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Prospective evaluation of adverse reactions to iodine-containing contrast media after ERCP
ORIGINAL ARTICLE: Clinical Endoscopy
Prospective evaluation of adverse reactions to iodine-containing contrast media after ERCP Peter V. Draganov, MD, Chris E. Forsmark, MD Gainesville, Florida, USA
Background: The incidence of contrast media reactions administered at the time of ERCP is unknown. Despite the lack of formal recommendations, numerous types of prophylactic regimens are routinely used in patients with a history of prior reactions to intravascular contrast media. Objective: Our purpose was to document the incidence of contrast media reactions at the time of ERCP and to determine whether various perceived risk factors are predictive of adverse reactions. Design: Prospective study. Setting: Tertiary academic center. Patients: A total of 601 patients undergoing ERCP as clinically indicated. Interventions: ERCP done with full-strength high osmolality contrast media. No prophylactic medications were given to any patient. Main Outcome Measurements: Adverse reactions to contrast media. Results: Six hundred one patients were enrolled. Eighty patients had prior documented reactions to intravascular contrast media (39 mild, 21 moderate, 20 severe). Of the 80 patients, 15 additionally reported shellfish allergy, and 46 reported allergic diathesis. Of the 521 patients with no prior reaction to intravascular contrast, 215 reported other history of allergic reaction. Forty-nine were allergic to shellfish, and 166 had underlying allergic diathesis. At ERCP, 277 patients had cholangiograms, 48 pancreatograms, and 276 both. The average volume of contrast per ERCP was 22 mL. No adverse reactions associated with the administration of contrast media at the time of ERCP were observed in any of the patients. Conclusions: The incidence of adverse reaction to iodine-containing contrast media administered at the time of ERCP even in patients considered to be at high risk is exceedingly low. The use of prophylactic regimens before ERCP appears to be unnecessary. (Gastrointest Endosc 2008;68:1098-101.)
Systemic adverse reactions to iodine-containing contrast media (CM) used during ERCP have been reported.1-3 Systemic absorption of CM after ERCP routinely occurs, but the adverse reaction rate appears to be very low. The exact incidence remains unknown because of the retrospective nature of all reports. Significantly, the American Society for Gastrointestinal Endoscopy technology status evaluation report on radiographic CM used in ERCP states that ‘‘there are no evidence-based standards of practice for prophylaxis against CM reactions during the performance of ERCP.’’4 Despite
the lack of formal recommendations for any type of prophylaxis in patients with a history of reaction to intravascular CM, numerous prophylactic regimens are routinely used.5 More significantly, the use of prophylaxis has even expanded to patients with no prior reaction to intravascular CM but who are somehow perceived to be at increased risk (eg, shellfish allergy).5 The aim of this study was 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 reactions.
Abbreviation: CM, contrast media.
METHODS
Copyright ª 2008 by the American Society for Gastrointestinal Endoscopy 0016-5107/$34.00 doi:10.1016/j.gie.2008.07.031
This prospective study was approved by the University of Florida Institutional Review Board. All patients signed
1098 GASTROINTESTINAL ENDOSCOPY Volume 68, No. 6 : 2008
www.giejournal.org
Draganov & Forsmark
research study informed consent. All patients undergoing ERCP at our institution were considered for the study. Exclusion criteria were age less than 18 years and the patient unable or unwilling to consent to the study. Before the ERCP, previous adverse reactions to intravascular CM and other factors thought to be associated with an increased risk for reactions were recorded (Table 1).6,7 Attention was focused to record only well-established unequivocal prior reactions to CM. For the purpose of this study, feelings of warmth, flushing, altered taste, or anxiety after intravascular administration of CM were not classified as prior adverse reactions. Allergic diathesis was defined when one or more of the following was present: asthma, urticaria, allergy to insect bites, pollen allergy, shellfish allergy, food allergies (other than shellfish), and drug allergies. The severity of prior reactions was graded as mild, moderate, or severe on the basis of an accepted consensus classification (Table 2).7,8 The ERCP was done as clinically indicated with use of full-strength, ionic, high-osmolality CM (iothalamate meglumine, Tyco Healthcare, St Louis, Mo). No prophylactic medications were given to any patient before the procedure. The volume of CM used at the time of ERCP and the opacified duct(s) were recorded. The patients were monitored for occurrence of adverse reaction to CM from initiation of the ERCP until discharge from our endoscopy unit (2 hours after ERCP completion). All data were prospectively entered into a research database specifically created for this study. Sample size calculation was done with the Fisher exact test (a Z .05, power Z 0.8).
