Page 12 - Acute Pancreatitis (Viêm tụy cấp)

CHAPTER 58 Acute Pancreatitis 903

a standard practice for patients who are thought to be at high an important to in the early management of AP (discussed later),
risk for pancreatitis after the procedure (see Box 58.5). PD stent several studies reported the beneficial effects of both types of fluid 58
placement is effective, presumably by preventing cannulation- in preventing PEP. The timing of such administration differed in
induced edema that can cause PD obstruction. The rationale studies, starting before the procedure or during the procedure
behind this is the spasm and edema of the ampulla after ERCP and continuing for variable period postprocedure, depending on
because of cannulation and cautery results in obstruction and AP. the PEP risk factors of the patient and the procedure per se. A
Several studies and meta-analysis confirmed the benefit of pro- systematic review of peri-procedural IV volume administration
phylactic pancreatic ductal stents in patients at high risk of post- concluded that there is some evidence to suggest that volume
ERCP pancreatitis. Prophylactic PD stents are either a 3 French administration affords protection against PEP, but study het-
or 5 French and can be less than 5 cm or greater than 5 cm in erogeneity precludes firm conclusions. 153 Adequately powered
length and placed temporarily to cover the 2- to 3-day period of randomized trials are needed to evaluate the preventive effect of
ampullary edema. More than 70% of the stents spontaneously periprocedural volume administration. Another systematic review
fell out within 3 to 4 days after providing an access for the bile reported that aggressive periprocedural volume administration
and pancreatic juice during the period of ampullary edema and with lactated Ringer solution can reduce the overall incidence
swelling. If a radiograph after a week suggests the stent has not of PEP, moderate to severe pancreatitis, and hyperamylasemia;
migrated, it needs to be removed endoscopically, usually before shorten the length of hospitalization; and reduce pain. 154 This
14 days. Stents left longer than that interval can cause chronic meta-analyses demonstrated many drawbacks in the studies using
ductal injury and hence the need for removal. A Swedish national intravenous volume administration in the perioperative period
registry data from 43,595 ERCP procedures showed that pancre- and particularly whether it has an added value in patients receiv-
atic stents with a diameter of >5 Fr and a length of >5 cm seems ing rectal NSAIDs. Furthermore, the cost-effectiveness of the
to have a better protective effect against post-ERCP pancreati- combined approach has not been investigated. To address these
tis, compared with shorter and thinner stents. 145 However, it is drawbacks, a randomized controlled adequately-powered trial is
not possible to determine the exact type of pancreatic stent (apart being planned to assess whether fluid administration schedule and
from material, length, and diameter) that has been introduced, so fluid type further reduce PEP in patients receiving prophylactic
their conclusion must be interpreted with caution. If post-ERCP rectal NSAIDs. 155 It is hoped that with the ongoing trials the role
pancreatitis is developing in patients who did not get a prophy- of prophylactic PD stents, rectal NSAID administration, peri-
lactic pancreatic stent or if the stent has migrated and the patient procedural fluid therapy, and combinations of these 3 modalities
is getting severe symptoms, urgent salvage ERCP with de novo will better define their role in preventing PEP.
pancreatic stent placement or replacement of a migrated stent
is a novel approach in the setting of early PEP, and was associ- Postoperative State
ated with rapid resolution of clinical pancreatitis and reduction
in serum levels of amylase and lipase. 146 Guidewire cannulation, Postoperative pancreatitis can occur after thoracic or abdomi-
whereby the biliary or PD is initially cannulated by a guidewire nal surgery. 156 Pancreatitis occurs after 0.4% to 7.6% of cardio-
inserted through the catheter or sphincterotome, has been shown pulmonary bypass operations. 125,157 Twenty-seven percent of
to decrease the risk of pancreatitis with comparable high levels patients undergoing cardiac surgery develop hyperamylasemia,
(∼98%) of cannulation success (see Box 58.5). 147 A meta-analysis and 1% develop necrotizing pancreatitis. 115 Significant risks for
of patients with difficult cannulation, sole use of the double guide pancreatitis after cardiopulmonary bypass are preoperative renal
wire technique appears to increase the risk of PEP without any insufficiency, postoperative hypotension, and administration of
superiority in achieving biliary cannulation compared with other calcium chloride perioperatively. Pancreatitis occurs after 6%
techniques. PD stenting may reduce the risk of PEP when the of liver transplantations. 158 Mortality from postoperative pan-
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DGT is used. The influence of co-intervention in the form of creatitis is said to be higher (up to 35%) than for other forms
peri-procedural NSAID administration is unclear. of pancreatitis. Contributors to morbidity and mortality from
In terms of attenuating the local inflammatory response, the postoperative pancreatitis are delay in diagnosis, hypotension,
most promising results have been seen with NSAIDs. A multi- medications (e.g., azathioprine/perioperative calcium chloride
center, double-blind, placebo-controlled, RCT of 602 patients administration), infections, and comorbidities. Postoperative
undergoing a high-risk ERCP demonstrated a significant reduc- pancreatitis should also be recognized as a pancreas specific com-
tion of PEP when patients were given rectal indomethacin after plication after pancreatic surgery. 159
the procedure. 148 There have been many studies published on the
type of NSAID (e.g., diclofenac vs. indomethacin) to adminis- Hereditary and Genetic Disorders
ter to high-risk patients as well as all patients undergoing ERCP
and the timing of such rectal administration (i.e., prior to the Hereditary pancreatitis, an autosomal dominant disorder with
procedure or after the procedure if the endoscopist feels there variable penetrance, is discussed in Chapter 57.
is a higher risk of PEP because of the nature of the procedure.
Two meta analyses concluded that rectal indomethacin is use- Miscellaneous Causes
ful only for high-risk patients, even when given before the pro-
cedure. 148,149 Another meta-analysis suggested pre-ERCP rectal AP has been rarely associated with Crohn disease. 160 A recent
indomethacin administration for all patients undergoing ERCP case-control study from Denmark found a 4-fold increase in
without risk of procedural bleeding, 150 and another showed ben- AP in patients with Crohn’s and a 1.5-fold increase in patients
efit with rectal indomethacin for all patients undergoing a ERCP with UC. This increase has been attributed by some to the use
with unclear timing with regards to the procedure. 151 The most of drugs such as 5-aminosalicylates/sulfasalazine and thiopurines
recent meta-analysis suggested a benefit of rectal NSAIDs for (azathioprine/6-mercaptopurine; see Box 58.4). Theories to sup-
all patients undergoing ERCP given before or after the proce- port a putative relationship between idiopathic IBD and pancre-
dure. 152 Thus, it appears that rectal administration of NSAIDs atitis include that pancreatitis is an extraintestinal manifestation
mostly indomethacin is definitely useful and probably can be of IBD, that duodenal Crohn disease can cause obstruction to
given to all patients undergoing ERCP before the procedure the flow of pancreatic juice, that granulomatous inflammation in
unless there are specific contraindications. Crohn’s can involve the pancreas, or that there is an associated
Extending the observation that intravenous volume adminis- autoimmune pancreatitis. A data base of patients with Crohn dis-
tration with normal saline or lactated Ringer solution has become ease from Alberta reported that 6.2% of patients who do were