CO2 or air cholangiography reduces the risk of post-ERCP cholangitis in patients with Bismuth type IV hilar biliary obstruction.

BACKGROUND: Endoscopic biliary stenting by endoscopic retrograde cholangiopancreatography (ERCP) is the most common form of palliation for malignant hilar obstruction. However, ERCP in such cases is associated with a risk of cholangitis. The incidence of post-ERCP cholangitis is particularly high in Bismuth type IV hilar obstruction, and this risk is further increased when the contrast injected for cholangiography is not drained. The present study aims to compare the incidence of cholangitis associated with the use of a contrast agent, air and CO2 for cholangiography in type IV hilar biliary lesions. METHODS: The clinical data of consecutive 70 patients with type IV hilar obstruction, who underwent ERCP from October 2013 to November 2017, were retrospectively analyzed. These patients were divided into three groups based on the agent used for cholangiography: group A, contrast (n = 22); group B, air (n = 18); group C, CO2 (n = 30). These three methods of cholangiography were chronologically separated. Prior to the ERCP, MRCP was obtained from all patients to guide the endoscopic intervention. RESULTS: At baseline, there was no significant difference in terms of the patient's age, gender, symptoms and liver function tests among the three groups (P > 0.05). The complication rates were significantly higher in group A than in groups B and C (63.6% vs. 26.7 and 27.8%, P < 0.05). The incidence of post-ERCP cholangitis was significantly higher in group A (P < 0.05), while the incidence of post-ERCP pancreatitis and bleeding were similar in the three groups. After the ERCP, the mean hospital stay was shorter in groups B and C, when compared to group A (P < 0.05). However, there was no significant difference in the 30-day mortality rate among the three groups (P > 0.05). Furthermore, there was no significant difference between groups B and C in terms of primary end points. CONCLUSION: CO2 or air cholangiography during ERCP for type IV hilar obstruction is associated with reduced risk of post-ERCP cholangitis, when compared to conventional contrast agents.

Utility of minimal preparation computed tomography colonography in detecting colorectal cancer in elderly and frail patients.

BACKGROUND: Colorectal cancers result in substantial morbidity and mortality to the Australian society each year. The usual investigation for bowel malignancy is optical colonoscopy (OC), with computed tomography colonography (CTC) used as an alternative investigation. The catharsis and colon insufflation associated with these investigations pose a higher risk in the elderly and frail. Risks include perforation, serum electrolyte disturbance and anaesthesia/sedation risks. Minimal preparation computed tomography colonography (MPCTC) eliminates these risks. AIMS: To audit the accuracy of a MPCTC programme for the investigation of colonic masses in symptomatic elderly and frail patients. METHODS: This paper audits a 6-year period of MPCTC in an Australian tertiary referral hospital. A total of 145 patients underwent MPCTC during the study period. RESULTS: There were seven true positives, two false positives and two false negatives. Analysis of this population indicates a sensitivity of 0.78 (95% CI 0.51-1.05), specificity of 0.99 (95% CI 0.97-1.01), positive predictive value (PPV) of 0.78 (95% CI 0.51-1.05) and negative predictive value (NPV) of 0.99 (95% CI 0.97-1.01). These findings are concordant with other published studies. CONCLUSIONS: This audit confirms that minimal preparation CT colonography is a reasonable alternative to OC and CTC in detecting colorectal cancer in symptomatic elderly and frail patients, without the procedural risks inherent in more invasive investigations. For most patients, MPCTC ruled out significant colorectal carcinoma with a high NPV.

Intentional right atrial exit for microcatheter infusion of pericardial carbon dioxide or iodinated contrast to facilitate sub-xiphoid access.