RESULTS From March 2002 to December 2006, 3192 patients underwent ERCP at our unit. During the same time period, 602 patients were approached to participate in the study. Particular attention was paid to enroll patients with some perceived risk factor for adverse reactions to contrast media (Table 1). One patient with a prior mild reaction to CM declined to participate because she was told to never have exposure to CM without prophylaxis. The remaining 601 patients were enrolled in the study, and the results are reported in this article. This sample size gives us the power to detect a CM adverse reaction rate of 1.6% in our study group. Three hundred twenty-seven subjects were female, and 274 were male. The average age was 56 years (range 18-92 years). Potential risk factors for reactions to CM in our patient population are presented in Figure 1. Eighty patients had a prior documented reaction to intravascular CM (39 mild, 21 moderate, 20 severe). Of the 80 patients with prior adverse reactions to CM, 15 additionally reported shellfish allergy and 46 also reported allergic diathesis. Of the 521 patients with no prior reactions to intravascular CM, 215 reported some other history of allergic reaction. Forty-nine were allergic to shellfish, and 166 www.giejournal.org
Adverse reactions to iodine-containing contrast media after ERCP
Capsule Summary What is already known on this topic d
Numerous prophylactic regimens are used routinely in patients with a history of prior reactions to intravascular contrast media.
What this study adds to our knowledge d
In a prospective study of 601 patients undergoing ERCP with full-strength high-osmolality contrast agent, no adverse reaction occurred, even in those considered to be at high risk because of previous allergic reactions.
had an underlying allergic diathesis. At the time of the ERCP, 277 patients had only a cholangiogram, 48 only a pancreatogram, and 276 had both. None of the patients was taking corticosteroids for unrelated indications at the time of ERCP. The average volume of CM used per ERCP was 22 mL (range 1-110 mL). For the 80 patients with prior adverse reactions, the average volume on CM was 17 mL (range 1-58 mL) and for the remaining 521 patients 23 mL (range 1-110 mL) (not significant). No adverse reactions associated with the administration of CM at the time of ERCP or in follow-up in our recovery room were observed in any of the study patients.
DISCUSSION Significantly, our study found that the incidence of adverse reactions to iodine-containing CM administered at the time of ERCP were exceedingly low. Not a single adverse reaction was observed after 601 ERCPs done with no prophylaxis with full-strength ionic high-osmolarity CM. The strengths of our study are the following: (1) prospective design, (2) extensive preprocedure screening for various potential risk factors for reactions to CM, (3) patients categorized as having a prior adverse reaction to CM only when the reaction appeared to be well established and unequivocal, (4) large study population with varying degree of risk for adverse reactions, and (5) large number of patients perceived to be at the highest risk for adverse reactions (those with prior reactions to intravascular CM). Systemic absorption of CM after ERCP is well documented.9-14 Urographic visualization of contrast has been observed on plain films after ERCP in up to 37% of cases.12,14 CT scanning detected renal excretion of CM in 69% of patients.10 The serum concentration of CM increased significantly in 76% of patients after ERCP.13 In another study, Mann et al9 measured serum iodine concentration before and after ERCP. A highly significant increase was seen in all patients, but this was substantially lower (100 times) than what is found with intravenous administration of the same amount of contrast. Despite Volume 68, No. 6 : 2008 GASTROINTESTINAL ENDOSCOPY 1099
Adverse reactions to iodine-containing contrast media after ERCP
TABLE 1. Factors thought to be associated with increased risk for reaction to contrast media recorded before ERCP
Draganov & Forsmark
TABLE 2. Categories of adverse reactions to contrast media on the basis of severity Mild
Prior adverse reaction to intravascular contrast media
Moderate
Severe
Nausea/vomiting
Tachycardia/ vradycardia
