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Biomedical subjects

A H Tzamaloukas

Publications and source records attributed to A H Tzamaloukas.

At least 19 recordsLinked to original sources
PubMed1992

Pitfalls of bone mineral density evaluation by dual-photon absorptiometry.

Material absorbing photons aligned with the lumbar vertebrae can create falsely elevated measurements of bone mineral density during dual-photon absorptiometry. Three cases illustrating this phenomenon are presented. Although bone mineral density was overestimated in each case, calculated fracture risk was normal in two cases and greatly increased in the third. Photon-absorbing material can create overestimates of bone mineral density during dual-photon absorptiometry, even when a greatly increased fracture risk is computed.

Absorptiometry, Photon↗
PubMed1992

CAPD in end stage patients with renal disease due to diabetes mellitus--an update.

Large numbers of diabetics with renal failure have been treated by continuous ambulatory peritoneal dialysis (CAPD). Overall 1-year patient survival varies from 51% to 87%. Mortality is due to cardiovascular disease in more than 50% of the cases. Young diabetics with good blood pressure control and without cardiac disease have a chance at long survival on CAPD. In comparison to hemodialysis, CAPD yields better patient survival for young diabetics and worse for old diabetics, worse technique survival, probably greater overall morbidity, and similar rates of progression of retinopathy, neuropathy and peripheral vascular disease. Adequacy of peritoneal clearance and peritoneal ultrafiltration characteristics are similar between diabetics and non-diabetics on CAPD. CAPD is associated with better preservation of renal function than hemodialysis in diabetics. The rates of CAPD peritonitis do not differ substantially between diabetics and non-diabetics. However, diabetes appears to be associated with higher incidence of tunnel infection. Hyperlipidemia is generally less severe in diabetics than non-diabetics on CAPD, but malnutrition is more frequent in diabetics. CAPD has many attractive features and several drawbacks for the management of diabetics with end stage renal failure (ESRF). Its ultimate success will depend on the outcome of efforts to improve cardiovascular mortality, malnutrition, hyperlipidemia and catheter-related infections.

Adolescent↗
PubMed1992

Metabolic differences between persistent and routine peritonitis in CAPD.

Changes in 10 metabolic parameters (body weight, blood hemoglobin, and serum albumin, urea, creatinine, cholesterol, triglycerides, potassium, calcium and phosphorus) were compared in 28 episodes of routine peritonitis and 27 episodes of persistent peritonitis. These infections occurred in 20 CAPD patients, all of whom acquired both types of peritonitis on separate occasions. Coagulase-negative staphylococci predominated in the routine infections, while Staphylococcus aureus and Gram-negative bacilli, especially Pseudomonas, were associated with persistent peritonitis. Decreases during infection were significantly larger in persistent as compared with routine peritonitis episodes for all 10 nutritional parameters. Time required for recovery of all nutritional variables except serum potassium and urea was significantly longer in the persistent episodes. Persistent peritonitis led to peritoneal catheter loss in 13 of the 27 episodes and was associated with 4 deaths, while routine peritonitis was associated with neither catheter loss nor death. In contrast to routine peritonitis, persistent CAPD peritonitis is associated with severe malnutrition, considerable morbidity, and mortality.

Blood Proteins↗
PubMed1992

Hypoglycemia in diabetics on dialysis with poor glycemic control: hemodialysis versus continuous ambulatory peritoneal dialysis.

Eight diabetic men with poor glycemic control, probably worsened by severe congestive heart failure and gastroparesis, were sequentially dialyzed by CAPD and hemodialysis. Mean blood glucose concentration, blood glycosylated hemoglobin, and insulin dose were higher during CAPD than during hemodialysis. Among blood glucose determinations, however, the frequency of hypoglycemia (glucose less than 3.3 mmol/L) was higher during hemodialysis (13.2 +/- 8.9%) than during CAPD (2.8 +/- 2.1% p = 0.012), whereas the frequencies of hyperglycemia (glucose greater than 11.1 mmol/L) and euglycemia (glucose between 3.5 and 11.1 mmol/l) did not differ between the two dialysis modalities. Furthermore, hypoglycemia was severe during hemodialysis and was associated with two deaths. There were no deaths linked to abnormalities in blood glucose concentration during CAPD. When hypoglycemia is frequent in diabetics with poor glycemic control, CAPD is preferable to hemodialysis.

Blood Glucose↗
PubMed1991

Understanding serum electrolytes. How to avoid mistakes.

