Impact of ERCP simulator training on early ERCP learning curves of novice trainees: a cohort study

Background and study aim Simulator-based training has been extensively studied in training gastroduodenoscopy and colonoscopy and shown to significantly improve learning curves of novices. Data on simulator-based training in endoscopic retrograde cholangiopancreatography (ERCP) are scarce. We aimed to determine the impact of 2-day intensive hands-on simulator training on the course of the learning curve of novice trainees. Methods We conducted a prospective cohort study using a validated mechanical ERCP simulator (Boškoski-Costamagna ERCP Trainer). Six trainees were allocated to the simulation course program (SG). Each of these trainees were paired with an endoscopy trainee starting regular ERCP training at the same center who had no exposure to a simulation course program (control group; CG). The course included lectures, live ERCP demonstrations, and hands-on ERCP training to educate trainees in basic techniques related to cannulation, stent placement, stone extraction and stricture management. After the course, both the SG and CG started formal ERCP training in their respective centers. The Rotterdam Assessment Form for ERCP was used to register each performed ERCP. Simple moving average was applied to create learning curves based on successful common bile duct (CBD) cannulation. Outcomes were plotted against a historical cohort (HC). Results Thirteen trainees were included, six trainees in the SG and seven trainees in the CG, with a total of 717 ERCPs. Mean successful ERCP cannulation rate was higher for the simulator group at baseline compared to both CG and HC, 64% versus 43% and 42%, respectively. Differences became less explicit after 40 ERCPs, but persisted until a median of 75 ERCPs. Conclusions We demonstrate that 2-day hands-on simulator-based ERCP training course has a positive effect on the learning curves of ERCP trainees and should be considered an integral part of the training curricula for ERCP to develop skills prior to patient-based training.

Clinical practice patterns in indirect peroral cholangiopancreatoscopy: outcome of a European survey

Background and aims  Indirect peroral cholangiopancreatoscopy (IPOC) is a relatively new diagnostic and therapeutic tool for biliopancreatic diseases. This international survey aimed to evaluate clinical practice patterns in IPOC among endoscopists in Europe. Methods  An online survey was developed comprising 66 questions on the use of IPOC. Questions were grouped into four domains. The survey was sent to 369 endoscopists who perform IPOC. Results  86 respondents (23.3 %) from 21 different countries across Europe completed the survey. The main indications for cholangioscopy were determination of biliary strictures (85 [98.8 %]) and removal of common bile duct or intrahepatic duct stones (79 [91.9 %]), accounting for an estimated use of 40 % (interquartile range [IQR] 25-50) and 40 % (IQR 30-60), respectively, of all cases undergoing cholangioscopy. Pancreatoscopy was mainly used for removal of pancreatic duct stones (68/76 [89.5 %]), accounting for an estimated use of 76.5 % (IQR 50-95) of all cases undergoing pancreatoscopy. Only 13/85 respondents (15.3 %) had an institutional standardized protocol for targeted cholangioscopy-guided biopsy sampling. IPOC with lithotripsy was used as first-line treatment in selected patients with bile duct stones or pancreatic stones by 24/79 (30.4 %) and 53/68 (77.9 %) respondents, respectively. Conclusions  This first European survey on the clinical practice of IPOC demonstrated wide variation in experience, indications, and techniques. These results emphasize the need for prospective studies and development of an international consensus guideline to standardize the practice and quality of IPOC.

Safety and efficacy of digital single-operator pancreatoscopy for obstructing pancreatic ductal stones

Background and study aims The role of the digital single-operator pancreatoscopy (D-SOP) with electrohydraulic (EHL) or laser lithotripsy (LL) in treating pancreatic ductal stones is unclear. We investigated the safety and efficacy of D-SOP with EHL or LL in patients with obstructing pancreatic duct stones.

Patients and methods Retrospective analysis of 109 patients who underwent D-SOP for pancreatic stones at 17 tertiary centers in the United States and Europe from February 2015 to September 2017. Logistic regression was performed to identify factors associated with the need for more than one D-SOP with EHL/LL.