Severe laryngeal edema
Headache
Hypertension
Seizures
Dizziness
Mild hypotension
Severe hypotension/ shock
Pollen allergy
Shaking/chills
Dyspnea
Arrhythmias
Shellfish allergy
Itching
Bronchospasm/ wheezing
Cardiac arrest
Sweats
Mild laryngeal edema
Respiratory arrest
Rash/hives
Pronounced urticaria
Asthma Urticaria Allergy to insect bites
Food allergies (other than shellfish) Drug allergies
systemic absorption of CM routinely occurring after ERCP, it is surprising that the adverse reaction rate is so exceedingly low. Because the exact mechanism of adverse reactions to CM remains elusive, it is difficult to explain this discrepancy. In all likelihood, the risk of an allergic reaction to CM administered at the time of ERCP is low because of the slow rate of absorption of CM from the biliary tree, pancreas, and small bowel. It is noteworthy that in the 2591 patients who underwent ERCP during the study period but who were not part of the study, no allergic reactions to CM were seen. The current clinical practices of premedication or substitution for low osmolality CM in patients perceived to be at high risk for CM reactions administered at the time of ERCP (ie, those with a prior reaction to intravascular CM) are based purely on theoretic considerations.4 Despite the lack of any clinical data to support these practices, 83% of physicians routinely use some form of prophylaxis in patients perceived to be at high risk.5 As noted earlier, this use of prophylaxis has even expanded to patients with no prior reaction to intravascular CM but still somehow perceived to be at increased risk (eg, shellfish allergy).5 Moreover, this unnecessary use of prophylactic regimens has a number of drawbacks. First, there is direct cost associated with the medications used for prophylaxis (steroids, histamine-1 blockers, histamine-2 blockers). Second, the cost of low osmolality CM ($35 to $55 per 50-mL bottle) is substantially higher than standard high osmolality CM ($3 to $7 per 50-mL bottle).4 Third, the patient procedure can be canceled or delayed. If an ‘‘allergy’’ to CM is recognized immediately before the procedure, 20% of physicians will postpone the ERCP until the following day and give a 12-hour prophylactic steroid regimen.5 Surprisingly, 73% will delay the procedure for few hours and use an intravenous steroid as a prophylaxis 1 hour before the ERCP, despite the observation that this regimen is ineffective in decreasing 1100 GASTROINTESTINAL ENDOSCOPY Volume 68, No. 6 : 2008
Swelling of eyes, face Mild urticaria All reactions were graded as mild, moderate, or severe as per Table 2.
the rate of adverse reactions after intravascular CM administration.7,14 On the basis of the results of our study, the use of prophylactic regimens before ERCP appears to be unnecessary. Our study is not without limitations. Despite taking care to categorize patients as having a prior adverse reaction to CM only when the reaction appeared to be well established, it is still possible that a patient may have been misclassified or that the prior adverse reaction was to another medication (eg, sedation medication) that was administered concomitantly with the intravenous contrast. Furthermore, a particular challenge is that, despite enrolling a large number of patients and seeing no adverse reactions even in individuals perceived to be at high risk, it cannot be concluded that an adverse reaction will never occur after CM administration at the time of ERCP. From that perspective, our everyday practice is to do all ERCPs with no prophylactic therapy for contrast allergy but to always ensure that emergency therapy is immediately available. In conclusion, the incidence of adverse reactions to iodine-containing contrast media administered at the time of ERCP, even in patients considered to be at high risk, is exceedingly low. The use of prophylactic regimens before ERCP appears to be unnecessary, and their use appears to increase cost without any measurable increase in safety. DISCLOSURE The authors report that there are no disclosures relevant to this publication. www.giejournal.org
Draganov & Forsmark
Adverse reactions to iodine-containing contrast media after ERCP
Figure 1. Study patients’ potential risk factors for adverse reactions to contrast media.