Serum electrolyte levels by themselves may be difficult to interpret. For example, an abnormal serum potassium concentration cannot be understood without taking into account the patient's history, other serum electrolyte values, and possibly results of other laboratory tests. Knowledge of the principles of serum electrolyte concentrations, therefore, is an important adjuvant to understanding their implications.

Adult↗
PubMed1991

Factors affecting bone mineral density in elderly men receiving chronic in-center hemodialysis.

Twenty-five elderly men receiving chronic hemodialysis had measurements of their bone mineral density (BMD) by dual-photon absorptiometry (DPA). Loss of BMD was much more pronounced in femoral necks than in lumbar vertebrae. Stepwise multiple liner-regression analysis showed that low BMD was associated with 1) hypoalbuminemia, hypermagnesemia, hyperaluminemia, and high serum alkaline phosphatase for femoral necks and 2) hypercalcemia and hypermagnesemia for lumbar vertebrae. These observations suggest that the femoral neck is the preferred site for measurement of BMD in dialysis patients. Along with factors directly affecting bone metabolism, nutritional factors may affect BMD in such patients.

Absorptiometry, Photon↗
PubMed1991

Carpal tunnel syndrome, subclinical median mononeuropathy, and peripheral polyneuropathy: common early complications of chronic peritoneal dialysis and hemodialysis.

Nerve conduction velocity studies were done in median, ulnar, and peroneal nerves, one time each in 46 patients who had been on chronic peritoneal dialysis or hemodialysis for varying lengths of time. Only six patients had normal findings; 37 had peripheral polyneuropathy (15 had isolated polyneuropathy; 22 had median nerve dysfunction in addition); 16 had subclinical median mononeuropathy (14 with polyneuropathy, two without); and nine had overt carpal tunnel syndrome (eight with polyneuropathy, one without). Abnormalities were present in seven of the 11 patients studied after one year of dialysis and in 19 of the 24 patients studied after two years of dialysis. Seventeen patients studied after five years of dialysis all had polyneuropathy. Nine patients studied after seven years of dialysis all had median nerve dysfunction. Abnormalities were as common with peritoneal dialysis as with hemodialysis. Nerve dysfunction was independent of the disease underlying renal failure, the side of the dialysis access shunt, and the presence or absence of osteodystrophy. Dialysis patients need frequent nerve conduction studies from the onset of dialysis to identify carpal tunnel syndrome early and to avoid irreversible nerve damage.

Carpal Tunnel Syndrome↗
PubMed1991

Subcutaneous versus intraperitoneal insulin in the management of diabetics on CAPD: a review.

Intraperitoneal and subcutaneous routes of administration for diabetics on CAPD were compared. The comparison included: (1) Control of blood glucose concentration: both methods can provide satisfactory glycemic control for most patients. Changing the method of insulin administration is warranted when one method fails. (2) Effect on plasma insulin levels: intraperitoneal administration can produce a plasma insulin profile similar to the normal profile. This is unusual with subcutaneous administration. Consequences of hyperinsulinemia (hyperlipidemia, hypertension) seem, however, to be similar between the two methods of insulin administration. (3) Effect on peritoneal permeability: permeability characteristics are maintained unchanged, usually, with either method after long-term CAPD. However, insulin is mitogenic in vitro. Theoretically, intraperitoneal insulin could lead to peritoneal fibrosis. (4) Effect on infectious complications of CAPD: a difference in the rate of peritonitis or overall PD catheter-related infections has not been convincingly demonstrated between the two methods of insulin administration. Exit site and tunnel infections with staphylococcus aureus may be more frequent in diabetics receiving insulin subcutaneously. (5) Effect on hepatic structure and function: subcapsular hepatic steatosis was described in diabetics receiving insulin intraperitoneally. The clinical significance of this finding remains to be demonstrated. We conclude that both methods can be applied for insulin administration in diabetics on CAPD. The intraperitoneal method should be tried first in most instances. Prospective studies comparing the two methods are needed.

Diabetes Mellitus, Type 1↗
PubMed1991

Reaction of patients on chronic dialysis to discussions about cardiopulmonary resuscitation.

