PubMed Health⌕ Search

Biomedical subjects

Andrew Kramer

Publications and source records attributed to Andrew Kramer.

12 recordsLinked to original sources
PubMed2006

Is there a geriatrician in the house? Geriatric care approaches in hospitalist programs.

BACKGROUND: The rapid growth of the hospitalist movement presents an opportunity to reconsider paradigms of care for hospitalized older patients. METHODS: To determine the impact of the hospitalist movement on acute care geriatrics, we conducted a cross-sectional survey of the hospitalist community in 2003 and 2004. RESULTS: We identified innovations in geriatric hospital care in only 11 hospitalist programs. These innovations varied widely in complexity, goals, structure, and staffing. The majority targeted patients using age as a criterion and incorporated geriatrics training for nurses or physicians. Several innovations had one or more of the following features: geriatrician-hospitalists or gerontology nurse-practitioners, perioperative management for complex older patients, specialized geriatric services such as skilled nursing units or acute care for elders units, and quality improvement initiatives targeted to the older patient. A case study of the Hospital Internal Medicine group at the Mayo Clinic is presented as an example of a complex innovation highlighting several of these features. CONCLUSIONS: The scarcity of geriatric care approaches among hospitalist groups highlights the need for collaboration between hospitalists and geriatricians, with the goals of rethinking staffing models and organization of care and focusing on quality-improvement activities. In particular, perioperative care and postdischarge care are two clinical areas where innovation in hospital care may particularly benefit older patients. Significant opportunities remain for collaboration, coordination, and research to improve the care of acutely ill older patients at the intersection of geriatric and hospital medicine.

Cross-Sectional Studies↗
PubMed2006

A practical tool to identify patients who may benefit from a palliative approach: the CARING criteria.

Palliative care is often offered only late in the course of disease after curative measures have been exhausted. To provide timelier symptom management, advance care planning, and spiritual support, we propose a simple set of prognostic criteria that identifies persons near the end of life. In this retrospective cohort study of five prognostic indicators, the CARING criteria (Cancer, Admissions > or = 2, Residence in a nursing home, Intensive care unit admit with multiorgan failure, > or = 2 Noncancer hospice Guidelines), logistic regression modeling demonstrated high sensitivity and specificity for mortality at 1 year (c statistic > 0.8). A simple set of clinically relevant criteria applied at the time of hospital admission can identify seriously ill persons who have a high likelihood of death in 1 year and, therefore, may benefit the most from incorporating palliative measures into the plan of care.

Aged↗
PubMed2005

Tailoring cardiac resynchronization therapy using interventricular asynchrony. Validation of a simple model.

This study explores the use of interventricular asynchrony (interVA) for optimizing cardiac resynchronization therapy (CRT), an idea emerging from a simple pathway model of conduction in the ventricles. Measurements were performed in six dogs with chronic left bundle branch block (LBBB) and in 29 patients of the Pacing Therapies for Congestive Heart Failure (PATH-CHF)-I study. In the dogs, intraventricular asynchrony (intraVA) was determined using left ventricular (LV) endocardial activation maps. In dogs and patients, the maximum rate of rise of LV pressure (LV dP/dt(max)) and the pulse pressure (PP) and interVA [time delay between upslope of LV and right ventricular (RV) pressure curves] were measured during LV, RV, and biventricular (BiV) pacing with various atrioventricular (AV) delays. Measurements in the canine hearts supported the pathway model in that optimal resynchronization occurred at approximately 50% reduction of intraVA and at an interVA value halfway that during LBBB and LV pacing. In patients with significant hemodynamic response during pacing (n = 22), intrinsic interVA and interVA at peak improvement (interVA(p)) varied widely between patients (from -83 to -15 ms and from -42 to +31 ms, respectively). However, the model predicted individual interVA(p) accurately (SD of +/-6 ms and +/-12 ms for LV dP/dt(max) and PP, respectively). At equal interVA, LV and BiV pacing produced equal hemodynamic response, but in 11 of 22 responders, BiV pacing reduced interVA insufficiently to reach the maximum hemodynamic response. LV pacing at short AV delay proved to result in better hemodynamics than predicted by the model, indicating that additional factors determine hemodynamics during LV preexcitation. Guided by a simple pathway model, interVA measurements accurately predict optimal hemodynamic performance in individual CRT patients.

Animals↗
PubMed2005

Extended use of indwelling urinary catheters in postoperative hip fracture patients.

