Laparoscopic versus minilaparotomy cholecystectomy: a randomised trial

Although laparoscopic cholecystectomy has rapidly become routine practice in the UK, there has been no rigorous comparison of it with open cholecystectomy. In our trial, 302 patients were randomised to laparoscopic or minilaparotomy cholecystectomy. Recovery after surgery was assessed by length of hospital stay, outpatient review at 10 days and 4 weeks, and patient questionnaires 1, 4, and 12 weeks after surgery. The mean operation time was 14 min shorter for minilaparotomy, while median post-operative hospital stay was 2 days shorter after laparoscopic cholecystectomy. The hospital costs were about 400 pounds greater for the laparoscopic procedure. Laparoscopic patients returned to work in the home sooner; at 1 week, they had better physical and social functioning, were less limited by physical problems, and had less pain and depression. At 4 weeks, only physical functioning and depression scores were better in the laparoscopic group, and by 3 months there were no differences. Laparoscopic patients were more satisfied with the appearance of their scars. The incidence of complications after both procedures was 20%. Compared to minilaparotomy cholecystectomy, laparoscopic cholecystectomy results in shorter hospital stay, less postoperative dysfunction, and quicker return to normal activities, but is more costly.

Bile duct injury and bile leakage in laparoscopic cholecystectomy

The introduction of laparoscopic cholecystectomy has been associated with an increased incidence of bile duct injury. This review presents the incidence of bile duct injury in reported series and examines the role of the learning curve and other contributing factors. There is good evidence to suggest that, with adequate training and experience, the incidence of biliary injury can be reduced to a level comparable to that of open cholecystectomy. Continued audit is required to ensure that the low complication rates achieved in selected centres with wide experience are reproduced by the surgical community in general.

A prospective randomised controlled clinical trial comparing somatostatin and vasopressin in controlling acute variceal haemorrhage

Twenty two patients were entered into a randomised controlled clinical trial comparing the efficacy of somatostatin and vasopressin in controlling acute variceal haemorrhage. Somatostatin was significantly more successful in controlling acute variceal haemorrhage than vasopressin (p = 0.003). Furthermore, no complications were observed during treatment with somatostatin.

Increased monocyte cytokine production in association with systemic complications in acute pancreatitis

Tumour necrosis factor (TNF) alpha, interleukin (IL) 1 beta, IL-6 and IL-8 are thought to play a central role in the pathophysiology of sepsis but their role in acute pancreatitis is unknown. In the present study, monocytes were isolated from the peripheral blood of 26 patients with moderate or severe acute pancreatitis without biliary sepsis. Secretion of these cytokines in vitro was measured at intervals during the first week of illness. Sixteen patients developed systemic complications. Peak TNF-alpha secretion was significantly higher in patients who developed systemic complications (median (interquartile range (i.q.r.)) 18.5 (5.5-28.5) ng/ml) than in those with an uncomplicated course (3.7 (2.3-6.4) ng/ml, P < 0.01). Similarly, peak IL-6 and peak IL-8 secretion were significantly higher in the complicated group (IL-6: complicated median (i.q.r.) 48.9 (12.1-71.0) ng/ml, uncomplicated 16.3 (14.2-37.9) ng/ml, P < 0.05; IL-8: complicated 748 (643-901) ng/ml, uncomplicated 608 (496-749) ng/ml), P < 0.05). No significant difference in peak IL-1 beta secretion was observed between the two groups. Systemic complications of acute pancreatitis are associated with a significant increase in monocyte secretion of TNF-alpha, IL-6 and IL-8 suggesting that, as in sepsis, these cytokines play a central role in the pathophysiology of the disease.

