Page 22 - Acute Pancreatitis (Viêm tụy cấp)

CHAPTER 58 Acute Pancreatitis 913

established infection. Necrosis of the pancreas and peripancreatic is a common observation that in mild (or interstitial) pancreatitis,
tissues (necrotizing pancreatitis) can become infected (infected most patients are dismissed from the hospital within 5 days. Two 58
pancreatic necrosis), with increased mortality. 291,292 The role of reports in patients with mild disease suggested that early refeed-
antibiotics in established infection of the pancreas or extrapan- ing improved outcome and allowed earlier discharge. 294,295 On
creatic sites is not controversial. Imipenem, fluoroquinolones the other hand, a meta-analysis of 3 studies showed that early
(ciprofloxacin, ofloxacin, pefloxacin), and metronidazole emerged refeeding prolonged the hospitalization. 296
as the drugs that achieved the highest inhibitory concentrations The question of whether an elevated serum amylase or lipase
in pancreatic tissue, However, their prophylactic role in pre- level should influence the clinician to prolong the time until
dicted moderately severe or severe AP or in established necro- refeeding has been addressed in one study: 116 patients with AP
tizing pancreatitis is where significant controversy exists. Most were fed at the clinician’s discretion, and 21% developed pain
recent guidelines do not recommend prophylactic antibiotics. 237 on refeeding 250 kcal/day. 297 If the serum lipase level was more
Future studies should have a large enough sample size to see than 3-fold elevated, clinical relapse rate with refeeding was 39%,
assess the benefit of prophylactic antibiotics in either predicted compared with 16% in those with a lipase <3-fold elevated. Nev-
moderately severe or severe or necrotizing pancreatitis. Particu- ertheless, most of the patients with 3-fold elevated serum lipase
lar subsets such as extensive necrosis with or without organ fail- levels did not have a recrudescence of their pain on refeeding.
ure should be assessed for possible benefit. Another meta-analysis reported that serum lipase levels of 2.5 fold
or higher are associated with oral feeding intolerance. 202 In order
Urgent ERCP to clarify the role of early feeding, there have been several trials in
these patients that compared various feeding recommendations,
The question of early removal of a possibly impacted gallstone in including NPO, clear liquid diet, soft diet, low-fat solid diet, and
improving the outcome of gallstone pancreatitis remains a con- full solid diet. Investigators also looked at starting feeding after
troversial issue. Because the obstruction by a stone at the level pancreatic enzymes normalize versus starting immediately.
of ampulla due to a stone is the main mechanism postulated in In mild AP, RCTs reported that it is possible to feed patients
acute biliary pancreatitis, it is appealing to remove the stone by immediately, 294 even with a full solid diet 295 without standard
ERCP to help the patient recover. ERCP in a patient with bili- practice of NPO initially, and others reporting that feeding can
ary pancreatitis can be urgent or elective before cholecystectomy. be with low fat solid diet versus clear liquids 296 or soft diet ver-
Urgent ERCP has been variously defined as within 24 hours, 48 sus clear liquids, 297 immediately without waiting for the pain to
hours, or 72 hours. For mild biliary AP, same-admission laparo- subside or the enzymes to normalize. Even in severe AP, patients
scopic cholecystectomy is the standard therapy, and before such who were fed early with low volume oral feeds had significantly
procedure an elective ERCP or intraoperative cholangiography less infection, need for intervention, and ICU and hospital stay. 298
are the choices. The most recent guidelines recommended urgent Based on 11 RCTs, an AGA technical review and AGA guide-
ERCP within 72 hours for cholangitis and possibly for persistent lines recommended early feeding (usually within 24 hours) for all
biliary obstruction defined by elevated liver tests and/or the pres- patients with AP (mild, moderately severe, and severe) as tolerated
ence of a stone in the common bile duct on imaging. 9,211 One by the patient. 94,135 However, if there is significant nausea and
report suggested that in acute biliary pancreatitis, urgent ERCP vomiting or ileus, then one may have to wait until they subside.
within 24 to 48 hours is indicated if the patient has cholangitis, In predicted severe and in established moderately severe,
total serum bilirubin >5 mg/dL, clinical deterioration (worsening severe and necrotizing pancreatitis as well as in some cases of
pain and white cell count and worsening vital signs), or a stone mild AP TPN has been studied with an intention to put the
documented in the common bile duct on imaging. 293 bowel to rest. The meta-analysis of 11 RCTs revealed increased
A recent AGA technical review reported a meta-analysis harm with TPN compared with enteral or oral feeding with
on 8 RCTs of urgent ERCP in acute biliary pancreatitis, com- regard to single and multiple organ failure and infected necro-
prising 935 patients. 237 This report found no benefit of urgent sis, 237 and AGA guidelines gave a strong recommendation based
ERCP in acute biliary pancreatitis with regard to single organ on moderate quality of evidence, which in AP enteral nutrition is
failure or multiple organ failure, infected peripancreatic necro- preferred to TPN if the patient is not able to tolerate oral feed-
sis, occurrence of necrotizing pancreatitis, or mortality. In the ing for prolonged period. 286 Thus currently TPN is indicated in
only study available with small number of cholangitis patients, AP in those who are not able to take oral diet for a long time and
there was no difference with urgent ERCP. Most recent stud- if enteral feeding is not possible or not tolerated. Even in estab-
ies try to exclude patients with proven cholangitis, as ERCP is lished necrotizing pancreatitis or predicted severe AP, it has been
the standard of care in those patients. However, the definition shown that it is possible to feed them orally very quickly without
and description of cholangitis varied among the studies, making the need for any artificial nutrition. Some reports suggested in
interpretation difficult. There was a slightly reduced hospital stay predicted severe or established necrotizing pancreatitis starting
with urgent ERCP. Hence one could cautiously conclude that the enteral nutrition early on, preferably in the first 24 hours, may
role of urgent ERCP in acute biliary pancreatitis is probably in be beneficial. However, an RCT did not support the superior-
those patients with cholangitis. In order to obtain good evidence, ity of such immediate enteral nutrition in predicted severe AP
the report suggested that future trials should be powered to see compared with on-demand enteral nutrition after 3 days. Thus
if urgent ERCP helps in subgroups like those with cholangitis, a diagnosis of moderately severe or severe AP usually takes 3 to
documented biliary obstruction, and predicted severe AP with 5 days to firmly establish, and at that time if oral feeding is not
clear definition for all the 3 subgroups. possible, nasogastric or nasojejunal feeding may be considered. 299
It is very clear that nasogastric and nasojejunal feeds are equally
Nutrition effective: a meta-analysis of 3 RCTs did not show any difference
between the 2 modalities of enteral nutrition. 237 However, there
For decades, keeping patients NPO was the rule in the manage- are many methodological problems in these trials, and in one trial
ment of patients with AP. However, fasting adversely affects the nasojejunal route was actually postpyloric feeding. There are
the gut mucosal barrier and facilitates translocation of bacteria some theoretical advantages of nasojejunal feeding, particularly
from the lumen of the gut to extraluminal tissues, including the in that it provides more rest to the pancreas via the ileal break
inflamed pancreas, with a resultant increase in morbidity and mechanism. Hence at this time the current guidelines recom-
mortality. Thus the concept of gut rousing by nutrition and not mend either nasogastric or nasojejunal feeding for patients with
gut resting by fasting became the practice in some centers. 277 It AP if oral intake is not possible for prolonged periods.