Gastro-oesophageal reflux associated with nocturnal gastric acid breakthrough on proton pump inhibitors

BACKGROUND: Nocturnal gastric acid breakthrough, defined as intragastric pH < 4 for more than 1 h in the overnight period, is observed in up to 70% of normal subjects on proton pump inhibitors taken twice daily. The frequency of this breakthrough in patients with gastro-oesophageal reflux and accompanying oesophageal reflux during this period has not been studied. AIM: To examine the frequency of nocturnal break-through and accompanying oesophageal acid exposure in patients with gastro-oesophageal reflux treated with proton pump inhibitors twice daily. METHODS: Prolonged ambulatory pH records from 76 patients on twice daily proton pump inhibitors between January 1991 and July 1997 were analysed for the presence of nocturnal gastric acid breakthrough and accompanying oesophageal pH < 4. Studies from 31 normal subjects on twice daily proton pump inhibitors constituted the control group. RESULTS: Nocturnal gastric acid breakthrough was seen in 70% of 61 patients with gastro-oesophageal reflux, 80% of 15 patients with Barrett's oesophagus and 67% of normal controls (P=N.S.). Oesophageal acid exposure was seen in 33% of gastro-oesophageal reflux patients, 50% of Barrett's oesophagus patients and 8% of normal controls (P < 0.03). No difference was found between patients taking omeprazole or lansoprazole. CONCLUSION: Nocturnal acid breakthrough is frequently seen on proton pump inhibitors twice daily and is often accompanied by oesophageal reflux. This has important implications for medical therapy in patients with severe gastro-oesophageal reflux and Barrett's oesophagus.     

Occupational Health Research in Developing Countries: The Experience in Ecuador

We report the results of a double-blind, placebo-controlled trial in nine cystic fibrosis (CF) subjects receiving cationic liposome complexed with a complementary DNA encoding the CF transmembrane conductance regulator (CFTR), and six CF subjects receiving only liposome to the nasal epithelium. No adverse clinical effects were seen and nasal biopsies showed no histological or immuno-histological changes. A partial restoration of the deficit between CF and non-CF subjects of 20% was seen for the response to low Cl- perfusion following CFTR cDNA administration. This was maximal around day three and had reverted to pretreatment values by day seven. In some cases the response to low Cl- was within the range for non-CF subjects. Plasmid DNA and transgene-derived RNA were detected in the majority of treated subjects. Although these data are encouraging, it is likely that transfection efficiency and the duration of expression will need to be increased for therapeutic benefit.     

Detection of neuroblastoma in the bone marrow: biopsy versus aspiration

OBJECTIVES: To determine the clinical effects of a change from postural drainage (PD) to positive expiratory pressure chest physiotherapy (PEP) in children with cystic fibrosis (CF) and symptoms of gastro-oesophageal reflux (GOR). To measure the effects of PD on GOR in children with CF. METHODS: Study 1: Six adolescents with CF and symptoms of GOR during PD were changed to upright PEP physiotherapy. The effects on lung function, reflux symptom scores and annual hospital days were measured. Study 2: Twenty-four children with CF (mean age 11 years) and symptoms suggestive of GOR underwent 24-h pH monitoring, including periods of chest physiotherapy. RESULTS: Study 1: All six patients reported a reduction in reflux symptoms during PEP therapy (P < 0.001). Lung function parameters improved during the first 6 months of PEP (P < 0.001). This improvement was sustained for a further 18 months. Annual hospital days decreased significantly (P < 0.0005). Study 2: Nine of 24 patients (37.5%) had pathological GOR. Reflux episodes were significantly increased during PD (P < 0.0001), as was fractional reflux time (P < 0.01). CONCLUSIONS: Upright PEP physiotherapy may be more appropriate than PD in selected patients with CF and symptomatic GOR. The role of GOR as a cofactor in the progression of pulmonary disease in CF needs further evaluation.     