Results Most patients were males (70.6 %),mean age 54.7 years. Fifty-nine (54.1 %) underwent EHL and 50 (45.9 %) underwent LL. Mean procedure time was longer in the EHL group (74.4 min vs 53.8 min; P < 0.001). Ducts were completely cleared (technical success) in 89.9 % of patients (94.1 % in EHL vs 100 % in LL; P = 0.243), achieved in a single session in 73.5 % of patients (77.1 % by EHL and 70 % by LL; P= 0.5).D-SOP failed in 11 patients (10.1 %); 6 patients were treated with extracorporeal shockwave lithotripsy (ESWL), 1 with surgery,1 with combined treatment (ESWL + D-SOP EHL) and 3 with other. Fourteen adverse events occurred in 11 patients (10.1 %). Patients with more than three ductal stones were more likely to have technical failure compared to those with less than three stones (17 % vs. 4.8 %; P = 0.04). Having more than three stones was independently associated with the need for more than one D-SOC EHL/LL session (OR 2.94, 95 % CI 1.13 – 7.65).

Conclusion D-SOP with EHL or LL is effective and safe in patients with pancreatic ductal stones.

UK Consensus on Normal Tissue Dose Constraints for Stereotactic Radiotherapy

Six UK studies investigating stereotactic ablative radiotherapy (SABR) are currently open. Many of these involve the treatment of oligometastatic disease at different locations in the body. Members of all the trial management groups collaborated to generate a consensus document on appropriate organ at risk dose constraints. Values from existing but older reviews were updated using data from current studies. It is hoped that this unified approach will facilitate standardised implementation of SABR across the UK and will allow meaningful toxicity comparisons between SABR studies and internationally.

Validation of a dose warping algorithm using clinically realistic scenarios

Objective:

Dose warping following deformable image registration (DIR) has been proposed for interfractional dose accumulation. Robust evaluation workflows are vital to clinically implement such procedures. This study demonstrates such a workflow and quantifies the accuracy of a commercial DIR algorithm for this purpose under clinically realistic scenarios.

Methods:

12 head and neck (H&N) patient data sets were used for this retrospective study. For each case, four clinically relevant anatomical changes have been manually generated. Dose distributions were then calculated on each artificially deformed image and warped back to the original anatomy following DIR by a commercial algorithm. Spatial registration was evaluated by quantitative comparison of the original and warped structure sets, using conformity index and mean distance to conformity (MDC) metrics. Dosimetric evaluation was performed by quantitative comparison of the dose–volume histograms generated for the calculated and warped dose distributions, which should be identical for the ideal “perfect” registration of mass-conserving deformations.

Results:

Spatial registration of the artificially deformed image back to the planning CT was accurate (MDC range of 1–2 voxels or 1.2–2.4 mm). Dosimetric discrepancies introduced by the DIR were low (0.02 ± 0.03 Gy per fraction in clinically relevant dose metrics) with no statistically significant difference found (Wilcoxon test, 0.6 ≥ p ≥ 0.2).

Conclusion:

The reliability of CT-to-CT DIR-based dose warping and image registration was demonstrated for a commercial algorithm with H&N patient data.

Advances in knowledge:

This study demonstrates a workflow for validation of dose warping following DIR that could assist physicists and physicians in quantifying the uncertainties associated with dose accumulation in clinical scenarios.

Type 1 autoimmune pancreatitis and IgG4-related sclerosing cholangitis is associated with extrapancreatic organ failure, malignancy, and mortality in a prospective UK cohort

OBJECTIVES

Type I autoimmune pancreatitis (AIP) and IgG4-related sclerosing cholangitis (IgG4-related SC) are now recognized as components of a multisystem IgG4-related disease (IgG4-RD). We aimed to define the clinical course and long-term outcomes in patients with AIP/IgG4-SC recruited from two large UK tertiary referral centers.

METHODS

Data were collected from 115 patients identified between 2004 and 2013, and all were followed up prospectively from diagnosis for a median of 33 months (range 1-107), and evaluated for response to therapy, the development of multiorgan involvement, and malignancy. Comparisons were made with national UK statistics.