Obesity, metabolic syndrome and sleep apnoea: all pro-inflammatory states

Obesity is associated with significant morbidity and mortality and is increasing in prevalence worldwide. Associated conditions include insulin resistance (IR), diabetes, hypertension and dyslipidaemia; a clustering of these has recently been termed as metabolic syndrome. Weight gain is a major predictor of the metabolic syndrome with waist circumference being a more sensitive indicator than body mass index as it reflects both abdominal subcutaneous adipose tissue and visceral adipose tissue (VAT). VAT has more metabolic activity and secretes a number of hormones and pro-inflammatory cytokines which are linked with the metabolic abnormalities listed above. Central obesity also increases the risk of obstructive sleep apnoea syndrome (OSAS), where the sleep disordered breathing may also independently lead to/or exacerbate IR, diabetes and cardiovascular risk. The contribution of OSAS to the metabolic syndrome has been under-recognized. The putative mechanisms by which OSAS causes or exacerbates these other abnormalities are discussed. We propose that activation of nuclear factor kappa B by stress hypoxia and/or by increased adipokines and free fatty acids released by excess adipose tissue is the final common inflammatory pathway linking obesity, OSAS and the metabolic syndrome both individually and, in many cases, synergistically.

The bile acid deoxycholic acid (DCA) at neutral pH activates NF-kappaB and induces IL-8 expression in oesophageal cells in vitro

Barrett's oesophagus patients accumulate chromosomal defects during the histological progression to cancer, one of the most prominent of which is the amplification of the whole of chromosome 4. We aimed to study the role that the transcription factor NF-kappaB, a candidate cancer- promoting gene, present on chromosome 4, plays in Barrett's oesophagus, using OE33 cells as a model. Specifically, we wanted to determine if NF-kappaB was activated by exposure to bile acid (deoxycholic acid) in oesophageal cells. We employed pathway specific cDNA microarrays and real-time PCR, to first identify bile acid induced genes and specifically to investigate the role of NF-kappaB. An NF-kappaB reporter system was used, as well as an inhibitor of NF-kappaB (pyrrolidine dithiocarbamate) to confirm the activation of NF-kappaB by bile. We show that physiological levels of DCA (100-300 microM) were capable of activating NF-kappaB in OE33 cells and inducing NF-kappaB target gene expression (particularly IkappaB and IL-8). Other gene expression abnormalities were also shown to be induced by DCA. Importantly, preliminary experiments showed that NF-kappaB activation by bile occurred at neutral pH, but not at acid pH. Acidic bile did however cause over-expression of the c-myc oncogene, as reported previously. Hence, we present data showing that NF-kappaB may be a key mediator of carcinogenesis in bile exposed Barrett's tissues. In addition, neutral bile acids appear to play a significant part in reflux induced gene expression changes. We postulate that the activation of the survival factor NF-kappaB by bile may be linked to the previous cytogenetic data from our laboratory showing the amplification of NF-kappaB's chromosome (chromosome 4), during Barrett's cancer progression. Hence chromosome 4 amplification may provide a survival mechanism for bile exposed oesophageal tissues via NF-kappaB.

A dimethylnitrosamine-induced model of cirrhosis and portal hypertension in the rat

A method of producing cirrhosis consistently in rats by the administration of dimethylnitrosamine (DMNA) is described. Two weeks following the cessation of DMNA treatment there was distortion of the lobular architecture of the liver and some focal nodule formation. This 'pre-cirrhotic' state was accompanied by portal hypertension, biochemical abnormalities and the development of ascites. The mortality 2 weeks after cessation of DMNA was 42%. Twenty-four weeks after DMNA treatment cirrhosis had developed with diffuse nodularity and fibrosis, marked portal hypertension, and accumulation of ascites. There was also a deterioration in liver function, with hypoproteinaemia and jaundice. The overall mortality 24 weeks after the cessation of DMNA treatment had risen to 52%. This model of cirrhosis in the rat may be useful in evaluating the efficacy of drugs in the long-term management of portal hypertension in man.

Genetic pathways involved in the progression of Barrett's metaplasia to adenocarcinoma

BACKGROUND

The prediction of which patients with Barrett's metaplasia will develop cancer is difficult. Better genetic characterization of the condition may aid clinicians in devising more effective management and follow-up strategies.