Circulating transferrin receptor assay--coming of age

Gastro-oesophageal reflux (GOR) occurs frequently in children with cystic fibrosis (CF) but has not been studied in adult CF. We surveyed such symptoms by structured questionnaire in 50 adult CF patients (mean age 26 years, range 16-50; 24 male) and performed oesophageal manometry and 24-hour pH recording in 10 who had reflux symptoms (mean age 28 years, range 21-35; 8 men). 47 patients (94%) had upper gastrointestinal symptoms: 40 (80%) heartburn (27 worse when supine); 26 (52%) regurgitation; and 28 (56%) dyspepsia. At oesophageal manometry, lower oesophageal sphincter barrier pressure (LOSBP) was subnormal in 6 of the 10 patients and 3 had uncoordinated peristalsis in the mid oesophagus. 8 patients had raised DeMeester scores, indicating significant GOR. Those patients with a LOSBP < 5mm Hg had a higher DeMeester score (mean 81.0, range 47.9-128.8) than the patients with a normal LOSBP (26.9, 8.7-56.5; p < 0.002). These results show that adult CF patients have high rates of GOR symptoms, diminished LOSBP, and acid reflux.     

Decreased expression of the cystic fibrosis transmembrane conductance regulator protein in remodeled airway epithelium from lung transplanted patients

The absence or mislocalization of cystic fibrosis transmembrane conductance regulator (CFTR) is regarded as being specific for cystic fibrosis (CF). In principle, the supply of a non-CF lung transplant to a CF patient should bring up normal CFTR expression in the lower airways. Immunolocalization of CFTR and of epithelial differentiation markers (ie, cytokeratins 13, 14, and 18, and desmoplakins 1 and 2) was carried out on 21 mucosal biopsies from the upper lobe of grafts in non-CF (n = 12) and CF patients (n = 9) retrieved between days 23 and 1,608 after lung transplantation. Biopsy specimens from seven non-CF and four CF patients presented either a pseudostratified respiratory epithelium or slight basal cell hyperplasia. CFTR was distributed at the apical membrane of the ciliated cells. In remodeled epithelia with basal cell hyperplasia or squamous metaplasia, CFTR was either weakly expressed in the cytoplasm of the superficial epithelial cells or was undetectable. The extent of epithelium remodeling was significantly correlated with an impairment of lung function. The results suggest that posttransplant airway epithelium dedifferentiation of the graft leads to the loss of properly targeted CFTR irrespective of the underlying disease of the recipient.     

A comparative study of cisapride and ranitidine at controlling oesophageal acid exposure in erosive oesophagitis

BACKGROUND: The severity of gastro-oesophageal reflux disease is generally considered to be related to the extent of oesophageal acid exposure. Current therapies include antisecretory and prokinetic agents. We compared two of these, ranitidine and cisapride, in their ability to lower oesophageal acid exposure in patients with erosive oesophagitis. METHODS: Seven patients with Savary-Miller's grade II-IV oesophagitis and with oesophageal contact time > or = 8% were studied. Mean lower oesophageal sphincter pressure was 4.6 mmHg. Oesophageal acid contact time was 25.6 +/- 5.6%. Each patient received ranitidine 150 mg b.d., ranitidine 150 mg q.d.s., or cisapride 10 mg q.d.s. in a randomized 3-way cross-over design. Intra-oesophageal pH was monitored during 24 h for each of these treatments in a controlled hospital environment, while consuming a high fat, high calorie diet. RESULTS: Cisapride and ranitidine at both doses decreased the acid contact time and the number of reflux episodes. However, a minority of patients treated with ranitidine, and none with cisapride, diminished their oesophageal acid contact time to a normal value of < 5%. No treatment significantly decreased nocturnal acid exposure. CONCLUSION: In patients with severe gastro-oesophageal reflux disease both cisapride and ranitidine demonstrably lower oesophageal acid exposure, but neither therapy predictably normalizes it.     

Is functional dyspepsia largely explained by gastro-oesophageal reflux disease?

Functional dyspepsia is a chronic disorder of unknown aetiology. The lack of endoscopic abnormalities in patients with this disorder has led many physicians to believe that gastro-oesophageal reflux disease may be responsible for most symptoms. Our group has addressed this issue, by pathophysiological studies in a large cohort of Dundee patients with persistent dyspeptic symptoms. Peptic ulcer and gallstones were excluded in all patients by appropriate tests. Ambulatory pH monitoring showed oesophageal acid reflux that lay above the conventional diagnostic threshold in approximately 20% of patients. This subset was diagnosed as having gastro-oesophageal reflux disease. In the remainder, moderate or severe reflux-like symptoms were reported by approximately 44% patients, who were categorized as reflux-like functional dyspepsia. Reflux symptoms were mild or absent in 36% patients, who were categorized as non-reflux-like dyspepsia. While oesophageal pH profiles lay within the conventional normal range in both of these functional dyspepsia subgroups, patients with reflux-like functional dyspepsia had significantly greater acid exposure values, including total oesophageal acid exposure time, percentage time at a pH of less than 4.0, DeMeester scores and pain reflux event correlation. Hence patients with reflux-like functional dyspepsia have oesophageal acid exposure that lies below the diagnostic threshold for gastro-oesophageal reflux disease but exceeds that of patients with non-reflux dyspepsia. The high pain/reflux event correlation in reflux-like functional dyspepsia suggests that subthreshold oesophageal acid exposure may be associated with troublesome reflux symptoms.     