RESULTS

Although there was an initial response to steroids in 97%, relapse occurred in 50% of patients. IgG4-SC was an important predictor of relapse (P<0.01). Malignancy occurred in 11% shortly before or after the diagnosis of IgG4-RD, including three hepatopancreaticobiliary cancers. The risk of any cancer at diagnosis or during follow-up when compared with matched national statistics was increased (odds ratio=2.25, CI=1.12-3.94, P=0.02). Organ dysfunction occurred within the pancreas, liver, kidney, lung, and brain. Mortality occurred in 10% of patients during follow-up. The risk of death was increased compared with matched national statistics (odds ratio=2.07, CI=1.07-3.55, P=0.02).

CONCLUSIONS

Our findings suggest that AIP and IgG4-SC are associated with significant morbidity and mortality owing to extrapancreatic organ failure and malignancy. Detailed clinical evaluation for evidence of organ dysfunction and associated malignancy is required both at first presentation and during long-term follow-up.

Survey of stereotactic ablative body radiotherapy in the UK by the QA group on behalf of the UK SABR Consortium

OBJECTIVE

To ascertain the progress being made towards the implementation of stereotactic ablative body radiotherapy (SABR) treatment in the UK, to obtain details of current practice in centres with an active treatment programme and to assess the projected future provision.

METHODS

In August 2012, an online questionnaire was sent to all 65 UK radiotherapy institutions. The included questions covered the current number of patients being treated and the intended number of patients for each clinical site; immobilization and motion management methods; CT scanning protocols; target and organ-at-risk delineation; treatment planning; image-guidance and treatment protocols; and quality assurance methods.

RESULTS

48/65 (74%) institutions responded by the end of November 2012, with 15 indicating an active SABR programme. A further four centres indicated that a SABR protocol had been established but was not yet in clinical use. 14 of the 29 remaining responses stated an intention to develop a SABR programme in the next 2 years.

CONCLUSION

The survey responses confirm that SABR provision in the UK is increasing and that this should be expected to continue in the next 2 years. A projection of the future uptake would suggest that by the end of 2014, UK SABR provision will be broadly in line with international practice.

Stereotactic ablative radiotherapy in the UK: current status and developments

Stereotactic ablative radiotherapy (SABR) has developed from the principles and techniques used in the stereotactic radiosurgery treatment of brain metastases. Advances in computer technology, imaging, planning and treatment delivery and evidence from retrospective analysis of single- and multi-institutional early-phase studies have established SABR in the treatment of medically inoperable early lung cancer. Effective multidisciplinary team working is crucial to safe delivery of SABR. The variation in patient selection, radiotherapy planning and delivery techniques has led to a collective approach to SABR implementation across the UK. Centres developing the technique are represented in the UK SABR Consortium, which is supported by the relevant UK professional bodies and represents a platform to develop extracranial SABR across the UK. The uptake of SABR in the UK has been slowed by workforce issues, but at least 15 centres are currently delivering treatment with over 500 patients treated using UK SABR Consortium guidance. A mentoring program is being piloted helping new centres to develop their programs, and over 30 UK centres are expected to be offering SABR treatment by the end of 2014. The use of consistent guidance for patient selection, treatment planning and delivery in the UK gives the opportunity to collect and audit toxicity and outcome across the centres, contributing to the internationally reported SABR experience. Having established this service in the UK, the development of SABR through clinical research is a priority, and with input from the Radiotherapy Trials Quality Assurance Group, the UK is developing a national study program that includes participation in international trials.

Comparison of adaptive radiotherapy techniques for the treatment of bladder cancer

OBJECTIVE

Day-to-day anatomical variations complicate bladder cancer radiotherapy treatment. This work quantifies the impact on target coverage and irradiated normal tissue volume for different adaptive strategies.

METHODS

20 patients were retrospectively planned using different three-dimensional conformal radiotherapy treatment strategies for whole-bladder carcinoma: (i) "conventional" treatment used isotropic expansion of the clinical target volume (CTV) by 15 mm to the planning target volume (PTV) for daily treatment; (ii) "plan of the day" used daily volumetric on-treatment imaging [cone beam CT (CBCT)] to select from four available plans with varying superior PTV margins; (iii) "composite" strategies used on-treatment CBCTs from Fractions 1-3 to inform a composite CTV and adapted PTV (5- and 10-mm margins for composite 1 and composite 2, respectively) for subsequent treatment. Target coverage was evaluated from available CBCTs (the first three fractions then the minimum weekly thereafter), and the reduction in the irradiated volume (i.e. within the 95% isodose) was quantified.

