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Biomedical subjects

J D Loeser

Publications and source records attributed to J D Loeser.

At least 19 recordsLinked to original sources
PubMed1999

Pain: an overview.

Until the 1960s, pain was considered an inevitable sensory response to tissue damage. There was little room for the affective dimension of this ubiquitous experience, and none whatsoever for the effects of genetic differences, past experience, anxiety, or expectation. In recent years, great advances have been made in our understanding of the mechanisms that underlie pain and in the treatment of people who complain of pain. The roles of factors outside the patient's body have also been clarified. Pain is probably the most common symptomatic reason to seek medical consultation. All of us have headaches, burns, cuts, and other pains at some time during childhood and adult life. Individuals who undergo surgery are almost certain to have postoperative pain. Ageing is also associated with an increased likelihood of chronic pain. Health-care expenditures for chronic pain are enormous, rivalled only by the costs of wage replacement and welfare programmes for those who do not work because of pain. Despite improved knowledge of underlying mechanisms and better treatments, many people who have chronic pain receive inadequate care.

Acute Disease↗
PubMed1999

Resolution of central pain after embolization of an arteriovenous malformation. Case report.

The authors describe a patient with right-sided central pain resulting from a left parietal arteriovenous malformation (AVM). The AVM was treated with staged embolization and stereotactic radiosurgery, and its obliteration was documented on follow-up angiographic studies. Surprisingly, the patient noted complete resolution of her pain syndrome after embolization, which is an extremely rare result. Central pain and its proposed mechanisms are discussed.

Angiography, Digital Subtraction↗
PubMed1998

5-year reoperation rates after different types of lumbar spine surgery.

STUDY DESIGN: Population-based cohort study of Washington State patients who underwent lumbar spine surgery for degenerative conditions in 1988. OBJECTIVES: To compare complications and reoperation rates during the 5-year period after surgery between patients who have undergone lumbar spine fusion surgery and those who have undergone laminectomy or discectomy alone. SUMMARY OF BACKGROUND DATA: Spinal fusion is associated with wider surgical exposure, more extensive dissection, and longer operative times than lumbar surgery without fusion, and previous studies have shown higher complication rates and hospital charges associated with these more complex procedures. In elderly patients, spinal fusion operations were associated with higher mortality rates than laminectomy or discectomy alone, and reoperation rates were not lower. In the current study, reoperations, mortality, and complications following lumbar spine surgery were examined for the general population. METHODS: A statewide hospital discharge database was used to identify all Washington patients who underwent spine surgery in 1988 and to determine the rate of reoperation during the subsequent 5 years. Administrative records also were used to identify complications, mortality, and hospital charges associated with the operations. Unadjusted complication and reoperation rates for the groups were compared using chi-square statistics. Adjusted rates were compared using logistic regression and proportional hazards (Cox) regression after controlling for age, gender, prior spine surgery, diagnosis, comorbidity, type of surgery, and coverage by Workers' Compensation. RESULTS: Of 6376 patients who underwent lumbar surgery for degenerative conditions in Washington in 1988, 1041 (16%) had operations involving spine fusion. Diagnoses of degenerative disc disease or possible instability were more frequent among patients undergoing fusion surgery, whereas herniated discs were more frequent among those undergoing discectomy or laminectomy alone. Complications were recorded in 18% of fusion patients and 7% of nonfusion patients (P < 0.01), but mortality rates did not differ. Unadjusted reoperation rates over the 5-year period were greater for patients who underwent fusion than for patients who underwent nonfusion surgery (18% vs. 15%, respectively), but after adjustment for baseline characteristics, fusion patients had only a slightly greater (and nonsignificant) risk of reoperation (relative risk 1.1, confidence interval .9-1.3). CONCLUSION: As in previous studies, complications in the current study occurred more frequently among patients who underwent lumbar spine fusion than among those who underwent laminectomy or discectomy alone. Reoperations were at least as frequent after fusion, but the authors could not assess treatment efficacy in terms of pain relief or improved function. Although the characteristics of patients undergoing fusion differed from those undergoing a laminectomy or discectomy alone, there appeared to be sufficient overlap in the clinical populations to warrant closer scrutiny of the safety, efficacy, and indications for spinal fusions, preferably in randomized trials.

Adult↗
PubMed1998

Percutaneous placement of ventriculoatrial shunts in the pediatric population.

