A procedure-specific systematic review and consensus recommendations for postoperative analgesia following laparoscopic cholecystectomy.

BACKGROUND: Laparoscopic cholecystectomy has advantages over the open procedure for postoperative pain. However, a systematic review of postoperative pain management in this procedure has not been conducted. METHODS: A systematic review was conducted according to the guidelines of the Cochrane Collaboration. Randomized studies examining the effect of medical or surgical interventions on linear pain scores in patients undergoing laparoscopic cholecystectomy were included. Qualitative and quantitative analyses were performed. Recommendations for patient care were derived from review of these data, evidence from other relevant procedures, and clinical practice observations collated by the Delphi method among the authors. RESULTS: Sixty-nine randomized trials were included and 77 reports were excluded. Recommendations are provided for preoperative analgesia, anesthetic and operative techniques, and intraoperative and postoperative analgesia. CONCLUSIONS: A step-up approach to the management of postoperative pain following laparoscopic cholecystectomy is recommended. This approach has been designed to provide adequate analgesia while minimizing exposure to adverse events.

The classification of oesophageal 24 h pH measurements using a Kohonen self-organizing feature map.

Analysis of 24 h oesophageal pH studies can be problematic with many patients asymptomatic during the investigation, despite observations of reflux. The aim of this study was to carry out a cluster analysis of ambulatory pH studies to determine any underlying patterns and classes within the data. The results of 900 24 h pH studies were investigated using the Kohonen self-organizing feature map (SOFM), a neural network that can be used to identify clusters within multidimensional data. The clinical features were presented to the network and the main classes identified. The SOFM-based analysis showed that patients clinically assessed as having symptomatic reflux during the study could be described by four major classifications. The results also showed that the probability of identifying a correlation between symptoms and reflux during an investigation varies from 0.49 to 0.78 for the classes identified. The developed network may be a useful tool in the classification of pH data. The cluster-based technique may offer an alternative to standard statistical techniques for high-dimensional gastrointestinal data and form the basis of an expert system for the automated analysis of pH data.

Navigating and visualizing three-dimensional data sets.

This paper provides an overview of the main techniques being used for three-dimensional (3D) visualization of medical data sets and highlights some of the clinical benefits that can be obtained. One of the major advantages of using a 3D representation is that all of the slice data produced by the latest multislice CT and high gradient MR scanners can be utilized, and then presented to the clinician in an intuitive format. Continued advances in technology mean that high resolution 3D representations of patient specific anatomy can now be routinely obtained and so provide valuable input to diagnosis, planning and navigation tasks. Examples from these areas are presented and illustrated below. Future developments and possibilities are also discussed.

A pH-mucosa area unit of measure to consider morphology of the oesophagus when evaluating oesophagitis.

Gastro-oesophageal pH measurements are routinely carried out to quantify and determine if levels of acid reflux are responsible for symptoms. Although considered the 'gold standard', evidence suggests that pH measurements do not correlate well with the degree of oesophagitis seen during endoscopy. In this study the current measure of pH was critically examined taking into account both the effects of changes in luminal diameter and endoscopy observations. The oesophageal lumen diameter was investigated using a barium swallow for 25 patients presenting with oesophageal disorders. For each subject the widest luminal diameter was measured for a series of five controlled swallows. The results showed that the lumen diameter varied widely from 0.9 to 3.8 cm. An alternative approach to the current measurement of pH was explored. In this approach the exposure not only included the luminal pH and time exposed but also the area of mucosa exposed as a result of differing luminal diameters. Although it is currently not possible to assess the diameter or morphology of the oesophageal lumen during a pH study, the analysis highlighted that the current measure of pH exposure time does not include the area of mucosa exposed. These results may explain, to some extent, the poor correlation between pH measurements and degree of oesophagitis seen during endoscopy.

Intravenous n-acetylcysteine, ascorbic acid and selenium-based anti-oxidant therapy in severe acute pancreatitis.