RESULTS

Plan of the day improved target coverage (i.e. all of the bladder within the 95% isodose throughout the treatment) relative to conventional treatment (p=0.10), while no such benefit was observed with composite 2. Target coverage was reduced with composite 1 relative to conventional treatment. The mean irradiated volume was reduced by 17.2%, 35.0% and 14.6% relative to conventional treatment, for plan of the day, composite 1 and composite 2, respectively (p<0.01 in all cases). No parameters predictive of large changes in bladder volume later in the treatment were identified.

CONCLUSIONS

Adaptive techniques can maintain or improve target coverage while allowing for reduced irradiated volume and possibly reduced toxicity. The plan-of-the-day technique appeared to provide the optimal balance between target coverage and normal tissue sparing.

ADVANCES IN KNOWLEDGE

This study suggests that plan-of-the-day techniques will provide optimal outcomes for adaptive bladder radiotherapy.

Endoscopic retrograde pancreatography criteria to diagnose autoimmune pancreatitis: an international multicentre study

BACKGROUND

Characteristic pancreatic duct changes on endoscopic retrograde pancreatography (ERP) have been described in autoimmune pancreatitis (AIP). The performance characteristics of ERP to diagnose AIP were determined.

METHODS

The study was done in two phases. In phase I, 21 physicians from four centres in Asia, Europe and the USA, unaware of the clinical data or diagnoses, reviewed 40 preselected ERPs of patients with AIP (n=20), chronic pancreatitis (n=10) and pancreatic cancer (n=10). Physicians noted the presence or absence of key pancreatographic features and ranked the diagnostic possibilities. For phase II, a teaching module was created based on features found most useful in the diagnosis of AIP by the four best performing physicians in phase I. After a washout period of 3 months, all physicians reviewed the teaching module and reanalysed the same set of ERPs, unaware of their performance in phase I.

RESULTS

In phase I the sensitivity, specificity and interobserver agreement of ERP alone to diagnose AIP were 44, 92 and 0.23, respectively. The four key features of AIP identified in phase I were (i) long (>1/3 the length of the pancreatic duct) stricture; (ii) lack of upstream dilatation from the stricture (<5 mm); (iii) multiple strictures; and (iv) side branches arising from a strictured segment. In phase II the sensitivity (71%) of ERP significantly improved (p<0.05) without a significant decline in specificity (83%) (p>0.05); the interobserver agreement was fair (0.40).

CONCLUSIONS

The ability to diagnose AIP based on ERP features alone is limited but can be improved with knowledge of some key features.

Kinetics of acute hepatitis B virus infection in humans

Using patient data from a unique single source outbreak of hepatitis B virus (HBV) infection, we have characterized the kinetics of acute HBV infection by monitoring viral turnover in the serum during the late incubation and clinical phases of the disease in humans. HBV replicates rapidly with minimally estimated doubling times ranging between 2.2 and 5.8 d (mean 3.7 +/- 1.5 d). After a peak viral load in serum of nearly 10(10) HBV DNA copies/ml is attained, clearance of HBV DNA follows a two or three phase decay pattern with an initial rapid decline characterized by mean half-life (t(1/2)) of 3.7 +/- 1.2 d, similar to the t(1/2) observed in the noncytolytic clearance of covalently closed circular DNA for other hepadnaviruses. The final phase of virion clearance occurs at a variable rate (t(1/2) of 4.8 to 284 d) and may relate to the rate of loss of infected hepatocytes. Free virus has a mean t(1/2) of at most 1.2 +/- 0.6 d. We estimate a peak HBV production rate of at least 10(13) virions/day and a maximum production rate of an infected hepatocyte of 200-1,000 virions/day, on average. At this peak rate of virion production we estimate that every possible single and most double mutations would be created each day.

