HospitalistWeekly 2-27-08
Highlights
- Stroke conference examines differences in outcomes, symptoms
- Flu season worse than previous years, CDC reports
- Patients less likely to survive in-hospital cardiac arrest during off hours
- Treatments for acute renal failure may have similar outcomes
Stroke conference examines differences in outcomes, symptoms
.NEW ORLEANS—Treatment shortly after stroke onset, stroke outcomes according to time of ED presentation, symptoms that lead patients to present for care early, and gender differences in initial symptoms were the focus of studies presented at the American Heart Association's International Stroke Conference 2008 here last week. Study findings included:
- Tissue plasminogen activator (tPA) might be helpful in certain patients beyond the currently approved window of three hours after stroke onset. The phase II Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET) trial assigned 80 patients who showed on MRI potentially salvageable brain tissue, called perfusion-diffusion mismatch, to receive tPA (37 patients) or placebo saline solution (43 patients) between three and six hours after acute ischemic stroke onset. While not significant, there was a strong trend toward lower infarct growth in patients who received tPA, with 30% less infarct growth versus patients on placebo. The drug was also associated with significant restoration of blood flow at three to five days (56% on tPA vs. 26% on placebo, P= 0.01) and improved functional outcomes at 90 days. Results were too small to draw definitive conclusions, but provide support for more studies on extending the tPA treatment time window, researchers concluded. The study was published online February 22 in The Lancet Neurology.
- Labetalol and lisinopril significantly lowered blood pressure compared to placebo in hypertensive acute stroke, without causing serious adverse effects or an early increase in stroke severity. The phase II Control of Hypertension and Hypotension Immediately Post-Stroke (CHHIPS) pilot trial randomly assigned 179 patients who had had a stroke in the past 36 hours and hypertension to one of the two blood pressure medications individually, or to placebo. Patients received increasing doses for 14 days. Those who received active treatment had greater declines in systolic blood pressure in the first 24 hours than those on placebo, and after 14 days, treatment patients had significantly greater systolic blood pressure declines (31 mm Hg vs. 24 mm Hg for placebo). Active therapy with either labetalol or lisinopril reduced stroke mortality at 90 days, with the treatment group 2.2 times less likely to die, though mortality was not lower at two weeks. The results are important given that high blood pressure after stroke is common and is linked with poor outcomes, and indicate a phase III trial is warranted, the study’s researchers said.
- Stroke patients who come to the hospital at night and on weekends are more likely to die there than those treated in daytime hours and during the week. One study using data from 222,514 acute stroke admissions at 857 hospitals between 2003 and 2007 found that about 24% of hemorrhagic stroke patients who arrived in the emergency department between 7 a.m. and 6 p.m. on weekdays died, compared to 27% of hemorrhagic stroke patients who arrived at other times. About 5.2% of ischemic stroke patients died when they came to the hospital during business (weekday) hours, compared to 5.8% who arrived off-hours. Hemorrhagic stroke carries a greater burden for specialist care than ischemic stroke, and these specialists may be more difficult to reach on weekends, the study's lead investigator said. Another study of more than 2.4 million U.S. hospital admissions between 1988 and 2004 in which the primary diagnosis was stroke found that about 7.9% of all stroke patients admitted during the week died, compared to 10.1% admitted on weekends. For ischemic stroke patients in particular, mortality was 7.3% on weekdays versus 8.2% on weekends. The differences in outcome based on admission times persisted in both studies after researchers adjusted for age, race, gender and other factors, suggesting that the quality of care at hospitals differs during regular hours versus off hours. Some of these differences might be fixed if hospitals looked at their staffing and care practices during business hours and off hours, researchers said.
