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Biomedical subjects

T Kwiatkowski

Publications and source records attributed to T Kwiatkowski.

At least 19 recordsLinked to original sources
PubMed2006

Quality improvement in acute stroke: the New York State Stroke Center Designation Project.

BACKGROUND: Many hospitals lack the infrastructure required to treat patients with acute stroke. The Brain Attack Coalition (BAC) published guidelines for the establishment of primary stroke centers. OBJECTIVE: To determine if stroke center designation and selective triage of acute stroke patients improve quality of care. METHODS: Baseline chart abstraction was performed on all stroke patients admitted to 32 hospitals serving Brooklyn and Queens, NY, from March to May 2002. Hospitals were invited to meet BAC guideline-based criteria. Adherence was verified by on-site visits. After designation, acute stroke patients were selectively triaged. Remeasurement data were collected from August to October 2003. RESULTS: The authors abstracted 1,598 charts at baseline and 1,442 charts at remeasurement. From baseline to remeasurement, median times decreased for door to physician contact (25 vs 15 minutes, p = 0.001), CT performance for potential tissue plasminogen activator (t-PA) candidates (68 vs 32 minutes, p < 0.001), and t-PA administration (109 vs 98 minutes (p = NS). IV t-PA utilization increased from 2.4 to 5.2% (p < 0.005), select t-PA protocol violations decreased from 11.1 to 7.9% (p = NS), and the stroke unit admission rate increased from 16 to 39% (p < 0.001). In stroke centers (n = 14) vs nondesignated hospitals (n = 18), there were shorter median times from door to physician contact (10 vs 25 minutes, p < 0.001), CT performance for potential t-PA candidates (31 vs 40 minutes, p = NS), and t-PA administration (95 vs 115 minutes, p < 0.05). Stroke centers, compared with nondesignated centers, admitted acute stroke patients to stroke units more often (55.9 vs 10.9%, p < 0.001). CONCLUSIONS: Stroke center designation and selective triage of acute stroke patients improved the quality of care, including access to timely thrombolytic therapy and stroke units.

Aged↗
PubMed2001

Thrombolysis in patients with transient neurologic deficits.

What is the risk of thrombolysis in patients with acute stroke who might recover without treatment? In the National Institute of Neurological Disorders and Stroke rt-PA for Acute Stroke Trial, 2.6% of patients taking placebo showed spontaneous 24-hour recovery, compared to 11.5% of recombinant tissue-type plasminogen activator (rt-PA)-treated patients (p < 0.001). There were no symptomatic ICH in the patients taking placebo; one hypertensive, rt-PA-treated patient hemorrhaged. Assuming the National Institute of Neurological Disorders and Stroke protocol is followed rigorously, patients with acute stroke rarely recover spontaneously and the thrombolytic risk is low.

Aged↗
PubMed2001

A gene encoding a putative GTPase regulator is mutated in familial amyotrophic lateral sclerosis 2.

Amyotrophic lateral sclerosis 2 (ALS2) is an autosomal recessive form of juvenile ALS and has been mapped to human chromosome 2q33. Here we report the identification of two independent deletion mutations linked to ALS2 in the coding exons of the new gene ALS2. These deletion mutations result in frameshifts that generate premature stop codons. ALS2 is expressed in various tissues and cells, including neurons throughout the brain and spinal cord, and encodes a protein containing multiple domains that have homology to RanGEF as well as RhoGEF. Deletion mutations are predicted to cause a loss of protein function, providing strong evidence that ALS2 is the causative gene underlying this form of ALS.

Amino Acid Sequence↗
PubMed2000

Predicting prognosis after stroke: a placebo group analysis from the National Institute of Neurological Disorders and Stroke rt-PA Stroke Trial.