METHODS

A review was undertaken of the accumulated genetic data relating to the progression of squamous epithelium to adenocarcinoma. The normal functions of a number of cancer-related genes are described and an explanation is given of how alterations in these genes interfere with normal cell processes and lead to cancer.

RESULTS AND CONCLUSION

The main genetic alterations accompanying the progression through dysplasia to adenocarcinoma were collated from 135 papers. The principal genetic changes implicated are the loss of p16 gene expression (by deletion or hypermethylation), the loss of p53 expression (by mutation and deletion), the increase in cyclin D1 expression, the induction of aneuploidy and the losses of the Rb, DCC and APC chromosomal loci.

What effect does the duration of an inguinal hernia have on patient symptoms?

BACKGROUND

Despite the fact that repair of an inguinal hernia is one of the most common operations performed in general surgery, we have very little information on the natural history of the untreated hernia. The aim of this study was to evaluate the association between hernia symptoms and the duration the patients had their hernias before presentation to a surgical outpatient department for an elective or emergency operation.

STUDY DESIGN

Data were gathered prospectively on a consecutive series of 699 patients admitted to two University Departments of Surgery for scheduled operations for an inguinal hernia.

RESULTS

More than one third (267) of patients had their hernias for 1 year or longer, up to 65 years, before presentation. The most common symptom on presentation was pain or discomfort at the hernia site, which occurred in 457 (66%) patients. The cumulative probability of pain increased with time to almost 90% at 10 years. The hernia had become irreducible in 48 patients (6.9%). The cumulative probability of irreducibility increased from 6.5% (95% confidence interval 4% to 9%) at 12 months to 30% (95% confidence interval 18% to 42%) at 10 years. Leisure activities were affected in 29% of patients although only 13% of patients had to take time off work because of hernia-related symptoms. Only two patients (0.3%) required resection of infarcted bowel or omentum.

CONCLUSIONS

Because many patients with an inguinal hernia are asymptomatic or mildly symptomatic, prospective clinical trials to assess the role of operations for such hernias are required.

A prospective randomised controlled trial comparing the efficacy of somatostatin with injection sclerotherapy in the control of bleeding oesophageal varices

Since previous reports have suggested that somatostatin may be of value in the control of acute variceal haemorrhage, we compared its efficacy with that of injection sclerotherapy in a randomised controlled clinical trial. Eighty consecutive patients with endoscopically-proven severe variceal bleeding were randomised to injection sclerotherapy (n = 41) or somatostatin (n = 39) given as a continuous infusion of 250 micrograms/h for 5 days plus daily bolus administration of 250 micrograms. The efficacy of injection sclerotherapy and somatostatin infusion in controlling haemorrhage and preventing rebleeding (censored at 5 days), mortality (censored at 28 days) and complications was compared. The aetiology of the portal hypertension and transfusion requirements was similar between the two groups, but there were more patients with severe liver disease (Child's C) in the somatostatin group. There was no significant difference between the two treatments in the initial (p = 1.0) or overall control of bleeding (p = 0.58). Furthermore, somatostatin was as effective as injection sclerotherapy in controlling bleeding in patients with severe liver disease or in those actively bleeding at the time of their endoscopy. The relative risk of rebleeding whilst receiving somatostatin compared to injection sclerotherapy was 1.39 [95% Confidence Interval (CI) 3.73; 0.52], but this was reduced to 0.98 (95% CI 0.37; 2.67) when readjusted for Child's grading, the only prognostic factor shown to be of significance. Mortality was not significantly different between the two groups of patients (p = 0.31). The relative risk of dying whilst receiving somatostatin compared to injection sclerotherapy was 1.6 (95% CI 3.93; 0.66) but was reduced to 1.03 (95% CI 0.47; 2.47) when adjusted for Child's grading, the only significant prognostic factor. Complications in the somatostatin group were minor and less frequent than after injection sclerotherapy. The results of this study indicate that somatostatin is a safe treatment, which is as effective an endoscopic injection sclerotherapy for acute variceal bleeding.

