Parenteral nutrition

Over the last 50 years, parenteral nutrition has been recognised as an invaluable and potentially lifesaving tool in the physician's arsenal in the management of patients with intestinal failure or inaccessibility; however, it may also be associated with a number of potentially life-threatening complications. A recent NCEPOD report (2010) identified a number of inadequacies in the overall provision and management of parenteral nutrition and recommendations were made with the aim of improving clinical practice in the future. This paper focuses on the practical aspects relating to parenteral nutrition for adults, including important concepts, such as patient selection, as well as general management. We also explore the various pitfalls and potential complications and how these may be minimised.

Systematic review: does gastro-oesophageal reflux disease progress?

BACKGROUND

Gastro-oesophageal reflux disease affects approximately 20% of western populations. Barrett's oesophagus, associated with severe gastro-oesophageal reflux disease, is premalignant and regular endoscopic surveillance is generally performed. In contrast, mild gastro-oesophageal reflux disease is thought not to progress and is not generally subjected to endoscopic follow-up. Aim To investigate whether gastro-oesophageal reflux disease progresses endoscopically.

METHODS

Systematic review of the literature.

RESULTS

Well-designed prospective studies are few, diagnostic criteria were not always standardized, management strategies varied and various sources of bias could not be excluded. Whilst most patients do not progress to more severe forms of gastro-oesophageal reflux disease, and some cases actually regress, progression is seen in a small proportion of patients. Annual progression rates for non-erosive gastro-oesophageal reflux disease developing erosive oesophagitis ranged from 0% to 30%. About 1-22% of patients with mild erosive oesophagitis developed more severe inflammation annually, while 1-13% of patients with erosive oesophagitis developed Barrett's oesophagus each year.

CONCLUSION

Although most patients with gastro-oesophageal reflux disease do not progress, and some actually regress, progression does occur in a minority. Better data are required to determine whether patients with mild gastro-oesophageal reflux disease would benefit from increased surveillance with the aim of detecting more advanced disease.

Small intestinal transit, absorption, and permeability in patients with AIDS with and without diarrhoea

BACKGROUND

Diarrhoea in AIDS is associated with anorexia and weight loss. The importance of gastrointestinal transit in such symptoms has not been addressed.

AIMS

To assess jejunal to caecal transit times in subjects with AIDS related diarrhoea and weight loss and correlate these with measures of absorptive capacity and intestinal permeability.

METHODS

Jejunal to caecal transit times were assessed in 20 seronegative controls and 60 HIV seropositive subjects from serum analysis of 3-O-methyl-D-glucose and sulphapyridine after ingestion of the monosaccharide and sulphasalazine in aqueous solution. The method also allows an estimation of gastric emptying times for liquids. Intestinal absorptive capacity and permeability were assessed by a combined test using 3-O-methyl-D-glucose, D-xylose, L-rhamnose, and lactulose.

RESULTS

Gastric emptying was significantly delayed in all groups of patients with AIDS. Mean jejunal to caecal transit times were not significantly different between controls (246 (62) minutes) and patients without diarrhoea (AIDS, well: 278 (103) minutes; AIDS, wasting: 236 (68) minutes), cytomegalovirus colitis (289 (83) minutes), pathogen negative diarrhoea (192 (100) minutes), or microsporidiosis (190 (113) minutes), although 30% of patients had values below the control range. Patients with cryptosporidiosis differed significantly from controls (135 (35) minutes, p<0.0001), seven of 10 having rapid transit times. Absorptive capacity was reduced and intestinal permeability significantly increased in AIDS, but did not correlate significantly with transit times.

CONCLUSION

Small bowel transit is accelerated in many patients with AIDS, particularily in protozoal diarrhoea, but is not the sole explanation for malabsorption of monosaccharides.

Detection of herpesvirus DNA by nested polymerase chain reaction in cerebrospinal fluid of human immunodeficiency virus-infected persons with neurologic disease: a prospective evaluation

A nested polymerase chain reaction-based method was used prospectively to detect herpesvirus DNA in cerebrospinal fluid (CSF) from 111 patients with AIDS, 39 of whom had a suspected diagnosis of cytomegalovirus (CMV)-associated neurologic disease (patients with encephalopathy, polyradiculopathy, or peripheral neuropathy) and 72 who had alternative diagnoses. CSF from 24 (62%) of the patients with suspected CMV-associated disease had detectable CMV DNA compared with only 8 (11%) of the patients with other diagnoses. Varicella-zoster virus DNA was detected in CSF from 3 patients (2 with myelitis and 1 with encephalitis), all of whom had recent cutaneous zoster. No CSF specimen contained detectable herpes simplex virus type 1 DNA, and none of the patients with myelitis had detectable herpes simplex virus type 2 DNA in CSF. This study demonstrates a significant association between detectable CMV DNA in CSF and suspected CMV-associated neurologic disease in patients with AIDS.