BACKGROUND: Physicians are often asked to predict outcome after acute stroke. Very little information is available that can reliably predict the likelihood of severe disability or death. OBJECTIVE: To develop a practical method for predicting a poor outcome after acute ischemic stroke. METHODS: Data from the placebo arms of Parts 1 and 2 of the National Institute of Neurological Disorders and Stroke rt-PA [recombinant tissue plasminogen activator] Stroke Trial were used to identify variables that could predict a poor outcome, defined as moderately severe disability, severe disability, or death (Modified Rankin Scale score >3) 3 months after stroke. RESULTS: Baseline variables that predicted poor outcome were the NIH Stroke Scale (NIHSS) >17 plus atrial fibrillation, yielding a positive predictive value (PPV) of 96% (95% CI, 88 to 100%). The best predictor at 24 hours was NIHSS >22, yielding a PPV of 98% (95% CI, 93 to 100%). The best predictor at 7 to 10 days was NIHSS >16, yielding a PPV of 92% (95% CI, 85 to 99%). CONCLUSIONS: Patients with a severe neurologic deficit after acute ischemic stroke, as measured by the NIHSS, have a poor prognosis. During the first week after acute ischemic stroke, it is possible to identify a subset of patients who are highly likely to have a poor outcome. These findings require confirmation in a separate study.

Aged↗
PubMed2000

Placebo treatment in acute stroke trials : benefit or harm to patients?

BACKGROUND AND PURPOSE: Some stroke patients and their families express reservations about participating in trials of experimental therapies for acute stroke. Among many reasons given for this is the concern that by participating, patients may be deprived of some component of routine care. We sought to determine the effect on outcome of participating in a clinical stroke trial while being treated with placebo. METHODS: Prospective clinical information was collected for all patients admitted with acute ischemic stroke between July 1995 and July 1996. A subgroup of these patients was enrolled in a clinical trial of acute stroke therapy and had been randomly assigned to the placebo group. The control group was selected from concurrent stroke patients who were not enrolled in any clinical trial. The National Institutes of Health Stroke Scale (NIHSS) was performed on admission and on day 7 after admission. The Glasgow Outcome Scale (GOS) was also performed at discharge. Stroke severity was classified as "severe" if NIHSS was >/=9 or GOS >/=3. Group comparisons were performed with chi(2) tests. RESULTS: One hundred twenty-six patients were evaluated. Forty-seven were placebo patients, and 79 were selected as control subjects. There were no significant differences between the groups with respect to age, sex, hematocrit, blood glucose level, history of hypertension, diabetes, smoking, or initial NIHSS. In addition, there was no difference between groups in terms of the frequency of baseline stroke subtype. Among our controls, 55 patients (70%) were on antithrombotic treatment during hospitalization, whereas none of our placebo patients were on any antithrombotic treatment. For the GOS at follow-up, a good outcome was attained by 76% of the control subjects and 72% of placebo patients (not significant). A severe NIHSS (>9) at follow-up, however, was documented in 15% of controls and 59% of placebo patients (P<0.001). There was a trend toward a higher ("worse") mean follow-up NIHSS among placebo patients (mean NIHSS, 11) versus controls (mean NIHSS, 6) (P=0.09). CONCLUSIONS: Patients enrolled in the placebo arms of some acute clinical stroke trials have similar functional outcomes but more severe neurological deficits at 1 week than did a control group. These findings might be partially explained by the withholding of antithrombotic medication and the exclusion criteria inherent in most trials. Vigilance is required to ensure that all patients participating in stroke studies be guaranteed optimal known medical therapy.

Aged↗
PubMed1999

Agreement and variability in the interpretation of early CT changes in stroke patients qualifying for intravenous rtPA therapy.