BACKGROUND: Indwelling urinary catheters are used postoperatively in hip fracture care. Their use beyond the immediate postoperative period may result in excess nosocomial infections. OBJECTIVES: The objectives of this study were to explore the relationship between extended indwelling urinary catheterization and outcomes for patients sustaining hip fracture discharged to skilled nursing facilities (SNFs), and to describe patient and hospital predictors of extended indwelling urinary catheterization. RESEARCH DESIGN: The authors conducted a retrospective cohort study. SUBJECTS: This study consisted of Medicare admissions to SNFs of patients discharged from a hospital with a primary diagnosis of hip fracture in 2001 (n=111,330). MEASURES: Dependent variables were the presence of urinary catheter at SNF admission and the patient-specific 30-day outcomes of rehospitalization for urinary tract infection, rehospitalization for sepsis, discharge to the community, and mortality. Independent variables were demographic, clinical, and hospital characteristics. RESULTS: Thirty-two percent of hip fracture discharges to SNFs had urinary catheters. These patients had greater odds of rehospitalization for urinary tract infection (adjusted odds ratio [AOR] 1.6, P<0.001) and death (AOR 1.3, P<0.001) at 30 days than patients without catheters after adjusting for patient characteristics such as age and comorbid conditions. Western region and urban location were associated with a higher likelihood of having an indwelling urinary catheter, whereas northern region and teaching hospital status were associated with a lower likelihood of having an indwelling urinary catheter. CONCLUSIONS: Extended use of indwelling urinary catheters postoperatively is associated with poor outcomes. The likelihood of having an indwelling urinary catheter at hospital discharge after hip fracture is associated with hospital characteristics in addition to patient characteristics. This practice variation deserves further study.

Aged↗
PubMed2005

Do-not-resuscitate and do-not-hospitalize directives of persons admitted to skilled nursing facilities under the Medicare benefit.

OBJECTIVES: To determine prevalence and factors associated with do-not-resuscitate (DNR) and do-not-hospitalize (DNH) directives of residents admitted under the Medicare benefit to a skilled nursing facility (SNF). To explore geographic variation in use of DNR and DNH orders. DESIGN: Retrospective cohort study. SETTING: Nursing homes in the United States. PARTICIPANTS: Medicare admissions to SNFs in 2001 (n=1,962,742). MEASUREMENTS: Logistic regression was used to select factors associated with DNR and DNH directives and state variation in their use. RESULTS: Thirty-two percent of residents had DNR directives, whereas less than 2% had DNH directives. Factors associated with having a DNR or DNH directive at the resident level included older age, cognitive impairment, functional dependence, and Caucasian ethnicity. African-American, Hispanic, Asian, and North American Native residents were all significantly less likely than Caucasian residents to have DNR (adjusted odds ratio (OR)=0.35, 0.51, 0.61, and 0.62, respectively) or DNH (adjusted OR=0.26, 0.41, 0.43, and 0.67, respectively) directives. In contrast, residents in rural and government facilities were more likely to have DNR or DNH directives. After controlling for resident and facility characteristics, significant variation between states existed in the use of DNR and DNH directives. CONCLUSION: Ethnic minorities are less likely to have DNR and DNH directives even after controlling for disease status, demographic, facility, and geographic characteristics. Wide variation in the likelihood of having DNR and DNH directives between states suggests a need for better-standardized methods for eliciting the care preferences of residents admitted to SNFs under the Medicare benefit.

Advance Directives↗
PubMed2004

Functional impact of rate irregularity in patients with heart failure and atrial fibrillation receiving cardiac resynchronization therapy.

AIMS: Atrial fibrillation (AFib) with a rapid ventricular response may adversely impact cardiac performance, especially in patients with heart failure. However, it remains uncertain whether rhythm irregularity per se has unfavourable effects apart from tachycardia, and whether rate regularization alone can improve heart function. METHODS AND RESULTS: Nine subjects with chronic AFib, atrioventricular nodal block, and symptomatic heart failure (ejection fraction 14-30%) were studied using a pressure-volume catheter. Ventricles were biventricularly paced (RV-apex, LV-lateral wall) at 80 or 120 min(-1) mean rate, using regular or irregular, Poisson-distributed stimulation. At 80 min(-1), ventricular function was similar between the two pacing modes. However, at 120 min(-1), irregular pacing impaired systolic (dP/dt(max): -8.2%, P<0.001) and diastolic function (dP/dt(min): +21%, P<0.001, LV end-diastolic pressure: +26%, P=0.007) compared with regular rate pacing. Contractile function during irregular pacing varied with the ratio of preceding/pre-preceding intercycle (RR) interval (dP/dt(max): 80 b.p.m.: r=0.69; 120 b.p.m.: r=0.74), whereas pre-load had little effect on instantaneous contractility. CONCLUSION: In heart failure subjects with AFib, RR-interval irregularity worsens cardiac function at elevated but not at normal range heart rate. Overall rate control is most important in these patients while rate regularization of rapid AFib may impart additional benefits.

Aged↗
PubMed2004

Short-term effects of right-left heart sequential cardiac resynchronization in patients with heart failure, chronic atrial fibrillation, and atrioventricular nodal block.