BACKGROUND: To observe outcome in a cohort of patients with severe acute pancreatitis receiving multiple anti-oxidant therapy. METHODS: An observational study was carried out in 46 consecutive patients with acute pancreatitis fulfilling current Atlanta consensus criteria for severe disease. All patients received multiple anti-oxidant therapy based on intravenous selenium, N-acetylcysteine and ascorbic acid plus beta-carotene and alpha-tocopherol delivered via nasogastric tube. Principal outcomes were the effect of anti-oxidant supplementation on anti-oxidant levels, morbidity and mortality in patients on anti-oxidant therapy, case-control analysis of observed survival compared to predicted survival derived from logistic organ dysfunction score (LODS), logistic regression analysis of factors influencing outcome and side effect profile of anti-oxidant therapy. RESULTS: Paired baseline and post-supplementation data were available for 25 patients and revealed that anti-oxidant supplementation restored vitamin C (P = 0.003) and selenium (P = 0.028) toward normal. In univariate survival analysis, patient survival to discharge was best predicted by admission APACHE-II score with relative risk of death increasing 12.6% for each unit increase (95% CI 6.0% to 19.6%). The mean LODS calculated on admission to hospital was 3.7 (standard error of the mean 4.1) giving a predicted mortality for the cohort of 21%. The observed in-hospital mortality was 43%. CONCLUSIONS: Case-control analyses do not appear to demonstrate any benefit from the multiple anti-oxidant combination of selenium, N-acetylcysteine and ascorbic acid in severe acute pancreatitis.

Effects of a moderate dose of alcohol on simulated laparoscopic surgical performance.

BACKGROUND: In medicine, there is no professional regulation of the drinking of alcohol, nor a body of experimental evidence on which such regulation might be based. Here we report the acute and longer-term ("hangover") effects of a moderate dose of alcohol on performance, as assessed objectively on a laparoscopic surgical simulator. METHODS: In a single-blind, experimental study, medical student subjects were assigned randomly to an alcohol (1.05 mg/kg) or a placebo condition (n = 14 in each). The effects of alcohol on performance on the MIST Virtual Reality surgical simulator were examined 60-90 min and 600-630 min (after a night's sleep) following its ingestion. Measures of the number of errors, time taken, hand movement economy, and excessive use of diathermy were recorded. RESULTS: On each measure, performance was significantly impaired 60-90 min following alcohol ingestion, but there was no hangover effect 600-630 min later, following a night's sleep. This impairment could not be attributed to between-group differences in either predrink performance, expertise or estimated sleep duration during the night preceding the experimental session. CONCLUSIONS: Simulated surgical performance is impaired severely when estimated blood alcohol concentration (BAC) is just above the UK legal limit for driving. These results contribute new, objective and quantitative evidence to the current debate about the use and misuse of alcohol within the medical profession.

An investigation into the spatial relationship between complexity and motility within the oesophagus.

Nonlinear analysis techniques have recently been used in the characterization of complex physiological signals seen in pathological disorders such as epilepsy and cardiac fibrillation. In this study a series of controlled swallows from an asymptomatic demonstration group was investigated using oesophageal manometry. The nonlinear measure of complexity, largest Lyapunov exponents and phase portraits were then used to explore the complexity of motility patterns at different points within the oesophagus. Results indicate greater complexity within the region of the striated muscle in the upper oesophagus than that observed within the region of smooth muscle in the lower oesophagus. Phase portraits showed that manometry patterns within the asymptomatic demonstration group could be quite different, highlighting the problems in clinical diagnosis. The characterization of motility disorders associated with complex manometry patterns such as diffuse oesophageal spasm (DOS) and nonspecific motility disorder (NOMD) still represents a diagnostic challenge. The use of nonlinear techniques enabling the quantitative and qualitative measurement of oesophageal complexity is considered in the classification of such disorders.

Technical report: The introduction of a new synchronized oesophageal manometry and digital video-fluoroscopy (fluoromanometry) system into the radiology suite.

Following the development of a new fluoromanometry system enabling synchronous oesophageal manometry and barium swallow video-fluoroscopy, both the equipment and examination method have been successfully introduced into the radiology suite. The application of the system which uses a PC with video capture and a portable manometry recorder is described together with details of its implementation and the examination technique used.

Natural history of adhesional small bowel obstruction: counting the cost.

BACKGROUND: The aim of this study was to identify patients admitted with adhesional obstruction to determine if there was an identifiable pattern to the type of initial operation, the type of treatment used for the obstructive episode and the subsequent need for further treatment. METHODS: Patients with adhesional obstruction were identified retrospectively in a cross-sectional study using ICD codes relating to admissions in the years 1990 to 1996. The case notes were used to assess their outcome. RESULTS: Fifty-nine case notes from a total of 175 identified initially satisfied the inclusion criteria. These patients had a mean age at presentation of 51 (range 16-88) years and had undergone a total of 122 operations. Thirty-one patients (53 per cent) had a single previous operation with a median time to presentation with obstruction of 5.5 years (range 11 days to 34.7 years); 33 patients (56 per cent) were treated conservatively on their first admission. There was no statistically significant difference in the outcome in patients who received either conservative or surgical treatment. The length of stay in patients treated surgically (median 11 (range 2-47) days) was significantly longer than that for those treated conservatively (median 6 (range 1-39) days) (P< 0.001). A flow chart was constructed demonstrating the eventual outcome of the patients in the study, enabling the cost of adhesional obstruction to be calculated. CONCLUSION: This type of approach could be used to assess the potential effect of different treatment strategies for adhesional obstruction.