OBJECTIVES: We test the safety of transatrial pericardial access using small catheters, infusion of carbon dioxide (CO2 ) or iodinated contrast to facilitate sub-xiphoid access, and catheter withdrawal under full anticoagulation. BACKGROUND: Sub-xiphoid pericardial access is required for electrophysiological and structural heart interventions. If present, an effusion protects the heart from needle injury by separating the myocardium from the pericardium. However, if the pericardium is 'dry' then there is a significant risk of right ventricle or coronary artery laceration caused by the heart beating against the needle tip. Intentional right atrial exit is an alternative pericardial access route, through which contrast media could be infused to separate pericardial layers. METHODS: Transatrial pericardial access was obtained in a total of 30 Yorkshire swine using 4Fr or 2.8Fr catheters. In 16 animals, transatrial catheters were withdrawn under anticoagulation and MRI was performed to monitor for pericardial hemorrhage. In 14 animals, iodinated contrast or CO2 was infused before sub-xiphoid access was obtained. RESULTS: Small effusions (mean 18.5 ml) were observed after 4Fr (1.3 mm outer-diameter) but not after 2.8Fr (0.9 mm outer-diameter) transatrial catheter withdrawal despite full anticoagulation (mean activated clotting time 383 sec), with no hemodynamic compromise. Pericardial CO2 resorbed spontaneously within 15 min. CONCLUSIONS: Intentional transatrial exit into the pericardium using small catheters is safe and permits infusion of CO2 or iodinated contrast to separate pericardial layers and facilitate sub-xiphoid access. This reduces the risk of right ventricular or coronary artery laceration. 2.8Fr transatrial catheter withdrawal does not cause any pericardial hemorrhage, even under full anticoagulation.

[Carbon dioxide angiography in EVAR: basic principles, indications and limitations]. / Die CO2-Angiografie bei EVAR-Prozeduren: Grundlagen, Indikationen und Grenzen.

Compared to open surgery, endovascular aneurysm repair has shown superior results in terms of morbidity and mortality. Therefore the 2011 published Practical Guidelines for Abdominal Aortic Aneurysm Repair (EVAR) demand an individual evaluation of every patient concerning an EVAR solution. To reduce the risk of contrast-associated complications such as severe allergic reactions hyperthyroidism or contrast-induced nephropathy with permanent loss of renal function, the use of carbon dioxide should be considered for every case. The imaging software solutions are part of the modern angiography technique and the imaging quality of CO2 angiography is equivalent or even better as compared to conventional angiography when the patient is appropriately prepared and positioned.

Complications of CT colonography: a review.

Since its inception, one of the main advantages of computed tomography colonography (CTC) over colonoscopy has been its assumed superior safety profile. However CTC is not without complication and adverse events are well described. Although the risks of insufflation, bowel preparation, contrast media and radiation dose are very small, they are not insignificant. This review discusses the potential hazards and complications associated with the technique, and discuss precautions, which may lessen the risk of occurrence.

Near-fatal air embolus during arthrography of the hip in a baby aged four months.

We describe a near-fatal event, probably due to air embolism, following an air arthrogram for developmental hip dysplasia in a baby aged four months. The sequence of events and the subsequent treatment are described. There is little information about this complication in the literature. The presumed mechanism and alternative methods for confirmation of placement of the needle are discussed. We no longer use air arthrography in children.

Suspected case of venous air embolism in an infant undergoing hip arthrogram.

An otherwise well ten-week-old girl underwent an air contrast hip arthrogram and application of a hip spica for a developmentally dislocated hip. The child displayed signs consistent with venous air embolism after injection of 5 ml of air into the hip joint. These signs included a decrease in arterial haemoglobin oxygen saturation as measured by pulse oximetry, decreased end-tidal carbon dioxide level and tachycardia. The signs initially resolved, but the patient deteriorated with injection of a further 5 ml of air. The patient responded to cessation of injection and resuscitative measures. The infant remained well postoperatively. The need for the use of air to confirm intra-articular placement of the needle prior to injection of contrast during a hip arthrogram is questioned.

Is carbon dioxide as an insufflation agent for double contrast barium enema still worthwhile after a same-day flexible sigmoidoscopy?