Prospective placebo-controlled randomized trial of lexipafant in predicted severe acute pancreatitis

BACKGROUND

Many patients with severe acute pancreatitis develop organ system failure during the first few days of illness, and this accounts for the majority of early deaths. No specific therapy is available and treatment remains supportive.

METHODS

In a randomized controlled trial conducted in 11 hospitals in the West of Scotland, 50 patients with predicted severe acute pancreatitis were selected from 188 screened over a 14-month period. Patients received placebo or lexipafant, a potent platelet-activating factor antagonist, by continuous intravenous infusion at a dose of 100 mg/day for up to 7 days. Early systemic complications were assessed by the measurement of organ failure scores.

RESULTS

There was a significantly greater fall in organ failure score in the treatment group during the 7 days of study (mean and median changes in organ failure score were 0.17 and 0 in the placebo group versus -1.42 and -1 in the treatment group; P = 0.003, Wilcoxon rank sum test), associated with trends towards a reduction in mortality and a reduced incidence of systemic complications.

CONCLUSION

These results suggest that lexipafant may be a useful adjunct to full supportive care in the early management of patients with severe acute pancreatitis.

Early outcome after open versus extraperitoneal endoscopic tension-free hernioplasty: a randomized clinical trial

BACKGROUND

The use of minimal access surgery for repair of groin hernias is controversial. The aim of this study was to compare endoscopic tension-free hernia repair with open tension-free hernia repair within a randomized clinical trial.

METHODS

One hundred twenty patients were randomized by four surgeons during a 1-year period. Early outcome measures were then analyzed by intention to treat.

RESULTS

Median postoperative pain scores (63 [interquartile range (IQR), 23 to 81] versus 35 [IQR, 17 to 62]; p = 0.004) and analgesia requirements (2.5 [IQR, 2 to 4] doses verus 2.0 [IQR, 1 to 3] doses; p = 0.0008) were significantly less for patients undergoing endoscopic hernia repair. Hospital stay (1 [IQR, 0 to 1] day versus 2 [IQR, 1 to 2] days; p < 0.0001) was also significantly reduced for the endoscopic group. Wound complications occurred significantly more frequently in the open group. No difference in pulmonary function or metabolic response to trauma (interleukin-6, C-reactive protein, glucose, albumin) was observed between the groups.

CONCLUSIONS

This study shows significant short-term advantages for endoscopic tension-free repair over open tension-free repair. However, larger studies with a longer follow-up period are required to establish the relative merits of both procedures in the management of patients with groin hernias.

Effects of somatostatin and a long-acting somatostatin analogue on the prevention and treatment of experimentally induced acute pancreatitis in the rat

The effects of somatostatin (SRIF) and its long-acting analogue, SMS 201-995 on the prevention and treatment of acute pancreatitis were studied in rats. Acute pancreatitis was established by ligating the bile duct at the point of entry into the duodenum, thereby allowing reflux of bile into the pancreas. Administration of SRIF (4 micrograms kg-1 body wt IV followed by a 12 h infusion of 4 micrograms kg-1 body wt h-1) or SMS 201-995 (2 micrograms kg-1 body wt SC) at the time of bile duct ligation prevented the increase in the serum concentrations of amylase and lipase observed in control rats 12 h after bile duct ligation. Moreover, SRIF and SMS 201-995 administration prevented development of the histological changes consistent with acute pancreatitis observed in control animals. These results suggest that SRIF or SMS 201-995 may be of value in preventing acute pancreatitis following ERCP or after surgery on the pancreas. In rats with established pancreatitis, SRIF (IV bolus of 4 micrograms kg-1 body wt followed by a 24 h continuous infusion of 4 micrograms kg-1 body wt h-1) or SMS 201-995 (2 micrograms kg-1 body wt SC followed by a similar dose 12 h later): (1) significantly improved survival; (2) produced histological changes in the pancreas consistent with organization and healing; (3) prevented the accumulation of ascitic fluid; (4) reduced the serum levels of amylase and lipase. These results suggest that SRIF and SMS 201-995 may prove valuable in the treatment of established acute pancreatitis in man.

