Oliver W. Cass

A comparison of nonionic versus ionic contrast media : results of a prospective, multicenter study

BACKGROUND Pancreatitis is one of the most common complications associated with ERCP. Multiple factors have been implicated for this potentially serious complication. Numerous suggestions for minimizing risks at ERCP have been offered, one of which is to use nonionic, low osmolarity contrast agents for pancreatic injection. Results of previous studies comparing different contrast media have been inconclusive. METHODS To evaluate the role contrast material plays in the development of post-ERCP pancreatitis, the Midwest Pancreaticobiliary Group performed a prospective double-blind controlled study. A total of 1,979 consecutive ERCP patients were enrolled, and 1,659 patients with pancreatic duct injections were divided into subgroups according to the complexity of the ERCP. Post-ERCP pancreatitis was compared between similar groups. Patients were randomized to receive injections of nonionic, low osmolarity contrast or standard ionic contrast media. RESULTS The overall incidence of post-procedural pancreatitis was 10.2%. Those with diagnostic ERCP had the lowest incidence at 5.6%. Therapeutic procedures (12.3%) and sphincter of Oddi manometry (15.2%) had higher rates. Those injected with standard (ionic) contrast had an incidence of 10.4% and after injection with lower osmolar (nonionic) contrast, there was a 10% post-procedural pancreatitis rate. CONCLUSIONS Patients with more complex procedures develop pancreatitis more frequently. The use of low osmolar (nonionic) contrast media does not decrease the incidence of post-ERCP pancreatitis.

Evaluation of post-ERCP pancreatitis: potential causes noted during controlled study of differing contrast media

BACKGROUND Possible sources of post-ERCP pancreatitis were evaluated during a prospective, randomized, controlled study comparing different contrast media. METHODS A total of 1979 patients were randomized and subdivided into groups during the study. Patients were grouped for comparison depending on the type of procedure performed during ERCP. Diagnostic patients studied with pancreatograms (Group I) were compared with other groups, specifically, those not studied with pancreatograms (Group IV). All patients had subjective and objective estimates of the difficulty in cannulation of both ducts. The incidence of postprocedural pancreatitis was compared between and within each group. RESULTS In Group I there was a progressively higher incidence of pancreatitis with increased numbers of pancreatic duct injections. Patients with the highest (19.5%) frequency of pancreatitis received 10 or more injections into the pancreatic duct. Group I cases with difficult common bile duct cannulations had a higher frequency of post-ERCP pancreatitis (9.5%), as compared with the entire group (5.6%). CONCLUSIONS There was a higher incidence of pancreatitis associated with increased manipulation around the papillary orifice, especially with multiple pancreatic duct injections. There was also a slightly higher incidence of post-ERCP pancreatitis in cases with difficult common bile duct cannulation. Endoscopists are encouraged to evaluate and develop safer cannulation techniques that minimize the number of injections into the pancreatic duct and enhance selective cannulation.

Carbon dioxide retention and oxygen desaturation during gastrointestinal endoscopy

BACKGROUND Pulse oximetry measures arterial oxygen saturation (SpO2), not hypoventilation, which is directly reflected by increases in carbon dioxide tension. METHODS In the present study, transcutaneous carbon dioxide tension (PtcCO2) and SpO2 were measured during 101 endoscopic procedures selected for long duration or comorbid illnesses, and relationships between hypercapnia and hypoxemia were evaluated. Nasal oxygen was administered only for sustained desaturation (SpO2 < 90%). RESULTS Mean peak increase in PtcCO2 was significantly higher in patients requiring oxygen for sustained desaturation (16.3 mm Hg; range, 4-52) than in patients breathing room air who had transient or no desaturation (10.2 mm Hg [range, 3-19] and 5.1 mm Hg [range, 0-15]). If nasal oxygen corrected desaturation, even transient recurrence of desaturation indicated worsening CO2 retention, which preceded respiratory arrest in one patient. Independent predictors of hypercapnia were fentanyl and midazolam doses, oxygen requirement, and dementia. CONCLUSIONS Severe hypoventilation may occur during endoscopy, undetected by clinical observation or pulse oximetry, but only in sedated patients who require supplemental oxygen to maintain SpO2 above 90%. After oxygen supplementation corrects desaturation, recurrence of desaturation implies severe hypoventilation and warrants limitation of further sedation.

Fluoroscopy is not necessary for Maloney dilation of chronic esophageal strictures.