Effect of prokinetics in children with recurrent nocturnal retrosternal pain

BACKGROUND: Children rarely present with vague complaints of nocturnal recurrent retrosternal or upper-abdominal, epigastric, pain. Dysmotility of the upper gastrointestinal tract, including gastro-oesophageal reflux, might be at the origin of these manifestations. OBJECTIVE: To evaluate the clinical effect of prokinetics (cisapride) in children with recurrent nocturnal retrosternal pain, and to measure the effect of cisapride with a combined oesophageal ambulatory 24 h pH and pressure monitoring. PATIENTS: Twelve children, mean age 9.5 years (range 4.1-14.0 years), with nocturnal recurrent retrosternal pain for more than 6 months, occurring at least three times a week. METHODS: Single-blinded prospective study, with two periods of 2-3 weeks during which cisapride was administered, alternated with two placebo periods of the same duration. Clinical evaluation, and assessment with oesophageal pH and pressure monitoring. RESULTS: Cisapride was related to a temporary relief of the symptoms in 10/12 children. The improvement was demonstrated through a normalization of pH monitoring, and an increase in amplitude and duration of the contractions in the lower oesophagus. CONCLUSION: Cisapride improves complaints of recurrent nocturnal retrosternal pain in children.     

Gastro-oesophageal reflux during anaesthesia in the dog: the effect of age, positioning and type of surgical procedure

Lower oesophageal pH was monitored in 270 dogs under anaesthesia. There were 47 episodes of gastro-oesophageal reflux (17.4 per cent), most of which occurred shortly after the induction of anaesthesia. The refluxate was usually acid (pH < 4.0), but in four of the episodes (8.5 per cent) it was alkaline (pH > 7.5). Gastric contents with a pH below 2.5 were refluxed on 27 occasions (10 per cent) for an average period of about 44 minutes. Regurgitation occurred in two of the dogs. Increased age seemed to be associated with an increased incidence of reflux and an increased gastric acidity. Body position (sternal, dorsal and left or right lateral) and the tilt of the body during surgery (horizontal or tilted to an 8 degrees head-up or head-down position) had no influence on the incidence of gastro-oesophageal reflux. Dogs undergoing intra-abdominal surgery had significantly more reflux episodes than dogs undergoing non-abdominal surgery.     

Oesophageal acid clearance in patients with severe reflux oesophagitis

Previous studies examining oesophageal acid clearance have employed a variety of techniques to induce or simulate acid reflux. Clearance abnormalities have been deduced from abnormal standard motility studies, barium radiology or from 24-h pH recordings. In this study a 24-h pH and oesophageal motility recording system was used to study naturally occurring acid reflux episodes in control subjects and in two groups of patients with severe acid reflux disease (erosive oesophagitis and oesophageal stricture). Acid clearance was compared between the subject groups. Patients with oesophageal stricture were found to have poor oesophageal peristaltic ability and particularly poor oesophageal acid clearance. Those with erosive oesophagitis had normal peristaltic swallowing but abnormal acid clearance. This study has characterized, for the first time, the abnormalities in acid clearance during naturally occurring acid reflux episodes in patients with severe reflux disease. A more complete understanding of these clearance abnormalities could influence future medical and surgical strategies in the management of severe gastro-oesophageal reflux disease.     