A total of 146 patients, 91 on chronic hemodialysis and 55 on chronic peritoneal dialysis, were asked to declare their choice of cardiopulmonary resuscitation (CPR) in cases of cardiopulmonary arrest. Fifty-four patients (37%) declined CPR. The severity of medical disability and the presence of diabetes were independent predictors of refusal of CPR. The pattern of patient reaction to CPR gave valuable information about patients' comprehension of this issue and about patients' ability to cope emotionally with CPR. On the basis of the reaction pattern, approximately 95% of the patients interviewed understood CPR and reacted to it appropriately. Questioning dialysis patients about their CPR preference is feasible and fruitful.

Adult↗
PubMed1991

Intraperitoneal thrombolytic agents in relapsing or persistent peritonitis of patients on continuous ambulatory peritoneal dialysis.

Urokinase or streptokinase was instilled intraperitoneally as an adjunct to the antibiotic therapy in 16 episodes of relapsing or persistent peritonitis in CAPD patients. In eight patients the combination of antibiotics and intraperitoneal thrombolytic agents resulted in clearing of the infection with no recurrences. The treatment failed in eight other patients, who had their peritoneal catheters removed. Six of the last eight patients had either abdominal wall abscesses or persistence of the bacteria on the wall of the peritoneal catheter. Elevated post-intraperitoneal instillation peritoneal fluid neutrophil counts and positive post-instillation peritoneal fluid cultures predicted failure of the intraperitoneal instillation of thrombolytic agents in most instances. Intraperitoneal instillation of urokinase or streptokinase may help cure approximately 50% of the episodes of relapsing for persistent peritonitis. Post-instillation peritoneal fluid cell counts and cultures should be monitored. Radiologic investigation for abdominal wall or intraabdominal abscesses is indicated if intraperitoneal instillation of urokinase or streptokinase fails to eradicate peritonitis.

Anti-Bacterial Agents↗
PubMed1991

Bone scans in sternal osteomyelitis complicating hemodialysis blood access.

Sternal osteomyelitis complicating infection of vascular access for hemodialysis is exceedingly rare and presents serious diagnostic and therapeutic difficulties. Two hemodialysis patients with sternal osteomyelitis following vascular access infection are reported. Factors favoring sternal location of the infection included previous chest trauma in the first patient and difficult insertion of a dialysis subclavian catheter in the second patient. Indium oxine, gallium, and three-way bone scans were instrumental in establishing diagnosis and in documenting cure by prolonged antibiotic courses. Sternal scans should be performed in dialysis patients with vascular access infections and signs of sternal disease.

Aged↗
PubMed1990

Diagnosis and management of bone disorders in chronic renal failure and dialyzed patients.

Renal osteodystrophy is multifactorial. Decreased calcium absorption from the GI tract, secondary to low calcitriol levels; hyperphosphatemia; skeletal resistance to the action of parathormone; and aluminum deposition on the surface of the bones are its main pathogenetic mechanisms. Its biochemical features include abnormalities in serum calcium, phosphate, alkaline phosphatase, parathormone, calcitriol, and aluminum concentration. Radiographic methods are of little use in the characterization of the type of osteodystrophy present, but they may be of help in assessing mineral loss from the skeleton. Clinical manifestations are from bones (pain, deformities, fractures) or from metastatic calcifications. Bone biopsy is the definitive means of diagnosis. The main histologic types of osteodystrophy include osteitis fibrosa, osteomalacia, mixed form (with features of both osteitis fibrosa and osteomalacia), and aluminum osteodystrophy (presenting as either osteomalacia or aplastic lesion). The management of renal osteodystrophy should address all the pathogenetic mechanisms. Correction of the abnormalities in calcium and phosphate metabolism and prevention of aluminum osteodystrophy are the cardinal rules of management. Specific measures (parathyroidectomy, chelation of aluminum) have clear-cut indications and usually require a bone biopsy.

Aluminum↗
PubMed1990

Nephrotic syndrome and rapid renal failure in autosomal dominant polycystic kidney disease.

A 44-year-old man, with autosomal dominant polycystic kidney disease and hypertension under satisfactory control, developed nephrotic syndrome with negative serology. Open renal biopsy revealed focal glomerular sclerosis. Prior to the appearance of heavy proteinuria, serum creatinine was 1.7 mg/dl. After the nephrotic syndrome had been established, renal function deteriorated rapidly and hemodialysis was started within 2.6 years. In patients with autosomal dominant polycystic kidney disease, the appearance of nephrotic range proteinuria along with a rapid decline in renal function indicates the presence of a glomerular lesion, which needs to be investigated by renal biopsy.

Adult↗