The percutaneous placement of ventriculoatrial (VA) shunts has been previously described, usually in adults. We report a series of 7 pediatric cases ranging from 6 to 17 years. Five patients were female and 2 were male. All patients had prior ventriculoperitoneal (VP) shunts for hydrocephalus, of which 1 had been subsequently converted to a ventriculopleural shunt. Indications for conversion to a VA shunt were intra-abdominal infection in 6 cases and chronic pleuritic chest pain in 1 patient. The venous entry was the subclavian vein in all cases. All patients have remained asymptomatic since the operation. There were no complications associated with the procedures, with follow-up ranging from 2 to 12 months. This technique is a viable alternative to the open cervical approach for venous entry to the right atrium in the pediatric population.

Adolescent↗
PubMed1997

Acquired hydrocephalus associated with superior vena cava syndrome in infants.

We report observations on children with the unusual combination of superior vena cava syndrome in infancy followed by communicating hydrocephalus. Following retrospective review of hospital discharges at a tertiary children's hospital, three children were identified in a 13-year period. Two term infants were treated with extracorporeal membrane oxygenation for pulmonary failure associated with congenital diaphragmatic hernia. These infants had septic complications of central venous lines. A post-term infant required reconstruction of the superior vena cava following cannulation for cardiac bypass surgery to repair transposition of the great vessels. Thrombosis occurred and was followed by the sequential development of superior vena cava syndrome and communicating hydrocephalus. The findings in these patients suggest that communicating hydrocephalus may be caused by superior vena cava syndrome. This is an unusual complication of therapeutic manipulation of the heart and great veins. Cerebrospinal fluid shunting may be required.

Extracorporeal Membrane Oxygenation↗
PubMed1997

Doctors, diagnosis, and disability: a disastrous diversion.

Patients and third party payers expect physicians to identify damage or disease as the cause of pain and disability, but often there is no damage or disease that can be identified. The process of disability determination requires physicians to make determinations that cannot be based on medical science and for which they have no specialized training. The combination of pseudodiagnosis and pseudodisability is likely to bankrupt countries that do not recognize this folly and design more productive health and disability systems. Physicians need much more education about human behavior and the highly variable relationships among disease, distress, and disability.

Behavior↗
PubMed1996

Spinal opioid infusions in the treatment of chronic pain of nonmalignant origin.

OBJECTIVE: To review the published literature on the use of spinal opioids in the treatment of chronic pain due to nonmalignant diseases. DESIGN: Literature review. RESULTS: Ten studies describing 146 patients have been located and reviewed. The data are insufficient to permit formal analysis. CONCLUSION: The proper role of intraspinal opioids in the treatment of chronic pain not due to cancer cannot be determined from the existing literature. Intraspinal opioids should be considered an experimental procedure for chronic pains not due to cancer until better data can be obtained; all patients who receive such therapy should be part of a clinical protocol whose results are published. The development of standardized clinical trial methodology and case reporting protocols would facilitate this process.

Analgesia, Epidural↗
PubMed1996

The differential diagnosis of posterior plagiocephaly: true lambdoid synostosis versus positional molding.

The diagnosis and treatment of posterior plagiocephaly is one of the most controversial aspects of craniofacial surgery. The features of true lambdoid synostosis versus those of deformational plagiocephaly secondary to positional molding are inadequately described in the literature and poorly understood. This has resulted in many infants in several craniofacial centers across the United States undergoing major intracranial procedures for non-synostotic plagiocephaly. The purpose of this study was to describe the detailed clinical, imaging, and operative features of true lambdoid synostosis and contrast them with the features of positional plagiocephaly. During a 4-year period from 1991 to 1994, 102 patients with posterior plagiocephaly were assessed in a large multidisciplinary craniofacial program. During the same period, 130 patients with craniosynostosis received surgical treatment. All patients were examined by a pediatric dysmorphologist, craniofacial surgeon, and pediatric neurosurgeon. Diagnostic imaging was performed where indicated. Patients diagnosed with lambdoid synostosis and severe and progressive positional molding underwent surgical correction using standard craniofacial techniques. Only 4 patients manifested the clinical, imaging, and operative features of unilambdoid synostosis, giving an incidence among all cases of craniosynostosis of 3.1 percent. Only 3 among the 98 patients with positional molding required surgical intervention. All the patients with unilambdoid synostosis had a thick ridge over the fused suture, identical to that found in other forms of craniosynostosis, with compensatory contralateral parietal and frontal bossing and an ipsilateral occipitomastoid bulge. The skull base had an ipsilateral inferior tilt, with a corresponding inferior and posterior displacement of the ipsilateral ear. These characteristics were completely opposite to the findings in the 98 patients who had positional molding with open lambdoid sutures and prove conclusively that true unilambdoid synostosis exists as a specific but rare entity. Awareness of the features of unilambdoid synostosis will allow more accurate diagnosis and appropriate treatment of posterior plagiocephaly in general and in particular will avoid unnecessary surgical intervention in patients with positional molding.