The bile acid deoxycholic acid has a non-linear dose response for DNA damage and possibly NF-kappaB activation in oesophageal cells, with a mechanism of action involving ROS

Deoxycholic acid (DCA) is a secondary bile acid implicated in various cancers of the gastrointestinal (GI) tract. In oesophageal adenocarcinoma, DCA is believed to contribute to carcinogenesis during reflux where stomach contents enter the lower oesophagus. It is imperative that we understand the mechanisms whereby oesophageal carcinogens function in order that therapeutic options may be developed. We have previously shown that DCA can damage chromosomes and does so through its generation of reactive oxygen species (ROS). We show here, after detailed experiments, that DCA appears to have a non-linear dose response for DNA damage. DCA induces DNA damage (as measured by the micronucleus assay) at doses of 100 microM and higher in oesophageal OE33 cells, but fails to induce such DNA damage below this cut-off dose. We also show that in terms of NF-kappaB activation (as measured by up-regulation of two NF-kappaB target genes) by DCA, a similar dose response is observed. This dose-response data may be important clinically as DCA exposure to the oesophagus may be used as a way to identify the 10% of Barrett's oesophagus patients currently progressing to cancer from the 90% of patients who do not progress. Only quantitative studies measuring DCA concentrations in refluxates correlated with histological progression will answer this question. We further show here that ROS are behind DCAs ability to activate NF-kappaB as antioxidants (epigallocatechin gallate, resveratrol and vitamin C) abrogate DCAs ability to up-regulate NF-kappaB-controlled genes. In conclusion, low doses of DCA appear to be less biologically significant in vitro. If this were to be confirmed in vivo, it might suggest that reflux patients with low DCA concentrations may be at a lower risk of cancer progression compared to patients with high levels of DCA in their refluxate. Either way, antioxidant supplementation may possibly help prevent the deleterious effects of DCA in the whole GI tract.

Comparison of metabolic responses to laparoscopic and minilaparotomy cholecystectomy

This randomized study compared the metabolic responses to laparoscopic cholecystectomy (n = 10) and minilaparotomy cholecystectomy with a 5-7-cm incision (n = 10). Venous blood samples were taken before operation and at 3, 6, 9, 12, 18, 24, 48, 72 and 168 h after incision and analysed for levels of C-reactive protein, interleukin 6, cortisol, albumin, transferrin, iron, fibrinogen, fibrin degradation products and polymorphonuclear elastase, and for neutrophil and lymphocyte counts. Urine samples (24 h) were analysed for urea, creatinine, 3-methylhistidine and catecholamines. The magnitude of the metabolic changes from baseline levels was quantified by calculating areas under each individual curve. A significant metabolic response with a similar time course and magnitude of changes occurred after laparoscopic and minilaparotomy cholecystectomy but with wide variation in magnitude between individuals.

Chromosome 4 hyperploidy represents an early genetic aberration in premalignant Barrett's oesophagus

BACKGROUND AND AIMS

Characterisation of the underlying molecular mechanisms that promote Barrett's progression may ultimately lead to identification of potential predictive genetic markers that classify patients' malignant risk. In an attempt to understand these causative pathways, fluorescence in situ hybridisation (FISH) was used in this study to determine when specific genetic alterations arise during Barrett's associated neoplastic progression.