BACKGROUND AND PURPOSE: Ischemic changes identified on CT scans performed in the first few hours after stroke onset, which are thought to possibly represent early cytotoxic edema and development of irreversible injury, may have important implications for subsequent treatment. However, insecurity and conflicting data exist over the ability of clinicians to correctly recognize and interpret these changes. We performed a detailed review of selected baseline CT scans from the NINDS rt-PA Stroke Trial to test agreement among experienced stroke specialists and other physicians on the presence of early CT ischemic changes. METHODS: Seventy baseline CT scans from the NINDS Stroke Trial were read and classified for the presence or absence of various early findings of ischemia by 16 individuals, including NINDS trial investigators, other neurologists, other emergency medicine physicians, and radiology or stroke fellows. CT scans included normal scans and scans from patients who later developed symptomatic intracranial hemorrhage, as well as scans on which the NINDS rt-PA Stroke Trial neuroradiologist identified clear-cut early CT changes. For each CT finding, kappa-statistics were used to assess the proportion of agreement beyond chance. RESULTS: kappa-Values (95% confidence interval [CI]) ranged from 0.20 (-0.20, 0.61) (fair agreement) to 0.41 (0.37, 0.45) (moderate agreement) among the 16 viewers, and the kappa-value was only 0.39 (0.29, 0.49) (fair) in answer to the question "do early CT changes involve more than one third of the MCA [middle cerebral artery] territory?" There was substantial variability within each specialty group and between groups. kappa-Values were only fair to moderate even among physicians experienced in selecting and treating acute stroke patients with rtPA. Observed agreement ranged from 68% to 85%. Physicians agreed on the finding of early CT changes involving >33% of the MCA territory 77% of the time, although the kappa-value of 0.39 suggested only moderate agreement beyond chance. CONCLUSIONS: There is considerable lack of agreement, even among experienced clinicians, in recognizing and quantifying early CT changes. Improved methods of recognizing and quantifying early ischemic brain damage are needed.

Cerebrovascular Disorders↗
PubMed1999

Outcomes after laser stapedotomy with and without preservation of the stapedius tendon.

Our goal was to investigate the postoperative differences in hearing between patients who had their stapedius tendon sacrificed and those whose stapedius tendon was preserved during laser stapes surgery for otosclerosis. To that end, we performed a retrospective review by mailing extensive questionnaires to patients who had been operated on between 1994 and 1997. We also performed routine and special audiometric testing to augment the subjective data. Seventy-nine of 124 questionnaires (64%) were returned. Of the respondents, 75 patients had undergone additional pre- and/or postoperative audiometric testing, including tests to evaluate "hearing in noise" and to determine the "uncomfortable loudness level" (dynamic range). We found no statistically significant differences between the two groups with respect to their subjective responses and their audiologic test results. The responses to the questionnaire indicated that in most cases, hearing was improved by stapes surgery. We conclude that the stapedius tendon should be preserved whenever possible during stapes surgery, provided that it does not jeopardize the exposure or outcome.

Adult↗
PubMed1998

Early development of emergency medicine in Chennai (Madras), India.

India is the second most populous country in the world, with a population approaching 1 billion people. The development of emergency medicine is still in its earliest stages because the Medical Council of India (MCI) does not yet recogonize the specialty. Recent developments may cause the MCI to reconsider specialty status for emergency medicine as an academic discipline.

Delivery of Health Care↗
PubMed1998

Research fundamentals: II. Choosing and defining a research question.

This is the second in a series of articles developed by members of the SAEM Research Committee to describe a stepwise approach to the research process. This series is aimed at junior academic emergency physicians (EPs), as well as nonacademic EPs with an interest in the research process. This article describes the development of a testable research hypothesis. While a multitude of sources provide interesting questions for consideration, choosing and refining the research question, so that it can be tested adequately and answered completely, are difficult tasks.

Emergency Medicine↗
PubMed1998

Research fundamentals: III. elements of a research protocol for clinical trials.

A clinical trial is a powerful technique for evaluating the effectiveness of an experimental intervention. The initial stages of planning a clinical trial involve choosing and refining a research question, selecting a study design, and deciding on appropriate statistical tests and sample sizes. The success of the study depends upon how well these issues are thought out in advance, and how they can be put into practice. The protocol is the written document that allows the investigator to communicate details of how the research question will be answered. In the following article, the basic components of the research protocol are described. Issues related to quality control, data entry, and pilot testing are discussed. This is the third in a series of research fundamental concept papers, written by members of the SAEM Research Committee.

Clinical Protocols↗
PubMed1998

Hypertension and its treatment in the NINDS rt-PA Stroke Trial.

