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Biomedical subjects

R J Ackermann

Publications and source records attributed to R J Ackermann.

35 records · Page 2Linked to original sources
PubMed1995

Surgery in nonagenarians: morbidity, mortality, and functional outcome.

BACKGROUND: There are few studies that document the outcomes experienced by very old patients who undergo major surgery. METHODS: This is a case series and 7-year follow-up of 116 consecutive patients who were aged 90 years or older and underwent major surgery at a large university-affiliated community hospital. We describe the functional status, short- and long-term mortality, and predictors of mortality in this group of frail elders. RESULTS: The 116 nonagenarians in this study underwent 134 major operations. Sixty-three patients were admitted to the hospital from a nursing home. The most common surgical procedures were for hip fracture, lower extremity amputation, and abdominal problems. Nineteen patients died in the hospital following surgery, and 23 patients died within 30 days of operation. Follow-up at 7 years revealed that all but three patients had died. Survival was worse for patients admitted from nursing homes, those who were nonambulatory before surgery, and those with major or complete functional impairment. CONCLUSIONS: Major surgery in nonagenarians is associated with a 20% perioperative mortality. Functional status and ambulatory ability are maintained in most patients. Whether to operate on these frail elders is a complex decision.

Aged↗
PubMed1994

Hepatic radioembolization with yttrium-90 containing glass microspheres: preliminary results and clinical follow-up.

UNLABELLED: The treatment of hepatic tumors remains unsatisfactory. These lesions receive most of their blood supply from the hepatic artery, therefore the hepatic artery administration of beta-emitting particulate radiopharmaceuticals is an attractive approach to deliver therapeutic irradiation to the liver and differentially to tumors within the liver. METHODS: A Phase I dose escalation study of the hepatic tolerance to radiation delivered by 90Y containing glass microspheres was carried out in 24 patients with hepatic malignancy. Doses of 90Y microspheres to achieve an estimated whole-liver nominal absorbed radiation dose of 5000 cGy (two patients), 7500 cGy (six patients), 10,000 cGy (seven patients), 12,500 cGy (six patients), and 15,000 cGy (three patients) were administered via the hepatic artery. The administered nominal absorbed radiation dose (NARD) was estimated based on liver volume determined from CT scans and the assumption of uniform distribution of microspheres throughout the liver. RESULTS: No hematologic, hepatic or pulmonary toxicity was encountered in the dose range examined during a mean follow-up period of up to 53 mo. Reversible gastritis or duodenitis was encountered in four patients without imaging or biopsy evidence for extrahepatic deposition of microspheres. Response data, based on CT scans obtained 16 wk after treatment, showed progressive disease in eight patients, stable disease in seven patients, minimal response in four patients and partial response in five patients. Subsequent follow-up revealed three long-term survivors at 204, 216 and 228 wk. CONCLUSIONS: These preliminary data demonstrate that in the examined dose range, radiation may be safely delivered to liver tumors by means of 90Y glass microspheres with encouraging response data.

Adult↗
PubMed1994

Adrenal disorders: know when to act and what tests to give.

Adrenal diseases are uncommon in older patients but can present insidiously. Adrenal masses are often discovered incidentally on abdominal CT scans and are usually benign, but they should be assessed for hormone production. Cushing's syndrome, or cortisol excess, is usually due to exogenous corticosteroids or a hormonally active tumor. The overnight dexamethasone suppression test is an excellent screening test. Adrenal insufficiency can be caused by hemorrhage, tuberculosis, or metastatic cancer. Maintaining a high index of suspicion of hidden adrenal disease, the primary care physician should apply an efficient approach to the diagnosis and initial management of adrenal diseases in older patients.

Adrenal Gland Diseases↗
PubMed1994

In vivo mapping of cholinergic neurons in the human brain using SPECT and IBVM.