Cranial Sutures↗
PubMed1996

Hydrocephalus secondary to diffuse villous hyperplasia of the choroid plexus. Case report and review of the literature.

Diffuse villous hyperplasia of the choroid plexus, which is distinct from bilateral choroid plexus papillomas, is extremely rare and is often associated with hydrocephalus due to the overproduction of cerebrospinal fluid (CSF). The authors describe an infant with hydrocephalus, diagnosed by computerized tomography scanning, who developed ascites following placement of a ventriculoperitoneal shunt and, subsequently, demonstrated excessive CSF production when the shunt was externalized. The patient was later successfully treated by placement of a ventriculoatrial shunt. Magnetic resonance imaging demonstrated diffuse villous hyperplasia of the choroid plexus as the cause of the patient's hydrocephalus. The literature on diffuse villous hyperplasia of the choroid plexus is reviewed.

Choroid Plexus↗
PubMed1995

Incentive effects of workers' compensation benefits: a literature synthesis.

Increasingly, the health care community and public policymakers are recognizing the role of economic and psychosocial factors in disability in addition to their traditional attention to environmental, physical, and somatic influences on health and illness. In particular, current discussions of health reform include serious consideration of the integration of workers' compensation and health plan benefits. This article synthesizes what is known regarding one important aspect of health policy: the effects on disability behavior of changes in workers' compensation benefits. The best available literature reveals that an increase of 10 percent in workers' compensation benefits is related to a 1 to 11 percent increase in the frequency of workers' compensation claims and a 2 to 11 percent increase in duration per claim. The article examines the sensitivity of these parameter estimates to differences in research design and proposes an idealized study methodology that, the authors hope, would improve the precision of estimates of the incentive effects of workers' compensation payments.

Accidents, Occupational↗
PubMed1995

Spinal cord stimulation for chronic low back pain: a systematic literature synthesis.

A systematic literature synthesis was performed to analyze the long-term risks and benefits of spinal cord stimulation for patients with failed back surgery syndrome. Relevant articles were identified through a MEDLINE search (January 1966-June 1994), bibliography reviews, searches of personal files, and literature supplied by a stimulator manufacturer. Two investigators independently reviewed each article to determine whether it met the following study inclusion criteria: 1) original data on return to work, pain, medication use, reoperations, functional disability, or stimulator use after permanent implantation of spinal cord stimulators in patients with chronic low back or leg pain despite previous back surgery; and 2) follow-up > or = 30 days for all patients. Articles were excluded if data from patients with other diagnoses were mixed with (and could not be separated from) data from patients with chronic low back or leg pain, or if their data were redundant with those reported in an included article. Articles written in languages other than English or French were excluded. Thirty-nine studies, all case studies, were analyzed. At follow-up (mean, 16 mo; range, 1-45 mo), an average of 59% of patients had > or = 50% pain relief (range, 15-100% of patients). Complications occurred in 42% of patients but were generally minor. It seems that approximately 50 to 60% of patients with failed back surgery syndrome report > 50% pain relief with the use of spinal cord stimulation at follow-up; the lack of randomized trials precludes conclusions concerning the effectiveness of spinal cord stimulation relative to other treatments, placebo, or no treatment.

Adult↗
PubMed1994

Why does geographic variation in health care practices matter? (And seven questions to ask in evaluating studies on geographic variation).

One of the most active fields in health services research is the study of "geographic variation," or disparities in rates of certain types of health care practices among large areas (such as countries or regions of a country) or small areas (such as countries or hospital market areas); "small area analysis" in particular has received much attention in journals and the popular press. Increasingly, data upon which to base studies of geographic variation are becoming available. This article poses questions to ask in applying studies on geographic variation to health care settings. Because findings from these studies may ultimately affect patient care, the questions are important for physicians as well as health services researchers. The questions are: 1) What events are to be analyzed? 2) What geographic units are to be analyzed? 3) How good are the data? 4) Are differences in rates due to chance alone? 5) Are high rates too high? 6) How is geographic variation to be explained? 7) What is the role of "presentation style" in explaining geographic variation?

Geography↗
PubMed1994

An international comparison of back surgery rates.