BACKGROUND AND PURPOSE: We examined the frequency, course, and treatment of hypertension in the NINDS rt-PA Stroke Trial. METHODS: Blood pressure (BP) was measured at the time of admission, at randomization, and then 36 times during the first 24 hours after randomization. Patients with a systolic BP of >185 mm Hg and a diastolic BP of >110 mm Hg at admission were defined as hypertensive before randomization, and those with a systolic BP of >180 mm Hg or a diastolic BP of >105 mm Hg within the first 24 hours after randomization were defined as hypertensive after randomization. Standardized clinical assessments were conducted at 24 hours and at 3 months. Post hoc analyses were conducted to evaluate the association of antihypertensive therapy with clinical outcomes. RESULTS: Of the 624 patients, 121(19%) had hypertension on admission and 372 (60%) had hypertension in the 24 hours after randomization. The use of antihypertensive therapy before randomization (tPA 9%, placebo 9%) and after randomization (tPA 24%, placebo 29%) was similar between placebo- and tPA-treated patients. No adverse effects of prerandomization antihypertensive therapy on 3-month favorable outcome were detected for either the placebo- or tPA-treated groups. For placebo patients with hypertension in the 24 hours after randomization, clinical outcome measures were similar for those patients who did and did not receive antihypertensive therapy after randomization (P > or = 0.26); antihypertensive therapy was not associated with declines in BP (P = 0.44) or with abrupt declines (P = 0.14). Those tPA patients who were hypertensive after randomization and received antihypertensive therapy were less likely to have a favorable outcome at 3 months (P < 0.01) than those who were hypertensive and did not receive antihypertensive therapy. CONCLUSIONS: The frequency of hypertension and the use of antihypertensive therapy were similar between the tPA and placebo groups in the NINDS rt-PA Stroke Trial. In the placebo group, antihypertensive therapy was not associated with less favorable outcomes at 3 months; postrandomization antihypertensive therapy was associated with less favorable outcomes for the tPA patients who were hypertensive. However, because of the nonrandomized use of antihypertensive therapy and the many post hoc comparisons leading to type 1 errors, the significance of this observation is unclear. Careful attention to BP and gentle management remain warranted for stroke patients treated with tPA.

Antihypertensive Agents↗
PubMed1997

Antibody protection to diphtheria in geriatric patients: need for ED compliance with immunization guidelines.

STUDY OBJECTIVE: Because 50% to 70% of geriatric patients have been shown to have nonproductive levels of tetanus antibodies, we postulated that this population might also have inadequate levels of diphtheria antibodies. Emergency physicians have the opportunity to immunize patients against tetanus and diphtheria. We sought to determine the seroprevalence of diphtheria antibodies in patients older than 65 years and to assess compliance with immunization guidelines in EDs. METHODS: Enzyme-linked immunosorbent assay for diphtheria antibodies was conducted in 58 outpatients of geriatric medical facility aged 65 years or older. We considered titers greater than .1 IU/mL protective. Eighteen ED personnel, ages 25 to 40 years, served as comparison subjects. The preparation used for immunization of injured patients--tetanus toxoid or tetanus and diphtheria toxoids adsorbed for adult use--was determined by means of a telephone survey of 64 New York City EDs. RESULTS: The mean age of our patients was 80 years (range, 65 to 95 years). Their mean diphtheria antibody titer was .17 IU/mL (range, .04 to .54 IU/mL). Thirty-three percent (19 of 58; 95% confidence interval [Cl], 21% to 54%) of patients had inadequate levels of diphtheria antibodies. We found no significant differences between protected and nonprotected patients with respect to age, sex, medical history, or military service. Patients with nonprotective levels of diphtheria antibodies were more likely to have inadequate tetanus antibody titers. Sixty-eight percent of patients without protection from diphtheria (13 of 19; 95% Cl, 48% to 88%) were also unprotected from tetanus, and 33% (13 of 39; 95% Cl, 19% to 47%) o those with adequate diphtheria antibodies had nonprotective levels of tetanus antibodies (P = .012). All 18 ED personnel had adequate diphtheria and tetanus antibodies. The telephone survey revealed that 30% (19 of 64) of EDs use only tetanus toxoid for immunization of injured patients. CONCLUSION: A significant percentage of geriatric patients have inadequate diphtheria antibodies. Emergency physicians must comply with immunization guidelines for injured patients to assure adequate protection from both tetanus and diphtheria.