BACKGROUND: Single-site ventricular pacing in patients with heart failure, atrial fibrillation, and severe atrioventricular (AV) nodal block risks the generation of discoordinate contraction. Whether altering the site of stimulation can offset this detrimental effect and what role sequential right ventricular-left ventricular (RV-LV) stimulation might play in such patients remain unknown. METHODS AND RESULTS: Nine subjects with heart failure (ejection fraction, 14% to 30%), atrial fibrillation, and AV block were studied by pressure-volume analysis. Ventricular stimulation was applied to the RV (apex and outflow tract), LV free wall, and biventricular (BiV) at 80 and 120 bpm. BiV improved systolic function more than either site alone (dP/dt(max), 810+/-83, 924+/-98, 983+/-102 mm Hg/s for RV, LV, BiV, respectively; P<0.05), although LV pacing was significantly better than RV pacing. However, only BiV improved diastolic function (isovolumic relaxation) over RV or LV alone. Similar results were obtained for both heart rates. RV pacing site did not alter the BiV effect, and concomitant stimulation of both RV sites did not improve function over each alone. Finally, varying RV-LV delay revealed optimal responses with simultaneous pacing. CONCLUSIONS: Simultaneous BiV pacing acutely enhances both systolic and diastolic function over single-site RV or LV pacing in congestive heart failure patients with atrial fibrillation and advanced AV block. Sequential RV-LV stimulation offers minimal benefit on average and should perhaps be considered only in targeted subsets such as nonresponding patients.

Aged↗
PubMed2004

Predation resistance and nematocyst scaling for Metridium senile and M. farcimen.

Previous studies suggest that large body size reduces the risk of predation for acontiate sea anemones. For two species of Metridium, we found significant increases in the length of the acontial threads and in the mean lengths of the unfired acontial nematocyst capsules, with increasing body size. This supports the hypothesis that more damaging acontial defenses protect larger acontiate anemones from their predators. Metridium is planktivorous, and food size does not increase substantially with body size; so we expected smaller increases in nematocyst size for the feeding tentacles. In fact, scaling exponents were significantly smaller for the tentacle nematocysts than for acontial nematocysts of the same types in 3 out of 4 cases. This suggests that nematocyst scaling responds predictably to selection pressure. When specimens of the same size were compared, the non-clonal, subtidal species, M. farcimen, had significantly larger acontial nematocysts than did its clonal congener, M. senile, which lives at the upper tidal limits for major subtidal predators in the northeastern Pacific. Therefore, larger acontial nematocysts may be particularly advantageous where predation levels are high. These data demonstrate that closely related anemone species can be distinguished on the basis of ecologically and functionally relevant differences in nematocyst scaling.

Adaptation, Biological↗
PubMed2003

Clinical efficacy of cardiac resynchronization therapy using left ventricular pacing in heart failure patients stratified by severity of ventricular conduction delay.

OBJECTIVES: We assessed the clinical efficacy of single-site left ventricular (LV) pacing and determined the impact of baseline conduction delay severity on the magnitude of benefit. BACKGROUND: Multisite biventricular pacing can improve heart failure (HF) symptoms in patients with an intraventricular conduction delay by resynchronizing abnormal ventricular contractions and improving LV systolic function. METHODS: Eighty-six patients with at least New York Heart Association functional class II HF, chronic LV systolic dysfunction, normal sinus rhythm, and a QRS interval over 120 ms were implanted for atrial-synchronized LV pacing. The single-blinded, randomized, controlled, crossover study stratified patients 1:1 by the baseline QRS interval into long (QRS >150 ms) and short (QRS 120 to 150 ms) groups, which were compared during a three-month period of active (univentricular) pacing and a three-month period of inactive (ventricular inhibited) pacing. The primary end point was peak oxygen consumption (VO(2)) followed by anaerobic threshold, distance walked in 6 min, and quality-of-life questionnaire score. PATIENTS: Twelve patients were withdrawn before randomization and 17 could not complete both study periods. The short QRS group did not improve in any end point with active pacing. For the long QRS group, peak VO(2) increased 2.46 ml/min/kg (p < 0.001), the anaerobic threshold increased 1.55 ml/min/kg (p < 0.001), the distance walked in 6 min increased 47 m (p = 0.024), and the quality-of-life score improved 8.1 points (p = 0.004). CONCLUSIONS: Left ventricular pacing significantly improves exercise tolerance and quality of life in patients with chronic HF, LV systolic dysfunction, and a QRS interval over 150 ms.

Adolescent↗
PubMed2003

Biventricular mechanical asynchrony predicts hemodynamic effect of uni- and biventricular pacing.

We tested whether biventricular resynchronization explains contractile function changes with univentricular and biventricular pacing in heart failure patients with varying magnitudes of baseline biventricular asynchrony. Thirty patients (New York Hospital Association class > or = III, QRS duration > or =120 ms) were tested. Contractile function was measured by left ventricular maximum first derivative of pressure over time (dP/dtmax). Biventricular mechanical asynchrony was quantified by the normalized pressure-pressure (NPP) loop area formed by the cross-plot of right and left intraventricular pressure curves from each cardiac cycle. Any ventricular pacing increased dP/dtmax if it decreased baseline NPP loop area and almost always worsened dP/dtmax and asynchrony when baseline NPP loop area <0.3. The quantitative relationship between dP/dtmax and NPP loop area change depended on ventricular pacing site and timing relative to intrinsic activation. For similar NPP loop decreases, dP/dtmax increased 16% more with left and biventricular pacing compared with right ventricular pacing. In conclusion, right, left, or biventricular pacing can improve contractile function only in patients having sufficient baseline biventricular asynchrony. However, biventricular resynchronization is only one of the improvement mechanisms.

Aged↗