REFERENCES 1. Moreira VF, Meron˜o E, Larraona JL, et al. ERCP and allergic reactions to iodized contrast media. Gastrointest Endosc 1985;31:293. 2. Bilbao MK, Dotter CT, Lee TG, et al. Complications of endoscopic retrograde cholangiopancreatography (ERCP): a study of 10,000 cases. Gastroenterology 1976;70:314-20. 3. Lorenz R. Allergic reaction to contrast medium after endoscopic retrograde pancreatography. Endoscopy 1990;22:196. 4. Mishkin D, Carpenter S, Croffie J, et al. ASGE technology status evaluation report: radiographic contrast media used in ERCP. Gastrointest Endosc 2005;62:480-4. 5. Draganov P, Cotton PB. Iodinated contrast sensitivity in ERCP. Am J Gastroenterol 2000;95:1398-401. 6. Simon MR. Allergic-type adverse reactions to low osmolality contrast media in patients with a history of allergy or asthma. Invest Radiol 1995;30:285-90. 7. American College of Radiology Committee on Drugs and Contrast Media. Manual on contrast media. 5.0 ed, Reston, VA: The College; 2004. 8. Morcos SK, Thomsen HS. Adverse reactions to iodinated contrast media. Eur Radiol 2001;11:1267-75.
www.giejournal.org
9. Mann K, Rendl J, Busley R, et al. Systemic iodine absorption during endoscopic application of radiographic contrast agents for endoscopic retrograde cholangiopancreaticography. Eur J Endocrinol 1994;130:498-501. 10. Hopper KD, Wegert SJ, Hallgren SE. Renal excretion of endoscopic retrograde cholangiopancreatography injected contrast: a common phenomenon. Invest Radiol 1989;24:394-6. 11. Ladas SD, Rokkas T, Kaskarelis J, et al. Absorption of iodized contrast media during ERCP. Gastrointest Endosc 1986;32:376. 12. Roszler MH, Campbell WL. Post-ERCP pancreatitis: association with urographic visualization during ERCP. Radiology 1985;157:595-8. 13. Sable RA, Rosenthal WS, Siegel J, et al. Absorption of contrast medium during ERCP. Dig Dis Sci 1983;28:801-6. 14. Sahel J, Sarles H. Endoscopic pancreatography and urograms. Gastroenterology 1976;71:1109.
Received April 23, 2008. Accepted July 19, 2008. Current affiliations: University of Florida, Gainesville, Florida, USA. Reprint requests: Peter V. Draganov, University of Florida, Division of Gastroenterology, Hepatology, and Nutrition, 1600 SW Archer Rd, Room HD 602, PO Box 100214, Gainesville, FL 32610.
Volume 68, No. 6 : 2008 GASTROINTESTINAL ENDOSCOPY 1101
Prospective evaluation of adverse reactions to iodine-containing contrast media after ERCP Peter V. Draganov, MD, Chris E. Forsmark, MD Gainesville, Florida, USA
Background: The incidence of contrast media reactions administered at the time of ERCP is unknown. Despite the lack of formal recommendations, numerous types of prophylactic regimens are routinely used in patients with a history of prior reactions to intravascular contrast media. Objective: Our purpose was to document the incidence of contrast media reactions at the time of ERCP and to determine whether various perceived risk factors are predictive of adverse reactions. Design: Prospective study. Setting: Tertiary academic center. Patients: A total of 601 patients undergoing ERCP as clinically indicated. Interventions: ERCP done with full-strength high osmolality contrast media. No prophylactic medications were given to any patient. Main Outcome Measurements: Adverse reactions to contrast media. Results: Six hundred one patients were enrolled. Eighty patients had prior documented reactions to intravascular contrast media (39 mild, 21 moderate, 20 severe). Of the 80 patients, 15 additionally reported shellfish allergy, and 46 reported allergic diathesis. Of the 521 patients with no prior reaction to intravascular contrast, 215 reported other history of allergic reaction. Forty-nine were allergic to shellfish, and 166 had underlying allergic diathesis. At ERCP, 277 patients had cholangiograms, 48 pancreatograms, and 276 both. The average volume of contrast per ERCP was 22 mL. No adverse reactions associated with the administration of contrast media at the time of ERCP were observed in any of the patients. Conclusions: The incidence of adverse reaction to iodine-containing contrast media administered at the time of ERCP even in patients considered to be at high risk is exceedingly low. The use of prophylactic regimens before ERCP appears to be unnecessary. (Gastrointest Endosc 2008;68:1098-101.)
