Early risk stratification of post-endoscopic retrograde cholangiopancreatography pancreatitis using 4-hour serum amylase and lipase: A prospective study

Table 1 Baseline characteristics and procedural findings of the study, mean ± SD/n (%)

Variable	Total patients (n = 1915)
Age, years	64.1 ± 17.5
Sex
Male	1068 (55.8)
Female	847 (44.2)
BMI, kg/m2	24.1 ± 4.0
Smoking	330 (17.2)
Alcohol intake	494 (25.8)
Amounts of alcohol (g)	3.1 ± 4.4
History of acute pancreatitis	49 (2.6)
Initial laboratory findings
WBC, μL	8536.1 ± 4542.9
Hb, g/dL	12.6 ± 2.0
Platelet, μL	225.0 ± 90.2
AST, IU/L	195.7 ± 334.5
ALT, IU/L	185.1 ± 223.2
GGT, g/dL	423.3 ± 441.7
Total bilirubin, mg/dL	3.5 ± 5.0
Amylase, IU/L	63.7 ± 41.3
Lipase, IU/L	61.1 ± 107.9
Acute cholangitis on admission	807 (42.1)
PTBD prior to ERCP	18 (0.9)
PTGBD prior to ERCP	50 (2.6)
Total procedure time, minute	15.5 ± 10.1
Selective deep cannulation time, minute	4.7 ± 5.8
Primary infundibulotomy	275 (14.4)
EPBD	314 (16.4)
Endoscopic sphincterotomy	1710 (89.3)
Biliary stent placement	1298 (67.8)
Pancreatic stent placement	380 (19.8)

BMI: Body mass index; WBC: White blood cell; Hb: Hemoglobin; AST: Aspartate transaminase; ALT: Alanine transaminase; GGT: Gamma glutamyl transpeptidase; PTBD: Percutaneous transhepatic biliary drainage; ERCP: Endoscopic retrograde cholangiopancreatography; PTGBD: Percutaneous transhepatic gallbladder drainage; EPBD: Endoscopic papillary balloon dilatation.

Table 2 Clinical outcomes and procedure-related adverse events, mean ± SD/n (%)

Variable	Total patients (n = 1915)
Laboratory findings at 4 hours after ERCP
AST, IU/L	154 ± 265.5
ALT, IU/L	184.1 ± 214.7
GGT, g/dL	408.2 ± 398.0
Total bilirubin, mg/dL	3.4 ± 4.7
Amylase, IU/L	131.1 ± 259.3
Lipase, IU/L	261.3 ± 894.7
Laboratory findings at 24 hours after ERCP
AST, IU/L	114.8 ± 232.2
ALT, IU/L	161.3 ± 188.4
GGT, g/dL	379.8 ± 356.2
Total bilirubin, mg/dL	2.9 ± 4.0
Amylase, IU/L	160.4 ± 296.9
Lipase, IU/L	258.7 ± 683.5
PEP	117 (6.1)
Severity of PEP
Mild	79 (67.5)
Moderately severe	31 (26.5)
Severe	7 (6.0)
Hyperamylasemia	218 (11.4)
Procedure-related adverse events
Perforation	4 (0.2)
Significant bleeding	51 (2.7)
Post-ERCP cholecystitis	21 (1.1)
Length of hospitalization, days	8.4 ± 31.6
All-cause mortality within 30 days	20 (1.9)

ERCP: Endoscopic retrograde cholangiopancreatography; AST: Aspartate transaminase; ALT: Alanine transaminase; GGT: Gamma glutamyl transpeptidase; PEP: Post-endoscopic retrograde cholangiopancreatography pancreatitis.

Table 3 Diagnostic performance of 4-hour and 24-hour amylase and lipase for post-endoscopic retrograde cholangiopancreatography pancreatitis prediction

Variables	Time point	AUC	Cut-off (IU/L)	Sensitivity	Specificity	PPV	NPV	AUC difference (4 hours-24 hours, 95%CI)	P value
Amylase	4-hour	0.877	119.5	0.846	0.806	0.221	0.988	-0.087 (-0.124 to -0.049)	< 0.001
	24-hour	0.963	301	0.957	0.942	0.519	0.997
Lipase	4-hour	0.893	488.5	0.863	0.862	0.287	0.990	-0.061 (-0.095 to -0.027)	< 0.001
	24-hour	0.954	443	0.897	0.927	0.443	0.993

The upper normal limit was defined as 100 IU/L for serum amylase and 60 IU/L for serum lipase. AUC: Area under the curve; PPV: Positive predictive value; NPV: Negative predictive value; CI: Confidence interval.

Table 4 Cut-off 4-hour post-endoscopic retrograde cholangiopancreatography amylase and lipase levels for predicting post-endoscopic retrograde cholangiopancreatography pancreatitis

Variables	Cut-off value	Sensitivity	Specificity	PPV	NPV
Amylase	1.2 × UNL	0.846	0.806	0.221	0.988
	2.0 × UNL	0.684	0.911	0.333	0.978
	3.0 × UNL	0.513	0.956	0.429	0.968
	4.0 × UNL	0.385	0.971	0.464	0.96
Lipase	2.0 × UNL	0.906	0.774	0.207	0.992
	3.0 × UNL	0.863	0.853	0.276	0.99
	4.0 × UNL	0.752	0.886	0.3	0.982
	8.0 × UNL	0.897	0.927	0.443	0.993

UNL: Upper normal limit; PPV: Positive predictive value; NPV: Negative predictive value.