- Patients are most likely to present to the emergency department early for unilateral stroke symptoms and speech problems, while people with decreased consciousness are most likely to call 911. In a study that looked at patient charts for 1,922 stroke admissions from 15 Michigan hospitals, unilateral symptoms and speech difficulties were associated with early arrival, while visual disturbances and confusion were associated with later arrival. Earlier arrival was also associated with afternoon or evening onset of symptoms, onset at work, and history of heart disease. Other chief complaints associated with later arrival were difficulty with walking, balance and/or dizziness, and non-headache pain. In another study of medical records for 2,056 stroke and transient ischemic attack patients in the Cincinnati area, about 45% of the patients studied used emergency medical services. People who were older, had hemorrhagic stroke, and had a higher estimated stroke severity were more likely to call 911. After adjusting for these factors, researchers found those with confusion/decreased level of consciousness were 60% more likely to call, while those with weakness were 50% more likely to call. Those with numbness were 40% less likely to call, while speech/language difficulties and headache weren’t associated with EMS use. Both studies emphasize how important it is for public health messages to stress that people should seek care immediately for all stroke symptoms, the researchers concluded.
- Stroke presentation can differ by gender, according to an analysis of the medical records of 268 female and 181 male patients with first ischemic stroke in Rochester, Minn. during 1985 to 1989. Women were more likely to show symptoms of generalized weakness, fatigue, mental status changes and disorientation, while men more commonly complained of paresthesia, ataxia, visual disturbances and double vision. Ischemic stroke signs also differed by gender, with language disorder and fever more common in women and sensory abnormalities more common in men. Health professionals need to be aware of the differences in presentation by gender in order to increase the chance that stroke will be identified and treated promptly, researchers at the conference said.
—By Jessica Berthold, HospitalistWeekly senior writer
Flu season worse than previous years, CDC reports
.Influenza activity appears to be more intense this winter than it has been during the last several flu seasons, according to a new CDC report.
In the week ending Feb. 9, 49 states reported either widespread or regional flu activity, according to an early release from the CDC's Morbidity and Mortality Weekly Report. During the past three flu seasons (2004-2007), the number of states reporting such activity had peaked at 41 to 48 states. The percentage of specimens in the CDC’s surveillance areas that tested positive for influenza is also higher than it has been in recent years. The percentage for the week ending Feb. 9, 2008 was 33%, compared with 23% to 25% positive tests during the preceding three seasons. During the same week, 5.7% of outpatient visits to sentinel providers were for influenza-like illness, the CDC said.
The CDC is continuing to assess the degree of match between the circulating viruses and vaccine strains, but the agency still recommends vaccination with the trivalent influenza vaccine to provide at least partial protection and reduce the risk of complications and death. The agency also continues to recommend oseltamivir and zanamivir for treatment and prophylaxis of influenza, although some resistance to oseltamivir (5.9% of specimens tested) has been detected.
However, late last week, an FDA advisory panel recommended three new components to be included in next season's flu vaccine, according to the Feb. 22 Wall Street Journal. While it is hoped that a new vaccine would provide better protection, it may also cause production and shipping delays as manufacturers scramble to produce three new strains at the same time, said the article.
The CDC also announced last week that state health departments have made progress in emergency preparedness, but that some challenges remain. All state health departments can now receive urgent reports 24 hours a day, 7 days a week, while only 12 could in 1999. The states have also developed detailed emergency response plans, and the number of laboratories available to analyze samples has doubled.
Areas where further improvement is needed include the ability to quickly dispense medications or vaccines, the use of electronic health data, and implementation of public health mutual aid agreements that will enable sharing of supplies, equipment, personnel and information during emergencies, the CDC said.
The Morbidity and Mortality Weekly Report is online.
The Wall Street Journal is online (subscription required).
A press release on state preparedness is online.
Patients less likely to survive in-hospital cardiac arrest during off hours
.Hospitalized patients who have cardiac arrests are more likely to survive if the arrest happens on a weekday, instead of at night or on the weekend, a new study found.