METHODS

Endoscopic cytology brushings were obtained from 28 patients with Barrett's metaplasia, 28 with dysplasia (20 low grade dysplasia (LGD) and eight with high grade dysplasia (HGD)), and seven with adenocarcinoma, together with paired control brushings from regions of normal proximal squamous cell epithelium. The exfoliated epithelial cells were washed and deposited onto slides. Probes specific for the centromeres of chromosomes 4, 8, 20, and Y, and locus specific probes for the tumour suppressor genes p16, p53, and Rb were subsequently hybridised.

RESULTS

Aneuploidy was found early in progression, with metaplastic tissues displaying increased copy numbers of chromosomes 4 and 8. Chromosome 4 hyperploidy was found in 89%, 90%, 88%, and 100% of metaplasias, LGD, HGD, adenocarcinomas, respectively, while chromosome 8 hyperploidy occurred in 71%, 75%, 100%, and 100% of patients with the respective staging. Loss of the p16 tumour suppressor gene also presented in metaplastic epithelium (7%) but most other genetic aberrations were only seen in HGD.

CONCLUSIONS

Genetic instability arises well before dysplasia in Barrett's oesophagus, with chromosome 4 and 8 hyperploidy representing the earliest and most common alterations identified. As these aberrations are widespread at all the premalignant stages, there may be genes on chromosomes 4 and 8 that are involved in both the initiation and progression of Barrett's oesophagus.

Neoterminal ileal blood flow after ileocolonic resection for Crohn's disease

Endoscopic laser Doppler flowmetry was used to measure neoterminal ileal blood flow in 16 patients who had undergone ileocolonic resection for Crohn's disease and had since remained clinically and biochemically free of disease, and eight control patients who had undergone similar surgery for colonic carcinoma. Four patients with clinically active Crohn's disease of the terminal ileum were also studied. Neoterminal ileal recurrence in those with inactive Crohn's disease was graded endoscopically. The median and minimum of five local blood flow measurements performed in each patient were inversely correlated with the endoscopic recurrence grade (r = -0.52, p = 0.04 and r = -0.63, p = 0.01 respectively). Relative to the control group, median blood flow was non-significantly lower in the inactive Crohn's disease group as a whole (p > 0.05) but was significantly reduced in patients with active disease (p = 0.02). A progressive reduction in tissue perfusion may accompany recurrence of Crohn's disease while at a subclinical stage.

Parathyroid carcinoma

BACKGROUND

Parathyroid carcinoma is a rare malignancy affecting 0.5-5 per cent of all patients with primary hyperparathyroidism. This article reviews the literature on the pathogenesis, pathology, clinical features, diagnosis and management of parathyroid carcinoma.

METHODS

A Medline search was performed and all relevant English language articles published between 1970 and 2005 were retrieved. The search words included 'parathyroid carcinoma', 'pathology', 'genetics', 'management' and 'radiotherapy'. Secondary references were obtained from key articles.

RESULTS AND CONCLUSION

The exact aetiology of parathyroid carcinoma remains obscure. Recently, the HRPT2 gene has been implicated in its pathogenesis and may prove to be a genetic target in future. Surgical resection is the accepted 'gold standard'. There is now a growing consensus on the use of adjuvant radiotherapy as it has been shown to provide a survival benefit.

Effects of a somatostatin analogue SMS 201-995 on hepatic haemodynamics in the pig and on intravariceal pressure in man

The effects of a somatostatin analogue, SMS 201-995, on hepatic haemodynamics in the pig and on intravariceal pressure in man were studied. An infusion of 250 micrograms/h SMS 201-995 significantly reduced portal pressure, portal venous flow and hepatic artery flow in the pig. These changes in hepatic haemodynamics were accompanied by a reduction in cardiac output, a reflex slowing of the heart and an increase in arterial blood pressure. Splanchnic vascular resistance was increased following SMS 201-995 administration but hepatic vascular resistance remained unchanged. Administration of 50 micrograms SMS 201-995 reduced the intravariceal pressure from 27.4 +/- 2.5 to 15.8 +/- 2.1 mmHg in 9 patients with cirrhosis and portal hypertension. Administration of 50 micrograms SMS 201-995 also reduced portal pressure from 29 to 22 mmHg in a patient undergoing an elective portacaval shunt. These results suggest that SMS 201-995 may be of value in the control of bleeding oesophageal varices. Furthermore, because of its prolonged duration of action SMS 201-995 may be useful in the long term management of portal hypertension in patients with cirrhosis.