UNLABELLED: In the search for an in vivo marker of cholinergic neuronal integrity, we extended to human use the tracer (-)-5-[123I]iodobenzovesamicol (IBVM). METHODS: IBVM, an analog of vesamicol that binds to the acetylcholine transporter on presynaptic vesicles, was prepared with specific activity greater than 1.11 x 10(9) MBq mmole-1. After intravenous injection of [123I]IBVM, body distribution studies (n = 5) and brain SPECT studies (n = 5) were performed on normal human subjects (n = 10). SPECT images of the brain were collected sequentially over the first 4.5 hr following injection, and again 18 hr later. Data were realigned and transformed to stereotaxic coordinates, and localized activities were extracted for tracer kinetic analysis. The cerebral tracer input function was determined from metabolite-corrected radial arterial blood samples. The best data fit was obtained using a three-compartment model, including terms reflecting cerebral blood volume, exchange of free tracer between plasma and brain and specific binding. RESULTS: Dissociation of bound tracer was negligible for up to 4 hr. For the fitted parameters reflecting transport (K1) and binding site density index (k3), coefficients of variation were approximately 8% in cortical regions of interest. Relative distributions corresponded well with postmortem immunohistochemical values reported for the acetylcholine-synthesizing enzyme choline acetyltransferase, k3 (IBVM binding site density index), and tracer activity distribution at 22 hr, but not at 4 hr after injection. CONCLUSION: SPECT imaging of [123I]IBVM succeeds as an in vivo measure of cholinergic neuronal integrity and should be useful for the study of cerebral degenerative processes such as Alzheimer's disease.

Adult↗
PubMed1993

Uptake of 18-fluoro-2-deoxy-D-glucose by thyroid cancer: implications for diagnosis and therapy.

A patient developed a pulmonary metastasis from papillary thyroid carcinoma. This tumor concentrated relatively little 131I, but sufficient 18F-fluoro-2-deoxy-D-glucose (FDG) to be quantified and imaged by positron emission tomography. The uptake of FDG was lower on positron emission tomographic images after T4 therapy and when the serum TSH concentration was reduced to the low normal range. It may be possible to use decreases in FDG uptake by thyroid cancers, which represent declines in metabolism by the tumors, to indicate the optimum doses of T4 treatment for patients with these neoplasms. In addition, the ratio of tumor to background radioactivity was higher for FDG than for the flow agent 201Tl, so that studies with FDG may be a useful scintigraphic method for locating thyroid cancers when radioiodine imaging is unsatisfactory.

Carcinoma, Papillary↗
PubMed1990

Prognostication of recovery following stroke using the comparison of CT and technetium-99m HM-PAO SPECT.

This study investigated the possibility that a relationship between the anatomic defects observed on computed tomography (CT) and the functional defects observed on single photon emission computed tomography (SPECT) might be used as an outcome measure to predict clinical recovery from the neurologic deficits induced by stroke. Twenty-seven patients with stroke location limited primarily to cerebral cortex were included in the study: each patient underwent a cranial CT scan, 99mTc hexamethylpropyleneamineoxime SPECT cerebral perfusion scan, and an initial and 1-yr follow-up neurologic examination. A strongly positive correlation between the ratio of the SPECT to CT volume defect sizes (SPECT divided by CT) and recovery following stroke was found, such that the greater the SPECT to CT ratio, the better the subsequent recovery of neurological deficits. Discriminant function analysis revealed that the best predictor of clinical outcome following stroke was the log-transformation of SPECT divided by CT. The results suggest that the relationship between the perfusion defects and tissue loss measured by SPECT and CT imaging may have prognostic utility following stroke limited primarily to cerebral cortex.

Adult↗
PubMed1989

SPECT of the peritoneal cavity: method for delineating intraperitoneal fluid distribution.

Seventeen single-photon emission CT (SPECT) studies were performed after intraperitoneal administration of 99mTc-sulfur colloid in patients with a history of colon cancer to assess the extent of intraperitoneal fluid distribution prior to intraperitoneal chemotherapy. Planar gamma images were also obtained in all patients for correlation with the SPECT findings. Four patients had transmission CT scans of the abdomen after intraperitoneal administration of iodinated contrast material. In seven patients, repeat planar and SPECT studies were performed with the original or a different infusion volume to determine if different volumes altered the fluid distribution qualitatively or quantitatively (using a linear profile method). We found that 360 degrees peritoneal SPECT is easily performed after intraperitoneal administration of 99mTc-sulfur colloid. SPECT provides more detailed anatomic information than planar scans do. Spaces of the upper abdomen, such as the lesser sac, were resolved better with SPECT than with planar imaging. SPECT assessment of intraperitoneal fluid distribution also correlated well with transmission CT scans. Quantitative linear-profile radionuclide plots were reproducible at the same volume and showed no major differences in relative intraperitoneal fluid distribution between the 1.5- and 3.0-l infusion volumes, suggesting that the two delivery volumes were equivalent in relative distribution. SPECT appears to be a useful procedure to define the extent and location of intraperitoneally administered fluids. Thus, it may be of value in determining the intraperitoneal distribution of drugs and radiopharmaceuticals used in the treatment of intraabdominal tumors.