Researchers compared 58,593 in-hospital cardiac arrests that occurred between 7 a.m. and 11 p.m. with 28,155 arrests that took place during night hours. The data came from 507 hospitals that participated in the National Registry of Cardiopulmonary Resuscitation between 2000 and 2007. The investigators also broke down the arrests between weekdays and weekends and then compared data on survival of the event, 24-hour survival, and survival to discharge, as well as favorable neurological outcomes.
The study found substantially lower rates of survival to discharge (14.7% vs. 19.8%), return of spontaneous circulation for longer than 20 minutes (44.7% vs. 51.1%), survival at 24 hours (28.9% vs. 35.4%), and favorable neurological outcomes (11.0% vs. 15.2%) for patients who arrested during the night. Among cardiac arrests that occurred during the day, survival rates were higher on weekdays than on weekends. The survival rates for cardiac arrests at night were similar throughout the week and about equal to those that occurred during the day on weekends.
The study authors noted that differences in day and night survival were not as large among monitored patients as among unmonitored patients, suggesting the monitoring or some other factor, such as intensive care staff, could improve outcomes. The research also found two areas of the hospital—the emergency department and trauma services—where survival rates did not differ by time of day. The authors noted that those services often have similar staffing at all times, unlike other areas of the hospital.
Based on the data, the study authors concluded that hospitals should focus on hospital-wide processes of care for resuscitation on nights and weekends and that such a focus could potentially improve patient safety and survival following cardiac arrest. The study was published in the Feb. 20 Journal of the American Medical Association.
The Journal of the American Medical Association is online.
Treatments for acute renal failure may have similar outcomes
.Intermittent hemodialysis and continuous renal replacement therapy (CRRT) yield similar clinical outcomes in patients with acute renal failure, according to a new study.
Canadian researchers analyzed existing research to determine the best way to manage dialysis in patients with acute renal failure. Of 173 articles that examined dialytic support in patients with acute renal failure and that reported mortality, length of hospital stay, hypotension and need for long-term dialysis, 30 randomized, controlled trials and 8 prospective cohort studies were eligible for review. The results appear in the Feb. 20 Journal of the American Medical Association.
The authors could draw no conclusions from the data regarding the best indications for or timing of renal replacement therapy. In addition, they found no significant clinical differences between CRRT and intermittent hemodialysis in all-cause mortality or need for long-term dialysis treatment (relative risk, 1.10 [95% CI, 0.99 to 1.23] and 0.91 [95% CI, 0.56 to 1.49], respectively). Patients receiving continuous venovenous hemofiltration had a lower risk for death at doses of 35 mL/kg per hour compared with 20 mL/kg per hour (relative risk, 0.74 [95% CI, 0.63 to 0.88]), while those receiving intermittent hemodialysis had a higher risk for death when cellulosic rather than biocompatible membranes were used (relative risk, 1.23 [95% CI, 1.01 to 1.50]).
Based on their research, the authors presented several suggestions for management of acute renal failure, including the following:
- Before deciding to start renal replacement therapy, physicians should assess intravascular volume, electrolyte and acid-base status, uremia, nutritional requirements and clinical course, among other variables, and should balance the potential benefit of earlier initiation of therapy against risk.
- Since this study found no clinical difference between CRRT and intermittent hemodialysis, the latter, less expensive method may be preferred for most patients.
- Clinicians may prefer CRRT in critically ill patients with severe hemodynamic instability. The target dose of CRRT, if used, should be 35 mL/kg per hour.
- Clinicians should not use unsubstituted cellulose membranes in patients with acute renal failure.
The authors stressed that these recommendations are based primarily on studies in critically ill patients and noted that few good-quality data are available to guide best practice, probably because a lack of consensus about the condition and indications for dialytic treatment, limited epidemiologic understanding and poor design and inadequate power of existing studies. Future studies, they wrote, should focus on defining subsets of patients with acute renal failure and on ways to improve outcomes after hospital discharge, and should have adequate power to evaluate clinically meaningful outcomes.
The Journal of the American Medical Association is online.
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