The use of fluoroscopic guidance for Maloney dilation is controversial. In order to determine if fluoroscopic analysis would enhance the success of dilation and increase recognition of adverse events, we prospectively studied 125 Maloney dilations in 80 patients (mean age, 69.3 years) with mild esophageal strictures. Most strictures (89%) resulted from acid-peptic disease. Operators included two staff physicians (5 and 25 years of experience) and one trainee (1 year of experience). Dilations were performed with the patient seated upright and the operator noting the presence and amount of resistance (dilator size, 36F to 60F; median, 50F). The fluoroscopic monitor was not visible to the operator, and the results were recorded by an observer who did not communicate with the operator. Operator assessment of Maloney dilation was correct in 122 of 125 procedures. Two failures were interpreted as no passage by the operator when passage had occurred as confirmed by fluoroscopy. One failure was interpreted as passage when no passage had occurred as indicated by fluoroscopy. Adverse events included 1 episode of tracheal intubation and failure to recognize the dilator tip curling in the esophagus as observed by fluoroscopy in 6 of 125 (4.8%) procedures. Operator assessment of resistance was more often associated with curling of the dilator on the greater curve of the stomach than with an esophageal stricture. Greater operator experience tended to correlate with increased success and correct interpretation of dilation. Maloney dilations performed with patients at 30 degrees rather than upright at 90 degrees were associated with a marked increase in unsuccessful dilator passage and curling of dilator tip.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatolithiasis and Cholangiocarcinoma in Cystic Fibrosis: A Case Series and Review of the Literature

Advancements in the pulmonary and infectious disease management of cystic fibrosis (CF) patients have led to a dramatic increase in the median life expectancy to 33 years, with children born today expected to reach their early 50 s [1, 2]. Liver disease is the third leading cause of CF-associated mortality, following pulmonary disease and transplant complications [1]. Autopsy studies have revealed a high prevalence of liver disease in CF patients, ranging from 10% in infants to 72% in adults [3, 4]. Multifocal biliary fibrosis and hepatic steatosis are the most common pathologic findings in CF liver disease, with secondary biliary cirrhosis, microgallbladder, cholecystitis, cholelithiasis, and sclerosing cholangitis also seen [5, 6].

Bioavailability and Disposition of Metoclopramide after Single‐ and Multiple‐Dose Administration in Diabetic Patients with Gastroparesis

The disposition of metoclopramide after acute and chronic administration was determined in four diabetic patients with gastroparesis who had a creatinine clearance of 70.8 ±10.7 mL/min (mean ± SD). Single, 10‐mg oral and intravenous doses were administered on days 1 and 2, respectively, followed by 10 mg orally every six hours for three weeks. A second, 10‐mg intravenous bolus dose was administered on the last morning of chronic therapy. Metoclopramide concentrations were determined by high performance liquid chromatography. The elimination half‐life, steady‐state volume of distribution, and total body clearance after the initial intravenous dose were 3.9 ± 1.2 hr, 2.7 ± 0.3 L/kg, and 0.57 ± 0.14 L/hr/kg, respectively. The initial bioavailability was 67.7 ± 12.6%. After three weeks of chronic therapy, no significant differences in total body clearance (0.72 ± 0.42 L/hr/kg) or bioavailability (77.5 ± 16.8%) were observed. Thus the pharmacokinetics and bioavailability of metoclopramide were not altered during chronic therapy in these diabetic patients.

Sclerosing Cholangitis Associated With Trichosporon Infection and Natural Killer Cell Deficiency In An 8-year-old Girl:

An 8-year-old previously healthy white girl presented with abdominal pain and vomiting of a month’s duration with recent weight loss and jaundice. She was the product of first-degree consanguinity. Family history was non-contributory. Physical examination revealed a thin, jaundiced child. A firm, non-tender liver edge was noted two centimeters below the right costal margin. Laboratory tests, summarized in Table 1, were consistent with a biliary disorder. Computerized abdominal tomography demonstrated multiple gallstones. Endoscopic retrograde cholangiopancreatography (ERCP) revealed multiple stenotic lesions in the distal biliary tree without evidence of ductal stones. Colonoscopy to the ileum was normal. A cholecystectomy was performed, during which a 1.5 cm stone and exudate were found in the cystic duct. A liver biopsy was also performed at that time. Pathologic examination of the gallbladder and cystic duct demonstrated granulomatous inflammation with eosinophilia as well as necrotic foci with giant cells and yeast-like forms in the lamina propria and serosa (Fig. 1). The liver histology was consistent with cholangitis. Gallbladder cultures grew Trichosporon beigelii (asahii). The patient was treated with a low fat diet, parenteral nutrition, ursodiol, and a two week course of intravenous amphoterocin B. Follow-up ERCP continued to demonstrate multiple, segmental irregularities of the main cystic and hepatic ducts (Fig. 2). A stent was placed to allow for biliary drainage. Her symptoms diminished, her laboratory values normalized, and she was discharged on itraconazole to be taken by mouth for one year. Further evaluation included an immunologic profile (Table 2). The patient was deficient in suppressor/cytotoxic T (CD8) cells and natural killer (NK) cells (CD16+CD56). Cytotoxic testing of NK cell lytic activity showed complete absence of NK cell function. A quantitative immunoglobulin (Ig) panel showed elevation of IgE. Lymphocyte and neutrophil function, leukocyte adhesion, and complement studies were all normal. Autoimmune antibody titer for anti-saccaromyces cerevisiae antibody, anti-neutrophilic cytoplasmic antibody, and anti-nuclear antibody were negative. Smooth-muscle antibody was minimally elevated with a titer of 40 (normal titer <20). Genetic testing was negative for chromosomal deletions, duplications, or translocations. Evaluations for human immunodeficiency virus, histoplasmosis, blastomycosis, leptospirosis, Epstein-Barr Virus, Hepatitis Virus A, B, and C, and tuberculosis were negative. In the year after diagnosis, she underwent multiple ERCPs, largely for stent blockage and maintenance. The irregularities of the pancreatic duct and biliary tree slowly improved. Biopsy and cytologic specimens were obtained and cultured at each subsequent ERCP. Specimens became negative for trichosporon four months after initial presentation. The bile duct irregularities gradually improved but were still apparent at the last ERCP. Eighteen months after initial presentation, the patient was free of symptoms. She was thriving and had normal serum tests of liver and biliary function. Received January 22, 2003; revised May 9, 2003; accepted May 16, 2003. Address correspondence and reprint requests to Dr. Doron D. Kahana, Department of Pediatrics, University of Minnesota, 13–130 Phillips Wangensteen Building, 516 Delaware Street S.E., Minneapolis, MN 55455 (e-mail: kahan005@umn.edu). Journal of Pediatric Gastroenterology and Nutrition 37:620–623

Pneumothorax: Complication of enteral feeding tube placement

To The Editor: Enteral alimentation is often recommended for nutritional support (1). Placement of a small bore (1-5 mm) polyurethane tube with a tungstenweighted end is believed to be a safe, simple procedure. A stylet stiffens the tube and contributes to the risk of perforation if malpositioned. Pneumothorax as a complication of feeding tube placement in patients with cuffed endotracheal tubes has been described in the pulmonary literature (2, 3). However, little information is available in the gastrointestinal literature. We often assist in the nutritional management of mechanically ventilated patients and report here four cases of malpositioned feeding tubes with resultant pneumothoraces (Table 1). Our patients developed pneumothoraces~while on mechanical ventilation because the feeding tube entered the pleural space. Each patient required a chest tube to evacuate the pneumothorax. Although no patient developed hemodynamic compromise, a pneumothorax while receiving positive pressure ventilation could become a tension pneumothorax with the attendant risk of cardiovascular collapse. An intact gag reflex usually prevents accidental passage of a tube into the trachea. Risk of malposition is increased if the gag reflex is impaired or if the patient is sedated or uncooperative. A newly recognized risk factor is the presence of a cuffed endotracheal tube. Most endotracheal tubes in use today have a high-volume-low-pressure cuff. Some cuffs do not prevent the entrance of pharyngeal secretions (4) or enteral feeding tubes (5). If the feeding tube does enter the trachea by passing the cuff, perforation of the bronchial wall and visceral pleura can occur with surprising ease and minimal resistance. There are accepted guidelines for ensuring proper nasogastric tube placement (6): (1) insufflation of air with sound heard over the abdominal left upper quadrant; (2) aspiration of fluid consistent with placement in the stomach; and (3) absence of coughing, suggesting proper placement in the esophagus. Such criteria are unreliable in these patients. Sounds with insufflation may be air bubbling in the pleural space. Aspirated fluid may be from the lung or pleural space (2). An impaired cough reflex or an endotracheal tube may prevent response to the tubes presence in the trachea. These complications carry significant morbidity and are iatrogenic. Several simple steps can be followed to avoid improper placement. 1. Enteral feeding tubes should be placed only by experienced personnel. Education regarding complications should be given. 2. if any resistance is met, no further attempts at blind passage should be made. However, a lack of resistance during insertion does not ensure proper placement. 3. Standard criteria to assure proper placement cannot be used. Radiographic confirmation is necessary before initiation of feeding. 4. Fluoroscopy can be used as the tubes are radiopaque (7). 5. Laryngoscopically or endoscopically directed placement can be utilized (2, 8). 6. Repeated attempts at blind passage are not warranted. If one or two attempts are unsuccessful, direct vision or fluoroscopy should be used to place the tube. Thus, the presence of a cuffed endotracheal tube does not ensure that the trachea is protected. Gastroenterologists need to be cognizant of this serious complication of enteral tube feeding placement. When instituting nutritional support in this group of