PURPOSE: The aim of the study was to evaluate the efficacy of a double-contrast barium enema (DCBE) with CO(2) as a distending gas after a screening flexible sigmoidoscopy for reducing abdominal distension after an examination. PATIENTS AND METHODS: A total of 165 DCBEs for patients with positive faecal occult blood tests were randomly allocated to a CO(2) group (n = 83) and a control group (n = 82) using air. Abdominal radiograph were taken before the DCBE, immediately following it, and 30 minutes later to determine residual bowel gas. The degree of abdominal discomfort was recorded using a scoring system. RESULTS: The patients in the CO(2) group had significantly smaller amounts of residual gas 30 minutes after the DCBE than did the control group, both in the colon (P < 0.02) and in the small intestine (P < 0.001). There was significantly less abdominal distension after the DCBE in the CO(2) group compared to the control group (P < 0.001). The abdominal discomfort score at 30 minutes after CO(2) correlated with the residual gas in the small intestine (r = 0.390,P = 0.003) but not in the colon (r = 0.155, P = 0.15). The quality of the images and the number of polyps detected did not differ between two groups. CONCLUSIONS: We concluded that using CO(2) when administering a DCBE after a screening sigmoidoscopy was useful for relieving abdominal discomfort following the examination; furthermore, it did not impair the diagnostic ability of the DCBE.

Pain after small bowel meal and pneumocolon: a randomized controlled trial of carbon dioxide versus air insufflation.

AIM: To determine whether the use of CO2 rather than air insufflation results in less pain and/or distension in patients undergoing small bowel meal (SBM) and pneumocolon (PC). MATERIALS AND METHODS: One hundred patients for SBM and PC were randomized to receive either air or carbon dioxide (CO2) as the insufflating gas. Both the patient and radiologist were blinded to the gas being used. Patients were given a questionnaire to complete the following day. The degree and duration of abdominal pain and swelling were scored on a visual analogue scale from 0 to 100. RESULTS: Seventy-nine patients replied. The mean pain score was 28.1 for patients receiving air and 20.35 for those receiving CO2 (P < 0.05). The duration of pain was 9.0 h in the air group and 6.0 h in the CO2 group (P < 0.05). The mean abdominal swelling score was 27.1 for patients receiving air and 17.1 for those receiving CO2 (P < 0.05). The duration of swelling was 8.8 h in the air groups and 7.3 h in the CO2 group (P = 0.16). CONCLUSION: In patients presenting for SBM and PC, the severity and duration of abdominal pain and distension are significantly reduced by the use of CO2 rather than air.

Perforation during gas reduction of intussusception.

Perforation during attempted gas-enema reduction of intussusception is more common than during a barium enema. In a review of 650 consecutive attempted gas enemas, perforation occurred in 7 infants (1.1%). Gross abdominal distension from the pneumoperitoneum may be rapid and cause splinting of the diaphragm, which leads to acute respiratory distress. This complication is readily recognised at the time of the gas enema, and may require immediate intervention by paracentesis using a 14-gauge needle. A review of 7 children with intussusception in whom perforation occurred revealed that all had radiologic evidence of bowel obstruction (air-fluid levels) prior to the enema, and the patients had had a relatively long history since the onset of symptoms. No perforation occurred during a delayed repeat enema reduction. Perforation during gas enema produces minimal peritoneal contamination. No pathological lesion at the lead point of the intussusception was identified in any of the children in whom perforation occurred.

The role of carbon dioxide and atmospheric air in double-contrast barium enema.

