Tuesday, December 14, 2010

Hospitals are Unsafe - There Are Still Plenty of Preventable Medical Errors

Over the past ten years and since the publication of the Institute of Medicine landmark book “To Err Is Human” there have been many attempts to reduce preventable medical errors which are estimated to take about 100,000 lives per year – perhaps many more. The question is whether all of this effort has had a substantial clinical impact.

The results of a recently published study are therefore concerning. A group lead by Dr Landrigan at Harvard evaluated the number of “harms” which occurred at ten randomly selected North Carolina hospitals. They taught a cadre of reviewers to use “triggers” in the medical record to prompt further analysis for an error that caused harm. The harms were categorized into five groups with E being temporary yet requiring an intervention through, F temporary but requiring initial or prolonged hospitalization, G permanent harm, H as life threatening harm and I causing or contributing to death. They then selected 10 records per quarter for the years 2002 through 2007 from each hospital, at random. The records were then reviewed in a random order by multiple internal and external trained reviewers, both nurses and doctors.

They found 588 harms among the 10,415 patient days or 57 harms/1000 days or 25 harms per 100 admissions. About 63% or 364 of the 588 harms were classified as preventable! These included 13 that caused permanent injury, 35 being life threatening and 9 contributing or leading to death.

Similar to prior studies, the harms occurred most frequently after procedures and medications. Most harms fell into categories E (144) and F (163).

It was disappointing to find that the rates of adverse events did not decline over the study time period. This, despite the fact that in North Carolina has an enviable record of a high level of engagement in patient safety programs and studies.

So there are still plenty of adverse events that occur in a hospital, they are most likely to be related to procedures or medications, most are preventable, and all too many are life threatening or lead to death.

This leads to the question of whether the many and various approaches that hospitals have embarked upon are actually doing what they need to do. It may be time for a reappraisal. Certainly a patient should have the expectation of not being harmed when in the hospital.

Wednesday, December 8, 2010

Two Treatments For Macular Degeneration – At Wildly Divergent Costs

Age-related macular degeneration (AMD) is the leading cause of blindness in the United States. More than 1 million Americans have neovascular or “wet” AMD and a slightly lower number have “dry” AMD which often progresses to the more severe “wet” form. Since this is a disease of aging, we can expect many more cases as the population expands in the coming years.

Neovascular AMD appears to be related, at lease in part, to excess production of vascular endothelial growth factor (VEGF-A.) A specially developed monoclonal antibody called ranibizumab is available and approved by the FDA for wet AMD. The monoclonal antibody binds to VEGF-A, blocking function and thereby allowing healing of the retina. As a result of decreased vessel growth and decreased leakage, vision can stabilize and frequently actually improve. (See the clinical therapeutics article by Folk and Stone in the New England Journal of Medicine 2010; 363:1648 - 1655 for more details.)

Ranibizumab is injected directly into the eye and an effective concentration lasts for about 30 days. Although not a trivial procedure, it is straight forward in experienced hands and takes but a few minutes in an outpatient setting under topical and local anesthesia. The procedure is repeated in four weeks and in four weeks again. If vision has stabilized or even improved, then the next visit is scheduled in five weeks, then six weeks, etc. It appears that most treatment failures relate to missed follow-ups so attention to timing is very critical.

There is another anti VEGF-A monoclonal antibody, called bevacizumab, approved by the FDA for use in metastatic colon cancer treatment. It costs about $75 for a 1.25 milligram dose whereas ranibizumab costs about $2000 for a comparable dose (0.5 mg.) Although clearly an “off label” use, many retinal specialists will offer bevacizumab as an alternative to ranibizumab and let the patients ultimately decide. Trials comparing the two drugs are underway with results expected in less than a year.

What is clear now is the intraocular injections of anti-VEGF-A monoclonal antibody has substantial efficacy with limited risk.

Wednesday, December 1, 2010

Replacing the Aortic Valve Without Open Surgery!

Aortic stenosis (a narrowing and hardening of the heart’s aortic valve) is not uncommon among older individuals. It begins without symptoms and progresses for years but, about 50% will die within 2 years once the fitst symptoms develop. The standard approach is to surgically replace the aortic valve which will improve both heart function and survival. Unfortunately, about 30% of symptomatic individuals cannot undergo surgery because of older age, other heart problems or other medical conditions that render surgery too risky.

A new approach is called transcatheter aortic value implantation (TAVI.) In this procedure, a catheter is inserted into the large femoral artery in the groin and run up to the heart. From the catheter, the patient’s valve is opened wide with an inflatable balloon. Then a bioprosthetic value made from bovine pericardium affixed to a stainless steel support frame is deployed into place via another balloon catheter and secured to patient’s own aortic valve base.

A randomized study of 358 patients with aortic stenosis not considered surgical candidates was completed comparing TAVI to standard therapy at 21 medical centers and reported in the New England Journal of Medicine on October 21, 2010. The results were clearly favorable. Standard therapy was noted to not alter the natural history of aortic stenosis with 51% dead in one year. TAVI was superior with improved cardiac symptoms and good hemodynamic performance of the new valve which persisted for at least the first year of follow-up and with 31% dying during that year, a substantial decline in mortality.

But there is never a “free lunch” and TAVI was associated with a 5% risk of serious stroke (compared to 1% in the control group) and multiple vascular complications, the latter apparently related to the requirement for a large catheter placed into the femoral artery. Further MRI studies of patients suggest that many have new perfusion defects of the brain after TAVI suggesting that emboli from the new valve may be rather common.

But all things considered the improvement in symptoms and the reduced death rate (it took only 5 patients treated with TAVI to avoid one death by 1 year) argue that TAVI is now the appropriate therapeutic approach for those with aortic stenosis who cannot otherwise undergo surgery. Hopefully, coming improvements in the device will lead to fewer complications.

The big question – will this become the approach of choice for those who otherwise are candidates for standard surgery for aortic valve replacement?

Praise for Dr Schimpff

The craft of science writing requires skills that are arguably the most underestimated and misunderstood in the media world. Dumbing down all too often gets mistaken for clarity. Showmanship frequently masks a poor presentation of scientific issues. Factoids are paraded in lieu of ideas. Answers are marketed at the expense of searching questions. By contrast, Steve Schimpff provides a fine combination of enlightenment and reading satisfaction. As a medical scientist he brings his readers encyclopedic knowledge of his subject. As a teacher and as a medical ambassador to other disciplines he's learned how to explain medical breakthroughs without unnecessary jargon. As an advisor to policymakers he's acquired the knack of cutting directly to the practical effects, showing how advances in medical science affect the big lifestyle and economic questions that concern us all. But Schimpff's greatest strength as a writer is that he's a physician through and through, caring above all for the person. His engaging conversational style, insights and fascinating treasury of cutting-edge information leave both lay readers and medical professionals turning his pages. In his hands the impact of new medical technologies and discoveries becomes an engrossing story about what lies ahead for us in the 21st century: as healthy people, as patients of all ages, as children, as parents, as taxpayers, as both consumers and providers of health services. There can be few greater stories than the adventure of what awaits our minds, bodies, budgets, lifespans and societies as new technologies change our world. Schimpff tells it with passion, vision, sweep, intelligence and an urgency that none of us can ignore.

-- N.J. Slabbert, science writer, co-author of Innovation, The Key to Prosperity: Technology & America's Role in the 21st Century Global Economy (with Aris Melissaratos, director of technology enterprise at the John Hopkins University).