Systemic adverse reactions to iodine-containing contrast media (CM) used during ERCP have been reported.1-3 Systemic absorption of CM after ERCP routinely occurs, but the adverse reaction rate appears to be very low. The exact incidence remains unknown because of the retrospective nature of all reports. Significantly, the American Society for Gastrointestinal Endoscopy technology status evaluation report on radiographic CM used in ERCP states that ‘‘there are no evidence-based standards of practice for prophylaxis against CM reactions during the performance of ERCP.’’4 Despite
the lack of formal recommendations for any type of prophylaxis in patients with a history of reaction to intravascular CM, numerous prophylactic regimens are routinely used.5 More significantly, the use of prophylaxis has even expanded to patients with no prior reaction to intravascular CM but who are somehow perceived to be at increased risk (eg, shellfish allergy).5 The aim of this study was 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 reactions.
Abbreviation: CM, contrast media.
METHODS
Copyright ª 2008 by the American Society for Gastrointestinal Endoscopy 0016-5107/$34.00 doi:10.1016/j.gie.2008.07.031
This prospective study was approved by the University of Florida Institutional Review Board. All patients signed
1098 GASTROINTESTINAL ENDOSCOPY Volume 68, No. 6 : 2008
www.giejournal.org
Draganov & Forsmark
research study informed consent. All patients undergoing ERCP at our institution were considered for the study. Exclusion criteria were age less than 18 years and the patient unable or unwilling to consent to the study. Before the ERCP, previous adverse reactions to intravascular CM and other factors thought to be associated with an increased risk for reactions were recorded (Table 1).6,7 Attention was focused to record only well-established unequivocal prior reactions to CM. For the purpose of this study, feelings of warmth, flushing, altered taste, or anxiety after intravascular administration of CM were not classified as prior adverse reactions. Allergic diathesis was defined when one or more of the following was present: asthma, urticaria, allergy to insect bites, pollen allergy, shellfish allergy, food allergies (other than shellfish), and drug allergies. The severity of prior reactions was graded as mild, moderate, or severe on the basis of an accepted consensus classification (Table 2).7,8 The ERCP was done as clinically indicated with use of full-strength, ionic, high-osmolality CM (iothalamate meglumine, Tyco Healthcare, St Louis, Mo). No prophylactic medications were given to any patient before the procedure. The volume of CM used at the time of ERCP and the opacified duct(s) were recorded. The patients were monitored for occurrence of adverse reaction to CM from initiation of the ERCP until discharge from our endoscopy unit (2 hours after ERCP completion). All data were prospectively entered into a research database specifically created for this study. Sample size calculation was done with the Fisher exact test (a Z .05, power Z 0.8).
RESULTS From March 2002 to December 2006, 3192 patients underwent ERCP at our unit. During the same time period, 602 patients were approached to participate in the study. Particular attention was paid to enroll patients with some perceived risk factor for adverse reactions to contrast media (Table 1). One patient with a prior mild reaction to CM declined to participate because she was told to never have exposure to CM without prophylaxis. The remaining 601 patients were enrolled in the study, and the results are reported in this article. This sample size gives us the power to detect a CM adverse reaction rate of 1.6% in our study group. Three hundred twenty-seven subjects were female, and 274 were male. The average age was 56 years (range 18-92 years). Potential risk factors for reactions to CM in our patient population are presented in Figure 1. Eighty patients had a prior documented reaction to intravascular CM (39 mild, 21 moderate, 20 severe). Of the 80 patients with prior adverse reactions to CM, 15 additionally reported shellfish allergy and 46 also reported allergic diathesis. Of the 521 patients with no prior reactions to intravascular CM, 215 reported some other history of allergic reaction. Forty-nine were allergic to shellfish, and 166 www.giejournal.org
Adverse reactions to iodine-containing contrast media after ERCP
Capsule Summary What is already known on this topic d
Numerous prophylactic regimens are used routinely in patients with a history of prior reactions to intravascular contrast media.
What this study adds to our knowledge d
In a prospective study of 601 patients undergoing ERCP with full-strength high-osmolality contrast agent, no adverse reaction occurred, even in those considered to be at high risk because of previous allergic reactions.
had an underlying allergic diathesis. At the time of the ERCP, 277 patients had only a cholangiogram, 48 only a pancreatogram, and 276 had both. None of the patients was taking corticosteroids for unrelated indications at the time of ERCP. The average volume of CM used per ERCP was 22 mL (range 1-110 mL). For the 80 patients with prior adverse reactions, the average volume on CM was 17 mL (range 1-58 mL) and for the remaining 521 patients 23 mL (range 1-110 mL) (not significant). No adverse reactions associated with the administration of CM at the time of ERCP or in follow-up in our recovery room were observed in any of the study patients.