BACKGROUND: Patient discomfort 0-24 h after double-contrast barium enema (DCBE) was investigated in two ways. METHODS: In part 1, 139 patients, not previously informed, were contacted by telephone to assess symptom rates without bias. In part 2, designed as a prospective randomized double-blind trial, the effect of carbon dioxide (CO2) as an insufflating gas was compared with conventional atmospheric air (AA). RESULTS: Part 1: 10% experienced severe abdominal pain, and 18% severe abdominal distention. Part 2: Low discomfort rates were found for both severe pain (7% for AA vs. 2% for CO2) and severe distention (13% for AA vs. 8% for CO2); the differences were not significant. In both parts of the study, female patients with a history of abdominal discomfort of "colon irritable" type were significantly overrepresented in the severely symptomatic groups. Equal numbers of patients experiencing severe abdominal distention for the first time were found in both the AA and CO2 groups, ruling out AA as the sole cause of these symptoms. CONCLUSION: Abdominal post-DCBE discomfort seems to be less frequent than previously reported and is not effectively eliminated by CO2. We still find the use of AA in DCBEs justified.

Perforation during attempted intussusception reduction in children--a comparison of perforation with barium and air.

This paper compares the effects on patients of perforation with barium and with air during attempted intussusception reduction by reviewing the clinical, radiological, surgical and pathological findings and sequelae in seven children who received barium and seven who received air. In both groups perforation occurred in infants under 6 months of age (with one exception) with a long duration of symptoms. All patients with barium enema required resection of bowel whereas only four with air enema required resection. Anesthetic times were longer in those patients with barium perforation in whom the intussusception did not move and there was a large leak. The patients with perforation due to air had a shorter hospital stay with decreased morbidity compared to those with perforation due to barium. Perforation occurred through areas of transmural necrosis in a minority of patients in each group. Perforations through normal bowel and shear injury (with air enema) indicate that increased pressure during the examination is an important factor in some patients. Because perforation with air is so much easier to deal with surgically and the children do better clinically, there is a tendency for some to consider perforation with air an inconsequential situation. However, a potential rare complication with this technique is tension pneumoperitoneum. Keeping this in mind, we continue to use air as the contrast of choice because the procedure in our hands is a safe, quicker and easier technique and we have achieved a substantial improvement in reduction rates. Overall reported perforation rates with air enema compare favourably with those due to barium enema.(ABSTRACT TRUNCATED AT 250 WORDS)

Air intussusception reduction: "the winds of change".

AIR is an excellent example of the application of the scientific process to the treatment of pediatric disease. For more than 40 years, pediatric radiologists in North America were comfortable with hydrostatic enemas for the diagnosis and treatment of intussusception. Initial clinical trials in the 1980s suggested the efficacy of AIR. Subsequent clinical studies demonstrated that fluoroscopy time and radiation are less, accurate pressure measurements are possible, and reduction rates are higher with AIR than with hydrostatic techniques. Questions regarding safety and types of perforation were answered in the laboratory with an animal model. Moreover, this experimental work clarified issues regarding maximum pressures and the importance of the Valsalva maneuver during AIR. Experimental data has been transferred to the radiological treatment of childhood intussusception. The "winds of change", generated by clinical and basic research, have now swept across North America. More and more radiologists are performing AIR. Many of the pediatric radiologists who still doubt the efficacy of AIR have had no experience with the technique. Air insufflation is safe and effective for the diagnosis and treatment of intussusception in infants and children. It is replacing the hydrostatic enema in an ever-increasing number of institutions. AIR is quicker, safer, and more effective than hydrostatic enemas. If you are using AIR, I hope this overview will further improve the radiological care of your pediatric patients. If you are not using AIR, I hope that these personal observations will stimulate your interest. "Try it; you'll like it!"

The use of carbon dioxide as an insufflation agent in barium enema--does it have a role?

A double blind prospective study was undertaken to evaluate the benefit of using carbon dioxide in double contrast barium enema (DCBE). 142 consecutive patients referred for DCBE were randomly allocated to receive either air or carbon dioxide (CO2) as the insufflation agent. The use of CO2 reduced the incidence of immediate and delayed severe pain from 31% to 12.5% and from 12.9% to 4.2% respectively. There was a statistically significant higher incidence of delayed severe pain in the younger age group as found in previous studies. Post-evacuation films showed that there was less residual gas after CO2. The quality of the DCBE was unchanged. We urge the more widespread use of CO2 as insufflation agent in DCBE.