T cell receptor usage of virus-specific CD8 cells and recognition of viral mutations during acute and persistent hepatitis B virus infection

T cells specific for a single viral epitope, but using different T cell receptors, should have flexibility in their epitope recognition to protect the infected host against the emergence of viral escape mutants. Therefore, polyclonality of the hepatitis B virus (HBV)-specific cytotoxic T lymphocyte response has been hypothesized to be a major determinant in the control of infection. We analyzed the Vbeta chain composition of the core 18-27-specific CD8 cells in acute and persistently HBV-infected patients using HLA-A2 tetrameric complexes and a panel of Vbeta antibodies. Different T cell receptors were utilized by core 18-27-specific CD8 cells both in patients with acute and chronic infection. The functional ability of these epitope-specific T cells to respond to potential viral mutations was then tested. The polyclonal HBV-specific CD8 response present in patients with acute hepatitis displayed a limited efficiency to recognize mutations introduced within the epitope. The ability of core 18-27-specific CD8 to tolerate epitope mutations was found only during persistent HBV infection. The data suggest that although a clonally heterogeneous CD8 response can be largely inhibited by the occurrence of single epitope mutations in primary HBV infection, preferential selection of T cells able to counteract the emergence of viral mutations can occur during persistent infection.

T cell receptor usage of virus-specific CD8 cells and recognition of viral mutations during acute and persistent hepatitis B virus infection

T cells specific for a single viral epitope, but using different T cell receptors, should have flexibility in their epitope recognition to protect the infected host against the emergence of viral escape mutants. Therefore, polyclonality of the hepatitis B virus (HBV)-specific cytotoxic T lymphocyte response has been hypothesized to be a major determinant in the control of infection. We analyzed the Vbeta chain composition of the core 18-27-specific CD8 cells in acute and persistently HBV-infected patients using HLA-A2 tetrameric complexes and a panel of Vbeta antibodies. Different T cell receptors were utilized by core 18-27-specific CD8 cells both in patients with acute and chronic infection. The functional ability of these epitope-specific T cells to respond to potential viral mutations was then tested. The polyclonal HBV-specific CD8 response present in patients with acute hepatitis displayed a limited efficiency to recognize mutations introduced within the epitope. The ability of core 18-27-specific CD8 to tolerate epitope mutations was found only during persistent HBV infection. The data suggest that although a clonally heterogeneous CD8 response can be largely inhibited by the occurrence of single epitope mutations in primary HBV infection, preferential selection of T cells able to counteract the emergence of viral mutations can occur during persistent infection.

Incubation phase of acute hepatitis B in man: dynamic of cellular immune mechanisms

After hepatitis B virus (HBV) infection, liver injury and viral control have been thought to result from lysis of infected hepatocytes by virus-specific cytotoxic T cells. Patients are usually studied only after developing significant liver injury, and so the viral and immune events during the incubation phase of disease have not been defined. During a single-source outbreak of HBV infection, we identified patients before the onset of symptomatic hepatitis. The dynamics of HBV replication, liver injury, and HBV-specific CD8+ and CD4+ cell responses were investigated from incubation to recovery. Although a rise in alanine transaminase (ALT) levels was present at the time of the initial fall in HBV-DNA levels, maximal reduction in virus level occurred before significant liver injury. Direct ex vivo quantification of HBV-specific CD4+ and CD8+ cells, by using human leukocyte antigen (HLA) class I tetramers and intracellular cytokine staining, showed that adaptive immune mechanisms are present during the incubation phase, at least 4 weeks before symptoms. The results suggest that the pattern of reduction in HBV replication is not directly proportional to tissue injury during acute hepatitis B in humans. Furthermore, because virus-specific immune responses and significant reductions in viral replication are seen during the incubation phase, it is likely that the immune events central to viral control occur before symptomatic disease.

Molecular epidemiology of a large outbreak of hepatitis B linked to autohaemotherapy

BACKGROUND

Unregulated skin-piercing procedures potentially facilitate the transmission of bloodborne pathogens. In February, 1998, a patient who had recently received autohaemotherapy at an alternative medicine clinic in the UK was diagnosed with acute hepatitis B. The autohaemotherapy procedure involved the drawing of 1 mL of the patient's blood, mixing with saline, and reinjection of the autologous blood mixture. We investigated the extent of hepatitis B virus (HBV) infection in patients and staff of the clinic.

