Intended for healthcare professionals

Short Cuts

All you need to read in the other general journals

BMJ 2009; 338 doi: https://doi.org/10.1136/bmj.b526 (Published 10 February 2009) Cite this as: BMJ 2009;338:b526

People with acute low back pain do not need lumbar imaging

Patients with uncomplicated acute or subacute low back pain do not need lumbar imaging, according to a meta-analysis of six randomised trials. Care that includes imaging such as radiographs, computed tomography, or magnetic resonance imaging doesn’t reduce pain, improve function, or affect quality of life.

The trials compared care with and without immediate imaging for people with short term back pain and no symptoms suggesting serious pathology, such as infections, cancer, or cauda equina syndrome. The authors judged five of the six trials to be of reasonably high quality. They found that immediate imaging had no significant effect on any outcome measured between three weeks and one year after the back pain began. The findings were most convincing for primary care patients in trials testing lumbar radiography. Doctors should resist pressure from patients and follow international guidelines that already recommend against imaging, say the authors. It is ineffective, costly, and exposes people to unnecessary radiation or even unnecessary invasive treatments.

A linked editorial endorses this view and suggests educating the public both inside and outside general practitioners’ surgeries (p 436). Some evidence exists that shifting patients’ views can have a durable effect on the way doctors manage acute back pain.

Screening identifies more cases of urinary tract stones in Chinese infants

In September last year the Chinese authorities discovered that many popular brands of infant formula milk were contaminated with the nitrogenous chemical melamine, after an unexpected number of babies and small children developed urinary tract stones. During the ensuing free screening programme, 589 infants under 3 years were screened with ultrasonography at one academic hospital in Beijing. Fifty of them had urinary tract stones (8.5%); 421 had received contaminated formula milk. Infants who were exposed to high amounts of the contaminant were five to seven times more likely to have stones than were unexposed infants. The stones were largely asymptomatic, were not associated with renal dysfunction, and most would have been missed by routine urinalysis, say the researchers.

Similar results were reported from a screening programme in Taipei, Taiwan (doi:10.1056/NEJMc0810070), where researchers found renal tract stones in nine of 44 children given heavily contaminated formula milk. Again, exposure to melamine was statistically associated with stones that were asymptomatic and would have been missed by urinalysis alone. A third study, from Hong Kong (doi:10.1056/NEJMc0809955), reported just one case of urinary tract stones in more than 2000 children screened. The authors don’t say how many of them received contaminated formula.

New sedative looks promising for prolonged sedation in intensive care

Dexmedetomidine is a relatively new intravenous sedative, currently licensed for short term use only. A large trial now indicates that it is safe and effective for up to 30 days as a sedative for patients on intensive care units. The new drug was as good as midazolam at sedating patients to a carefully controlled target (on target 77.3% of the time v 75.1% for midazolam) and was associated with significantly less delirium (prevalence 54% (132/244) v 76.6% (93/122); P=0.001). Patients given dexmedetomidine were extubated more quickly and they had fewer infections, fewer episodes of hypertension, and a lower incidence of tachycardia than those given midazolam. But the newer drug was associated with a significantly higher risk of bradycardia (42.2% (103/244) v 18.9% (23/122); P=0.001). The trial was double blind, multicentre, and paid for by the manufacturers of dexmedetomidine. Mortality was essentially the same in both groups.

A linked editorial (p 542) says that these results widen the range of sedatives suitable for critically ill patients. Dexmedetomidine looks reasonably safe at higher doses and for longer periods than was previously thought. A lower risk of delirium is an important advantage for patients and could be related to the newer drug’s unique mechanism of action. Dexmedetomidine binds to α2 adrenoceptors, whereas benzodiazepines and the other established sedative, propofol, both act on γ amino butyric acid receptors.

Respiratory syncytial virus is an important seasonal pathogen in the US

Researchers recently estimated that respiratory syncytial virus (RSV) infections account for one in 13 visits to primary care doctors, one in 38 visits to emergency departments, and one in 334 hospital admissions in children under 5 in the US. Public health authorities are unaware of the burden of disease caused by this seasonal virus, because only a minority of children are given a specific diagnosis, say the researchers. Bronchiolitis, pneumonia, and upper respiratory tract infection were all common diagnoses given to infected children in their community based study.