Evaluation of the antireflux mechanism following laparoscopic fundoplication

BACKGROUND: Laparoscopic Nissen fundoplication is an effective procedure for the treatment of gastro-oesophageal reflux disease (GORD), but the underlying motility mechanisms that explain the success of this operation remain unclear. METHODS: Twenty patients with a history of GORD underwent stationary oesophageal manometry and prolonged ambulatory pH monitoring, both before and 3 months after fundoplication. RESULTS: Eighteen patients were completely cured of reflux symptoms and stopped all antireflux medication after operation. After fundoplication there was a significant increase (P < 0.01) in median resting lower oesophageal sphincter (LOS) pressure and length. Median residual LOS pressure during swallow-induced LOS relaxation also increased significantly after operation (P < 0.01). The number of reflux episodes decreased from a median of 48 to 3 after fundoplication (P < 0.01). The time at pH less than 4 decreased from 5.7 to 0 per cent in the supine position (P < 0.01), and from 9.8 to 0.2 per cent while upright (P < 0.001). CONCLUSION: Early subjective results at 3 months following laparoscopic antireflux surgery show improved symptoms. One of the mechanisms underlying the antireflux action of fundoplication is an increase in median residual LOS pressure at the gastro-oesophageal junction. This may be a purely mechanical effect of the fundic wrap extrinsic to the LOS.     

Efficacy of anterior, posterior and total fundoplication in an experimental model

BACKGROUND: This study examined the effect of different types of laparoscopic fundoplication on an incompetent lower oesophageal sphincter to test their effectiveness at preventing gastro-oesophageal reflux in the early postoperative period. METHODS: An experimental porcine model was used. Initial oesophageal myotomy ensured an incompetent lower oesophageal sphincter with free reflux of 'intragastric fluid'. Anterior, posterior or total fundoplication was then performed laparoscopically in 15 laboratory pigs (five in each group). Fundoplication competence and efficacy were determined 2 weeks after laparoscopic antireflux surgery by inflating the stomach with liquid through a gastrostomy cannula. Some animals were also studied at 4 and 6 weeks. Lower oesophageal sphincter pressure was determined using a water-perfused oesophageal manometry catheter incorporating a Dent sleeve. RESULTS: All three types of fundoplication produced similar increases in postoperative resting lower oesophageal sphincter pressure and restored adequate competence to the gastro-oesophageal junction. CONCLUSION: All three variants of laparoscopic fundoplication restore gastro-oesophageal competence in the early postoperative period.     

Abnormal gastro-oesophageal reflux in Chinese with atypical chest pain

Although atypical chest pain has been well described in the Western population, its frequency in Chinese is unknown. Over a period of 42 months, we studied 521 Chinese patients with chest pain and identified 108 patients (20.7%) whose pain was not related to cardiac causes, as determined by exercise ECG or cardiac catheterization. Using 24 h ambulatory pH monitoring and baseline oesophageal manometry, 28.7, 19.4 and 5.6% of these patients were found to have abnormal reflux parameters, abnormal manometric findings or both, respectively. There were significantly more patients complaining of chest pain during the study in the gastro-oesophageal reflux disease (GERD) group than in the non-GERD group (16/31 vs 20/77; P < 0.001). The lower oesophageal sphincter pressure was lower in those with abnormal reflex parameters than in those with normal reflux parameters (12.7 +/- 5.4 vs 17.8 +/- 5.8 mmHg; P < 0.05). There was no significant difference in symptoms, such as heartburn (54.8 vs 42.9%), regurgitation (38.7 vs 35.1%) and dysphagia (19.4 vs 24.7%), among the two groups. Non-specific changes were the most frequent baseline motility pattern. In conclusion, atypical chest pain and gastro-oesophageal reflux disease are not uncommon in Chinese and this deserves special emphasis as the continuation of anti-anginal drugs may aggravate their condition.     

Are frequent short gastro-oesophageal reflux episodes the cause of symptoms in patients with non-ulcer dyspepsia responding to treatment with ranitidine?

BACKGROUND: Patients with non-ulcer dyspepsia (NUD) responding to treatment with H2-receptor antagonists have no clinically useful characteristics. This trial compares the gastro-oesophageal reflux pattern as measured by 24-h oesophageal pH monitoring in patients responding to ranitidine with that of non-responders. METHODS: Thirty-one patients with NUD were randomized to 6 weeks' double-blind alternating treatment with 150 mg ranitidine twice daily or placebo and classified as responders or non-responders. RESULTS: Pathologic gastro-oesophageal reflux was seen in 3 of the 13 responders and 4 of the 18 no-responders (NS). The responders had frequent short reflux episodes (< 1 min in duration). When 4 patients with > or = 5 reflux episodes longer than 5 min were excluded, the number of short reflux episodes (median) in responders and non-responders was 32 and 14, respectively. The difference is statistically significant (p = 0.025). There were no other differences between the groups. CONCLUSIONS: In this study patients with NUD responding to ranitidine were characterized by frequent short reflux episodes in the absence of numerous long reflux episodes.     

