)	IAP > 20 mmHg with new organ dysfunction	18 (49)
Zhang et al[15]	Unselected	IAP > 10 cm H2O (NA)	68 (76)	NA	NA
Rosas et al[16]	Unselected (45 patients)	NA	NA	NA	NA
Chen et al[17]	Unselected	IAP > 12 mmHg	44 (59)	IAP > 20 mmHg with new organ dysfunction	20 (27)
Al-Bahrani et al[18]	Unselected	IAP > 15 mmHg	11 (61)	IAH with organ dysfunction	10 (56)
Dambrauskas et al[19]	Unselected	IAP > 12 mmHg	19 (43)	IAP > 20 mmHg with new organ dysfunction	6 (14)
Mentula et al[20]	Unselected (26 patients with ACS)	NA	NA	IAP > 20 mmHg with new organ dysfunction	NA
Ke et al[21]	Unselected	IAP > 12 mmHg	36 (62)	IAP > 20 mmHg with new organ dysfunction	7 (12)
Bezmarevic et al[22]	Unselected	IAP > 12 mmHg	36 (71) (among patients with AP)	IAP > 20 mmHg with new organ dysfunction	6 (12) (among patients with AP)
			27 (97) (among patients with SAP)		6 (21) (among patients with SAP)
Boone et al[23]	Selected (12 patients undergoing decompressive laparotomy for ACS)	NA	NA	IAP > 20 mmHg with new organ dysfunction	NA
Davis et al[24]	Selected	NA	NA	IAP > 20 mmHg with new organ dysfunction	16 (35)
Bhandari et al[25]	Unselected	IAP > 12 mmHg	8 (20) (among patients with AP)	IAP > 20 mmHg with new organ dysfunction	3 (7.5) (among patients with AP)
			8 (50) (among patients with SAP)		3 (19) (among patients with SAP)
Aitken et al[26]	Unselected	IAP > 12 mmHg	36 (17) (among patients with AP)	NA	NA

IAP: Intra-abdominal pressure; IAH: Intra-abdominal hypertension; ACS: Abdominal compartment syndrome; NA: Not available; AP: Acute pancreatitis; SAP: Severe acute pancreatitis.

Table 2 Comparison of Atlanta, revised Atlanta and determinant based classification system of acute pancreatitis

	Atlanta[7]	Revised atlanta[27]	Determinant based system[28]
Mild	Minimal organ dysfunction and an uneventful recovery; lacks the features of severe acute pancreatitis. Usually normal enhancement of pancreatic parenchyma on contrast-enhanced computed tomography	No organ failure	No (peri)pancreatic necrosis and no organ failure2
		No local or systemic complications
Moderate		Organ failure2 that resolves within 48 h (transient organ failure) and/or local or systemic complications without persistent organ failure	Sterile (peri)pancreatic necrosis and/or transient organ failure (< 48 h)2
Severe	Associated with organ failure1 and/or local complications such as acute fluid collections, necrosis, abscess or pseudocyst	Persistent organ failure2 (> 48 h)	Infected (peri)pancreatic necrosis or persistent organ failure (> 48 h)2
		Single organ failure
		Multiple organ failure
Critical			Infected (peri)pancreatic necrosis and persistent organ failure (> 48 h)2

¹Organ failure and systemic complications defined as - Shock (Systolic blood pressure < 90 mmHg), Pulmonary insufficiency (PaO₂≤ 60 mmHg), Renal failure (Creatinine ≥ 177 μmol/L or ≤ 2 mg/dL after rehydration), Gastrointestinal bleeding (500 mL in 24 h), Disseminated intravascular coagulation (Platelets ≤ 100000/mm, fibrinogen < 1.0 g/L and fibrin-split products > 80 μg/L), and Severe metabolic disturbances (Calcium ≤ 1.87 mmol/L or ≤ 7.5 mg/dL);

²Organ failure defined by modified Marshall scoring (Table 3)[29].

Table 3 Modified Marshall scoring system for organ dysfunction[29]

Organ System	Score
	0	1	2	3	4
Respiratory (PaO2/FiO2)	> 400	301-400	201-300	101-200	≤ 101
Renal1
(serum creatinine, mmol/L)	≤ 134	134-169	170-310	311-439	> 439
(serum creatinine, mg/dL)	< 1.4	1.4-1.8	1.9-3.6	3.6-4.9	> 4.9
Cardiovascular (systolic blood pressure, mmHg)2	> 90	< 90 and fluid responsive	< 90 and not fluid responsive	< 90, pH < 7.3	< 90, pH < 7.2

¹A score for patients with pre-existing chronic renal failure depends on the extent of further deterioration of baseline renal function. No formal correction exists for a baseline serum creatinine ≥ 134 μmol/L or ≥ 1.4 mg/dL;

²Off inotropic support. For non-ventilated patients, the FiO₂ can be estimated from below: (1) Supplemental oxygen (L/min) is room air, the percentage of FiO₂ is 21%; (2) Supplemental oxygen is 2 L/min, 4 L/min, FiO₂ is 25%, 30%, respectively; (3) Supplemental oxygen is 6-8 L/min, FiO₂ is 40%; and (4) Supplemental oxygen is 9-10 L/min, FiO₂ is 50%. A score of 2 or more in any system defines the presence of organ failure.

Table 4 Ways in which intra-abdominal hypertension/abdominal compartment syndrome can be predisposed in patients with acute pancreatitis

Diminished abdominal wall compliance

Prone positioning, head of bed > 30°

High body mass index, central obesity

Acute respiratory failure, especially with elevated intrathoracic pressure

Edema due to excess fluid administered during resuscitation

Increased intra-luminal contents

Gastroparesis

Ileus

Colonic pseudo-obstruction

Increased abdominal contents

Ascites (due to causes such as acute fluid collections, liver dysfunction)

Capillary leak / fluid resuscitation (overload)

Acidosis (pH < 7.2)

Hypotension

Hypothermia (core temperature < 33 °C)

Coagulopathy (platelets < 55000/mm3 or prothrombin time > 15 s or partial thromboplastin time > 2 times normal or international standardised ratio > 1.5)

Massive fluid resuscitation (> 5 L/d)

Oliguria

Sepsis