Reactions to Contrast Media (CM) Administered at the Time of the Endoscopic Retrograde Cholangiopancreatography (ERCP)

The aim of this study is to prospectively document the incidence of CM adverse reactions at
the time of ERCP and to determine whether various perceived risk factors are predictive of
adverse reaction.

Adverse reactions to iodine containing contrast media (CM) have been described after
endoscopic retrograde cholangiopancreaticography (ERCP) but have been difficult to study due
to their extremely low incidence. Adverse reactions can be classified by severity (mild,
moderate or severe) or underlying mechanism (idiosyncratic versus nonidiosyncratic).
Nonidiosyncratic reactions are related to the dose and osmolality of the CM; these are not
observed during ERCP due to the relative small amount of systemic absorption of CM.
Idiosyncratic reactions on the other hand are not dose-dependent and generally occur shortly
after administration of CM.

Premedication with corticosteroids, H1/H2 -blockers and the use of low osmolality CM is
beneficial in preventing nonidiosyncratic reactions during intravascular administration.
However their role in during ERCP is unclear as CM is not injected into the intravascular
space. Currently there are no formal recommendations and clinical practice varies
considerably. The general purpose of this study is to determine the incidence of CM
reactions during ERCP and to determine whether various risk factors are predictive of
idiosyncratic reactions. Based on these results, we hope to develop guidelines for the use
of prophylaxis to prevent CM reactions in ERCP.