Prolonged ambulatory oesophageal pH and pressure recording in healthy adults in Singapore

BACKGROUND/AIM OF STUDY: Data on prolonged ambulatory oesophageal pH and pressure monitoring in normal subjects in the East are limited. This study aimed to define the normal characteristics of ambulatory oesophageal pH and motility among healthy adults in Singapore. METHOD: Prolonged ambulatory oesophageal pH and pressure recording was performed on 10 healthy volunteers using a one-channel pH probe, a two channel pressure probe, a portable digital data recorder and a computerised data analysis system. The median (range) number of episodes with pH < 4 and the percentage of total time with pH < 4 were 24% (4%-56%) and 3.0% (0.2%-4.0%) respectively. They were greater in the upright than supine positions. RESULTS: The median percentages of peristaltic and simultaneous contractions were 65.8%-80.5% and 10.6%-12.7% respectively. The frequency, amplitude and duration of peristaltic contractions were greater during mealtimes than between meals in the upright position. CONCLUSION: This study provides the first data on prolonged ambulatory oesophageal pH and manometry in healthy Singaporean adults.     

Esophageal cancer on the increase. Is Barrett esophagus the cause?

At the Dept of Surgery, Lund University, during the 10-year period 1985-95, 54 patients with adenocarcinoma of the gastro-oesophageal junction (17 with Barrett's epithelium, and 37 without) underwent oesophageal resection: oesophagectomy and gastric pull-up (n = 10), extended total gastrectomy (n = 37), or oesophageal resection and interposition of colon (n = 2) or jejunum (n = 5). Hospital mortality was 3.7% (2/54), and the mean duration of hospitalisation 13 days (range, 9-42). Long-term survival was significantly better in the Barrett's oesophagus subgroup than in the carcinoma of the cardia (non-Barrett's oesophagus) subgroup, the respective rates being 50% vs. 10% (p = 0.0052; Log rank test). The better survival in the Barrett's oesophagus subgroup is probably to be explained by the earlier stage of disease among these patients, in turn due to a history of gastro-oesophageal reflux, whereas the predominant symptom in the cardia carcinoma subgroup was dysphagia.     

Ca2+ homeostasis in the agonist-sensitive internal store: functional interactions between mitochondria and the ER measured In situ in intact cells

OBJECTIVE: To assess the incidence of pseudomonal infection, colonization, and inflammation in the allograft of lung transplant recipients with cystic fibrosis (CF) as compared with recipients with other end-stage lung disease. DESIGN: Retrospective review. SETTING: University medical center transplant service. PATIENTS: All patients with CF and chronic pseudomonal infection (n=62) and patients with nonseptic end-stage lung disease (n=52) receiving a double lung transplant between October 1983 and March 1996. RESULTS: Fifty lung transplant recipients with CF survived beyond postoperative day (POD) 15 and were subject to sequential bronchoscopy with BAL. Forty-four CF lung transplant recipients had Pseudomonas isolated from the allograft by median POD 15 as compared with 21 non-CF lung transplant recipients (p<0.001) with isolation at median POD 158 (p<0.0001). Thirteen CF lung transplant recipients had histologic evidence of infection when Pseudomonas was isolated as compared with only three of the non-CF lung transplant recipients (p<0.01). These infections occurred earlier in the CF lung transplant recipients (median POD 10 vs 261) (p<0.01). When compared with non-CF lung transplant recipients, CF lung transplant recipients with Pseudomonas isolated but without concomitant histologic infection (colonized) were demonstrated to have increased number of polymorphonuclear cells (PMNs) in the BAL fluid recovered from the allograft (17.66+/-24.94 x 10(6) cells vs 3.46+/-4.73 x 10(6)) (p<0.05). Non-CF lung transplant recipients who became colonized with Pseudomonas also had a greater number of PMNs recovered when compared with non-CF lung transplant recipients who did not have Pseudomonas (22.32+/-34.00 x 10(6) cells vs 0.21+/-0.18 x 10(6)) (p<0.01). Nine of 32 (28%) lung transplant recipients with CF have died from pseudomonal allograft infections, but this is no greater than 4 of 21 (19%) deaths related to Pseudomonas infection in recipients without CF (p=0.34). CONCLUSIONS: Isolation of Pseudomonas from the lung allograft occurs more frequently and earlier after transplantation in recipients with CF. While infections related to Pseudomonas also occur more frequently in recipients with CF, there is no increase in mortality. There is an intense inflammatory response in the lung allograft associated with the isolation of Pseudomonas in recipients with and without CF.     