DISCUSSION Significantly, our study found that the incidence of adverse reactions to iodine-containing CM administered at the time of ERCP were exceedingly low. Not a single adverse reaction was observed after 601 ERCPs done with no prophylaxis with full-strength ionic high-osmolarity CM. The strengths of our study are the following: (1) prospective design, (2) extensive preprocedure screening for various potential risk factors for reactions to CM, (3) patients categorized as having a prior adverse reaction to CM only when the reaction appeared to be well established and unequivocal, (4) large study population with varying degree of risk for adverse reactions, and (5) large number of patients perceived to be at the highest risk for adverse reactions (those with prior reactions to intravascular CM). Systemic absorption of CM after ERCP is well documented.9-14 Urographic visualization of contrast has been observed on plain films after ERCP in up to 37% of cases.12,14 CT scanning detected renal excretion of CM in 69% of patients.10 The serum concentration of CM increased significantly in 76% of patients after ERCP.13 In another study, Mann et al9 measured serum iodine concentration before and after ERCP. A highly significant increase was seen in all patients, but this was substantially lower (100 times) than what is found with intravenous administration of the same amount of contrast. Despite Volume 68, No. 6 : 2008 GASTROINTESTINAL ENDOSCOPY 1099
Adverse reactions to iodine-containing contrast media after ERCP
TABLE 1. Factors thought to be associated with increased risk for reaction to contrast media recorded before ERCP
Draganov & Forsmark
TABLE 2. Categories of adverse reactions to contrast media on the basis of severity Mild
Prior adverse reaction to intravascular contrast media
Moderate
Severe
Nausea/vomiting
Tachycardia/ vradycardia
Severe laryngeal edema
Headache
Hypertension
Seizures
Dizziness
Mild hypotension
Severe hypotension/ shock
Pollen allergy
Shaking/chills
Dyspnea
Arrhythmias
Shellfish allergy
Itching
Bronchospasm/ wheezing
Cardiac arrest
Sweats
Mild laryngeal edema
Respiratory arrest
Rash/hives
Pronounced urticaria
Asthma Urticaria Allergy to insect bites
Food allergies (other than shellfish) Drug allergies
systemic absorption of CM routinely occurring after ERCP, it is surprising that the adverse reaction rate is so exceedingly low. Because the exact mechanism of adverse reactions to CM remains elusive, it is difficult to explain this discrepancy. In all likelihood, the risk of an allergic reaction to CM administered at the time of ERCP is low because of the slow rate of absorption of CM from the biliary tree, pancreas, and small bowel. It is noteworthy that in the 2591 patients who underwent ERCP during the study period but who were not part of the study, no allergic reactions to CM were seen. The current clinical practices of premedication or substitution for low osmolality CM in patients perceived to be at high risk for CM reactions administered at the time of ERCP (ie, those with a prior reaction to intravascular CM) are based purely on theoretic considerations.4 Despite the lack of any clinical data to support these practices, 83% of physicians routinely use some form of prophylaxis in patients perceived to be at high risk.5 As noted earlier, this use of prophylaxis has even expanded to patients with no prior reaction to intravascular CM but still somehow perceived to be at increased risk (eg, shellfish allergy).5 Moreover, this unnecessary use of prophylactic regimens has a number of drawbacks. First, there is direct cost associated with the medications used for prophylaxis (steroids, histamine-1 blockers, histamine-2 blockers). Second, the cost of low osmolality CM ($35 to $55 per 50-mL bottle) is substantially higher than standard high osmolality CM ($3 to $7 per 50-mL bottle).4 Third, the patient procedure can be canceled or delayed. If an ‘‘allergy’’ to CM is recognized immediately before the procedure, 20% of physicians will postpone the ERCP until the following day and give a 12-hour prophylactic steroid regimen.5 Surprisingly, 73% will delay the procedure for few hours and use an intravenous steroid as a prophylaxis 1 hour before the ERCP, despite the observation that this regimen is ineffective in decreasing 1100 GASTROINTESTINAL ENDOSCOPY Volume 68, No. 6 : 2008
Swelling of eyes, face Mild urticaria All reactions were graded as mild, moderate, or severe as per Table 2.
