Atrial fibrillation in patients with cryptogenic stroke

BACKGROUND

Atrial fibrillation is a leading preventable cause of recurrent stroke for which early detection and treatment are critical. However, paroxysmal atrial fibrillation is often asymptomatic and likely to go undetected and untreated in the routine care of patients with ischemic stroke or transient ischemic attack (TIA).

METHODS

We randomly assigned 572 patients 55 years of age or older, without known atrial fibrillation, who had had a cryptogenic ischemic stroke or TIA within the previous 6 months (cause undetermined after standard tests, including 24-hour electrocardiography [ECG]), to undergo additional noninvasive ambulatory ECG monitoring with either a 30-day event-triggered recorder (intervention group) or a conventional 24-hour monitor (control group). The primary outcome was newly detected atrial fibrillation lasting 30 seconds or longer within 90 days after randomization. Secondary outcomes included episodes of atrial fibrillation lasting 2.5 minutes or longer and anticoagulation status at 90 days.

RESULTS

Atrial fibrillation lasting 30 seconds or longer was detected in 45 of 280 patients (16.1%) in the intervention group, as compared with 9 of 277 (3.2%) in the control group (absolute difference, 12.9 percentage points; 95% confidence interval [CI], 8.0 to 17.6; P<0.001; number needed to screen, 8). Atrial fibrillation lasting 2.5 minutes or longer was present in 28 of 284 patients (9.9%) in the intervention group, as compared with 7 of 277 (2.5%) in the control group (absolute difference, 7.4 percentage points; 95% CI, 3.4 to 11.3; P<0.001). By 90 days, oral anticoagulant therapy had been prescribed for more patients in the intervention group than in the control group (52 of 280 patients [18.6%] vs. 31 of 279 [11.1%]; absolute difference, 7.5 percentage points; 95% CI, 1.6 to 13.3; P=0.01).

CONCLUSIONS

Among patients with a recent cryptogenic stroke or TIA who were 55 years of age or older, paroxysmal atrial fibrillation was common. Noninvasive ambulatory ECG monitoring for a target of 30 days significantly improved the detection of atrial fibrillation by a factor of more than five and nearly doubled the rate of anticoagulant treatment, as compared with the standard practice of short-duration ECG monitoring. (Funded by the Canadian Stroke Network and others; EMBRACE ClinicalTrials.gov number, NCT00846924.).

Risk adjustment measures and outcome measures for prehospital trauma research: recommendations from the emergency medical services outcomes project (EMSOP)

OBJECTIVES

The objectives were to conduct a comprehensive, systematic review of the literature for risk adjustment measures (RAMs) and outcome measures (OMs) for prehospital trauma research and to use a structured expert panel process to recommend measures for use in future emergency medical services (EMS) trauma outcomes research.

METHODS

A systematic literature search and review was performed identifying the published studies evaluating RAMs and OMs for prehospital injury research. An explicit structured review of all articles pertaining to each measure was conducted using the previously established methodology developed by the Canadian Physiotherapy Association ("Physical Rehabilitation Outcome Measures").

RESULTS

Among the 4,885 articles reviewed, 96 RAMs and/or OMs were identified from the existing literature (January 1958 to February 2010). Only one measure, the Glasgow Coma Scale (GCS), currently meets Level 1 quality of evidence status and a Category 1 (strong) recommendation for use in EMS trauma research. Twelve RAMs or OMs received Category 2 status (promising, but not sufficient current evidence to strongly recommend), including the motor component of GCS, simplified motor score (SMS), the simplified verbal score (SVS), the revised trauma score (RTS), the prehospital index (PHI), EMS provider judgment, the revised trauma index (RTI), the rapid acute physiology score (RAPS), the rapid emergency medicine score (REMS), the field trauma triage (FTT), the pediatric triage rule, and the out-of-hospital decision rule for pediatrics.

CONCLUSIONS

Using a previously published process, a structured literature review, and consensus expert panel opinion, only the GCS can currently be firmly recommended as a specific RAM or OM for prehospital trauma research (along with core measures that have already been established and published). This effort highlights the paucity of reliable, validated RAMs and OMs currently available for outcomes research in the prehospital setting and hopefully will encourage additional, methodologically sound evaluations of the promising, Category 2 RAMs and OMs, as well as the development of new measures.

Occupational asthma and allergy in snow crab processing in Newfoundland and Labrador

BACKGROUND

Risk factors and prevalence of occupational asthma (OA) and occupational allergy (OAl) in the snow crab-processing industry have been poorly studied.

OBJECTIVE

To estimate the prevalence of OA and OAl in snow crab-processing workers and determine their relationship with exposure to snow crab allergens and other potential risk factors.