Progress with cholecystectomy: improving results in England and Wales.

BACKGROUND: The Comparative Audit Service of the Royal College of Surgeons of England studied laparoscopic cholecystectomy in England and Wales during 1990-1991. The follow-on study undertaken during 1994 provides data to assess progress. METHODS: Pro formas were sent to consultant surgeons, requesting data on open and laparoscopic cholecystectomies performed in their units during 1994 with data on mean stay, mortality, complications, and the use of peroperative cholangiography and bile duct exploration. The identity of the consultants was treated confidentially. RESULTS: Data were provided by 110 surgeons on 4823 cholecystectomies (1019 open and 3804 laparoscopic) and outcome was compared with that of 3319 attempted laparoscopic and 8035 open cholecystectomies carried out during 1990-1991. The proportion of cases attempted laparoscopically rose from 27.2 per cent in 1990-1991 to 78.9 per cent in 1994, and conversion to open cholecystectomy rose from 5.3 to 6.7 per cent respectively. During 1994 peroperative cholangiography was undertaken in 22.9 per cent of laparoscopic and 44.6 per cent of open cases. Complication rates were similar in the two study periods, except the number of reported haemorrhagic complications was reduced by 40 per cent and bile duct injuries by fivefold (from 0.33 to 0.07 per cent). CONCLUSION: During 1994 the audit sampled approximately 10 per cent of all cholecystectomies performed in England and Wales. The results suggest progress in surgical techniques compared with findings in 1990-1991.

Synchronous recording and review of oesophageal manometry and video fluoroscopy using a portable manometry recorder and PC with integrated digital video acquisition.

We present the technical details of a new system for the synchronous recording and review of a combined oesophageal manometry and video fluoroscopic barium swallow examination. The system developed uses a portable manometry recorder and personal computer (PC) with an integrated digital video acquisition system. These are controlled using software to enable the real time capture of digital video and manometric data throughout the combined examination. The recorded pressure waveforms can then be synchronously displayed on a screen with the recorded digital video of the fluoroscopic barium swallow. This new tool enables both comparative measurement and detailed analysis of the relationship between visualized bolus transport and pressure measurements. It provides for a deeper understanding and improved clinical assessment of complex motility disorders over those obtained when these two modalities are applied separately. The system is easily incorporated into a clinical radiology suite and it is both user and patient friendly. It uses readily available computer hardware together with multimedia software and is a comparatively economical addition to the radiology suite with the manometry analysis available fulfilling the criteria laid down by the Clinical Associates Group of the British Society of Gastroenterology.

A pilot study of antioxidant intake in patients with cholesterol gallstones.

Whereas macronutrient intake has been extensively investigated in an attempt to unravel the pathogenesis of human cholesterol gallstones, theoretical considerations and animal models suggest that deficits in micronutrient antioxidants may be more relevant. We report a pilot study of this aspect. The plan was to obtain 7-d weighed food inventories over a 6-mo period from equal numbers of patients who had not consciously changed their diets, patients who were on low-fat diets and age- and gender-matched controls. Food tables would be used to derive daily intakes of 16 known antioxidants, essential amino acids, and essential fatty acids. Under-reporting of food intake, a recognized drawback of this dietary method, would be sought retrospectively by reference to a key publication giving minimum cut-off limits for ratios of energy intakes to basal metabolic rates. There were 18 pairs for study. Analysis of data for the 9 pairs involving patients on their normal diets showed no differences in the intakes of energy macronutrients, and cholesterol, but the patients ingested lower amounts of 10 among 16 antioxidants (P < 0.05 for methionine, alpha-tocopherol, manganese, and vitamin D; 0.05 < P < 0.10 for cysteine, beta-carotene, vitamin C, selenium, zinc, and phosphorus). Both subsets of patients ingested lower amounts of linoleic acid (diet unchanged P = 0.009, changed P = 0.026) and several essential amino acids than did matched controls. Institution of a low-fat diet caused the expected fall in intakes of energy and saturated fatty acids such that the deficit in alpha-tocopherol was amplified, but substitution of fruit and vegetables by the patients resulted in a fortuitous increase in vitamin C, beta-carotene, and manganese intake. Retrospective analysis confirmed under-reporting of food intake by all four subsets of subjects but there was no significant difference in the mean ratio of energy intake to estimated basal metabolic rate in the subset of patients who had not consciously altered their diets and the subset of matched controls. Furthermore, the lower daily intake of alpha-tocopherol and linoleic acid by these patients persisted when results were expressed relative to total fat consumption. The results support the hypothesis that insufficiency of dietary antioxidants, particularly alpha-tocopherol, may be germane to human gallstone disease; they also suggest that low intakes of linoleic acid and essential amino acids may be relevant. Because of the small sample sizes, however, these deductions should be regarded as tentative, pending confirmation by biochemical analysis of blood and especially of hepatic bile.

