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Biomedical subjects

R C Wong

Publications and source records attributed to R C Wong.

At least 19 recordsLinked to original sources
PubMed2001

Effectiveness of endoscopy in patients admitted to the intensive care unit with upper GI hemorrhage.

BACKGROUND: Esophagogastroduodenoscopy (EGD) is generally indicated for the management of patients admitted to intensive care units (ICUs) with upper gastrointestinal (GI) hemorrhage but its impact in community practice has not been measured. Thus, the effectiveness of 3 EGD factors, viz., accurate initial diagnosis, performance within 24 hours of admission (early EGD), and appropriate intervention, was examined. METHODS: Records of 214 patients admitted to the ICU of 10 metropolitan hospitals with upper GI hemorrhage were reviewed. Unadjusted and severity-adjusted associations of the 3 EGD factors with length of hospital stay, length of ICU stay, readmission to ICU, recurrent bleeding, surgery, and death were evaluated. RESULTS: Inaccurate diagnosis occurred in 10% of patients at initial EGD and was associated with significant increases in risk of recurrent bleeding (70% vs. 11%, p < 0.001), rate of surgery (20% vs. 4%, p < 0.05), length of hospital stay (median 7.5 vs. 5 days, p < 0.005), length of ICU stay (median 4 vs. 2 days, p < 0.005), and rate of readmission to ICU (20% vs. 0.6%, p < 0.001). These associations persisted after adjusting for severity of illness. Early EGD performed in 82% of patients was associated with significant severity-adjusted reductions in hospital (-33%: 95% CI [-45%, -18%]) and ICU (-20%: 95% CI [-24%, -3%]) stay. Appropriate intervention at initial EGD, performed in 84% of patients, was associated with reductions in severity-adjusted length of ICU stay (-18%: 95% CI [-32%, 0%]) and rate of recurrent bleeding (odds ratio = 0.37, 95% CI [0.13, 1.06]). CONCLUSIONS: Early, accurate EGD with appropriate therapeutic intervention is effective as practiced in the community and is associated with improved outcomes for patients with upper GI hemorrhage admitted to the ICU. Inaccurate diagnosis at initial EGD is uncommon but has a significant adverse association with all outcome measures.

Endoscopy, Digestive System↗
PubMed2001

Wire-guided intraductal US: an adjunct to ERCP in the management of bile duct stones.

BACKGROUND: Endoscopic retrograde cholangiography (ERC) may misdiagnose bile duct stones if air bubbles are introduced during contrast injection, and it may also fail to diagnose stones in the presence of bile duct dilation. METHODS: Our aim was to determine whether intraductal US (IDUS) improves the accuracy of cholangiography and whether it is a useful adjunct in the management of bile duct stones. IDUS with a wire-guided US probe was performed after initial ERC in patients in whom bile duct stones were suspected. The diagnostic accuracy of ERC alone was compared with that of ERC plus IDUS. RESULTS: ERC with IDUS was performed in 62 patients who were suspected to have bile duct stones. Both IDUS and ERC were performed by the same endoscopist, and ERC was performed with a C-arm fluoroscope. The presence of bile duct stones and/or sludge were confirmed after sphincterotomy and extraction in 34 patients. Overall, the accuracy of ERC combined with IDUS in the diagnosis of bile duct stone and/or sludge was higher than that of ERC alone (97% vs. 87%, p < 0.05). With dilated bile ducts, the diagnostic accuracy of ERC combined with IDUS was also higher than that of ERC alone (95.5% vs. 72.7%, p < 0.05). Additional diagnostic information provided by IDUS included identification of cystic duct stones in 5 patients, characterization of bile duct strictures in 2 patients, and choledochal varices in 1 patient. Performance of wire-guided IDUS required 5% of the total procedure time. CONCLUSIONS: IDUS improves diagnostic accuracy of ERC and is a useful adjunct to ERC when bile duct stones are suspected.

Aged↗
PubMed2001

High-resolution endoscopic imaging of the GI tract: a comparative study of optical coherence tomography versus high-frequency catheter probe EUS.