Symptomatic outcome 1 year after laparoscopic and minilaparotomy cholecystectomy: a randomized trial

In a randomized controlled trial, 299 patients were sent a symptoms questionnaire 1 year after laparoscopic (n = 151) or minilaparotomy (n = 148) cholecystectomy for symptomatic cholelithiasis. The response rate to the questionnaire from contactable patients was 86 per cent. In both groups, at least 90 per cent of patients reported that their symptoms were improved, and at least 93 per cent rated the success of their operation as 'excellent', 'good', or 'fair'. However, over half the patients reported abdominal pain, a quarter reported flatulence, and a quarter dyspepsia. The only difference between treatment groups was that a higher proportion of patients who underwent minilaparotomy reported heartburn (35 per cent versus 19 per cent, P = 0.005). Patients who reported a 'poor' outcome were more likely to have suffered a postoperative complication, had lower quality of life scores, and higher anxiety and depression scores. Both laparoscopic and minilaparotomy cholecystectomy result in symptomatic benefit in at least 90 per cent of patients with symptomatic cholelithiasis.

Relationship of carotenoid and vitamins A and E with the acute inflammatory response in acute pancreatitis

BACKGROUND

Inflammation and oxidative stress are believed to be important in the development of the systemic complications of acute pancreatitis. The fat-soluble vitamins A and E, and the carotenoids have antioxidant properties. The aim of this study was to assess the effect of acute pancreatitis on serum concentrations of vitamin antioxidants and to relate such changes to the degree of the inflammatory response.

METHODS

Thirteen consecutive patients with predicted severe acute pancreatitis were compared with 26 matched healthy controls. Five patients developed severe acute pancreatitis and three of these died. Vitamin antioxidant and C-reactive protein (CRP) levels were measured daily for up to 7 days.

RESULTS

Patients had significantly lower levels of antioxidants throughout the course of the study (P < 0.017). In patients there was a significant correlation between peak CRP and trough antioxidant levels (P < 0. 01). In patients with mild acute pancreatitis, the concentrations of retinol and beta-carotene at final review were significantly higher than those in patients with severe acute pancreatitis (P < 0.05). This coincided with a reduction in CRP level.

CONCLUSION

In acute pancreatitis, circulating concentrations of vitamin antioxidants are reduced and are inversely related to the rise in CRP level.

Ventilatory and blood gas changes during laparoscopic and open cholecystectomy

As part of a randomized trial, ventilatory and arterial blood gas changes were assessed during open (n = 30) and laparoscopic (n = 30) cholecystectomy. Measurements were made during anaesthesia before the start of surgery and at the time of removal of the gallbladder. Despite an increase in minute ventilation from a mean(s.d.) of 5.7(1.4) to 6.1(1.2) litres, mean(s.d.) arterial carbon dioxide tension (PaCO2) rose from 5.3(0.9) to 6.0(0.9) kPa during laparoscopic cholecystectomy. End-tidal carbon dioxide tension (PE'CO2) had poor precision in predicting PaCO2 (95 per cent interval of agreement -0.61 to 1.93 kPa). Mean(s.d.) peak airway pressure increased from 17(4) to 23(4) cmH2O. The mean PaCO2--PE'CO2 value did not change significantly, although there was significant within-patient variation. Arterial oxygen levels did not change significantly. By comparison, no clinically significant changes in ventilation or blood gas values occurred during open cholecystectomy. In conclusion, laparoscopic cholecystectomy requires a substantial but variable increase in minute ventilation to compensate for carbon dioxide absorption from the peritoneum.