METHODS

Patients who had attended the clinic between January, 1997, and February, 1998, were tested for serological markers of HBV, and for HBV DNA by PCR. HBV DNA was sequenced to assess the relatedness of the virus identified in the cases. We analysed the number and dates of visits with regard to HBV status.

FINDINGS

Serum samples were received from 352 patients and four staff members. Serological evidence of exposure to HBV was found in 57 (16%). Of the 33 patients and staff who were positive for hepatitis B surface antigen, 30 (91%) showed complete nucleotide identity in the DNA segments derived from the surface and core genes. Five patients with linked infection had markers of chronic hepatitis B, and one of these was regarded as the likely source of the outbreak. The attack rate was associated with the number of visits (p<0.0001) and the week of visit (p=0.011). Contaminated saline in a repeatedly used bottle was the probable vehicle of transmission.

INTERPRETATION

We have described a large community-based outbreak of hepatitis B due to transmission by a single HBV variant. Our findings emphasise the continuing risk of transmission of bloodborne viruses in all health-care settings where skin-piercing procedures are used.

Direct ex vivo analysis of hepatitis B virus-specific CD8(+) T cells associated with the control of infection

BACKGROUND & AIMS

Cytotoxic T cells have been suggested to be responsible for lysis of hepatitis B virus (HBV)-infected hepatocytes and control of virus infection. The frequency, kinetics, phenotype, and capacity for clonal expansion of circulating HBV-specific CD8 cells were analyzed directly in patients with acute HBV infection to clarify their pathogenetic role.

METHODS

Three HLA-A2 peptide tetramers able to visualize HBV core, envelope, and polymerase epitope-specific cytotoxic T lymphocytes were synthesized and used for flow cytometric analysis of antigen-specific populations.

RESULTS

Tetramer-positive cells specific for the core 18-27 epitope were found at a higher frequency than those specific for polymerase 575-583 and envelope 335-343 epitopes in most patients with acute HBV. The number of HBV-specific CD8 cells was highest during the clinically acute stage of infection and decreased after recovery. These cells expressed an activated phenotype and had an impaired capacity to expand in vitro and to display cytolytic activity in response to peptide stimulation. Recovery of these functions was observed when the frequency of specific CD8 cells decreased, coincident with a progressive decrease in their expression of activation markers.

CONCLUSIONS

This study provides the first ex vivo evidence that the highest frequency of circulating HBV-specific CD8 cells coincides with the clinically acute phase of hepatitis B. These cells exhibit an activated phenotype with limited further proliferative capacity that is restored during recovery.

Infection and hemostasis in decompensated cirrhosis: a prospective study using thrombelastography

Bacterial infections are common complications in decompensated cirrhosis, but their relationship with hemostasis has not been studied. We prospectively assessed whether infection affects hemostasis in cirrhosis using routine hemostasis tests and thrombelastography (TEG), a global test of hemostatic function. Eighty-four cirrhotic patients (Child-Pugh B: 26; C: 58) without overt bleeding or blood-product transfusion were prospectively evaluated with routine hemostasis tests and TEG on admission and/or the first day with signs of infection and 5 days later. There were 30 patients with infection; 15 had infection on admission, and 15 developed infection in hospital. In the patients who developed infection in hospital, there was a significant deterioration in all routine hemostasis tests except platelet count (PLT) and in all TEG parameters, on the first day of infection compared with 7 +/- 3 days previously. The same parameters significantly improved from the first day of infection to day 5 and after (P <.02) only in the 22 patients whose infection resolved, while the r, k, and alpha TEG parameters significantly worsened in the 8 patients with persistent infection. In those who developed infection in hospital and were cured (n = 11), the 5-day parameters did not differ from their preinfection values. In conclusion, bacterial infections frequently impair hemostasis in decompensated cirrhotic patients. Successful treatment of infection usually restores hemostasis parameters to preinfection levels in 5 days. Thus, infection may have a role in the bleeding diathesis of cirrhosis.

Drinking before endoscopy: milk or water?

BACKGROUND

The traditional fluid fast prior to endoscopy is unnecessary. We have previously shown that drinking water prior to endoscopy does not affect either the quality of mucosal views or residual gastric fluid volumes when compared to patients undergoing endoscopy after a standard fast. The present study was designed to establish whether milk, which may delay gastric emptying, could also be drunk prior to endoscopy without adverse effect.