BACKGROUND: Both optical coherence tomography (OCT) and catheter probe EUS (CPEUS) are candidates for high-resolution imaging of the GI wall, but their potential roles in this clinical context have not been investigated. METHODS: OCT and CPEUS were used to image normal-appearing portions of the GI tract at the same sites. CPEUS was performed with a 20-MHz or a new 30-MHz catheter probe. RESULTS: Forty-four histologically confirmed normal sites in 27 patients were evaluated. With OCT, mucosa and muscularis mucosa were clearly seen at all sites. Except for stomach, OCT demonstrated the submucosa in all sites. OCT penetration ranged from 0.7 to 0.9 mm. Microscopic structures such as esophageal glands, intestinal villi, colonic crypts, and blood vessels were easily identified. CPEUS penetration ranged from 10 mm to 20 mm, and 5 to 7 distinct layers were discernible. However, both mucosa and submucosa were seen as thin layers without microscopic detail. CONCLUSION: OCT resolution is superior to high-frequency CPEUS, but depth of penetration is limited to mucosa and submucosa. OCT images the major structural components of the mucosa and submucosa whereas CPEUS does not. Potentially, OCT and high-frequency CPEUS may be complementary for clinical imaging.

Endoscopy, Gastrointestinal↗
PubMed2000

Prospective evaluation of an over-the-wire catheter US probe.

BACKGROUND: Pancreaticobiliary strictures identified at endoscopic retrograde cholangiopancreatography (ERCP) can be evaluated by intraductal ultrasonography (US). Two major difficulties are that sphincterotomy may be required and the stricture may not be traversable. We prospectively evaluated the ease and success of intraductal US using a new over-the-wire catheter US probe. METHODS: Biliary or pancreatic strictures discovered at ERCP were imaged with the new probe. Intraductal US performance times, image clarity, imaging depth and technical ease were measured. RESULTS: Twenty-one patients with a variety of inflammatory and malignant pancreaticobiliary lesions were studied. Thirteen of the 16 (81%) masses imaged by intraductal US were 10 mm or less in diameter. Sphincterotomy was not required. All strictures traversed by a guidewire were imaged. The sphincter of Oddi was successfully imaged in all patients with intact normal sphincters. Performance of intraductal US was rated as technically easy in all cases and image clarity was rated as good or very good in 15 of 21 (71%) cases. CONCLUSIONS: The new over-the-wire catheter US probe facilitates intraductal US. Sphincterotomy is avoided and strictures are successfully traversed. This probe makes it possible to image the sphincter of Oddi.

Adult↗
PubMed2000

High-resolution endoscopic imaging of the GI tract using optical coherence tomography.

BACKGROUND: Optical coherence tomography (OCT) has demonstrated the microscopic structure of the gastrointestinal (GI) tract mucosa and submucosa in vitro. We evaluated a prototype OCT system and assessed the feasibility of OCT in the human GI tract. METHODS: The 2.4 mm diameter prototype OCT probe, inserted through an endoscope, provides a 360-degree radial scan. Images (6.7 frames/sec) are displayed on a television monitor. Tissue contact is not required. In patients undergoing elective endoscopy, OCT images were obtained of normal mucosa (confirmed by biopsy). RESULTS: Seventy-two sites were imaged (38 patients): esophagus (21), stomach (12), duodenum (11), terminal ileum (4), colon (15), and rectum (9). Varying the distance between the probe and the mucosal surface produced images of the GI wall of varying depth. When held about 1 mm above the mucosal surface, the images consisted of mucosal structures such as colonic crypts, gastric pits, and duodenal villi. With the probe held against the wall, the OCT image comprised several layers interpreted as mucosa, muscularis mucosae, and submucosa. Structures including blood vessels were evident within the submucosa. A probe with a 0.5 mm working distance to the focal point provided the best images. Reducing the frame rate to 4.0 per second facilitated image interpretation. CONCLUSIONS: OCT is feasible in the human GI tract and provides interpretable high-resolution images of mucosa and submucosa.

Adult↗
PubMed2000

Role of Doppler US in acute peptic ulcer hemorrhage: can it predict failure of endoscopic therapy?