METHODS

A total of 215 workers (120 female/95 male) were recruited from four plants in Newfoundland and Labrador, Canada in 2001-2002. Results from questionnaires, skin-prick tests to snow crab meat and cooking water, specific IgEs against the latter, spirometry and peak flow monitoring were used to develop a diagnostic algorithm. An index based on work history and exposure measurements of snow crab aeroallergens was developed to estimate the cumulative exposure for each worker.

RESULTS

The prevalences of almost certain or highly probable OA and OAl were 15.8% and 14.9%, respectively. A high cumulative exposure to crab allergens, in jobs mostly held by women, was associated with OA (odds ratio (OR) = 14.0, 95% CI 3.0 to 65.8) (highest vs lowest Cumulative Exposure Index) and with OAl (OR = 7.1, 95% CI 1.9 to 29.0); job held when symptoms started (cleaning, packing, freezing) also predicted OA (OR = 3.9, 95% CI 1.6 to 8.7) and OAl (OR = 3.2, 95% CI 1.4 to 7.5). Atopy (OR = 2.8, 95% CI 1.2 to 6.8), female gender (OR = 10.7, 95% CI 3.6 to 32.1) and smoking were significant determinants for OA (OR = 3.1, 95% CI 1.3 to 7.4).

CONCLUSIONS

The prevalences of OA and OAl are high in snow crab-processing workers of Canada's East Coast. Cumulative exposure to snow crab allergens was related to the prevalences of OA and OAl in a dose-response manner taking into account atopy, gender and smoking.

Promoting evidence based medicine in preclinical medical students via a federated literature search tool

BACKGROUND

Medical educators are increasingly faced with directives to teach Evidence Based Medicine (EBM) skills. Because of its nature, integrating fundamental EBM educational content is a challenge in the preclinical years.

AIMS

To analyse preclinical medical student user satisfaction and feedback regarding a clinical EBM search strategy.

METHODS

The authors introduced a custom EBM search option with a self-contained education structure to first-year medical students. The implementation took advantage of a major curricular change towards case-based instruction. Medical student views and experiences were studied regarding the tool's convenience, problems and the degree to which they used it to answer questions raised by case-based instruction.

RESULTS

Surveys were completed by 70% of the available first-year students. Student satisfaction and experiences were strongly positive towards the EBM strategy, especially of the tool's convenience and utility for answering issues raised during case-based learning sessions. About 90% of the students responded that the tool was easy to use, productive and accessed for half or more of their search needs.

CONCLUSIONS

This study provides evidence that the integration of an educational EBM search tool can be positively received by preclinical medical students.

In-patient treatment of chronic daily headache using dihydroergotamine: a long-term follow-up study

BACKGROUND

The treatment of chronic daily headache (CDH) due to medication overuse remains a common and difficult problem. For selected patients refractory to outpatient management we have used a treatment protocol using dihydroergotamine (DHE) as introduced by Raskin, during a brief (typically 48 hours) in-patient stay. While many studies have documented the short-term efficacy of the DHE protocol, there are limited data on its long-term effects. The purpose of this study was to evaluate quality of life, at three months post treatment and the present time.

METHODS

A retrospective chart review of all patients admitted for the DHE protocol from 1991 to 1996 revealed 174 cases. Of these, 132 patients were interviewed by phone.

RESULTS

The DHE protocol was shown to decrease headache frequency, severity, headache medication use, and absences from work both at three months and the time of interview.

CONCLUSION

This study has the largest patient base and the longest follow-up period for the use of DHE for CDH. The results confirm that the DHE protocol is helpful in breaking the cycle of CDH, although the long-term outcomes of this study are more conservative than other studies have reported.

Radiation absorbed dose estimates for oxygen-15 radiopharmaceuticals (H2(15)O, C15O, O15O) in newborn infants

In preparation for measurement of regional cerebral oxygen metabolism by positron emission tomography, radiation absorbed dose estimates for 19 internal organs, blood, and total body were calculated for newborn infants following bolus intravenous administration of H2(15)O and brief inhalation of C15O and O15O. Cumulated activity for each radiopharmaceutical was calculated from a compartmental model based on the known biologic behavior of the compound. Values for mean absorbed dose/unit cumulated activity (S) for internal organs and total body were based on a newborn phantom. S was separately calculated for blood. Total radiopharmaceutical absorbed dose estimates necessary to measure cerebral oxygen metabolism in a 3.51-kg infant based on 0.7 mCi/kg H2(15)O and 1 mCi/kg C15O and O15O were determined to be 1.6 rad to the lung (maximum organ dose), 0.28 rad to the marrow, 0.46 rad to the gonads, and 0.22 rad to total body. These values are similar to those for current clinical nuclear medicine procedures employing 99mTc in newborn infants.