Critical issues in the management of gastroesophageal reflux disease.

AIM: To discuss some of the critical issues in the management of gastroesophageal reflux disease (GERD). OPINION: GERD is a chronic relapsing disease characterized by pathological exposure of the distal esophagus to gastric acid. Diagnosis of the condition can often be made on the basis of symptomatology alone. Endoscopy can help in assessing the degree of esophageal damage, influencing the choice of therapy, and should be performed at least once during a symptomatic patient's lifetime to exclude a diagnosis of Barrett's esophagus. However, endoscopy is mandatory at diagnosis if alarm symptoms are present. Treatment should aim to provide the lowest degree of acid suppression needed for the control of symptoms. Proton pump inhibitors (PPIs) represent the most cost-effective treatment option for the short- and long-term management of GERD. Compared with standard- and high-dose H2-receptor antagonists, PPIs result in superior and faster healing and symptom relief across all grades of esophagitis and are more effective at maintaining patients in symptomatic and endoscopic remission. Treatment with PPIs has also been shown to reduce the rate of recurrent stricture after initial dilatation. PPIs are generally well tolerated, and to date there have been no reports of gastric dysplasia resulting from their long-term use. Anti-reflux surgery should be reserved for patients who are unresponsive to continuous PPI therapy or perhaps for young patients. It will be several years before the impact of laparoscopic fundoplication as a cost-beneficial therapy for GERD can be assessed. CONCLUSION: The superior clinical efficacy of PPIs when compared with any other drug regimen for GERD make them the treatment of choice for the short- and long-term management of this troublesome condition.

Prospective audit of perforation rates following upper gastrointestinal endoscopy in two regions of England.

After cardiopulmonary complications, perforation is the second most important cause of complications following flexible upper gastrointestinal endoscopy. A recent audit of 14,149 procedures detected a perforation rate of 0.05 per cent (overall mortality rate 0.008 per cent) during diagnostic endoscopy, and a perforation rate of 2.6 per cent (overall mortality rate 1.0 per cent) following oesophageal intubation or dilatation. The incidence of perforation following both diagnostic and therapeutic upper gastrointestinal endoscopy has not changed over the past 10 years. The risk factors are numerous but this audit demonstrated that inexperience increases the likelihood of perforation.

Guidelines on appropriate indications for upper gastrointestinal endoscopy. Working Party of the Joint Committee of the Royal College of Physicians of London, Royal College of Surgeons of England, Royal College of Anaesthetists, Association of Surgeons, the British Society of Gastroenterology, and the Thoracic Society of Great Britain.

Upper gastrointestinal endoscopy is a valuable diagnostic tool, but for an endoscopy service to be effective it is essential that it is not overloaded with inappropriately referred patients. A joint working party in Britain has considered the available literature on indications for endoscopy, assessed standard practice through a questionnaire, and audited randomly selected cases using an independent panel of experts and an American database system. They used these data to produce guidelines on the appropriate and inappropriate indications for referral for endoscopy, although they emphasise that under certain circumstances there may be reasons to deviate from the advice given. The need for endoscopy is most difficult to judge in patients with dyspepsia, and this aspect is discussed in detail. Early endoscopy will often prove more cost effective than delaying until the indications are clearer.

Prospective audit of upper gastrointestinal endoscopy in two regions of England: safety, staffing, and sedation methods.