Adult↗
PubMed1988

Blood flow imaging of a posterior circulation stroke. Use of technetium Tc 99m hexamethylpropyleneamine oxime and single photon emission computed tomography.

Regional cerebellar perfusion was imaged using technetium Tc 99m hexamethylpropylene amine oxime and single photon emission computed tomography (HM-PAO-SPECT) in a patient with chronic left lateral medullary syndrome with contralateral weakness due to traumatically induced thrombosis of the left vertebral artery. Despite continued neurologic deficits, x-ray transmission computed tomography was normal. However, HM-PAO-SPECT demonstrated that blood flow to the left cerebellar hemisphere was significantly impaired. This abnormality was still apparent after correction for atrophy as estimated by magnetic resonance imaging. Technetium Tc 99m hexamethyl-propyleneamine oxime and single photon emission computed tomography effectively imaged regional blood flow in the vertebrobasilar circulation and appears to more clearly reflect the nature and extent of the neurologic deficit than either x-ray transmission computed tomography or magnetic resonance scanning.

Cerebrovascular Circulation↗
PubMed1988

SPECT imaging of moyamoya disease using 99mTc-HM-PAO. Comparison with computed tomography findings.

99mTc-HM-PAO was used to evaluate regional cerebral blood flow in a 26-year-old woman with Moyamoya disease. This patient had an 18-month history of recurrent neurologic deficits and had angiographic evidence of Moyamoya disease. She had used oral contraceptives and cigarettes, but had no other risk factors for stroke. Single photon emission computed tomographic images showed bilateral and asymmetric reductions in blood flow to anterior and lateral brain regions. These findings correlated better with clinical symptomatology and suggested more extensive brain involvement than did computed tomography.

Adult↗
PubMed1985

The use of a vasoconstrictor to improve tumour blood flow in intra-arterial chemotherapy: preliminary report.

The effectiveness of intra-arterial chemotherapy is dependent on a high tumour to normal blood flow ratio (T/NT). This report demonstrates the use of a vasoconstrictor (NE) to improve the relative blood flow to head and neck tumours by causing vasoconstriction and decreased blood flow to normal soft tissue. Five quantitative planar Tc-MAA perfusion studies were performed on three patients with increasing dose rates of norepinephrine (NE) to determine the optimal dose in each patient that would produce the best T/NT. All patients demonstrated a change in perfusion pattern with increasing dose rates (0.1 to 15 micrograms min-1), although there was considerable variation between patients. Quantitative SPECT was performed on two patients. In one, there was a 35% increase in the T/NT and a 16% decrease in arteriovenous (A-V) shunting to the lung.

Antineoplastic Agents↗
PubMedDate not supplied

Performance of gastrointestinal tract endoscopy by primary care physicians. Lessons from the US Medicare database.

Primary care physicians, including family physicians, often perform flexible sigmoidoscopy in their clinical practices. It is unknown how many of these and other endoscopic procedures, such as esophagogastroduodenoscopy and colonoscopy, are performed by these physicians. Therefore, physician reimbursement by the Medicare program was documented for selected endoscopic procedures during the calendar year 1993. Family physicians and general practitioners in the United States were reimbursed for 125,821 flexible sigmoidoscopies, 21,070 upper gastrointestinal tract endoscopic procedures, and 23,841 colonoscopies. General internists performed considerably more endoscopic procedures than did family physicians. Primary care physicians performed 44% of the reimbursable flexible sigmoidoscopies, 17% of upper gastrointestinal tract endoscopies, and 15% of colonoscopies in this patient group. In 1993, primary care physicians generated a total of $175 million in allowed charges by the Medicare program for gastrointestinal tract endoscopic procedures, of which $22.6 million was to general practitioners and family physicians. Family physicians, on average, charged less for gastrointestinal tract endoscopic procedures than did other physician specialists. Primary care physicians, especially general internists, are providing substantial numbers of gastrointestinal tract endoscopic services to their patients. As Medicare does not generally reimburse physicians to perform flexible sigmoidoscopy for colorectal cancer screening, it is likely that primary care physicians performed considerably more procedures than were documented in this study.