Adult↗
PubMed1996

In vivo diode dosimetry for total marrow irradiation.

PURPOSE: To describe a method and evaluate the efficacy of using a p-type silicon diode as an alternative to thermoluminescent dosimeters for verifying the accuracy of total marrow irradiation setups and calculations. METHODS AND MATERIALS: A calibration factor has been measured for a 6 MV photon beam incident horizontally onto a polystyrene phantom inside an in-house built total marrow irradiation stand. Signal responses due to positioning and orientation of the diode with respect to the source were compared to a 0.6 cc cylindrical ionization chamber inside a polystyrene phantom. Procedures for predicting the diode reading and taking entrance measurements have been developed and action levels established to determine causes for discrepancies when ratios between predicted and actual values fell outside a +/- 5% tolerance range. Measurements were taken at the skin surface over the umbilicus calculation point for alternating 1.5 Gy anterior and posterior fractions given bidaily over a 3-day period. RESULTS: A total of 137 measurements taken from January to September 1994 for 23 patients were analyzed using a frequency histogram. The histogram indicated a mean reading of 1.002 +/- 2.6, and that three of the measurements fell outside the 5% tolerance. Investigation into the cause of the discrepancies showed that the diode had been improperly placed one time and that further patient immobilization needs to be considered. CONCLUSION: It is possible to use a diode as an in vivo dosimeter for a total marrow irradiation technique. The ease of implementation and immediate readouts make a diode system preferable to a thermoluminescent system for identifying systematic errors and verifying treatment configurations and monitor unit calculations.

Bone Marrow↗
PubMed1996

Seroprevalence of tetanus antibodies among adults older than 65 years.

STUDY OBJECTIVE: To define the extent of immunity against tetanus among patients older than 65 years of age by measuring antitetanus antibody levels. METHODS: A convenience sample of 129 patients from an urban comprehensive care geriatric center was studied. Serum was obtained and enzyme-linked immunosorbent assay (ELISA) testing performed. Twenty health care providers, aged 25 to 40 years, were tested for comparison. RESULTS: In 64 (50%) of 129 study patients, antitetanus antibody levels did not reach protective levels. Fifty-four (59%) of 92 women and 10 (27%) of 37 men did not have adequate titers. All 20 health care workers had protective titers. CONCLUSION: Elderly patients are substantially less likely than young individuals to have adequate immunity against tetanus. Emergency physicians must take this into consideration when evaluating tetanus immunization status in injured elderly patients.

Adult↗
PubMed1995

Time to equilibration of oxygen saturation using pulse oximetry.

OBJECTIVE: To determine the time it takes for O2 saturation measured by pulse oximetry to equilibrate after a change is made in supplemental O2 administered by nasal cannula in patients with cardiac and pulmonary disease. METHODS: A prospective, observational study of a convenience sample of 51 patients treated in a university-affiliated ED with nasal cannula O2. Patients were placed on and/or subsequently taken off O2 via nasal cannula set at 2 or 4 L/min based on clinical indications. Oxygen saturation was measured at 1-minute intervals over a 30-minute period using finger-probe pulse oximetry. Of the 51 patients in the study, 43 were monitored while O2 treatment was initiated and 18 were monitored when it was discontinued. RESULTS: Most (95%) of the patients placed on O2 attained equilibration of O2 saturation within 3.5 minutes. Most (95%) of the patients taken off supplemental O2 attained equilibration of O2 saturation within 4.5 minutes. CONCLUSION: The interval to equilibration of O2 saturation in patients receiving O2 by nasal cannula is considerably shorter than the 20-30 minutes generally suggested. Adequacy of O2 supplementation should be assessable much sooner than was previously taught.

Adult↗