METHODS

Forty-eight patients (mean age 48 years, range 20 to 79) undergoing routine upper gastrointestinal endoscopy after overnight fast were randomized to drink 200 ml of either still mineral water or full fat milk. Endoscopy was performed 90 minutes later, when all residual gastric fluid was aspirated via the endoscope. Volume and pH of gastric aspirate were measured and the quality of the mucosal view at endoscopy recorded as poor, adequate, or excellent.

RESULTS

No difference was shown between water (n = 27) and milk (n = 21) drinkers in residual gastric volume (mean +/- SEM, water vs milk) (16.0 ml +/- 1.5 vs 18.9 ml +/- 2.9) or pH (2.23 +/- 0.14 vs 2.48 +/- 0.14). Of those patients with poor, adequate, or excellent views, 4 of 4, 11 of 12, and 6 of 32 patients, respectively, were milk drinkers (chi-squared test for trend = 21.7, df = 1, p < 0.001), indicating significantly worse mucosal views in the group drinking milk.

CONCLUSION

Drinking water up to 90 minutes prior to endoscopy is safe, but milk should be discouraged because of suboptimal mucosal views.

Assessment of residual gastric volume and thirst in patients who drink before gastroscopy

BACKGROUND

Before endoscopy patients undergo an uncomfortable fluid fast to reduce the risk of gastric acid aspiration and to ensure good endoscopic views are obtained. However, fluids rapidly leave the stomach and thus a long fluid fast before endoscopy may not be required.

AIMS

The object of this study was to establish whether drinking before endoscopy is safe and relieves patients' symptoms of thirst.

PATIENTS AND METHODS

88 patients with American Society of Anaesthesiologists classification of physical status grades I and II were recruited in a controlled randomised single blind trial. The volume and pH of gastric aspirate obtained at gastroscopy was assessed in patients who drank 330 ml of water a minimum 90 minutes before their endoscopy and compared with values in patients who starved overnight.

RESULTS

44 patients who drank ('drinkers') 330 ml of water a mean 117 minutes before their morning gastroscopy had a similar volume and pH of gastric aspirate compared with 44 patients starved overnight ('starvers'); median volume 12.5 ml versus 10 ml, median pH 2.0 versus 2.0; 'drinkers' versus 'starvers' (NS). Before endoscopy patients were asked to score their thirst and hunger ratings as either none, mild, moderate or severe. Ratings for moderate and severe thirst were grouped together for analysis. The percentage of drinkers compared with starvers in each group with no thirst, mild thirst, and moderate severe thirst was 63%, 46%, and 37% respectively (chi 2 test for trend p < 0.05). Hunger ratings were similar in the two groups.

CONCLUSIONS

It is safe for elective day cases to drink a significant volume of water two hours before endoscopy and this alleviates symptoms of thirst.

Streptozotocin-induced diabetes in rats causes neuronal deficits in tyrosine hydroxylase and 5-hydroxytryptamine specific to mesenteric perivascular sympathetic nerves and without loss of nerve fibers

The aim of this study was to investigate the possibility that inadequate venous return to the heart in diabetes is the result of a neuropathy which affects autonomic nerves supplying the splanchnic vasculature. Mesenteric veins from rats with streptozotocin-induced diabetes were markedly dilated in vivo compared to veins from control animals. Dilation appeared to be the result of loss of muscle tone rather than hypertrophy or hyperplasia of the vessel wall. Using quantification by image analysis and double-labeling immunohistochemistry on mesenteric veins, significant reductions in the density of nerve plexuses staining for 5-hydroxytryptamine (5-HT) and tyrosine hydroxylase (TH) were shown in vessels from diabetic rats compared to controls. No reductions were observed in the density of nerve plexuses stained for the neuronal marker, PGP 9.5, or for substance P (SP), a marker for afferent nerve fibers. These results indicate neurochemical deficits in experimentally induced diabetes which are specific to perivascular noradrenergic nerves and which, within the time-scale of our experiments, do not involve loss of nerve fibers. These deficits may contribute to an increase in venous pooling of blood in the splanchnic vasculature of diabetic rats and thus to inadequate venous return to the heart.