SUMMARY OF BACKGROUND DATA: Although high geographic variation in back surgery rates within the United States have been documented, international comparisons have not been published. METHODS: The authors compared rates of back surgery in eleven developed countries to determine if back surgery rates are higher: 1) in the United States than in other developed countries, 2) in countries with more neurologic and orthopaedic surgeons per capita, and 3) in countries with higher rates of other surgical procedures. Data on back surgery rates and physician supply were obtained from health agencies within these eleven countries. Country-specific rates of other surgical procedures were available from published sources. RESULTS: The rate of back surgery in the United States was at least 40% higher than in any other country and was more than five times those in England and Scotland. Back surgery rates increased almost linearly with the per capita supply of orthopaedic and neurosurgeons in the country. Countries with high back surgery rates also had high rates of other discretionary procedures such as tonsillectomy and hysterectomy. CONCLUSIONS: These findings illustrate the potentially large impact of health system differences on rates of back surgery. Better outcome studies, however, are needed to determine whether Americans are being subjected to excessive surgery or if those in other developed countries are suffering because back surgery is underutilized.

Australia↗
PubMed1994

The importance of placebo effects in pain treatment and research.

OBJECTIVE: To estimate the importance and implications of placebo effects in pain treatment and research from the existing literature, with emphasis on their magnitude and duration, the conditions influencing them, and proposed explanations. DATA SOURCES: English-language articles and books identified through MEDLINE (1980 through 1993) and PsycLIT (1967 through 1993) database searching, bibliography review, and expert consultation. STUDY SELECTION: Articles were included if they pertained to the review objectives. RESULTS: Placebo response rates vary greatly and are frequently much higher than the often-cited one third. Placebos have time-effect curves, and peak, cumulative, and carryover effects similar to those of active medications. As with medication, surgery can produce substantial placebo effects, and this possibility is commonly overlooked in case series reports on back surgery. Individuals are not consistent in their placebo responses, and a placebo-responder personality has not been identified. Models advanced to explain placebo effects emphasize the role of anxiety, expectations, and learning. CONCLUSIONS: Placebo effects influence patient outcomes after any treatment, including surgery, that the clinician and patient believe is effective. Placebo effects plus disease natural history and regression to the mean can result in high rates of good outcomes, which may be misattributed to specific treatment effects. The true causes of improvements in pain after treatment remain unknown in the absence of independently evaluated randomized controlled trials.

Dose-Response Relationship, Drug↗
PubMed1994

The prevention of needless pain: research opportunities.

The prevention of needless pain must begin with the obvious: research aimed at eliminating the injuries and illnesses that cause pain. Others have been assigned such topics at this meeting, and I will not further address primary prevention of pain by the elimination of its inciting tissue damage. There are pain prevention issues that are in great need of innovative research, but a necessary first step must be epidemiologic studies of the incidence, natural history, and distribution of significant painful conditions within our population.

Humans↗
PubMed1994

Patterns in low back pain hospitalizations: implications for the treatment of low back pain in an era of health care reform.

OBJECTIVE: To examine patterns in both surgical and nonsurgical low back pain (LBP) hospitalizations through time and among geographic regions and to explore the practical implications of these patterns for health care reform. SETTING: For time trends, the U.S. (1979-1987); for geographic variations, major regions of the U.S. (1987). DATE SOURCE: The National Hospital Discharge Survey. RESULTS: Rates of both surgical and nonsurgical LBP hospitalization varied twofold among regions of the U.S., and average lengths of stay for these types of hospitalization varied considerably as well. The U.S. rate of LBP surgery increased sharply during the period covered by the study. Over the same time, the U.S. rate of nonsurgical LBP hospitalization declined, as did average lengths of stay for both types of LBP hospitalization. CONCLUSION: Wide variations in LBP hospitalization practices raise the issue of which practices are most appropriate. Outcomes research addresses this issue, as does research on patient preferences for certain types of treatment. As indicated by the increasing rate of LBP surgery, more research also needs to be done on changing physician practice style. If such research were to result in a reduction in LBP hospitalization, savings in health care costs would be considerable.

Back Pain↗
PubMed1993

Lumbar spinal fusion. A cohort study of complications, reoperations, and resource use in the Medicare population.

Regional variations in lumbar spinal fusion rates suggest a poor consensus on surgical indications. Therefore, complications, costs, and reoperation rates were compared for elderly patients undergoing surgery with or without spinal fusion. Subjects were Medicare recipients who underwent surgery in 1985, with 4 years of subsequent follow-up. There were 27,111 eligible patients, of whom 5.6% had fusions. Mean age was 72 years. Patients undergoing fusion had a complication rate 1.9 times greater than those who had surgery without fusion. The blood transfusion rate was 5.8 times greater, nursing home placement rate 2.2 times greater, and hospital charges 1.5 times higher (all P < 0.0005). Six-week mortality was 2.0 times greater for patients undergoing fusions (P = 0.025). Reoperation rates at 4 years were no lower for patients who had fusion surgery and results were similar in most diagnostic subgroups. Indications for fusion among older patients require better definition, preferably based on outcomes from prospective controlled studies.

Aged↗