the rate of adverse reactions after intravascular CM administration.7,14 On the basis of the results of our study, the use of prophylactic regimens before ERCP appears to be unnecessary. Our study is not without limitations. Despite taking care to categorize patients as having a prior adverse reaction to CM only when the reaction appeared to be well established, it is still possible that a patient may have been misclassified or that the prior adverse reaction was to another medication (eg, sedation medication) that was administered concomitantly with the intravenous contrast. Furthermore, a particular challenge is that, despite enrolling a large number of patients and seeing no adverse reactions even in individuals perceived to be at high risk, it cannot be concluded that an adverse reaction will never occur after CM administration at the time of ERCP. From that perspective, our everyday practice is to do all ERCPs with no prophylactic therapy for contrast allergy but to always ensure that emergency therapy is immediately available. In conclusion, the incidence of adverse reactions to iodine-containing contrast media administered at the time of ERCP, even in patients considered to be at high risk, is exceedingly low. The use of prophylactic regimens before ERCP appears to be unnecessary, and their use appears to increase cost without any measurable increase in safety. DISCLOSURE The authors report that there are no disclosures relevant to this publication. www.giejournal.org
Draganov & Forsmark
Adverse reactions to iodine-containing contrast media after ERCP
Figure 1. Study patients’ potential risk factors for adverse reactions to contrast media.
REFERENCES 1. Moreira VF, Meron˜o E, Larraona JL, et al. ERCP and allergic reactions to iodized contrast media. Gastrointest Endosc 1985;31:293. 2. Bilbao MK, Dotter CT, Lee TG, et al. Complications of endoscopic retrograde cholangiopancreatography (ERCP): a study of 10,000 cases. Gastroenterology 1976;70:314-20. 3. Lorenz R. Allergic reaction to contrast medium after endoscopic retrograde pancreatography. Endoscopy 1990;22:196. 4. Mishkin D, Carpenter S, Croffie J, et al. ASGE technology status evaluation report: radiographic contrast media used in ERCP. Gastrointest Endosc 2005;62:480-4. 5. Draganov P, Cotton PB. Iodinated contrast sensitivity in ERCP. Am J Gastroenterol 2000;95:1398-401. 6. Simon MR. Allergic-type adverse reactions to low osmolality contrast media in patients with a history of allergy or asthma. Invest Radiol 1995;30:285-90. 7. American College of Radiology Committee on Drugs and Contrast Media. Manual on contrast media. 5.0 ed, Reston, VA: The College; 2004. 8. Morcos SK, Thomsen HS. Adverse reactions to iodinated contrast media. Eur Radiol 2001;11:1267-75.
www.giejournal.org
9. Mann K, Rendl J, Busley R, et al. Systemic iodine absorption during endoscopic application of radiographic contrast agents for endoscopic retrograde cholangiopancreaticography. Eur J Endocrinol 1994;130:498-501. 10. Hopper KD, Wegert SJ, Hallgren SE. Renal excretion of endoscopic retrograde cholangiopancreatography injected contrast: a common phenomenon. Invest Radiol 1989;24:394-6. 11. Ladas SD, Rokkas T, Kaskarelis J, et al. Absorption of iodized contrast media during ERCP. Gastrointest Endosc 1986;32:376. 12. Roszler MH, Campbell WL. Post-ERCP pancreatitis: association with urographic visualization during ERCP. Radiology 1985;157:595-8. 13. Sable RA, Rosenthal WS, Siegel J, et al. Absorption of contrast medium during ERCP. Dig Dis Sci 1983;28:801-6. 14. Sahel J, Sarles H. Endoscopic pancreatography and urograms. Gastroenterology 1976;71:1109.
Received April 23, 2008. Accepted July 19, 2008. Current affiliations: University of Florida, Gainesville, Florida, USA. Reprint requests: Peter V. Draganov, University of Florida, Division of Gastroenterology, Hepatology, and Nutrition, 1600 SW Archer Rd, Room HD 602, PO Box 100214, Gainesville, FL 32610.
Volume 68, No. 6 : 2008 GASTROINTESTINAL ENDOSCOPY 1101