Gastro-oesophageal reflux: the disease of the millennium

Gastro-oesophageal reflux disease (GORD) is attributable primarily to acid and bile reflux through the lower oesophageal sphincter. Bile reflux has been implicated in severe oesophagitis, Barrett's oesophagus and oesophageal adenocarcinoma. Developments in evaluating and managing GORD and Barrett's are discussed, with their aetiological role in junctional gastro-oesophageal malignancies.     

Pulmonary aspergillosis in cystic fibrosis lung transplant recipients

STUDY OBJECTIVE: To define the prevalence of colonization and infection of the lower respiratory tract (LRT) with Aspergillus in lung transplant recipients with and without cystic fibrosis (CF). DESIGN: Retrospective review. SETTING: Large university lung transplant center. MATERIALS AND METHODS: The postoperative course of 31 CF and 53 non-CF double lung or double lobar transplant recipients receiving allografts from April 1991 to February 1996 was reviewed. All recipients were subjected to surveillance bronchoscopy and biopsy at predetermined intervals and when clinically indicated. BAL fluid (BALF) and biopsy material were examined by appropriate fungal culture and staining techniques. Infection was defined by the finding of tissue-invasive disease on biopsy specimens. RESULTS: Seven of the 31 CF recipients (22%) had Aspergillus isolated from cultures of sputum prior to transplantation. Following transplantation, 15 CF recipients (48%) had Aspergillus isolated from either sputum or BALF, including 4 of the 7 recipients identified with the fungus prior to transplantation. By contrast, 21 of the 53 non-CF recipients (40%) had Aspergillus isolated from the LRT following transplantation, none having had the fungus isolated prior to transplantation. The prevalence of Aspergillus did not differ between these groups (p = 0.51). Infections with Aspergillus occurred in 4 of the CF recipients (27%) and did not differ from the 3 infections (14%) identified in the non-CF recipients (p = 0.36). However, three of the four infections in the CF recipients involved the healing bronchial anastomosis and occurred prior to postoperative day 60. All three of these recipients had Aspergillus preoperatively. Postoperative infection was more common in the CF recipients having Aspergillus preoperatively than in those CF recipients without preoperative Aspergillus (p = 0.02). CONCLUSIONS: Isolation of Aspergillus from the LRT following double lung transplantation is common and generally not associated with tissue-invasive disease. Those CF recipients with Aspergillus isolated in cultures of sputum preoperatively are at risk for postoperative infections with this agent. The healing bronchial anastomosis is particularly vulnerable.     

Night blindness secondary to vitamin A deficiency in a patient with bile duct strictures after liver transplantation

We have studied the incidence of gastro-oesophageal reflux associated with the laryngeal mask airway (LMA) in 82 paralysed patients undergoing ventilation for elective orthopaedic surgery. Anaesthesia was managed by skilled LMA users. A pH-sensitive probe was passed nasally into the oesophagus before induction and recordings made during five phases of anaesthesia. Anaesthesia was induced with propofol and fentanyl and maintained with 0.5-1.5% isoflurane and nitrous oxide in oxygen. Neuromuscular block was produced with vecuronium and the train-of-four count maintained at < or = 1. Towards the end of surgery, neuromuscular function was allowed to recover spontaneously. All LMAs were inserted at the first attempt and ventilation was successful in all patients. There were no adverse airway events. Mean oesophageal pH values during each phase of anaesthesia were: before insertion 5.88 (SD 0.77), placement 5.85 (0.74), maintenance 5.89 (0.73), emergence 5.71 (0.78) and removal 5.82 (0.75). There were no reflux events (pH < 4.0) during any phase of anaesthesia. We conclude that the incidence of gastro-oesophageal reflux is low in paralysed patients undergoing ventilation for elective orthopaedic surgery when antagonism of neuromuscular block is avoided. The validity of these findings for unskilled LMA users is unknown.