A prospective audit of upper gastrointestinal endoscopy in 36 hospitals across two regions provided data from 14,149 gastroscopies of which 1113 procedures were therapeutic and 13,036 were diagnostic. Most patients received gastroscopy under intravenous sedation; midazolam was the preferred agent in the North West and diazepam was preferred in East Anglia. Mean doses of each agent used were 5.7 mg and 13.8 mg respectively, although there was a wide distribution of doses reported. Only half of the patients endoscoped had some form of intravenous access in situ and few were supplied with supplementary oxygen. The death rate from this study for diagnostic endoscopy was 1 in 2000 and the morbidity rate was 1 in 200; cardiorespiratory complications were the most prominent in this group and there was a strong relation between the lack of monitoring and use of high dose benzodiazepines and the occurrence of adverse outcomes. In particular there was a link between the use of local anaesthetic sprays and the development of pneumonia after gastroscopy (p < 0.001). Twenty perforations occurred out of a total of 774 dilatations of which eight patients died (death rate 1 in 100). A number of units were found to have staffing problems, to be lacking in basic facilities, and to have poor or virtually non-existent recovery areas. In addition, a number of junior endoscopists were performing endoscopy unsupervised and with minimal training.

Pathophysiological effects of long-term acid suppression in man.

A critical evaluation has been made of the available evidence in man of the effects of prolonged low acid states on the structure and function of the stomach. Various human models have been examined. 1. Ageing does not affect acid output from the normal male stomach, and there may be an increase in women. With progressive atrophy of the corpus mucosa, which is more frequent and rapid in patients with gastric ulcer, there is an associated loss of secretory function. Chronic gastritis and atrophy are the most important age-related changes, which in many cultures are hypothesized to develop via a prior Helicobacter pylori-related gastritis. However, H. pylori colonization of the mucosa decreases with increasing grades of gastric atrophy probably because intestinal metaplasia provides a hostile environment. Atrophy and intestinal metaplasia are associated with precancerous lesions and gastric cancer. Apparent hyperplasia of the gastric argyrophil endocrine cells is a common and spontaneous phenomenon in patients with atrophic gastritis, which in part may be related to the preferential loss of nonendocrine cells. 2. Pernicious anemia is associated with a complete lack of acid production, marked hypergastrinemia, and endocrine cell hyperplasia in the majority of patients. ECL-cell carcinoids and gastric cancer occur with a prevalence of 3-7%, and endoscopic surveillance in routine clinical practice is not warranted. 3. Gastric ECL-cell carcinoids are rare events that have been described in association with two diseases in man, pernicious anemia and Zollinger-Ellison syndrome as part of multiple endocrine neoplasia syndrome type I, and usually relate to marked hypergastrinemia and the presence of chronic atrophic gastritis with gastric antibodies or a genetic defect rather than the presence or absence of acid. Regression or disappearance of ECL-cell carcinoids, either spontaneously or after removal of the gastrin drive, has been recorded. Lymph node, and rarely hepatic, metastases are documented but death in these cases has been anecdotal. 4. Therapy with H2 antagonists may result in up to a twofold rise in serum gastrin levels but in man no endocrine cell hyperplasia has been recorded. However, the data for H2 antagonists on these aspects are very limited. There is no drug-related risk of gastric or esophageal cancer, although the incidence of the latter may be raised. Long-term treatment with omeprazole is associated with a two- to fourfold increase in gastrin levels over baseline values in one third of patients and apparent endocrine cell hyperplasia in 7% of cases overall.(ABSTRACT TRUNCATED AT 400 WORDS)

Reversal of conscious sedation by flumazenil: current status and future prospects.

Flumazenil is safe and highly effective at reversing both benzodiazepine-induced sedation and amnesia. Bolus intravenous injection is the most appropriate technique when the goal is to fully reverse conscious sedation. Currently, the proven effective dose of flumazenil is 0.5 mg. For practical purposes, in this clinical setting, true resedation does not occur, and if the appropriate type and dose of agonist have been used, residual sedation is not a clinical problem. Concerns over acute anxiety reactions and precipitation of acute withdrawal syndrome in chronic benzodiazepine users remain theoretical and unsubstantiated by human data. Further clinical studies are required to determine whether the clinical practice of using flumazenil could include this group of patients. Depression of ventilatory responsiveness induced by benzodiazepines can be reversed effectively and promptly by flumazenil. Flumazenil must be immediately available as an emergency drug in any area where benzodiazepines are used. The clinical and economic benefits of elective and routine use of flumazenil have been demonstrated, but yet to gain widespread acceptance.