Public health authorities may also be unaware that the morbidity associated with RSV extends well beyond infancy and affects predominantly healthy children over the age of 1, they warn. Most children with confirmed RSV infection in this study had no predisposing factors such as prematurity (66% of the 564 inpatients and 73% of the 355 treated as outpatients).

These data come from a surveillance network of hospitals, paediatric offices, and emergency departments in Nashville, Rochester (New York), and Cincinnati. As part of winter surveillance between 2000 and 2004, researchers took nose and throat swabs from 5067 children with respiratory symptoms such as fever, cough, sore throat, and wheezing. Nearly a fifth had RSV (18%; 919/5067)—mostly RSV group A.

Risk of breast cancer falls as women stop taking HRT

The incidence of breast cancer in postmenopausal women has been falling since around 2002 in the US, probably because so many women have given up hormone replacement therapy (HRT), say researchers. Follow-up data from two key studies in the Women’s Health Initiative (WHI) show a clear decrease in incidence after women in the studies stopped taking their combined hormone replacement therapy. Women in the placebo controlled trial (n=15 387) were told to stop all study drugs in 2002, after early results showed greater harm than benefit. Women in the observational study (n=41 449) also reduced their use of hormones substantially, after publicity surrounding the WHI and other trials. Both studies in the WHI had found an increase in the risk of breast cancer associated with use of combined hormone replacement therapy. This risk fell rapidly once women stopped taking it. They were followed up until 2005.

These authors are fairly confident that the falling breast cancer trend in these women was caused by a similar trend in use of hormone replacement therapy, not by some other factor such as changes in rates of mammography. The speed of the effect suggests that preclinical cancers regress when women stop taking hormone replacement therapy.

A standardised discharge strategy helped prevent readmissions

Many patients end up back in hospital only months after discharge. Suspecting that chaotic discharge procedures were partly to blame, researchers from one academic hospital in the US designed a comprehensive package of information, teaching, and support to help keep discharged patients away from hospital. Dedicated nurses wrote discharge plans; sorted out drugs; contacted primary care providers; and took patients through their diagnosis, test results, and post discharge appointments. Pharmacists called patients shortly after discharge to check they understood what they were meant to be taking and when.

A randomised trial showed that the systematic strategy worked. One month after discharge, 61 of the 370 patients who received it had visited an emergency department compared with 90 of 368 controls (P=0.014). Readmissions to hospital were also significantly less likely in patients given the “re-engineered discharge” (55/370 v 76/368). They were more likely than controls to know and understand their diagnosis, to know the name of their primary care doctor, to visit him or her for follow-up, and to understand their medication.

The intervention worked well in this large urban hospital and should be tested in other settings, say the authors. It might even save money. Preliminary costing suggested a saving of about $400 (£275; €312) per patient, excluding the cost of the intervention.

Early trial reports success with intensive insulin therapy for critically ill children

Hyperglycaemia is common in critically ill children, and specialists continue to debate how aggressively to treat it. A new trial from one paediatric intensive care unit in Belgium reports clear benefits associated with an intensive regimen of insulin designed to maintain normoglycaemia in children (3.9-5.6 mmol/l) and infants (2.8-4.4 mmol/l). The 349 children treated intensively were discharged sooner from the unit than controls given insulin as needed for hyperglycaemia (5.51 v 6.15 days; P=0.017)). They also had an attenuated inflammatory response, fewer secondary infections, and even a significantly reduced risk of death on the intensive care unit (2.6% (9/349) v 5.7% (20/351); P=0.038). As expected, the intensive regimen was associated with substantially more episodes of hypoglycaemia (24.9% (87/349) v 1.4% (5/351); P<0.0001). The long term consequences of these episodes are unknown, and the authors are planning long term follow-up to find out.

The benefits look convincing, but the authors and a linked comment agree that they must be confirmed before doctors change their current practice (doi:10.1016/S0140-6736(09)60045-3). This unit has extensive experience in tight glucose control, and results may not be so favourable in less confident hands. Three quarters of the children in this trial were recovering from cardiac surgery, which limits generalisability to other populations.

Notes

Cite this as: BMJ 2009;338:b526