BACKGROUND: Recurrent bleeding after successful primary endoscopic hemostasis of acutely bleeding ulcers is a significant problem. This study evaluates endoscopic Doppler ultrasound (US) in assessing risk of recurrent bleeding in patients presenting with acute peptic ulcer hemorrhage. METHODS: In this prospective, double-blind, nonrandomized trial, patients were enrolled from a single academic institution. Only patients with endoscopically confirmed gastric, duodenal, pyloric, or anastomotic ulcers were enrolled. The therapeutic endoscopist was blinded to the Doppler US signal from the ulcer and based treatment decisions on standard guidelines. A 16 MHz pulsed-wave, linear scanning, US probe was used through the accessory channel of an endoscope to assess for the presence of a Doppler signal. RESULTS: Fifty-two of 139 screened patients entered the trial (55 Doppler sessions). Endoscopic therapy was performed in 42% (30-day recurrent bleeding rate of 17%). Ulcers that remained persistently Doppler positive immediately after endoscopic therapy had a significantly higher rate of recurrent bleeding than ulcers where the Doppler signal was abolished: 100% versus 11% (p = 0.003). There were no bleeding-related deaths. CONCLUSIONS: A persistently positive Doppler US signal appears to be a marker of inadequate endoscopic therapy in patients with acutely bleeding peptic ulcers.

Acute Disease↗
PubMed2000

Pancreatic duct stents for "obstructive type" pain in pancreatic malignancy.

OBJECTIVE: Obstruction of the main pancreatic duct from malignancy with secondary ductal hypertension may be an important contributor to pain. The aim of our study was to determine the efficacy and safety of pancreatic stent placement for patients with "obstructive" pain due to pancreatic malignancy. METHODS: Pancreatic duct stents were placed in 10 consecutive patients with malignant pancreatic duct obstruction and abdominal pain. Seven patients had "obstructive" type pain and three had chronic unremitting pain. Nine had primary pancreatic ductal adenocarcinoma and one had metastatic melanoma. There were eight women and two men. Mean age was 61 yr (range, 47-80 yr). All patients had dominant main pancreatic duct strictures with proximal dilation. Tumors were unresectable. All patients took potent analgesics before endoscopic stent therapy. Polyethylene pancreatic stents, 5- and 7-French, were successfully placed in seven patients, and self-expanding metallic stents were successfully placed in three patients. RESULTS: There were no procedure-related complications. One patient required a single repeat examination to replace a migrated stent. Seven patients (75%) experienced a reduction in pain. Analgesia was no longer required in five (50%). Three patients who did not improve had chronic pain rather than "obstructive" pain. CONCLUSIONS: Pancreatic stent placement for patients with "obstructive" pain secondary to a malignant pancreatic duct stricture appears to be safe and effective. It should be considered as a therapeutic option in these patients. It does not seem to be effective for chronic unremitting pain.

Adenocarcinoma↗
PubMed2000

Design and implementation of an inpatient disease management program.

OBJECTIVE: To describe the development and implementation of an inpatient disease management program. STUDY DESIGN: Prospective observational study. PATIENTS AND METHODS: On the basis of opportunities for improving quality or efficiency of inpatient and emergency department care, 4 diagnoses, including congestive heart failure (CHF), gastrointestinal hemorrhage, community-acquired pneumonia and sickle-cell crisis were selected for implementation of a disease management program. For each diagnosis, a task force assembled a disease management team led by a "physician champion" and nurse care manager and identified opportunities for improvement through medical literature review and interviews with caregivers. A limited number of disease-specific guidelines and corresponding interventions were selected with consensus of the team and disseminated to caregivers. Physician and nurse team leaders were actively involved in patient care to facilitate adherence to guidelines. RESULTS: For quarter 2 to 4 of 1997, there were improvements in angiotensin-converting enzyme inhibitor use, daily weight compliance, assessment of left ventricular function, hospital costs, and length of stay for care-managed patients with CHF. Differences in utilization-related outcomes persisted even after adjustment for severity of illness. For the other 3 diagnoses, the observational period was shorter (quarter 4 only), and hence preliminary data showed similar hospital costs and length of stay for care-managed and noncare-managed patients. CONCLUSIONS: An interdisciplinary approach to inpatient disease management resulted in substantial improvements in both quality and efficiency of care for patients with CHF. Additional data are needed to determine the program's impact on outcomes of other targeted diagnoses.

Academic Medical Centers↗
PubMed1999

Use of open access in GI endoscopy at an academic medical center.