Colonoscopy↗
PubMedDate not supplied

Medical consultation for the elderly patient with hip fracture.

BACKGROUND: This article describes a family physician geriatrician's perspective on the comprehensive management of hip fracture in frail elderly patients. Primary care physicians might be called upon to provide medical consultation for these patients. METHODS: Guidelines were developed by a combination of personal experience in consulting for several hundred elderly patients with hip fracture at a large community hospital, literature review using the key words "hip fractures," "aged," and "aged, 80 and over," and educational presentations for family practice residents. RESULTS AND CONCLUSIONS: Elderly patients with hip fracture offer a prime opportunity for comprehensive geriatric assessment. Intertrochanteric fractures are almost always treated with internal fixation, whereas femoral neck fractures can be treated by either fixation or by hemiarthroplasty. Hip fracture should be regarded as a surgical urgency, and generally operation should not be delayed, even if patients have serious comorbidity. The family physician can be instrumental in preparing the patient for surgery, preventing and treating complications, and assisting in the placement and rehabilitation of patients after hospital discharge.

Aged↗
PubMedDate not supplied

SPECT instrumentation.

The sensitivity of conventionally collimated SPECT systems is essentially fixed by the number of resolution elements desired. A variety of collimation methods are proposed or in use that distribute sensitivity and resolution differently among the various projection elements, but the effects on image quality have not really been documented. Of the many existing systems, the camera-based systems, which are useful for both head and body imaging, will be most useful in a clinical environment. For brain imaging, it is clear that fan beam collimation offers a large performance advantage over parallel collimation. However, comparison of the various instruments based on specifications alone is difficult if not impossible, and careful 3-dimensional imaging studies are an absolute necessity. In view of the fairly healthy price of dedicated brain instruments, it is interesting to speculate on their role in nuclear imaging. Their cost is from $50,000 to $200,000 less than a multi-headed general purpose system, and they have excellent resolution and sensitivity for brain imaging. They cost from $175,000 to $300,000 more than a single head camera-computer system yet offer 3 to 4 times the resolution-adjusted sensitivity. This suggests that a special purpose instrument would need to be heavily utilized or located (physically or politically) where the body imaging capability of a two or three-headed system would not be used. A good case might be made for locating a dedicated instrument in a neurological ICU in order to avoid transporting critically ill patients out of the unit. The various non-conventional imaging methods show promise for exceeding the sensitivity limit of regular collimators. At present it is speculative as to how much can be gained and whether it will be worth the added complexity and/or cost. Nevertheless, they are very interesting and certainly justify additional research.

Brain↗
PubMedDate not supplied

Reducing polypharmacy in the nursing home: an activist approach.

BACKGROUND: Nursing home patients generally take many medications and are at risk for drug side effects and interactions. These patients are often frail, have multiple medical problems, and many have severe cognitive deficits. METHODS: Recommendations for reducing polypharmacy in nursing home patients were formulated based upon a review of the medical literature. In many cases, studies of nursing home patients have not been done, and data are extrapolated from other populations. RESULTS AND CONCLUSIONS: The family physician should actively attempt to reduce the nursing home patient's drug list to those drugs that are most likely to improve or maintain function. Anticonvulsants and antiarrhythmics often can be withdrawn, and medications for angina and hypertension might be simplified. Drugs used solely for prevention, such as lipid-lowering agents or anticoagulants, might not have a favorable impact on patients with limited life expectancies. Careful review of the medication list could prevent iatrogenic complications and maximize function in nursing home patients.

Aged↗