Research highlights – 22 July 2011

Research questions“Research highlights” is a weekly round-up of research papers appearing in the print BMJ. We start off with this week’s research questions, before providing more detail on some individual research papers and accompanying articles.

Pain control and agitation in dementia
Agitation is one of the most distressing neuropsychiatric symptoms associated with dementia, for both patients and carers. Its causes vary and can include pain. To test how much agitation may be a manifestation of untreated pain, Bettina Husebo and colleagues evaluated the effect of systematic use of painkillers in nursing home residents with moderate to severe dementia. They allocated individual nursing homes to standard care or to treatment for pain according to a stepwise protocol recommended by the American Geriatrics Society, with care staff trained in the assessment and treatment of pain. Agitation was significantly reduced in the intervention group compared, with an average reduction in scores for agitation of 17% compared with controls.

The obvious question is whether such a result is really due to pain relief or simply down to sedation, but the authors have answered this rather well: only a quarter of treated patients received sedative analgesics, while 70% received only high dose paracetamol, and the treatment and control groups did not differ significantly in activities of daily living or cognition.
As Paul Rosenberg and Constantine Lyketsos write in their linked editorial, the effects of the intervention “compare favourably with the equivocal results of treatment for agitation using antipsychotics, acetylcholinesterase inhibitors, and memantine.”

Tranexamic acid for intracranial haemorrhage
Last year, the CRASH-2 study showed that the antifibrinolytic tranexamic acid reduced blood loss in surgical patients and the risk of death in patients with traumatic bleeding, with no apparent increase in vascular occlusive events (Lancet 2010;376:23-32). However, earlier studies found that tranexamic acid increased the occurrence of cerebral ischaemia in patients with aneurysmal subarachnoid haemorrhage, which outweighed its benefits in preventing rebleeding.

The CRASH-2 collaborators therefore planned a randomised controlled trial nested within the CRASH-2 study to quantify the effect of an early short course of tranexamic acid on intracranial haemorrhage in patients who also had traumatic brain injury. Probably because of the small sample size, no results reached significance, leading to the authors’ conclusion that “neither moderate benefits nor moderate harmful effects can be excluded.”

However, as the authors and the accompanying editorial by Yvo Roos point out, all the results suggest beneficial effects of treatment, including no increase in cerebral ischaemia. They agree that this study’s findings justify a larger clinical trial to confirm the results, and re-evaluation of low dose, short term tranexamic acid in patients with other types of intracranial haemorrhage.

Beds for patients with mental illness
According to this ecological study by Patrick Keown and colleagues, the reduction in provision of beds for patients with mental illness since the 1980s has been closely associated with an increasing rate of involuntary admissions for mental illness in the English NHS. Accompanying the full length paper on is a podcast in which Keown says that the closure of two mental illness beds was associated with one additional involuntary admission in the following year. The link was particularly strong for civil admissions—that is, those in which the courts were not involved. He discusses the possible reasons for these observations and the implications for both patients and policy makers. There is little previous evidence for the effects of bed closures, so these findings—which support careful planning and slow implementation—are particularly timely in view of the proposed changes to the NHS. Listen to “Bed blues” at (13:20m).

Diet and risk of diverticular disease
In a prospective cohort study, Francesca Crowe and colleagues found that UK vegetarians had a lower risk of admission to hospital or death from diverticular disease than non-vegetarians. High intake of dietary fibre was also associated with reduced risks (doi:10.1136/bmj.d4131).

Sensitivity of computed tomography performed within six hours of onset of headache for diagnosis of subarachnoid haemorrhage
Jeffrey Perry and colleagues find that modern third generation computed tomography is extremely sensitive in identifying subarachnoid haemorrhage when done within six hours of headache onset and interpreted by a qualified radiologist (doi:10.1136/bmj.d4277).