BACKGROUND: Open access endoscopy systems (those in which endoscopy is performed without prior gastroenterology consultation) are becoming more common in the current cost-conscious environment. The aim of this study was to compare appropriateness and yield of endoscopy for patients referred for open access endoscopy with those for patients who had prior contact with a gastroenterologist. We also evaluated patients' preference for undergoing open access endoscopy as opposed to having prior consultation with a gastroenterologist and compared preparedness for endoscopic procedures between the two groups. METHODS: The cases of all outpatients referred for upper endoscopy and colonoscopy were assessed prospectively over a 5-month period. American Society for Gastrointestinal Endoscopy (ASGE) guidelines for indications for gastrointestinal endoscopy were used to determine appropriateness of referrals. Significant pathologic findings were rated independently by two investigators using defined criteria. Patients' opinions regarding preparedness for endoscopy and referral preference were measured by means of questionnaires administered before endoscopy. RESULTS: Eighty-six percent of endoscopies after consultation with gastroenterologists were performed for accepted indications compared with 65% of open access procedures (p < 0.01). Significant pathologic findings were present in 40% of the former group compared with 28% of those undergoing open access endoscopy (p < 0.01). Significant pathologic findings were found in 37% of endoscopies performed for indications listed in the ASGE guidelines compared with 20% for unlisted indications (p < 0.01). Forty percent of patients referred for open access endoscopy would have preferred prior consultation with a gastroenterologist. CONCLUSION: Patients initially seen by a gastroenterologist are more likely to undergo endoscopy for accepted indications, and the yield of endoscopy is higher than among patients referred through an open access system. The system of open access endoscopy as currently practiced may have to be reassessed.

Academic Medical Centers↗
PubMed1999

Prospective assessment of the utility of EUS in the evaluation of gallstone pancreatitis.

BACKGROUND: The ability to identify common bile duct stones by noninvasive means in patients with acute biliary pancreatitis is limited. The aim of this study was to prospectively evaluate the ability of endosonography (EUS) to identify cholelithiasis and choledocholithiasis and predict disease severity in patients with nonalcoholic pancreatitis. METHODS: EUS was performed immediately before endoscopic retrograde cholangiopancreatography (ERCP) by separate blinded examiners within 72 hours of admission. Gallbladder findings were compared between EUS and transabdominal ultrasonography (US). Using endoscopic extraction of a bile duct stone as the reference standard for choledocholithiasis, the diagnostic yield of EUS was compared with transabdominal US and ERCP. Features identified during endosonographic imaging of the pancreas were correlated with length of hospitalization. RESULTS: Thirty-six patients were studied. EUS and transabdominal US were concordant in their interpretation of gallbladder findings in 92% of patients. The sensitivity of transabdominal US, EUS, and ERCP for identifying choledocholithiasis was 50%, 91%, and 92% and the accuracy was 83%, 97%, and 89%, respectively. Length of hospital stay was longer in patients with peripancreatic fluid (9.2 vs. 5.7 days, p < 0.1) and shorter in patients with coarse echo texture (2.6 vs. 7.2 days, p < 0.05) demonstrated on EUS. CONCLUSIONS: EUS can reliably identify cholelithiasis and is more sensitive than transabdominal US in detecting choledocholithiasis in patients with biliary pancreatitis. EUS may be used early in the management of patients with acute pancreatitis to select those who would benefit from endoscopic stone extraction. The utility of EUS for predicting pancreatitis severity requires further investigation.

Abdomen↗
PubMed1999

Toxic epidermal necrolysis in acquired immunodeficiency syndrome treated with intravenous gammaglobulin.

A 31-year-old man with the acquired immunodeficiency syndrome who developed toxic epidermal necrolysis (TEN) was successfully treated with intravenous immunoglobulin. He presented with a widespread, blistering skin rash, extensive mucosal ulceration, high-grade fever and pancytopaenia. Nevirapine, a non-nucleoside reverse transcriptase inhibitor, was suspected as the culprit drug, although the patient had been taking this medication for 6 months. The patient also demonstrated an increased number of gamma/delta (gamma delta) T cells that decreased concomitantly with his clinical improvement. This correlation has not been described in TEN previously and may be of pathophysiological significance.

Acquired Immunodeficiency Syndrome↗